A performance test platform for supercritical carbon dioxide printed circuit board heat exchangers

Abstract

The present invention discloses a test platform for a supercritical carbon dioxide printed circuit board type heat exchanger, comprising: a start-up circuit, the start-up circuit is used to provide a carbon dioxide fluid that meets the pressure requirements for the test platform; a hot side circuit, comprising a first stop valve, a first buffer tank, a first circulation pump, a first heater and a first pressure regulating valve group, the hot side circuit supplies the carbon dioxide fluid to flow in the part; a cold side circuit, comprising a second stop valve, a second buffer tank, a second circulation pump, a cooler and a second pressure regulating valve group, the cold side circuit supplies the carbon dioxide fluid to flow in the part; a monitoring device, used to monitor the operating parameters of the carbon dioxide flowing in the cold side circuit and the hot side circuit; a control system, the control system is connected to the monitoring device by signal, and the control system is used to control the operation of the test platform. The present invention is used to solve the problem that the current research on supercritical carbon dioxide printed circuit board type heat exchangers lacks a safe and reliable performance testing platform.

Description

Technical Field

[0001] The present application relates to the technical field of supercritical carbon dioxide printed circuit board type heat exchangers, and in particular to a testing platform for supercritical carbon dioxide printed circuit board type heat exchangers. Background Art

[0002] At present, supercritical carbon dioxide power generation systems have broad application prospects due to their high efficiency, small system size, and low noise. A key feature of the Brayton cycle used in supercritical carbon dioxide power generation systems is that a large amount of heat can be regenerated after the turbine exhaust. Therefore, the thermal efficiency of the Brayton cycle depends largely on the heat recovery efficiency of the turbine exhaust fluid. Printed circuit board heat exchangers, which have many advantages such as high temperature and high pressure resistance, low leakage, and compact structure, are widely used as regenerators in supercritical carbon dioxide power generation systems. However, since the performance research of printed circuit board heat exchangers is still at the stage of numerical simulation and theoretical analysis, there is a lack of a safe and reliable performance test platform for supercritical carbon dioxide printed circuit board heat exchangers.

[0003] The document with publication number CN110044647A discloses a supercritical carbon dioxide printed circuit board heat exchanger performance test device, which simulates the working state of the supercritical carbon dioxide printed circuit board heat exchanger by setting a hot side fluid circulation loop and a cold side fluid circulation loop respectively connected to the tested heat exchanger fluid to test the performance of the heat exchanger. However, since the test device is not provided with a carbon dioxide buffer device, the operating parameters of the carbon dioxide fluid inside it fluctuate greatly, resulting in low accuracy of the test results of the test device. At the same time, the test device lacks necessary safety protection devices. Therefore, the performance test device still has many limitations in practical applications. Summary of the invention

[0004] The purpose of the present application is to solve the above-mentioned problem that there is currently no safe and reliable supercritical carbon dioxide printed circuit board type heat exchanger performance test device. The present application provides a practical supercritical carbon dioxide printed circuit board type heat exchanger performance test platform, the supercritical carbon dioxide printed circuit board type heat exchanger includes: a body, a cold side inlet, a cold side outlet, a hot side inlet and a hot side outlet; characterized in that the performance test platform includes: a starting circuit, including a gas cylinder for providing carbon dioxide and a plunger pump for increasing the pressure of the carbon dioxide fluid, the plunger pump is located downstream of the gas cylinder; a hot side circuit, including a first stop valve, a first pressure regulating valve group for adjusting the pressure of the carbon dioxide fluid, a first buffer tank for storing the carbon dioxide fluid, a first circulation pump for providing flow power for the carbon dioxide fluid, and a first heater for increasing the temperature of the carbon dioxide fluid, the first pressure regulating valve group, the first buffer tank, the first circulation pump, the first heater, the hot side inlet and the hot side outlet are connected in sequence through pipelines to form a circulation circuit for the carbon dioxide fluid to flow inside, the plunger pump, the first stop valve and the The first buffer tank is connected in sequence through pipelines, and when the first stop valve is in an open state, the plunger pump is in fluid communication with the first buffer tank; a cold side circuit, including a second stop valve, a second pressure regulating valve group for adjusting the pressure of the carbon dioxide fluid, a second buffer tank for storing the carbon dioxide fluid, a second circulation pump for providing flow power for the carbon dioxide fluid, and a cooler for reducing the temperature of the carbon dioxide fluid, the cooler, the second pressure regulating valve group, the second buffer tank, the second circulation pump, the cold side inlet and the cold side outlet are connected in sequence through pipelines to form a circulation circuit for the carbon dioxide fluid to flow inside, the plunger pump, the second stop valve and the second buffer tank are connected in sequence through pipelines, and when the second stop valve is in an open state, the plunger pump is in fluid communication with the second buffer tank; a monitoring device, used to monitor the operating parameters of the carbon dioxide flowing in the cold side circuit and the hot side circuit, and the operating parameters at least include the carbon dioxide pressure and the carbon dioxide temperature; a control system, the control system is connected to the monitoring device by signal, and the control system is used to control the operation of the test platform.

[0005] Compared with the prior art, the above scheme has the following advantages: (1) The use of a plunger pump to increase the carbon dioxide pressure can effectively alleviate the cavitation effect of supercritical carbon dioxide coexisting with gas and liquid on the pump body, thereby increasing the service life of the pump body; (2) A buffer tank capable of storing supercritical carbon dioxide fluid is arranged upstream of the circulating pump. On the one hand, it can effectively reduce the fluctuation of the operating parameters of the carbon dioxide fluid in the circulation loop caused by the start and stop of the plunger pump, the change of the stop valve state, the start and stop of the circulating pump, etc., so as to improve the accuracy of the test results; on the other hand, it can compensate for the volume change of the carbon dioxide fluid in the circulation loop caused by the change of the operating parameters, thereby ensuring the inlet flow of the circulating pump; (3) The independently arranged starting circuit can replenish the carbon dioxide fluid to the cold side circuit and the hot side circuit without stopping the test platform, thereby improving the efficiency of the test platform.

[0006] In a preferred technical solution, the starting circuit further includes: a vaporizer located between the gas cylinder and the plunger pump, and the vaporizer is used to vaporize the liquid carbon dioxide from the gas cylinder.

[0007] In a preferred technical solution, the first and second circulating pumps are configured as variable frequency pumps capable of adjusting the fluid flow rate at their outlets. The first and second circulating pumps adopt a variable frequency design to adjust the fluid flow rate in the circulation loop, solving the problem in the prior art that the fluid pressure and fluid flow rate in the circulation loop cannot be adjusted separately.

[0008] In a preferred technical solution, the hot side loop further includes: a first vacuum pump and a first vacuum pump inlet valve located upstream of the first vacuum pump, the first vacuum pump and the first vacuum pump inlet valve are connected to the first circulation loop through a pipeline, when the first vacuum pump inlet valve is in an open state, the first vacuum pump is in fluid communication with the first circulation loop, and the first vacuum pump is used to extract the residual fluid in the first circulation loop; the cold side loop further includes: a second vacuum pump and a second vacuum pump inlet valve located upstream of the second vacuum pump, the second vacuum pump and the second vacuum pump inlet valve are connected to the second circulation loop through a pipeline, when the second vacuum pump inlet valve is in an open state, the second vacuum pump is in fluid communication with the second circulation loop, and the second vacuum pump is used to extract the residual fluid in the second circulation loop. Air has the characteristics of low heat transfer coefficient, large compression ratio and not easy to liquefy. If air is mixed into the carbon dioxide fluid in the circulation loop, on the one hand, cavitation will occur in the circulation pump, reducing the service life of the circulation pump, and on the other hand, the accuracy of the test results of the test platform will be greatly reduced, and even the "air hammer" phenomenon (a phenomenon in which air is mixed into a pressure pipe filled with incompressible fluid, causing the pipe to vibrate violently, and even damaging the pipe and equipment) will occur, causing damage to the test platform. Compared with the prior art, the additional vacuum pump and vacuum pump inlet valve can extract the residual fluid including air in the circulation loop when the test platform is started, thereby solving the above problems.

[0009] In a preferred technical solution, the cold side loop further comprises: a second heater for increasing the temperature of carbon dioxide, wherein the second heater is located between the second circulation pump and the cold side inlet and is fluidically connected to the second circulation loop.

[0010] In a preferred technical solution, the monitoring device includes: a first flow meter, a first pressure gauge, a first circulation pump thermometer, a first inlet thermometer and a first outlet thermometer arranged on the hot side loop, wherein the first flow meter, the first pressure gauge and the first circulation pump thermometer are located between the first circulation pump and the first heater, the first inlet thermometer is located between the first heater and the hot side inlet, and the first outlet thermometer is located between the hot side outlet and the pressure regulating valve group, wherein the first flow meter is configured as a mass flow meter for monitoring the mass flow of the hot side fluid; the first flow meter is arranged on the cold side The second flow meter, second pressure gauge, second circulation pump thermometer, second inlet thermometer, second outlet thermometer and cooler thermometer on the loop, the second flow meter, second pressure gauge and second circulation pump thermometer are located between the second circulation pump and the second heater, the second inlet thermometer is between the second heater and the cold side inlet, the second outlet thermometer is between the cold side outlet and the cooler, the cooler thermometer is between the cooler and the second pressure regulating valve group, wherein the second flow meter is configured as a mass flow meter for monitoring the mass flow of the cold side fluid.

[0011] In a preferred technical solution, the monitoring device further includes: a first differential pressure gauge arranged in the hot side circuit, the differential pressure gauge being used to monitor the fluid pressure difference of the carbon dioxide between the hot side inlet and the hot side outlet; and a second differential pressure gauge arranged in the cold side circuit, the differential pressure gauge being used to monitor the fluid pressure difference of the carbon dioxide between the cold side inlet and the cold side outlet.

[0012] In a preferred technical solution, the first pressure regulating valve group includes: a first pressure regulating inlet valve, a first pressure regulating valve located downstream of the first pressure regulating inlet valve, a first pressure regulating outlet valve located downstream of the first pressure regulating valve, and a first pressure regulating bypass valve, wherein the first pressure regulating valve is configured to have its valve opening controlled by a control system, and the first bypass valve has two ends, wherein the end located upstream is fluidly connected to an upstream pipeline connected to the first pressure regulating inlet valve, and the end located downstream is fluidly connected to a downstream pipeline connected to the first pressure regulating outlet valve; the second pressure regulating valve group includes: a second pressure regulating inlet valve, a second pressure regulating valve located downstream of the second pressure regulating inlet valve, a second pressure regulating outlet valve located downstream of the second pressure regulating valve, and a second pressure regulating bypass valve, wherein the second pressure regulating valve is configured to have its valve opening controlled by a control system, and the second bypass valve has two ends, wherein the end located upstream is fluidly connected to an upstream pipeline connected to the second pressure regulating inlet valve, and the end located downstream is fluidly connected to a downstream pipeline connected to the second pressure regulating outlet valve. The pressure regulating valve can adjust the fluid pressure from the circulation pump to the first pressure regulating valve in the corresponding circulation loop by adjusting its own valve opening. Since the pressure regulating valve is flushed by the fluid for a long time, it may not be closed tightly. Therefore, a pressure regulating inlet valve and a pressure regulating outlet valve are configured. When it is necessary to block the flow of fluid in the corresponding circulation pipeline, the pressure regulating inlet valve, pressure regulating valve, pressure regulating outlet valve and bypass valve are closed at the same time. When the bypass valve is used in the startup stage of the retest platform or when the pressure regulating inlet valve, pressure regulating valve and pressure regulating outlet valve fail, the fluid in the same circulation loop is removed.

[0013] In a preferred technical solution, the hot side circuit further includes: a first throttle valve and a first throttle inlet valve located upstream of the first throttle valve, the first throttle valve and the first throttle inlet valve are connected to the first circulation circuit through a pipeline, and when the first throttle inlet valve is in an open state, the first throttle valve is fluidly connected to the first circulation circuit; the cold side circuit further includes: a second throttle valve and a second throttle inlet valve located upstream of the second throttle valve, the second throttle valve and the second throttle inlet valve are connected to the second circulation circuit through a pipeline, and when the second throttle inlet valve is in an open state, the second throttle valve is fluidly connected to the second circulation circuit.

[0014] In a preferred technical solution, the first safety valve is connected to the first circulation loop fluid, and a safety pressure value is preset. When the fluid pressure inside the first circulation loop is greater than the safety pressure value preset by the first safety valve, the first safety valve opens to quickly relieve the pressure of the first circulation loop; the cold side loop also includes: a normally closed second safety valve, the second safety valve is connected to the second circulation loop fluid through a pipeline, and a safety pressure value is preset by the second safety valve. When the fluid pressure inside the second circulation loop is greater than the safety pressure value preset by the second safety valve, the second safety valve opens to quickly relieve the pressure of the second circulation loop. The safety valve is used to ensure the safe operation of the test platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a performance testing platform for a supercritical carbon dioxide printed circuit board type heat exchanger provided in an embodiment of the present application.

[0016] Figure 2 for Figure 1 A partial enlarged view of point A of the performance testing platform.

[0017] Figure 3 for Figure 1 A local enlarged view of point B of the performance testing platform.

[0018] Figure 4 for Figure 1 A local enlarged view of point C of the performance testing platform.

[0019] Figure 5 for Figure 1 Schematic diagram of the control system of the performance testing platform. DETAILED DESCRIPTION

[0020] To describe the technical content, structural features, achieved purpose and effect of the invention in detail, the technical scheme in the embodiment of the present application will be described below in conjunction with the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiment of the present application, rather than all the embodiments. In the following description, for the purpose of explanation, many specific details are set forth to provide a detailed description of various exemplary embodiments or implementations of the invention. However, various exemplary embodiments may also be implemented without these specific details or in the case of one or more equivalent arrangements. In addition, various exemplary embodiments may be different, but not necessarily exclusive. For example, without departing from the inventive concept, the specific shape, structure and characteristics of the exemplary embodiment may be used or implemented in another exemplary embodiment.

[0021] In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0022] In addition, in the present application, spatial relative terms such as "under", "below", "under", "down", "above", "up", "above", "higher", "side" (for example, as in "sidewall"), etc., are used to describe the relationship between one element and another (other) element as shown in the accompanying drawings. The spatial relative terms are intended to include different orientations of the device in use, operation and / or manufacture in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, the element described as "under" or "under" other elements or features will then be positioned as "above" the other elements or features. Therefore, the exemplary term "under" can include both the above and below orientations. In addition, the device can be positioned otherwise (for example, rotated 90 degrees or at other orientations), so the spatial relative descriptors used herein are interpreted accordingly. In the present application, "upstream" and "downstream" refer to "upstream" and "downstream" with respect to the flow direction of the fluid. For example, the word "upstream" in "a throttle inlet valve located upstream of the throttle valve" is used to indicate that the throttle inlet valve is located upstream of the throttle valve in terms of the fluid flow direction.

[0023] In this application, "normally closed" or "normally open" means that the valve is always in a closed or open state without special instructions. For example, "the cold side pressure relief valve is in a normally closed state" means that the cold side pressure relief valve is always in a closed state without special instructions.

[0024] In this application, "rapid pressure relief" means that the circulation pipeline is directly connected to the outside world, and the high-pressure fluid in the circulation pipeline is quickly discharged to the outside world without throttling or reducing pressure, thereby achieving the effect of quickly reducing the fluid pressure in the circulation pipeline. For example: "the first safety valve is opened to quickly relieve the pressure of the first circulation loop" means that when the first safety valve is opened, the first circulation loop is directly fluidically connected to the outside world, and the high-pressure fluid in the first circulation loop is directly discharged to the outside world without throttling or reducing pressure, thereby achieving a rapid reduction in the fluid pressure in the first circulation loop.

[0025] In the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0026] See also Figure 1-Figure 5 , shows a schematic diagram of a performance test platform 100 (hereinafter referred to as the test platform) for a supercritical carbon dioxide printed circuit board heat exchanger provided in an embodiment of the present application. The test platform 100 includes a start-up circuit 1, a hot side circuit 2, a cold side circuit 3, a monitoring device 4, and a control system 5. The start-up circuit 1 is used to provide carbon dioxide that meets the test pressure requirements to the hot side circuit 2, the cold side circuit 3, and the tested supercritical carbon dioxide printed circuit board heat exchanger 10 (hereinafter referred to as the heat exchanger). Figure 3 As shown, the heat exchanger 10 includes a hot side inlet 12, a hot side outlet 13, a cold side inlet 14, a cold side outlet 15 and a body 11. The body of the heat exchanger has two mutually separated hot side channels and a cold side channel (not shown in the figure) for heat exchange between two fluids, wherein the fluid entering the body 11 from the cold side inlet 14 passes through the cold side channel inside the body 11 and leaves the heat exchanger 10 from the cold side outlet 15, and the fluid entering the body 11 from the hot side inlet 12 passes through the hot side fluid channel inside the body 11 and leaves the heat exchanger 10 from the hot side outlet 13.

[0027] The starting circuit 1 includes a gas cylinder 101, a vaporizer 102 located downstream of the gas cylinder 101, and a plunger pump 103 located downstream of the vaporizer 102. The gas cylinder 101, the vaporizer 102, and the plunger pump 103 are connected by pipelines in sequence and are fluidically connected. The gas cylinder 101 is used to provide carbon dioxide to the test platform 100 and the heat exchanger 10. The vaporizer 102 is used to vaporize the liquid carbon dioxide from the gas cylinder 101. The plunger pump 103 is used to increase the pressure of the carbon dioxide fluid from the vaporizer 102. Since the carbon dioxide is in a supercritical state of gas-liquid combination when the test platform 100 is working, compared with other types of pumps, the plunger pump can not only provide a sufficiently high pressure for the carbon dioxide, but also effectively alleviate the cavitation effect of the gas-liquid coexisting carbon dioxide on the pump body, thereby increasing the life of the pump body.

[0028] The hot side loop 2 includes a pressure regulating valve group 205, a buffer tank 202, a circulation pump 203 and a heater 204 which are sequentially connected by pipeline fluid. The hot side inlet 12 of the heat exchanger 10 is in fluid communication with the heater 204 through a pipeline, and the hot side outlet 13 is in fluid communication with the pressure regulating valve group 205 through a pipeline. The pressure regulating valve group 205, the buffer tank 202, the circulation pump 203, the heater 204 and the heat exchanger 10 constitute a circulation loop 220 for carbon dioxide to circulate in the hot side loop 2. The hot side loop 2 also includes a stop valve 201 having two ends (not shown in the figure), wherein the upstream end of the stop valve 201 is in fluid communication with the plunger pump 103 through a pipeline, and the downstream end of the stop valve 201 is in fluid communication with the buffer tank 202 through a pipeline. The stop valve 201 is configured to control its valve opening by the control system 5. When the stop valve 201 is in an open state, the plunger pump 103 is in fluid communication with the buffer tank 202.

[0029] The buffer tank 202 is used to store carbon dioxide. On the one hand, the buffer tank 202 can alleviate the pressure fluctuations in the pipeline caused by the start and stop of the plunger pump 103, the stop valve 201 and the circulation pump 203 or the change of operating parameters, thereby reducing the pipeline vibration and the fluctuation of the values ​​measured by the monitoring device 3. On the other hand, the buffer tank 202 can compensate for the volume change of the carbon dioxide flowing in the hot side loop 2 caused by the temperature and pressure changes, and provide a stable inlet flow for the downstream circulation pump 203. The circulation pump 203 is used to provide flow power for the carbon dioxide in the circulation loop 220. In this example, the circulation pump 203 is configured as a variable frequency pump that can adjust its own outlet fluid flow.

[0030] The pressure regulating valve group 205 includes a pressure regulating inlet valve 2051, a pressure regulating valve 2052, a pressure regulating outlet valve 2053 and a pressure regulating bypass valve 2054. The pressure regulating bypass valve 2054 has two ends (not shown in the figure), wherein the upstream end of the pressure regulating bypass valve 2054 is in fluid communication with the upstream pipeline connected to the pressure regulating inlet valve 2051 through a pipeline, and the downstream end of the pressure regulating bypass valve 2054 is in fluid communication with the downstream pipeline connected to the pressure regulating outlet valve 2053 through a pipeline. The pressure regulating valve 2052 is configured to be able to adjust its valve opening by the control system 5. When the test platform 100 is working, the pressure regulating inlet valve 2052 and the pressure regulating outlet valve 2053 are in an open state, and the pressure regulating bypass valve 2054 is in a closed state. The control system 5 adjusts the valve opening of the pressure regulating valve 2052 to adjust the pressure of the carbon dioxide fluid in the circulation loop 220, thereby achieving the function of adjusting the fluid pressure of the hot side inlet 12 of the heat exchanger 10. Since the pressure regulating valve 2052 is flushed by the fluid for a long time, the valve core is worn and cannot be closed tightly. Therefore, when it is necessary to cut off the fluid communication before and after the pressure regulating valve group 205, it is necessary to simultaneously close the pressure regulating inlet valve 2051, the pressure regulating valve 2052, the pressure regulating outlet valve 2053 and the pressure regulating bypass valve 2054. The bypass valve 2054 is used to circulate the fluid upstream and downstream of the pressure regulating valve group 205 when the test platform 100 is started or any of the pressure regulating inlet valve 2051, the pressure regulating valve 2052 and the pressure regulating outlet valve 2054 fails.

[0031] The heater 204 is used to heat the carbon dioxide flowing in the circulation loop 220 so that the fluid temperature at the heated side inlet 12 reaches the test requirement.

[0032] The hot side loop 2 is also provided with a throttle valve 207, a vacuum pump 210 and a safety valve 208. The throttle valve 207 and the vacuum pump 208 are connected to the circulation loop 220 through the normally closed throttle inlet valve 206 and the vacuum pump inlet valve 209 respectively. The vacuum pump 210 is used to extract the residual fluid in the hot side loop 2 when the test platform 100 is started, and the throttle valve 207 is used to discharge the residual fluid in the hot side loop 2 after the test platform 100 ends the test and to ensure that the fluid pressure in the hot side loop 2 is equal to the atmospheric pressure before the vacuum pump 100 is started. When the throttle valve 207 is opened, the high-pressure fluid in the circulation loop 220 is throttled and depressurized by the throttle valve 207 and then discharged to the outside to avoid the high-pressure fluid from directly spraying to the equipment or personnel outside, thereby improving the safety of the test platform 100. The safety valve 208 is connected to the circulation loop 220 through a pipeline and is in a normally closed state. The safety valve 208 is preset with a safety pressure value. When the test platform 100 needs to be shut down urgently or the fluid pressure in the circulation loop 220 is greater than the safety pressure value of the safety valve 208, the safety valve 208 opens to quickly release the pressure in the circulation loop 220.

[0033] The measurement and control device 4 includes a flow meter 401, a pressure gauge 402, a circulating pump thermometer 403, an inlet thermometer 404, an outlet thermometer 405 and a differential pressure gauge 406 located on the hot side loop 2. The flow meter 401, the pressure gauge 402 and the circulating pump thermometer 403 are located between the circulating pump 203 and the heater 204, and are used to monitor the flow rate, temperature and pressure of the outlet fluid of the circulating pump 203 respectively. In this example, the flow meter 401 is configured as a mass flow meter for monitoring the mass flow rate of the hot side fluid to improve the accuracy of the test result (when the carbon dioxide fluid passes through the heater 204, the volume expands due to heat, which causes the volume flow rate to change). The inlet thermometer 404 is located between the heater 204 and the heat exchanger 10, and is used to monitor the temperature of the hot side inlet 12 fluid of the heat exchanger 10. The outlet thermometer 405 is located between the heat exchanger 10 and the pressure regulating valve group 205, and is used to monitor the hot side outlet fluid temperature of the heat exchanger 10. The differential pressure gauge 406 has two ends (not shown in the figure), one end of the differential pressure gauge 406 is connected to the hot side inlet 12 fluid through a pipeline, and the other end is connected to the hot side outlet 13 fluid through a pipeline. The differential pressure gauge 406 is used to monitor the pressure difference between the internal fluid pressure of the hot side inlet 12 and the hot side outlet 13.

[0034] The cold side loop 3 includes a cooler 311, a pressure regulating valve group 305, a buffer tank 302, a circulation pump 303 and a heater 304 which are sequentially connected by pipeline fluid. The cold side inlet 14 of the heat exchanger 10 is in fluid communication with the heater 304 through a pipeline, and the cold side outlet 15 is in fluid communication with the cooler 311 through a pipeline. The cooler 311, the pressure regulating valve group 305, the buffer tank 302, the circulation pump 303, the heater 304 and the heat exchanger 10 constitute a circulation loop 320 for carbon dioxide to circulate in the cold side loop 3. The cold side loop 3 also includes a stop valve 301 having two ends (not shown in the figure), wherein the upstream end of the stop valve 301 is in fluid communication with the plunger pump 103 through a pipeline, and the downstream end of the stop valve 301 is in fluid communication with the buffer tank 302 through a pipeline. The stop valve 301 is configured to control its valve opening by the control system 5. When the stop valve 301 is in an open state, the plunger pump 103 is in fluid communication with the buffer tank 302.

[0035] The buffer tank 302 is used to store carbon dioxide. On the one hand, the buffer tank 302 can alleviate the pressure fluctuations in the pipeline caused by the start and stop of the plunger pump 103, the stop valve 301 and the circulation pump 303 or the change of operating parameters, thereby reducing the pipeline vibration and the fluctuation of the values ​​measured by the monitoring device 3. On the other hand, the buffer tank 302 can compensate for the volume change of the carbon dioxide flowing in the cold side loop 3 due to temperature and pressure changes, and provide a stable inlet flow for the downstream circulation pump 303. The circulation pump 303 is used to provide flow power for the carbon dioxide in the circulation loop 320. In this example, the circulation pump 303 is configured as a variable frequency pump that can adjust its own outlet fluid flow.

[0036] The pressure regulating valve group 305 includes a pressure regulating inlet valve 3051, a pressure regulating valve 3052, a pressure regulating outlet valve 3053 and a pressure regulating bypass valve 3054. The pressure regulating bypass valve 3054 has two ends (not shown in the figure), wherein the upstream end of the pressure regulating bypass valve 3054 is in fluid communication with the upstream pipeline connected to the pressure regulating inlet valve 3051 through a pipeline, and the downstream end of the pressure regulating bypass valve 3054 is in fluid communication with the downstream pipeline connected to the pressure regulating outlet valve 3053 through a pipeline. The pressure regulating valve 3052 is configured to be able to adjust its valve opening by the control system 5. When the test platform 100 is working, the pressure regulating inlet valve 3052 and the pressure regulating outlet valve 3053 are in an open state, and the pressure regulating bypass valve 3054 is in a closed state. The control system 5 adjusts the valve opening of the pressure regulating valve 3052 to adjust the pressure of the carbon dioxide fluid in the circulation loop 320, thereby achieving the function of adjusting the fluid pressure of the cold side inlet 14 of the heat exchanger 10. Since the pressure regulating valve 3052 is flushed by the fluid for a long time, the valve core is worn and cannot be closed tightly. Therefore, when it is necessary to block the fluid communication before and after the pressure regulating valve group 305, it is necessary to simultaneously close the pressure regulating inlet valve 3051, the pressure regulating valve 3052, the pressure regulating outlet valve 3053 and the pressure regulating bypass valve 3054. The bypass valve 3054 is used to circulate the fluid upstream and downstream of the pressure regulating valve group 305 when the test platform 100 is started or any of the pressure regulating inlet valve 3051, the pressure regulating valve 3052 and the pressure regulating outlet valve 3054 fails.

[0037] The cooler 311 is used to cool the temperature of the carbon dioxide fluid flowing out of the cold side outlet 15 so that the carbon dioxide fluid in the cold side loop 3 can be circulated. The heater 304 is used to heat the carbon dioxide flowing in the circulation loop 320 so that the fluid temperature of the cold side inlet 14 reaches the test requirements.

[0038] The cold side loop 3 is also provided with a throttle valve 307, a vacuum pump 210 and a safety valve 308. The throttle valve 307 and the vacuum pump 308 are connected to the circulation loop 320 through the normally closed throttle inlet valve 306 and the vacuum pump inlet valve 309 respectively. The vacuum pump 210 is used to extract the residual fluid in the cold side loop 3 when the test platform 100 is started, and the throttle valve 307 is used to discharge the residual fluid in the cold side loop 3 after the test platform 100 ends the test and to ensure that the fluid pressure in the cold side loop 3 is equal to the atmospheric pressure before the vacuum pump 100 is started. When the throttle valve 307 is opened, the high-pressure fluid in the circulation loop 320 is throttled and depressurized by the throttle valve 307 and then discharged to the outside to avoid the high-pressure fluid from directly spraying to the equipment or personnel outside, thereby improving the safety of the test platform 100. The safety valve 308 is connected to the circulation loop 320 through a pipeline, and the safety valve 308 is in a normally closed state. The safety valve 308 is preset with a safety pressure value. When the test platform 100 needs to be shut down urgently or the fluid pressure in the circulation loop 320 is greater than the safety pressure value of the safety valve 308, the safety valve 308 opens to quickly release the pressure in the circulation loop 320.

[0039] The measurement and control device 4 includes a flow meter 411, a pressure gauge 412, a circulating pump thermometer 413, an inlet thermometer 414, an outlet thermometer 415, a differential pressure gauge 416 and a cooler thermometer 417 located on the cold side loop 3. The flow meter 411, the pressure gauge 412 and the circulating pump thermometer 413 are located between the circulating pump 303 and the heater 304, and are used to monitor the flow rate, temperature and pressure of the outlet fluid of the circulating pump 303 respectively. In this example, the flow meter 411 is configured as a mass flow meter for monitoring the mass flow rate of the cold side fluid to improve the accuracy of the test result (when the carbon dioxide fluid passes through the heater 304, the volumetric expansion due to heating will cause the volume flow rate to change). The inlet thermometer 414 is located between the heater 304 and the heat exchanger 10, and is used to monitor the fluid temperature of the cold side inlet 14 of the heat exchanger 10. The outlet thermometer 415 is located between the heat exchanger 10 and the cooler 11, and is used to monitor the outlet fluid temperature of the cold side of the heat exchanger 10. The cooler thermometer 417 is located between the cooler 311 and the pressure regulating valve group 305, and is used to monitor the outlet fluid temperature of the cooler 311. The differential pressure gauge 416 has two ends (not shown in the figure), one end of the differential pressure gauge 416 is connected to the cold side inlet 14 fluid through a pipeline and the other end is connected to the cold side outlet 15 fluid through a pipeline. The differential pressure gauge 416 is used to monitor the pressure difference between the cold side inlet and the cold side outlet.

[0040] See also Figure 5, shows the control system 5 of the test platform. On the one hand, the control system 5 is connected to the monitoring device 4 by signal so as to receive the test platform operating parameters measured by the monitoring device 4. On the other hand, the control system 5 is connected to the various devices arranged on the starting loop 1, the hot side loop 2 and the cold side loop 3 by signal so as to control the operating status of the starting loop 1, the cold side loop 2 and the hot side loop 3 and adjust the operating parameters. Several interlocking protection mechanisms are pre-stored on the control system 5, and the interlocking protection mechanisms are used to protect the various devices connected to the control system 5 by signal and to protect the safe operation of the test platform 100. In addition, the control system 5 also has an automatic start function, an automatic shutdown function, an emergency shutdown function, etc., which will not be elaborated here.

[0041] Please continue reading Figure 1 , the working principle of the test platform 100 is now described. When the test platform 100 is started, the throttle valve 207, the throttle valve 307, the throttle inlet valve 206 and the throttle inlet valve 306 are opened to ensure that the fluid pressure in the cold side loop 3 and the side loop 2 is equal to the atmospheric pressure. Thereafter, the throttle valve 207, the throttle valve 307, the throttle inlet valve 206 and the throttle inlet valve 306 are closed, and the vacuum pump 210 and the vacuum pump 310 are turned on. When the inlet pressure of the vacuum pump 210 is lower than the interlocking protection starting pressure of the vacuum pump inlet valve 209 preset in the control system 5, the control system 5 is linked to open the vacuum pump inlet valve 209, the vacuum pump 210 is fluidly connected with the circulation pipeline 220 and the hot side loop 2 is evacuated; when the inlet pressure of the vacuum pump 310 is lower than the interlocking protection starting pressure of the vacuum pump inlet valve 309 preset in the control system 5, the control system 5 is linked to open the vacuum pump inlet valve 309, the vacuum pump 310 is fluidly connected with the circulation pipeline 320 and the cold side loop 3 is evacuated. When the vacuum pump 210 reduces the fluid pressure in the hot side loop 2 to the corresponding pressure value preset by the control system 5, the control system 5 closes the vacuum pump inlet valve 209, and the vacuum pump 210 automatically shuts down under the action of the interlocking protection; when the vacuum pump 310 reduces the fluid pressure in the cold side loop 3 to the corresponding pressure value preset by the control system 5, the control system 5 closes the vacuum pump inlet valve 309, and the vacuum pump 310 automatically shuts down under the action of the interlocking protection.

[0042] After confirming that the fluid pressure in the cold side loop 2 and the hot side loop 3 is reduced to the set value and the vacuum pump inlet valve 209 and the vacuum pump inlet valve 309 are closed, and the vacuum pump 210 and the vacuum pump 310 are stopped. Manually open the gas cylinder 101, and the carbon dioxide gas in the gas cylinder 101 enters the vaporizer 102 through the pipeline. Under the action of the vaporizer 102, the liquid carbon dioxide from the gas cylinder 101 is gasified. Thereafter, the stop valve 201 and the stop valve 301 are opened, and the start loop 1 is fluidly connected to the hot side loop 2 and the cold side loop 3. The plunger pump 103 is started to pressurize the carbon dioxide and transport it to the hot side loop 2 and the cold side loop 3.

[0043] The pressure gauge 401 and the thermometer 402 transmit the measured fluid pressure and fluid temperature in the hot side loop 2 to the control system 5. The control system 5 calculates the corresponding pressure of the fluid when it is at the test temperature based on the received fluid temperature and fluid pressure. When the calculated corresponding pressure reaches the required test pressure, the stop valve 201 is closed. After the stop valve 201 is closed, the fluid connection between the start loop 1 and the hot side loop 2 is cut off. In this process, since the pressure in the hot side loop 2 is constantly changing, in order to prevent the pressure regulating valve 2052 controlled by the control system 5 from frequently operating and causing frequent fluctuations in the pressure in the hot side loop 2, or even the occurrence of malfunction of the equipment under the action of interlocking protection, the pressure regulating inlet valve 2051, the pressure regulating valve 2052 and the pressure regulating outlet valve 2053 are closed, and the pressure regulating bypass valve 2054 is opened to allow the fluid to flow through the pipeline connected to the pressure regulating bypass valve 2054. After the pressure in the hot side circuit 2 reaches the pressure required for the test, the pressure regulating inlet valve 2051, the pressure regulating valve 2052 and the pressure regulating outlet valve 2053 are opened. After the pressure regulating valve 2052 is stabilized at a certain opening, the pressure regulating bypass valve 2054 is closed to complete the switching of the fluid path from the pressure regulating bypass valve 2054 to the pressure regulating valve 2052.

[0044] The pressure gauge 411 and the thermometer 412 transmit the measured fluid pressure and fluid temperature in the cold side loop 3 to the control system 5. The control system 5 calculates the corresponding pressure of the fluid when it is at the test temperature based on the received fluid temperature and fluid pressure. When the calculated corresponding pressure reaches the required test pressure, the stop valve 301 is closed. After the stop valve 301 is closed, the fluid connection between the start loop 1 and the hot side loop 3 is cut off. In this process, since the pressure in the cold side loop 3 is constantly changing, in order to prevent the pressure regulating valve 3052 controlled by the control system 5 from frequently operating and causing the pressure in the cold side loop 3 to frequently fluctuate or even cause the equipment to malfunction under the action of interlocking protection, the pressure regulating inlet valve 3051, the pressure regulating valve 3052 and the pressure regulating outlet valve 3053 are closed, and the pressure regulating bypass valve 3054 is opened to allow the fluid to flow through the pipeline connected to the pressure regulating bypass valve 3054. After the pressure in the cold side loop 3 reaches the required pressure for the test, the pressure regulating inlet valve 3051, the pressure regulating valve 3052 and the pressure regulating outlet valve 3053 are opened. After the pressure regulating valve 3052 is stabilized at a certain opening, the pressure regulating bypass valve 3054 is closed to complete the switching of the fluid path from the pressure regulating bypass valve 3054 to the pressure regulating valve 3052 .

[0045] After the stop valve 201 and the stop valve 301 are closed, the plunger pump 103 automatically trips under the action of the interlocking protection and stops running. Then the cold side circulation pump 203 and the circulation 204 are turned on. The flow meter 201 sends the measured outlet flow of the circulation pump 203 to the control system 5, and the control system 5 adjusts the frequency of the variable frequency circulation pump 203 based on the received flow value to control the fluid flow of the hot side inlet 12 of the heat exchanger 10; the flow meter 301 sends the measured outlet flow of the circulation pump 303 to the control system 5, and the control system 5 adjusts the frequency of the variable frequency circulation pump 303 based on the received flow value to control the fluid flow of the cold side inlet 15 of the heat exchanger 10.

[0046] After the outlet pressure of the circulating pump 203 is stabilized, the heater 204 is started. The inlet thermometer 404 sends the measured fluid temperature of the hot side inlet 12 to the control system 5, and the control system 5 controls the heater 204 based on the obtained temperature value so that the fluid temperature at the hot side inlet 12 reaches the test requirement value.

[0047] After the outlet pressure of the circulating pump 303 is stabilized, the heater 304 and the cooler 311 are started. The inlet thermometer 414 sends the measured temperature of the fluid at the cold side inlet 14 to the control system 5, and the control system 5 controls the cold side heater 304 based on the obtained temperature value, so that the fluid temperature at the cold side inlet 14 reaches the test required value. The cooler thermometer 417 sends the measured temperature of the fluid at the outlet of the cooler 311 to the control system 5, and the control system 5 controls the cooling water flow of the cooler 311 based on the obtained temperature value, so that the carbon dioxide temperature at the outlet of the cooler 311 reaches the required value.

[0048] When the operating parameters of the fluid in the hot side loop 2 and the cold side loop 3 are stabilized at the values ​​required by the test, the control system 5 records the operating parameters of the fluid in the hot side loop 2, the cold side loop 3 and the heat exchanger 10, and completes a test. After completing the heat exchange performance tests of several heat exchangers 10 under different working conditions, the control system 5 draws the heat exchange performance curve of the heat exchanger 10 to complete the test.

[0049] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and the scope of protection required by the present invention is determined by the attached claims, description and their equivalents.

Claims

1. A test platform (100) for a supercritical carbon dioxide printed circuit board type heat exchanger, the carbon dioxide printed circuit board type heat exchanger (10) comprising: A main body (11), a hot side inlet (12), a hot side outlet (13), a cold side inlet (14) and a cold side outlet (15); characterized in that the test platform (100) of the supercritical carbon dioxide printed circuit board type heat exchanger comprises: A starting circuit (1) comprising a gas cylinder (101) for providing carbon dioxide and a plunger pump (103) for increasing the pressure of the carbon dioxide fluid, wherein the plunger pump (103) is located downstream of the gas cylinder (101); The hot side loop (2) comprises a first stop valve (201), a first buffer tank (202) for storing carbon dioxide fluid, a first circulation pump (203) for providing flow power for the carbon dioxide fluid, a first heater (204) for increasing the temperature of the carbon dioxide fluid, and a first pressure regulating valve group (205) for regulating the pressure of the carbon dioxide fluid. The first buffer tank (202), the first circulation pump (203), the first heater (204), the hot side inlet (12), the hot side outlet (13), and the first pressure regulating valve group (205) are sequentially connected by pipelines to form a first circulation loop (220) for the carbon dioxide fluid to flow inside. The plunger pump (103), the first stop valve (201), and the first buffer tank (202) are sequentially connected by pipelines. When the first stop valve (201) is in an open state, the plunger pump (103) is in fluid communication with the first buffer tank (202); A cold side circuit (3), comprising a second stop valve (301), a second pressure regulating valve group (305) for regulating the pressure of a carbon dioxide fluid, a second buffer tank (302) for storing the carbon dioxide fluid, a second circulation pump (303) for providing flow power for the carbon dioxide fluid, and a cooler (311) for reducing the temperature of the carbon dioxide fluid, wherein the cooler (311), the second pressure regulating valve group (305), the second buffer tank (302), the second circulation pump (303), the cold side inlet (14), and the cold side outlet (15) are sequentially connected by pipelines to form a second circulation circuit (320) for the carbon dioxide fluid to flow inside, and the plunger pump (103), the second stop valve (301), and the second buffer tank (302) are sequentially connected by pipelines, and when the second stop valve (301) is in an open state, the plunger pump (103) is in fluid communication with the second buffer tank (302); A monitoring device (4) for monitoring operating parameters of the carbon dioxide flowing in the cold side loop (3) and the hot side loop (2), wherein the operating parameters at least include carbon dioxide pressure and carbon dioxide temperature; A control system (5), the control system (5) being signal-connected to the monitoring device (4), and the control system being used to control the operation of the test platform (100).

2. The test platform for supercritical carbon dioxide printed circuit board type heat exchanger according to claim 1, characterized in that: The starting circuit (1) further comprises: a vaporizer (102) located between the gas cylinder (101) and the plunger pump (103), wherein the vaporizer (102) is used to vaporize the liquid carbon dioxide from the gas cylinder (101).

3. The test platform for supercritical carbon dioxide printed circuit board heat exchanger according to claim 1, characterized in that: The first circulation pump (203) and the second circulation pump (303) are configured as variable frequency pumps capable of adjusting the flow rate of the fluid at their outlets.

4. The test platform for a supercritical carbon dioxide printed circuit board type heat exchanger according to claim 1, characterized in that: The hot side loop (2) further comprises: a first vacuum pump (210) and a first vacuum pump inlet valve (209) located upstream of the first vacuum pump (210); the first vacuum pump (210) and the first vacuum pump inlet valve (209) are connected to the first circulation loop (220) via a pipeline; when the first vacuum pump inlet valve (209) is in an open state, the first vacuum pump (210) is in fluid communication with the first circulation loop (220); the first vacuum pump (210) is used to extract residual fluid in the first circulation loop (220); The cold side loop also includes: a second vacuum pump (310) and a second vacuum pump inlet valve (309) located upstream of the second vacuum pump (310); the second vacuum pump (310) and the second vacuum pump inlet valve (309) are connected to the second circulation loop (320) via a pipeline; when the second vacuum pump inlet valve (309) is in an open state, the second vacuum pump (310) is fluidically connected to the second circulation loop (320); the second vacuum pump (310) is used to extract residual fluid in the second circulation loop (320).

5. The test platform for supercritical carbon dioxide printed circuit board type heat exchanger according to claim 1, characterized in that: The cold side loop (3) further comprises: a second heater (304) for increasing the temperature of carbon dioxide, wherein the second heater (304) is located between the second circulation pump (303) and the cold side inlet (14) and is fluidically connected to the second circulation loop (320).

6. The test platform for supercritical carbon dioxide printed circuit board heat exchanger according to claim 5, characterized in that: The monitoring device (4) comprises: a first flow meter (401), a first pressure gauge (402), a first circulation pump thermometer (403), a first inlet thermometer (404) and a first outlet thermometer (405) arranged on the hot side loop (2), wherein the first flow meter (401), the first pressure gauge (402) and the first circulation pump thermometer (403) are located between the first circulation pump (203) and the first heater (204), the first inlet thermometer (404) is located between the first heater (204) and the hot side inlet (12), and the first outlet thermometer (405) is located between the hot side outlet (13) and the pressure regulating valve group (205), wherein the first flow meter (401) is configured as a mass flow meter for monitoring the mass flow of the hot side fluid; A second flow meter (411), a second pressure gauge (412), a second circulation pump thermometer (413), a second inlet thermometer (414), a second outlet thermometer (415) and a cooler thermometer (417) are arranged on the cold side circuit (3); the second flow meter (411), the second pressure gauge (412) and the second circulation pump thermometer (413) are located between the second circulation pump (303) and the second heater (304); the second inlet thermometer (414) is located between the second heater (304) and the cold side inlet (14); the second outlet thermometer (415) is located between the cold side outlet (15) and the cooler (311); the cooler thermometer (417) is located between the cooler (311) and the second pressure regulating valve group (305); wherein the second flow meter (411) is configured as a mass flow meter for monitoring the mass flow of the cold side fluid.

7. The test platform for supercritical carbon dioxide printed circuit board heat exchanger according to claim 6, characterized in that: The monitoring device (4) further comprises: A first differential pressure gauge (406) is arranged in the hot side circuit (2), and the first differential pressure gauge (406) is used to monitor the fluid pressure difference of carbon dioxide inside the hot side inlet (12) and the hot side outlet (13); A second differential pressure gauge (416) is provided in the cold side circuit (3), and the second differential pressure gauge (416) is used to monitor the fluid pressure difference of carbon dioxide inside the cold side inlet (14) and the cold side outlet (15).

8. The test platform for supercritical carbon dioxide printed circuit board type heat exchanger according to claim 1, characterized in that: The first pressure regulating valve group (205) comprises: a first pressure regulating inlet valve (2051), a first pressure regulating valve (2052) located downstream of the first pressure regulating inlet valve (2051), a first pressure regulating outlet valve (2053) located downstream of the first pressure regulating valve (2052), and a first pressure regulating bypass valve (2054), wherein the first pressure regulating valve (2052) is configured to have its valve opening controlled by a control system (5), and the first pressure regulating bypass valve (2054) has two ends, wherein the end located upstream is in fluid communication with an upstream pipeline connected to the first pressure regulating inlet valve (2051), and the end located downstream is in fluid communication with a downstream pipeline connected to the first pressure regulating outlet valve (2053); The second pressure regulating valve group (305) comprises: a second pressure regulating inlet valve (3051), a second pressure regulating valve (3052) located downstream of the second pressure regulating inlet valve (3051), a second pressure regulating outlet valve (3053) located downstream of the second pressure regulating valve (3052), and a second pressure regulating bypass valve (3054), wherein the second pressure regulating valve (3052) is configured to have its valve opening controlled by a control system (5), and the second pressure regulating bypass valve (3054) has two ends, wherein the end located upstream is in fluid communication with an upstream pipeline connected to the second pressure regulating inlet valve (3051), and the end located downstream is in fluid communication with a downstream pipeline connected to the second pressure regulating outlet valve (3053).

9. The test platform for supercritical carbon dioxide printed circuit board type heat exchanger according to claim 1, characterized in that: The hot side loop (2) further comprises: a first throttle valve (207) and a first throttle inlet valve (206) located upstream of the first throttle valve (207), wherein the first throttle valve (207) and the first throttle inlet valve (206) are connected to the first circulation loop (220) via a pipeline, and when the first throttle inlet valve (206) is in an open state, the first throttle valve (207) is in fluid communication with the first circulation loop (220); The cold side circuit (3) further includes: a second throttle valve (307) and a second throttle inlet valve (306) located upstream of the second throttle valve (307); the second throttle valve (307) and the second throttle inlet valve (306) are connected to the second circulation circuit (320) via a pipeline; when the second throttle inlet valve (306) is in an open state, the second throttle valve (307) is fluidically connected to the second circulation circuit (320).

10. The test platform (100) of a supercritical carbon dioxide printed circuit board type heat exchanger according to claim 1, characterized in that: The hot side loop (2) further comprises: a normally closed first safety valve (208), the first safety valve (208) being in fluid communication with the first circulation loop (220) through a pipeline, the first safety valve (208) being preset with a safety pressure value, and when the fluid pressure inside the first circulation loop (220) is greater than the safety pressure value preset by the first safety valve (208), the first safety valve (208) opens to quickly relieve pressure in the first circulation loop (220); The cold side circuit (3) further comprises: a normally closed second safety valve (308), wherein the second safety valve (308) is connected to the fluid of the second circulation circuit (320) through a pipeline, and the second safety valve (308) is preset with a safety pressure value. When the fluid pressure inside the second circulation circuit (320) is greater than the safety pressure value preset by the second safety valve (308), the second safety valve (308) opens to quickly relieve the pressure of the second circulation circuit (320).

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