Low-temperature air dehumidification device for vehicle low-temperature simulation test

Abstract

The utility model relates to the technical field of low-temperature air dehumidification, and discloses a low-temperature air dehumidification device for a vehicle low-temperature simulation test, which comprises an air compressor and a heat exchanger, the air compressor is provided with an air inlet and an air outlet, the heat exchanger is provided with a low-temperature air inlet and a low-temperature air outlet, and the low-temperature air outlet is communicated with the air inlet. The heat exchanger is provided with a high-temperature air inlet and a high-temperature air outlet, and the high-temperature air inlet is communicated with the air outlet, so that the air enters the heat exchanger after being compressed and heated by the air compressor. When the low-temperature air dehumidification device works, the situation that a regeneration area needs to be heated is avoided, meanwhile, low-temperature air in the whole environment bin does not need to be replaced, the low-temperature air does not need to be heated to the normal temperature, then fresh air does not need to be replaced to the low humidity, and finally the temperature is reduced to the low temperature, and huge energy consumption in the whole circulation process is reduced; the cost of the low-temperature simulation test of the vehicle is reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of air dehumidification, and specifically relates to a low-temperature air dehumidification device for low-temperature simulation testing of vehicles. Background Art

[0002] When a vehicle undergoes a low-temperature environment simulation test, an environmental chamber system is required. During operation, the environmental chamber system needs to continuously replenish fresh air to supply the engine for combustion. The water vapor introduced by fresh air, exhaust leakage, and air leakage from gaps is difficult to remove at low temperatures. Water vapor continues to accumulate in the chamber, causing the air to be in a high-humidity state, which will form ice on the surface of the precision testing equipment. Once the temperature is higher than 0°C, it will melt into water and cause equipment damage.

[0003] In order to increase the service life of the equipment, a rotary dehumidifier is usually used to dehumidify the low-temperature and high-humidity air in the environmental chamber system. The rotary dehumidifier is a device that uses a rotary wheel made of solid desiccant for rotating dehumidification. The wheel is covered with honeycomb flow channels. When the air flows through these flow channels, it exchanges heat and moisture with the flow channel walls. The flow channel walls themselves contain solid desiccant. When it is cooled by the air, its corresponding water vapor partial pressure is less than the water vapor partial pressure of the treated air, and the water vapor is adsorbed into the desiccant. At the same time, the sensible heat of the rotor itself and the adsorption heat generated by the adsorption increase the air temperature. As the wheel rotates, the moisture absorption of this part of the flow channel gradually reaches saturation. When these moisture-absorbed flow channels rotate to the regeneration zone, hot air flows through these honeycomb flow channels, and the flow channel wall containing the solid desiccant is heated. Its corresponding water vapor partial pressure is higher than the water vapor partial pressure in the regeneration air, which drives out the moisture in the desiccant. As the wheel rotates and desorption proceeds, the honeycomb desiccant flow channel restores its moisture absorption capacity and is rotated to the dehumidification zone again. This cycle repeats itself, and the dehumidification process can be carried out continuously. However, since the regeneration zone of the wheel needs to be heated to a higher temperature to achieve the regeneration effect, the energy consumption of the rotary dehumidifier is high, which in turn increases the cost of the low-temperature simulation test. Utility Model Content

[0004] The present application provides a low-temperature air dehumidification device for a low-temperature simulation test of a vehicle, so as to reduce the cost of the low-temperature simulation test.

[0005] The technical solution adopted in this application is:

[0006] A low-temperature air dehumidification device for low-temperature simulation tests of vehicles includes an air compressor and a heat exchanger, the air compressor having an air inlet and an air outlet, the heat exchanger having a low-temperature air inlet and a low-temperature air outlet, the low-temperature air outlet being connected to the air inlet so that air enters the air compressor through the heat exchanger under the action of the air compressor, the heat exchanger also having a high-temperature air inlet and a high-temperature air outlet, the high-temperature air inlet being connected to the air outlet so that air enters the heat exchanger after being compressed and heated by the air compressor.

[0007] By adopting the above-mentioned technical scheme, when using the low-temperature air dehumidification device in the present application, the air compressor is started, and a negative pressure is formed at the air inlet of the air compressor, so that the low-temperature and high-humidity air in the environmental chamber system enters the heat exchanger through the low-temperature air inlet and enters the air compressor through the heat exchanger and the low-temperature air outlet, and then the air compressor compresses the low-temperature and high-humidity air and heats the low-temperature and high-humidity air at the same time. After being compressed and heated by the air compressor, the low-temperature and high-humidity air enters the heat exchanger through the air outlet and the high-temperature air inlet. The temperature difference between the low-temperature and high-humidity air and the compressed air in the heat exchanger causes the low-temperature and high-humidity air to exchange heat with the compressed air and produce liquid condensed water to achieve drying of the low-temperature and high-humidity air. At the same time, the compressed air re-enters the environmental chamber through the high-temperature air outlet, so as to control the pressure difference between the inside and outside of the environmental chamber.

[0008] When the low-temperature air dehumidification device is working, it only needs to power on the air compressor. There is no need to set up a separate heating module to heat the low-temperature and high-humidity air, avoiding the need to heat the regeneration area. At the same time, there is no need to replace the low-temperature air in the entire environmental chamber, and there is no need to heat the low-temperature air to room temperature, replace fresh air to low humidity, and finally cool it to low temperature, which reduces the huge energy consumption of the entire cycle process and reduces the cost of vehicle low-temperature simulation tests.

[0009] Moreover, when the low-temperature air dehumidification device is working, the normal operation of the environmental chamber is not affected, and the two can run simultaneously without interfering with each other. Compared with the rotary dehumidifier, it can save the time required for separate dehumidification each time, thereby greatly reducing the working time of the tester.

[0010] Optionally, the high-temperature air outlet is connected to a pressure-holding valve.

[0011] By adopting the above technical solution, when the low-temperature air dehumidification device in this application is working, air compression will generate a certain heat load on the environmental chamber, but after the pressure is reduced by the pressure-holding valve and the air temperature will drop, compared with the adsorption process of the rotary dehumidifier, which is water vapor condensation and heat release, the air temperature will rise. The low-temperature air dehumidification device generates less heat load on the environmental chamber, which is conducive to the stable operation temperature of the environmental chamber. At the same time, the setting of the pressure-holding valve can make the air entering the heat exchanger through the air outlet maintain a certain pressure, so as to ensure the heat exchange effect between the air entering the heat exchanger through the air outlet and the low-temperature and high-humidity air, thereby ensuring the dehumidification effect.

[0012] Optionally, a three-way pipeline is arranged between the air compressor and the heat exchanger, and the three-way pipeline has an air inlet end and two air outlet ends. The air inlet end is connected to the air outlet, one of the air outlet ends is connected to the high-temperature air inlet, and the other air outlet end is connected to a thermal expansion valve, and the temperature sensing package of the thermal expansion valve is arranged at the high-temperature air outlet.

[0013] By adopting the above technical solution, the temperature sensing package adjusts the opening of the thermal expansion valve by measuring the temperature at the high-temperature air outlet, so that the compressed air can be reduced to normal pressure through the thermal expansion valve and then return to the environmental chamber, so that the temperature at the high-temperature air outlet is lower than the pressure dew point temperature, so as to ensure the dehumidification effect of low-temperature and high-humidity air.

[0014] Optionally, the pressure-holding valve is connected to the high-temperature air outlet via an air outlet pipeline, and the temperature-sensing package of the thermal expansion valve is arranged on the air outlet pipeline.

[0015] By adopting the above technical solution, the pressure-holding valve is connected to the high-temperature air outlet through the air outlet pipeline, and the temperature-sensing bag of the thermal expansion valve is arranged in the air outlet pipeline, so that the air flowing out through the high-temperature air outlet first passes through the temperature-sensing bag and then passes through the pressure-holding valve, so that the temperature-sensing bag is closer to the high-temperature air outlet, so that the temperature-sensing bag can accurately control the opening of the thermal expansion valve, thereby ensuring the dehumidification effect of low-temperature and high-humidity air.

[0016] Optionally, the heat exchanger includes a shell and a heat exchange tube arranged in the shell, the two ports of the heat exchange tube are the low-temperature air inlet and the low-temperature air outlet, and the high-temperature air inlet and the high-temperature air outlet are respectively arranged at two opposite ends of the shell.

[0017] By adopting the above technical solution, when the low-temperature air dehumidification device is working, the low-temperature and high-humidity air in the environmental chamber enters the heat exchange tube, and the air compressed and heated by the air compressor enters the shell, and then forms liquid condensed water on the outer wall of the heat exchange tube, so that the liquid condensed water can be discharged from the heat exchanger. At the same time, the high-temperature air inlet and the high-temperature air outlet are respectively arranged at the two opposite ends of the shell, which can increase the flow path of the compressed air in the heat exchanger, increase the residence time of the compressed air in the heat exchanger, and thus increase the heat exchange effect between the compressed air and the low-temperature and high-humidity air in the heat exchange tube, so as to further ensure the dehumidification effect of the low-temperature and high-humidity air.

[0018] Optionally, the shell has a drain port, and a drain valve is provided at the drain port.

[0019] By adopting the above technical solution, after the low-temperature air dehumidification device has been used for a period of time, the drain valve is opened to allow the liquid condensed water in the shell to be discharged through the drain port and the drain valve, so as to clean the liquid condensed water in the shell, thereby ensuring normal dehumidification of the low-temperature and high-humidity air.

[0020] Optionally, the shell has a liquid collecting portion that is recessed downward, and the liquid discharge port is arranged in the liquid collecting portion.

[0021] By adopting the above technical solution, the liquid collecting part is recessed downward and the liquid discharge port is arranged in the liquid collecting part. On the one hand, the capacity inside the shell can be increased to increase the volume of liquid condensed water that can be accommodated in the shell. On the other hand, when the liquid condensed water in the shell is discharged, the liquid collecting part can also guide the liquid condensed water so as to drain the liquid condensed water in the shell.

[0022] Optionally, the bottom wall of the shell is arranged to be inclined downward along the direction from the high-temperature air inlet to the high-temperature air outlet, and the liquid collecting portion is arranged at one end of the shell close to the high-temperature air outlet.

[0023] By adopting the above technical solution, since the bottom wall of the shell is inclined downward along the direction from the high-temperature air inlet to the high-temperature air outlet, and the liquid collecting part is arranged at one end of the shell close to the high-temperature air outlet, the guiding effect of the liquid collecting part on the liquid condensed water is further increased, thereby further facilitating the drainage of the liquid condensed water in the shell.

[0024] Optionally, a water collecting tank is provided in communication with the drain valve, so that condensed water in the shell enters the water collecting tank through the drain valve.

[0025] By adopting the above technical solution, when the liquid condensed water in the shell is discharged, the liquid condensed water enters the water collecting tank through the drain valve, so that the liquid condensed water is collected in the water collecting tank, so that the liquid condensed water can be utilized or subsequently processed.

[0026] Optionally, a one-way valve is provided at the top of the water collecting tank, so that when condensed water enters the water collecting tank, the air in the water collecting tank is discharged through the one-way valve.

[0027] By adopting the above technical solution, when liquid condensate enters the water collecting tank, the air in the water collecting tank is discharged through the one-way valve to balance the pressure in the water collecting tank with the outside world, thereby ensuring that the condensate in the shell enters the water collecting tank smoothly, and at the same time avoiding the situation where the compressed air in the shell enters the water collecting tank and causes expansion and damage of the water collecting tank, thereby increasing the service life of the water collecting tank.

[0028] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows:

[0029] 1. The low-temperature air dehumidification device in the present application includes an air compressor and a heat exchanger. The air compressor has an air inlet and an air outlet. The heat exchanger has a low-temperature air inlet and a low-temperature air outlet. The low-temperature air outlet is connected to the air inlet so that air enters the air compressor through the heat exchanger under the action of the air compressor. The heat exchanger also has a high-temperature air inlet and a high-temperature air outlet. The high-temperature air inlet is connected to the air outlet so that air enters the heat exchanger after being compressed and heated by the air compressor, so that the low-temperature and high-humidity air exchanges heat with the air discharged from the air machine and generates liquid condensed water to achieve low-temperature The high-humidity air is dried, and the air after heat exchange with the low-temperature and high-humidity air re-enters the environmental chamber through the high-temperature air outlet, so as to control the pressure difference between the inside and outside of the environmental chamber; at the same time, it is only necessary to power on the air compressor, and there is no need to set up a separate heating module to heat the low-temperature and high-humidity air, thus avoiding the need to heat the regeneration area. At the same time, there is no need to replace the low-temperature air in the entire environmental chamber, and there is no need to heat the low-temperature air to room temperature, and then replace it with fresh air to low humidity, and finally cool it to low temperature, thereby reducing the huge energy consumption of the entire cycle process, so as to reduce the cost of vehicle low-temperature simulation tests.

[0030] 2. The high-temperature air outlet in this application is connected to a pressure-holding valve. When the low-temperature air dehumidification device in this application is working, air compression will generate a certain heat load on the environmental chamber, but after the pressure is reduced by the pressure-holding valve and approximately isentropic expansion, the air temperature will drop. Compared with the adsorption process of the rotary dehumidifier, which is water vapor condensation and heat release, the air temperature will rise. The low-temperature air dehumidification device generates less heat load on the environmental chamber, which is conducive to the stability of the operating temperature of the environmental chamber. At the same time, the setting of the pressure-holding valve can keep a certain pressure on the air entering the heat exchanger through the air outlet, so as to ensure the heat exchange effect between the air entering the heat exchanger through the air outlet and the low-temperature and high-humidity air, thereby ensuring the dehumidification effect.

[0031] 3. In the present application, a three-way pipeline is arranged between the air compressor and the heat exchanger. The three-way pipeline has an air inlet end and two air outlet ends. The air inlet end is connected to the air outlet, one of the air outlet ends is connected to the high-temperature air inlet, and the other air outlet end is connected to a thermal expansion valve. The temperature sensing package of the thermal expansion valve is arranged at the high-temperature air outlet. The temperature sensing package adjusts the opening of the thermal expansion valve by measuring the temperature at the high-temperature air outlet, so that the compressed air can be reduced to normal pressure through the thermal expansion valve and then return to the environmental chamber, so that the temperature at the high-temperature air outlet is lower than the pressure dew point temperature, so as to ensure the dehumidification effect of the low-temperature and high-humidity air. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0033] Figure 1 This is a schematic structural diagram of the low-temperature air dehumidification device according to one embodiment of the present application, wherein the solid arrow indicates the flow direction of the low-temperature and high-humidity air, and the dotted arrow indicates the flow direction of the compressed air.

[0034] Reference numerals:

[0035] 1. Air compressor; 2. Heat exchanger; 21. Shell; 211. Drain valve; 22. Heat exchange tube; 3. Pressure holding valve; 4. Thermal expansion valve; 41. Temperature sensing package. DETAILED DESCRIPTION

[0036] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below. It should be noted that the embodiments of the present application and the features in each embodiment may be combined with each other without conflict.

[0038] In addition, in the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0039] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0041] Reference Figure 1 A low-temperature air dehumidification device for a vehicle low-temperature simulation test includes an air compressor 1 and a heat exchanger 2. The air compressor 1 has an air inlet and an air outlet. The heat exchanger 2 has a low-temperature air inlet and a low-temperature air outlet. The low-temperature air outlet is connected to the air inlet so that the air enters the air compressor 1 through the heat exchanger 2 under the action of the air compressor 1. The heat exchanger 2 also has a high-temperature air inlet and a high-temperature air outlet. The high-temperature air inlet is connected to the air outlet so that the air enters the heat exchanger 2 after being compressed and heated by the air compressor 1.

[0042] When using the low-temperature air dehumidification device in the present application, start the air compressor 1, and a negative pressure is formed at the air inlet of the air compressor 1, so that the low-temperature and high-humidity air in the environmental chamber system enters the heat exchanger 2 through the low-temperature air inlet and enters the air compressor 1 through the heat exchanger 2 and the low-temperature air outlet, and then the air compressor 1 compresses the low-temperature and high-humidity air and heats the low-temperature and high-humidity air at the same time. After being compressed and heated by the air compressor 1, the low-temperature and high-humidity air enters the heat exchanger 2 through the air outlet and the high-temperature air inlet. The temperature difference between the low-temperature and high-humidity air in the heat exchanger 2 and the air discharged through the air compressor 1 causes the low-temperature and high-humidity air to exchange heat with the air discharged through the air machine and produce liquid condensed water, so as to achieve drying of the low-temperature and high-humidity air. At the same time, the air after heat exchange with the low-temperature and high-humidity air re-enters the environmental chamber through the high-temperature air outlet, so as to control the pressure difference between the inside and outside of the environmental chamber.

[0043] It should be noted that after the low-temperature and high-humidity air is compressed, the water vapor partial pressure will increase, and the pressure dew point temperature of the compressed air will be higher than the dew point temperature under atmospheric pressure. The temperature difference between the low-temperature and high-humidity air in the heat exchanger 2 and the air entering the heat exchanger 2 through the air outlet can compress the low-temperature and high-humidity air to a state where the pressure dew point temperature is higher than 0°C, thereby solving the problem that water vapor directly condenses into ice and is difficult to separate during the dehumidification process of the low-temperature and high-humidity air.

[0044] Dew point temperature: refers to the temperature to which the water vapor in the air reaches saturation and condenses into liquid water when the air water vapor content and air pressure are constant. Pressure dew point temperature: Usually, unless otherwise specified, the dew point refers to the atmospheric pressure dew point. However, if the air is compressed, the dew point will rise, and the dew point at this time is called the pressure dew point.

[0045] When the low-temperature air dehumidification device is working, it only needs to power on the air compressor 1. There is no need to set up a separate heating module to heat the low-temperature and high-humidity air, which avoids the need to heat the regeneration zone. At the same time, there is no need to replace the low-temperature air in the entire environmental chamber, and there is no need to heat the low-temperature air to room temperature, replace fresh air to low humidity, and finally cool it to low temperature, which reduces the huge energy consumption of the entire cycle process, thereby reducing the cost of vehicle low-temperature simulation tests.

[0046] Moreover, when the low-temperature air dehumidification device is working, the normal operation of the environmental chamber is not affected, and the two can run simultaneously without interfering with each other. Compared with the rotary dehumidifier, it can save the time required for separate dehumidification each time, thereby greatly reducing the working time of the tester.

[0047] In a preferred embodiment, the high-temperature air outlet is connected to a pressure-maintaining valve 3 .

[0048] When the low-temperature air dehumidification device in this application is working, air compression will generate a certain heat load on the environmental chamber, but after the pressure is reduced by the pressure-holding valve 3 and the air temperature will drop, compared with the adsorption process of the rotary dehumidifier, which is the heat release of water vapor condensation, the air temperature will rise. The low-temperature air dehumidification device generates less heat load on the environmental chamber, which is conducive to the stability of the operating temperature of the environmental chamber. At the same time, the setting of the pressure-holding valve 3 can make the air entering the heat exchanger 2 through the air outlet maintain a certain pressure, so as to ensure the heat exchange effect between the air entering the heat exchanger 2 through the air outlet and the low-temperature and high-humidity air, and then ensure the dehumidification effect.

[0049] In a preferred embodiment, a three-way pipeline is arranged between the air compressor 1 and the heat exchanger 2, and the three-way pipeline has an air inlet end and two air outlet ends. The air inlet end is connected to the air outlet, one of the air outlet ends is connected to the high-temperature air inlet, and the other air outlet end is connected to a thermal expansion valve 4, and the temperature sensing bag 41 of the thermal expansion valve 4 is arranged at the high-temperature air outlet.

[0050] The temperature sensing package 41 adjusts the opening of the thermal expansion valve 4 by measuring the temperature at the high-temperature air outlet, so that the air flowing out through the air outlet can be reduced to normal pressure through the thermal expansion valve 4 and then return to the environmental chamber, so that the temperature at the high-temperature air outlet is lower than the pressure dew point temperature, so as to ensure the dehumidification effect of the low-temperature and high-humidity air.

[0051] Furthermore, the pressure-holding valve 3 is connected to the high-temperature air outlet through an air outlet pipeline, and the temperature-sensing package 41 of the thermal expansion valve 4 is arranged on the air outlet pipeline.

[0052] The pressure-holding valve 3 is connected to the high-temperature air outlet through an air outlet pipeline, and the temperature-sensing bag 41 of the thermal expansion valve 4 is arranged in the air outlet pipeline, so that the air flowing out through the high-temperature air outlet first passes through the temperature-sensing bag 41 and then passes through the pressure-holding valve 3, so that the temperature-sensing bag 41 is closer to the high-temperature air outlet, so that the temperature-sensing bag 41 can accurately control the opening of the thermal expansion valve 4, thereby ensuring the dehumidification effect of the low-temperature and high-humidity air.

[0053] Preferably, the pressure-supplying valve 3 and the thermal expansion valve 4 are connected via a three-way interface, that is, the two air inlet interfaces of the three-way interface are respectively connected to the pressure-supplying valve 3 and the thermal expansion valve 4, so that the air flowing out through the pressure-supplying valve 3 and the thermal expansion valve 4 is discharged through an air outlet interface of the three-way interface, so as to control the flow direction of the air.

[0054] The present application does not make any specific limitation on the structure of the heat exchanger 2. Preferably, the heat exchanger 2 includes a shell 21 and a heat exchange tube 22 arranged in the shell 21. The two ports of the heat exchange tube 22 are respectively a low-temperature air inlet and a low-temperature air outlet, and the high-temperature air inlet and the high-temperature air outlet are respectively arranged at two opposite ends of the shell 21.

[0055] When the low-temperature air dehumidification device is working, the low-temperature and high-humidity air in the environmental chamber enters the heat exchange tube 22, and the air compressed and heated by the air compressor 1 enters the shell 21, and then forms liquid condensed water on the outer wall of the heat exchange tube 22, so that the liquid condensed water can be discharged from the heat exchanger 2. At the same time, the high-temperature air inlet and the high-temperature air outlet are respectively arranged at the opposite ends of the shell 21, which can increase the flow path of the compressed air in the heat exchanger 2, so as to increase the residence time of the compressed air in the heat exchanger 2, thereby increasing the heat exchange effect between the compressed air and the low-temperature and high-humidity air in the heat exchange tube 22, so as to further ensure the dehumidification effect of the low-temperature and high-humidity air.

[0056] In a preferred embodiment, an insulation layer is provided on the outside of the shell 21 to ensure the temperature of the compressed air and avoid heat exchange between the compressed air and the low-temperature and high-humidity air outside the shell 21 that has not entered the heat exchanger 2, thereby ensuring the dehumidification effect of the low-temperature and high-humidity air.

[0057] The present application does not specifically limit the structure of the thermal insulation layer, which may be formed by thermal insulation cotton disposed outside the shell 21 , or may be formed by a foam board disposed outside the shell 21 .

[0058] In a preferred embodiment, the housing 21 has a liquid discharge port, and a liquid discharge valve 211 is provided at the liquid discharge port.

[0059] After the low-temperature air dehumidification device has been used for a period of time, the drain valve 211 is opened to discharge the liquid condensed water in the shell 21 through the drain port and the drain valve 211 to clean the liquid condensed water in the shell 21, thereby ensuring normal dehumidification of the low-temperature and high-humidity air.

[0060] Furthermore, the housing 21 has a liquid collecting portion that is recessed downward, and the liquid discharge port is provided in the liquid collecting portion.

[0061] The liquid collecting portion is recessed downward and the liquid discharge port is arranged in the liquid collecting portion. On the one hand, it can increase the capacity inside the shell 21 to increase the volume of liquid condensed water that can be accommodated in the shell 21. On the other hand, when the liquid condensed water in the shell 21 is discharged, the liquid collecting portion can also guide the liquid condensed water so as to drain the liquid condensed water in the shell 21.

[0062] Furthermore, the bottom wall of the shell 21 is arranged to be inclined downward in the direction from the high-temperature air inlet to the high-temperature air outlet, and the liquid collecting portion is arranged at one end of the shell 21 close to the high-temperature air outlet.

[0063] Since the bottom wall of the shell 21 is inclined downward along the direction from the high-temperature air inlet to the high-temperature air outlet, and the liquid collecting portion is arranged at one end of the shell 21 close to the high-temperature air outlet, the guiding effect of the liquid collecting portion on the liquid condensed water is further increased, thereby further facilitating the drainage of the liquid condensed water in the shell 21.

[0064] Preferably, a water collecting tank is provided in communication with the drain valve 211 , so that the condensed water in the housing 21 enters the water collecting tank through the drain valve 211 .

[0065] When the liquid condensed water in the shell 21 is discharged, the liquid condensed water enters the water collecting tank through the drain valve 211, so that the liquid condensed water is collected in the water collecting tank, so as to be utilized or subsequently processed.

[0066] Furthermore, a one-way valve is provided at the top of the water collecting tank, so that when condensed water enters the water collecting tank, the air in the water collecting tank is discharged through the one-way valve.

[0067] When liquid condensate enters the water collecting tank, the air in the water collecting tank is discharged through the one-way valve to balance the pressure in the water collecting tank with the outside world, thereby ensuring that the condensate in the shell 21 enters the water collecting tank smoothly. At the same time, it avoids the situation where the water collecting tank is expanded and damaged due to the air in the shell 21 entering the water collecting tank, thereby increasing the service life of the water collecting tank.

[0068] In other embodiments, the heat exchanger 2 may further include a box body, and a partition is provided inside the box body so that the partition divides the internal space of the box body into a low-temperature chamber and a high-temperature chamber.

[0069] In order to facilitate understanding of the solution of the present application, an example is now given. If the typical operating parameters of the environmental chamber test room that require dehumidification, a dry-bulb temperature of -20°C and a relative humidity of 70%, are taken as an example for calculation, the dew point temperature is queried to be -23.61°C.

[0070] According to the relationship curve between pressure dew point and atmospheric dew point in Appendix B Figure B.1 of "GB / T 4830-2015 Air Source Pressure Range and Quality for Industrial Automation Instruments", if wet air with an absolute pressure of 0.1MPa and a atmospheric dew point of -23℃ needs to obtain a pressure dew point slightly higher than 0℃ and with a certain degree of superheat, it should be pressurized to an absolute pressure of 0.8MPa. At this pressure, the pressure dew point is about 2℃.

[0071] When the existing dehumidification function of the environmental chamber is in operation, the low-temperature air is directly discharged without energy recovery. The low-temperature air dehumidification device recovers energy in the following way: compressed air with an absolute pressure of 0.8MPa is heat exchanged with air at a normal pressure and a low temperature of -20°C, and the temperature of the compressed air is reduced to a pressure dew point of 2°C below and above 0°C, so that the water vapor in the compressed air can be condensed into liquid water, and then the liquid water is discharged using the drain valve 211.

[0072] If the temperature of the compressed air with an absolute pressure of 0.8MPa cannot be reduced to a pressure dew point below 2°C, condensed water cannot be generated and dehumidification cannot be performed. At this time, it is necessary to open the thermal expansion valve 4 according to the temperature of the compressed air so that part of the air flowing out through the air outlet directly enters the environmental chamber to reduce the flow of compressed air entering the heat exchanger 2. When the air flow at normal pressure and low temperature of -20°C remains unchanged, the temperature of the compressed air at the outlet of the heat exchanger is reduced to below 2°C.

[0073] When the environmental chamber has other operating parameters that require dehumidification, such as the dry bulb temperature remains unchanged at -20℃ and the relative humidity is greater than 70%, the dew point temperature will increase with the increase of relative humidity. According to the relationship curve between the pressure dew point and the atmospheric pressure dew point, the pressure dew point of compressed air at an absolute pressure of 0.8MPa will also increase, which can meet the dehumidification requirements after the relative humidity increases. If the dry bulb temperature decreases by -20℃, it is necessary to reselect a higher absolute pressure of compressed air based on the relationship curve between the pressure dew point and the atmospheric pressure dew point.

[0074] The low-temperature air dehumidification device should maintain a sufficient distance between the air intake and the return air outlet of the environmental chamber to avoid the problem of air flow short circuit, that is, the low-temperature air inlet and the high-temperature air outlet should be kept at a sufficient distance, for example, 7m, 8m, 9m, etc. The length of a typical vehicle environmental chamber is 12 meters, and there is sufficient space to provide this distance. A typical vehicle test room should have a head-on fan. At this time, the air intake should be placed above the air flow direction of the return air outlet, that is, the low-temperature air inlet is located above the high-temperature air outlet.

[0075] Anything not described in this application can be achieved by adopting or drawing on existing technologies.

[0076] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0077] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A low-temperature air dehumidification device for vehicle low-temperature simulation test, characterized in that: The invention comprises an air compressor (1) and a heat exchanger (2), wherein the air compressor (1) has an air inlet and an air outlet, and the heat exchanger (2) has a low-temperature air inlet and a low-temperature air outlet, wherein the low-temperature air outlet is connected to the air inlet so that air can enter the air compressor (1) through the heat exchanger (2) under the action of the air compressor (1), and the heat exchanger (2) also has a high-temperature air inlet and a high-temperature air outlet, wherein the high-temperature air inlet is connected to the air outlet so that air can enter the heat exchanger (2) after being compressed and heated by the air compressor (1).

2. A low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 1, characterized in that: The high-temperature air outlet is connected to a pressure-maintaining valve (3).

3. A low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 2, characterized in that: A three-way pipeline is provided between the air compressor (1) and the heat exchanger (2), the three-way pipeline having an air inlet end and two air outlet ends, the air inlet end being connected to the air outlet, one of the air outlet ends being connected to the high-temperature air inlet, and the other air outlet end being connected to a thermal expansion valve (4), the temperature sensing package (41) of the thermal expansion valve (4) being provided at the high-temperature air outlet.

4. A low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 3, characterized in that: The pressure-maintaining valve (3) is connected to the high-temperature air outlet via an air outlet pipeline, and the temperature-sensing package (41) of the thermal expansion valve (4) is arranged on the air outlet pipeline.

5. The low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 1, characterized in that: The heat exchanger (2) comprises a shell (21) and a heat exchange tube (22) arranged in the shell (21); two ports of the heat exchange tube (22) are respectively the low-temperature air inlet and the low-temperature air outlet; the high-temperature air inlet and the high-temperature air outlet are respectively arranged at two opposite ends of the shell (21).

6. A low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 5, characterized in that: The housing (21) has a liquid discharge port, and a liquid discharge valve (211) is provided at the liquid discharge port.

7. A low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 6, characterized in that: The housing (21) has a liquid collecting portion which is recessed downwards, and the liquid discharge port is arranged in the liquid collecting portion.

8. A low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 7, characterized in that: The bottom wall of the shell (21) is arranged to be inclined downward along the direction from the high-temperature air inlet to the high-temperature air outlet, and the liquid collecting portion is arranged at one end of the shell (21) close to the high-temperature air outlet.

9. The low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 6, characterized in that: The drain valve (211) is connected to a water collecting tank so that condensed water in the housing (21) enters the water collecting tank via the drain valve (211).

10. A low-temperature air dehumidification device for vehicle low-temperature simulation test according to claim 9, characterized in that: A one-way valve is provided at the top of the water collecting tank, so that when condensed water enters the water collecting tank, the air in the water collecting tank is discharged through the one-way valve.

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