Low power air heat exchanger performance test bench

Abstract

This application relates to the field of heat exchanger performance testing technology, and in particular to a low-power air heat exchanger performance test bench, comprising a first pipe equipped with a heater, a second pipe, a third pipe equipped with a cooler, and a fourth pipe. The control and display system obtains the hot / cold edge flow resistance of the air heat exchanger under test based on the total inlet pressure and outlet pressure of the hot / cold edge. Based on the diameter of the first pipe, the total inlet pressure and static pressure of the hot / cold edge, and the inlet temperature of the hot / cold edge, the mass flow rate at the inlet of the air heat exchanger under test is calculated. Based on multiple sets of correspondences between the hot / cold edge flow resistance and the mass flow rate at the inlet, a fitting curve of the hot / cold edge flow resistance versus mass flow rate of the air heat exchanger under test is fitted. Simultaneously, the flow state of the hot and cold edges is simulated, and the flow resistance and mass flow rate of the hot and cold edges are precisely controlled and measured to effectively evaluate the flow resistance performance of the air heat exchanger.

Description

Technical Field

[0001] This application relates to the field of heat exchanger performance testing technology, and in particular to a low-power air heat exchanger performance test bench. Background Technology

[0002] Heat exchangers are devices that transfer heat between hot and cold fluids, and are an important component for energy conservation and consumption reduction in special equipment. Air-cooled heat exchangers (or simply air coolers) are heat exchange devices in which ambient air, driven by a fan, sweeps across finned heat exchange tubes to cool the process fluid inside the tubes. They are core equipment in large-scale complete sets of equipment and are widely used in industries such as petroleum, chemical, pharmaceutical, power, metallurgy, and energy. Compared to water cooling, air coolers have significant advantages such as better water conservation, less environmental pollution, lower operating costs, and longer service life. In northern regions with suitable climates, air coolers offer better economic performance than cooling towers.

[0003] Currently, there are various methods and indicators for evaluating heat exchanger performance. These include methods and indicators based on the first law of thermodynamics, such as specific pressure drop J = Δp / NTU, energy coefficient (the ratio of heat flow to pump work), and area mass factor (the ratio of heat transfer factor j to friction resistance coefficient f). However, current research on high-efficiency heat exchangers focuses only on the heat transfer rate, i.e., only on the concept of heat transfer enhancement without considering heat transfer optimization. In reality, while high-efficiency heat exchangers enhance heat transfer, they inevitably lead to increased flow resistance, thereby increasing the energy consumption of pumps or fans. Therefore, in addition to studying the heat transfer rate, it is also necessary to effectively evaluate the flow resistance performance of high-efficiency heat exchangers. Summary of the Invention

[0004] In order to effectively evaluate the flow resistance performance of high-efficiency heat exchangers, this application provides a low-power air heat exchanger performance test bench.

[0005] The low-power air heat exchanger performance test bench provided in this application adopts the following technical solution:

[0006] A low-power air heat exchanger performance test bench, comprising:

[0007] The first pipe has one end connected to the hot edge inlet of the air heat exchanger under test, and the other end connected to the fan. A heater is provided on the first pipe.

[0008] The second pipe has one end connected to the hot edge outlet of the air heat exchanger under test.

[0009] The third pipe has one end connected to the cold side inlet of the air heat exchanger under test, and the other end connected to the fan. A cooler is provided on the third pipe.

[0010] The fourth pipe has one end connected to the cold side outlet of the air heat exchanger under test;

[0011] The temperature measuring assembly includes a first temperature sensor disposed on the first pipe and measuring the hot side inlet temperature, and a third temperature sensor disposed on the third pipe and measuring the cold side inlet temperature.

[0012] The pressure measuring assembly includes a first total pressure sensor and a first static pressure sensor installed on the first pipe to measure the total pressure at the hot edge inlet and the static pressure at the hot edge inlet; a second total pressure sensor installed on the second pipe to measure the total pressure at the hot edge outlet; a third total pressure sensor installed on the third pipe to measure the total pressure at the cold edge inlet and the static pressure at the cold edge inlet; and a fourth total pressure sensor installed on the fourth pipe to measure the total pressure at the cold edge outlet.

[0013] The system includes a control and display unit connected to the temperature and pressure measuring components. It calculates the hot-side flow resistance of the tested air heat exchanger based on the total pressure at the hot-side inlet and outlet. It also calculates the mass flow rate at the hot-side inlet of the tested air heat exchanger based on the diameter of the first pipe, the total pressure and static pressure at the hot-side inlet, and the temperature at the hot-side inlet. The system further calculates the cold-side flow resistance of the tested air heat exchanger based on the total pressure at the cold-side inlet and outlet. By adjusting the fan speed, the system calculates the mass flow rate at the cold-side inlet of the tested air heat exchanger based on the diameter of the first pipe, the total pressure and static pressure at the cold-side inlet, and the temperature at the cold-side inlet. Finally, it fits a curve showing the relationship between the hot-side flow resistance and the mass flow rate at the hot-side inlet, and a curve showing the relationship between the cold-side flow resistance and the mass flow rate at the cold-side inlet.

[0014] By employing the above technical solution and simulating the flow states at both hot and cold sides, the temperature and pressure measuring components monitor temperature and pressure changes in real time. Combined with the data processing capabilities of the control and display systems, the flow resistance and mass flow rate of the hot and cold sides can be accurately calculated, and a curve showing the relationship between flow resistance and mass flow rate can be fitted. Through precise control and measurement of the flow resistance and mass flow rate of the hot and cold sides, the flow resistance performance of the air heat exchanger can be effectively evaluated.

[0015] Optionally, the temperature measuring assembly further includes a second temperature sensor disposed on the second pipe and measuring the hot edge outlet temperature, and a fourth temperature sensor disposed on the fourth pipe and measuring the cold edge outlet temperature.

[0016] The control and display determine the temperature efficiency of the tested air heat exchanger based on the hot edge inlet temperature, hot edge outlet temperature, cold edge inlet temperature, and cold edge outlet temperature.

[0017] Adjust the hot-side flow rate and cold-side flow rate, and obtain the flow rate ratio. Based on the correspondence between multiple sets of flow rate ratios and temperature efficiency, fit the curve of the flow rate ratio and temperature efficiency of the tested air heat exchanger.

[0018] By adopting the above technical solution, adjusting the flow rates of the hot and cold sides, and obtaining the flow rate ratio, the test bench can fit the fitting curve of the flow rate ratio and temperature efficiency of the tested air heat exchanger based on the correspondence between multiple sets of flow rate ratios and temperature efficiency. This provides richer data support for the performance analysis of the heat exchanger and helps to achieve more efficient energy utilization and better heat exchanger design.

[0019] Optionally, the second pipe reverts to the third pipe and communicates with the third pipe, with the cooler located downstream of the second pipe.

[0020] By adopting the above technical solution, the air in the second pipe flows back to the third pipe, and heat exchange occurs through the cooler, thus recovering the heat of the air in the second pipe.

[0021] Optionally, an induced air mixer is connected to the connection between the third pipe and the second pipe.

[0022] By adopting the above technical solution, the mixing of air in the second pipe and air in the third pipe can be promoted.

[0023] Optionally, the third pipe is equipped with a rectifier and is located downstream of the second pipe.

[0024] By adopting the above technical solution, the air in the third pipe is rectified.

[0025] Optionally, the fourth pipe is reconnected to the first pipe, and both the fourth pipe and the first pipe are connected to the regenerator, which is located upstream of the heater.

[0026] By adopting the above technical solution, the air in the fourth pipe can preheat the air in the first pipe through the regenerator, and the heat of the air in the fourth pipe can be recovered.

[0027] Optionally, a rectifier is provided on the fourth pipe.

[0028] By adopting the above technical solution, the air in the fourth pipe is rectified so that the air in the fourth pipe can flow to the regenerator, thereby improving the heat exchange efficiency.

[0029] Optionally, the third pipe is provided with a first regulating valve, and the fourth pipe is provided with a fourth regulating valve.

[0030] By adopting the above technical solution, the cold side flow rate of the tested air heat exchanger can be adjusted.

[0031] Optionally, a fifth pipe is connected to the third pipe, and a second regulating valve is provided on the fifth pipe.

[0032] Optionally, a sixth pipe is connected to the second pipe, and the sixth pipe is provided with a third regulating valve.

[0033] By adopting the above technical solution, the performance of the hot-side pipes of the air heat exchanger can be tested separately.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. Simultaneously, the flow states at both hot and cold sides are simulated. Temperature and pressure sensing components monitor temperature and pressure changes in real time. Combined with the data processing capabilities of the control and display systems, the flow resistance and mass flow rate of the hot and cold sides can be accurately calculated, and a curve showing the relationship between flow resistance and mass flow rate can be fitted. By precisely controlling and measuring the flow resistance and mass flow rate of the hot and cold sides, the flow resistance performance of the air heat exchanger can be effectively evaluated.

[0036] 2. Adjust the flow rates of the hot and cold sides and obtain the flow rate ratio. The test bench can fit the fitting curve of the flow rate ratio and temperature efficiency of the tested air heat exchanger based on the correspondence between multiple sets of flow rate ratios and temperature efficiency, providing richer data support for the performance analysis of the heat exchanger.

[0037] 3. The fourth pipe returns to the first pipe. Both the fourth pipe and the first pipe are connected to the regenerator. The regenerator is located upstream of the heater. The air in the fourth pipe can preheat the air in the front section of the first pipe through the regenerator, and the heat of the air in the fourth pipe can be recovered. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the low-power air heat exchanger performance test bench in the embodiments of this application;

[0039] Figure 2 This is a schematic diagram of the control and display structure in an embodiment of this application.

[0040] Explanation of reference numerals in the attached figures:

[0041] 100. Test air heat exchanger; 1. First pipe; 11. Fan; 12. Heater; 2. Second pipe; 3. Third pipe; 31. Cooler; 32. Induced air mixer; 33. Rectifier; 4. Fourth pipe; 41. Regenerator; 5. Fifth pipe; 6. Sixth pipe; 1a. First temperature sensor; 1b. Second temperature sensor; 1c. Third temperature sensor; 1d. Fourth temperature sensor; 2a. First total pressure sensor; 2b. Second total pressure sensor; 2c. Third total pressure sensor; 2d. Fourth total pressure sensor; 3a. First static pressure sensor; 3b. Second static pressure sensor; 3c. Third static pressure sensor; 3d. Fourth static pressure sensor; 4a. First regulating valve; 4b. Second regulating valve; 4c. Third regulating valve; 4d. Fourth regulating valve. Detailed Implementation

[0042] The following will be combined with the appendix Figure 1-2 The technical solutions in the embodiments of this application are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0043] This application discloses a performance test bench for a low-power air heat exchanger. (Refer to...) Figure 1 The low-power air heat exchanger performance test bench is used to test the air heat exchanger 100 under test. It includes a first pipe 1, a second pipe 2, a third pipe 3, a fourth pipe 4, a heater 12, a cooler 31, a temperature measuring component, a pressure measuring component, and a control and display.

[0044] The test air heat exchanger 100 has a hot-side inlet, a hot-side outlet, a cold-side inlet, and a cold-side outlet. One end of the first pipe 1 is connected to the hot-side inlet of the test air heat exchanger 100, and the other end is connected to a fan 11. The fan 11 is a high-pressure centrifugal fan with a maximum operating pressure of 12 kPa, a maximum flow rate of 1500 kg / h, a power distribution of 75 kW, and variable frequency speed control. A heater 12 is installed on the first pipe 1; in this embodiment, the heater 12 is an electromagnetic heater 12. The second pipe 2 is connected to the hot-side outlet of the test air heat exchanger 100. When the fan 11 is started, ambient temperature air flows into the test air heat exchanger 100 through the first pipe 1 from the hot-side inlet. The heater 12 heats the air in the first pipe 1, and then the air flows out through the second pipe 2.

[0045] One end of the third pipe 3 is connected to the cold-side inlet of the test air heat exchanger 100, and the other end is connected to the fan 11. A cooler 31 is installed on the third pipe 3. One end of the fourth pipe 4 is connected to the cold-side outlet of the test air heat exchanger 100. When the fan 11 is started, ambient temperature air flows into the test air heat exchanger 100 from the cold-side inlet through the third pipe 3. The cooler 31 cools the air in the third pipe 3, and then the air flows out through the fourth pipe 4. In this embodiment, the cooler 31 is a water-cooled heat exchanger.

[0046] The heated air flows through the hot side pipe of the test air heat exchanger 100, and the cooled air flows through the cold side pipe of the test air heat exchanger 100. During this process, heat exchange occurs between the heated air and the cooled air.

[0047] The airflow rate in each pipe can be adjusted by regulating the rotation speed of the fan 11. In this embodiment, the first pipe 1 and the third pipe 3 are connected and both are connected to the fan 11. Starting the fan 11 allows air to be simultaneously introduced into the hot-side pipe and the cold-side pipe of the air heat exchanger 100 under test. The third pipe 3 is equipped with a first regulating valve 4a. Adjusting the angle of the first regulating valve 4a can regulate the cold-side flow rate of the air heat exchanger 100 under test.

[0048] To improve heat utilization, the second pipe 2 is redirected to and connected to the third pipe 3, and the cooler 31 is located downstream of the second pipe 2. The air in the second pipe 2 flows back into the third pipe 3, where it undergoes heat exchange through the cooler 31, thus recovering the heat from the air in the second pipe 2.

[0049] An induced air mixer 32 is connected at the connection between the third pipe 3 and the second pipe 2, which can promote the mixing between the air in the second pipe 2 and the air in the third pipe 3.

[0050] When the air in the second pipe 2 mixes with the air in the third pipe 3, turbulence is generated. The third pipe 3 is equipped with a rectifier 33, which is located downstream of the second pipe 2, and can rectify the mixed air. The second pipe 2 is connected to a sixth pipe 6, and the sixth pipe 6 is equipped with a third regulating valve 4c.

[0051] The fourth pipe 4 returns to the first pipe 1. Both the fourth pipe 4 and the first pipe 1 are connected to the regenerator 41, which is located upstream of the heater 12. The air in the fourth pipe 4 can preheat the air in the first pipe 1 through the regenerator 41, thus recovering the heat of the air in the fourth pipe 4.

[0052] A rectifier 33 is also provided on the fourth pipe 4 to rectify the air inside the fourth pipe 4, so that the air inside the fourth pipe 4 flows to the regenerator 41, thereby improving the heat exchange efficiency. A fourth regulating valve 4d is provided on the fourth pipe 4. Adjusting the angle of the fourth regulating valve 4d can adjust the cold side flow rate of the tested air heat exchanger 100. A fifth pipe 5 is connected to the third pipe 3, and a second regulating valve 4b is provided on the fifth pipe 5.

[0053] The temperature measuring assembly includes a first temperature sensor 1a installed on the first pipe 1 to measure the inlet temperature of the hot side, a second temperature sensor 1b installed on the second pipe 2 to measure the outlet temperature of the hot side, a third temperature sensor 1c installed on the third pipe 3 to measure the inlet temperature of the cold side, and a fourth temperature sensor 1d installed on the fourth pipe 4 to measure the outlet temperature of the cold side.

[0054] The pressure measuring assembly includes a first total pressure sensor 2a and a first static pressure sensor 3a installed on the first pipe 1 to measure the total pressure at the hot edge inlet; a second total pressure sensor 2b and a second static pressure sensor 3b installed on the second pipe 2 to measure the total pressure at the hot edge outlet; a third total pressure sensor 2c and a third static pressure sensor 3c installed on the third pipe 3 to measure the total pressure at the cold edge inlet; and a fourth total pressure sensor 2d and a fourth static pressure sensor 3d installed on the fourth pipe 4 to measure the total pressure at the cold edge outlet.

[0055] All regulating valves are electrically operated. The control and display are connected to each regulating valve, fan 11, heater 12, cooler 31, etc., to realize automatic control of each component.

[0056] The control and display are connected to the temperature and pressure measurement components to acquire data monitored by each temperature and pressure sensor, and to obtain a fitting curve based on the data.

[0057] Under the action of the high-pressure centrifugal fan 11, room temperature air is divided into two streams and enters the cold and hot sides of the test air heat exchanger 100 to conduct flow resistance tests on the cold and hot sides simultaneously. After the condition stabilizes, the system automatically records data such as total pressure, static pressure and temperature of the cold and hot sides.

[0058] By adjusting the pipe flow rate multiple times, the total pressure at the hot side inlet and the total pressure at the hot side outlet after each adjustment can be measured, thereby calculating the hot side flow resistance after each adjustment.

[0059] Specifically, the control and display obtain the hot edge flow resistance on the test air heat exchanger 100 based on the total pressure at the hot edge inlet and the total pressure at the hot edge outlet.

[0060] The formula for the hot edge flow resistance ΔPR is:

[0061] ΔPRi =P 1i * -P 2i * ;

[0062] Where: ΔPR i The thermal side resistance is the value of the pipe flow rate during the i-th adjustment.

[0063] i represents the number of times the pipe flow rate is adjusted, i = 1, 2, 3...;

[0064] P 1i * The total pressure at the hot side inlet, measured during the i-th adjustment of the pipeline flow rate, is expressed in Pa.

[0065] P 2i * The total pressure at the hot side outlet is measured during the i-th adjustment of the pipeline flow rate, in Pa.

[0066] For example, after the first adjustment of the pipeline flow rate at the hot edge, the total pressure at the inlet and outlet of the hot edge is measured as P. 11 * P 21 * Then, during the first adjustment, the hot-side flow resistance ΔPR1 = P 11 * -P 21 * .

[0067] By adjusting the speed of fan 11 and various regulating valves, the pipeline flow rate can be adjusted multiple times. The total pressure, static pressure, temperature, and other data of the inlet and outlet of the hot and cold sides after each adjustment can be measured, thereby calculating the mass flow rate of the hot and cold sides after each adjustment.

[0068] Specifically, the control and display determine the mass flow rate of the hot side inlet of the tested air heat exchanger 100 based on the diameter of the first pipe 1, the total pressure and static pressure of the hot side inlet, and the temperature of the hot side inlet.

[0069] The formula for the hot edge mass flow rate is:

[0070]

[0071] Where: d1 is the diameter of the hot-side flow pipe (i.e., the diameter of the first pipe), in meters;

[0072] P 1i P 1i * The static pressure and total pressure at the hot-side inlet are measured during the i-th adjustment of the pipeline flow rate, in Pa.

[0073] R = 287.4 kJ / kg·K;

[0074] T 1i The temperature at the hot side inlet measured during the i-th adjustment of the pipeline flow rate, in K;

[0075] G Ri The mass flow rate of the hot-side pipeline during the i-th adjustment of the pipeline flow rate is expressed in kg / s.

[0076] For example, the mass flow rate of the hot-side pipeline during the first adjustment of the pipeline flow rate is:

[0077]

[0078] The control and display system fits the curves of the hot edge flow resistance and mass flow rate of the tested air heat exchanger 100 based on the correspondence between multiple sets of hot edge flow resistance and hot edge inlet mass flow rate.

[0079] Similarly, by adjusting the pipe flow rate multiple times, the total pressure at the cold side inlet and the total pressure at the cold side outlet after each adjustment can be measured, thereby calculating the cold side flow resistance after each adjustment.

[0080] Specifically, the control and display system calculates the cold-side flow resistance on the tested air heat exchanger 100 based on the total pressure at the cold-side inlet and outlet. The formula for the cold-side flow resistance ΔPL is:

[0081] ΔPL i =P 3i * -P 4i * ;

[0082] Where: ΔPL i The cold side flow resistance is the value of the pipe flow rate when the flow rate is adjusted for the i-th time.

[0083] i represents the number of times the pipe flow rate is adjusted, i = 1, 2, 3...;

[0084] P 3i * The total pressure at the cold side inlet, measured during the i-th adjustment of the pipe flow rate, is expressed in Pa.

[0085] P 4i * The total pressure at the cold side outlet, measured during the i-th adjustment of the pipeline flow rate, is expressed in Pa.

[0086] Adjust the speed of fan 11 and the various regulating valves to regulate the flow rate in the pipeline. Based on the diameter of the first pipeline 1, the total pressure and static pressure at the cold side inlet, and the temperature at the cold side inlet, the mass flow rate at the cold side inlet of the tested air heat exchanger 100 is obtained.

[0087] The formula for the mass flow rate of the cold edge is:

[0088]

[0089] Where: d2 is the diameter of the cold side flow pipe (i.e., the diameter of the third pipe), in meters;

[0090] P 3i P 3i * The static pressure and total pressure at the cold side inlet are measured during the i-th adjustment of the pipeline flow rate, in Pa.

[0091] R = 287.4 kJ / kg·K;

[0092] T 3i The temperature at the cold side inlet, measured during the i-th adjustment of the pipe flow rate, is expressed in K.

[0093] G Li The mass flow rate of the cold side pipeline during the i-th adjustment of the pipeline flow rate is expressed in kg / s.

[0094] For example, the mass flow rate of the cold-side pipeline during the first adjustment of the pipeline flow rate is:

[0095]

[0096] By repeating this process and coordinating the operation of several electrically adjustable valves, combined with the adjustment of the fan speed 11, a set of flow resistance-mass flow rate points for the cold and hot sides (generally 5 to 7 points) can be obtained. The control and display automatically fit the cold and hot side flow resistance curves of the tested air heat exchanger 100 using the least squares method. That is, based on the correspondence between multiple sets of cold side flow resistances and the mass flow rate at the cold side inlet, the fitting curve of the cold side flow resistance and mass flow rate of the tested air heat exchanger 100 is obtained.

[0097] The controller and display adjust the hot-side flow rate and cold-side flow rate to their target values ​​by adjusting the corresponding electric regulating valve or fan 11 speed according to the possible variation range of the hot-side inlet temperature and the possible corresponding flow rate of the air heat exchanger. By adjusting the power of the electromagnetic heater 12 and the flow rate of the cooling water in the cooler 31, the hot-side air supply temperature and cold-side air supply temperature are made equal to their target temperature values.

[0098] Once the system stabilizes, the inlet and outlet air temperatures at the hot and cold sides of the heat exchanger are automatically recorded. The formula for the temperature efficiency of the air heat exchanger under these conditions is:

[0099] Where T1 is the temperature of the hot edge inlet;

[0100] T2 is the temperature of the hot edge outlet;

[0101] T3 is the temperature at the cold edge inlet;

[0102] T4 is the temperature at the cold edge outlet.

[0103] By repeating this process, the efficiency curves of the heat exchanger under different flow ratios (the ratio of hot-side flow rate to cold-side flow rate) can be obtained. That is, based on the correspondence between multiple flow ratios and temperature efficiency, the fitting curve of the flow ratio and temperature efficiency of the tested air heat exchanger can be obtained.

[0104] The control and display panel features a main display screen that visually shows the fitting curves of the hot and cold side flow resistance versus mass flow rate of the tested air heat exchanger 100, and the fitting curve of the flow rate ratio versus temperature efficiency of the tested air heat exchanger 100. The control and display panel includes switches for controlling the opening and closing of the heater 12 and cooler 31, switches for controlling the opening and closing of each electric valve, knobs for adjusting the hot and cold flow rates, and knobs for adjusting the current and voltage of the fan 11. The control and display panel also displays the following temperatures: hot side inlet temperature T1, hot side outlet temperature T2, cold side inlet temperature T3, cold side outlet temperature T4, static pressure P1 at the hot side inlet, static pressure P2 at the hot side outlet, static pressure P3 at the cold side inlet, static pressure P4 at the cold side outlet, and total pressure P1 at the hot side inlet. * Total pressure P2 at the hot edge outlet * Total pressure P3 at the cold edge inlet * Total pressure P4 at the cold edge outlet * The display area.

[0105] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0106] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0107] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A low-power air heat exchanger performance test bench, characterized in that, include: The first pipe (1) is connected at one end to the hot side inlet of the air heat exchanger (100) under test, and at the other end to the fan (11). A heater (12) is provided on the first pipe (1). The second pipe (2) is connected at one end to the hot side outlet of the air heat exchanger (100) under test; The third pipe (3) is connected at one end to the cold side inlet of the air heat exchanger (100) under test, and at the other end to the fan (11). A cooler (31) is provided on the third pipe (3). The fourth pipe (4) is connected at one end to the cold side outlet of the air heat exchanger (100) under test; the temperature measuring assembly includes a first temperature sensor (1a) installed on the first pipe (1) and measuring the hot side inlet temperature, and a third temperature sensor (1c) installed on the third pipe (3) and measuring the cold side inlet temperature. The pressure measuring assembly includes a first total pressure sensor (2a) and a first static pressure sensor (3a) installed on the first pipe (1) to measure the total pressure at the hot edge inlet, a second total pressure sensor (2b) installed on the second pipe (2) to measure the total pressure at the hot edge outlet, a third total pressure sensor (2c) installed on the third pipe (3) to measure the total pressure at the cold edge inlet and a third static pressure sensor (3c) to measure the static pressure at the cold edge inlet, and a fourth total pressure sensor (2d) installed on the fourth pipe (4) to measure the total pressure at the cold edge outlet. Control and display, connected to the temperature measuring component and pressure measuring component; obtain the hot-side flow resistance on the test air heat exchanger (100) based on the total pressure at the hot-side inlet and the total pressure at the hot-side outlet; obtain the mass flow rate at the hot-side inlet of the test air heat exchanger (100) based on the diameter of the first pipe (1), the total pressure at the hot-side inlet, the static pressure at the hot-side inlet, and the temperature at the hot-side inlet; obtain the cold-side flow resistance on the test air heat exchanger (100) based on the total pressure at the cold-side inlet and the total pressure at the cold-side outlet; adjust the speed of the fan (11) according to... Based on the diameter of the first pipe (1), the total pressure and static pressure of the cold side inlet, and the temperature of the cold side inlet, the mass flow rate of the cold side inlet of the tested air heat exchanger (100) is obtained; based on the correspondence between multiple sets of hot side flow resistance and the mass flow rate of the hot side inlet, the fitting curve of the hot side flow resistance and the mass flow rate of the tested air heat exchanger (100) is fitted; based on the correspondence between multiple sets of cold side flow resistance and the mass flow rate of the cold side inlet, the fitting curve of the cold side flow resistance and the mass flow rate of the tested air heat exchanger (100) is fitted.

2. The low-power air heat exchanger performance test bench according to claim 1, characterized in that, The temperature measuring component also includes a second temperature sensor (1b) installed on the second pipe (2) to measure the hot edge outlet temperature and a fourth temperature sensor (1d) installed on the fourth pipe (4) to measure the cold edge outlet temperature; the control and display obtain the temperature efficiency of the tested air heat exchanger (100) based on the hot edge inlet temperature, hot edge outlet temperature, cold edge inlet temperature, and cold edge outlet temperature; the hot edge flow rate and cold edge flow rate are adjusted, and the flow rate ratio is obtained. Based on the correspondence between multiple sets of flow rate ratios and temperature efficiency, a fitting curve of the flow rate ratio and temperature efficiency of the tested air heat exchanger (100) is obtained.

3. The low-power air heat exchanger performance test bench according to claim 1, characterized in that, The second pipe (2) turns back to the third pipe (3) and is connected to the third pipe (3), and the cooler (31) is located downstream of the second pipe (2).

4. The low-power air heat exchanger performance test bench according to claim 3, characterized in that, An induced air mixer (32) is connected at the connection between the third pipe (3) and the second pipe (2).

5. The low-power air heat exchanger performance test bench according to claim 3, characterized in that, The third pipe (3) is equipped with a rectifier (33) and is located downstream of the second pipe (2).

6. The low-power air heat exchanger performance test bench according to claim 1, characterized in that, The fourth pipe (4) is rotated back to the first pipe (1). Both the fourth pipe (4) and the first pipe (1) are connected to the regenerator (41), which is located upstream of the heater (12).

7. The low-power air heat exchanger performance test bench according to claim 6, characterized in that, A rectifier (33) is provided on the fourth pipe (4).

8. The low-power air heat exchanger performance test bench according to claim 1, characterized in that, The third pipe (3) is provided with a first regulating valve (4a).

9. The low-power air heat exchanger performance test bench according to claim 1, characterized in that, The fourth pipe (4) is provided with a fourth regulating valve (4d).

10. The low-power air heat exchanger performance test bench according to claim 1, characterized in that, The second pipe (2) is connected to a sixth pipe (6), and the sixth pipe (6) is provided with a third regulating valve (4c).

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