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Decompression system, method and process for reducing pressure of high-pressure aerosol

发布日期:2020-01-07 13:12 Document serial number: 19641809 Release date: 2020-01-07 13:12
Decompression system, method and process for reducing pressure of high-pressure aerosol

The present subject matter relates generally to a system and method for reduced pressure, thus to reduce the pressure of the aerosol flow from the high pressure environment, such may be sampling the representative nonvolatile particle concentration flows.



Background technique:

The exhaust of a gas turbine engine contains combustion byproducts. Exemplary combustion byproducts including sulfur dioxide, carbon dioxide, nitrogen oxides and particulate matter, including volatile and non-volatile particulate matter. The most common substance in non-volatile particulates is black carbon (commonly referred to as carbonaceous soot). Black carbon is formed by incomplete combustion of fuel. Other non-volatile particulate matter can include dust, metal and ceramic particles. Non-volatile particulate matter can have a negative impact on human health and the environment.

Therefore, reducing the negative effects of such combustion by-products, especially non-volatile particulate matter, has become a common goal. In general, to study non-volatile particulate matter from aerosol streams, samples are taken from these streams and a particulate matter measurement device is used to measure various parameters of the non-volatile particulate matter, including, for example, particle mass concentration, number concentration, and particle size distribution Wait. Obtaining a sample from this high-pressure aerosol stream that represents the actual nonvolatile particulate matter concentration has presented certain challenges.

One challenge in obtaining a sample representative of the actual non-volatile particulate matter concentration is to generate an exhaust aerosol flow in a high pressure environment (eg, a burner component of a gas turbine engine). For existing particle measurement devices that accurately measure non-volatile particulate matter, the pressure of the aerosol exhaust stream must be reduced to or near ambient pressure. Although the traditional decompression system can reduce the pressure of the aerosol stream to the ambient pressure, when the pressure of the aerosol stream is reduced to the ambient pressure, the traditional system greatly changes or changes the concentration of the non-volatile particulate matter. Therefore, when a sample from an aerosol flow is measured by a particle measurement device, the measurement may not represent the particulate environment present under high pressure.

Since conventional pressure reduction systems have been unsuccessful in reducing the pressure of an aerosol stream without affecting or minimizing the nonvolatile particulate matter concentration of this stream, for gas turbine engine designers, successful measurements It is challenging to characterize the non-volatile particulate matter of this aerosol exhaust stream. Therefore, validating new emission reduction designs, testing engines in use, modeling "particulate emission reductions", and characterizing transfer functions between aerosol sources (e.g., burners) and typical measurement planes required by certification bodies are particularly Challenging.

Therefore, decompression systems and methods that address one or more of the challenges described above would be useful.



Technical realization elements:

Aspects and advantages of the present invention will be set forth in part in the following description, or may be apparent from the description, or may be learned by practicing the present invention.

In one aspect, the disclosure relates to a reduced pressure system. The decompression system includes a housing defining a first chamber and a second chamber positioned downstream of the first chamber. The decompression system further includes an inlet port fluidly connecting the high-pressure environment and the first chamber. The inlet port defines a first expansion hole, and an aerosol stream composed of non-volatile particles is transferred from the high-pressure environment to the first chamber through the first expansion hole, wherein The aerosol flow has a first pressure drop from high to medium pressure after passing through the first expansion hole. In addition, the decompression system includes a transition tube fluidly connecting the first and second chambers, the transition tube defining an inlet and a second expansion hole, and the aerosol flow is delivered from the first chamber to the second chamber through the second expansion hole, wherein the aerosol The flow has a second pressure drop from medium pressure to low pressure after passing through the second expansion hole. In addition, the reduced pressure system includes a sample outlet port defining a sample outlet of the second chamber, wherein a portion of the aerosol flow having a low pressure is configured to flow through the sample outlet.

In another aspect, the invention relates to a method for reducing the pressure of an aerosol stream composed of non-volatile particles from a high pressure to a low pressure. The method includes expanding an aerosol flow through a first expansion hole into a first chamber defined by a housing to reduce the aerosol flow from a high pressure to a medium pressure. The method also includes expanding the aerosol flow through a second expansion hole defined by the transition tube into a second chamber defined by the housing to reduce the aerosol flow from medium pressure to low pressure, wherein the transition tube is completely contained within the housing.

In another aspect, the invention relates to a decompression system. The decompression system includes a housing formed at least partially of a conductive material and defining a first chamber and a second chamber, the second chamber being located downstream of the first chamber. In addition, the pressure reduction system includes an inlet port fluidly connecting the high-pressure environment and the first chamber. The inlet port defines a first expansion hole, and an aerosol stream composed of non-volatile particles is transferred from the high-pressure environment to the first chamber through the first expansion hole. The aerosol flow has a first pressure drop from high pressure to medium pressure after passing through the first expansion hole. In addition, the pressure reduction system includes an overflow pressure valve fluidly connected to the first chamber for selectively adjusting the pressure of the aerosol flow in the first chamber. The decompression system also includes a transition tube formed of a conductive material and fluidly connected to the first and second chambers and mounted to the housing. The transition tube defines an inlet and a second expansion hole, and the aerosol flow passes through the second expansion hole from the first One chamber is delivered to the second chamber, where the aerosol stream has a second pressure drop from medium pressure to low pressure after passing through the second expansion orifice. In addition, the pressure reduction system includes a heating assembly for supplying heat to the housing. The reduced pressure system further includes a sample outlet port defining a sample outlet of the second chamber, wherein a portion of the aerosol flow having a low pressure is configured to flow through the sample outlet.

These and other features, aspects and advantages of the present invention will be better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A complete and workable disclosure of the present invention, including its best mode, is set forth in the description, to those of ordinary skill in the art, with reference to the accompanying drawings, in which:

FIG. 1 provides a perspective view of an exemplary decompression system according to an exemplary embodiment of the present disclosure;

Figure 2 provides a perspective view of the pressure reduction system of Figure 1, depicting the heating element being removed to expose the housing of the pressure reduction system;

FIG. 3 provides a cross-sectional view of the decompression system taken along line 3-3 in FIG. 1;

FIG. 4 provides a close-up cross-sectional view of the inlet port of the pressure reduction system as viewed at section 4 of FIG. 3;

FIG. 5 provides a close-up cross-sectional view of the transition tube of the decompression system as viewed at section 5 of FIG. 3;

Figure 6 provides a side view of the transition tube of Figure 5;

FIG. 7 provides a cross-sectional view of the transition tube taken along line 7-7 in FIG. 6; and

FIG. 8 provides a flowchart of an exemplary method for reducing the pressure of an aerosol stream composed of non-volatile particles from a high pressure to a low pressure according to an exemplary aspect of the present disclosure.

detailed description

Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to explain the present invention and not to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Accordingly, the invention is intended to cover such modifications and variations as fall within the scope of the appended claims and their equivalents. Further, as used herein, approximate terms, such as "approximately," "essentially," or "approximately," mean within an error range of ten percent (10%). In addition, as used herein, the terms "first", "second", and "third" are used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of each component . The terms "upstream" and "downstream" refer to the relative directions of fluid flow in the fluid path. For example, "upstream" refers to the direction in which the fluid flows, and "downstream" refers to the direction in which the fluid flows.

In general, the present disclosure relates to a pressure reduction system and method, and thus is used to reduce the pressure of a high-pressure aerosol, for example, to ambient pressure without significantly altering the characteristics of the aerosol. In this way, the non-volatile particulate matter concentration in the sample stream obtained from the aerosol stream at ambient pressure represents the non-volatile particulate matter concentration present in the aerosol stream under high pressure before the pressure is reduced. These representative samples can be used to measure various properties of non-volatile particles of high-pressure aerosols.

In an exemplary aspect, a reduced-pressure system is provided. Decompression systems include features that reduce the pressure of high-pressure aerosols to ambient pressure without significantly altering aerosol characteristics. In particular, the pressure reduction system includes two expansion holes, which reduce the pressure of the aerosol flow in two stages. The aerosol is directed from a high pressure environment (eg, a burner assembly of a gas turbine engine) through a first expansion hole defined by an inlet port and into a first chamber defined by a housing, thereby expanding the aerosol flow. As the aerosol expands, the high-pressure aerosol decreases to medium pressure and the temperature also decreases. A transition tube fluidly connecting the first chamber with the second chamber defined by the housing receives a portion of the aerosol flow. As the aerosol flows through the transition tube, the transition tube stabilizes the flow and exchanges heat with the gas aerosol. Flow heating facilitates constant volume flow rate (or near constant volume flow rate) through the system and prevents the formation of condensation along the gas path of the system. The aerosol is directed through a second expansion hole defined by the transition tube at its downstream end and into the second chamber. Therefore, the aerosol flow expands again, thereby reducing the pressure of the aerosol flow from the intermediate pressure (the pressure of the aerosol flow upstream of the second expansion hole and downstream of the first expansion hole) to a low pressure. For example, the low pressure may be ambient pressure. A portion of the low-pressure aerosol can then be directed to a particulate matter measurement device, which is used to measure the particles of the aerosol. The reduction of the pressure of the aerosol without significantly changing the characteristics of the aerosol is achieved by passing gas passing upstream of the second expansion hole in the transition tube (to a lesser extent, upstream of the first expansion hole at the inlet port). Constant volume flow of the aerosol with isentropic expansion of the sol and isobaric heating of the first and second expansion pores. In another exemplary aspect, a method for reducing the pressure of a high-pressure aerosol to ambient pressure using a pressure reduction system without significantly changing the characteristics of the aerosol is also provided.

Figures 1, 2 and 3 provide various views of an exemplary decompression system 100 according to an exemplary embodiment of the present disclosure. More specifically, FIG. 1 provides a perspective view of the pressure reduction system 100, FIG. 2 provides another perspective view of the pressure reduction system 100 with the heating assembly removed to expose the housing of the pressure reduction system 100, and FIG. 3 provides A cross-sectional view of the decompression system 100 taken along line 3-3 in FIG. 1. The decompression system 100 defines an axial direction a, a radial direction r, and a circumferential direction c extending around the axial direction a. The axial direction a, the radial direction r, and the circumferential direction c define a directional system. In addition, the decompression system 100 also defines a main axis m extending in the axial direction a.

As best shown in FIGS. 2 and 3, the decompression system 100 includes a housing 110 that defines a first chamber 112 and a second chamber 114. The second chamber 114 is positioned downstream of the first chamber 112. For this embodiment, the housing 110 includes a first cylinder 116 and a second cylinder 118, and the second cylinder 118 is connected to the flange 120 of the first cylinder 116. The first cylinder 116 defines a first chamber 112 and the second cylinder 118 defines a second chamber 114. However, in some embodiments, the housing 110 may be formed as a single continuous integral component. Further, for this embodiment, the housing 110 is formed at least partially from a conductive material, such as a metallic material. In a preferred embodiment, the housing 110 is formed entirely from a conductive material.

As particularly shown in FIG. 3, the inlet port 130 fluidly connects the high-pressure environment 122 and the first chamber 112. More specifically, as shown, the inlet conduit 124 fluidly connects the high-pressure environment 122 with the inlet port 130, which in turn fluidly connects the inlet conduit 124 with the first chamber 112. The high-pressure environment 122 may be any suitable high-pressure environment. For example, the high-pressure environment 122 may be a combustor component of a gas turbine engine. The inlet port 130 defines an inlet 132 and a first expansion hole 134, which is spaced apart from the inlet 132, for example, in the axial direction a. The first expansion hole 134 functions as an outlet of the inlet port 130. The inlet 132 of the inlet port 130 is located upstream of the first expansion hole 134 and is fluidly connected to the inlet conduit 124. An inlet port channel 136 defined by the inlet port 130 extends between the inlet 132 and the first expansion hole 134 and fluidly connects the inlet 132 and the first expansion hole 134. During operation of the decompression system 100, an aerosol stream s composed of non-volatile particles flows through the first expansion hole 134, so that the aerosol stream s is delivered from the high-pressure environment 122 to the first chamber 112. The aerosol flow s may be an exhaust flow, such as an exhaust flow from a combustor component of a gas turbine engine.

It is worth noting that the pressure of the aerosol flow s upstream of the first expansion hole 134 indicated as high pressure p1 is higher than the pressure in the first chamber 112 and the outlet pressure of the decompression system 100, as will be explained in detail herein of. For example, the high pressure p1 may be three bars (3 bar) to about seventy bars (70 bar). In some embodiments, the high pressure p1 may even be higher than seventy bar (70 bar). When the aerosol stream s flows through the first expansion hole 134, the first expansion hole 134 reduces the pressure of the aerosol stream s from a high pressure p1 to a medium pressure p2, for example, via expansion through the first expansion hole 134. As an example, assume that the high pressure p1 of the aerosol stream s is fifty bar (50 bar). The first expansion hole 134 can reduce the pressure of the aerosol flow s to a medium pressure p2 of seven and one-tenth bar (7.10 bar). The intermediate pressure p2 represents the pressure of the aerosol flow in the first chamber 112 as shown in FIG. 3.

FIG. 4 provides a close-up view of the inlet port 130. As shown, the first expansion hole 134 has a first diameter d1. The inlet port channel 136 has a diameter dip. The inlet 132 of the inlet port 130 has the same diameter dip as the inlet port channel 136. For this embodiment, the diameter dip is at least three and a half times (3.5 times) larger than the first diameter d1. As further shown, the first conical frustum 138 defined by the inlet port 130 transitions the inlet port channel 136 to the first expansion hole 134. For this embodiment, the first conical frustum 138 transitions the inlet port channel 136 to the first expansion hole 134 at an angle θ1 of about sixty degrees (60 °) with respect to the axial direction a. Preferably, the angle θ1 is at least 45 degrees (45 °) with respect to the axial direction a. The first conical frustum 138 collects the aerosol flow s into the first expansion hole 134 and prevents the stress from rising. The first conical frustum 138 and the first expansion hole 134 form a converging throat of the inlet port 130.

Returning to FIGS. 1 to 3, as shown, the decompression system 100 includes a pressure sensing device 140 fluidly connected to the first chamber 112 for measuring or sensing the pressure of the aerosol flow s in the first chamber 112, It has a medium pressure p2 at this stage of the decompression system 100. For example, the pressure sensing device 140 may be an analog pressure gauge. As particularly shown in FIG. 3, the housing 110 defines an opening 142. The inlet of the conduit 144 is positioned in the opening 142 and extends outward from the first chamber 112 in the radial direction r to fluidly connect the pressure sensing device 140 with the first chamber 112.

The pressure reduction system 100 further includes an overflow pressure valve 150. Specifically, for this embodiment, the pressure reduction system 100 includes a pair of relief pressure valves 150 (FIG. 2). In some embodiments, the pressure reduction system 100 may include more than two (2) valves or only one (1) relief pressure valve 150. Each relief pressure valve 150 is fluidly connected to the first chamber 112 for selectively adjusting the pressure of the aerosol flow s within the decompression system 100 (more specifically, within the first chamber 112). In other words, each of the relief pressure valves 150 is movable between an open position and a closed position, and in the case of a pressure exceeding a predetermined set pressure in the first chamber 112, one or more of the relief pressure valves 150 Move to the open position to remove a portion of the aerosol stream s from the first chamber 112 to reduce the pressure therein. In a case where the pressure in the first chamber 112 is at or below a predetermined set pressure, the relief pressure valve 150 may be moved to a closed position. The relief pressure valve 150 can be moved between an infinite number of open and closed positions, for example by using a proportional control valve, or it can be switched between a single open position and a closed position. The first chamber 112 defines a pair of outlets 152 (only one is shown in FIGS. 3 and 5), which allow excess portions of the aerosol flow s to leave the first chamber 112 and flow downstream to the overflow pressure valve 150.

In addition, for this embodiment, the decompression system 100 includes a heating assembly 160. The heating assembly 160 is configured to selectively heat the housing 110 to a predetermined set temperature. Advantageously, the housing 110 is heated by the heating assembly 160 to prevent or minimize condensation during expansion of the aerosol stream s after flowing through the first expansion hole 134 and the second expansion hole, as will be explained further below. In some embodiments, the heating assembly 160 is configured to maintain the temperature within plus or minus five degrees Celsius (5 ° C) of a predetermined set temperature. In some embodiments, the predetermined set temperature is set between one hundred degrees Celsius (100 ° C) and about two hundred and fifty degrees Celsius (250 ° C). In some preferred embodiments, the predetermined set temperature is set at about one hundred and fifty degrees Celsius (150 ° C).

The heating assembly 160 may include various components for heating the housing 100. For example, in some embodiments, the heating assembly 160 includes one or more heating elements (eg, a resistance heater), and an insulator wound around the housing 110. In addition, the heating assembly 160 may include one or more fans to move relatively hot air across the surface of the housing 110.

As best shown in FIGS. 1 and 3, for this embodiment, the heating assembly 160 includes a heating jacket 162 wound around the housing 110. Preferably, the heating jacket 162 is completely wound around the casing 110 in the circumferential direction c (ie, surrounding the casing 110). Moreover, in some preferred embodiments, the heating jacket 162 is wound around the housing 110 along the entire axial length of the housing 110, for example, as shown in Figs. The heating jacket 162 may be formed of any suitable material having high thermal insulation properties, such as glass wool. The heating jacket 162 also includes one or more suitable heating elements. For example, in some embodiments, the heating jacket 162 includes a plurality of electric wires, and when a current is passed, the plurality of electric wires discharge heat. Additionally or alternatively, in some embodiments, the heating jacket may include one or more fluid conduits configured to carry a relatively warm fluid therethrough to heat the housing 110.

In addition, the decompression system 100 includes one or more controllers 170 or computing devices configured to control various components of the decompression system 100 as shown in FIG. 3. For example, in this exemplary embodiment, the controller 170 is communicatively coupled with the relief pressure valve 150, the pressure sensing device 140, and the heating jacket 162 of the heating assembly 160. The controller 170 may be communicatively coupled to the pressure sensing device 140, the relief pressure valve 150, the heating jacket 162, and other components of the pressure reduction system 100 in any suitable manner, such as through a suitable wired or wireless connection. In some embodiments, the pressure reduction system 100 may include a dedicated controller 170 for controlling the heating jacket 162 and a dedicated controller 170 for controlling the relief pressure valve 150. For example, the controller 170 may control the relief pressure valve 150 based at least in part on one or more signals from the pressure sensing device 140, as will be explained more fully below. However, in some embodiments, a single controller 170 may control various aspects of the decompression system 100.

In some exemplary embodiments, the controller 170 is configured to receive, for example, one or more signals indicative of the pressure of the aerosol flow s within the first chamber 112 from the pressure sensing device 140. The controller is then configured to determine whether the pressure of the aerosol flow s within the first chamber 112 is within a predetermined range of the set pressure. The predetermined range may be static or dynamic. For example, the predetermined range may be based at least in part on a set pressure, which may be dynamically changed to achieve a particular pressure at the outlet of the pressure reduction system 100. The set pressure may be changed to accommodate fluctuations in the pressure of the aerosol flow s flowing upstream of the inlet port 130 to the decompression system 100. The controller 170 is also configured to control the overflow pressure valve 150 to adjust the overflow based at least in part on whether the pressure (for example, the intermediate pressure p2) of the aerosol flow s in the first chamber 112 is within a predetermined range of the set pressure. Valve position of the pressure valve 150. For example, if the pressure p2 of the aerosol flow s in the first chamber 112 is greater than a predetermined range of the set pressure, the controller 170 activates or controls one or more of the relief pressure valves 150 to move to the open position. In this way, excess pressure can be discharged into the surrounding environment, thereby effectively reducing the pressure in the first chamber 112. On the other hand, if the pressure p2 of the aerosol flow s in the first chamber 112 is smaller than a predetermined range of the set pressure, the controller 170 activates or controls one or more of the relief pressure valves 150 to move to a closed state, and therefore, prevents Pressure loss in the first chamber 112.

As best shown in FIG. 3, the pressure reduction system 100 includes a transition tube 180 that fluidly connects the first chamber 112 and the second chamber 114. It is worth noting that the transition tube 180 is completely contained within the housing 110. That is, the transition tube 180 is not exposed to external elements that may negatively affect the temperature of the aerosol flow s flowing therethrough. As shown in the embodiment shown in FIG. 3, the transition tube 180 extends into the first chamber 112, enters the second chamber 114, and is positioned between the chambers 112, 114, but is still contained within the housing 110.

The transition tube 180 defines an inlet 182 and a second expansion hole 184. The second expansion hole 184 is spaced from the inlet 182 of the transition tube 180 in the axial direction a, for example. A transition channel 186 defined by the transition tube 180 extends between the inlet 182 of the transition tube 180 and the second expansion hole 184 of the transition tube 180 and fluidly connects the inlet 182 and the second expansion hole 184. An inlet 182 of the transition pipe 180 is located upstream of the second expansion hole 184. The second expansion hole 184 serves as an outlet of the transition tube 180 and an inlet of the second chamber 114. During operation of the decompression system 100, an aerosol stream s composed of non-volatile particles flows through the second expansion hole 184 such that the aerosol stream s is transported from the first chamber 112 to the second chamber 114.

As described above, the pressure of the aerosol flow s upstream of the second expansion hole 184 and downstream of the first expansion hole 134 has an intermediate pressure p2. When the aerosol stream s flows through the second expansion hole 184, the second expansion hole 184 reduces the pressure of the aerosol stream s from the intermediate pressure p2 to the low pressure p3, for example, via expansion through the second expansion hole 184. Continuing the above example, it is assumed that the intermediate pressure p2 of the aerosol stream s is seven and one-tenth bar (7.10 bar). The second expansion hole 184 may reduce the pressure of the aerosol flow s to a low pressure p3 of one bar (1 bar). The low pressure p3 indicates the pressure of the aerosol flow in the second chamber 114. At one bar (1 bar), the particle measurement device can measure the concentration of non-volatile particles in a representative sample of the aerosol stream s.

FIG. 5 provides a close-up view of the transition tube 180. As shown, the second expansion hole 184 has a second diameter d2. For this embodiment, the first diameter d1 of the first expansion hole 134 (FIG. 4) and the second diameter d2 of the second expansion hole 184 are equal (ie, they have the same diameter). The transition channel 186 has a diameter dt. The diameter dt of the transition channel 186 remains the same or constant over the substantially axial length of the transition tube 180. For this embodiment, the diameter dt of the transition channel 186 is at least three and a half (3.5 times) larger than the second diameter d2 of the second expansion hole 184. As further shown, the second conical frustum 188 defined by the transition tube 180 transitions the transition channel 186 to the second expansion hole 184. In addition, for this embodiment, the second conical frustum 188 transitions the transition channel 186 to the second expansion hole 184 at an angle θ2 of about sixty degrees (60 °) with respect to the axial direction a. Preferably, the angle θ2 is at least 45 degrees (45 °) with respect to the axial direction a. The second conical frustum 188 collects the aerosol flow s into the second expansion hole 184 and prevents the stress from rising. The second conical frustum 188 and the second expansion hole 184 form a converging throat of the transition tube 180.

When the aerosol stream s flows through the first expansion hole 134 and enters the first chamber 112 as shown in FIG. 4, the aerosol stream s undergoes expansion through the first expansion hole 134, and the aerosol stream s fills the first chamber 112 therein. The volume expands in the middle time, and therefore, the pressure and temperature of the aerosol flow s in the first chamber 112 decrease. The aerosol flow s may undergo an isentropic expansion through the first expansion hole 134. In addition, when the aerosol flow s expands into the first chamber 112 after leaving the first expansion hole 134, the aerosol flow s may exhibit a turbulent flow characteristic. To minimize the effect on the concentration quality of the aerosol stream s, the decompression system 100 advantageously includes a feature that heats the aerosol stream s and stabilizes the flow before the aerosol stream s reaches the second expansion hole 184. For example, as best shown in FIG. 3, the distance d is defined between the first expansion hole 134 and the second expansion hole 184. It is worth noting that this distance is at least ten (10) times larger than the first diameter d1 and the second diameter d2. The distance d provides a sufficient distance for the aerosol flow s to be heated and stabilized before entering the second expansion hole 184. This heating, which may be isostatic, and the stabilization of the aerosol flow s facilitate a constant volume flow rate (or near constant volume flow rate) through the second expansion hole 184 of the pressure reduction system 100.

In addition, to facilitate the streamline capture of the aerosol flow s leaving the first expansion hole 134 through the transition tube 180, the inlet 182 of the transition tube 180 is aligned with the first expansion hole 134 of the inlet port 130, as shown in FIGS. Show. More specifically, the inlet 182 of the transition tube 180 is concentrically aligned with the first expansion hole 134 of the inlet port 130. For this embodiment, the inlet 182 of the transition tube 180 is concentrically aligned with the first expansion hole 134 of the inlet port 130 along the main axis m. By aligning the inlet 182 of the transition tube 180 with the first expansion hole 134 of the inlet port 130, the particle concentration of the aerosol flow s is better maintained, especially when an overflow pressure valve 150 is moved to the open position to reduce During the pressure p2 in the first chamber 112.

As further shown in FIG. 5, the transition tube 180 extends between the upstream end 190 and the downstream end 192, for example, in the axial direction a, and extends substantially along the main axis m. The upstream end 190 of the transition tube 180 is positioned within the first chamber 112 and the downstream end 192 is positioned within the second chamber 114. The transition tube 180 includes a body 194 and a head 196. The body 194 includes a stepped portion 198 and a conical frustum portion 200. The head 196 of the transition tube 180 is positioned at the downstream end 192 of the transition tube 180 and is placed against the first cylinder 116 (more specifically, the flange 120 of the first cylinder 116). The conical frustum portion 200 extends from the upstream end 190 to the stepped portion 198. The stepped portion 198 is positioned within a transition opening 126 defined by the housing 110 between the first and second chambers 112 and 114. Moreover, for this embodiment, the transition tube 180 is formed of a conductive material, such as a metal material. In some embodiments, only the body 194 needs to be formed of a conductive material.

It is worth noting that the transition tube 180 tapers toward the inlet 182 of the transition tube 180 in the axial direction a. More specifically, the conical frustoconical portion 200 of the transition pipe 180 is tapered from the position where it is connected to the stepped portion 198 toward the upstream end 190 of the transition pipe 180 in the axial direction a. As best shown in FIGS. 6 and 7, the outer diameter of the stepped portion 198 of the body 194 is larger than the outer diameter of the transition tube 180 at its upstream end 190. More specifically, the stepped portion 198 defines a basic diameter db, which is the outer diameter of the transition tube 180 at the stepped portion 198. The conical frustoconical portion 200 defines an upstream diameter du, for example, at the upstream end 190 of the transition tube 180. The upstream diameter du is the outer diameter of the conical frustum portion 200. For this embodiment, the basic diameter db of the stepped portion 198 is at least three (3) times larger than the upstream diameter du.

As shown in FIG. 5, the tapered geometry of the transition tube 180 facilitates heat transfer with the aerosol flow s flowing through the transition tube 180. That is, when the aerosol flow s accelerates through the transition tube 180 (thus cooling the aerosol flow s) before flowing through the second expansion hole 184, the geometry of the transition tube 180 causes the transition tube 180 to exchange heat with the aerosol flow s To counteract the cooling of the aerosol stream s due to its acceleration. More specifically, heat is supplied to the housing 110 via a heating jacket 162, for example. The conductive material of the housing 110 facilitates conductive heat exchange from the outer surface of the housing 110 to the flange 120. The interface between the conductive annular outer surface of the stepped portion 198 and the conductive flange 120 of the housing 110 heats the transition tube 180. The transition tube 180 is heated such that its heat distribution heats the aerosol flow s as it flows through the transition channel 186 defined by the transition tube 180. Heating the aerosol stream s flowing through the transition channel 186 facilitates the expansion of the aerosol through the second expansion hole 184. The expansion through the second expansion hole 184 may be an isentropic expansion.

As further depicted in FIG. 3, the reduced-pressure system 100 includes a sample outlet port 210 that defines a sample outlet 212 of the second chamber 114. As shown, the sample outlet port 210 is misaligned with the second expansion hole 184 along the main axis m. However, in some embodiments, the sample outlet port 210 may be aligned with the second expansion hole 184 along the main axis m. During operation of the reduced-pressure system 100, a portion of the aerosol stream s (denoted as sample stream ss) having a low pressure p3 flows through the sample outlet 212. A particle measurement device 230 located downstream of the sample outlet 212 is fluidly connected to the second chamber 114, for example, via a sample conduit 214, and receives a sample stream ss. Upon receiving the sample stream ss, the particle measurement device 230 is configured to measure various parameters of non-volatile particulate matter within the sample stream ss, including, for example, particle mass, number, size distribution, and the like. Other parameters can also be measured.

In some embodiments, as shown in FIG. 3, the pressure reduction system 100 defines a vertical direction v, such as in a radial direction r. In such an embodiment, the particle measurement device 230 is positioned above the pressure reduction system 100 in the vertical direction v. In this way, particle loss is minimized and water (for example from condensation) is prevented from flowing to the particle measurement device 230, which may provide more accurate particle measurement.

The decompression system 100 also includes a main outlet port 220 that defines a main outlet 222 of the second chamber 114. During operation of the decompression system 100, a portion of the aerosol flow s in the second chamber 114 that does not flow through the sample outlet 212 exits the decompression system 100 through the main outlet 222 and passes through the main conduit 224 to the surrounding environment. Therefore, the second chamber 114 defines two (2) outlets, a sample outlet 212 and a main outlet 222.

An exemplary manner will now be provided in which the decompression system 100 reduces the pressure of the high-pressure aerosol with minimal impact on the concentration of non-volatile particulate matter in the aerosol stream used for sampling purposes. Referring to FIG. 3, an aerosol stream s having a high pressure p3 is directed from a high-pressure environment 122 (eg, a burner assembly of a gas turbine engine) to the pressure reduction system 100 via an inlet conduit 124. The high-pressure aerosol stream s consists of non-volatile particulate matter, such as carbon black (soot), dust, metal and ceramic particles. The aerosol stream s enters the decompression system 100 through the inlet port 130 and undergoes a first pressure drop from a high pressure to a medium pressure after passing through the first expansion hole 134. In particular, when the aerosol stream s flows through the first expansion hole 134 defined by the downstream end of the inlet port 130, the aerosol stream s expands into the first chamber 112 through the first expansion hole 134. That is, the aerosol flow s is compressed and accelerated by the first expansion hole 134, so that the aerosol flow s rapidly expands when the aerosol flow s enters the first chamber 112. The expansion of the gas aerosol stream s through the first expansion hole 134 and into the first chamber 112 may be adiabatic because the high speed and short residence time of the aerosol stream s through the first expansion hole 134 prevents, for example, heat from the inlet port 130 exchange. In addition, the expansion can also be isentropic or near isentropic. After expanding through the first expansion hole 134 and entering the first chamber 112, the pressure of the aerosol flow s decreases from a high pressure p1 to a medium pressure p2. Therefore, the pressure of the aerosol flow s downstream of the first expansion hole 134 and upstream of the second expansion hole 184 is medium pressure p2. Due to the first pressure drop, the temperature of the aerosol stream s also decreases. As mentioned earlier, the intermediate pressure p2 can be controlled to a set pressure, for example, the pressure is released through one or more relief pressure valves 150.

After entering the first chamber 112 after being expanded through the first expansion hole 134, a portion of the aerosol stream s enters the inlet 182 of the transition tube 180. The aerosol flow s flows downstream through the transition channel 186, and when this occurs, the transition tube 180 stabilizes the flow and heats the aerosol flow s within the transition channel 186. The heating jacket 162 of the heating assembly 160 exchanges heat with the casing 110, which in turn exchanges heat with the transition tube 180. The heated transition tube 180 in turn heats the aerosol flow s. Heating the aerosol flow s prevents condensation from forming in the transition channel 186 or the second expansion hole 184, which may adversely affect the concentration of non-volatile particles and / or disrupt the volume flow of the aerosol flow s through the second expansion hole 184.

At the downstream end of the transition tube 180, the heated aerosol flow s with intermediate pressure p2 experiences a second pressure drop. Specifically, the aerosol flow s is expanded through the second expansion hole 184 and enters the second chamber 114. That is, the aerosol flow s is compressed and accelerated by the second expansion hole 184, so that when the aerosol flow s enters the second chamber 114, the aerosol flow s is rapidly expanded. The expansion of the aerosol stream s reduces the pressure from the medium pressure p2 to the low pressure p3, which can be, for example, the ambient pressure. The aerosol stream s having a low pressure p3 is then directed through the sample outlet 212 to a particulate matter measuring device 230 for measuring particles of the sample stream ss of the aerosol stream s. The overcurrent in the second chamber 114 flows through the main outlet 222.

The pressure drop of the aerosol stream s without significant changes in the aerosol characteristics is achieved at least in part by passing a constant or near constant volume flow rate through the first and second expansion holes 134, 184, through the first expansion hole 134 expands and enters the first chamber 112, stabilizes and heats in the transition tube 180, and the aerosol flow s expands through the second expansion hole 184 of the transition tube 180 and enters the second chamber 114.

FIG. 8 provides a flow diagram of an exemplary method (300) for reducing the pressure of an aerosol stream composed of non-volatile particles from high pressure to low pressure without affecting or minimally affecting the concentration of non-volatile particulate matter of the aerosol flow. Illustration. For example, the pressure reduction system 100 described herein can be used to reduce the pressure of a high pressure aerosol flow. For example, the aerosol flow may be the exhaust flow of a gas turbine engine. For the context, reference numbers will be used below to describe the decompression system 100 and its various features.

At (302), method (300) includes expanding the aerosol flow through a first expansion hole into a first chamber defined by the housing to reduce the aerosol flow from high pressure to medium pressure. For example, a high-pressure aerosol stream, such as an exhaust stream from a combustor assembly, may be directed through the first expansion hole 134 of the inlet port 130 of the pressure reduction system 100. Upstream of the first expansion hole 134, the pressure of the aerosol flow has a high pressure p1. For example, the high pressure may be a pressure level between about three bar (3 bar) and about seventy bar (70 bar). When the high-pressure aerosol flow is directed through the first expansion hole 134, the aerosol flow expands and flows into the first chamber 112 defined by the housing 110. The expansion of the aerosol flow reduces the pressure of the aerosol flow from high pressure p1 to intermediate pressure p2. The intermediate pressure p2 is the pressure between the high pressure p1 and the low pressure p3.

At (304), method (300) includes expanding the aerosol flow through a second expansion hole defined by the transition tube into a second chamber defined by the housing to reduce the aerosol flow from medium pressure to low pressure, where the transition tube Fully enclosed in the case. For example, the aerosol flow s in the first chamber 112 having an intermediate pressure p2 after expansion through the first expansion hole 134 at (302) may be directed through the second expansion hole 184 defined by the transition tube 180 of the pressure reduction system 100 . When an aerosol flow s having a medium pressure p2 is directed through the second expansion hole 184, the aerosol flow s expands into the second chamber 114 defined by the housing 110. The expansion of the aerosol stream s through the second expansion hole 184 and into the second chamber 114 reduces the pressure of the aerosol stream s from the intermediate pressure p2 to the low pressure p3. The low pressure p3 may be ambient pressure, such as one atmosphere (1 atm).

In some embodiments, the method (300) includes obtaining a sample stream of the aerosol stream at a low pressure from the second chamber. In this way, a sample stream ss of a representative concentration of non-volatile particles in the aerosol stream at high pressure can be measured by one or more particle measurement devices 230. For example, a portion of the aerosol stream s may flow through the sample outlet 212 of the second chamber 114 and downstream to the particle measurement device 230. Since the pressure of the high-pressure aerosol is reduced to low pressure p3, the quality and properties of the non-volatile particles of the aerosol stream have the least impact. The sample stream ss includes a representative concentration of non-volatile particles found in the high-pressure aerosol stream. The one or more particle measuring devices 230 can accurately measure various parameters of the non-volatile particles.

Further, in some embodiments, the method (300) includes heating the housing. When the casing is heated, the casing exchanges heat with the transition tube, which in turn exchanges heat with the aerosol flow flowing through the transition channel defined by the transition tube upstream of the second expansion hole. In some embodiments, the method (300) includes heating the housing with a heating jacket, or more generally, the method (300) includes heating the housing with a heating assembly.

For example, the housing may be heated using the heating assembly 160 of FIG. 1. More specifically, the case 110 may be heated with the heating jacket 162 as shown in FIG. 1 wrapped around the case 110. The heating jacket 162 may be controlled by one or more controllers 170 to maintain a specific temperature or increase or decrease the temperature of the heating jacket 162 as needed. As described above, when the heating jacket 162 heats the housing 110 (which is preferably formed of a conductive material), the housing 110 exchanges heat with the transition tube 180, which in turn exchanges with the aerosol flow flowing through the transition channel 186 of the transition tube 180. Heat. Therefore, the aerosol flow is heated upstream of the second expansion hole 184. The heating assembly 160 is used to heat the casing 110 to prevent condensation from blocking the expansion holes 134, 184, and in particular to prevent condensation from being formed in the transition channel 186 upstream of the second expansion hole 184. In addition, heating the aerosol flow within the transition channel 186 helps maintain a more consistent volume flow rate through the transition channel 186.

In some embodiments, the first expansion hole is aligned with an inlet defined by a transition tube. By aligning the inlet 182 of the transition tube 180 with the first expansion hole 134 of the inlet port 130, as described above, the particle concentration of the aerosol flow s can be better maintained.

In addition, in some embodiments, the pressure reduction system 100 includes an overflow pressure valve 150 fluidly connected to the first chamber 112. The decompression system 100 further includes a pressure sensing device 140 configured to sense the pressure of the aerosol flow in the first chamber 112. In such an embodiment, the method (300) includes receiving, by the controller, one or more signals from the pressure sensing device indicating the pressure of the aerosol flow in the first chamber. The controller may be one or more controllers 170. The method (300) further includes determining whether the pressure of the aerosol flow in the first chamber is within a predetermined range of the set pressure. The method (300) further includes adjusting a valve position of the overflow pressure valve based at least in part on whether the pressure of the aerosol flow in the first chamber is within a predetermined range of the set pressure.

In some embodiments, the set pressure in the first chamber is set based at least in part on the following equation:

Among them, pset is the set pressure in the first chamber 112, p1 is the pressure of the aerosol flow upstream of the first expansion hole 134, and p3 is the pressure of the aerosol flow downstream of the second expansion hole 184. For example, the controller 170 of the pressure reduction system 100 may control the valve positions of the one or more relief pressure valves 150 to open or close to achieve the desired pressure p3 in the second chamber 114. By setting the set temperature according to Equation 1, the temperature decreases due to the expansion of the aerosol flow through the first expansion hole 134 into the first chamber 112, and the expansion of the aerosol flow through the second expansion hole 184 into the second chamber 114 is minimal This, in turn, facilitates a more consistent volumetric flow rate of the aerosol flow as it flows through the decompression system 100.

In some embodiments, the set pressure is dynamically set based at least in part on the pressure of the aerosol flow upstream of the first expansion hole. That is, the set pressure within the first chamber 112 may be dynamically changed based at least in part on a pressure reading of the incoming high-pressure aerosol flow. Advantageously, the ambient pressure of the aerosol flow in the second chamber 114 is set by dynamically setting the set pressure of the pressure of the aerosol flow in the first chamber 112 and removing the excess pressure therefrom, for example, by opening the overflow pressure valve 150. This can be achieved consistently, even with pressure fluctuations of the incoming aerosol flow. This may be particularly advantageous in obtaining a sample stream from an exhaust aerosol stream from a combustor assembly of a gas turbine engine in transient operation. Therefore, particulate matter emissions can be studied for transient operation of a gas turbine engine mounted to an aircraft. For example, a sample can be obtained that simulates emissions from a gas turbine engine during takeoff, evasive manoeuvres, climbs, or other power change maneuvers.

Although specific features of various embodiments may be shown in some drawings and not shown in others, this is for convenience only. In accordance with the principles of the present disclosure, any feature of any other drawing may be referenced and / or claimed in combination with any feature of any other drawing.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. These other examples are intended to fall within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

The various features, aspects, and advantages of the present invention can also be embodied in various technical solutions described in the following items, and these solutions can be combined in any combination:

A decompression system, comprising:

A housing defining a first chamber and a second chamber positioned downstream of the first chamber;

An inlet port fluidly connecting the high-pressure environment and the first chamber, the inlet port defining a first expansion hole through which an aerosol flow composed of non-volatile particles passes from the high-pressure environment Conveyed to the first chamber, wherein the aerosol flow has a first pressure drop from high to medium pressure after passing through the first expansion hole;

A transition tube fluidly connecting the first chamber and the second chamber, the transition tube defining an inlet and a second expansion hole through which the aerosol flow passes from the first expansion hole A chamber to the second chamber, wherein the aerosol flow has a second pressure drop from the intermediate pressure to the low pressure after passing through the second expansion hole; and

A sample outlet port defining a sample outlet of the second chamber, wherein a portion of the aerosol flow having the low pressure is configured to flow through the sample outlet.

2. The decompression system according to item 1, wherein the decompression system defines a main axis, and wherein the inlet of the transition pipe is along the main axis and the location of the inlet port. The first expansion holes are aligned concentrically.

3. The decompression system according to item 1, wherein the first expansion hole has a first diameter, the second expansion hole has a second diameter, and wherein the first diameter is equal to the Second diameter.

4. The decompression system according to item 3, wherein a distance is defined between the first expansion hole and the second expansion hole, and wherein the distance is greater than the first diameter and the The second diameter is at least ten (10) times larger.

5. The decompression system according to item 1, wherein the decompression system defines an axial direction, and wherein the transition pipe includes the transition pipe facing the transition pipe along the axial direction. The entrance tapers the body.

6. The decompression system according to item 5, wherein the body has a stepped portion positioned between the first and second chambers and defined by the housing. Inside the transition opening, and wherein the stepped portion defines a basic diameter, and wherein the body of the transition tube tapers from the stepped portion to the inlet of the transition tube along the axial direction.

7. The decompression system according to item 6, wherein the body has an upstream diameter, and wherein the diameter of the stepped portion of the body is at least three larger than the upstream diameter of the body ( 3 times.

8. The decompression system according to item 1, wherein the transition pipe is completely contained in the housing.

9. The decompression system according to item 1, further comprising:

A heating component for heating the casing.

10. The decompression system according to item 9, wherein the housing is formed of a conductive material, the transition tube is formed of a conductive material, and wherein the heating jacket is selectively at a predetermined set temperature The casing is heated.

11. The decompression system according to item 1, further comprising:

An overflow pressure valve fluidly connected to the first chamber for selectively adjusting the pressure of the aerosol flow in the first chamber;

A pressure sensing device fluidly connected to the first chamber for measuring the pressure of the aerosol flow in the first chamber;

A controller communicatively coupled to the relief pressure valve and the pressure sensing device, the controller being configured to:

Receiving one or more signals from the pressure sensing device indicating the pressure of the aerosol flow in the first chamber;

Determining whether the pressure of the aerosol flow in the first chamber is within a predetermined range of a set pressure; and

Controlling the relief pressure valve based at least in part on whether the pressure of the aerosol flow in the first chamber is within the predetermined range of the set pressure to adjust the pressure of the relief pressure valve Valve position.

12. The decompression system according to item 1, wherein the sample outlet is fluidly connected to a particle measurement device configured to measure the non-volatile particles of the aerosol flow And wherein the decompression system defines a vertical direction, and the particle measurement device is positioned above the decompression system along the vertical direction.

13. The decompression system according to item 1, wherein the transition tube defines a transition channel, the transition channel connecting the inlet of the transition tube and the second expansion of the transition tube Holes are fluidly connected, and wherein the transition tube has a diameter and the second expansion hole has a second diameter, and wherein the diameter of the transition channel is at least larger than the second diameter of the second expansion hole Three and a half times (3.5 times).

14. A method for reducing the pressure of an aerosol stream composed of non-volatile particles from a high pressure to a low pressure, characterized in that the method comprises:

Expanding the aerosol flow through a first expansion hole into a first chamber defined by a housing to reduce the aerosol flow from the high pressure to a medium pressure; and

The aerosol flow is expanded into a second chamber defined by the housing through a second expansion hole defined by a transition tube to reduce the aerosol flow from the intermediate pressure to the low pressure, wherein The transition tube is completely contained within the housing.

15. The method according to item 14, further comprising:

A sample stream of the aerosol stream at the low pressure is obtained from the second chamber, wherein the sample stream includes a representative of the non-volatile particles in the aerosol stream at the high pressure concentration.

16. The method according to item 14, further comprising:

Heating the casing, wherein when the casing is heated, the casing exchanges heat with the transition tube, and the transition tube exchanges heat with the aerosol flow flowing through the transition channel, and the transition channel is at An upstream of the second expansion hole is defined by the transition pipe.

17. The method of clause 14, wherein an overflow pressure valve is fluidly connected to the first chamber, and a pressure sensing device is configured to sense the aerosol flow in the first chamber The pressure, and wherein the method further comprises:

Receiving one or more signals from the pressure sensing device indicating the pressure of the aerosol flow in the first chamber through a controller;

Determining whether the pressure of the aerosol flow in the first chamber is within a predetermined range of a set pressure; and

A valve position of the relief pressure valve is adjusted based at least in part on whether the pressure of the aerosol flow in the first chamber is within the predetermined range of the set pressure.

18. The method of clause 17, wherein it is based at least in part on an equation: To set the set pressure in the first chamber, where pset is the set pressure in the first chamber, and p1 is the pressure of the aerosol flow upstream of the first expansion hole, p3 is the pressure of the aerosol flow downstream of the second expansion hole.

19. The method of clause 18, wherein the set pressure is dynamically set based at least in part on the pressure of the aerosol flow upstream of the first expansion hole.

20. A decompression system, comprising:

A housing formed at least partially of a conductive material and defining a first chamber and a second chamber, the second chamber positioned downstream of the first chamber;

An inlet port fluidly connecting the high-pressure environment and the first chamber, the inlet port defining a first expansion hole through which an aerosol flow composed of non-volatile particles passes from the high-pressure environment Conveyed to the first chamber, wherein the aerosol flow has a first pressure drop from high to medium pressure after passing through the first expansion hole;

An overflow pressure valve fluidly connected to the first chamber for selectively adjusting the pressure of the aerosol flow in the first chamber;

A transition tube formed of a conductive material and fluidly connecting the first and second chambers and mounted to the housing, the transition tube defining an inlet and a second expansion hole, the aerosol flow Conveyed from the first chamber to the second chamber through the second expansion hole, wherein the aerosol flow has a second pressure drop from the intermediate pressure to the low pressure after passing through the second expansion hole;

A heating assembly for providing heat to the housing; and

A sample outlet port defining a sample outlet of the second chamber, wherein a portion of the aerosol flow having the low pressure is configured to flow through the sample outlet.

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