Defrosting system and method for environmental test box

Abstract

The invention discloses an environmental test chamber defrosting system and method, and relates to the technical field of detection equipment. The defrosting system for the environmental test box comprises a compressor, a condenser, at least two evaporators, a plurality of first loops and a plurality of second loops, the condenser is connected with an exhaust outlet of the compressor, and each evaporator has a refrigeration mode and a defrosting mode; the multiple first loops correspond to the evaporators respectively, and any first loop is connected with the compressor, the condenser and the corresponding evaporator and is configured as a refrigerating loop of the corresponding evaporator; the multiple second loops correspond to the evaporators respectively, and any second loop is connected with the compressor and the corresponding evaporator and is configured as a defrosting loop of the corresponding evaporator; and when one evaporator is in the defrosting mode, at least one evaporator is in the refrigeration mode. Based on the technical scheme disclosed by the invention, the defrosting energy consumption can be reduced, the defrosting efficiency can be ensured, the temperature fluctuation in the box can be reduced, and the accuracy of a test result can be improved.

Description

Technical Field

[0001] This invention relates to the field of testing equipment technology, specifically to a defrosting system and method for an environmental test chamber. Background Technology

[0002] When environmental test chambers operate at low temperatures, frost easily forms on the evaporator surface, affecting the equipment's cooling efficiency and operational stability. In related technologies, defrosting is typically achieved using heating wires or hot gas.

[0003] However, electric defrosting consumes a lot of energy and takes a long time. Hot gas defrosting, on the other hand, usually involves intermittently controlling the environmental test chamber to enter defrosting mode, which can easily cause temperature fluctuations inside the chamber and affect the accuracy of the test results. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical defrosting defrosting system and method for environmental test chambers, and to solve the technical problems of high energy consumption, low defrosting efficiency, and easy temperature fluctuation inside the chamber that affect the accuracy of test results in the prior art.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a defrosting system for an environmental test chamber, comprising: A compressor is used to compress refrigerant and drive its flow. A condenser, connected to the exhaust outlet of the compressor, is used to condense the refrigerant; At least two evaporators, each with a cooling mode and a defrosting mode; Multiple first loops, each corresponding to a specific evaporator, are provided. Each first loop is connected to the compressor, the condenser, and the corresponding evaporator, and is configured as the refrigeration loop for that evaporator. Multiple second loops, each corresponding to a different evaporator, are provided. Each second loop is connected to the compressor and the corresponding evaporator and is configured as the defrosting loop for the corresponding evaporator. The refrigerant output from the compressor flows along any first loop, passes through the condenser into the corresponding evaporator, and returns to the compressor, thus realizing the refrigeration cycle of the corresponding evaporator; the refrigerant output from the compressor circulates between the compressor and the corresponding evaporator along any second loop, thus realizing the defrosting cycle of the corresponding evaporator; when an evaporator is in defrosting mode, at least one evaporator is in refrigeration mode.

[0006] In some embodiments, the defrost outlet of any of the evaporators is connected to the refrigeration inlet of other evaporators via a pipeline, so that the refrigerant discharged when any of the evaporators defrosts can enter other evaporators in refrigeration mode and participate in the refrigeration cycle of the evaporators in refrigeration mode.

[0007] In some embodiments, the refrigerant flow direction of any of the evaporators is opposite in cooling mode and defrost mode; the cooling inlet of any of the evaporators is connected to a main pipeline, which connects to the cooling inlets of other evaporators when the corresponding evaporator is defrosting, and forms a refrigerant discharge pipeline when the corresponding evaporator is defrosting; a throttling valve is provided on the main pipeline, and a bypass pipeline is also connected between the inlet and outlet of the throttling valve, and a solenoid valve is provided on the bypass pipeline.

[0008] In some embodiments, the environmental test chamber defrosting system includes: Multiple first solenoid valves are respectively disposed on the multiple first circuits, and are used to control the opening or closing of the corresponding first circuit; Multiple second solenoid valves are respectively disposed on the multiple second circuits, and are used to control the opening or closing of the corresponding second circuit; and The control module is electrically connected to the plurality of first solenoid valves and the plurality of second solenoid valves respectively, and is used to realize automatic control.

[0009] In some embodiments, the environmental test chamber defrosting system further includes multiple regulating valves, which are respectively disposed on the multiple second circuits and located between the exhaust outlet of the compressor and the defrosting inlet of the corresponding evaporator. The multiple regulating valves are electrically connected to the control module and are used to adjust the defrosting flow rate of the corresponding evaporator.

[0010] In some embodiments, the environmental test chamber defrosting system further includes: Multiple first temperature sensors are respectively installed on each evaporator and electrically connected to the control module, respectively used to monitor the surface temperature of the corresponding evaporator; and The second temperature sensor is installed inside the environmental test chamber and electrically connected to the control module to monitor the temperature inside the environmental test chamber.

[0011] In some embodiments, the environmental test chamber defrosting system further includes: Multiple third temperature sensors are respectively installed at the defrost outlet of each evaporator and electrically connected to the control module, respectively used to monitor the temperature at the defrost outlet of each evaporator; and A pressure sensor is installed at the refrigerant outlet of the condenser and electrically connected to the control module to monitor the pressure at the refrigerant outlet of the condenser.

[0012] Secondly, the present invention also provides a defrosting method for an environmental test chamber, applied to the aforementioned defrosting system for an environmental test chamber, comprising the following steps: Determine the frosting condition of each evaporator; Based on the frosting condition of each evaporator, determine whether each evaporator has met the preset defrosting conditions; Based on the determined results, adjust the operating mode of each evaporator in the system accordingly; Specifically, for evaporators whose frosting conditions meet the preset conditions, their operating mode is adjusted to defrost mode; for evaporators whose frosting conditions do not meet the preset conditions, at least one of the evaporators is set to cooling mode.

[0013] In some embodiments, when determining the frosting condition of the evaporator and defrosting one of the evaporators, the environmental test chamber defrosting method further includes: Obtain the pressure value at the condenser outlet; Real-time monitoring of the temperature at the defrost outlet of the evaporator; Adjust the refrigerant flow rate during evaporator defrosting until the temperature reaches the saturation temperature corresponding to the pressure value, or is lower than the saturation temperature and the temperature difference reaches the specified temperature difference.

[0014] In some embodiments, when the frosting conditions of multiple evaporators simultaneously meet the preset defrosting conditions, the environmental test chamber defrosting method further includes: Obtain the surface temperature of each evaporator; Based on the surface temperature of each evaporator, the evaporators are ordered for defrosting. According to the defrosting sequence, each evaporator is controlled to perform alternating defrosting until each evaporator no longer meets the preset defrosting conditions.

[0015] Compared with existing technologies, the present invention provides a defrosting system and method for an environmental test chamber. By setting up a compressor, a condenser, and multiple evaporators, each evaporator is connected to the compressor and condenser via a first loop and directly connected to the compressor via a second loop. This allows the refrigerant discharged from the compressor to enter the evaporator via the condenser to achieve a refrigeration cycle, or to achieve a defrosting cycle between the compressor and the evaporator via the second loop. This approach avoids introducing additional energy consumption, reduces defrosting energy consumption, ensures defrosting efficiency, and ensures that at least one evaporator is in cooling mode during defrosting to maintain the stability of the chamber temperature, thereby reducing temperature fluctuations and ensuring the accuracy of test results. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the overall structure of the defrosting system of the environmental test chamber in one embodiment of the present invention; Figure 2 This is a schematic diagram of the defrosting system of the environmental test chamber during defrosting of the first evaporator in one embodiment of the present invention; Figure 3 This is a schematic diagram of the defrosting system of the environmental test chamber during defrosting of the second evaporator in one embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the control module and its supporting components in one embodiment of the present invention; Figure 5 This is a schematic flowchart of an environmental test chamber defrosting method in one embodiment of the present invention; Figure 6 This is a schematic diagram of the control logic of the defrosting method for an environmental test chamber in one embodiment of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1. Compressor; 2. Condenser; 3. Evaporator; 31. First Evaporator; 32. Second Evaporator; 4. First Pipeline; 5. Second Pipeline; 6. Solenoid Valve; 61. Solenoid Valve a; 62. Solenoid Valve b; 63. Solenoid Valve c; 64. Solenoid Valve d; 65. Solenoid Valve e; 66. Solenoid Valve f; 67. Solenoid Valve g; 7. Throttling Valve; 71. Throttling Valve a; 72. Throttling Valve b; 8. Regulating Valve; 81. Regulating Valve a; 82. Regulating Valve b; 9. First Temperature Sensor; 10. Second Temperature Sensor; 11. Control Module; 12. Third Temperature Sensor; 13. Pressure Sensor; 14. Third Pipeline; 15. Fourth Pipeline; 16. Main Pipeline; 17. Bypass Pipeline. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] To address the aforementioned technical problems, this invention provides an environmental test chamber defrosting system and method, which not only avoids introducing additional energy consumption and reduces defrosting energy consumption, ensuring defrosting efficiency, but also maintains the stability of the chamber temperature, reduces temperature fluctuations, and ensures the accuracy of test results.

[0020] Please see Figure 1 , Figure 1This is a schematic diagram of the overall structure of a defrosting system for an environmental test chamber according to an embodiment of the present invention. This defrosting system can be applied to environmental test chambers, as well as other similar refrigeration equipment with defrosting requirements (such as refrigerators, freezers, etc.). For ease of understanding, the specific structure and principle of the defrosting system will be described below using an environmental test chamber as an example, but this does not mean that it is only applicable to this application scenario.

[0021] In this embodiment, the defrosting system is set up inside an environmental test chamber. It includes a compressor 1, a condenser 2, and an evaporator 3. The condenser 2 is connected to the exhaust outlet of the compressor 1, and the evaporator 3 is connected to the compressor 1 through a system loop consisting of pipes.

[0022] In practical applications, compressor 1 can compress the refrigerant and drive the refrigerant to flow in the system loop, so that the refrigerant can circulate between compressor 1 and evaporator 3.

[0023] The evaporator 3 has a cooling mode and a defrost mode. In the cooling mode, the refrigerant enters the evaporator 3 through the condenser via the system loop and can absorb heat to achieve cooling. In the defrost mode, the refrigerant can directly enter the evaporator 3 and release heat to achieve defrost.

[0024] In this embodiment, to facilitate the cooling and defrosting of the evaporator 3, the above-mentioned system circuit includes a first circuit and a second circuit.

[0025] The first circuit connects compressor 1, condenser 2, and evaporator 3, forming the refrigeration circuit for evaporator 3; while the second circuit connects compressor 1 and evaporator 3, forming the defrosting circuit for evaporator 3. The first and second circuits can be used to realize the refrigeration cycle and defrosting cycle of the refrigerant, respectively.

[0026] In one embodiment, please refer to Figure 1 To avoid fluctuations in the internal temperature of the environmental test chamber caused by the switching of the working mode of the evaporator 3, the evaporator 3 can be set to two, which can be referred to as the first evaporator 31 and the second evaporator 32 respectively.

[0027] Based on this, the first evaporator 31 and the second evaporator 32 can be connected in parallel in the system loop. In this case, the two loops corresponding to the first evaporator 31 can be denoted as first loop a and second loop a, respectively. The first evaporator 31 can achieve both cooling and defrosting modes through first loop a and second loop a, respectively. Similarly, the two loops corresponding to the second evaporator 32 can be denoted as first loop b and second loop b, respectively. The second evaporator 32 can achieve both cooling and defrosting modes through first loop b and second loop b, respectively.

[0028] Specifically, the system loop includes a first pipe 4 and a second pipe 5. The first pipe 4 and the second pipe 5 are respectively connected to the exhaust port and suction port of the compressor 1 (i.e., the refrigerant inlet on the compressor 1). The condenser 2 can be installed on the first pipe 4, while the first evaporator 31 and the second evaporator 32 can be installed in parallel between the first pipe 4 and the second pipe 5 through pipes.

[0029] For the first evaporator 31, the exhaust outlet of the compressor 1 is connected to the condenser 2 through the first pipe 4. The refrigerant outlet of the condenser 2 is connected to one of the connection ports on the first evaporator 31 (i.e., the refrigerant inlet in the cooling mode, which can be referred to as the cooling inlet) through a pipe. The other connection port of the first evaporator 31 (i.e., the refrigerant outlet in the cooling mode, which can be referred to as the cooling outlet) can be connected to the second pipe 5 through a pipe. The end of the second pipe 5 away from the first evaporator 31 can be connected to the suction port of the compressor 1.

[0030] For the second evaporator 32, the refrigerant outlet of the condenser 2 can also be connected to one of the connection ports on the second evaporator 32 (i.e., the refrigerant inlet in the cooling mode, which can be referred to as the cooling inlet) through a pipeline, and the other connection port of the second evaporator 32 (i.e., the refrigerant outlet in the cooling mode, which can be referred to as the cooling outlet) can be connected to the second pipeline 5 through a pipeline.

[0031] Taking the first evaporator 31 as an example, the compressor 1 can compress the refrigerant to form a high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant flows along the first pipe 4 to the condenser 2, where it condenses and forms a high-pressure liquid refrigerant. The high-pressure liquid refrigerant can then enter the first evaporator 31, where it absorbs heat and evaporates to form a low-temperature, low-pressure gaseous refrigerant. This low-temperature, low-pressure gaseous refrigerant can return to the compressor 1's suction port along the second pipe 5, thus realizing the refrigeration cycle of the first evaporator 31. In this way, the system loop corresponding to this refrigeration cycle constitutes the aforementioned first loop a.

[0032] Similarly, after the refrigerant is condensed into a low-temperature liquid refrigerant in the condenser 2, this low-temperature liquid refrigerant can also enter the second evaporator 32 through the pipeline. Finally, the refrigerant can also return to the suction port of the compressor 1 along the second pipeline 5, thereby realizing the refrigeration cycle of the second evaporator 32. In this way, the system loop corresponding to this refrigeration cycle can constitute the first loop b mentioned above.

[0033] Based on this, the system circuit is also equipped with solenoid valve A61, throttle valve A71, and throttle valve B72. Solenoid valve A61 can be installed on the first pipe 4, and throttle valves A71 and B72 can be installed on the pipes on the side where the refrigerant inlet of the first evaporator 31 and the second evaporator 32 are located, respectively. Simultaneously, solenoid valves B62 and C63 can also be installed on the system circuit, and they can be installed on the pipes on the side where the refrigerant outlet of the first evaporator 31 and the second evaporator 32 are located, respectively.

[0034] Among them, the solenoid valve a61 can be installed on the pipeline of the condenser 2 away from the exhaust outlet of the compressor 1, and it can control the opening or closing of the first pipeline 4.

[0035] Throttling valve a71 and throttling valve b72 can be installed on the parallel pipeline between the first pipeline 4 and the second pipeline 5, which can respectively throttle and reduce the pressure of the refrigerant entering the first evaporator 31 and the second evaporator 32.

[0036] Solenoid valves b62 and c63 can be installed on the parallel pipeline between the first pipeline 4 and the second pipeline 5, and can be located on the pipelines on the side where the refrigeration outlets of the first evaporator 31 and the second evaporator 32 are located, respectively. They can control the opening or closing of the pipelines on the side where the refrigeration outlets of the two evaporators 3 are located.

[0037] In one embodiment, please refer to Figure 1 To simplify the system loop and improve the defrosting effect, when defrosting the evaporator 3 (including the first evaporator 31 and the second evaporator 32), the flow direction of the refrigerant can be controlled so that it flows through the evaporator 3 in the opposite direction to the refrigeration mode, so that the defrosting circuit can share some piping with the refrigeration circuit.

[0038] Specifically, the aforementioned system circuit also includes a third pipe 14 and a fourth pipe 15 disposed between the compressor 1 and the condenser 2. The side of the third pipe 14 furthest from the exhaust outlet of the compressor 1 can be connected to the refrigeration outlet of the first evaporator 31, while the fourth pipe 15 can be connected to the refrigeration outlet of the second evaporator 32.

[0039] It is understandable that the high-temperature and high-pressure gaseous refrigerant discharged by compressor 1 can either enter the first evaporator 31 in reverse (compared to the cooling mode) along the third pipe 14 and release heat in the first evaporator 31 to melt the frost layer, or enter the second evaporator 32 in reverse (compared to the cooling mode) along the fourth pipe 15 and release heat in the second evaporator 32 to melt the frost layer.

[0040] Therefore, at this time, the refrigeration inlet of evaporator 3 can constitute its defrost outlet, and its refrigeration outlet can correspondingly constitute its defrost inlet.

[0041] Based on this, please refer to Figure 2 For the first evaporator 31, in defrost mode, when the high-temperature and high-pressure gaseous refrigerant discharged by the compressor 1 enters the first evaporator 31 in reverse, the high-temperature and high-pressure gaseous refrigerant releases heat and condenses into liquid. The liquid refrigerant can flow to the first pipeline 4 along the parallel pipeline of the first evaporator 31.

[0042] Similarly, please see Figure 3 For the second evaporator 32, in defrost mode, when the high-temperature and high-pressure gaseous refrigerant discharged by the compressor 1 enters the second evaporator 32 in reverse, the high-temperature and high-pressure gaseous refrigerant releases heat and condenses into liquid. The liquid refrigerant can also flow to the first pipeline 4 along the parallel pipeline of the second evaporator 32.

[0043] It should be noted that, to avoid temperature fluctuations inside the environmental test chamber due to defrosting, in practical applications, when one of the first evaporator 31 and the second evaporator 32 is in defrosting mode or standby mode, the other evaporator 3 can be set to cooling mode. This allows both evaporators 3 to be in defrosting mode simultaneously, ensuring the stability of the environment test chamber.

[0044] For example, in one implementation scenario, please refer to Figure 1 The first evaporator 31 and the second evaporator 32 mentioned above are in defrost mode and cooling mode, respectively.

[0045] At this time, since the second evaporator 32 is in refrigeration mode, part of the refrigerant discharged by the compressor 1 will flow into the second evaporator 32 through the condenser 2 along the first circuit b mentioned above, thereby realizing the refrigeration cycle.

[0046] As for the first evaporator 31, another part of the high-temperature and high-pressure gaseous refrigerant discharged by the compressor 1 can enter the first evaporator 31 in reverse along the third pipeline 14, and condense into liquid refrigerant after releasing heat. The liquid refrigerant can flow to the first pipeline 4 along the above-mentioned parallel pipeline of the first evaporator 31.

[0047] In the first pipeline 4, the liquid refrigerant from the first evaporator 31 after defrosting can merge with the liquid refrigerant from the condenser 2 and enter the second evaporator 32 together. After completing the refrigeration, it can return to the suction port of the compressor 1 along the second circuit b, realizing the circulation of refrigerant.

[0048] Similarly, when the first evaporator 31 is in cooling mode and the second evaporator 32 is in defrosting mode, the refrigerant circulation method can be the same as the previous case, and will not be repeated here.

[0049] Based on this, for the first evaporator 31, in defrost mode, the high-temperature, high-pressure gaseous refrigerant can enter the first evaporator 31 in reverse along the third pipe 14, and after defrosting, flow into the first pipe 4, and finally return to the compressor 1 along the refrigeration circuit of the second evaporator 32, thus realizing the defrost cycle. The system circuit that realizes this defrost cycle can constitute the second circuit a mentioned above.

[0050] Similarly, for the second evaporator 32, in defrost mode, the high-temperature, high-pressure gaseous refrigerant can enter the second evaporator 32 in reverse along the fourth pipe 15, and after defrosting, flow into the first pipe 4, and finally return to the compressor 1 along the refrigeration circuit of the first evaporator 31, thus realizing the defrost cycle. The system circuit that realizes this defrost cycle constitutes the second circuit b mentioned above.

[0051] Please see Figure 2-3 The system circuit may also include a solenoid valve d64 and a regulating valve a81 installed on the third pipeline 14, and a solenoid valve e65 and a regulating valve b82 installed on the fourth pipeline 15.

[0052] Among them, the solenoid valve d64 and the regulating valve a81 can be sequentially installed between the exhaust outlet of the compressor 1 and the defrost inlet of the first evaporator 31. The solenoid valve d64 can control the opening or closing of the third pipeline 14, while the regulating valve a81 can control the flow rate of the high-temperature and high-pressure gaseous refrigerant flowing into the first evaporator 31 during defrosting.

[0053] Similarly, the aforementioned solenoid valve e65 and regulating valve b82 can be sequentially installed between the exhaust outlet of compressor 1 and the defrost inlet of the second evaporator 32. Solenoid valve e65 can control the opening or closing of the fourth pipeline 15, while regulating valve b82 can control the flow rate of the high-temperature and high-pressure gaseous refrigerant flowing into the second evaporator 32 during defrosting.

[0054] Understandably, when one evaporator 3 is in defrost mode and the other evaporator 3 is in cooling mode, taking the first evaporator 31 in defrost mode and the second evaporator 32 in cooling mode as an example, solenoid valve b62 can be closed and solenoid valve d64 can be opened.

[0055] Thus, of the high-temperature, high-pressure gaseous refrigerant discharged by compressor 1, a portion of the refrigerant can enter the first evaporator 31 along the third pipeline 14, while the other portion of the refrigerant can flow normally to the condenser 2 and work with the second evaporator 32 to achieve refrigeration.

[0056] When the first evaporator 31 is in cooling mode and the second evaporator 32 is in defrosting mode, the refrigerant flow can be controlled in a similar way, which will not be elaborated here.

[0057] In one implementation, when the first evaporator 31 and the second evaporator 32 are both in cooling mode, the first circuit a and the first circuit b can be opened simultaneously, and the solenoid valves d64 and e65 can be closed, so that the third pipe 14 and the fourth pipe 15 are kept closed, thereby realizing the refrigerant cooling cycle.

[0058] Of course, in the system design, it is preferable that the cooling performance of a single evaporator 3 can meet the cooling requirements of the environmental test chamber. This allows the two evaporators 3 to alternate between cooling and defrosting in actual operation, which can avoid temperature fluctuations in the environmental test chamber and also avoid severe frosting on a single evaporator 3.

[0059] It should be noted that in defrost mode, the refrigerant discharged from evaporator 3 needs to flow to the first pipe 4 and merge with the refrigerant from condenser 2. However, the refrigerant discharged after defrosting will experience a large pressure drop when it flows through the throttling valve 7 in the corresponding circuit (i.e., the throttling valve 7 in the defrost circuit). This causes the refrigerant to flash before flowing into another throttling valve 7 (i.e., the throttling valve 7 in the refrigeration circuit). The bubbles generated by the flashing will occupy the internal flow channel space of the latter throttling valve 7, reducing the effective flow area, thereby reducing the valve capacity of the throttling valve 7 in the refrigeration circuit and affecting its working performance.

[0060] In response to the above situation, please refer to one embodiment. Figure 1 The system circuit is also equipped with solenoid valves f66 and g67, which can be installed on parallel pipelines connected to the first evaporator 31 and the second evaporator 32, respectively.

[0061] Specifically, such as Figure 2 As shown, taking the first evaporator 31 as an example, it is connected between the first pipeline 4 and the second pipeline 5 through corresponding parallel pipelines. For ease of description, the corresponding parallel pipeline can be referred to as the main pipeline 16, and the throttle valve a71 and the solenoid valve b62 are both installed on the main pipeline 16, and are located on both sides of the first evaporator 31 respectively.

[0062] In the cooling mode, the refrigerant can flow into the first evaporator 31 through the main pipe 16 to achieve cooling; while in the defrosting mode, the main pipe 16 can also form the refrigerant discharge pipe of the first evaporator 31, and the refrigerant discharged after defrosting can flow along the main pipe 16 to the first pipe 4.

[0063] Based on this, in order to avoid the above-mentioned flash phenomenon, a bypass pipe 17 is connected to the main pipe 16. The two ends of the bypass pipe 17 are connected to the pipes on the inlet and outlet sides of the throttle valve a71, respectively, and the above-mentioned solenoid valve f66 is also installed on the bypass pipe 17.

[0064] Thus, when the solenoid valve f66 is in the open state, the bypass pipe 17 is open, which can have a similar "short circuit" effect on the throttle valve a71 on the main pipe 16, so that the refrigerant discharged after the first evaporator 31 defrosts can bypass the throttle valve 7 along the bypass pipe 17 and flow to the first pipe 4, thereby avoiding the pressure drop caused by the throttle valve a71.

[0065] It is understandable that the second evaporator 32 can also be configured with the corresponding main pipe 16, bypass pipe 17, throttle valve b72 and solenoid valve g67 in the same manner as described above, which will not be elaborated here.

[0066] In one embodiment, please refer to Figure 1 To accurately determine when the evaporator 3 needs to be defrosted, the defrosting system may also include two first temperature sensors 9 and at least one second temperature sensor 10.

[0067] The two first temperature sensors 9 can be respectively installed on the first evaporator 31 and the second evaporator 32, and can be used to monitor the surface temperature of the first evaporator 31 and the second evaporator 32. The second temperature sensor 10 can be installed at any position inside the environmental test chamber as needed, so as to facilitate monitoring the internal temperature of the environmental test chamber.

[0068] Based on this, such as Figure 4 As shown, the defrosting system may also include a control module 11, which may be a PLC module or a matching industrial computer, without specific limitations. The control module 11 can be electrically connected to the two first temperature sensors 9, the second temperature sensor 10, and the aforementioned valves (such as the various solenoid valves 6 and the two regulating valves 8, etc.) via wired or wireless means.

[0069] In the above manner, the two first temperature sensors 9 and the second temperature sensor 10, together with the control module 11, can monitor the surface temperature of the first evaporator 31 and the second evaporator 32, as well as the internal temperature of the environmental test chamber, in real time.

[0070] Based on the surface temperature of the evaporator 3 and the internal temperature of the environmental test chamber (equivalent to the ambient temperature), combined with the principle of frosting, the control module 11 can control the relevant valves to complete the corresponding actions when the surface temperature of the evaporator 3 meets the corresponding preset conditions, so as to realize the switching of the working mode of the evaporator 3.

[0071] It is understandable that, since the control module 11 can not only control the opening or closing of each solenoid valve 6, but also control the opening degree of regulating valve a81 and regulating valve b82, for any evaporator 3, the control module 11 can control the refrigerant flow of the corresponding evaporator 3 in defrost mode by controlling the opening degree of the corresponding regulating valve 8. The input amount of refrigerant (high temperature and high pressure gaseous refrigerant) in defrost mode will affect the defrost effect of the corresponding evaporator 3.

[0072] In one embodiment, please refer to Figure 2 Taking the first evaporator 31 as an example, in order to efficiently control the opening of the regulating valve a81, a third temperature sensor 12 is installed at the defrost outlet of the first evaporator 31, while a pressure sensor 13 is installed at the refrigerant outlet of the condenser 2. Both the third temperature sensor 12 and the pressure sensor 13 can be electrically connected to the control module 11 mentioned above via wired or wireless means.

[0073] In the above manner, the third temperature sensor 12, in conjunction with the control module 11, can monitor the temperature of the refrigerant discharged after the first evaporator 31 defrosts in real time, while the pressure sensor 13, in conjunction with the control module 11, can monitor the pressure at the refrigerant outlet of the condenser 2 in real time.

[0074] Similarly, such as Figure 3 As shown, a third temperature sensor 12 can also be installed at the defrost outlet of the second evaporator 32. The third temperature sensor 12 can work with the control module 11 to monitor the temperature of the refrigerant discharged after the second evaporator 32 defrosts in real time.

[0075] Understandably, taking the first evaporator 31 as an example, in defrost mode, the amount of high-temperature, high-pressure gaseous refrigerant entering the first evaporator 31 should not be too much or too little. If too little high-temperature, high-pressure gaseous refrigerant enters the first evaporator 31, the heat released by the refrigerant will be less, affecting the defrost efficiency, and the utilization rate of the frost layer's cold storage will also be low.

[0076] If there is too much high-temperature, high-pressure gaseous refrigerant entering the first evaporator 31, the refrigerant discharged during the defrosting of the first evaporator 31 will contain gaseous refrigerant. This gaseous refrigerant flows into the second evaporator 32, where it may cool and form liquid refrigerant and accumulate there. This could result in the compressor 1 drawing in liquid refrigerant through the second pipe 5.

[0077] Since compressor 1 is not allowed to suck liquid, as this could damage the components inside compressor 1, compressor 1 is generally not allowed to suck liquid. Therefore, in practical applications, it is preferable to control the input of high-temperature, high-pressure gaseous refrigerant into the first evaporator 31 or the second evaporator 32 during defrosting within a suitable range, so as to avoid compressor 1 sucking liquid while ensuring the defrosting efficiency of evaporator 3.

[0078] It should be noted that, taking the case where the first evaporator 31 is in defrost mode and the second evaporator 32 is in refrigeration mode as an example, in order to make full use of the cold storage capacity of the frost layer in the first evaporator 31 and to avoid the compressor 1 from sucking liquid, it is necessary to ensure that all the refrigerant at the defrost outlet of the first evaporator 31 is liquefied.

[0079] Meanwhile, it is known that the refrigerant discharged by the condenser 2 during normal operation should be all liquid refrigerant, and the pressure value at the refrigerant outlet of the condenser 2 can be monitored and obtained by the pressure sensor 13. Based on the physicochemical properties of the corresponding refrigerant, the saturation temperature of the refrigerant at the corresponding pressure can be obtained.

[0080] Thus, the refrigerant flow rate during defrosting of the first evaporator 31 can be adjusted by controlling the opening of the regulating valve a81, thereby changing the temperature of the defrosting outlet of the first evaporator 31.

[0081] While keeping the refrigerant type unchanged, PID control can be implemented based on the saturation temperature corresponding to the pressure at the refrigerant outlet of condenser 2. The PID control object can be the temperature of the defrost outlet of the first evaporator 31, with the control objective being to reach the aforementioned saturation temperature at the defrost outlet. Alternatively, the temperature of the defrost outlet can be controlled to be lower than the aforementioned saturation temperature, for example, by setting a subcooling setting of 2°C. Even if the temperature of the defrost outlet is 2°C lower than the aforementioned saturation temperature, a certain subcooling setting is preferred to ensure that all the refrigerant at the defrost outlet is liquefied.

[0082] Similarly, when the first evaporator 31 is in cooling mode and the second evaporator 32 is in defrost mode, the opening of the regulating valve b82 can be controlled in the same way, which will not be elaborated here.

[0083] It should be noted that, in this embodiment of the invention, the solenoid valves b62 and c63 described above can constitute first solenoid valves. These two first solenoid valves are essentially respectively disposed on first circuit a and first circuit b, and can be used to control the opening or closing of first circuit a and first circuit b, respectively. Simultaneously, the solenoid valves d64 and e65 described above can constitute second solenoid valves. These two second solenoid valves are essentially respectively disposed on second circuit a and second circuit b, and can be used to control the opening or closing of second circuit a and second circuit b, respectively. By controlling the operating states of the two first solenoid valves and the two second solenoid valves, the switching of the operating circuits of the first evaporator 31 and the second evaporator 32 can be achieved, thereby switching their operating modes.

[0084] Meanwhile, in this embodiment of the invention, in order to avoid temperature fluctuations inside the environmental test chamber, the defrosting system is equipped with at least two evaporators 3, but this does not mean that the evaporators 3 can only be set to two.

[0085] For example, in some embodiments, there may be three or more evaporators 3. In this case, the two circuits (i.e., the first circuit and the second circuit) corresponding to each evaporator 3 can be set with reference to the two circuits of the first evaporator 31 mentioned above.

[0086] Thus, the operating mode of any evaporator 3 can be switched between cooling mode, defrosting mode and standby mode. It can be ensured that when there is an evaporator 3 in the system in defrosting mode, at least one of the evaporators 3 can be set to cooling mode. Its working principle has not changed, so it will not be described in detail here.

[0087] In this embodiment, the valves can be a combination of solenoid valve 6, throttle valve 7, and regulating valve 8, but this does not mean that only this combination can achieve the same technical effect. In other embodiments, other valve types can be used to achieve the same technical effect according to functional requirements, and no specific limitation is made in this regard.

[0088] Furthermore, in this embodiment, there are two evaporators 3, and the two evaporators 3 are connected in parallel between the first pipe 4 and the second pipe 5. However, this does not mean that the defrosting system can only adopt this parallel system loop structure.

[0089] For example, in some embodiments, while ensuring that each evaporator 3 has a corresponding first circuit and second circuit, and can freely switch between multiple operating modes, corresponding circuits can also be set for the two evaporators 3 as needed, and the circuits corresponding to each evaporator 3 can remain independent of each other.

[0090] Please see Figure 5The present invention also provides a defrosting method for an environmental test chamber, which can be applied to the above-mentioned defrosting system for an environmental test chamber.

[0091] As described above regarding the composition of the defrosting system, the defrosting system has at least two evaporators 3. Even if there are two or more evaporators 3, the defrosting principle of the system remains unchanged. Therefore, to facilitate understanding of the defrosting method in this embodiment, we will take the case of having two evaporators 3 as an example to specifically introduce one implementation of the defrosting method. However, this does not mean that the defrosting method is only applicable to the case of having two evaporators 3.

[0092] Please see Figure 5-6 The defrosting method for this environmental test chamber may include the following steps: Determine the frosting condition of each evaporator 3; Based on the frosting condition of each evaporator 3, determine whether each evaporator 3 has met the preset defrosting conditions; Based on the determined results, adjust the operating mode of each evaporator 3 in the system accordingly; Specifically, for evaporators 3 whose frosting conditions meet the preset conditions, their operating mode is adjusted to defrosting mode; for evaporators 3 whose frosting conditions do not meet the preset conditions, at least one of the evaporators 3 is set to cooling mode.

[0093] Specifically, when determining the frosting condition of each evaporator 3, the thickness of the frosting on each evaporator 3 can be judged by the surface temperature of each evaporator 3 and the internal temperature of the environmental test chamber (i.e., the ambient temperature).

[0094] Taking the case where there are two evaporators 3 as an example, since both the first evaporator 31 and the second evaporator 32 are equipped with first temperature sensors 9, the two first temperature sensors 9 can work with the control module 11 to monitor the surface temperature of the first evaporator 31 and the second evaporator 32 in real time. At the same time, the second temperature sensor 10 installed inside the environmental test chamber can also be used to monitor the internal temperature of the environmental test chamber in real time.

[0095] After obtaining the surface temperature of the evaporator 3 and the internal temperature of the environmental test chamber, based on the frosting principle, preset conditions can be set in the control module 11 so that the control module can automatically start the defrosting program when the surface temperature of the evaporator 3 meets the preset defrosting conditions, so as to defrost the corresponding evaporator 3.

[0096] For example, in one embodiment, please refer to Figure 6Based on the principle of frosting, the preset conditions for defrosting may include: first, the surface temperature of the evaporator 3 is lower than the specified temperature; second, the surface temperature of the evaporator 3 is lower than the internal temperature of the environmental test chamber, and the temperature difference is greater than the preset temperature difference; third, the duration of the former condition is greater than the preset duration.

[0097] In practical applications, based on the principle of frosting, the specified temperature mentioned above can be 0℃. That is, for any evaporator 3, the first condition for triggering the defrosting program can be that the surface temperature of the evaporator 3 is below 0℃.

[0098] In cooling mode, evaporator 3 is a component that directly cools, and its surface temperature is bound to be lower than the internal temperature of the environmental test chamber. At this time, if the surface temperature of evaporator 3 is lower than the internal temperature of the environmental test chamber, and the temperature difference reaches the preset temperature difference, the second condition for triggering the defrosting program can be activated.

[0099] Under the premise of triggering the above two conditions for the defrosting program, in order to avoid the defrosting program being accidentally triggered due to temporary temperature fluctuations of the evaporator 3, when the surface temperature of the evaporator 3 meets the above two triggering conditions at the same time, it can be further determined whether to start the defrosting program based on the duration of the condition triggering.

[0100] Specifically, when the surface temperature of the evaporator 3 is lower than the internal temperature of the environmental test chamber, and the temperature difference between the two is greater than the preset temperature difference, if the duration of this situation is greater than the preset duration, it can be determined that the frost on the corresponding evaporator 3 has thickened and defrosting is required, that is, the evaporator 3 has met the preset defrosting conditions.

[0101] It should be noted that the preset temperature difference and preset duration can be flexibly set as needed. For example, in one implementation scenario, the preset temperature difference can be set to 2℃, 3℃, 4℃, 5℃ or other values, and the preset duration can be set to 2s, 3s, 4s, 5s or other durations. There are no specific limitations on these.

[0102] After determining the frosting condition of the evaporator 3, the control module 11 can switch the working circuit of the evaporator 3 by controlling the working state of various valves (such as solenoid valve 6, throttle valve 7 and regulating valve 8, etc.) and make the evaporator 3 switch to the required working mode (which may include at least cooling mode, defrosting mode and standby mode).

[0103] In one typical operating scenario, the first evaporator 31 and the second evaporator 32 can alternate between cooling and defrosting. That is, when the first evaporator 31 is defrosting, the second evaporator 32 can be in cooling mode; when the second evaporator 32 is defrosting, the first evaporator 31 can be in cooling mode.

[0104] Specifically, taking one implementation scenario under this operating condition as an example, the first evaporator 31 is currently cooling, and the second evaporator 32 is defrosting. Assuming that the surface temperature of the first evaporator 31 meets the aforementioned preset defrosting conditions, and the second evaporator 32 no longer needs defrosting, the first evaporator 31 can be switched from cooling mode to defrosting mode, and the second evaporator 32 can be switched from defrosting mode to cooling mode simultaneously.

[0105] In the current situation, the operating circuit of the first evaporator 31 is the first circuit a, and the operating circuit of the second evaporator 32 is the second circuit b. To achieve the above-mentioned mode switching, the operating circuit of the first evaporator 31 needs to be switched to the second circuit a, and the operating circuit of the second evaporator 32 needs to be switched to the first circuit b.

[0106] Therefore, for the first evaporator 31, the control module 11 can control the solenoid valve b62 to close and the solenoid valves d64 and f66 to open, thereby switching the working circuit of the first evaporator 31 from the first circuit a to the second circuit a, so that the first evaporator 31 switches to the defrost mode.

[0107] Meanwhile, for the second evaporator 32, the control module 11 can control the solenoid valves e65 and g67 to close and the solenoid valve c63 to open, thereby switching the working circuit of the second evaporator 32 from the second circuit b to the first circuit b, so that the second evaporator 32 switches to the cooling mode.

[0108] Understandably, based on the structure in which the first evaporator 31 and the second evaporator 32 are connected in parallel between the third pipe 14 and the fourth pipe 15, when the first evaporator 31 switches to defrost mode and the second evaporator 32 switches to refrigeration mode, part of the high-temperature and high-pressure gaseous refrigerant discharged by the compressor 1 can enter the first evaporator 31 through the third pipe 14 and defrost the first evaporator 31, while the other part can flow along the second circuit b to refrigerate the second evaporator 32.

[0109] During this process, the flow direction of the refrigerant in the first evaporator 31 will change. That is, compared with the cooling mode, in the defrosting mode, the refrigerant will flow in the reverse direction through the first evaporator 31 and through the corresponding main pipeline 16 to the first pipeline 4, and then merge with the refrigerant from the condenser 2 and enter the second evaporator 32 together, and finally return to the compressor 1 along the second pipeline 5 to complete one cycle.

[0110] In one embodiment, when defrosting one of the evaporators 3, the defrosting method may further include the following steps: Obtain the pressure value at the condenser outlet; Real-time monitoring of the temperature at the defrost outlet of the evaporator; Adjust the refrigerant flow rate during evaporator defrosting until the temperature reaches the saturation temperature corresponding to the pressure value, or is lower than the saturation temperature and the temperature difference reaches the specified temperature difference.

[0111] Specifically, the pressure sensor 13, located at the refrigerant outlet of the condenser 2, works in conjunction with the control module 11 to monitor and acquire the pressure value at the outlet of the condenser 2. Simultaneously, the third temperature sensor 12, located at the defrost outlet of any evaporator 3, also works in conjunction with the control module 11 to monitor the temperature value at the defrost outlet of the corresponding evaporator 3 during defrosting.

[0112] Taking the case where the first evaporator 31 is in defrost mode and the second evaporator 32 is in refrigeration mode as an example, it is known that the refrigerant discharged by the condenser 2 during normal operation should be liquid refrigerant, and the pressure value at the refrigerant outlet of the condenser 2 can be monitored and obtained through the pressure sensor 13. Based on the physicochemical properties of the corresponding refrigerant, the saturation temperature of the refrigerant at the corresponding pressure can be obtained.

[0113] Thus, by controlling the opening of regulating valve a81, the flow rate of the high-temperature, high-pressure gaseous refrigerant entering the first evaporator 31 for defrosting can be adjusted, thereby changing the temperature of the defrosting outlet of the first evaporator 31.

[0114] Meanwhile, while keeping the refrigerant type unchanged, PID control can be implemented based on the saturation temperature corresponding to the pressure at the refrigerant outlet of condenser 2. The PID control object can be the temperature at the defrost outlet of the first evaporator 31, and the control target can be that the temperature at the defrost outlet meets a specified condition. This specified condition can be flexibly set as needed to ensure that the temperature at the defrost outlet reaches the desired value.

[0115] In one embodiment, when performing the above-mentioned PID control, the PID control object can be the temperature of the defrost outlet of the first evaporator 31, and the control target can be that the temperature of the defrost outlet meets the above-mentioned saturation temperature (i.e., the saturation temperature corresponding to the pressure at the outlet of the condenser 2), or the temperature of the defrost outlet can be controlled to be lower than the saturation temperature. For example, a subcooling setting of 2°C can be set. Even if the temperature of the defrost outlet is lower than the above-mentioned saturation temperature by 2°C, and preferably a certain subcooling setting is adopted to ensure that all the refrigerant at the defrost outlet is liquefied.

[0116] Similarly, when the first evaporator 31 is in cooling mode and the second evaporator 32 is in defrosting mode, the opening of the regulating valve b82 can be controlled in the same way to regulate the refrigerant flow during defrosting of the second evaporator 32. The specific adjustment method is as described above and will not be repeated here.

[0117] After one of the evaporators 3 begins defrosting, as high-temperature, high-pressure gaseous refrigerant continues to enter the evaporator 3 and releases heat, the frost layer inside the evaporator 3 will continue to melt, and the high-temperature, high-pressure gaseous refrigerant can condense into liquid refrigerant. As the frost layer decreases, the surface temperature of the evaporator 3 will begin to rise, allowing the evaporator 3 to recover its cooling performance.

[0118] In this embodiment, please refer to Figure 6 For evaporator 3 that is currently defrosting, to facilitate determining when evaporator 3 should exit defrosting mode, the defrosting method may also include the following steps: Real-time monitoring of surface temperature changes during defrosting of evaporator 3; Based on the change in surface temperature of evaporator 3, determine whether evaporator 3 meets the preset conditions for exiting defrost mode; Based on the judgment result, maintain the defrost mode of evaporator 3, or control evaporator 3 to exit the defrost mode.

[0119] Specifically, using the first temperature sensor 9 installed on the evaporator 3, in conjunction with the control module 11, the change in surface temperature of the evaporator 3 during defrosting can be monitored in real time. Based on the change in surface temperature of the evaporator 3 during defrosting, combined with the corresponding preset conditions, it can be determined whether the evaporator 3 has completed defrosting; after determining that the evaporator 3 has completed defrosting, the evaporator 3 can be controlled to exit the defrosting mode.

[0120] The preset conditions used to determine whether the evaporator 3 can exit the defrost mode can be flexibly set as needed. For example, in one implementation, the preset condition can be: the surface temperature of the evaporator 3 is greater than or equal to the set temperature, and the duration reaches the set time.

[0121] At this time, the set temperature and set duration can be flexibly set as needed. For example, the set temperature can be set to 5℃ and the set duration can be set to 5s. In this way, when the surface temperature of the evaporator 3 reaches 5℃ or above during defrosting and the duration exceeds 5s, it can be determined that the evaporator 3 has met the conditions for exiting the defrosting mode.

[0122] When the evaporator 3 is determined to meet the conditions for exiting the defrost mode, the control module 11 can switch the evaporator 3 to cooling mode by switching its operating circuit, or it can simultaneously shut down the two circuits corresponding to the evaporator 3 (i.e., the first circuit and the second circuit) to keep it in standby mode. The specific choice can be made as needed. The specific switching method for the operating mode of any evaporator 3 can be referred to the relevant descriptions above, and will not be repeated here.

[0123] In this embodiment, when the internal temperature of the environmental test chamber is low, multiple evaporators 3 may simultaneously meet the preset defrosting conditions. For this situation, please refer to [link / reference needed]. Figure 6 The defrosting method may also include the following steps: Obtain the surface temperature of each evaporator; Based on the surface temperature of each evaporator, the evaporators are ordered for defrosting. Based on the above defrosting sequence, control each evaporator to perform alternating defrosting cycles until each evaporator no longer meets the preset defrosting conditions.

[0124] Specifically, by using the first temperature sensor 9 installed on each evaporator 3, in conjunction with the control module 11, the surface temperature of each evaporator 3 can be monitored and acquired in real time.

[0125] Based on this, the control module 11 can compare the numerical values ​​of the surface temperatures of each evaporator 3 (since the temperature must be below 0°C when defrosting is triggered, the absolute value can be taken). Since the larger the value, the lower the surface temperature of the corresponding evaporator 3, which means that its frost layer is theoretically thicker, the defrosting order of each evaporator 3 can be sorted according to the numerical values ​​of the surface temperatures of each evaporator 3.

[0126] After determining the defrosting sequence, the control module 11 can control each evaporator 3 to defrost alternately according to the defrosting sequence, as follows: Taking the case where there are two evaporators 3 as an example, assuming that the surface temperature of the first evaporator 31 is lower than the surface temperature of the second evaporator 32, the defrosting sequence is as follows: the first evaporator 31 is defrosted first, the second evaporator 32 is defrosted later, and then the two alternately defrost in turn.

[0127] When the first evaporator 31 starts defrosting, by monitoring the change in the surface temperature of the first evaporator 31 in real time, when the surface temperature of the first evaporator 31 meets the preset conditions for exiting the defrosting mode, the control module 11 can close the defrosting circuit of the first evaporator 31 and open the defrosting circuit of the second evaporator 32, so that the second evaporator 32 enters the defrosting mode.

[0128] When the second evaporator 32 starts defrosting, by monitoring the change in the surface temperature of the second evaporator 32 in real time, when the surface temperature of the second evaporator 32 meets the preset conditions for exiting the defrosting mode, the control module 11 can close the defrosting circuit of the second evaporator 32 and reopen the defrosting circuit of the first evaporator 31, so that the first evaporator 31 re-enters the defrosting mode.

[0129] After that, the above steps can be repeated until the first evaporator 31 and the second evaporator 32 no longer trigger the preset conditions of the defrosting program, and the normal working state of the defrosting system can be restored. That is, at least one of the multiple evaporators 3 is in the cooling mode, while the other evaporators 3 can be in the cooling mode, the defrosting mode, or the standby mode. The specific settings can be set as needed, and no specific limitation is made.

[0130] It should be noted that the defrosting method provided in this embodiment can overcome the problems of large temperature fluctuations, high energy consumption, and unreliable defrosting during the operation of the environmental test chamber. It allows the environmental test chamber to operate without stopping during defrosting, thereby reducing temperature fluctuations inside the chamber, ensuring the stability of test results, enhancing the reliability of the refrigeration system during defrosting, reducing energy consumption, and avoiding liquid suction damage to the compressor 1.

[0131] In this embodiment, by arranging multiple evaporators 3 in parallel, defrosting without stopping the system can be achieved, reducing temperature fluctuations during defrosting. Based on the pressure at the outlet of the condenser 2 and the temperature at the defrost outlet of the evaporator 3, the amount of hot gas injected into the evaporator 3 can be precisely controlled, preventing excessive liquid condensation of the refrigerant from causing liquid carryover in the compressor 1, thereby improving the reliability of the system operation.

[0132] In addition, by reasonably controlling the temperature of the defrost outlet of the evaporator 3, it can achieve the same or similar condensing effect as the condenser 2, thereby recovering the cooling capacity generated when the frost melts, which helps to reduce energy consumption.

[0133] In the description of this application, it should be noted that the terms "upper" and "lower," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0134] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0135] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A defrosting system for an environmental test chamber, characterized in that, include: A compressor is used to compress refrigerant and drive its flow. A condenser, connected to the exhaust outlet of the compressor, is used to condense the refrigerant; At least two evaporators, each with a cooling mode and a defrosting mode; Multiple first loops, each corresponding to a specific evaporator, are provided. Each first loop is connected to the compressor, the condenser, and the corresponding evaporator, and is configured as the refrigeration loop for that evaporator. Multiple second loops, each corresponding to a different evaporator, are provided. Each second loop is connected to the compressor and the corresponding evaporator and is configured as the defrosting loop for the corresponding evaporator. The refrigerant output from the compressor flows along any first loop, passes through the condenser into the corresponding evaporator, and returns to the compressor, thus realizing the refrigeration cycle of the corresponding evaporator; the refrigerant output from the compressor circulates between the compressor and the corresponding evaporator along any second loop, thus realizing the defrosting cycle of the corresponding evaporator; when an evaporator is in defrosting mode, at least one evaporator is in refrigeration mode.

2. The defrosting system for an environmental test chamber according to claim 1, characterized in that, The defrost outlet of any of the evaporators is connected to the refrigeration inlet of other evaporators via a pipeline, so that the refrigerant discharged during defrosting of any of the evaporators can enter other evaporators in refrigeration mode and participate in the refrigeration cycle of the evaporators in refrigeration mode.

3. The defrosting system for the environmental test chamber according to claim 2, characterized in that, The refrigerant flow direction of any of the evaporators is opposite in cooling mode and defrost mode; the cooling inlet of any of the evaporators is connected to a main pipeline, which connects to the cooling inlets of other evaporators when the corresponding evaporator is defrosting, and forms a refrigerant discharge pipeline when the corresponding evaporator is defrosting; a throttling valve is provided on the main pipeline, and a bypass pipeline is also connected between the inlet and outlet of the throttling valve, and a solenoid valve is provided on the bypass pipeline.

4. The defrosting system for an environmental test chamber according to claim 1, characterized in that, The defrosting system of the environmental test chamber includes: Multiple first solenoid valves are respectively disposed on the multiple first circuits, and are used to control the opening or closing of the corresponding first circuit; Multiple second solenoid valves are respectively disposed on the multiple second circuits, and are used to control the opening or closing of the corresponding second circuit; and The control module is electrically connected to the plurality of first solenoid valves and the plurality of second solenoid valves respectively, and is used to realize automatic control.

5. The defrosting system for an environmental test chamber according to claim 4, characterized in that, The defrosting system of the environmental test chamber also includes: Multiple regulating valves are respectively installed on the multiple second circuits and located between the exhaust outlet of the compressor and the defrost inlet of the corresponding evaporator. The multiple regulating valves are all electrically connected to the control module and are used to regulate the defrost flow rate of the corresponding evaporator.

6. The defrosting system for an environmental test chamber according to claim 4, characterized in that, The defrosting system of the environmental test chamber also includes: Multiple first temperature sensors are respectively installed on each evaporator and electrically connected to the control module, respectively used to monitor the surface temperature of the corresponding evaporator; and The second temperature sensor is installed inside the environmental test chamber and electrically connected to the control module to monitor the temperature inside the environmental test chamber.

7. The defrosting system for an environmental test chamber according to claim 4, characterized in that, The defrosting system of the environmental test chamber also includes: Multiple third temperature sensors are respectively installed at the defrost outlet of each evaporator and electrically connected to the control module, respectively used to monitor the temperature at the defrost outlet of each evaporator; and A pressure sensor is installed at the refrigerant outlet of the condenser and electrically connected to the control module to monitor the pressure at the refrigerant outlet of the condenser.

8. A defrosting method for an environmental test chamber, characterized in that, The defrosting system for an environmental test chamber as described in any one of claims 1-7 comprises the following steps: Determine the frosting condition of each evaporator; Based on the frosting condition of each evaporator, determine whether each evaporator has met the preset defrosting conditions; Based on the determined results, adjust the operating mode of each evaporator in the system accordingly; Specifically, for evaporators whose frosting conditions meet the preset conditions, their operating mode is adjusted to defrost mode; for evaporators whose frosting conditions do not meet the preset conditions, at least one of the evaporators is set to cooling mode.

9. The defrosting method for an environmental test chamber according to claim 8, characterized in that, When defrosting one of the evaporators, the environmental test chamber defrosting method further includes: Obtain the pressure value at the condenser outlet; Real-time monitoring of the temperature at the defrost outlet of the evaporator; Adjust the refrigerant flow rate during evaporator defrosting until the temperature reaches the saturation temperature corresponding to the pressure value, or is lower than the saturation temperature and the temperature difference reaches the specified temperature difference.

10. The defrosting method for an environmental test chamber according to claim 8, characterized in that, When the frosting conditions of multiple evaporators simultaneously meet the preset defrosting conditions, the environmental test chamber defrosting method further includes: Obtain the surface temperature of each evaporator; Based on the surface temperature of each evaporator, the evaporators are ordered for defrosting. According to the defrosting sequence, each evaporator is controlled to perform alternating defrosting until each evaporator no longer meets the preset defrosting conditions.

Images