Condensation pressure control method and device of environmental test box and environmental test box

Abstract

The embodiment of the invention discloses a condensation pressure control method and device of an environmental test box and the environmental test box. The environment test box comprises a box body, a control system, a refrigerating system and a water path system, the refrigerating system is located in the box body, the control system comprises a controller and a temperature sensor, the refrigerating system comprises a compressor, a condenser, an evaporator and a throttling element, and the water path system comprises an electric ball valve, a water outlet pipeline and a water inlet pipeline; the condensation pressure control method is executed by a controller and comprises the steps that the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature of a condenser are obtained; according to the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature, the water side temperature difference and the refrigerant temperature difference of the condenser are determined; and controlling the opening degree of the electric ball valve according to the water side temperature difference and the refrigerant temperature difference so as to control the condensing pressure of the environmental test box. According to the technical scheme of the environment test box provided by the embodiment of the invention, the control reliability can be ensured.

Description

Technical Field

[0001] The embodiments of the present invention relate to a test chamber control technology, and more particularly to a condensation pressure control method and device of an environmental test chamber, and an environmental test chamber. Background Art

[0002] Environmental test chambers can be used for temperature and humidity testing. For products or equipment that require temperature and humidity testing, they are usually tested in environmental test chambers. To meet the testing requirements of products or equipment, the temperature and humidity in the environmental test chamber must be controllable, and the condensation pressure must also be controllable to ensure actual application requirements.

[0003] At present, the existing condensing pressure control method of the environmental test chamber is usually to directly control the condensing pressure by adjusting the pressure regulating valve. However, the pressure regulating valve has the problems of hysteresis and small adjustment range, which affects the control reliability. Summary of the invention

[0004] The embodiments of the present invention provide a condensation pressure control method and device of an environmental test box and an environmental test box to ensure control reliability.

[0005] In a first aspect, an embodiment of the present invention provides a condensing pressure control method for an environmental test box, wherein the environmental test box includes a box body, a control system, a refrigeration system and a water system, wherein the refrigeration system is located inside the box body, the control system includes a controller and a temperature sensor, the refrigeration system includes a compressor, a condenser, an evaporator and a throttling element, and the water system includes an electric ball valve, a water outlet pipeline and a water inlet pipeline; the outlet of the compressor is communicated with the liquid inlet of the condenser, the liquid outlet of the condenser is communicated with the inlet of the evaporator, the outlet of the evaporator is communicated with the inlet of the compressor, the throttling element is arranged in the pipeline connecting the condenser and the evaporator, the temperature sensor is arranged on one side of the water outlet pipeline and the water inlet pipeline close to the condenser, the electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is communicated with the water outlet pipeline, the water inlet of the condenser is communicated with the water inlet pipeline, and the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected; the condensing pressure control method is executed by the controller, and the condensing pressure control method includes:

[0006] Obtaining the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser;

[0007] Determine the water side temperature difference and the refrigerant temperature difference of the condenser according to the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature;

[0008] The opening of the electric ball valve is controlled according to the water-side temperature difference and the refrigerant temperature difference to control the condensing pressure of the environmental test box.

[0009] Optionally, determining the water-side temperature difference and the refrigerant temperature difference of the condenser according to the real-time water inlet temperature, the real-time water outlet temperature, and the real-time liquid outlet temperature includes:

[0010] The difference between the real-time water outlet temperature and the real-time water inlet temperature is used as the water side temperature difference;

[0011] The difference between the target liquid outlet temperature and the real-time liquid outlet temperature is used as the refrigerant temperature difference.

[0012] Optionally, controlling the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference includes:

[0013] When the refrigerant temperature difference remains unchanged and the water-side temperature difference increases, controlling the opening of the electric ball valve to increase or remain unchanged;

[0014] When the water-side temperature difference remains unchanged and the refrigerant temperature difference increases, the opening of the electric ball valve is controlled to decrease.

[0015] Optionally, controlling the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference includes:

[0016] When the refrigerant temperature difference is less than zero, controlling the opening of the electric ball valve to increase;

[0017] When the refrigerant temperature difference is greater than zero, the opening of the electric ball valve is controlled to decrease.

[0018] Optionally, controlling the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference includes:

[0019] When the refrigerant temperature difference is less than zero and the water-side temperature difference remains unchanged, the opening of the electric ball valve is controlled to increase, and the opening required to be increased by the electric ball valve decreases as the refrigerant temperature difference increases;

[0020] When the refrigerant temperature difference is greater than zero and the water-side temperature difference remains unchanged, the opening of the electric ball valve is controlled to decrease, and the opening required to be reduced by the electric ball valve increases as the refrigerant temperature difference increases;

[0021] When the refrigerant temperature difference is less than zero and the refrigerant temperature difference remains unchanged, the opening of the electric ball valve is controlled to increase, and the opening required to be increased by the electric ball valve increases with the increase of the water-side temperature difference;

[0022] When the refrigerant temperature difference is greater than zero and remains unchanged, the opening of the electric ball valve is controlled to decrease, and the opening required to be reduced by the electric ball valve decreases as the water-side temperature difference increases.

[0023] Optionally, controlling the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference includes:

[0024] When the water side temperature is lower than a preset low temperature threshold, the opening of the electric ball valve is controlled to be a preset large opening;

[0025] When the water side temperature is higher than a preset high temperature threshold, the opening of the electric ball valve is controlled to be a preset small opening.

[0026] Optionally, after obtaining the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser, the method further includes:

[0027] The initial opening of the electric ball valve is determined according to the real-time water inlet temperature.

[0028] In a second aspect, an embodiment of the present invention provides a condensing pressure control device for an environmental test box, the environmental test box comprising a box body, a control system, a refrigeration system and a water system, the refrigeration system being located inside the box body, the control system comprising a controller and a temperature sensor, the refrigeration system comprising a compressor, a condenser, an evaporator and a throttling element, the water system comprising an electric ball valve, a water outlet pipeline and a water inlet pipeline; the outlet of the compressor is communicated with the liquid inlet of the condenser, the liquid outlet of the condenser is communicated with the inlet of the evaporator, the outlet of the evaporator is communicated with the inlet of the compressor, the throttling element is arranged in the pipeline connecting the condenser and the evaporator, the temperature sensor is arranged on the side of the water outlet pipeline and the water inlet pipeline close to the condenser, the electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is communicated with the water outlet pipeline, the water inlet of the condenser is communicated with the water inlet pipeline, the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected;

[0029] The condensing pressure control device comprises:

[0030] A temperature acquisition module, used to acquire the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser;

[0031] a temperature difference determination module, for determining a water side temperature difference and a refrigerant temperature difference of the condenser according to the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature;

[0032] The opening control module is used to control the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference, so as to control the condensing pressure of the environmental test box.

[0033] In the third aspect, an embodiment of the present invention provides an environmental test chamber, comprising: a chamber, a control system, a refrigeration system and a water system, wherein the refrigeration system is located inside the chamber, the control system comprises a controller and a temperature sensor, the refrigeration system comprises a compressor, a condenser, an evaporator and a throttling element, and the water system comprises an electric ball valve, a water outlet pipe and a water inlet pipe; the outlet of the compressor is connected to the liquid inlet of the condenser, the liquid outlet of the condenser is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the compressor, the throttling element is arranged in the pipe connecting the condenser and the evaporator, the temperature sensor is arranged on the side of the water outlet pipe and the water inlet pipe close to the condenser, the electric ball valve is located in the water outlet pipe, the water outlet of the condenser is connected to the water outlet pipe, the water inlet of the condenser is connected to the water inlet pipe, the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected; the condensing pressure control device as described in the second aspect is integrated in the controller.

[0034] Optionally, water pressure gauges are provided in both the water inlet pipeline and the water outlet pipeline, and a water pressure protector is also provided in the water inlet pipeline.

[0035] The embodiment of the present invention provides a condensing pressure control method and device for an environmental test box, and the environmental test box. The environmental test box includes a box body, a control system, a refrigeration system and a water system. The refrigeration system is located inside the box body. The control system includes a controller and a temperature sensor. The refrigeration system includes a compressor, a condenser, an evaporator and a throttling element. The water system includes an electric ball valve, a water outlet pipeline and a water inlet pipeline. The outlet of the compressor is connected to the liquid inlet of the condenser, the liquid outlet of the condenser is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the compressor, and a throttling element is provided in the pipeline connecting the condenser and the evaporator. The water outlet pipeline and the water inlet pipeline are close to each other. A temperature sensor is provided on one side near the condenser, an electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is connected to the water outlet pipeline, the water inlet of the condenser is connected to the water inlet pipeline, the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected; the condensing pressure control method is executed by the controller, and the condensing pressure control method includes: obtaining the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature of the condenser; determining the water side temperature difference and the refrigerant temperature difference of the condenser according to the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature; controlling the opening of the electric ball valve according to the water side temperature difference and the refrigerant temperature difference to control the condensing pressure of the environmental test box. The condensing pressure control method, device and environmental test box of the environmental test box provided by the embodiment of the present invention control the opening of the electric ball valve to increase or decrease in real time according to the determined water side temperature difference and refrigerant temperature difference, thereby controlling the condensing pressure of the environmental test box, solving the problems of hysteresis and small adjustment range of the pressure regulating valve in the prior art, thereby ensuring control reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of a condensation pressure control method of an environmental test chamber provided in Embodiment 1 of the present invention;

[0037] Figure 2 This is a flow chart of a condensation pressure control method of an environmental test chamber provided in Embodiment 2 of the present invention;

[0038] Figure 3 It is a structural block diagram of a condensing pressure control device of an environmental test box provided in Embodiment 3 of the present invention;

[0039] Figure 4 It is a schematic diagram of a partial structure of an environmental test box provided in Embodiment 4 of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0041] Embodiment 1

[0042] Figure 1 It is a flow chart of a condensing pressure control method of an environmental test box provided in Example 1 of the present invention. This embodiment can be applied to aspects such as condensing pressure control of an environmental test box. The environmental test box includes a box body, a control system, a refrigeration system and a water system. The refrigeration system is located inside the box body. The control system includes a controller and a temperature sensor. The refrigeration system includes a compressor, a condenser, an evaporator and a throttling element. The water system includes an electric ball valve, a water outlet pipeline and a water inlet pipeline. The outlet of the compressor is connected to the liquid inlet of the condenser, the liquid outlet of the condenser is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the compressor, a throttling element is provided in the pipeline connecting the condenser and the evaporator, a temperature sensor is provided on the side of the water outlet pipeline and the water inlet pipeline close to the condenser, the electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is connected to the water outlet pipeline, the water inlet of the condenser is connected to the water inlet pipeline, the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected. The condensing pressure control method is executed by a controller, and the controller can be implemented in the form of software and / or hardware. The condensing pressure method specifically includes the following steps:

[0043] Step 110: Obtain the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser.

[0044] Among them, the water inlet, water outlet and liquid outlet of the condenser are all provided with temperature sensors, and the controller is electrically connected to each temperature sensor to obtain the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser.

[0045] In addition, when the refrigeration system is turned on, the initial opening of the electric ball valve is determined according to the real-time inlet water temperature of the condenser. For example, when the refrigeration system is turned on, if the real-time inlet water temperature of the condenser is greater than 18 degrees Celsius, the initial opening of the electric ball valve is 60%, if the real-time inlet water temperature of the condenser is between 12 and 18 degrees Celsius, the initial opening of the electric ball valve is 40%, and if the real-time inlet water temperature of the condenser is less than 12 degrees Celsius, the initial opening of the electric ball valve is 25%.

[0046] It should be noted that the initial opening of the above-mentioned electric ball valve at different water inlet temperatures is only for schematic illustration and is determined according to the actual performance parameters of the refrigeration system and the water system and is not limited here.

[0047] Step 120: Determine the water side temperature difference and the refrigerant temperature difference of the condenser according to the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature.

[0048] The water side temperature difference of the condenser is the difference between the outlet water temperature and the inlet water temperature of the condenser, such as the current water side temperature difference of the condenser is the difference between the current outlet water temperature and the current inlet water temperature of the condenser. The refrigerant temperature difference of the condenser is the difference between the target outlet liquid temperature of the condenser and the actual outlet liquid temperature, such as the current refrigerant temperature difference of the condenser is the difference between the target outlet liquid temperature of the condenser and the current outlet liquid temperature. Exemplarily, the target outlet liquid temperature is 30 degrees Celsius.

[0049] Step 130: Control the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference to control the condensing pressure of the environmental test chamber.

[0050] Specifically, when the refrigerant temperature difference is less than zero and the water side temperature difference remains unchanged (can be within a certain range), the opening of the electric ball valve is controlled to increase, and the opening required to be increased by the electric ball valve decreases as the refrigerant temperature difference increases; when the refrigerant temperature difference is greater than zero and the water side temperature difference remains unchanged, the opening of the electric ball valve is controlled to decrease, and the opening required to be reduced by the electric ball valve increases as the refrigerant temperature difference increases; when the refrigerant temperature difference is less than zero and the refrigerant temperature difference remains unchanged, the opening of the electric ball valve is controlled to increase, and the opening required to be increased by the electric ball valve increases as the water side temperature difference increases; when the refrigerant temperature difference is greater than zero and the refrigerant temperature difference remains unchanged, the opening of the electric ball valve is controlled to decrease, and the opening required to be reduced by the electric ball valve decreases as the water side temperature difference increases. For example, when the water side temperature difference is between 2-3 degrees Celsius, if the refrigerant temperature difference is between -3 and -2 degrees Celsius, the electric ball valve is controlled to increase its opening by 4%, if the refrigerant temperature difference is between -2 and -1 degrees Celsius, the electric ball valve is controlled to increase its opening by 2%, if the refrigerant temperature difference is between 1 and 2 degrees Celsius, the electric ball valve is controlled to decrease its opening by 6%, and if the refrigerant temperature difference is greater than 2 degrees Celsius, the electric ball valve is controlled to decrease its opening by 8%. When the refrigerant temperature difference is between -2 and -1 degrees Celsius, if the water side temperature difference is between 2-3 degrees Celsius, the electric ball valve is controlled to increase its opening by 2%, and if the water side temperature difference is between 3-5 degrees Celsius, the electric ball valve is controlled to increase its opening by 4%. When the refrigerant temperature difference is between 1 and 2 degrees Celsius, if the water side temperature difference is between 2-3 degrees Celsius, the opening of the electric ball valve is controlled to be reduced by 6%. If the water side temperature difference is between 3-5 degrees Celsius, the opening of the electric ball valve is controlled to be reduced by 4%.

[0051] It should be noted that the numerical value of the increase or decrease in the opening degree of the above-mentioned electric ball valve as the refrigerant temperature difference and the water side temperature change is only a schematic illustration, which is determined according to the actual working requirements of the refrigeration system and the water system and is not limited here.

[0052] The condensing pressure control method of the environmental test chamber provided in the present embodiment includes: obtaining the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser; determining the water side temperature difference and the refrigerant temperature difference of the condenser according to the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature; controlling the opening of the electric ball valve according to the water side temperature difference and the refrigerant temperature difference to control the condensing pressure of the environmental test chamber. The condensing pressure control method of the environmental test chamber provided in the present embodiment controls the opening of the electric ball valve to increase or decrease in real time according to the determined water side temperature difference and refrigerant temperature difference, thereby controlling the condensing pressure of the environmental test chamber, solving the problems of hysteresis and small adjustment range of the pressure regulating valve in the prior art, thereby ensuring control reliability.

[0053] Embodiment 2

[0054] Figure 2 It is a flow chart of a condensing pressure control method of an environmental test box provided in the second embodiment of the present invention. This embodiment can be applied to aspects such as condensing pressure control of an environmental test box. The environmental test box includes a box body, a control system, a refrigeration system and a water system. The refrigeration system is located inside the box body. The control system includes a controller and a temperature sensor. The refrigeration system includes a compressor, a condenser, an evaporator and a throttling element. The water system includes an electric ball valve, a water outlet pipeline and a water inlet pipeline. The outlet of the compressor is connected to the liquid inlet of the condenser, the liquid outlet of the condenser is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the compressor, a throttling element is provided in the pipeline connecting the condenser and the evaporator, a temperature sensor is provided on the side of the water outlet pipeline and the water inlet pipeline close to the condenser, the electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is connected to the water outlet pipeline, the water inlet of the condenser is connected to the water inlet pipeline, the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected. The condensing pressure control method is executed by a controller, and the controller can be implemented in the form of software and / or hardware. The condensing pressure method specifically includes the following steps:

[0055] Step 210: Obtain the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser.

[0056] Among them, the water inlet, water outlet and liquid outlet of the condenser are all provided with temperature sensors, and the controller is electrically connected to each temperature sensor to obtain the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser.

[0057] In addition, when the refrigeration system is turned on and operating, the initial opening degree of the electric ball valve is determined according to the real-time inlet water temperature of the condenser. Exemplarily, when the refrigeration system is turned on and operating, if the real-time inlet water temperature of the condenser is greater than 18 degrees Celsius, the initial opening degree of the electric ball valve is 60%; if the real-time inlet water temperature of the condenser is between 12 and 18 degrees Celsius, the initial opening degree of the electric ball valve is 40%; if the real-time inlet water temperature of the condenser is less than 12 degrees Celsius, the initial opening degree of the electric ball valve is 25%.

[0058] It should be noted that the initial opening degrees of the above-mentioned electric ball valve at different inlet water temperatures are only for illustrative purposes, and are specifically determined according to the actual performance parameters of the refrigeration system and the water circuit system, and are not limited herein.

[0059] Step 220: Take the difference between the real-time outlet water temperature and the real-time inlet water temperature as the water-side temperature difference, and take the difference between the target liquid outlet temperature and the real-time liquid outlet temperature as the refrigerant temperature difference.

[0060] Exemplarily, the target liquid outlet temperature is 30 degrees Celsius.

[0061] Step 230: When the refrigerant temperature difference remains unchanged and the water-side temperature difference increases, control the opening degree of the electric ball valve to increase or remain unchanged; when the water-side temperature difference remains unchanged and the refrigerant temperature difference increases, control the opening degree of the electric ball valve to decrease.

[0062] Specifically, the variation of the opening degree of the electric ball valve with the refrigerant temperature difference T1 and the water-side temperature difference T2 is shown in Table 1. Among them, the corresponding specific adjustment opening degrees of the electric ball valve for the ranges of the refrigerant temperature difference and the water-side temperature difference (the temperature difference unit is degrees Celsius) are as follows: when T1 ≤ -3 and T2 < 2, the opening degree of the electric ball valve +4%, that is, the opening degree increases by 4%; when -1 < T1 ≤ 0 and T2 < 2, the opening degree of the electric ball valve -1%, that is, the opening degree decreases by 4%. The preset time after each adjustment of the opening degree of the electric ball valve is readjusted, such as 30s. Exemplarily, -0.5 < T1 < 0.5 is the stable state.

[0063] Table 1

[0064]

[0065] Step 240: When the refrigerant temperature difference is less than zero, control the opening degree of the electric ball valve to increase; when the refrigerant temperature difference is greater than zero, control the opening degree of the electric ball valve to decrease.

[0066] Specifically, when the refrigerant temperature difference is less than zero, the opening degree of the electric ball valve needs to increase, and the degree of increase of the opening degree of the electric ball valve is different for different ranges of the water-side temperature difference. When the refrigerant temperature difference is greater than zero, the opening degree of the electric ball valve needs to decrease, and the degree of decrease of the opening degree of the electric ball valve is different for different ranges of the water-side temperature difference.

[0067] Step 250: When the refrigerant temperature difference is less than zero and the water-side temperature difference remains unchanged, the opening of the electric ball valve is controlled to increase, and the opening required to be increased by the electric ball valve decreases as the refrigerant temperature difference increases.

[0068] Step 260: When the refrigerant temperature difference is greater than zero and the water-side temperature difference remains unchanged, the opening of the electric ball valve is controlled to decrease, and the opening required to be reduced by the electric ball valve increases as the refrigerant temperature difference increases.

[0069] Step 270: When the refrigerant temperature difference is less than zero and the refrigerant temperature difference remains unchanged, the opening of the electric ball valve is controlled to increase, and the opening required to be increased by the electric ball valve increases with the increase of the water-side temperature difference.

[0070] Step 280: When the refrigerant temperature difference is greater than zero and remains unchanged, the opening of the electric ball valve is controlled to decrease, and the opening required to be reduced by the electric ball valve decreases as the water-side temperature difference increases.

[0071] Among them, the change of the opening of the electric ball valve with the refrigerant temperature difference and the water side temperature difference in the above steps can refer to Table 1. For example, the current inlet water temperature is 10°C, the current outlet water temperature is 15°C, the target condensing temperature, i.e., the target outlet liquid temperature, is 25°C, the refrigerant temperature difference is 7°C, the initial opening of the electric ball valve is 25%, the opening of the electric ball valve is reduced by 6%, i.e., the opening is adjusted to 18%, and the next calculation is entered after 30s.

[0072] In addition, the opening of the electric ball valve can be uniformly decreased or uniformly increased, or can be variable-speed decreased or variable-speed increased, which is determined according to actual control requirements and is not limited here.

[0073] Step 290: When the water side temperature is lower than a preset low temperature threshold, the opening of the electric ball valve is controlled to be a preset large opening.

[0074] Step 291: When the water side temperature is higher than a preset high temperature threshold, the opening of the electric ball valve is controlled to be a preset small opening.

[0075] Exemplarily, the preset low temperature threshold and the preset high temperature threshold are 1.5 degrees Celsius and 15 degrees Celsius respectively. The preset large opening can be 100% or a value less than 100%, the preset small opening can be an opening greater than 0, and the preset low temperature threshold is lower than the preset high temperature threshold, and the preset large opening is greater than the preset small opening.

[0076] In addition, a temperature sensor is provided at the outlet of the compressor, which is used to collect the exhaust temperature of the compressor. If the exhaust temperature is greater than a certain value, such as 110°C, the electric ball valve is forced to open wide. To avoid affecting the system pressure, the adjustment rate of the electric ball valve is 3% / s, and the specific value of the increase in opening is not limited here. When step 290 or step 291 conflicts with the above-mentioned adjustment of the opening of the electric ball valve according to the exhaust temperature, the opening of the electric ball valve is adjusted according to the exhaust temperature first. If the water side temperature difference is detected to be less than a certain value, such as 0.5°C, for a period of time, such as 120s, it is determined that the compressor unit is shut down, and the electric ball valve needs to be immediately adjusted to the initial opening.

[0077] It should be noted that the numerical values ​​in Table 1 of this embodiment are only for illustrative purposes and can be determined according to the actual working requirements of the refrigeration system and the water system, and are not limited here.

[0078] The condensing pressure control method of the environmental test chamber provided in this embodiment controls the opening of the electric ball valve in real time to increase or decrease according to the determined water-side temperature difference and refrigerant temperature difference, thereby controlling the condensing pressure of the environmental test chamber, solving the problems of hysteresis and small adjustment range of the pressure regulating valve in the prior art, thereby ensuring control reliability.

[0079] Embodiment 3

[0080] Figure 3 This is a structural block diagram of a condensing pressure control device of an environmental test chamber provided in Example 3 of the present invention. The environmental test chamber includes a chamber body, a control system, a refrigeration system and a water system. The refrigeration system is located inside the chamber body. The control system includes a controller and a temperature sensor. The refrigeration system includes a compressor, a condenser, an evaporator and a throttling element. The water system includes an electric ball valve, a water outlet pipeline and a water inlet pipeline. The outlet of the compressor is connected to the liquid inlet of the condenser, the liquid outlet of the condenser is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the compressor, a throttling element is provided in the pipeline connecting the condenser and the evaporator, a temperature sensor is provided on the side of the water outlet pipeline and the water inlet pipeline close to the condenser, the electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is connected to the water outlet pipeline, the water inlet of the condenser is connected to the water inlet pipeline, the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected; refer to Figure 3 The condensing pressure control device includes: a temperature acquisition module 310, a temperature difference determination module 320 and an opening control module 330. The temperature acquisition module 310 is used to acquire the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser; the temperature difference determination module 320 is used to determine the water side temperature difference and the refrigerant temperature difference of the condenser according to the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature; the opening control module 330 is used to control the opening of the electric ball valve according to the water side temperature difference and the refrigerant temperature difference, so as to control the condensing pressure of the environmental test chamber.

[0081] Based on the above implementation, the temperature difference determination module 320 includes: a water side temperature difference determination unit and a refrigerant temperature difference determination unit; wherein the water side temperature difference determination unit is used to take the difference between the real-time water outlet temperature and the real-time water inlet temperature as the water side temperature difference; the refrigerant temperature difference determination unit is used to take the difference between the target liquid outlet temperature and the real-time liquid outlet temperature as the refrigerant temperature difference.

[0082] In one embodiment, the opening control module 330 includes a first control unit and a second control unit; wherein the first control unit is used to control the opening of the electric ball valve to increase or remain unchanged when the refrigerant temperature difference remains unchanged and the water side temperature difference increases; the second control unit is used to control the opening of the electric ball valve to decrease when the water side temperature difference remains unchanged and the refrigerant temperature difference increases.

[0083] Optionally, the opening control module 330 includes a third control unit and a fourth control unit; wherein the third control unit is used to control the opening of the electric ball valve to increase when the refrigerant temperature difference is less than zero; and the fourth control unit is used to control the opening of the electric ball valve to decrease when the refrigerant temperature difference is greater than zero.

[0084] Optionally, the opening control module 330 includes a fifth control unit, a sixth control unit, a seventh control unit and an eighth control unit; wherein the fifth control unit is used to control the opening of the electric ball valve to increase when the refrigerant temperature difference is less than zero and the water side temperature difference remains unchanged, and the opening required to be increased by the electric ball valve decreases as the refrigerant temperature difference increases; the sixth control unit is used to control the opening of the electric ball valve to decrease when the refrigerant temperature difference is greater than zero and the water side temperature difference remains unchanged, and the opening required to be reduced by the electric ball valve increases as the refrigerant temperature difference increases; the seventh control unit is used to control the opening of the electric ball valve to increase when the refrigerant temperature difference is less than zero and the refrigerant temperature difference remains unchanged, and the opening required to be increased by the electric ball valve increases as the water side temperature difference increases; the eighth control unit is used to control the opening of the electric ball valve to decrease when the refrigerant temperature difference is greater than zero and the refrigerant temperature difference remains unchanged, and the opening required to be reduced by the electric ball valve decreases as the water side temperature difference increases.

[0085] Optionally, the opening control module 330 includes a ninth control unit and a tenth control unit; wherein the ninth control unit is used to control the opening of the electric ball valve to a preset large opening when the water side temperature is lower than a preset low temperature threshold; the tenth control unit is used to control the opening of the electric ball valve to a preset small opening when the water side temperature is higher than a preset high temperature threshold.

[0086] Optionally, the above-mentioned condensing pressure control device also includes an initial opening determination module, which is used to determine the initial opening of the electric ball valve according to the real-time inlet water temperature after the temperature acquisition module obtains the real-time inlet water temperature, real-time outlet water temperature and real-time outlet liquid temperature of the condenser.

[0087] The condensation pressure control device of the environmental test chamber provided in this embodiment and the condensation pressure control method of the environmental test chamber provided in any embodiment of the present invention belong to the same inventive concept and have corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the condensation pressure control method of the environmental test chamber provided in any embodiment of the present invention.

[0088] Embodiment 4

[0089] Figure 4 Schematic diagram of a partial structure of an environmental test chamber provided by Embodiment 4 of the present invention. Figure 4 The environmental test box includes: a box body (not shown in the figure), a control system, a refrigeration system and a water system. The refrigeration system is located inside the box body. The control system includes a controller (not shown in the figure) and temperature sensors T1, T2, and T3. The refrigeration system includes a compressor 10, a condenser 20, an evaporator 30, and a throttling element 40. The water system includes an electric ball valve 50, a water outlet pipeline 60, and a water inlet pipeline 70. The outlet of the compressor 10 is connected to the liquid inlet of the condenser 20, the liquid outlet of the condenser 20 is connected to the inlet of the evaporator 30, the outlet of the evaporator 30 is connected to the inlet of the compressor 10, and a water inlet pipeline 70 is provided in the pipeline connecting the condenser 20 and the evaporator 30. A throttling element 40 is provided, and temperature sensors T1 and T2 are respectively provided on the side of the water outlet pipe 60 and the water inlet pipe 70 close to the condenser 20, and an electric ball valve 50 is located in the water outlet pipe 60, the water outlet of the condenser 20 is connected to the water outlet pipe 60, the water inlet of the condenser 20 is connected to the water inlet pipe 70, and a temperature sensor T3 is provided on the side close to the liquid outlet of the condenser 20 in the pipe connected to the liquid outlet of the condenser 20, and the temperature sensors T1, T2, T3, the compressor 10, the throttling element 40, and the electric ball valve 50 are electrically connected to the controller; the condensing pressure control device of the environmental test box provided in any embodiment of the present invention is integrated in the controller. Among them, the side of the water outlet pipe 60 and the water inlet pipe 70 away from the condenser 20 is connected to the cooling tower, and a temperature sensor is provided at the outlet of the compressor 10. The controller is used to control the working state of the compressor and control the opening of the electric ball valve according to the temperature collected by each temperature sensor. The specific control process of the controller on the opening of the electric ball valve can refer to any of the above embodiments and will not be repeated here.

[0090] Furthermore, the refrigeration system includes two subsystems, each of which includes a compressor, a condenser, an evaporator, and a throttling element. The compressor of one subsystem is a low-temperature side compressor, and the compressor of the other subsystem is a high-temperature side compressor. The two subsystems are connected via a plate heat exchanger 100. Figure 4 The middle compressor 10 is a high temperature side compressor.

[0091] Optionally, a water pressure gauge 80 is provided in both the water inlet pipeline and the water outlet pipeline, and a water pressure protector 90 is also provided in the water inlet pipeline. The water pressure gauge 80 can measure and display the water pressure of the pipeline, and the water pressure protector 90 performs water pressure protection on the pipeline.

[0092] The refrigeration system provided in this embodiment and the condensing pressure control method of the environmental test chamber provided in any embodiment of the present invention belong to the same inventive concept and have corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the condensing pressure control method of the environmental test chamber provided in any embodiment of the present invention.

[0093] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for controlling the condensation pressure of an environmental test chamber, characterized in that: The environmental test box includes a box body, a control system, a refrigeration system and a water system. The refrigeration system is located inside the box body. The control system includes a controller and a temperature sensor. The refrigeration system includes a compressor, a condenser, an evaporator and a throttling element. The water system includes an electric ball valve, a water outlet pipeline and a water inlet pipeline. The outlet of the compressor is communicated with the liquid inlet of the condenser, the liquid outlet of the condenser is communicated with the inlet of the evaporator, the outlet of the evaporator is communicated with the inlet of the compressor, the throttling element is arranged in the pipeline connecting the condenser and the evaporator, the temperature sensor is arranged on the side of the water outlet pipeline and the water inlet pipeline close to the condenser, the electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is communicated with the water outlet pipeline, the water inlet of the condenser is communicated with the water inlet pipeline, and the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected; The condensing pressure control method is executed by the controller, and the condensing pressure control method includes: Obtaining the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser; Determine the water side temperature difference and the refrigerant temperature difference of the condenser according to the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature; The opening of the electric ball valve is controlled according to the water-side temperature difference and the refrigerant temperature difference to control the condensing pressure of the environmental test box.

2. The condensing pressure control method according to claim 1, characterized in that: The determining the water side temperature difference and the refrigerant temperature difference of the condenser according to the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature comprises: The difference between the real-time water outlet temperature and the real-time water inlet temperature is used as the water side temperature difference; The difference between the target liquid outlet temperature and the real-time liquid outlet temperature is used as the refrigerant temperature difference.

3. The condensing pressure control method according to claim 1, characterized in that: The step of controlling the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference comprises: When the refrigerant temperature difference remains unchanged and the water-side temperature difference increases, controlling the opening of the electric ball valve to increase or remain unchanged; When the water-side temperature difference remains unchanged and the refrigerant temperature difference increases, the opening of the electric ball valve is controlled to decrease.

4. The condensing pressure control method according to claim 1, characterized in that: The step of controlling the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference comprises: When the refrigerant temperature difference is less than zero, controlling the opening of the electric ball valve to increase; When the refrigerant temperature difference is greater than zero, the opening of the electric ball valve is controlled to decrease.

5. The condensing pressure control method according to claim 1, characterized in that: The step of controlling the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference comprises: When the refrigerant temperature difference is less than zero and the water-side temperature difference remains unchanged, the opening of the electric ball valve is controlled to increase, and the opening required to be increased by the electric ball valve decreases as the refrigerant temperature difference increases; When the refrigerant temperature difference is greater than zero and the water-side temperature difference remains unchanged, the opening of the electric ball valve is controlled to decrease, and the opening required to be reduced by the electric ball valve increases as the refrigerant temperature difference increases; When the refrigerant temperature difference is less than zero and the refrigerant temperature difference remains unchanged, the opening of the electric ball valve is controlled to increase, and the opening required to be increased by the electric ball valve increases with the increase of the water-side temperature difference; When the refrigerant temperature difference is greater than zero and remains unchanged, the opening of the electric ball valve is controlled to decrease, and the opening required to be reduced by the electric ball valve decreases as the water-side temperature difference increases.

6. The condensing pressure control method according to claim 1, characterized in that: The step of controlling the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference comprises: When the water side temperature is lower than a preset low temperature threshold, the opening of the electric ball valve is controlled to be a preset large opening; When the water side temperature is higher than a preset high temperature threshold, the opening of the electric ball valve is controlled to be a preset small opening.

7. The condensing pressure control method according to claim 1, characterized in that: After obtaining the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser, the method further includes: The initial opening of the electric ball valve is determined according to the real-time water inlet temperature.

8. A condensation pressure control device for an environmental test chamber, characterized in that: The environmental test box includes a box body, a control system, a refrigeration system and a water system. The refrigeration system is located inside the box body. The control system includes a controller and a temperature sensor. The refrigeration system includes a compressor, a condenser, an evaporator and a throttling element. The water system includes an electric ball valve, a water outlet pipeline and a water inlet pipeline. The outlet of the compressor is communicated with the liquid inlet of the condenser, the liquid outlet of the condenser is communicated with the inlet of the evaporator, the outlet of the evaporator is communicated with the inlet of the compressor, the throttling element is arranged in the pipeline connecting the condenser and the evaporator, the temperature sensor is arranged on the side of the water outlet pipeline and the water inlet pipeline close to the condenser, the electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is communicated with the water outlet pipeline, the water inlet of the condenser is communicated with the water inlet pipeline, and the temperature sensor, the compressor, the throttling element, the electric ball valve and the controller are electrically connected; The condensing pressure control device comprises: A temperature acquisition module, used to acquire the real-time water inlet temperature, real-time water outlet temperature and real-time liquid outlet temperature of the condenser; a temperature difference determination module, for determining a water side temperature difference and a refrigerant temperature difference of the condenser according to the real-time water inlet temperature, the real-time water outlet temperature and the real-time liquid outlet temperature; The opening control module is used to control the opening of the electric ball valve according to the water-side temperature difference and the refrigerant temperature difference, so as to control the condensing pressure of the environmental test box.

9. An environmental test chamber, characterized in that: include: A box body, a control system, a refrigeration system and a water system, wherein the refrigeration system is located inside the box body, the control system includes a controller and a temperature sensor, the refrigeration system includes a compressor, a condenser, an evaporator and a throttling element, and the water system includes an electric ball valve, a water outlet pipeline and a water inlet pipeline; the outlet of the compressor is connected to the liquid inlet of the condenser, the liquid outlet of the condenser is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the compressor, the throttling element is arranged in the pipeline connecting the condenser and the evaporator, the temperature sensor is arranged on the side of the water outlet pipeline and the water inlet pipeline close to the condenser, the electric ball valve is located in the water outlet pipeline, the water outlet of the condenser is connected to the water outlet pipeline, the water inlet of the condenser is connected to the water inlet pipeline, the temperature sensor, the compressor, the throttling element, the electric ball valve are electrically connected to the controller; the condensing pressure control device as claimed in claim 7 is integrated in the controller.

10. The environmental test chamber according to claim 9, characterized in that: The water inlet pipeline and the water outlet pipeline are both provided with water pressure gauges, and the water inlet pipeline is also provided with a water pressure protector.

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