System and method for measuring thermal load of box body of refrigeration device

Abstract

The invention discloses a refrigerating device box thermal load measuring system, which comprises a forward refrigerating system and a thermal parameter measuring system, and is characterized in that the forward refrigerating system is used for providing an actual refrigerating process and thermal load, providing a thermal environment for the thermal parameter measuring system by simulating a refrigerating effect and controlling temperature change, and measuring thermal load of the thermal parameter measuring system; the thermodynamic parameter measuring system is used for monitoring and recording thermodynamic parameters in the refrigeration process so as to evaluate the performance of the forward refrigeration system and calculate the thermal load. According to the measuring system for the thermal load of the refrigerating device box body, through forward heat transfer, the heat transfer load of the refrigerating box body 1 under the actual operation working condition is restored; a steady-state mode and a dynamic mode can be mutually switched, a steady-state thermal load value and a dynamic thermal load curve are measured according to requirements, and measurement of an unsteady-state thermal load can be considered; through the forward measurement method of the thermal load of the refrigerating device box body, the refrigerating temperature of the system is adjustable, and the steady-state and dynamic thermal loads at different refrigerating temperatures can be conveniently measured.

Description

Technical Field

[0001] The invention relates to the technical field of heat load testing of refrigeration devices, and in particular to a system and method for measuring the heat load of a refrigeration device box. Background Art

[0002] The operating energy consumption of refrigeration devices (such as refrigerators and freezers) is mainly affected by the energy efficiency of the refrigeration system and the heat leakage of the refrigeration box. The heat load of the refrigeration box mainly depends on the thermophysical properties of the insulation material and the distribution of the insulation layer. Especially under the demand for personalized design of the spatial structure of refrigeration device products, the thickness distribution of the insulation layer is uneven. The main means to reduce the operating energy consumption of the refrigeration box is to optimize the thickness distribution of the insulation layer, which requires accurate acquisition of the heat load distribution of the existing product refrigeration box, such as door seals, door bodies, side walls, etc.

[0003] In the prior art, the commonly used heat load test method is the reverse heat balance method. The reverse heat balance method is to adjust the heating power through the built-in heat source under the condition that the compressor of the refrigeration device is stopped, so that the temperature inside the box remains higher than a certain value of the external environment. When the temperature difference between the inside and outside of the box remains stable, it is considered to have reached thermal equilibrium. At this time, a heat flux meter can be used to measure the heat flux density of different parts of different refrigeration boxes, and then estimate the heat load. This method is widely used in engineering. The inventor used this method to perform measurements and found that there is a large difference between the measurement conditions of the reverse heat balance method and the actual operating conditions of the box, which makes the measurement of the heat load of the refrigeration device inaccurate. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned background technical problems and to provide a system and method for measuring the heat load of a refrigeration device cabinet.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A system for measuring the heat load of a refrigeration device cabinet, comprising: a forward refrigeration system and a thermal parameter measurement system, wherein the forward refrigeration system is used to provide an actual refrigeration process and heat load, and to provide a thermal environment for the thermal parameter measurement system by simulating refrigeration effects and controlling temperature changes; the forward refrigeration system comprises a refrigeration cabinet, an evaporator is arranged in the refrigeration cabinet, and two branches are arranged at the outlet of the evaporator, and the two branches are a coolant pipeline and a refrigerant pipeline respectively; the coolant pipeline is provided with a first stop valve, a water bath device, a variable frequency circulation pump, and a fourth stop valve in sequence along the flow direction of the coolant, and the refrigerant pipeline is provided with a second stop valve, a heat regenerator, a compressor, a condenser, a capillary tube, and a third stop valve in sequence along the flow direction of the refrigerant, and a condensing fan is arranged on one side of the condenser; the thermal parameter measurement system is used to monitor and record refrigeration Thermodynamic parameters in the process are used to evaluate the performance of the forward refrigeration system and calculate the heat load; the thermal parameter measurement system comprises: a controller, a collector and a workstation arranged outside the refrigeration box, the controller and the collector are connected to the workstation through a signal line; the collector is connected to a heat flux density sheet, a first thermocouple, a second thermocouple, a third thermocouple and a fourth thermocouple arranged inside the refrigeration box, and a fifth thermocouple, a first temperature sensor, a second temperature sensor, a first flow meter, a second flow meter, a third temperature sensor, a first pressure sensor, a fourth temperature sensor and a second pressure sensor located outside the refrigeration box through a signal line; the controller is connected to a temperature-controlled thermocouple, an evaporating fan, a water bath, a variable frequency circulation pump, the condensing fan (13) and the compressor through a signal line.

[0007] As a further solution of the present invention: the temperature T detected by the temperature-controlled thermocouple c As the temperature control point inside the refrigeration box, its coordinates are The first thermocouple, the second thermocouple, the third thermocouple and the fourth thermocouple are arranged crosswise, and the temperatures detected by them are T1, T2, T3 and T4 respectively, and the coordinates are The average temperature of the four points is the characteristic temperature of the air area in the refrigeration box; wherein x0, y0, z0 are the length, width and height of the cavity inside the refrigeration box respectively.

[0008] As a further solution of the present invention, the number n of the heat flux density sheets arranged depends on the thermal resistance distribution of the insulation layers on the six surfaces of the refrigeration box. The six surfaces are divided into n different measurement areas according to the difference in wall thickness δ and thermal conductivity λ of the insulation material. The area of ​​the i-th measurement area is A i , the heat flux density of the i-th measurement area is q i , the heat load of the i-th measurement area is Q i =qi ×A i , the total heat load of the refrigeration box insulation layer is

[0009] A forward measurement method for heat load of a refrigeration device cabinet comprises:

[0010] S1, preset a cooling temperature T s , open the first stop valve and the fourth stop valve, close the second stop valve and the third stop valve, make the forward refrigeration system enter the steady-state refrigeration mode, turn on the evaporation fan, adjust the outlet temperature of the water bath device and the operating frequency of the variable frequency circulation pump, so that the temperature detected by the temperature control sensor is T c Close to the preset cooling temperature T s ;

[0011] S2, T c After stabilization, read the measured values ​​of the first temperature sensor, the second temperature sensor and the first flow meter. The measured values ​​are T medium,in , T medium,out 、M medium , calculate the cooling capacity consumed by the evaporator, that is, the total heat load of the refrigeration box.

[0012] S3, preset a cooling temperature range [T s-low ,T s-up ], open the second stop valve and the third stop valve, close the first stop valve and the fourth stop valve, make the forward refrigeration system enter the dynamic refrigeration mode, adjust the start and stop status of the evaporating fan, condensing fan, and compressor, and make the temperature T detected by the temperature control sensor c In the preset cooling temperature range [T s-low ,T s-up ]Internal fluctuations;

[0013] S4, T c After the temperature remains stable, the measured values ​​of the second flow meter, the third temperature sensor, the first pressure sensor, the fourth temperature sensor, and the second pressure sensor are read. The measured values ​​are M refrigerant,l , T refrigerant,l , P refrigerant,l , T refrigerant,g , P refrigerant,g ;

[0014] S5. According to T refrigerant,l , P refrigerant,l , T refrigerant,g , P refrigerant,g Get the enthalpy value H of liquid refrigerant and gaseous refrigerant in the NIST database refrigerant,l , H refrigerant,g , calculate the cooling capacity consumed by the evaporator, that is, the total heat load of the refrigeration box.

[0015] As a further solution of the present invention: in step S2, the cooling capacity consumed by the evaporator is Q cooling =cM medium (T medium,in -T medium,out ), that is, the total heat load Q of the refrigeration box total =Q cooling ; Wherein, c is the specific heat capacity of the coolant.

[0016] As a further solution of the present invention: in step S5, the cooling capacity consumed by the evaporator is Q cooling =M refrigerant,l (H refrigerant,g -H refrigerant,l ), that is, the total heat load Q of the refrigeration box total =Q cooling .

[0017] As a further solution of the present invention: the door seal and door frame cold bridge heat load Q of the refrigeration box gasket It can be obtained indirectly, that is, Q gasket =Q total -Q insulation .

[0018] Beneficial effects of the present invention:

[0019] (1) In the present invention, the refrigeration device cabinet heat load measurement system restores the heat transfer load of the refrigeration cabinet 1 under actual operating conditions through forward heat transfer.

[0020] (2) In the present invention, the steady-state and dynamic modes can be switched to each other, and the steady-state heat load value and the dynamic heat load curve can be measured according to the needs. Compared with the reverse heat balance method which can only test the heat load under steady-state conditions, the present invention can also take into account the measurement of non-steady-state heat load.

[0021] (3) In the present invention, the forward measurement method of the heat load of the refrigeration device cabinet makes the refrigeration temperature of the system adjustable, which is convenient for measuring the steady-state and dynamic heat loads at different refrigeration temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] Figure 1 It is a structural schematic diagram of a system for measuring heat load of a refrigeration device box according to the present invention;

[0024] Figure 2 It is a flow chart of a method for measuring a heat load of a refrigeration device cabinet of the present invention;

[0025] Figure 3 It is a temperature cloud diagram of heat transfer of the door seal of the refrigeration box under the actual working conditions of the present invention;

[0026] Figure 4 It is a temperature cloud diagram of heat transfer of the door seal of a refrigeration box under the reverse heat balance method working condition in the prior art of the present invention;

[0027] Figure 5 This is a schematic diagram of the thermal resistance distribution of the 133L refrigerator door of the present invention;

[0028] Figure 6 Schematic diagram of thermal resistance distribution of the rear wall of a 133L refrigerator of the present invention;

[0029] Figure 7 Schematic diagram of thermal resistance distribution of the left wall of a 133L refrigerator of the present invention;

[0030] Figure 8 Schematic diagram of thermal resistance distribution of the right wall of a 133L refrigerator of the present invention;

[0031] Fig. 9 Schematic diagram of thermal resistance distribution of the top wall of a 133L refrigerator of the present invention;

[0032] Fig.10 It is a schematic diagram of the thermal resistance distribution of the bottom wall of a 133L refrigerator of the present invention.

[0033] In the figure:

[0034] 1. Refrigeration box; 2. Evaporator; 3. Evaporating fan; 4. First stop valve; 5. Second stop valve; 6. Water bath device; 7. Frequency conversion circulation pump; 8. Third stop valve; 9. Fourth stop valve; 10. Capillary; 11. Regenerator; 12. Condenser; 13. Condensing fan; 14. Compressor; 15. Controller; 16. Collector; 17. Workstation; 18. Heat flux density sheet; 19. Temperature control sensor; 20. First thermocouple; 21. Second thermocouple; 22. Third thermocouple; 23. Fourth thermocouple; 24. Fifth thermocouple; 25. First temperature sensor; 26. Second temperature sensor; 27. First flowmeter; 28. Second flowmeter; 29. ​​Third temperature sensor; 30. First pressure sensor; 31. Fourth temperature sensor; 32. Second pressure sensor. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1As shown, the present invention is a measurement system for the heat load of a refrigeration device cabinet, including: a forward refrigeration system and a thermal parameter measurement system. The forward refrigeration system is used to provide an actual refrigeration process and heat load, and provides a thermal environment for the thermal parameter measurement system by simulating refrigeration effects and controlling temperature changes.

[0037] Specifically, the forward refrigeration system includes a refrigeration box 1, an evaporator 2 is arranged at the back plate position in the refrigeration box 1, and an evaporation fan 3 is arranged on the top of the evaporator 2. Two branches are arranged at the outlet of the evaporator 2, and the two branches are a coolant pipeline and a refrigerant pipeline respectively.

[0038] Furthermore, the refrigerant pipeline is provided with a first stop valve 4, a water bath device 6, a variable frequency circulation pump 7, and a fourth stop valve 9 in sequence along the flow direction of the refrigerant. The refrigerant pipeline is provided with a second stop valve 5, a regenerator 11, a compressor 14, a condenser 12, a capillary tube 10, and a third stop valve 8 in sequence along the flow direction of the refrigerant, and a condensing fan 13 is provided on one side of the condenser 12. One end of the refrigerant pipeline is connected to the outlet of the evaporator 2, and the other end is connected to the inlet of the evaporator 2. Correspondingly, one end of the refrigerant pipeline is connected to the outlet of the evaporator 2, and the other end is also connected to the inlet of the evaporator 2.

[0039] See also Figure 1 As shown, the thermal parameter measurement system is used to monitor and record the thermodynamic parameters in the refrigeration process to evaluate the performance of the forward refrigeration system and calculate the heat load.

[0040] Specifically, the thermal parameter measurement system includes: a controller 15, a collector 16 and a workstation 17 arranged outside the refrigeration box 1, and the controller 15 and the collector 16 are connected to the workstation 17 through a signal line.

[0041] Furthermore, the collector 16 is connected to the heat flux density sheet 18, the first thermocouple 20, the second thermocouple 21, the third thermocouple 22 and the fourth thermocouple 23 arranged inside the refrigeration box 1, and the fifth thermocouple 24, the first temperature sensor 25, the second temperature sensor 26, the first flowmeter 27, the second flowmeter 28, the third temperature sensor 29, the first pressure sensor 30, the fourth temperature sensor 31 and the second pressure sensor 32 located outside the refrigeration box 1 through a signal line. Among them, the fifth thermocouple 24 is an environmental thermocouple for detecting the external ambient temperature. The first temperature sensor 25, the second temperature sensor 26 and the first flowmeter 27 are all arranged on the coolant pipeline, the first temperature sensor 25 is used to monitor the coolant temperature at the inlet of the water bath device 6, the second temperature sensor 26 is used to monitor the coolant temperature at the outlet of the water bath device 6, and the first flowmeter 27 is used to monitor the real-time flow of the coolant. The second flow meter 28, the third temperature sensor 29, the first pressure sensor 30, the fourth temperature sensor 31 and the second pressure sensor 32 are all arranged on the refrigerant pipeline. The second flow meter 28 is used to monitor the flow rate of liquid refrigerant, the third temperature sensor 29 is used to monitor the temperature of liquid refrigerant, the first pressure sensor 30 is used to monitor the pressure of liquid refrigerant in the refrigerant pipeline, the fourth temperature sensor 31 is used to monitor the temperature of gaseous refrigerant, and the second pressure sensor 32 is used to monitor the pressure of gaseous refrigerant in the refrigerant pipeline.

[0042] Furthermore, the controller 15 is connected to the temperature control thermocouple 19, the evaporation fan 3, the water bath device 6, the variable frequency circulation pump 7, the condensation fan 13 and the compressor 14 through signal lines. The temperature control thermocouple 19 is arranged inside the refrigeration box 1.

[0043] Specifically, the temperature T detected by the temperature control thermocouple 19 c As the temperature control point inside the refrigeration box 1, its coordinates are The first thermocouple 20, the second thermocouple 21, the third thermocouple 22, and the fourth thermocouple 23 are arranged crosswise, and the temperatures detected by them are T1, T2, T3, and T4 respectively. The coordinates of the first thermocouple 20, the second thermocouple 21, the third thermocouple 22, and the fourth thermocouple 23 are respectively The average temperature of the four points is the characteristic temperature of the air area in the refrigeration box 1. Wherein, x0, y0, z0 are the length, width and height of the cavity inside the refrigeration box 1 respectively.

[0044] Moreover, the number n of heat flux density sheets 18 depends on the thermal resistance distribution of the insulation layers on the six surfaces of the refrigeration box 1. The six surfaces are divided into n different measurement areas according to the difference in wall thickness δ and thermal conductivity λ of the insulation material. The area of ​​the i-th measurement area is A. i, the heat flux density of the i-th measurement area is q i , the heat load of the i-th measurement area is Q i =q i ×A i , the total heat load of the insulation layer of the refrigeration box 1 is

[0045] See also Figure 3-Figure 4 As shown, the heat load test method commonly used in the prior art is the reverse heat balance method, which is widely used in engineering. The inventor uses the reverse heat balance method for measurement, but the inventor finds that there is a large difference between the measurement conditions of the reverse heat balance method and the actual operating conditions of the box, as follows:

[0046] In actual operating conditions, the anti-condensation pipe at the door frame of the cabinet is in a heated state. Under the reverse heat balance method, the refrigeration device is powered off, the compressor is not turned on, the anti-condensation pipe fails to heat up, and the local heat transfer state of the cabinet is changed.

[0047] Moreover, the fan inside the refrigeration unit is in intermittent operation and is located on the side of the evaporator. Under the reverse heat balance method, the original fan does not run and the external fan cannot be placed on the side of the evaporator, causing the flow field inside the refrigeration box to be different from the flow field under actual operation, thereby changing the heat transfer state inside the box.

[0048] Under the reverse heat balance method, the internal temperature is higher than the external temperature due to the built-in heat source, and the direction of heat transfer is from the inside of the refrigeration box to the external environment, which is inconsistent with the actual operating conditions of the refrigeration device products. In actual operation, the external temperature is higher than the internal temperature, and the direction of heat transfer is from the external environment to the inside of the refrigeration box. Due to the irregular insulation structure of the refrigeration box (such as door shelves, door seals, drawer ribs, etc.), when the heat flow is transferred inward and outward, although the temperature difference is the same, the heat load is different.

[0049] The purpose of the reverse heat balance method is to maintain a thermal equilibrium state, and it can only test the heat load under steady-state conditions. However, in the actual operation of the refrigeration device, the start and stop states of the compressor are controlled by temperature, and the refrigeration box is always in a non-steady-state condition with periodic temperature rise and drop. The non-steady-state heat load is required for measurement, and the reverse heat balance method cannot take into account the non-steady-state heat load.

[0050] In addition, according to the public paper "Research Progress on Key Technologies for Improving the Performance of Flexible Contact Sealing Mechanisms in Refrigeration Devices", under actual refrigeration conditions and reverse thermal equilibrium, the heat load of the door seal was 2.47W / m and 3.23W / m respectively, with a deviation of more than 30%, further confirming that the accuracy of heat load measurement by the reverse thermal balance method is not high.

[0051] See also Figure 2As shown, in another embodiment, a forward measurement method of a heat load of a refrigeration device cabinet includes:

[0052] S1, preset a cooling temperature T s , open the first stop valve 4 and the fourth stop valve 9, close the second stop valve 5 and the third stop valve 8, so that the forward refrigeration system enters the steady-state refrigeration mode, turn on the evaporation fan 3, adjust the outlet temperature of the water bath device 6 and the operating frequency of the variable frequency circulation pump 7, so that the temperature T detected by the temperature control sensor 19 c Close to the preset cooling temperature T s .

[0053] S2, T c After the temperature remains stable, the measured values ​​of the first temperature sensor 25, the second temperature sensor 26 and the first flow meter 27 are read. The measured values ​​are T medium,in , T medium,out 、M medium , calculate the cooling capacity consumed by the evaporator 2, that is, the total heat load of the refrigeration box 1. At this time, the total heat load of the refrigeration box 1 is a steady-state heat load.

[0054] The cooling capacity consumed by evaporator 2 is Q cooling =cM medium (T medium,in -T medium,out ), that is, the total heat load Q of the refrigeration box 1 total =Q cooling . Where c is the specific heat capacity of the coolant.

[0055] S3, preset a cooling temperature range [T s-low ,T s-up ], open the second stop valve 5 and the third stop valve 8, close the first stop valve 4 and the fourth stop valve 9, so that the forward refrigeration system enters the dynamic refrigeration mode, adjust the start and stop states of the evaporating fan 3, the condensing fan 13, and the compressor 14, and make the temperature T detected by the temperature control sensor 19 c In the preset cooling temperature range [T s-low ,T s-up ]Internal fluctuations.

[0056] S4, T c After the temperature remains stable, the measured values ​​of the second flow meter 28, the third temperature sensor 29, the first pressure sensor 30, the fourth temperature sensor 31, and the second pressure sensor 32 are read. The measured values ​​are M refrigerant,l , T refrigerant,l , P refrigerant,l , T refrigerant,g , P refrigerant,g .

[0057] S5. According to T refrigerant,l , Prefrigerant,l , T refrigerant,g , P refrigerant,g Get the enthalpy value H of liquid refrigerant and gaseous refrigerant in the NIST database refrigerant,l , H refrigerant,g , calculate the cooling capacity consumed by the evaporator 2, that is, the total heat load of the refrigeration box 1. At this time, the total heat load of the refrigeration box 1 is a dynamic heat load.

[0058] The cooling capacity consumed by evaporator 2 is Q cooling =M refrigerant,l (H refrigerant,g -H refrigerant,l ), that is, the total heat load Q of the refrigeration box 1 total =Q cooling .

[0059] It is understandable that the door seal and door frame cold bridge heat load Q of the refrigeration box 1 gasket It can be obtained indirectly, that is, Q gasket =Q total -Q insulation .

[0060] In the present application, the measurement system of the heat load of the refrigeration cabinet restores the heat transfer load of the actual operating condition of the refrigeration cabinet 1 through forward heat transfer, and can switch between steady-state and dynamic modes to measure the steady-state heat load value and dynamic heat load curve according to demand. Compared with the reverse heat balance method, which can only test the heat load under steady-state conditions, the present invention can take into account the measurement of non-steady-state heat load.

[0061] By using the forward measurement method of the heat load of the refrigeration device box, the refrigeration temperature of the system can be adjusted, which is convenient for measuring the steady-state and dynamic heat loads at different refrigeration temperatures.

[0062] The following are experiments and experimental data using the system and method for measuring the heat load of the refrigeration device box in the present invention:

[0063] See also Figure 5-Figure 10 As shown, for a 133L single-door refrigerator, the ambient temperature is set to 25°C and the temperature inside the refrigerator is set to -18°C. According to the thermal resistance distribution, the wall surface of the 133L single-door refrigeration box is divided into 48 measurement areas.

[0064] See also Figure 1 As shown, the first stop valve 4 and the fourth stop valve 9 are opened, the second stop valve 5 and the third stop valve 8 are closed, the forward refrigeration system enters the steady-state refrigeration mode, the evaporation fan 3 is turned on, the outlet temperature of the water bath device 6 and the operating frequency of the variable frequency circulation pump 7 are adjusted, and the temperature detected by the temperature control sensor 19 is close to the preset refrigeration temperature, that is, -18°C. At this time, the heat flux density and heat load of each part of the refrigerator are measured using the heat flux density sheet 18, and the specific data are shown in the following table:

[0065] Table 1 Heat loads of different parts of the refrigerator under positive steady-state equilibrium conditions

[0066]

[0067]

[0068] From Table 1, we know that the heat load of the refrigerator wall is 14.311W, and the cooling capacity measured by the flow rate of the refrigerant and the temperature difference before and after the evaporator is 16.512W. It can be seen that the heat load of the door seal is 2.201W, and the heat load accounts for 13.3%.

[0069] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. A system for measuring heat load of a refrigeration device cabinet, characterized in that: include: A forward refrigeration system and a thermal parameter measurement system, wherein the forward refrigeration system is used to provide an actual refrigeration process and heat load, and to provide a thermal environment for the thermal parameter measurement system by simulating refrigeration effects and controlling temperature changes; The forward refrigeration system comprises a refrigeration box (1), an evaporator (2) is arranged in the refrigeration box (1), and two branches are arranged at the outlet of the evaporator (2), the two branches are respectively a coolant pipeline and a refrigerant pipeline; The refrigerant pipeline is provided with a first stop valve (4), a water bath device (6), a variable frequency circulation pump (7), and a fourth stop valve (9) in sequence along the flow direction of the refrigerant; the refrigerant pipeline is provided with a second stop valve (5), a heat regenerator (11), a compressor (14), a condenser (12), a capillary tube (10), and a third stop valve (8) in sequence along the flow direction of the refrigerant; and a condensing fan (13) is provided on one side of the condenser (12); The thermal parameter measurement system is used to monitor and record the thermodynamic parameters during the refrigeration process, so as to evaluate the performance of the forward refrigeration system and calculate the heat load; The thermal parameter measurement system comprises: a controller (15), a collector (16) and a workstation (17) arranged outside the refrigeration box (1), wherein the controller (15) and the collector (16) are connected to the workstation (17) via a signal line; The collector (16) is connected to a heat flux sheet (18), a first thermocouple (20), a second thermocouple (21), a third thermocouple (22) and a fourth thermocouple (23) arranged inside the refrigeration box (1), and a fifth thermocouple (24), a first temperature sensor (25), a second temperature sensor (26), a first flow meter (27), a second flow meter (28), a third temperature sensor (29), a first pressure sensor (30), a fourth temperature sensor (31) and a second pressure sensor (32) located outside the refrigeration box (1) via a signal line; The controller (15) is connected to a temperature-controlled thermocouple (19), an evaporating fan (3), a water bath device (6), a variable-frequency circulation pump (7), the condensing fan (13) and the compressor (14) via a signal line.

2. A refrigeration device cabinet heat load measurement system according to claim 1, characterized in that: The temperature T detected by the temperature-controlled thermocouple (19) c As the temperature control point inside the refrigeration box (1), its coordinates are The first thermocouple (20), the second thermocouple (21), the third thermocouple (22), and the fourth thermocouple (23) are arranged crosswise, and the temperatures detected by them are T1, T2, T3, and T4, respectively, and the coordinates are The average temperature of the four points is the characteristic temperature of the air area in the refrigeration box (1); Among them, x0, y0, z0 are respectively the length, width and height of the internal cavity of the refrigeration box (1).

3. A refrigeration device box heat load measurement system according to claim 1, characterized in that: The number n of heat flux density sheets (18) arranged depends on the thermal resistance distribution of the insulation layers on the six surfaces of the refrigeration box (1). The six surfaces are divided into n different measurement areas according to the difference in wall thickness δ and thermal conductivity λ of the insulation material. The area of ​​the i-th measurement area is A i , the heat flux density of the i-th measurement area is q i , the heat load of the i-th measurement area is Q i =q i ×A i The total heat load of the insulation layer of the refrigeration box (1) is 4. A method for using the refrigeration device cabinet heat load measurement system according to any one of claims 1 to 3, characterized in that: include: S1. Preset a cooling temperature T s , open the first stop valve (4) and the fourth stop valve (9), close the second stop valve (5) and the third stop valve (8), so that the forward refrigeration system enters the steady-state refrigeration mode, turn on the evaporation fan (3), adjust the outlet temperature of the water bath device (6) and the operating frequency of the variable frequency circulation pump (7), so that the temperature T detected by the temperature control sensor (19) is c Close to the preset cooling temperature T s ; S2, T c After the temperature remains stable, the measured values ​​of the first temperature sensor (25), the second temperature sensor (26) and the first flow meter (27) are read. The measured values ​​are T medium,in 、T medium,out 、M medium , calculate the cooling capacity consumed by the evaporator (2), that is, the total heat load of the refrigeration box (1). S3, preset a cooling temperature range [T s-low ,T s-up ], open the second stop valve (5) and the third stop valve (8), close the first stop valve (4) and the fourth stop valve (9), so that the forward refrigeration system enters the dynamic refrigeration mode, adjusts the start and stop states of the evaporating fan (3), the condensing fan (13), and the compressor (14), and makes the temperature T detected by the temperature control sensor (19) c In the preset cooling temperature range [T s-low ,T s-up ]Internal fluctuations; S4, T c After the temperature remains stable, the measured values ​​of the second flow meter (28), the third temperature sensor (29), the first pressure sensor (30), the fourth temperature sensor (31), and the second pressure sensor (32) are read. The measured values ​​are M refrigerant,l , T refrigerant,l , P refrigerant,l , T refrigerant,g , P refrigerant,g ; S5. According to T refrigerant,l , P refrigerant,l 、T refrigerant,g , P refrigerant,g Get the enthalpy value H of liquid refrigerant and gaseous refrigerant in the NIST database refrigerant,l , H refrigerant,g , calculate the cooling capacity consumed by the evaporator (2), that is, the total heat load of the refrigeration box (1).

5. The method according to claim 4, characterized in that: In step S2, the cooling capacity consumed by the evaporator (2) is Q cooling =cM medium (T medium,in -T medium,out ), i.e. the total heat load Q of the refrigeration box (1) total =Q cooling ; Where c is the specific heat capacity of the coolant.

6. The method according to claim 4, characterized in that: In step S5, the cooling capacity consumed by the evaporator (2) is Q cooling =M refrigerant,l (H refrigerant,g -H refrigerant,l ), i.e. the total heat load Q of the refrigeration box (1) total =Q cooling .

7. The method according to claim 4, characterized in that: The door seal and door frame cold bridge heat load Q of the refrigeration box (1) gasket It can be obtained indirectly, that is, Q gasket =Q total -Q insulation .

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