A waste heat recovery device, system and method for an aeroengine indoor test bed

Abstract

This invention discloses a waste heat recovery device, system, and method for an indoor test stand for aero-engines. The waste heat recovery device includes: multiple annular cold water pipes spaced axially along the outer wall of an ejector tube; and multiple I-shaped heat pipes arranged circumferentially within the annular cold water pipes. Each I-shaped heat pipe includes an evaporation end (arranged as an arc segment), a condensation end, and an adiabatic section. The evaporation end located on the inner side is in contact with the outer wall of the ejector tube, and the condensation end located on the outer side is in contact with the inner wall of the corresponding annular cold water pipe. The I-shaped heat pipes facilitate heat exchange between the ejector tube and the annular cold water pipes to recover the heat energy from the exhaust gas in the ejector tube. The technical solution provided by this invention solves the waste heat recovery problem of indoor test stands for aero-engines, improves the energy utilization rate of indoor test stands for aero-engines, and has high practicality and advancement, and can be widely applied to indoor test stands for aero-engines.

Description

Technical Field

[0001] This application relates to, but is not limited to, the fields of indoor test technology for aero-engines and the field of heat recovery technology, and particularly to a waste heat recovery device, system and method for an indoor test stand for aero-engines. Background Technology

[0002] Waste heat is defined as energy that is not fully utilized or used in human production and daily life. With the increasing awareness of energy conservation and emission reduction, waste heat recovery and utilization has become a research hotspot in various industries. Waste heat generated in industries such as steel, petroleum, and chemicals has been extensively studied and utilized in practice. Currently, common waste heat recovery methods mainly include heat exchangers and heat pumps. A heat exchanger is a device that transfers heat from a high-temperature fluid to a low-temperature fluid to recover thermal energy. A heat pump, on the other hand, consumes some mechanical work and uses a reverse Carnot cycle to transfer heat from a low-temperature heat source to a high-temperature heat source.

[0003] Aero-engine testing is a crucial step in verifying engine performance and safety, generating significant amounts of waste heat during the process. However, due to the complexity of aero-engine testing conditions, exhaust flow and temperature vary considerably under different testing scenarios; furthermore, indoor test benches impose stringent requirements on exhaust aerodynamic drag and noise control. Currently, waste heat recovery is not widely applied in indoor aero-engine test benches, and feasible technical solutions are lacking. Therefore, it is necessary to develop a suitable and efficient waste heat recovery method tailored to the characteristics of indoor aero-engine test benches to improve the energy utilization rate of the test benches. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems. The embodiments of this invention provide a waste heat recovery device, system and method for an indoor test stand for aero-engines, so as to solve the waste heat recovery problem of the indoor test stand for aero-engines and improve the energy utilization rate of the indoor test stand for aero-engines. It has high practicality and advanced features and can be widely used in indoor test stands for aero-engines.

[0005] The technical solution of the present invention: The present invention provides a waste heat recovery device for an indoor test stand for an aero-engine. The indoor test stand for the aero-engine is equipped with an exhaust system. The exhaust system uses an ejector tube 3 located in the ejector chamber 2 to eject the high-temperature, high-speed exhaust gas from the engine tail nozzle to the ambient temperature gas in the test chamber 1. After the exhaust gas is mixed with the ejector, its temperature and velocity decrease, and it is discharged into the exhaust tower 4. The waste heat recovery device includes:

[0006] Multiple annular cold water pipes 9 are arranged at intervals along the axial direction on the outer wall of the ejector tube 3. In the annular plane formed by each annular cold water pipe 9 and the ejector tube 3, multiple I-shaped heat pipes are arranged circumferentially. The annular cold water pipes 9 are fixedly supported on the outer wall of the ejector tube 3 by the multiple I-shaped heat pipes arranged circumferentially.

[0007] Each of the I-shaped heat pipes includes an evaporation end 6 and a condensation end 8, which are configured as arc segments, and an adiabatic section 7 for connecting the evaporation end 6 and the condensation end 8. The closed connecting cavity formed by the evaporation end 6, the adiabatic section 7 and the condensation end 8 is filled with a liquid working fluid located at the evaporation end 6.

[0008] After each of the I-shaped heat pipes is installed, the inner evaporation end 6 is attached to the outer wall of the ejector tube 3, and the outer condensation end 8 is attached to the inner wall of the annular cold water pipe 9 at the corresponding installation position. This is used to evaporate the liquid working fluid in the evaporation end 6 into gas through the heat energy in the ejector tube 3. After the gas passes through the insulation section 7 to the condensation end 8, the gas in the condensation end 8 is liquefied by the cold water flowing in the annular cold water pipe 9 and then returns to the evaporation end 6, thereby forming a heat exchange with the annular cold water pipe 9 to recover the heat energy of the exhaust gas in the ejector tube 3.

[0009] Optionally, in the waste heat recovery device of the aircraft engine indoor test stand as described above,

[0010] In the I-shaped heat pipe, the inner wall surface of the evaporation end 6 is set as an arc-shaped surface along the installation circumference, which fits against the outer wall surface of the ejector tube 3.

[0011] The outer wall of the condenser end 8 is recessed inward along the installation circumference to form a semi-circular groove, so as to embed the inner ring wall of the annular cold water pipe 9 into the semi-circular groove.

[0012] Optionally, in the waste heat recovery device of the aircraft engine indoor test stand as described above,

[0013] The multiple annular cold water pipes 9 are arranged in the axial direction of the ejector tube 3 according to the temperature distribution of the exhaust gas inside the ejector tube 3.

[0014] The annular cold water pipes 9 arranged at intervals along the axial direction of the ejector tube 3 have the same annular diameter, or the annular diameters of the multiple annular cold water pipes 9 are different.

[0015] Optionally, in the waste heat recovery device of the aircraft engine indoor test stand as described above,

[0016] The arrangement of the I-shaped heat pipes on the outer wall of the ejector tube 3 is determined according to the temperature distribution of the exhaust gas inside the ejector tube 3. The arrangement of the I-shaped heat pipes includes the number of pipes and their positions.

[0017] Optionally, in the waste heat recovery device of the aircraft engine indoor test stand as described above,

[0018] By adjusting the number and location of the I-shaped heat pipes, as well as the length of the insulating section 7 in the I-shaped heat pipes, the waste heat recovery device can be applied to the heat recovery of ejector tubes 3 with different exhaust temperature distributions.

[0019] This invention also provides a waste heat recovery system for an indoor test stand for an aero-engine, comprising: a waste heat recovery device as described in any of the above claims, and at least one set of heat circulation pipelines;

[0020] The hot circulation pipeline includes: an inlet pipe connected to the front end of the annular cold water pipe 9, and an outlet pipe connected to the rear end of the annular cold water pipe 9; the inlet pipe is sequentially connected to an inlet switch valve 10, an inlet regulating valve 11, a filter 12, a circulation pump 13, a flow meter, and a temperature sensor; the outlet pipe is sequentially connected to an outlet switch valve 14, an outlet regulating valve 17, and an outlet switch valve 18; and a return branch pipe is provided at the rear end of the outlet switch valve 14, the other end of which is connected to the inlet pipe between the inlet regulating valve 11 and the filter 12; and a branch regulating valve 15 and a branch switch valve 16 are sequentially connected to the return branch pipe.

[0021] The heat circulation pipeline is used to provide low-temperature water through the inlet pipeline. After being pressurized by the circulation pump 13, the low-temperature water enters the annular cold water pipeline 9. After heat exchange between the annular cold water pipeline 9 and the I-shaped heat pipe, high-temperature water flows out. Part of the high-temperature water flows out through the outlet pipeline for recycling. The other part of the high-temperature water is mixed with the low-temperature water in the inlet pipeline through the return branch pipeline to form a circulation loop.

[0022] Optionally, in the waste heat recovery system of the aircraft engine indoor test stand described above, the test runs conducted on the aircraft engine indoor test stand have multiple test conditions.

[0023] The waste heat recovery system adjusts the inlet cold water temperature of the annular cold water pipe 9 by adjusting the opening of the inlet regulating valve 11 and the branch regulating valve 15, thereby meeting the heat energy recovery requirements of the outer wall temperature of the ejector tube 3 under different test conditions.

[0024] Optionally, in the waste heat recovery system of the aircraft engine indoor test stand as described above,

[0025] The multiple annular cold water pipes 9 in the waste heat recovery device are connected in parallel to a set of heat circulation pipes; or,

[0026] Each of the annular cold water pipes 9 in the waste heat recovery device is equipped with a set of heat circulation pipelines.

[0027] Optionally, the waste heat recovery system of the aircraft engine indoor test stand as described above also includes: a storage tank;

[0028] A storage tank is installed between the rear end of the outlet switch valve 18 of the water outlet pipeline and the load to store high-temperature water from the water outlet pipeline, so as to ensure stable operation of the load.

[0029] This invention also provides a waste heat recovery method for an indoor test stand for aero-engines, which employs a waste heat recovery system for the indoor test stand for aero-engines as described in any of the preceding embodiments to perform waste heat recovery on the indoor test stand for aero-engines. The waste heat recovery method includes:

[0030] Step 1: Based on the temperature distribution of the exhaust gas inside the ejector tube 3 in the indoor test stand of the aero-engine, determine the number of annular cooling water pipes 9 and their axial placement in the ejector tube 3.

[0031] Step 2: Based on the CFD multiphase flow simulation of the I-shaped heat pipe, by comparing the I-shaped heat pipes with different lengths of adiabatic section 7 and comparing the heat transfer efficiency of different I-shaped heat pipes in terms of layout, including the number of layouts and the layout position, the length of the adiabatic section 7 and the layout of the I-shaped heat pipes used for waste heat recovery on the current test bench are determined.

[0032] Step 3: After connecting the hot circulation pipeline to each annular cold water pipe 9, perform waste heat recovery on the indoor test stand of the aero-engine under various test conditions.

[0033] In the process of waste heat recovery under different test conditions, the inlet cold water temperature of the annular cold water pipeline 9 is adjusted by adjusting the opening of the inlet regulating valve 11 and the branch regulating valve 15.

[0034] The beneficial effects of the present invention are as follows: The waste heat recovery device, system and method of the indoor test stand of the aero-engine provided by the embodiments of the present invention are formed by reasonably arranging multiple I-shaped heat pipes and multiple annular cold water pipes 9 on the outer wall of the ejector tube 3 to form a waste heat recovery device, and by setting up a heat circulation pipeline for the waste heat recovery device to form a waste heat recovery system, thereby implementing the waste heat recovery method by using the waste heat recovery system. In the aforementioned waste heat recovery technical solution, on the one hand, by structurally modifying the evaporator end 6 and condenser end 8 of a conventional straight heat pipe, an I-shaped heat pipe is formed that can be adapted to the outer wall surface of the ejector tube 3 and the outer wall surface of multiple annular cold water pipes 9, thereby implementing heat exchange between the ejector tube 3 and the annular cold water pipes 9; on the other hand, CFD aerodynamic simulation based on a test bench is used to obtain the temperature distribution of the exhaust gas inside the ejector tube 3, thereby correspondingly arranging the I-shaped heat pipes and annular cold water pipes 9 in the area with higher exhaust gas temperature on the outer wall surface of the ejector tube 3; in addition, CFD multiphase flow simulation based on the I-shaped heat pipe is used to determine the heat transfer efficiency under different lengths of adiabatic section 7 and by comparing different arrangement forms of I-shaped heat pipes (including the number and location of arrangement), thus confirming the heat transfer efficiency. The optimal structure and layout of the I-shaped heat pipes were determined. Furthermore, considering the significant variations in exhaust flow and temperature on the test bench under various test conditions during aero-engine testing, resulting in substantial temperature variations on the outer wall of the ejector tube 3 and consequently significant variations in heat exchange or waste heat recovery, a return branch pipe was installed on the outlet water pipe. The opening of the branch regulating valve 15 in the return branch pipe and the inlet regulating valve 11 in the inlet water pipe were used to control the inlet cold water temperature, thereby adjusting the heat exchange and improving the adjustment range, control accuracy, stability, and response speed of the heat exchange. Additionally, a storage tank was installed at the front end of the load to store high-temperature water from the outlet water pipe, ensuring stable load operation.

[0035] The technical solution provided by this invention, through adaptability modifications to conventional straight heat pipes, optimizes the shape, structure, and layout of I-shaped heat pipes, and provides a control scheme for adjusting the inlet chilled water temperature and an online lookup table control strategy. This solves the waste heat recovery problem of indoor test benches for aero-engines, achieving efficient recovery of waste heat and improving the energy utilization rate of the test bench. It possesses high practicality and advanced features and can be widely applied to indoor test benches for aero-engines. Furthermore, this waste heat recovery scheme has advantages such as strong adaptability, high stability, and high control precision, and can meet the waste heat recovery requirements under different test conditions. Attached Figure Description

[0036] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0037] Figure 1 A schematic diagram of the exhaust system of an indoor test bench for an aircraft engine;

[0038] Figure 2 A schematic diagram of the structural relationship of a waste heat recovery device installed on an ejector tube in an indoor test stand for an aero-engine, provided as an embodiment of the present invention;

[0039] Figure 3 for Figure 2 A schematic diagram of the structural relationship of the waste heat recovery device provided in the embodiment of the present invention, installed in the indoor test stand of an aero-engine.

[0040] Figure 4 for Figure 2 A schematic diagram of the I-shaped heat pipe structure in the waste heat recovery device provided in the embodiment shown;

[0041] Figure 5 This is a schematic diagram of the waste heat recovery system of an indoor test stand for an aero-engine, provided as an embodiment of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0043] As explained in the background section, waste heat recovery is not yet widely used in indoor test rigs for aero-engines, and feasible technical solutions are lacking. Aero-engine testing is characterized by complex test conditions and significant differences in exhaust flow and temperature under various test conditions. Furthermore, indoor test rigs have very high requirements for exhaust aerodynamic drag and noise control. Therefore, considering the characteristics of indoor aero-engine test rigs, developing a waste heat recovery solution for indoor aero-engine test rigs requires addressing the following technical issues:

[0044] 1. Solve the adaptability problem of waste heat recovery equipment for indoor test benches of aero engines;

[0045] 2. Solve the problem of the impact of exhaust flow and temperature changes under various test conditions on the waste heat recovery of the indoor test stand for aero-engines.

[0046] This invention analyzes the characteristics of indoor test benches for aero-engines and addresses the problem of heat loss caused by high-temperature exhaust from the exhaust system of the indoor test bench, which affects the energy utilization rate of the test bench. It develops a highly efficient waste heat recovery scheme applicable to multiple test conditions and applies it to indoor test benches for aero-engines, aiming to improve the energy utilization rate of the test bench and promote the energy-saving process of indoor test benches for aero-engines.

[0047] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0048] The embodiments of this invention aim to achieve waste heat recovery from the indoor test stand of an aero-engine, specifically waste heat recovery from the exhaust system of the test stand. For example... Figure 1 The diagram shown is a structural schematic of an exhaust system for an indoor test bench of an aero-engine. Figure 1 Pilot plant 1 is connected to ejector chamber 2. Exhaust tower 4 is vertically installed and connected to ejector chamber 2. Exhaust tower 4 is equipped with exhaust muffler 5. Ejector chamber 2 is equipped with ejector tube 3, with the inlet of ejector tube 3 located inside pilot plant 1 and the outlet located inside exhaust tower 4. The ejector tube 3 is used to eject the high-temperature, high-speed exhaust gas from the engine tailpipe into the ambient temperature gas inside pilot plant 1. After mixing, the exhaust gas temperature and velocity decrease, and the gas is discharged into exhaust tower 4. Figure 1 The direction of exhaust flow is indicated by dashed arrows.

[0049] right Figure 1 The waste heat recovery of the exhaust system of the test stand shown refers to the recovery of waste heat from the hot gas discharged from the ejector tube 3. Regarding this ejector tube 3, this embodiment of the invention first provides a waste heat recovery device. Figure 2 This is a schematic diagram illustrating the structural relationship of a waste heat recovery device for an indoor test stand of an aero-engine installed on an ejector tube, according to an embodiment of the present invention. Figure 3 for Figure 2 The illustrated embodiment shows a schematic diagram of the structural relationship of the waste heat recovery device installed in the indoor test stand of an aero-engine. (Combined with...) Figure 2 and Figure 3 As shown, the waste heat recovery device provided in this embodiment of the invention includes: multiple annular cold water pipes 9 and multiple I-shaped heat pipes.

[0050] The structure of the waste heat recovery device is as follows: multiple annular cold water pipes 9 are arranged at intervals along the axial direction on the cylindrical outer wall of the ejector tube 3; in addition, multiple I-shaped heat pipes are arranged circumferentially in the annular plane formed by each annular cold water pipe 9 and the ejector tube 3, and the annular cold water pipe 9 is fixedly supported on the outer side of the cylinder wall of the ejector tube 3 by the multiple I-shaped heat pipes arranged circumferentially.

[0051] It should be noted that, as Figure 3 The diagram illustrates that three annular cooling water pipes 9 are spaced apart along the axial direction on the outer wall of the ejector tube 3. Figure 2The illustration only shows a single annular cold water pipe 9 and an ejector tube 3 with one I-shaped heat pipe. In practical applications, multiple I-shaped heat pipes are arranged circumferentially within the annular plane to achieve efficient heat recovery. This embodiment of the invention does not limit the number or location of the annular cold water pipe 9 and the I-shaped heat pipes; the arrangement of each component in the waste heat recovery device is determined based on the actual situation of the ejector tube 3.

[0052] Figure 4 for Figure 2 A schematic diagram of the I-shaped heat pipe structure in the waste heat recovery device provided in the illustrated embodiment. (Combined with...) Figure 2 and Figure 4 As shown, each I-shaped heat pipe includes an evaporating end 6 and a condensing end 8, which are configured as arc segments, and an insulating section 7 for connecting the evaporating end 6 and the condensing end 8. In the structure of the I-shaped heat pipe, the closed connecting cavity formed by the evaporating end 6, the insulating section 7 and the condensing end 8 is filled with a liquid working medium located at the evaporating end 6, which is usually water.

[0053] The waste heat recovery principle of the waste heat recovery device provided in this embodiment of the invention is as follows:

[0054] After the annular cold water pipe 9 and the corresponding I-shaped heat pipe are installed in place, the inner evaporation end 6 of the I-shaped heat pipe is in contact with the outer wall of the ejector tube 3, and the outer condensation end 8 is in contact with the inner wall of the annular cold water pipe 9. Therefore, the heat energy in the ejector tube 3 can evaporate the liquid working fluid in the evaporation end 6 into gas. After the gas passes through the insulation section 7 to the condensation end 8, the cold water flowing in the annular cold water pipe 9 liquefies the gas in the condensation end 8 and returns it to the evaporation end 6. Thus, the I-shaped heat pipe enables heat exchange between the ejector tube 3 and the annular cold water pipe 9, achieving the goal of recovering the heat energy in the ejector tube 3, that is, fulfilling the waste heat recovery requirements of the aircraft engine indoor test stand.

[0055] Reference Figure 2 and Figure 4 As shown, in the I-shaped heat pipe structure of this embodiment, the overall structure of the evaporator end 7 and the condenser end 8 is set as an arc segment, and the arc segment matches the inner and outer rings of the annular plane formed by the annular cold water pipe 9 and the ejector tube 3. The inner wall surface of the evaporator end 7 is set as a smooth arc-shaped surface along the installation circumference, which can fit against the outer wall surface of the ejector tube 3. In addition, the outer wall surface of the condenser end 8 is concave inward along the installation circumference to form a semi-circular groove, which can embed the inner ring wall surface of the annular cold water pipe 9 into the semi-circular groove. This semi-circular groove structure of the condenser end 8, on the one hand, can form a stable and reliable installation structure with the annular cold water pipe 9, and on the other hand, increases the heat exchange area, which is beneficial for heat energy recovery.

[0056] In one implementation of this invention, the temperature distribution of the exhaust gas inside the ejector tube 3 is obtained based on CFD aerodynamic simulation of the test bench, thereby determining the axial arrangement positions of the annular cooling water pipe 9 and the I-shaped heat pipe. Typically, the I-shaped heat pipe and the annular cooling water pipe 9 are arranged in the region with higher exhaust gas temperature inside the ejector tube 3. It should be noted that since multiple I-shaped heat pipes need to be arranged in each annular cooling water pipe 9 and ejector tube 3, the axial arrangement position of the I-shaped heat pipe on the outer wall of the ejector tube 3 is also the axial arrangement position of the annular cooling water pipe 9 in the ejector tube 3.

[0057] In one embodiment of this implementation, the annular cold water pipes 9, which are spaced apart along the axial direction of the ejector tube 3, have the same annular diameter, such as... Figure 3 The three annular cold water pipes 9 shown have the same diameter. In this scheme, if the temperature of the three annular cold water pipes 9 is the same, the same number of I-shaped heat pipes can be laid inside each annular cold water pipe 9. If the temperature of the three annular cold water pipes 9 is different, the number of I-shaped heat pipes laid inside the annular cold water pipe 9 in the high-temperature region can be greater than the number of I-shaped heat pipes laid inside the annular cold water pipe 9 in the low-temperature region.

[0058] In another implementation of this method, the annular diameters of the multiple annular cold water pipes 9 spaced apart along the axial direction of the ejector tube 3 can be different. For example, the annular diameter of the annular cold water pipe 9 in the high-temperature region can be larger than that in the low-temperature region. It should be noted that in implementations with different annular diameters, the length of the insulating section 7 of the I-shaped heat pipes arranged inside the annular cold water pipes 9 with different annular diameters is different, and the specific structure of the I-shaped heat pipes needs to match the annular diameter of the corresponding annular cold water pipe 9.

[0059] In another implementation of the present invention, based on CFD multiphase flow simulation of I-shaped heat pipes, by comparing the heat transfer efficiency of I-shaped heat pipes with different lengths of adiabatic section 7 and different layout forms (including the number and location of the I-shaped heat pipes), the optimal number and location of I-shaped heat pipes, as well as the optimal length of the adiabatic section 7 in the I-shaped heat pipes, can be selected.

[0060] In this implementation, based on CFD multiphase flow simulation of I-shaped heat pipes, the layout parameters of the I-shaped heat pipes, namely the length, number, and location of the adiabatic section 7, can be determined through simulation for different ejector tubes 3. Therefore, by changing the above layout parameters, the waste heat recovery device provided in this embodiment of the invention can be applied to the heat energy recovery of ejector tubes 3 with different exhaust temperature distributions. That is, the waste heat recovery device provided in this embodiment of the invention has universal applicability to indoor test benches for aero-engines with different specific structures and performance.

[0061] In specific implementation of this invention, considering the vibration of the ejector tube 3 during engine testing, the annular cooling water pipe can be made of a flexible metal hose.

[0062] The waste heat recovery device for an indoor test stand for an aero-engine provided in this embodiment of the invention achieves waste heat recovery by rationally arranging multiple I-shaped heat pipes and multiple annular cold water pipes 9 on the outer wall of the ejector tube 3. On one hand, considering that the high-temperature wall of the ejector tube 3 and the low-temperature wall of the annular cold water pipe 9 are both cylindrical or annular surfaces, the evaporation end 6 and condensation end 8 of the conventional straight heat pipe are structurally modified, and cylindrical or annular surfaces adapted to the outer wall of the ejector tube 3 and the annular cold water pipe 9 are designed respectively. On the other hand, in order to increase the heat transfer area, the cross-sectional dimensions of the evaporation end 6 and the condensation end 8 are enlarged, and arc-shaped sections extending on both sides are designed, thus forming an I-shaped heat pipe in the overall structure. On the one hand, based on the CFD aerodynamic simulation of the test bench, the temperature distribution of the exhaust gas inside the ejector tube 3 is obtained, so that I-shaped heat pipes and annular cold water pipes 9 are arranged in the area with higher exhaust gas temperature on the outer wall of the ejector tube 3. Furthermore, based on the CFD multiphase flow simulation of the I-shaped heat pipes, the optimal structure and arrangement of the I-shaped heat pipes are determined by comparing the heat transfer efficiency of I-shaped heat pipes with different lengths of adiabatic sections 7 and different arrangement forms of I-shaped heat pipes (including the number and location of arrangement).

[0063] Based on the waste heat recovery device for an indoor test stand for an aero-engine provided in the above embodiments of the present invention, the present invention also provides a waste heat recovery system for an indoor test stand for an aero-engine. Figure 5 This is a schematic diagram of a waste heat recovery system for an indoor test stand for an aero-engine, provided as an embodiment of the present invention. Figure 5 As shown, the waste heat recovery system includes: a waste heat recovery device as provided in any of the above embodiments, the structure of which can be referred to Figures 2 to 4 And at least one set of heat circulation piping.

[0064] Combination Figure 2 , Figure 3 and Figure 5As shown, the heat circulation pipeline in the waste heat recovery system provided in this embodiment of the invention includes: an inlet pipeline connected to the front end of the annular cold water pipeline 9, and an outlet pipeline connected to the rear end of the annular cold water pipeline 9; the inlet pipeline is sequentially connected to an inlet switch valve 10, an inlet regulating valve 11, a filter 12, a circulation pump 13, a flow meter, and a temperature sensor; the outlet pipeline is sequentially connected to an outlet switch valve 14, an outlet regulating valve 17, and an outlet switch valve 18, and a return branch pipeline is provided at the rear end of the outlet switch valve 14. The other end of the return branch pipeline is connected to the inlet pipeline between the inlet regulating valve 11 and the filter 12, and a branch regulating valve 15 and a branch switch valve 16 are sequentially connected to the return branch pipeline. The inlet switch valve 10, outlet switch valve 14, branch switch valve 16, and outlet switch valve 18 are used to control the on / off state of the corresponding flow paths, and the inlet regulating valve 11, branch regulating valve 15, and outlet regulating valve 17 are used to regulate the flow rate of the corresponding flow paths to control the inlet cold water temperature.

[0065] The working principle of the heat circulation pipeline in this embodiment of the invention is as follows:

[0066] Low-temperature water is supplied through the inlet pipe. After being pressurized by the circulating pump 13, the low-temperature water enters the annular cold water pipe 9. After heat exchange between the annular cold water pipe 9 and the I-shaped heat pipe, high-temperature water flows out. Part of the high-temperature water flows out through the outlet pipe for recycling. The other part of the high-temperature water is mixed with the low-temperature water in the inlet pipe through the return branch pipe to form a circulation loop.

[0067] It should be noted that the test runs conducted on the aircraft engine indoor test bench refer to engine tests, which have multiple test conditions, typically including four: idle, 0.8 rpm, intermediate, and afterburner. For these different test conditions, the exhaust flow rate and temperature of the test bench vary greatly, resulting in significant temperature variations on the outer wall of the ejector tube 3, and consequently, large variations in the amount of heat exchanged or waste heat recovered. Therefore, for different test conditions, it is difficult to achieve a wide range of heat exchange adjustments simply by regulating the flow rate of the annular cooling water pipe 9.

[0068] To address the aforementioned problems, the waste heat recovery system provided in this embodiment of the invention, on the one hand, involves setting a return branch pipe on the outlet pipe of the heat circulation pipeline. The high-temperature water in this return branch pipe can be mixed with the low-temperature water in the inlet pipe to adjust the inlet cold water temperature of the annular cold water pipe 9. Based on the heat circulation pipeline structure of this waste heat recovery system, in addition to the adjustable cold water flow rate of the annular cold water pipe 9, the heat exchange can also be adjusted by controlling the inlet cold water temperature. By adjusting both the cold water flow rate and the cold water temperature, the adjustment range, control accuracy, stability, and response speed of the heat exchange can be improved.

[0069] The waste heat recovery system provided in this embodiment of the invention can adjust the temperature of the cold water in the hot circulation pipeline under various test conditions by adjusting the opening of the inlet regulating valve 11 and the branch regulating valve 15, thereby meeting the heat energy recovery requirements of the outer wall temperature of the ejector tube 3 under different test conditions.

[0070] In practical implementation, the control scheme for the inlet cold water temperature can be an online lookup table method. Based on the real-time temperature of the outer wall of the ejector tube 3, the pre-set mapping table of "ejector tube outer wall temperature - inlet cold water temperature (i.e., the inlet temperature of the annular cold water pipe 9) - main inlet and outlet water regulating valve opening (i.e., the opening of inlet regulating valve 11 and outlet regulating valve 17), branch regulating valve opening (i.e., the opening of branch regulating valve 15)" is consulted to obtain the main inlet and outlet water regulating valve opening and the branch regulating valve opening.

[0071] In one implementation of this invention, the multiple annular cold water pipes 9 in the waste heat recovery device can be connected in parallel to a set of heat circulation pipes, that is, heat energy recovery is carried out on the multiple annular cold water pipes 9 connected in parallel through a set of heat circulation pipes.

[0072] In another implementation of the present invention, for each annular cold water pipe 9 in the waste heat recovery device, a set of heat circulation pipelines can be configured, that is, each annular cold water pipe 9 implements heat energy recovery through an independent heat circulation pipeline, which is more efficient in heat energy recovery, but requires the hardware configuration of multiple sets of heat circulation pipelines.

[0073] Furthermore, such as Figure 5 As shown, the waste heat recovery system provided in this embodiment of the invention can also be equipped with a storage tank. The storage tank is specifically set between the rear end of the outlet switch valve 18 of the outlet water pipe and the load, and is used to store high-temperature water from the outlet water pipe to ensure stable operation of the load. For example, a storage tank can be set at the front end of loads such as domestic hot water and heating.

[0074] Based on the waste heat recovery system for an indoor test stand for an aero-engine provided in the above embodiments of the present invention, the present invention also provides a waste heat recovery method for an indoor test stand for an aero-engine. The waste heat recovery method is performed using the waste heat recovery system provided in any of the above embodiments of the present invention, and the waste heat recovery method includes the following implementation steps:

[0075] Step 1: Based on the temperature distribution characteristics of the exhaust gas inside the ejector tube 3 in the indoor test stand of the aero-engine, determine the number of annular cooling water pipes 9 and their axial placement in the ejector tube 3.

[0076] In this step, the temperature distribution characteristics of the exhaust gas inside the ejector tube 3 can be obtained through CFD aerodynamic simulation on the test bench, and the axial layout position of the annular cold water pipe 9 determined in this step is also the axial layout position of the I-shaped heat pipe on the outer wall of the ejector tube 3.

[0077] Step 2: Based on the CFD multiphase flow simulation of the I-shaped heat pipe, by comparing the heat transfer efficiency of I-shaped heat pipes with different lengths of adiabatic section 7 and different layout forms of I-shaped heat pipes (including the number and location of the pipes), the length of the adiabatic section 7 and the layout form of the I-shaped heat pipes used for waste heat recovery on the current test bench are determined.

[0078] The waste heat recovery method provided in this embodiment of the invention, through CFD simulation in steps 1 and 2 above, can determine the structure and layout of the annular cold water pipe 9 and the I-shaped heat pipes in the waste heat recovery system used to perform the waste heat recovery method for test benches with different structures and performance parameters. For example, the annular diameter, number, and layout position of the annular cold water pipe 9, and the length, number, and layout position of the insulation section 7 of the I-shaped heat pipes arranged inside the annular cold water pipe 9.

[0079] Step 3: After connecting the hot circulation pipeline to each annular cold water pipe 9, perform waste heat recovery on the indoor test stand of the aero-engine under various test conditions.

[0080] In step 3, during the waste heat recovery process of the test stand under different test conditions, it is necessary to adjust the inlet cold water temperature of the annular cold water pipe 9 by adjusting the opening of the inlet regulating valve 11 and the branch regulating valve 15. As described in the above embodiments, the test of an aero-engine generally includes four operating conditions: idle, 0.8 rated power, intermediate, and afterburner.

[0081] Considering the significant variations in exhaust flow and temperature of the test bench under different test conditions, resulting in substantial temperature variations on the outer wall of the ejector tube 3 and consequently significant variations in heat exchange or waste heat recovery, this embodiment of the invention can adjust not only the cold water flow rate of the annular cold water pipe 9 but also the inlet cold water temperature of the annular cold water pipe 9 for different test conditions.

[0082] In practice, by setting a return branch pipe in the outlet water pipe, the inlet cold water temperature is controlled to regulate the heat exchange, thereby effectively improving the regulation range, control accuracy, stability, and response speed of the heat exchange. Specifically, the inlet cold water temperature control scheme can be an online lookup table method. Based on the real-time temperature of the outer wall of the ejector tube 3, a pre-set mapping table of "ejector tube outer wall temperature - inlet cold water temperature (i.e., the inlet temperature of the annular cold water pipe 9) - main inlet and outlet water regulating valve opening (i.e., the opening of inlet regulating valve 11 and outlet regulating valve 17), branch regulating valve opening (i.e., the opening of branch regulating valve 15)" is consulted to obtain the main inlet and outlet water regulating valve opening and the branch regulating valve opening.

[0083] For the above four test conditions, the pre-set mapping table shows the following relationship between the ejector tube outer wall temperature, inlet cold water temperature, inlet regulating valve 11 opening degree, and branch regulating valve 15 opening degree for each of the four test conditions:

[0084]

[0085] In one specific embodiment of the present invention, in a set of hot circulation pipelines connected to a ring-shaped cold water pipeline 9, if the specifications of the inlet regulating valve 11, the branch regulating valve 15 and the outlet regulating valve 17 are the same, during the opening adjustment process, the sum of the openings of the inlet regulating valve 11 and the branch regulating valve 15 is 100%, and the openings of the inlet regulating valve 11 and the outlet regulating valve 17 are consistent.

[0086] The waste heat recovery device, system, and method for an indoor test stand for an aero-engine provided in this embodiment of the invention are formed by reasonably arranging multiple I-shaped heat pipes and multiple annular cold water pipes 9 on the outer wall of the ejector tube 3 to form a waste heat recovery device, and by setting up a heat circulation pipeline for the waste heat recovery device to form a waste heat recovery system, thereby implementing a waste heat recovery method using a waste heat recovery system. In the aforementioned waste heat recovery technical solution, on the one hand, by structurally modifying the evaporator end 6 and condenser end 8 of a conventional straight heat pipe, an I-shaped heat pipe is formed that can be adapted to the outer wall surface of the ejector tube 3 and the outer wall surface of multiple annular cold water pipes 9, thereby implementing heat exchange between the ejector tube 3 and the annular cold water pipes 9; on the other hand, CFD aerodynamic simulation based on a test bench is used to obtain the temperature distribution of the exhaust gas inside the ejector tube 3, thereby correspondingly arranging the I-shaped heat pipes and annular cold water pipes 9 in the area with higher exhaust gas temperature on the outer wall surface of the ejector tube 3; in addition, CFD multiphase flow simulation based on the I-shaped heat pipe is used to determine the heat transfer efficiency under different lengths of adiabatic section 7 and by comparing different arrangement forms of I-shaped heat pipes (including the number and location of arrangement), thus confirming the heat transfer efficiency. The optimal structure and layout of the I-shaped heat pipes were determined. Furthermore, considering the significant variations in exhaust flow and temperature on the test bench under various test conditions during aero-engine testing, resulting in substantial temperature variations on the outer wall of the ejector tube 3 and consequently significant variations in heat exchange or waste heat recovery, a return branch pipe was installed on the outlet water pipe. The opening of the branch regulating valve 15 in the return branch pipe and the inlet regulating valve 11 in the inlet water pipe were used to control the inlet cold water temperature, thereby adjusting the heat exchange and improving the adjustment range, control accuracy, stability, and response speed of the heat exchange. Additionally, a storage tank was installed at the front end of the load to store high-temperature water from the outlet water pipe, ensuring stable load operation.

[0087] The technical solution provided by this invention, through adaptability modifications to conventional straight heat pipes, optimizes the shape, structure, and layout of I-shaped heat pipes, and provides a control scheme for adjusting the inlet chilled water temperature and an online lookup table control strategy. This solves the waste heat recovery problem of indoor test benches for aero-engines, achieving efficient recovery of waste heat and improving the energy utilization rate of the test bench. It possesses high practicality and advanced features and can be widely applied to indoor test benches for aero-engines. Furthermore, this waste heat recovery scheme has advantages such as strong adaptability, high stability, and high control precision, and can meet the waste heat recovery requirements under different test conditions.

[0088] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A waste heat recovery device for an aeroengine cell, characterized in that, The indoor test stand for the aircraft engine is equipped with an exhaust system. The exhaust system uses an ejector tube (3) located in the ejector chamber (2) to eject the high-temperature, high-speed exhaust gas from the engine tail nozzle to the ambient temperature gas in the test workshop (1). After the exhaust gas is mixed with the ejector, its temperature and velocity decrease, and it is discharged into the exhaust tower (4). The waste heat recovery device includes: Multiple annular cold water pipes (9) are arranged at intervals along the axial direction on the outer wall of the ejector tube (3). In the annular plane formed by each annular cold water pipe (9) and the ejector tube (3), multiple I-shaped heat pipes are arranged in the circumferential direction. The annular cold water pipes (9) are fixedly supported on the outer wall of the ejector tube (3) by the multiple I-shaped heat pipes arranged in the circumferential direction. Each of the I-shaped heat pipes includes an evaporation end (6) and a condensation end (8) configured as an arc segment, and an adiabatic section (7) for connecting the evaporation end (6) and the condensation end (8). The closed connecting cavity formed by the evaporation end (6), the adiabatic section (7) and the condensation end (8) is filled with a liquid working fluid located at the evaporation end (6). After each of the I-shaped heat pipes is installed, the evaporation end (6) located on the inner side is attached to the outer wall of the ejector tube (3), and the condensation end (8) located on the outer side is attached to the inner wall of the annular cold water pipe (9) at the corresponding installation position. This is used to evaporate the liquid working fluid in the evaporation end (6) into gas through the heat energy in the ejector tube (3). After the gas passes through the insulation section (7) to the condensation end (8), the gas in the condensation end (8) is liquefied by the cold water flowing in the annular cold water pipe (9) and then returns to the evaporation end (6), thereby forming a heat exchange with the annular cold water pipe (9) to recover the heat energy of the exhaust gas in the ejector tube (3). In the I-shaped heat pipe, the inner wall surface of the evaporation end (6) is set as an arc-shaped surface along the installation circumference, and is in contact with the outer wall surface of the ejector tube (3); The outer wall of the condenser end (8) is recessed inward along the installation circumference to form a semi-circular groove, so as to embed the inner ring wall of the annular cold water pipe (9) into the semi-circular groove; The positions of the multiple annular cold water pipes (9) along the axial direction of the ejector tube (3) are determined based on the temperature distribution of the exhaust gas inside the ejector tube (3). The annular cold water pipes (9) arranged at intervals along the axial direction of the ejector tube (3) have the same annular diameter, or the annular diameters of the multiple annular cold water pipes (9) are different. The arrangement of the I-shaped heat pipes on the outer wall of the ejector tube (3) is determined according to the temperature distribution of the exhaust gas inside the ejector tube (3). The arrangement of the I-shaped heat pipes includes the number of pipes and their positions.

2. The waste heat recovery device for the indoor test stand of an aero-engine according to claim 1, characterized in that, By adjusting the number and location of the I-shaped heat pipes, as well as the length of the insulating section (7) in the I-shaped heat pipes, the waste heat recovery device can be applied to the heat recovery of ejector tubes (3) with different exhaust temperature distributions.

3. A waste heat recovery system for an aeroengine cell, characterized in that, include: The waste heat recovery device as described in any one of claims 1 to 2, and at least one set of heat circulation pipeline; The hot circulation pipeline includes: an inlet pipe connected to the front end of the annular cold water pipe (9) and an outlet pipe connected to the rear end of the annular cold water pipe (9); the inlet pipe is connected in sequence to an inlet switch valve (10), an inlet regulating valve (11), a filter (12), a circulation pump (13), a flow meter, and a temperature sensor; the outlet pipe is connected in sequence to an outlet switch valve (14), an outlet regulating valve (17), and an outlet switch valve (18); and a return branch pipe is provided at the rear end of the outlet switch valve (14); the other end of the return branch pipe is connected to the inlet pipe between the inlet regulating valve (11) and the filter (12); and a branch regulating valve (15) and a branch switch valve (16) are connected in sequence on the return branch pipe. The heat circulation pipeline is used to provide low-temperature water through the inlet pipeline. The low-temperature water is pressurized by the circulation pump (13) and enters the annular cold water pipeline (9). After heat exchange between the annular cold water pipeline (9) and the I-shaped heat pipe, high-temperature water flows out. Part of the high-temperature water flows out through the outlet pipeline to achieve recycling. The other part of the high-temperature water is mixed with the low-temperature water in the inlet pipeline through the return branch pipeline to form a circulation loop.

4. The system for recovering waste heat from an aeroengine test cell according to claim 3, wherein, The test runs conducted on the indoor test bench for the aero-engine have a variety of test conditions. The waste heat recovery system adjusts the inlet cold water temperature of the annular cold water pipe (9) by adjusting the opening of the inlet regulating valve (11) and the branch regulating valve (15), thereby meeting the heat energy recovery requirements of the outer wall temperature of the ejector tube (3) under different test conditions.

5. The waste heat recovery system for the indoor test stand of an aero-engine according to claim 3, characterized in that, The multiple annular cold water pipes (9) in the waste heat recovery device are connected in parallel to a set of heat circulation pipes; or... Each of the annular cold water pipes (9) in the waste heat recovery device is equipped with a set of heat circulation pipelines.

6. The system for recovering waste heat from an aeroengine test cell according to claim 3, wherein, Also includes: Storage tanks; A storage tank is provided between the rear end of the outlet switch valve (18) of the water outlet pipeline and the load to store high-temperature water from the water outlet pipeline, so that the load can operate stably.

7. A method of recovering waste heat from an aeroengine test cell, characterized in that, The waste heat recovery method for the indoor test stand of an aero-engine is implemented using the waste heat recovery system of any one of claims 3 to 6, wherein the waste heat recovery method includes: Step 1: Based on the temperature distribution of the exhaust gas inside the ejector tube (3) in the aircraft engine indoor test stand, determine the number of annular cooling water pipes (9) and their axial placement in the ejector tube (3). Step 2: Based on the CFD multiphase flow simulation of the I-shaped heat pipe, by comparing the heat transfer efficiency of the I-shaped heat pipe with different lengths of adiabatic section (7) and the arrangement of different I-shaped heat pipes, the length of the adiabatic section (7) and the arrangement of the I-shaped heat pipes used for waste heat recovery on the current test bench are determined. Step 3: After connecting the heat circulation pipeline to each annular cold water pipe (9), perform waste heat recovery on the indoor test bench of the aero-engine under various test conditions. In the process of waste heat recovery for different test driving conditions, the inlet cold water temperature of the annular cold water pipeline (9) is adjusted by adjusting the opening degree of the inlet adjusting valve (11) and the branch adjusting valve (15).

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