An environmental test system capable of synchronous testing and a control method thereof

Abstract

The application discloses an environment test system and a control method, which can be used for synchronous test. The system comprises a box body, a compressor, a condenser and an evaporator. One end of a first evaporator and a second evaporator connected in parallel is connected with one end of a third evaporator, and the other end is connected with an output end of the compressor in sequence through a second condenser and a first condenser. The other end of the third evaporator is connected with an input end of the compressor. The compressor is used for extracting steam from different evaporators and compressing the steam into high-temperature and high-pressure gaseous refrigerant. The first condenser is used for preheating water required by a humidity test area and a high-temperature environment area through heat release. The second condenser is used for releasing heat absorbed in each low-temperature test area to the outside. The refrigerant in the first evaporator and the second evaporator exchanges heat with cooled objects respectively. The third evaporator is used for absorbing heat from air to preheat water required by the humidity test area and the high-temperature environment area. The application has the advantages of low cost, small occupied area, resource saving and the like.

Description

Technical Field

[0001] This invention relates to the field of environmental testing technology, specifically to an environmental testing system capable of simultaneous testing and its control method. Background Technology

[0002] Rail transit electrical and electronic products must undergo high temperature, low temperature, and alternating damp heat tests according to the relevant requirements of GB / T 2423 to verify their ability to withstand harsh natural environments in actual applications. Since locomotives and rolling stock will cross different latitudes and longitudes during operation, the operating environment of the equipment is uncertain. Before being officially installed on the train, the equipment must be exposed to an artificial environment to evaluate its performance in actual use.

[0003] Currently, commonly used environmental test chambers include high-temperature environment test chambers, low-temperature environment test chambers, and rapid temperature change environment test chambers. High-temperature environment test chambers and low-temperature environment test chambers can only simulate a single high-temperature or low-temperature environment, and their performance is too limited. Although rapid temperature change environment test chambers can conduct high-temperature, low-temperature, or alternating damp heat environment tests, they cannot be conducted simultaneously. When different equipment is required to conduct different tests, more equipment needs to be purchased, which significantly increases the testing cost and occupies a large amount of testing space.

[0004] In addition, heat will be continuously generated and transferred during the experiment. When conducting a single experiment, excess heat is usually released outdoors, which fails to make full use of resources and results in waste. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a low-cost, small-area, resource-saving environmental testing system and its control method that can be used for simultaneous testing, in response to the problems existing in the prior art.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0007] An environmental testing system capable of simultaneous testing includes a chamber, a compressor, a first condenser, a second condenser, a first evaporator, a second evaporator, and a third evaporator. The chamber is provided with a heat insulation layer to divide the chamber into multiple test zones for conducting different types of tests.

[0008] One end of the first evaporator and the second evaporator connected in parallel is connected to one end of the third evaporator, and the other end is connected to the output end of the compressor via the second condenser and the first condenser in sequence. The other end of the third evaporator is connected to the input end of the compressor.

[0009] The compressor is used to draw low-temperature, low-pressure steam from different evaporators and compress it into high-temperature, high-pressure gaseous refrigerant;

[0010] The first condenser is used to preheat the water required for the humidity test area and the high-temperature environment area by releasing heat.

[0011] The second condenser is used to release the heat absorbed in each low-temperature test zone into the outdoor air after preheating or when high-temperature and humidity tests are not required.

[0012] The low-temperature, low-pressure liquid refrigerant in the first and second evaporators exchanges heat with the objects being cooled in different low-temperature test zones, and evaporates into gaseous refrigerant by absorbing heat.

[0013] The third evaporator is used to absorb heat from the air to preheat the water required for the humidity test area and the high-temperature environment area when low-temperature testing is not required.

[0014] Preferably, the system further includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, a fifth solenoid valve, a sixth solenoid valve, a seventh solenoid valve, and an eighth solenoid valve. The output end of the compressor is connected to one end of the first solenoid valve and one end of the second solenoid valve, respectively. The other end of the first solenoid valve is connected to one end of the first condenser. After the other end of the first condenser is connected to the other end of the second solenoid valve, it is then connected to one end of the third solenoid valve and one end of the fourth solenoid valve, respectively. The other end of the fourth solenoid valve is connected to one end of the second condenser. After the other end of the second condenser is connected to the other end of the third solenoid valve, it is then connected to one end of the fifth solenoid valve and one end of the sixth solenoid valve, respectively. The other end of the sixth solenoid valve is connected to one end of the first evaporator and one end of the second evaporator, respectively. After the other ends of the first evaporator and the second evaporator are connected, they are then connected to one end of the seventh solenoid valve and one end of the eighth solenoid valve, respectively. The other end of the eighth solenoid valve is connected to one end of the third evaporator, and the other end of the seventh solenoid valve and the other end of the third evaporator are both connected to the input end of the compressor. The other end of the second condenser is connected to one end of the seventh solenoid valve via the fifth solenoid valve.

[0015] Preferably, it further includes a separator, a first electronic expansion valve, a second electronic expansion valve, a diversion valve, and a heat exchanger; one end of the first evaporator is connected to the separator in sequence via the first electronic expansion valve and the diversion valve, and the separator is connected to one end of the second evaporator in sequence via the heat exchanger and the second electronic expansion valve; wherein the separator is used to separate the refrigerant, wherein the refrigerant is a mixture of refrigerants with different boiling points to meet the refrigeration requirements of different temperature test zones, the high-boiling-point refrigerant is diverted by the diversion valve and part of it flows directly into the first electronic expansion valve, and the other part flows into the heat exchanger to condense and absorb the heat released by the low-boiling-point gaseous refrigerant to achieve cooling; the low-boiling-point refrigerant flows into the second electronic expansion valve after being cooled by the heat exchanger, and the first electronic expansion valve and the second electronic expansion valve control the flow rate of the low-pressure low-temperature liquid refrigerant flowing into the evaporator by throttling.

[0016] Preferably, the system further includes a first pressure-temperature sensor, a second pressure-temperature sensor, a third pressure-temperature sensor, an exhaust temperature sensor, and a controller. The first pressure-temperature sensor is located at the other end of the first evaporator, the second pressure-temperature sensor is located at the other end of the second evaporator, the third pressure-temperature sensor is located at the other end of the third evaporator, and the exhaust temperature sensor is located at the output end of the compressor. The controller uses the superheat of each evaporator obtained from each pressure-temperature sensor as the main feedback control signal and the exhaust temperature of the exhaust temperature sensor as the auxiliary control signal to achieve dual feedback fuzzy control of each electronic expansion valve.

[0017] The present invention also discloses a control method for an environmental testing system based on the above-described synchronous testing method, comprising:

[0018] The pressure and temperature signals of the first evaporator are obtained through the first pressure and temperature sensor; the pressure and temperature signals of the second evaporator are obtained through the second pressure and temperature sensor; the pressure and temperature signals of the third evaporator are obtained through the third pressure and temperature sensor; and the exhaust temperature of the compressor is obtained through the exhaust temperature sensor.

[0019] The controller controls the switching of each solenoid valve according to the test type;

[0020] The controller uses the superheat of each evaporator obtained from each pressure and temperature sensor as the main feedback control signal and the exhaust temperature of the exhaust temperature sensor as the auxiliary control signal to achieve dual feedback fuzzy control of each electronic expansion valve.

[0021] Preferably, when conducting environmental tests under alternating damp heat, a first low temperature condition, and a second low temperature condition simultaneously, the chamber is divided into three different test zones using a heat insulation layer. The second, fourth, fifth, and eighth solenoid valves are closed, while the first, third, sixth, and seventh solenoid valves are simultaneously opened, causing the compressor, first condenser, first evaporator, and second evaporator to work in coordination. The second condenser and third evaporator are then closed. The compressor draws away the steam generated in the first and second evaporators, compresses it into high-temperature, high-pressure steam, and discharges it. This steam releases heat in the first condenser to preheat the water and high-temperature environment zone required for the alternating damp heat test. After exothermic cooling, the mixed refrigerant flows into a separator for further cooling. In the gas-liquid separation process, the high-boiling-point refrigerant is divided into two paths by a diverter valve. One path flows directly into the first electronic expansion valve after passing through a separator. After throttling, it enters the first evaporator to evaporate and absorb heat from the object being cooled, thus cooling the low-temperature test zone. The low-boiling-point refrigerant, after being vaporized by the separator, exchanges heat with the other path of high-boiling-point liquid refrigerant in a heat exchanger. The high-boiling-point liquid refrigerant carries away the heat from the low-boiling-point refrigerant, causing it to re-liquefy and flow into the second electronic expansion valve. After throttling, it evaporates in the second evaporator and absorbs heat from the object being cooled, thus cooling the low-temperature test zone. The high-boiling-point refrigerant, after absorbing heat in the heat exchanger, re-vaporizes and is finally drawn into the compressor along with the gaseous refrigerant flowing out of the first and second evaporators, starting the next cycle.

[0022] Preferably, when environmental tests are conducted simultaneously under high temperature, first low temperature, and second low temperature conditions without humidity, the second, fourth, fifth, and eighth solenoid valves are closed, while the first, third, sixth, and seventh solenoid valves are opened simultaneously, causing the compressor, first condenser, first evaporator, and second evaporator to work together. The second condenser and third evaporator are then closed. The compressor draws away the steam generated in the first and second evaporators and compresses it into high-temperature, high-pressure steam before discharging it, so that the heat released in the first condenser is only used for preheating the high-temperature environment.

[0023] Preferably, when alternating damp heat and high temperature tests are not performed or preheating is completed, the first, third, fifth, and eighth solenoid valves are closed, and the second, fourth, sixth, and seventh solenoid valves are opened simultaneously, causing the compressor, second condenser, first evaporator, and second evaporator to work together. The first condenser and third evaporator are closed, and the high-pressure gaseous refrigerant compressed by the compressor no longer flows through the first condenser, but is cooled in the second condenser to dissipate heat to the outside.

[0024] Preferably, when only the first low-temperature test is performed, the first, third, fifth, and eighth solenoid valves are closed, while the second, fourth, sixth, and seventh solenoid valves are simultaneously opened. The compressor, second condenser, and first evaporator work together to stop the first condenser, second evaporator, and third evaporator from working. In addition, the function of the separator is turned off, and the flow divider valve is adjusted so that the mixed refrigerant flows through the separator and flow divider valve simultaneously, and then passes through the first electronic expansion valve for throttling. It evaporates and absorbs heat in the first evaporator, and after being compressed by the compressor, it releases the heat in the second condenser before entering the next refrigeration cycle.

[0025] Preferably, when only the second low-temperature test is performed, the first, third, fifth, and eighth solenoid valves are closed, while the second, fourth, sixth, and seventh solenoid valves are opened simultaneously. The compressor, second condenser, and second evaporator work together to stop the first condenser, first evaporator, and third evaporator from working. At the same time, the flow divider valve is adjusted to allow all the high-boiling-point refrigerant to flow into the heat exchanger to absorb heat and cool the low-boiling-point refrigerant. After being throttled by the second electronic expansion valve, the refrigerant evaporates and absorbs heat in the second evaporator. After being compressed by the compressor, the heat is released in the second condenser, and then the next refrigeration cycle begins.

[0026] Preferably, when only alternating damp heat test is performed, the second, fourth, sixth, and seventh solenoid valves are closed, and the second, third, fifth, and eighth solenoid valves are opened simultaneously. The compressor, the first condenser, and the third evaporator work simultaneously. The refrigerant absorbs heat from the outdoor air in the third evaporator and is then compressed into high-temperature and high-pressure steam by the compressor. The steam releases heat in the first condenser to preheat the water required for alternating damp heat and the high-temperature environment zone.

[0027] Preferably, when only high-temperature testing is performed, the second, fourth, sixth, and seventh solenoid valves are closed, while the second, third, fifth, and eighth solenoid valves are opened simultaneously. The compressor, the first condenser, and the third evaporator work simultaneously. The refrigerant absorbs heat from the outdoor air in the third evaporator and is then compressed into high-temperature, high-pressure steam by the compressor. The heat released in the first condenser is only for preheating the high-temperature environment.

[0028] Preferably, when the rate of change of superheat is large, the proportional coefficient 'a' of the influence weight of the superheat feedback signal is increased, and the proportional coefficient '1-a' of the influence weight of the corresponding exhaust temperature feedback signal decreases. In this case, the superheat signal is used as the main feedback signal to achieve the regulation of the electronic expansion valve. Conversely, when the rate of change of superheat is slow, the proportional coefficient 'a' of the influence weight of the superheat feedback signal is decreased, and the proportional coefficient '1-a' of the influence weight of the corresponding exhaust temperature feedback signal will increase significantly. In this case, the exhaust temperature signal is used as the main feedback signal to achieve rapid regulation of the electronic expansion valve.

[0029] Compared with the prior art, the advantages of the present invention are as follows:

[0030] This invention utilizes an insulation layer to divide the test chamber into several independent test zones. Through the design of the refrigeration and humidification system, environmental tests under different conditions can be conducted simultaneously within the same environmental chamber, fully realizing the exchange of various heat sources, saving resources, and allowing multiple tests to be performed from a single environmental chamber, significantly reducing costs and the space required for testing. Addressing the issue of high power load and slow response caused by heating water solely with electric heating elements in humidity tests, this invention uses a condenser to preheat the water. This fully utilizes the heat generated during equipment operation, saving resources, and also accelerates the water boiling rate, improving the response speed. Furthermore, the opening of the electronic expansion valve is controlled by two feedback parameters: superheat and exhaust temperature. The weight ratio of the two feedback signals is determined by the rate of change of superheat, and fuzzy control is used to achieve precise and rapid adjustment of the electronic expansion valve. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the housing of the present invention in an embodiment.

[0032] Figure 2 The diagrams show the internal structure of the housing according to Embodiment 1 and Embodiment 2 of the present invention.

[0033] Figure 3 This is a schematic diagram of the internal structure of the box of the present invention in Embodiment 3.

[0034] Figure 4 This is a schematic diagram of the internal structure of the box of the present invention in Embodiment 4.

[0035] Figure 5 This is a schematic diagram of the internal structure of the box of the present invention in Embodiment 5.

[0036] Figure 6 The diagrams show the internal structure of the housing according to Embodiments 6 and 7 of the present invention.

[0037] Figure 7 This is a block diagram of the control method of the present invention in an embodiment.

[0038] Legend: 1. Housing; 201. First insulation layer; 202. Second insulation layer; 301. First observation window; 302. Second observation window; 303. Third observation window; 4. Compressor; 501. First condenser; 502. Second condenser; 601. First evaporator; 602. Second evaporator; 603. Third evaporator; 701. First solenoid valve; 702. Second solenoid valve; 703. Third solenoid valve; 704. Fourth solenoid valve; 705. Fifth solenoid valve; 706. Sixth solenoid valve; 707. Seventh solenoid valve; 708. Eighth solenoid valve; 8. Separator; 901. First electronic expansion valve; 902. Second electronic expansion valve; 10. Diverter valve; 11. Heat exchanger; 1201. First pressure and temperature sensor; 1202. Second pressure and temperature sensor; 1203. Third pressure and temperature sensor; 13. Exhaust temperature sensor. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0040] Example 1:

[0041] like Figures 1-2 As shown, the environmental testing system of the present invention, which can be tested simultaneously, includes a chamber 1, a first insulation layer 201, a second insulation layer 202, a first observation window 301, a second observation window 302, and a third observation window 303. Each insulation layer is made of heat-insulating material and can move within the chamber. As needed, the first insulation layer 201 and the second insulation layer 202 can be used to divide the environmental chamber into three different test areas, and environmental tests under different conditions can be carried out simultaneously.

[0042] It also includes compressor 4, first condenser 501, second condenser 502, first evaporator 601, second evaporator 602, third evaporator 603, first solenoid valve 701, second solenoid valve 702, third solenoid valve 703, fourth solenoid valve 704, fifth solenoid valve 705, sixth solenoid valve 706, seventh solenoid valve 707, and eighth solenoid valve 708; the specific connection relationships of the above components are as follows:

[0043] like Figure 2As shown, the output terminal of compressor 4 is connected to one end of the first solenoid valve 701 and one end of the second solenoid valve 702. The other end of the first solenoid valve 701 is connected to one end of the first condenser 501. After the other end of the first condenser 501 is connected to the other end of the second solenoid valve 702, it is then connected to one end of the third solenoid valve 703 and one end of the fourth solenoid valve 704. The other end of the fourth solenoid valve 704 is connected to one end of the second condenser 502. After the other end of the second condenser 502 is connected to the other end of the third solenoid valve 703, it is then connected to one end of the fifth solenoid valve 705 and one end of the sixth solenoid valve 706. One end of the sixth solenoid valve 706 is connected to one end of the first evaporator 601 and one end of the second evaporator 602. After the other ends of the first evaporator 601 and the second evaporator 602 are connected, they are then connected to one end of the seventh solenoid valve 707 and one end of the eighth solenoid valve 708. The other end of the eighth solenoid valve 708 is connected to one end of the third evaporator 603. The other ends of the seventh solenoid valve 707 and the third evaporator 603 are both connected to the input end of the compressor 4. The other end of the second condenser 502 is connected to one end of the seventh solenoid valve 707 via the fifth solenoid valve 705.

[0044] The compressor 4 extracts low-temperature, low-pressure steam from different evaporators as needed and compresses it into high-temperature, high-pressure gaseous refrigerant. The first condenser 501 preheats the water and high-temperature environment zone required for the humidity test by releasing heat. The second condenser 502 releases the heat absorbed in the -25℃ or -40℃ low-temperature test zone to the outdoor air after preheating or when no high-temperature and humidity test is required. The low-temperature, low-pressure liquid refrigerant in the first evaporator 601 and the second evaporator 602 exchanges heat with the cooled objects in the -25℃ and -40℃ low-temperature test zones, respectively, and evaporates into gaseous refrigerant by absorbing heat. The third evaporator 603 absorbs heat from the air to preheat the water and high-temperature environment zone required for the humidity test when no low-temperature test is required.

[0045] The on / off state of the first solenoid valve 701 and the second solenoid valve 702 is determined by whether the first condenser 501 is activated. When no low-temperature test is required, the third evaporator 603 is activated by opening the fifth solenoid valve 705 and closing the sixth solenoid valve 706, while simultaneously closing the seventh solenoid valve 707 and opening the eighth solenoid valve 708. Conversely, when a low-temperature test is required, the corresponding solenoid valves are operated in the opposite manner.

[0046] In addition, it also includes a separator 8, a first electronic expansion valve 901, a second electronic expansion valve 902, a flow divider valve 10, and a heat exchanger 11. The separator 8 is used to separate the refrigerant. The refrigerant is a mixture of refrigerants with different boiling points to meet the refrigeration requirements of different temperature test zones. After the high-boiling-point refrigerant is diverted by the flow divider valve 10, part of it flows directly into the first electronic expansion valve 901, and the other part flows into the heat exchanger 11 to condense and absorb the heat released by the low-boiling-point gaseous refrigerant to achieve cooling. After being cooled by the heat exchanger 11, the low-boiling-point refrigerant flows into the second electronic expansion valve 902. The first electronic expansion valve 901 and the second electronic expansion valve 902 are throttling devices to control the flow rate of the low-pressure, low-temperature liquid refrigerant flowing into the evaporator.

[0047] It also includes a first evaporator pressure and temperature sensor 1201, a second evaporator pressure and temperature sensor 1202, a third evaporator pressure and temperature sensor 1203, and a compressor exhaust temperature sensor 13. The corresponding superheat obtained from the evaporator pressure and temperature sensor is used as the main feedback control signal, and the exhaust temperature is used as the auxiliary control signal to realize dual feedback fuzzy control of the corresponding electronic expansion valve.

[0048] This invention utilizes an insulation layer to divide the chamber 1 into several independent test zones. Through the design of the refrigeration and humidification system, environmental tests under different conditions can be carried out simultaneously in the same environmental chamber, fully realizing the mutual exchange of various heats, saving resources, and multiple tests can be carried out with one environmental chamber, greatly reducing costs and the occupation of test space.

[0049] To address the issue of high power load and slow response caused by heating water solely with electric heating elements in humidity tests, a condenser is used to preheat the water. This not only fully utilizes the heat generated during equipment operation, saving resources, but also accelerates the boiling point of the water, improving the response rate. Furthermore, the opening of the electronic expansion valve is controlled by two feedback parameters: superheat and exhaust temperature. The weight ratio of the two feedback signals is determined based on the rate of change of superheat. Simultaneously, fuzzy control is employed to achieve precise and rapid adjustment of the electronic expansion valve.

[0050] This invention also provides a control method for an environmental testing system based on the synchronous testing system described above, comprising:

[0051] The pressure and temperature signals of the first evaporator are obtained through the first pressure and temperature sensor; the pressure and temperature signals of the second evaporator are obtained through the second pressure and temperature sensor; the pressure and temperature signals of the third evaporator are obtained through the third pressure and temperature sensor; and the exhaust temperature of the compressor is obtained through the exhaust temperature sensor.

[0052] The controller controls the switching of each solenoid valve according to the type of test;

[0053] The controller uses the superheat of each evaporator obtained from each pressure and temperature sensor as the main feedback control signal and the exhaust temperature of the exhaust temperature sensor as the auxiliary control signal to achieve dual feedback fuzzy control of each electronic expansion valve.

[0054] Specifically, such as Figure 1-2 As shown, when three environmental zones are simultaneously subjected to environmental tests under three different conditions—alternating damp heat, a first low temperature (e.g., -25℃), and a second low temperature (e.g., -40℃)—the environmental chamber is divided into three different test zones using the first insulation layer 201 and the second insulation layer 202. The second solenoid valve 702, the fourth solenoid valve 704, the fifth solenoid valve 705, and the eighth solenoid valve 708 are closed, while the first solenoid valve 701, the third solenoid valve 703, the sixth solenoid valve 706, and the seventh solenoid valve 707 are simultaneously opened. This causes the compressor 4, the first condenser 501, the first evaporator 601, and the second evaporator 602 to work in coordination. The second condenser 502 and the third evaporator 603 are then closed. The compressor 4 draws away the steam generated in the first evaporator 601 and the second evaporator 602, compresses it into high-temperature, high-pressure steam, and discharges it. This steam releases heat in the first condenser 501, providing the water required for the alternating damp heat test. The mixed refrigerant, after being preheated in the high-temperature environment and cooled by exothermic cooling, flows into separator 8 for gas-liquid separation. The high-boiling-point refrigerant is divided into two paths by the diversion valve 10. One path flows directly into the first electronic expansion valve 901 after passing through separator 13. After throttling, it enters the first evaporator 601 to evaporate and absorb heat from the object being cooled, thus cooling the first low-temperature test zone. The gaseous refrigerant, after being vaporized by the low-boiling-point refrigerant in the separator, exchanges heat with the other path of high-boiling-point liquid refrigerant in heat exchanger 11. The high-boiling-point liquid refrigerant carries away the heat of the low-boiling-point refrigerant, causing it to re-liquefy and flow into the second electronic expansion valve 902. After throttling, it evaporates in the second evaporator 602 and absorbs heat from the object being cooled, thus cooling the second low-temperature test zone. The high-boiling-point refrigerant, after absorbing heat in heat exchanger 11, re-vaporizes and is finally drawn into compressor 4 along with the gaseous refrigerant flowing out of the first evaporator 601 and the second evaporator 602, starting the next cycle.

[0055] Example 2

[0056] like Figure 2As shown, when three environmental zones are simultaneously subjected to environmental tests under three different conditions—high temperature, low temperature -40℃, and low temperature -25℃—without humidity, the second solenoid valve 702, the fourth solenoid valve 704, the fifth solenoid valve 705, and the eighth solenoid valve 708 are closed, while the first solenoid valve 701, the third solenoid valve 703, the sixth solenoid valve 706, and the seventh solenoid valve 707 are simultaneously opened. This causes the compressor 4, the first condenser 501, the first evaporator 601, and the second evaporator 602 to work together, while the second condenser 502 and the third evaporator 603 are closed. The compressor 4 draws away the steam generated in the first evaporator 601 and the second evaporator 602 and compresses it into high-temperature, high-pressure steam before discharging it. The heat released in the first condenser 501 is only for preheating the high-temperature environmental zone. The rest of the working principle is the same as in Example 1.

[0057] Example 3

[0058] like Figure 3 As shown, when alternating damp heat and high temperature tests are not performed or preheating is completed, the first solenoid valve 701, the third solenoid valve 703, the fifth solenoid valve 705, and the eighth solenoid valve 708 are closed, while the second solenoid valve 702, the fourth solenoid valve 704, the sixth solenoid valve 706, and the seventh solenoid valve 707 are opened simultaneously, causing the compressor 4, the second condenser 502, the first evaporator 601, and the second evaporator 602 to work together. The first condenser 501 and the third evaporator 603 are closed, and the high-pressure gaseous refrigerant compressed by the compressor 4 no longer flows through the first condenser 501, but is cooled in the second condenser 502 to dissipate heat to the outside. The remaining working principle is the same as in Embodiment 1.

[0059] Example 4

[0060] like Figure 4 As shown, when only the low-temperature -25℃ test is performed, the first solenoid valve 701, the third solenoid valve 703, the fifth solenoid valve 705, and the eighth solenoid valve 708 are closed, while the second solenoid valve 702, the fourth solenoid valve 704, the sixth solenoid valve 706, and the seventh solenoid valve 707 are opened simultaneously. The compressor 4, the second condenser 502, and the first evaporator 601 work together to stop the first condenser 501, the second evaporator 602, and the third evaporator 603 from working. In addition, the function of the separator 8 is turned off and the flow divider valve 10 is adjusted so that the mixed refrigerant flows through the separator 8 and the flow divider valve 10 simultaneously and is throttled by the first electronic expansion valve 901. It evaporates and absorbs heat in the first evaporator 601, and after being compressed by the compressor 4, it releases the heat in the second condenser 502 and then enters the next refrigeration cycle.

[0061] Example 5

[0062] like Figure 5As shown, when only the low-temperature -40℃ test is performed, the first solenoid valve 701, the third solenoid valve 703, the fifth solenoid valve 705, and the eighth solenoid valve 708 are closed, while the second solenoid valve 702, the fourth solenoid valve 704, the sixth solenoid valve 706, and the seventh solenoid valve 707 are opened simultaneously. The compressor 4, the second condenser 502, and the second evaporator 602 work together to stop the first condenser 501, the first evaporator 601, and the third evaporator 603 from working. At the same time, the flow divider valve 10 is adjusted so that all the high-boiling-point refrigerant flows into the heat exchanger 11 to absorb heat and cool the low-boiling-point refrigerant. After being throttled by the second electronic expansion valve 902, it evaporates and absorbs heat in the second evaporator 602. After being compressed by the compressor 4, the heat is released in the second condenser 502, and then the next refrigeration cycle begins.

[0063] Example 6

[0064] like Figure 6 As shown, when only alternating damp heat test is performed, the second solenoid valve 702, the fourth solenoid valve 704, the sixth solenoid valve 706 and the seventh solenoid valve 707 are closed, while the second solenoid valve 701, the third solenoid valve 703, the fifth solenoid valve 705 and the eighth solenoid valve 708 are opened simultaneously. The compressor 4, the first condenser 501 and the third evaporator 603 work simultaneously. The refrigerant absorbs heat from the outdoor air in the third evaporator 603 and is then compressed into high-temperature and high-pressure steam by the compressor 4. The steam releases heat in the first condenser 501 to preheat the water required for alternating damp heat and the high-temperature environment zone.

[0065] Example 7

[0066] like Figure 6 As shown, when only high-temperature testing is performed, the second solenoid valve 702, the fourth solenoid valve 704, the sixth solenoid valve 706, and the seventh solenoid valve 707 are closed, while the second solenoid valve 701, the third solenoid valve 703, the fifth solenoid valve 705, and the eighth solenoid valve 708 are opened simultaneously. The compressor 4, the first condenser 501, and the third evaporator 603 work simultaneously. The refrigerant absorbs heat from the outdoor air in the third evaporator 603 and is then compressed into high-temperature and high-pressure steam by the compressor 4. The heat is released in the first condenser 501, which is only for preheating the high-temperature environment.

[0067] Example 8

[0068] like Figure 7As shown, e1 and e2 represent the differences between the actual and set values ​​of superheat and exhaust temperature, respectively, i.e., the magnitude of the actual superheat error. 'a' is the proportional coefficient, and h' and h'' are the superheat feedback output and exhaust temperature feedback output, respectively. The final output of the electronic expansion valve is h = h' + h''. The opening of the electronic expansion valve is controlled by the two feedback parameters of superheat and exhaust temperature. When the rate of change of superheat is large, the proportional coefficient 'a' of the superheat feedback signal's influence weight is increased, and the proportional coefficient '1-a' of the exhaust temperature feedback signal's influence weight decreases. In this case, the superheat signal is used as the primary feedback signal, enabling rapid adjustment of the electronic expansion valve. Conversely, when the rate of change of superheat is slow, the proportional coefficient 'a' of the superheat feedback signal's influence weight is decreased, and the proportional coefficient '1-a' of the exhaust temperature feedback signal's influence weight increases significantly. In this case, the exhaust temperature signal is used as the primary feedback signal, also enabling rapid adjustment of the electronic expansion valve. Furthermore, this invention utilizes the robustness of fuzzy control, determining the output signal magnitude based on the error and the rate of change of error, greatly improving control accuracy and facilitating precise control of the ambient chamber temperature.

[0069] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. An environmental testing system capable of simultaneous testing, characterized in that, It includes a housing (1), a compressor (4), a first condenser (501), a second condenser (502), a first evaporator (601), a second evaporator (602), and a third evaporator (603). The housing (1) is provided with a heat insulation layer to divide the housing (1) into multiple test areas for different types of tests. One end of the first evaporator (601) and the second evaporator (602) connected in parallel is connected to one end of the third evaporator (603), and the other end is connected to the output end of the compressor (4) via the second condenser (502) and the first condenser (501) in sequence. The other end of the third evaporator (603) is connected to the input end of the compressor (4). The compressor (4) is used to extract low-temperature, low-pressure steam from different evaporators and compress it into high-temperature, high-pressure gaseous refrigerant; The first condenser (501) is used to preheat the water required for the humidity test area and the high-temperature environment area by releasing heat; The second condenser (502) is used to release the heat absorbed in each low temperature test zone into the outdoor air after preheating or when high temperature and humidity tests are not required. The low-temperature, low-pressure liquid refrigerant in the first evaporator (601) and the second evaporator (602) exchange heat with the objects being cooled in different low-temperature test zones, and evaporate into gaseous refrigerant by absorbing heat. The third evaporator (603) is used to absorb heat from the air to preheat the water required for the humidity test area and the high-temperature environment area when low-temperature testing is not required.

2. The environmental testing system capable of synchronous testing according to claim 1, characterized in that, It also includes a first solenoid valve (701), a second solenoid valve (702), a third solenoid valve (703), a fourth solenoid valve (704), a fifth solenoid valve (705), a sixth solenoid valve (706), a seventh solenoid valve (707), and an eighth solenoid valve (708); the output end of the compressor (4) is connected to one end of the first solenoid valve (701) and one end of the second solenoid valve (702), respectively. The other end of the first solenoid valve (701) is connected to one end of the first condenser (501). The other end of the first condenser (501) is connected to the other end of the second solenoid valve (702), and then to one end of the third solenoid valve (703) and one end of the fourth solenoid valve (704), respectively. The other end of the fourth solenoid valve (704) is connected to one end of the second condenser (502), and the other end of the second condenser (502) is connected to the third solenoid valve (708). After the other end of the solenoid valve (703) is connected, it is then connected to one end of the fifth solenoid valve (705) and one end of the sixth solenoid valve (706). The other end of the sixth solenoid valve (706) is connected to one end of the first evaporator (601) and one end of the second evaporator (602). After the other end of the first evaporator (601) and the other end of the second evaporator (602) are connected, they are then connected to one end of the seventh solenoid valve (707) and one end of the eighth solenoid valve (708). The other end of the eighth solenoid valve (708) is connected to one end of the third evaporator (603). The other end of the seventh solenoid valve (707) and the other end of the third evaporator (603) are both connected to the input end of the compressor (4). The other end of the second condenser (502) is connected to one end of the seventh solenoid valve (707) via the fifth solenoid valve (705).

3. The environmental testing system capable of synchronous testing according to claim 2, characterized in that, It also includes a separator (8), a first electronic expansion valve (901), a second electronic expansion valve (902), a diversion valve (10), and a heat exchanger (11); one end of the first evaporator (601) is connected to the separator (8) in sequence via the first electronic expansion valve (901) and the diversion valve (10), and the separator (8) is connected to one end of the second evaporator (602) in sequence via the heat exchanger (11) and the second electronic expansion valve (902); wherein the separator (8) is used to separate the refrigerant, wherein the refrigerant uses different boiling points. The mixed refrigerant is used to meet the refrigeration requirements of different temperature test zones. After the high-boiling-point refrigerant is diverted by the diversion valve (10), part of it flows directly into the first electronic expansion valve (901), and the other part flows into the heat exchanger (11) to condense and absorb the heat released by the low-boiling-point gaseous refrigerant to achieve cooling. After the low-boiling-point refrigerant is cooled by the heat exchanger (11), it flows into the second electronic expansion valve (902). The first electronic expansion valve (901) and the second electronic expansion valve (902) control the flow rate of the low-pressure low-temperature liquid refrigerant flowing into the evaporator by throttling.

4. The environmental testing system capable of simultaneous testing according to claim 3, characterized in that, It also includes a first pressure and temperature sensor (1201), a second pressure and temperature sensor (1202), a third pressure and temperature sensor (1203), an exhaust temperature sensor (13), and a controller. The first pressure and temperature sensor (1201) is located at the other end of the first evaporator (601), the second pressure and temperature sensor (1202) is located at the other end of the second evaporator (602), the third pressure and temperature sensor (1203) is located at the other end of the third evaporator (603), and the exhaust temperature sensor (13) is located at the output end of the compressor (4). The controller uses the superheat of each evaporator obtained from each pressure and temperature sensor as the main feedback control signal and the exhaust temperature of the exhaust temperature sensor (13) as the auxiliary control signal to realize dual feedback fuzzy control of each electronic expansion valve.

5. A control method for an environmental testing system capable of synchronous testing as described in claim 4, characterized in that, include: The pressure and temperature signals of the first evaporator (601) are obtained through the first pressure and temperature sensor (1201); the pressure and temperature signals of the second evaporator (602) are obtained through the second pressure and temperature sensor (1202); the pressure and temperature signals of the third evaporator (603) are obtained through the third pressure and temperature sensor (1203); and the exhaust temperature of the compressor (4) is obtained through the exhaust temperature sensor (13). The controller controls the switching of each solenoid valve according to the test type; The controller uses the superheat of each evaporator obtained from each pressure and temperature sensor as the main feedback control signal and the exhaust temperature of the exhaust temperature sensor (13) as the auxiliary control signal to realize dual feedback fuzzy control of each electronic expansion valve.

6. The control method according to claim 5, characterized in that, When conducting environmental tests under alternating damp heat, first low temperature conditions, and second low temperature conditions simultaneously, the chamber (1) is divided into three different test zones using a heat insulation layer. The second solenoid valve (702), fourth solenoid valve (704), fifth solenoid valve (705), and eighth solenoid valve (708) are closed, while the first solenoid valve (701), third solenoid valve (703), sixth solenoid valve (706), and seventh solenoid valve (707) are opened simultaneously, causing the compressor (4), first condenser (501), first evaporator (601), and second evaporator (602) to work together. The second condenser (502) and third evaporator (603) are closed. The compressor (4) draws away the steam generated in the first evaporator (601) and second evaporator (602) and compresses it into high-temperature and high-pressure steam before discharging it. This steam is then released in the first condenser (501) to preheat the water required for the alternating damp heat test and the high-temperature environment zone. After being cooled, the mixed refrigerant flows into the separator (8) for gas-liquid separation. The high-boiling-point refrigerant is divided into two paths by the diversion valve (10). One path flows directly into the first electronic expansion valve (901) after passing through the separator (8). After throttling, it enters the first evaporator (601) to evaporate and absorb the heat of the object being cooled, thus cooling the low-temperature test zone. The low-boiling-point refrigerant that has passed through the separator (8) is vaporized and then exchanged heat with the other high-boiling-point liquid refrigerant in the heat exchanger (11). The high-boiling-point liquid refrigerant carries away the heat of the low-boiling-point refrigerant, causing it to re-liquefy and flow into the second electronic expansion valve (902). After throttling, it evaporates in the second evaporator (602) and absorbs the heat of the object being cooled, thus cooling the low-temperature test zone. The high-boiling-point refrigerant that has passed through the heat exchanger (11) absorbs heat and then re-vaporizes. Finally, it is drawn into the compressor (4) together with the gaseous refrigerant flowing out of the first evaporator (601) and the second evaporator (602) to start the next cycle.

7. The control method according to claim 6, characterized in that, When environmental tests are conducted simultaneously under high temperature, first low temperature, and second low temperature conditions without humidity, the second solenoid valve (702), the fourth solenoid valve (704), the fifth solenoid valve (705), and the eighth solenoid valve (708) are closed, while the first solenoid valve (701), the third solenoid valve (703), the sixth solenoid valve (706), and the seventh solenoid valve (707) are opened simultaneously, causing the compressor (4), the first condenser (501), the first evaporator (601), and the second evaporator (602) to work together. The second condenser (502) and the third evaporator (603) are closed. The compressor (4) draws away the steam generated in the first evaporator (601) and the second evaporator (602) and compresses it into high temperature and high pressure steam before discharging it. This allows the first condenser (501) to release heat only for preheating the high temperature environment.

8. The control method according to claim 6, characterized in that, When alternating damp heat and high temperature tests are not performed or preheating is completed, the first solenoid valve (701), the third solenoid valve (703), the fifth solenoid valve (705), and the eighth solenoid valve (708) are closed, and the second solenoid valve (702), the fourth solenoid valve (704), the sixth solenoid valve (706), and the seventh solenoid valve (707) are opened simultaneously, causing the compressor (4), the second condenser (502), the first evaporator (601), and the second evaporator (602) to work together. The first condenser (501) and the third evaporator (603) are closed, and the high-pressure gaseous refrigerant compressed by the compressor (4) no longer flows through the first condenser (501), but is cooled in the second condenser (502) to dissipate heat to the outside.

9. The control method according to claim 6, characterized in that, When only the first low-temperature test is performed, the first solenoid valve (701), the third solenoid valve (703), the fifth solenoid valve (705), and the eighth solenoid valve (708) are closed, while the second solenoid valve (702), the fourth solenoid valve (704), the sixth solenoid valve (706), and the seventh solenoid valve (707) are opened simultaneously. The compressor (4), the second condenser (502), and the first evaporator (601) work together to stop the first condenser (501), the second evaporator (602), and the third evaporator (603) from working. In addition, the function of the separator (8) is turned off and the flow divider valve (10) is adjusted so that the mixed refrigerant flows through the separator (8) and the flow divider valve (10) and is throttled by the first electronic expansion valve (901). It evaporates and absorbs heat in the first evaporator (601), and after being compressed by the compressor (4), it releases heat in the second condenser (502) and then enters the next refrigeration cycle.

10. The control method according to claim 6, characterized in that, When only the second low-temperature test is performed, the first solenoid valve (701), the third solenoid valve (703), the fifth solenoid valve (705), and the eighth solenoid valve (708) are closed, while the second solenoid valve (702), the fourth solenoid valve (704), the sixth solenoid valve (706), and the seventh solenoid valve (707) are opened simultaneously. The compressor (4), the second condenser (502), and the second evaporator (602) work together to stop the first condenser (501), the first evaporator (601), and the third evaporator (603) from working. At the same time, the flow divider valve (10) is adjusted so that all the high-boiling-point refrigerant flows into the heat exchanger (11) to absorb heat and cool the low-boiling-point refrigerant. After being throttled by the second electronic expansion valve (902), the refrigerant evaporates and absorbs heat in the second evaporator (602). After being compressed by the compressor (4), the heat is released in the second condenser (502), and then the next refrigeration cycle begins.

11. The control method according to claim 6, characterized in that, When only alternating damp heat test is performed, the second solenoid valve (702), the fourth solenoid valve (704), the sixth solenoid valve (706) and the seventh solenoid valve (707) are closed, and the second solenoid valve (702), the third solenoid valve (703), the fifth solenoid valve (705) and the eighth solenoid valve (708) are opened at the same time. The compressor (4), the first condenser (501) and the third evaporator (603) work at the same time. The refrigerant absorbs heat from the outdoor air in the third evaporator (603) and is then compressed into high temperature and high pressure steam by the compressor (4). The refrigerant releases heat in the first condenser (501) to preheat the water and high temperature environment required for alternating damp heat test.

12. The control method according to claim 6, characterized in that, When only high-temperature testing is performed, the second solenoid valve (702), the fourth solenoid valve (704), the sixth solenoid valve (706), and the seventh solenoid valve (707) are closed, while the second solenoid valve (702), the third solenoid valve (703), the fifth solenoid valve (705), and the eighth solenoid valve (708) are opened simultaneously. The compressor (4), the first condenser (501), and the third evaporator (603) work simultaneously. The refrigerant absorbs heat from the outdoor air in the third evaporator (603) and is then compressed into high-temperature and high-pressure steam by the compressor (4). The heat is released in the first condenser (501) only for preheating the high-temperature environment.

13. The control method according to claim 6, characterized in that, When the rate of superheat change is large, the proportional coefficient 'a' of the superheat feedback signal's influence weight is increased, and the proportional coefficient '1-a' of the corresponding exhaust temperature feedback signal's influence weight decreases. In this case, the superheat signal is used as the main feedback signal to regulate the electronic expansion valve. Conversely, when the rate of superheat change is slow, the proportional coefficient 'a' of the superheat feedback signal's influence weight is decreased, and the proportional coefficient '1-a' of the corresponding exhaust temperature feedback signal's influence weight will increase significantly. In this case, the exhaust temperature signal is used as the main feedback signal to achieve rapid regulation of the electronic expansion valve.

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