Magnetic refrigerator power test apparatus and method

Abstract

The application discloses a kind of magnetic refrigerator refrigeration power testing device and method provided by the application.A magnetic refrigerator includes a pair of magnetic regenerator modules, and the testing device includes: a heating container having a heat exchange fluid inlet and a heat exchange fluid outlet, and a heater for heating the heat exchange fluid flowing through the heating container;A pipe network is respectively connected to the cold end of the pair of magnetic regenerator modules and the heat exchange fluid inlet and outlet of the heating container, and a valve structure is provided on the pipe network to control the flow direction of the heat exchange fluid in the pipe network to remain: from the cold end of any one magnetic regenerator module to the heat exchange fluid inlet of the heating container, and from the heat exchange fluid outlet of the heating container to the cold end of the other magnetic regenerator module;Multiple temperature sensors.The device can improve testing accuracy.

Description

Technical Field

[0001] This invention relates to the field of magnetic refrigeration technology, and specifically to a magnetic refrigeration mechanism refrigeration power testing device and method. Background Technology

[0002] This section is intended to provide background or context for the embodiments set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section.

[0003] Magnetic refrigeration is a solid-state refrigeration technology that promises to replace traditional gas compression refrigeration. It utilizes the magnetocaloric effect of materials to achieve cooling. The magnetocaloric material, shaped into a specific form, is called the magnetocaloric working fluid. Heat exchange is typically achieved between the working fluid and a heat exchange fluid. Magnetic refrigerators usually employ Active Regenerative Thermal (AMR) technology to increase the cooling temperature range. The regenerator is filled with the magnetocaloric working fluid, through which the heat exchange fluid flows. When the regenerator is demagnetized, the heat exchange fluid flows in the forward direction; when the regenerator is magnetized, the heat exchange fluid flows in the reverse direction; and during magnetization and demagnetization, the heat exchange fluid remains stationary. Thus, within one AMR cycle, the regenerator undergoes four processes: cold blowing-transition-hot blowing-transition. During these four processes, the heat exchange fluid simultaneously undergoes four processes: forward flow-stillness-reverse flow-stillness. This repeated magnetization / demagnetization of the working fluid, combined with the reciprocating flow of the heat exchange fluid, gradually establishes a temperature gradient across the regenerator, forming the cold and hot ends of the regenerator. In magnetic refrigerators, two or more regenerators are typically designed. Taking two regenerators as an example, when one regenerator is magnetized, the other is demagnetized, and vice versa. The heat exchange fluid flows back and forth in accordance with the magnetization / demagnetization program of the regenerators, forming the high-temperature and low-temperature ends of the regenerators. The two cold ends of a pair of regenerators are connected to the two ends of the cold-end heat exchanger, forming a closed loop. The heat exchange fluid also flows periodically back and forth in the cold-end heat exchanger, carrying away the heat from the cold-end load and achieving refrigeration.

[0004] This reciprocating fluid flow pattern has a dead zone volume, making it difficult to calculate the cooling power of the magnetic refrigeration mechanism. Summary of the Invention

[0005] This invention provides a device and method for testing the cooling power of a magnetic refrigeration mechanism.

[0006] This invention adopts the following technical solution: a magnetic refrigeration power testing device, wherein the magnetic refrigeration machine includes paired magnetic regenerator modules, and the testing device includes:

[0007] A heating container having a heat exchange fluid inlet and a heat exchange fluid outlet, and a heater for heating the heat exchange fluid flowing through the heating container;

[0008] The pipeline network is connected to the cold ends of the paired magnetic regenerator modules and the heat exchange fluid inlet and outlet of the heating container. The pipeline network is equipped with a valve structure to control the flow direction of the heat exchange fluid in the pipeline network to be: from the cold end of any magnetic regenerator module to the heat exchange fluid inlet of the heating container, and from the heat exchange fluid outlet of the heating container to the cold end of the other magnetic regenerator module.

[0009] Multiple temperature sensors are used to measure the heat exchange fluid temperature at the hot and cold ends of at least one of the paired magnetic regenerator modules, as well as the heat exchange fluid temperature at the heating container.

[0010] In some embodiments, the paired magnetic regenerator modules are a first magnetic regenerator module and a second magnetic regenerator module, and the valve structure includes: a first check valve, a second check valve, a third check valve and a fourth check valve;

[0011] The inlet of the first one-way valve and the outlet of the third one-way valve are both connected to the cold end of the first magnetic regenerator module. The inlet of the second one-way valve and the outlet of the fourth one-way valve are both connected to the cold end of the second magnetic regenerator module. The outlets of the first one-way valve and the second one-way valve are both connected to the heat exchange fluid inlet of the heating container. The inlets of the third one-way valve and the fourth one-way valve are both connected to the heat exchange fluid outlet of the heating container.

[0012] In some embodiments, the plurality of temperature sensors include:

[0013] The first temperature sensor is used to measure the temperature of the heat exchange fluid at the hot end of the first magnetic regenerator module.

[0014] The second temperature sensor is used to measure the temperature of the heat exchange fluid at the hot end of the second magnetic regenerator module.

[0015] The third temperature sensor is used to measure the temperature of the cold-end heat exchange fluid of the first magnetic regenerator module.

[0016] The fourth temperature sensor is used to measure the temperature of the cold-end heat exchange fluid of the second magnetic regenerator module.

[0017] The fifth temperature sensor is used to measure the temperature of the heat exchange fluid at the inlet of the heating container;

[0018] The sixth temperature sensor is used to measure the temperature of the heat exchange fluid at the outlet of the heating container.

[0019] In some embodiments, the paired magnetic regenerator modules have equal cooling power.

[0020] In some embodiments, the paired magnetic regenerator modules each have one or more active magnetic regenerators that are connected to each other.

[0021] In some embodiments, the hot-end temperatures of the paired magnetic regenerator modules are set to remain constant and equal.

[0022] The present invention adopts the following technical solution: a test method for the aforementioned magnetic refrigeration power test device, comprising:

[0023] With the hot end temperatures of the paired magnetic regenerator modules kept stable and equal, the heating power of the heaters was kept at different constant values, and the cold end temperature and hot end temperature of any one magnetic regenerator module were measured over time.

[0024] When the cold end temperature and hot end temperature of any one of the magnetic regenerator modules tend to be equal as time increases, the corresponding heating power is determined as the maximum cooling power across the zero temperature span.

[0025] In some embodiments, the testing method specifically includes:

[0026] Keeping the heating power of the heater at different initial constant values, measure the cold end temperature and hot end temperature of any magnetic regenerator module over time.

[0027] The heating power with the lowest cold-end temperature stability value among the test results where the cold-end temperature stability value is greater than the hot-end temperature stability value is selected as the first heating power, and the heating power with the highest cold-end temperature stability value among the test results where the cold-end temperature stability value is less than the hot-end temperature stability value is selected as the second heating power. The maximum cooling power of the zero-temperature span is determined based on the first heating power, the second heating power, the corresponding cold-end temperature stability values, and the hot-end temperature stability value.

[0028] In some embodiments, determining the maximum cooling power across the zero temperature span based on the first heating power and the second heating power, the corresponding stable cold-end temperature values, and the stable hot-end temperature values ​​includes:

[0029] The predicted value of the maximum cooling power across the zero temperature span is determined by an interpolation method. The cold end stable temperature is set to vary linearly with the heating power between the first heating power and the second heating power. The heating power when the cold end stable temperature is equal to the hot end stable temperature is calculated as the predicted value of the maximum cooling power across the zero temperature span.

[0030] The heating power of the heater is set to the predicted value. When the difference between the stable cold end temperature value and the stable hot end temperature value of any magnetic regenerator module is within the preset error range, the predicted value is used as the measured value of the maximum cooling power at zero temperature span.

[0031] In some embodiments, when the heating power of the heater is set to the predicted value, if the difference between the stable cold-end temperature value and the stable hot-end temperature value of any magnetic regenerator module exceeds a preset error range, the stable cold-end temperature value corresponding to the first heating power and the second heating power is replaced with the predicted value, whichever has the same polarity as the predicted value relative to the stable hot-end temperature value. The prediction value of the maximum cooling power across the zero temperature span is then determined by an extrapolation method. This process is repeated until the heating power of the heater is set to the predicted value and the difference between the stable cold-end temperature value and the stable hot-end temperature value of any magnetic regenerator module is within a preset error range.

[0032] When heat exchange fluid flows inside the regenerator, the fluid exiting the regenerator passes through a one-way valve, maintaining unidirectional flow, and then passes through the heating container, where heat exchange occurs. The fluid that flows back and forth inside the regenerator becomes unidirectional after exiting through the one-way valve, reducing dead volume, facilitating the calculation of the magnetic refrigeration system's cooling power, and resulting in more accurate calculations.

[0033] Note: Dead volume has two meanings. First, it refers to fluid that does not flow in certain corner areas. Second, it refers to fluid that does not contribute to heat exchange. This patent mainly refers to the second meaning. In a preferred embodiment of the invention, the one-way valve is placed as close as possible to the cold end outlet of the regenerator. This minimizes the dead volume in the second sense, allowing for full utilization of the cold heat exchange fluid flowing out of the regenerator for heat exchange. Attached Figure Description

[0034] Figure 1 This is a structural diagram of the magnetic refrigerator and its cooling power testing device according to an embodiment of the present invention.

[0035] Figure 2a This is a graph showing the change of the magnetic field over time within the magnetic regenerator module of the magnetic refrigerator according to an embodiment of the present invention.

[0036] Figure 2b This is a schematic diagram of the flow direction of the heat exchange fluid in the second magnetic regenerator module of the magnetic refrigerator according to an embodiment of the present invention.

[0037] Figure 2c This is a schematic diagram of the heat exchange fluid flow direction of the heating container in the magnetic refrigeration power measuring device according to an embodiment of the present invention.

[0038] Figures 3a to 3dThe graph shows the changes in cold and hot end temperatures of the magnetic regenerator module over time for the four heating power levels of the heater.

[0039] Figure 3e The graph shows the changes in the cold and hot end temperatures of the magnetic regenerator module over time when the maximum cooling power across the zero temperature span is estimated as the heating power of the heater for verification.

[0040] Figure 4 This is a flowchart of the magnetic refrigeration power testing method according to an embodiment of the present invention.

[0041] The reference numerals in the attached figures are as follows: T1 to T6, first to sixth temperature sensors; H1, first magnetic regenerator module; H2, second magnetic regenerator module; DX1 to DX4, first to fourth one-way valves; RBQ, heating container; 1, heater; C1, first magnetic field system; C2, second magnetic field system. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0043] Figure 1 This is a structural diagram of the magnetic refrigerator and its cooling power testing device according to an embodiment of the present invention. Figure 2a This is a graph showing the change of the magnetic field over time within the magnetic regenerator module of the magnetic refrigerator according to an embodiment of the present invention. Figure 2b This is a schematic diagram of the flow direction of the heat exchange fluid in the second magnetic regenerator module of the magnetic refrigerator according to an embodiment of the present invention. Figure 2c This is a schematic diagram of the heat exchange fluid flow direction of the heating container in the magnetic refrigeration power measuring device according to an embodiment of the present invention. Figures 3a to 3d The graph shows the changes in cold and hot end temperatures of the magnetic regenerator module over time for the four heating power levels of the heater. Figure 3e The graph shows the changes in the cold and hot end temperatures of the magnetic regenerator module over time when the maximum cooling power across the zero temperature span is estimated as the heating power of the heater for verification. Figure 4 This is a flowchart of the magnetic refrigeration power testing method according to an embodiment of the present invention.

[0044] refer to Figure 1 An embodiment of the present invention provides a magnetic refrigeration power testing device, wherein the magnetic refrigeration machine includes a pair of magnetic regenerator modules.

[0045] Specifically, Figure 1 In the embodiment shown, the first magnetic regenerator module H1 and the second magnetic regenerator module H2 each have an active magnetic regenerator (AMR).

[0046] Specifically, the paired magnetic regenerator modules have equal cooling power.

[0047] In other embodiments, a single magnetic regenerator module has multiple active magnetic regenerators connected to each other. For example, a single magnetic regenerator module may include multiple active magnetic regenerators connected in series or multiple active magnetic regenerators connected in parallel.

[0048] The testing apparatus includes the following components:

[0049] The heating container RBQ has a heat exchange fluid inlet and a heat exchange fluid outlet, and a heater 1 for heating the heat exchange fluid flowing through the heating container RBQ;

[0050] The pipeline network is connected to the cold ends of the paired magnetic regenerator modules and the heat exchange fluid inlet and outlet of the heating container RBQ. The pipeline network is equipped with a valve structure to control the flow direction of the heat exchange fluid in the pipeline network to be: from the cold end of any magnetic regenerator module to the heat exchange fluid inlet of the heating container RBQ, and from the heat exchange fluid outlet of the heating container RBQ to the cold end of the other magnetic regenerator module.

[0051] Multiple temperature sensors are used to measure the heat exchange fluid temperature at the hot and cold ends of at least one of the paired magnetic regenerator modules, as well as the heat exchange fluid temperature at the heat exchange fluid inlet and / or outlet of the heating container RBQ.

[0052] Specifically, Figure 1 The arrow above the heating container RBQ indicates the flow direction of the heat exchange fluid inside the heating container RBQ.

[0053] In some embodiments, the heat exchange fluid is water.

[0054] Valve structure (e.g.) Figure 1 The one-way valves (D1 to D4) ensure that the heat exchange fluid flowing through the heating container RBQ always flows in one direction. After one-way flow, the heat exchange fluid in the pipe network travels a greater distance, resulting in more complete heat exchange and a more uniform temperature. This reduces the dead volume in the heat exchange fluid, thereby improving the accuracy of cooling power measurement. In some embodiments, the paired magnetic regenerator modules are a first magnetic regenerator module H1 and a second magnetic regenerator module H2, and the valve structure includes: a first one-way valve DX1, a second one-way valve DX2, a third one-way valve DX3, and a fourth one-way valve DX4.

[0055] The inlet of the first one-way valve DX1 and the outlet of the third one-way valve DX3 are both connected to the cold end of the first magnetic regenerator module H1. The inlet of the second one-way valve DX2 and the outlet of the fourth one-way valve DX4 are both connected to the cold end of the second magnetic regenerator module H2. The outlet of the first one-way valve DX1 and the outlet of the second one-way valve DX2 are both connected to the heat exchange fluid inlet of the heating container RBQ. The inlet of the third one-way valve DX3 and the inlet of the fourth one-way valve DX4 are both connected to the heat exchange fluid outlet of the heating container RBQ.

[0056] The on / off state of a check valve depends on the pressure difference of the fluid at its two ends, without the need for a separate electrical signal to control its on / off state.

[0057] In other embodiments, the check valve may be replaced with an electrically controlled valve.

[0058] refer to Figure 1 The flow direction of the heat exchange fluid in the pipeline network can be as follows: from the cold end of the first magnetic regenerator module H1, through the first one-way valve DX1 to the heat exchange fluid inlet of the heating container RBQ, and then from the heat exchange fluid outlet of the heating container RBQ through the fourth one-way valve DX4 to the second magnetic regenerator module H2. Alternatively, it can be from the cold end of the second magnetic regenerator module H2, through the second one-way valve DX2 to the heat exchange fluid inlet of the heating container RBQ, and then from the heat exchange fluid outlet of the heating container RBQ through the third one-way valve DX3 to the first magnetic regenerator module H1.

[0059] The first magnetic field system C1 provides a periodically varying magnetic field to the first magnetic regenerator module H1. The second magnetic field system C2 provides a periodically varying magnetic field to the second magnetic regenerator module H2.

[0060] In some embodiments, the plurality of temperature sensors include:

[0061] The first temperature sensor T1 is used to measure the temperature of the heat exchange fluid at the hot end of the first magnetic regenerator module H1.

[0062] The second temperature sensor T2 is used to measure the temperature of the heat exchange fluid at the hot end of the second magnetic regenerator module H2.

[0063] The third temperature sensor T3 is used to measure the temperature of the cold end heat exchange fluid of the first magnetic regenerator module H1.

[0064] The fourth temperature sensor T4 is used to measure the temperature of the cold end heat exchange fluid of the second magnetic regenerator module H2.

[0065] The fifth temperature sensor T5 is used to measure the temperature of the heat exchange fluid at the inlet of the heating container RBQ.

[0066] The sixth temperature sensor T6 is used to measure the temperature of the heat exchange fluid at the outlet of the heating container RBQ.

[0067] It should be noted that in some embodiments, the two magnetic regenerator modules are assumed to have identical performance, so temperature sensors only need to be installed at the hot and cold ends of one magnetic regenerator module. In some embodiments, temperature sensors are installed only at the heat exchange fluid inlet or outlet of the heating container RBQ, or only inside the heating container RBQ.

[0068] In some embodiments, the paired magnetic regenerator modules have equal cooling power.

[0069] In some embodiments, the hot-end temperatures of the paired magnetic regenerator modules are set to remain constant and equal.

[0070] refer to Figure 1 and Figures 2a to 2c In the four stages of one cycle of the magnetic refrigerator, the first stage is a transition period where the heat exchange fluid is stationary. In the second stage, when the first magnetic regenerator module H1 is demagnetized, the heat exchange fluid flows out from the cold end of H1, through the first one-way valve DX1, the heating container RBQ (e.g., a thermal compensator), and the fourth one-way valve DX4, and then flows through the magnetized second magnetic regenerator module H2, dissipating heat. In the third stage, the heat exchange fluid remains stationary. In the fourth stage, when the second magnetic regenerator module H2 is demagnetized, the heat exchange fluid flows out from the cold end of H2, sequentially through the second one-way valve DX2, the heating container RBQ, and the third one-way valve DX3, flowing back to the magnetized first magnetic regenerator module H1, dissipating heat, thus completing one cycle.

[0071] Embodiments of the present invention also provide a test method applied to the aforementioned magnetic refrigeration power testing device. (See reference...) Figure 4 The method includes the following steps.

[0072] Step 101: Under the condition that the hot end temperature of the paired magnetic regenerator modules is kept stable and equal, the heating power of the heater 1 is kept at different constant values, and the cold end temperature and hot end temperature of any magnetic regenerator module are measured over time.

[0073] Step 102: When the cold end temperature and hot end temperature of any one of the magnetic regenerator modules tend to be equal as time increases, the corresponding heating power is determined as the maximum cooling power across the zero temperature span.

[0074] For example, if time permits or the range of the maximum cooling power across zero temperature is known, multiple different constant powers can be set for heater 1, with sufficiently small differences between adjacent constant powers. Then, with acceptable accuracy, the heating power of heater 1 under the test condition where the stable value of the cold end temperature of the magnetic regenerator is closest to the stable value of the hot end temperature can be directly determined as the maximum cooling power across zero temperature.

[0075] In some embodiments, the testing method specifically includes:

[0076] Keeping the heating power of heater 1 at different initial constant values, measure the cold end temperature change curve and the hot end temperature change curve of any magnetic regenerator module over time.

[0077] The heating power with the lowest cold-end temperature stability value among the test results where the cold-end temperature stability value is greater than the hot-end temperature stability value is selected as the first heating power, and the heating power with the highest cold-end temperature stability value among the test results where the cold-end temperature stability value is less than the hot-end temperature stability value is selected as the second heating power. The maximum cooling power of the zero-temperature span is determined based on the first heating power, the second heating power, the corresponding cold-end temperature stability values, and the hot-end temperature stability value.

[0078] In some embodiments, determining the maximum cooling power across the zero temperature span based on the first heating power and the second heating power, the corresponding stable cold-end temperature values, and the stable hot-end temperature values ​​includes:

[0079] The predicted value of the maximum cooling power across the zero temperature span is determined by an interpolation method. The cold end stable temperature is set to vary linearly with the heating power between the first heating power and the second heating power. The heating power when the cold end stable temperature is equal to the hot end stable temperature is calculated as the predicted value of the maximum cooling power across the zero temperature span.

[0080] The heating power of the heater 1 is set to the predicted value. When the difference between the stable cold end temperature value and the stable hot end temperature value of any magnetic regenerator module is within the preset error range, the predicted value is used as the measured value of the maximum cooling power at zero temperature span.

[0081] In some embodiments, when the heating power of the heater is set to the predicted value, if the difference between the stable cold-end temperature and the stable hot-end temperature of any one of the magnetic regenerator modules exceeds a preset error range, the stable cold-end temperature corresponding to the first heating power and the second heating power, whichever has the same polarity as the predicted value with respect to the stable hot-end temperature, is replaced with the predicted value. Then, the interpolation method is continued to determine the predicted value of the maximum refrigeration power at zero temperature span. Such cyclic operations are performed until the heating power of the heater 1 is set to the predicted value and the difference between the stable cold-end temperature and the stable hot-end temperature of any one of the magnetic regenerator modules is within the preset error range, at which point the operations stop.

[0082] When there is heat exchange fluid flowing in the regenerator, the heat exchange fluid always flows unidirectionally through the heating container RBQ. The heat exchange fluid undergoes heat exchange within the heating container RBQ. The reciprocatingly flowing heat exchange fluid is unidirectional within the pipeline where the heating container RBQ is located, and there is no dead volume, which is convenient for calculating the refrigeration power of the magnetic refrigeration machine.

[0083] The following is an example for illustration.

[0084] First, keep the hot-end temperatures of the first magnetic regenerator module H1 and the second magnetic regenerator module H2 stable and equal. At this time, the detection results of the first temperature sensor T1 and the second temperature sensor T2 should be constant at the same fixed temperature value.

[0085] Then, respectively test the refrigeration temperature curves of the cold-end temperatures of the first magnetic regenerator module H1 and the second magnetic regenerator module H2 (detected by the third temperature sensor T3 and the fourth temperature sensor T4) over time when the heater 1 is at different powers (such as 0W, x1W, x2W, x3W...). (Note: x1, x2, x3, etc. represent different power values, and x1 < x2 < x3, and W is the power unit watt).

[0086] The greater the heating power, the greater the stable cold-end temperature of the magnetic regenerator module. According to the interpolation method, for example, when the heating power is x2W, the stable cold-end temperature of the magnetic regenerator module is lower than the hot-end temperature, and when the heating power is x3W, the stable cold-end temperature of the magnetic regenerator module is higher than the hot-end temperature. Then it is inferred that the maximum refrigeration power at zero temperature span is between x2W and x3W, and based on the values of the stable cold-end temperature deviating from the hot-end temperature under these two test conditions, a certain refrigeration power is estimated.

[0087] Furthermore, set the heating power of the heater 1 to the estimated power obtained above, and then test the refrigeration temperature curve of the cold-end temperature of the magnetic regenerator module over time to verify whether the estimated value is within the allowable error range.

[0088] If the deviation between the stable cold end temperature and the hot end temperature exceeds the allowable error range, the heating power of heater 1 should be fine-tuned and the verification repeated.

[0089] In a specific test case, the hot-end temperature of the regenerator module remained essentially constant at around 24.3 degrees Celsius. (Reference) Figures 3a to 3d Cooling curves were tested at heating powers of 0W, 10W, 20W, and 30W. It was found that the maximum cooling power across the zero-temperature range should be between 20W and 30W. Based on internal extrapolation, the maximum cooling power across the zero-temperature range was estimated to be 25W. (Finally, refer to...) Figure 3e The heating power of heater 1 is set to 25W, and the stable value of the cold end temperature of the regenerator module is basically equal to that of the hot end temperature.

[0090] Note: Temperature span refers to the temperature difference, specifically the temperature difference between the hot and cold ends of the regenerator in this invention. When the hot end temperature is constant, the cold end temperature gradually decreases as the refrigeration unit operates, forming a temperature curve that gradually decreases over time. After a period of operation, the temperature curve stops decreasing and reaches a stable state, forming a stable temperature difference between the hot and cold ends. This stable temperature difference is largest when no power is applied to the heating container. As the power applied to the heating container increases slightly, this temperature difference gradually decreases. When it decreases to zero temperature difference, it is considered that refrigeration and heating have reached equilibrium, and the applied heating power equals the refrigeration power, i.e., the refrigeration power at zero temperature span.

[0091] The various embodiments in this invention are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0092] The scope of protection of this invention is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its scope and spirit. If these modifications and variations fall within the scope of the claims of this invention and their equivalents, then the intent of this invention also includes these modifications and variations.

Claims

1. A magnetic refrigeration power testing device, characterized in that, The magnetic refrigerator includes paired magnetic regenerator modules, and the testing device includes: A heating container having a heat exchange fluid inlet and a heat exchange fluid outlet, and a heater for heating the heat exchange fluid flowing through the heating container; The pipeline network is connected to the cold ends of the paired magnetic regenerator modules and the heat exchange fluid inlet and outlet of the heating container. The pipeline network is equipped with a valve structure to control the flow direction of the heat exchange fluid in the pipeline network to be: from the cold end of any magnetic regenerator module to the heat exchange fluid inlet of the heating container, and from the heat exchange fluid outlet of the heating container to the cold end of the other magnetic regenerator module. Multiple temperature sensors are used to measure the heat exchange fluid temperature at the hot and cold ends of at least one of the paired magnetic regenerator modules, as well as the heat exchange fluid temperature at the heating container.

2. The apparatus according to claim 1, characterized in that, The paired magnetic regenerator modules are a first magnetic regenerator module and a second magnetic regenerator module, and the valve structure includes: a first check valve, a second check valve, a third check valve and a fourth check valve; The inlet of the first one-way valve and the outlet of the third one-way valve are both connected to the cold end of the first magnetic regenerator module. The inlet of the second one-way valve and the outlet of the fourth one-way valve are both connected to the cold end of the second magnetic regenerator module. The outlets of the first one-way valve and the second one-way valve are both connected to the heat exchange fluid inlet of the heating container. The inlets of the third one-way valve and the fourth one-way valve are both connected to the heat exchange fluid outlet of the heating container.

3. The apparatus according to claim 2, characterized in that, The plurality of temperature sensors include: The first temperature sensor is used to measure the temperature of the heat exchange fluid at the hot end of the first magnetic regenerator module. The second temperature sensor is used to measure the temperature of the heat exchange fluid at the hot end of the second magnetic regenerator module. The third temperature sensor is used to measure the temperature of the cold end heat exchange fluid of the first magnetic regenerator module. The fourth temperature sensor is used to measure the temperature of the cold-end heat exchange fluid of the second magnetic regenerator module. The fifth temperature sensor is used to measure the temperature of the heat exchange fluid at the inlet of the heating container; The sixth temperature sensor is used to measure the temperature of the heat exchange fluid at the outlet of the heating container.

4. The apparatus according to claim 1, characterized in that, The paired magnetic regenerator modules have equal cooling power.

5. The apparatus according to claim 1, characterized in that, The paired magnetic regenerator modules each have one or more active magnetic regenerators that are interconnected.

6. The apparatus according to claim 1, characterized in that, The hot-end temperatures of the paired magnetic regenerator modules are set to remain constant and equal.

7. A test method for the refrigeration power testing device of the magnetic refrigeration mechanism according to any one of claims 1 to 6, characterized in that, include: With the hot end temperatures of the paired magnetic regenerator modules kept stable and equal, the heating power of the heaters was kept at different constant values, and the cold end temperature and hot end temperature of any one magnetic regenerator module were measured over time. When the cold end temperature and hot end temperature of any one of the magnetic regenerator modules tend to be equal as time increases, the corresponding heating power is determined as the maximum cooling power across zero temperature range.

8. The test method according to claim 7, characterized in that, The testing method specifically includes: Keeping the heating power of the heater at different initial constant values, measure the cold end temperature and hot end temperature of any magnetic regenerator module over time. The heating power with the lowest cold-end temperature stability value among the test results where the cold-end temperature stability value is greater than the hot-end temperature stability value is selected as the first heating power, and the heating power with the highest cold-end temperature stability value among the test results where the cold-end temperature stability value is less than the hot-end temperature stability value is selected as the second heating power. The maximum cooling power of the zero-temperature span is determined based on the first heating power, the second heating power, the corresponding cold-end temperature stability values, and the hot-end temperature stability value.

9. The test method according to claim 8, characterized in that, The maximum cooling power across the zero temperature range is determined based on the first heating power, the second heating power, the corresponding stable cold-end temperature values, and the stable hot-end temperature value, including: The predicted value of the maximum cooling power across the zero temperature span is determined by an interpolation method. The cold end stable temperature is set to vary linearly with the heating power between the first heating power and the second heating power. The heating power when the cold end stable temperature is equal to the hot end stable temperature is calculated as the predicted value of the maximum cooling power across the zero temperature span. The heating power of the heater is set to the predicted value. When the difference between the stable cold end temperature value and the stable hot end temperature value of any magnetic regenerator module is within the preset error range, the predicted value is used as the measured value of the maximum cooling power at zero temperature span.

10. The test method according to claim 9, characterized in that, When the heating power of the heater is set to the predicted value, if the difference between the stable cold end temperature value and the stable hot end temperature value of any magnetic regenerator module exceeds a preset error range, the stable cold end temperature value corresponding to the first heating power and the second heating power is replaced with the predicted value, whichever has the same polarity as the predicted value relative to the stable hot end temperature value. The prediction value of the maximum cooling power across the zero temperature span is then determined by the extrapolation method. This process is repeated until the heating power of the heater is set to the predicted value and the difference between the stable cold end temperature value and the stable hot end temperature value of any magnetic regenerator module is within the preset error range.

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