A whole vehicle heat and humidity balance system using a vortex tube and a control method thereof

Abstract

The application discloses a whole vehicle heat and humidity balance system adopting a vortex tube and a control method thereof, introduces the vortex tube into a heat management system, heats air into a vehicle cabin through a reheater by using additional heating capacity of the vortex tube, fully utilizes the additional heating capacity of hot fluid at an outlet of the vortex tube on the basis of improving a system energy efficiency ratio, and to a certain extent, overcomes a problem of cold and heat offset in a dehumidification process. The system switches a refrigeration dehumidification mode and a heating defogging mode by adjusting opening and closing of a four-way reversing valve and an electromagnetic valve, solves problems of too large air humidity in the vehicle cabin in the refrigeration mode and fogging of a windshield in the heating mode, and guarantees thermal comfort in the vehicle cabin and safety in a driving process.

Description

Technical Field

[0001] This invention belongs to the field of transcritical CO2 thermal management system for energy vehicles, specifically relating to a vehicle thermal and humidity balance system using vortex tubes and its control method. Background Technology

[0002] To achieve carbon neutrality, the development and promotion of new energy vehicles has become a hot topic. The lack of engine waste heat means that new energy vehicles typically require PTC (Positive Temperature Coefficient) auxiliary heating at low temperatures, resulting in high energy consumption. Therefore, efficient and energy-saving heat pump air conditioning systems have become a better choice. Traditionally used HFCs (hydrofluorocarbons) refrigerants in new energy vehicles are facing phase-out due to their excessively high GWP (Global Warming Potential). Furthermore, HFCs refrigerants have insufficient heating capacity in low-temperature winter environments. CO2, as a natural working fluid, has excellent heating performance at low temperatures and offers advantages in both environmental protection and energy conservation, making it one of the mainstream refrigerant alternatives.

[0003] The relatively low refrigeration efficiency of transcritical CO2 cycles is one of the main factors hindering their application in new energy vehicles. A vortex tube is a throttling device that can recover the pressure energy of high-pressure fluids. Relying on the complex heat and mass transfer between internal bidirectional vortices, it separates the inlet gas into two streams of different temperatures. Using vortex tubes can increase the cycle's specific cooling capacity, improve the cycle's refrigeration efficiency ratio, and provide additional heating capacity, making it one of the feasible methods to improve the performance of transcritical CO2 cycles.

[0004] On the other hand, besides indoor air temperature, indoor air humidity is also a crucial factor affecting human comfort. When the temperature inside the vehicle is high and cooling is needed, the air cooled by the evaporator often has a high relative humidity, requiring dehumidification to ensure passenger thermal comfort. Additionally, when the ambient temperature is low, the windshield is prone to fogging, affecting driving visibility and creating safety hazards. Heating and defogging mode requires hot, dry air to be blown onto the windshield, with a dew point temperature lower than the inner surface temperature of the windshield. This promotes the evaporation of moisture on the windshield, ultimately achieving defogging. Furthermore, due to the inevitable heat-cooling and dehumidification process during cooling and reheating, ensuring sufficient cooling or heating capacity is also a consideration. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a vehicle thermal and humidity balance system and its control method using vortex tubes to solve the problems of temperature and humidity regulation and control of the air in the passenger compartment and windshield defogging in the prior art.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A vehicle thermal and humidity balance system employing a vortex tube includes: a vortex tube and a gas-liquid separator, a first four-way reversing valve and a second four-way reversing valve;

[0008] The hot fluid outlet of the vortex tube is connected to a reheater, and the outlet of the reheater and the outlet of the gas-liquid separator are both connected to the inlet of the compressor.

[0009] The compressor outlet is connected to port a of the first four-way reversing valve, port b of the first four-way reversing valve is connected to the second interface of the outdoor heat exchanger, port c is connected to the inlet of the gas-liquid separator, and port d is connected to the first interface of the indoor second heat exchanger.

[0010] The first port of the outdoor heat exchanger is connected to port a of the second four-way reversing valve, port b of the second four-way reversing valve is connected to the high-pressure inlet of the vortex tube, and port d is connected to the cold fluid outlet of the vortex tube.

[0011] The C port of the second four-way reversing valve is connected to the first interface of the first indoor heat exchanger, or to the second interface of the second indoor heat exchanger.

[0012] When port C of the second four-way reversing valve is connected to the first interface of the indoor first heat exchanger, the second interface of the indoor first heat exchanger and the second interface of the second heat exchanger are connected.

[0013] When the second four-way reversing valve is connected to the second port of the indoor second heat exchanger, the first port of the indoor first heat exchanger and port a of the second four-way reversing valve are connected, and the second port of the indoor first heat exchanger is connected to port b of the first four-way reversing valve.

[0014] The invention is further improved in that:

[0015] Preferably, a first adjustable valve is provided between the vortex tube and the reheater.

[0016] Preferably, a second solenoid valve is provided between port C of the second four-way reversing valve and the first interface of the indoor first heat exchanger; a third solenoid valve is provided between the second interface of the indoor first heat exchanger and the second interface of the second heat exchanger.

[0017] Preferably, a first solenoid valve is provided between port c of the second four-way reversing valve and the second interface of the indoor second heat exchanger, a fifth solenoid valve is provided between port a of the second four-way reversing valve and the first interface of the indoor first heat exchanger, and a fourth solenoid valve is provided between the second interface of the indoor first heat exchanger and port b of the first four-way reversing valve.

[0018] Preferably, the condensate from the first indoor heat exchanger and the condensate from the second indoor heat exchanger are sprayed towards the outdoor heat exchanger.

[0019] Preferably, the vehicle's thermal and humidity balance system is equipped with a thermometer, the reheater is equipped with a dry-bulb and wet-bulb thermometer, and both the first and second indoor heat exchangers are equipped with dry-bulb thermometers.

[0020] A control method for a vehicle thermal and humidity balance system based on the above-mentioned vortex tube, including a cooling and dehumidification mode and a heating mode.

[0021] When the temperature inside the carriage is higher than 25°C, the cooling and dehumidification mode is adopted. The air entering the carriage passes through the first indoor heat exchanger and the second indoor heat exchanger for low-temperature dehumidification, and then is heated to the target air supply temperature through the reheater. The air humidity is adjusted by adjusting the CO2 ratio at the cold fluid outlet of the vortex tube. The air temperature is adjusted by adjusting the compressor speed and the mass flow rate of high-temperature CO2 flowing through the reheater.

[0022] When the temperature inside the carriage is below 10℃, the heating mode is used. After the air entering the carriage passes through the first heat exchanger, it is divided into two branches, which are heated by the second heat exchanger and the reheater respectively. The mixture is then sent into the carriage. The outlet air temperature is adjusted by adjusting the compressor speed, the mass flow rate of high-temperature CO2 flowing through the reheater and the second heat exchanger.

[0023] Preferably, in the cooling and dehumidification mode, the CO2 ratio at the outlet of the vortex tube cold fluid is increased to reduce the outlet air humidity; the CO2 ratio at the outlet of the vortex tube cold fluid is decreased to increase the outlet air humidity.

[0024] In cooling / dehumidification or heating mode, the compressor speed is reduced, resulting in a lower outlet air temperature; conversely, the compressor speed is increased, resulting in a higher outlet air temperature.

[0025] Preferably, in heating mode, if the air temperature after passing through the indoor heat exchanger is higher than the air temperature after passing through the reheater, the proportion of air flowing to the indoor second heat exchanger is increased; if the air temperature after passing through the indoor heat exchanger is lower than the air temperature after passing through the reheater, the proportion of air flowing to the indoor second heat exchanger is decreased.

[0026] Preferably, when the windshield needs to be defogged, the heating defogging mode is selected, and part of the CO2 flowing out from the second four-way reversing valve flows through the first indoor heat exchanger. By adjusting the CO2 flow ratio between the first heat exchanger and the outdoor heat exchanger, the air humidity is adjusted.

[0027] Increase the CO2 flow rate of the first indoor heat exchanger to reduce the outlet air humidity; decrease the CO2 flow rate of the first indoor heat exchanger to increase the outlet air humidity.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention discloses a vehicle thermal and humidity balance system employing a vortex tube. By introducing the vortex tube into the thermal management system, this invention improves the system's energy efficiency ratio and fully utilizes the additional heat generated by the hot fluid at the vortex tube outlet, overcoming the problem of heat and cold canceling each other out during dehumidification. The system switches between cooling / dehumidification, heating, and heating / defogging modes by adjusting the four-way reversing valve and solenoid valve, solving the problems of excessive humidity in the passenger compartment during cooling mode and windshield fogging during heating mode. When the passenger compartment temperature is high, the cooling / dehumidification mode first dehumidifies the intake air at a low temperature, then uses the additional heat generated by the hot fluid at the vortex tube outlet to heat it to the target air supply temperature. When the passenger compartment temperature is low, the heating mode heats the intake air using the indoor heat exchanger and reheater. When the windshield fogs up, the heating / defogging mode adjusts the humidity of the outlet air, allowing the fog to be removed. This method ensures thermal comfort inside the vehicle and safety during driving. It solves problems such as imperfect dehumidification mode strategies, insufficient technical solutions, and high energy consumption in transcritical CO2 vehicle thermal management systems. It has become one of the feasible dehumidification solutions for vehicle thermal management systems and can achieve thermal and humidity balance of the whole vehicle. It has important academic significance and engineering practical value.

[0030] Furthermore, by setting a first adjustable valve, the CO2 ratio at the cold fluid outlet of the vortex tube can be adjusted, thereby adjusting the outlet air humidity.

[0031] Furthermore, by setting up solenoid valves and regulating valves, switching between different modes can be achieved.

[0032] Furthermore, the condensate obtained from cooling the air in the indoor heat exchanger is sprayed onto the outdoor heat exchanger to enhance heat exchange. This "sweating cooling" technology further improves the system's energy efficiency ratio.

[0033] The present invention also discloses a control method for a vehicle thermal and humidity balance system using a vortex tube. The control process and method of the system in the two modes of cooling dehumidification and heating defogging are respectively controlled by adjusting the compressor speed and regulating valve opening, compressor speed and flow ratio of the two evaporator branches to ensure the outlet air temperature and humidity, and to maximize the utilization of heat, so that the system can perform efficient defogging.

[0034] Furthermore, in different modes, the outlet air temperature and humidity are controlled by adjusting the compressor speed and the first regulating valve, as well as the ratio of the compressor speed to the CO2 mass flow rate of the indoor second heat exchanger and reheater. In the heating mode, the air volume ratio flowing through the indoor second heat exchanger and reheater is adjusted to maximize heat utilization and enable the system to perform efficient demisting. Attached Figure Description

[0035] Figure 1 This is a flowchart of a vehicle thermal and humidity balance system cooling and dehumidification mode using a vortex tube according to the present invention;

[0036] Figure 2 This is a flowchart of the heating and demisting mode of a vehicle thermal and humidity balance system using vortex tubes according to the present invention.

[0037] Figure 3 This is a control strategy diagram of a vehicle thermal and humidity balance system using vortex tubes according to the present invention.

[0038] The components are: 1. Compressor, 2. Indoor primary heat exchanger, 3. Indoor secondary heat exchanger, 4. Reheater, 5. Outdoor heat exchanger, 6. Vortex tube, 7. Gas-liquid separator, 8. First four-way reversing valve, 9. Second four-way reversing valve, 10. First adjustable valve, 11. First solenoid valve, 12. Second solenoid valve, 13. Third solenoid valve, 14. Fourth solenoid valve, 15. Fifth solenoid valve, 16. Wet and dry bulb thermometer, 17. Second dry bulb thermometer, 18. First dry bulb thermometer, 19. Indoor fan, 20. Outdoor fan. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings:

[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] See Figure 1 and Figure 2 The first aspect of the present invention provides a vehicle thermal and humidity balance system using a vortex tube, including a compressor 1, an indoor first heat exchanger 2, an indoor second heat exchanger 3, a reheater 4, an outdoor heat exchanger 5, a vortex tube 6, a gas-liquid separator 7, a four-way reversing valve, an adjustable valve, a solenoid valve, a wet and dry bulb thermometer, an indoor fan 19, and an outdoor fan 20.

[0042] The first indoor heat exchanger 2, the second indoor heat exchanger 3, and the reheater 4 are all in the HVAC (Heating, Ventilation and Air Conditioning) system. The HVAC system of new energy vehicles has multiple air outlets, which can blow air to different positions in the cabin to meet multiple needs such as windshield defogging and passenger face blowing. The indoor fan is placed at the air inlet of the HVAC module.

[0043] The vortex tube 6 of this invention is provided with a high-pressure inlet, a cold fluid outlet, and a hot fluid outlet; the first four-way reversing valve 8 is provided with four ports, namely port a, port b, port c, and port d; the second four-way reversing valve 9 is provided with four ports, namely port a, port b, port c, and port d; the compressor 1 is provided with an air inlet and an air outlet; the gas-liquid separator 7 is provided with an inlet and an outlet, and the reheater 4 is provided with an inlet and an outlet; the remaining outdoor heat exchanger 5, the indoor first heat exchanger 2, and the indoor second heat exchanger 3 each have two ports. Since the flow direction of the internal fluid will be adjusted according to different modes, the ports on the left side of the figure are uniformly designated as the first port, and the ports on the right side are uniformly designated as the second port.

[0044] The outlet of reheater 4 and the outlet of gas-liquid separator 7 are simultaneously connected to the inlet of compressor 1. The outlet of compressor 1 is connected to port a of the first four-way reversing valve 8. Port b of the first four-way reversing valve 8 is connected to the second interface of outdoor heat exchanger 5. Port c of the first four-way reversing valve 8 is connected to the inlet of gas-liquid separator 7. Port d of the first four-way air exchanger valve 8 is connected to the first interface of the second heat exchanger 3. The first interface of outdoor heat exchanger 5 is connected to port a of the second four-way reversing valve 9. Port b of the second four-way reversing valve 9 is connected to the high-pressure inlet of vortex tube 6. Port d of the second four-way reversing valve 9 is connected to the cold fluid outlet of vortex tube 6. The hot fluid outlet of vortex tube 6 is connected to the inlet of reheater 4.

[0045] The c port of the second four-way reversing valve 9 is connected to the inlet of the second solenoid valve 12 or the outlet of the first solenoid valve 11. The outlet of the second solenoid valve 12 is connected to the first interface of the indoor first heat exchanger 2. The inlet of the first solenoid valve 11 is connected to the second interface of the indoor second heat exchanger 3.

[0046] The first port of the indoor first heat exchanger 2 is connected to the outlet of the fifth solenoid valve 15 or the outlet of the second solenoid valve 12. The second port of the indoor first heat exchanger 2 is connected to the inlet of the third solenoid valve 13 or the inlet of the fourth solenoid valve 14. The outlet of the third solenoid valve 13 is connected to the second port of the indoor second heat exchanger 3. The outlet of the fourth solenoid valve 14 is connected to port b of the first four-way reversing valve 14.

[0047] The second port of the indoor second heat exchanger 3 is connected to the outlet of the third solenoid valve 13 or the inlet of the first solenoid valve 11, and the first port of the indoor second heat exchanger 3 is connected to the d port of the first four-way reversing valve 8.

[0048] The fourth solenoid valve 14 is connected to port b of the first four-way reversing valve 8 and the second port of the first indoor heat exchanger 2, respectively. The inlet of the fifth solenoid valve 15 is connected to port a of the second four-way reversing valve 9 and the first port of the first indoor heat exchanger 2, respectively.

[0049] Furthermore, in the HAVC system, a dry-bulb and wet-bulb thermometer 16 is arranged after the reheater, and a dry-bulb thermometer is arranged after the other heat exchangers. Specifically, a first dry-bulb thermometer 18 is installed after the first indoor heat exchanger 2, and a second dry-bulb thermometer 17 is installed after the second indoor heat exchanger 3.

[0050] Furthermore, the outdoor heat exchanger 5 is equipped with an outdoor fan 20 for supplying air to the outdoor heat exchanger 5. An indoor fan 19 is installed outside the indoor first heat exchanger 2 for supplying indoor air to the HVAC system.

[0051] Based on the above system composition, the present invention can provide a cooling and dehumidification mode and a heating and defogging mode. The connection between the devices is partially adjusted for different modes.

[0052] See Figure 1 A system flowchart for a cooling and dehumidification mode is provided. The system includes a compressor 1, an indoor first heat exchanger 2, an indoor second heat exchanger 3, a reheater 4, an outdoor heat exchanger 5, a vortex tube 6, a gas-liquid separator 7, a first four-way reversing valve 8, a second four-way reversing valve 9, a first adjustable valve 10, a first solenoid valve 11, a second solenoid valve 12, a third solenoid valve 13, a fourth solenoid valve 14, a fifth solenoid valve 15, a wet-bulb and dry-bulb thermometer 16, a dry-bulb thermometer 17, an indoor fan 19, and an outdoor fan 20.

[0053] When the cabin temperature exceeds 25°C and passengers select cooling mode, the transcritical CO2 heat pump air conditioning system switches to cooling mode. After the incoming air flows through the evaporator and is cooled, the relative humidity increases, exceeding the suitable humidity range, thus requiring dehumidification. At this time, the fogging on the windshield is located on the outer side of the glass; therefore, windshield defogging is not considered within the scope of this system.

[0054] The system switches modes by adjusting the connection of the first four-way reversing valve 8 and the second four-way reversing valve 9, as well as the on / off states of the first solenoid valve 11, the second solenoid valve 12, the third solenoid valve 13, the fourth solenoid valve 14, and the fifth solenoid valve 15. The specific working method of the cooling and dehumidification mode is as follows:

[0055] The first four-way reversing valve 8 has ports a and b connected, and ports c and d connected. The second four-way reversing valve 9 has ports a and b connected, and ports c and d connected. The second solenoid valve 12 and the third solenoid valve 13 are in the open state, while the first solenoid valve 11, the fourth solenoid valve 14, and the fifth solenoid valve 15 are in the closed state. The high-temperature and high-pressure CO2 compressed by the compressor 1 flows to port a of the first four-way reversing valve 8, and flows into the outdoor heat exchanger 5 from port b. After being cooled in the outdoor heat exchanger 5, the CO2 flows to port a of the second four-way reversing valve 9, and flows into the high-pressure inlet of the vortex tube 6 from port b. The CO2 from the cold fluid outlet flows to port d of the second four-way reversing valve 9, and flows out from port c. After passing through the second solenoid valve 12, it flows sequentially through the indoor first heat exchanger 2, the third solenoid valve 13, and the indoor second heat exchanger 3. After the indoor air intake cooling is completed, the CO2 flows to port d of the first four-way reversing valve 8, and flows into the gas-liquid separator 7 from port c. The CO2 from the hot fluid outlet of the vortex tube 6 flows through the first adjustable valve 10. After the reheater 4 completes the heat release, it merges with the CO2 from the outlet of the gas-liquid separator 7 and flows back to the suction port of the compressor 1. The air entering the carriage passes through the first indoor heat exchanger 2 and the second indoor heat exchanger 3 in sequence for low-temperature dehumidification. The temperature is reduced to below the suitable air supply temperature to reduce the moisture content. Then it is blown to the reheater 4 to be heated to the suitable air supply temperature and blown into the carriage through the air outlet to regulate the indoor temperature and humidity.

[0056] The speed of compressor 1 and the opening degree of the first adjustable valve 10 can be adjusted according to the outlet air temperature and humidity to meet the outlet air requirements. The set temperature and humidity target values ​​can be set by the automobile manufacturer based on experience or set and changed by the occupants themselves. The outlet air humidity and temperature are measured by wet-bulb and dry-bulb thermometers 16, and the saturated air temperature after flowing through the evaporator is measured by dry-bulb thermometer 17.

[0057] In dehumidification mode, to improve system efficiency, a "sweating cooling" technology is adopted. The water condensed after the two indoor heat exchangers absorb heat is sprayed onto the outdoor heat exchanger 5 to enhance heat exchange and improve the energy efficiency ratio. The water spraying rate is controlled within a certain range to improve the utilization efficiency of the sprayed water and maximize the system energy efficiency ratio.

[0058] During operation, the outlet humidity of the HVAC system is controlled according to the opening degree of the first adjustable valve 10. When the outlet humidity is higher than the set value, the opening degree of the first adjustable valve 10 is reduced, the proportion of CO2 at the outlet of the cold fluid of the vortex tube 6 is increased, the mass flow rate of low-temperature CO2 flowing through the first heat exchanger 2 and the second heat exchanger 3 in the room increases, the dehumidification capacity increases, and the outlet humidity is reduced. When the outlet humidity is lower than the set value, the opening degree of the first adjustable valve 10 is increased, the proportion of CO2 at the outlet of the cold fluid of the vortex tube 6 is reduced, the mass flow rate of low-temperature CO2 flowing through the first heat exchanger 2 and the second heat exchanger 3 in the room decreases, the dehumidification capacity decreases, and the outlet humidity is increased. Under other circumstances, the opening degree of the first adjustable valve 10 remains unchanged.

[0059] During operation, the outlet air temperature of the HVAC system is controlled according to the compressor speed. When the outlet air temperature is higher than the set value, the speed of compressor 1 is reduced, the mass flow rate of high-temperature CO2 flowing through reheater 4 is reduced, and the outlet air temperature is lowered. When the outlet air temperature is lower than the set value, the speed of compressor 1 is increased, the mass flow rate of high-temperature CO2 flowing through reheater is increased, and the outlet air temperature is increased. Under other conditions, the speed of compressor 1 remains unchanged.

[0060] Please see Figure 2 As shown, the present invention provides a system flowchart of a heating and demisting mode. The system includes a compressor 1, an indoor first heat exchanger 2, an indoor second heat exchanger 3, a reheater 4, an outdoor heat exchanger 5, a vortex tube 6, a gas-liquid separator 7, a first four-way reversing valve 8, a second four-way reversing valve 9, a first adjustable valve 10, a first solenoid valve 11, a second solenoid valve 12, a third solenoid valve 13, a fourth solenoid valve 14, a fifth solenoid valve 15, a wet-bulb thermometer 16, a dry-bulb thermometer 17, a dry-bulb thermometer 18, an indoor fan 19, and an outdoor fan 20.

[0061] When the cabin temperature is below 10℃, passengers can select the heating mode and manually choose whether to activate the windshield defroster mode based on whether the windshield is fogged up. The cabin needs heating to reach a comfortable temperature. Simultaneously, because the inner surface temperature of the windshield is low, air from inside the cabin or exhaled breath blowing onto the windshield can easily cause fogging, affecting driving safety. Therefore, warm air with lower humidity is needed to blow onto the windshield to defog and heat the cabin.

[0062] The system switches modes by adjusting the connection mode of the first four-way reversing valve 8 and the second four-way reversing valve 9, as well as the opening and closing of the first solenoid valve 11, the second solenoid valve 12, the third solenoid valve 13, the fourth solenoid valve 14 and the fifth solenoid valve 15.

[0063] The heating and defogging mode usually needs to be manually activated. When the defogging mode is not activated and only the regular heating mode is needed, the working process is as follows:

[0064] The first four-way reversing valve 8 has ports a and d connected, and ports b and c connected. The second four-way reversing valve 9 has ports a and d connected, and ports b and c connected. The first solenoid valve 11 is in the open state, and the fourth solenoid valve 14, the fifth solenoid valve 15, the second solenoid valve 12, and the third solenoid valve 13 are in the closed state. The first regulating valve 10 is fully open. The high-temperature and high-pressure CO2 compressed by the compressor 1 flows to port a of the first four-way reversing valve 8 and flows into the indoor second heat exchanger 3 from port d. The cooled CO2 flows through the first solenoid valve 11 to port c of the second four-way reversing valve 8 and flows into the high-pressure inlet of the vortex tube 7 from port b. The CO2 from the cold fluid outlet flows to port d of the second four-way reversing valve 9 and flows out from port a to the outdoor heat exchanger 5. The CO2 after heat absorption flows to port b of the first four-way reversing valve 8 and flows into the gas-liquid separator 7 from port c. The CO2 from the hot fluid outlet of the vortex tube 6 flows through the first adjustable valve 10 and the reheater 4 to release heat, and then merges with the CO2 from the outlet of the gas-liquid separator 7, flowing back together to the suction port of the compressor 1.

[0065] During operation, the outlet air temperature of the HVAC system is controlled according to the speed of compressor 1. When the outlet air temperature is higher than the set value, the speed of compressor 1 is reduced, the mass flow rate of high-temperature CO2 flowing through reheater 4 and indoor second heat exchanger 3 is reduced, and the outlet air temperature is lowered. When the outlet air temperature is lower than the set value, the speed of compressor 1 is increased, the mass flow rate of high-temperature CO2 flowing through reheater 4 and indoor second heat exchanger 3 is increased, and the outlet air temperature is increased. Under other conditions, the speed of compressor 1 remains unchanged.

[0066] Furthermore, the airflow ratio between the two ducts blowing towards the indoor second heat exchanger 3 and reheater 4 is adjusted based on the temperature difference of the air flowing through the two heat exchangers. If the air temperature after flowing through the indoor second heat exchanger 3 is higher than the air temperature after flowing through the reheater, the proportion of air flowing towards the indoor second heat exchanger 3 is increased; if the air temperature after flowing through the indoor second heat exchanger 3 is lower than the air temperature after flowing through the reheater, the proportion of air flowing towards the indoor second heat exchanger 3 is decreased; otherwise, the airflow ratio between the two ducts remains unchanged.

[0067] Furthermore, in heating mode, the humidity of the air outlet is lower than the humidity suitable for the human body. In order to ensure the thermal comfort of passengers, humidification is required in the carriage, which is achieved with the assistance of a humidifier.

[0068] Furthermore, after passing through the first indoor heat exchanger 2, the HVAC air intake is split into two parallel streams and blown towards the second indoor heat exchanger 3 and reheater 4 for heating. The mixed hot air is then blown into the interior of the vehicle through a damper to regulate the indoor temperature, with the windshield duct closed. During this process, since no CO2 refrigerant flows through the first indoor heat exchanger 2, it is inactive.

[0069] When the windshield fogs up, manually turn on the windshield defroster mode. The specific working method for the heating defroster mode is as follows:

[0070] The first four-way reversing valve 8 has ports a and d connected, and ports b and c connected. The second four-way reversing valve 9 has ports a and d connected, and ports b and c connected. The first solenoid valve 11, the fourth solenoid valve 14, and the fifth solenoid valve 15 are in the open state, while the second solenoid valve 12 and the third solenoid valve 13 are in the closed state. The first regulating valve 10 is fully open. The high-temperature and high-pressure CO2 compressed by the compressor 1 flows to port a of the first four-way reversing valve 8 and flows into the second heat exchanger 3 in the room from port d. The cooled CO2 flows through the first solenoid valve 11 to port c of the second four-way reversing valve 8 and flows into the second heat exchanger 3 in the room from port b. The CO2 flowing into the high-pressure inlet of the vortex tube 7 flows to the d port of the second four-way reversing valve 9. After flowing out from the a port, it splits into two paths: one flows to the outdoor heat exchanger 5, and the other flows through the fifth solenoid valve 15 to the indoor first heat exchanger 2, and then through the fourth solenoid valve 14. After the two CO2 paths have completed heat absorption, they merge and flow together to the b port of the first four-way reversing valve 8. From the c port, it flows into the gas-liquid separator 7. The CO2 from the hot fluid outlet flows through the first adjustable valve 10 and the reheater 4 to complete heat release, and then merges with the CO2 from the outlet of the gas-liquid separator 7. Together, they flow back to the suction port of the compressor 1.

[0071] Furthermore, after the air entering the carriage is dehumidified at low temperature by the first indoor heat exchanger 2, it is then split into two parallel paths and blown into the second indoor heat exchanger 3 and reheater 4 for heating. Part of the mixed air is blown directly to the windshield through the air outlet to heat and defog it, while part of it is blown into the interior of the carriage through other air outlets to regulate the indoor temperature.

[0072] During operation, the outlet air humidity of the HVAC system is controlled based on the CO2 flow ratio of the two evaporator branches of the indoor first heat exchanger 2 and the outdoor heat exchanger 5. When the outlet air humidity is higher than the set value, the CO2 flow rate of the indoor first heat exchanger 2 branch is increased, which increases the heat exchange between the indoor first heat exchanger 2 and the incoming air, increases the dehumidification capacity, and reduces the outlet air humidity. When the outlet air humidity is lower than the set value, the CO2 flow rate of the indoor first heat exchanger branch is decreased, which decreases the heat exchange between the indoor first heat exchanger 2 and the incoming air, decreases the dehumidification capacity, and increases the outlet air humidity. Under other conditions, the CO2 flow ratio of the two evaporator branches of the indoor first heat exchanger 2 and the outdoor heat exchanger remains unchanged.

[0073] Furthermore, in the heating and defogging mode, in order to effectively defog the windshield, the air humidity is relatively low, and humidification is required in the cabin to ensure the thermal comfort of passengers, which is achieved with the assistance of a humidifier.

[0074] Furthermore, the compressor speed 1 and the CO2 flow ratio of the two evaporator branches of the indoor first heat exchanger 2 and the outdoor heat exchanger 5 can be adjusted according to the outlet air temperature and humidity to meet the outlet air requirements. The set temperature and humidity target values ​​can be set by the car manufacturer based on experience or set and changed by the passengers themselves. The outlet air humidity and temperature are measured by wet-bulb and dry-bulb thermometers 16 and 17, respectively, and the saturated air temperature after flowing through the evaporator is measured by a dry-bulb thermometer 18.

[0075] Please see Figure 3 As shown, based on the above-mentioned device, the present invention also provides a method for coordinated control of outlet air temperature and humidity in different system modes, the specific control process of which is as follows:

[0076] When the temperature inside the carriage exceeds 25°C, passengers can select the cooling and dehumidification mode. During operation, the dehumidification process will be adjusted based on the humidity of the air outlet. and set the air outlet humidity Deviation between Change the opening degree of the first adjustable valve 10, when Decreasing the opening of the first adjustable valve 10 increases the proportion of CO2 at the cold fluid outlet of the vortex tube 6, increasing the mass flow rate of low-temperature CO2 flowing through the first indoor heat exchanger 2 and the second indoor heat exchanger 3, increasing the heat exchange of the incoming air, increasing the dehumidification capacity, and lowering the air temperature measured by the dry-bulb thermometer 17, further reducing the outlet air humidity; when Increasing the opening of the first regulating valve 10 reduces the proportion of CO2 at the cold fluid outlet of the vortex tube 6, thereby reducing the mass flow rate of low-temperature CO2 flowing through the first indoor heat exchanger 2 and the second indoor heat exchanger 3, reducing the heat exchange of the incoming air, reducing the dehumidification capacity, and causing the air temperature measured by the dry bulb thermometer 17 to rise, further increasing the outlet air humidity; under other conditions, the opening of the first adjustable valve 10 remains unchanged.

[0077] During the cooling and dehumidification mode operation, the air outlet temperature t is adjusted accordingly. exit and set air outlet temperature t set The deviation Δt between exit By changing the speed of compressor 1 and the opening degree of the first adjustable valve 10, when Δt exit >1℃, reducing the speed of compressor 1 decreases the mass flow rate of high-temperature CO2 through reheater 4, reducing the air temperature rise and further reducing the outlet air temperature; when Δt exit When the temperature is below -1℃, increasing the speed of compressor 1 increases the mass flow rate of high-temperature CO2 through reheater 4, thereby increasing the air temperature rise and further increasing the outlet air temperature; under other conditions, the speed of compressor 1 remains unchanged.

[0078] When the cabin temperature is below 10℃, passengers select the heating mode. If the windshield fogs up, the windshield defrost function will be activated. This is the heating and defrosting mode. During operation, the system adjusts according to the air humidity. and set the air outlet humidity Deviation between By changing the CO2 flow ratio of the two evaporator branches of the indoor first heat exchanger 2 and the outdoor heat exchanger 5, when Increasing the CO2 flow rate in the second branch of the indoor first heat exchanger increases the heat exchange between the indoor first heat exchanger 2 and the incoming air, thus increasing the dehumidification capacity. The dry-bulb thermometer 18 measures a decrease in the saturated air temperature after passing through the indoor first heat exchanger 1, further reducing the outlet air humidity. Reducing the CO2 flow rate of the indoor first heat exchanger 2 branch reduces the heat exchange between the indoor first heat exchanger 2 and the incoming air, reduces the dehumidification capacity, and increases the temperature of the saturated air after passing through the indoor first heat exchanger 1 as measured by the dry bulb thermometer 18, further increasing the outlet air humidity; under other conditions, the CO2 flow rate ratio of the two evaporator branches of the indoor first heat exchanger 2 and the outdoor heat exchanger 5 remains unchanged.

[0079] During operation in heating and demisting mode, the temperature is adjusted according to the outlet air temperature t. exit and set air outlet temperature t set The deviation Δt between exit Change the speed of compressor 1, when Δt exit >1℃, reducing the speed of compressor 1 decreases the mass flow rate of high-temperature CO2 through the indoor second heat exchanger 3 and reheater 4, reducing the air temperature rise and further reducing the outlet air temperature; when Δt exit When the temperature is below -1℃, increasing the speed of compressor 1 increases the mass flow rate of high-temperature CO2 flowing through the inner second heat exchanger 3 and reheater 4, thereby increasing the air temperature rise and further increasing the outlet air temperature; under other conditions, the speed of compressor 1 remains unchanged.

[0080] During the heating and demisting mode operation, the outlet air temperature t after flowing through the second heat exchanger 3 in the room is used as the reference. exit1 and the outlet air temperature t after passing through reheater 4 exit2 The deviation Δt between d Change the airflow ratio between the two ducts blowing towards the second heat exchanger 3 and the reheater 4 in the room, t exit1 t was measured by dry bulb thermometer 17 exit2 Measured by wet-bulb and dry-bulb thermometer 16; when Δt d If the temperature is >1℃, the proportion of air flowing into the duct leading to the second indoor heat exchanger 3 will be increased, reducing the air temperature rise after passing through the second indoor heat exchanger 3 and increasing the air temperature rise after passing through the reheater 4, thus achieving a consistent outlet air temperature and maximizing heat utilization; when Δt dWhen the temperature is below -1℃, the proportion of air flowing to the second indoor heat exchanger 3 is reduced; the temperature rise of the air after flowing through the second indoor heat exchanger 3 is increased and the temperature rise of the air after flowing through the reheater 4 is reduced, so as to achieve a consistent outlet temperature, reasonable matching of air volume and heat exchange, and maximum utilization of heat; under other conditions, the air volume ratio of the two air ducts remains unchanged.

[0081] During the operation of the heating and defogging mode, the air humidity inside the carriage is monitored in real time. According to air humidity and suitable humidity Deviation between Adjust the humidifier's operating setting when Reduce the operating level of the in-vehicle humidifier to lower the humidity in the cabin and improve thermal comfort; when Increase the operating level of the in-vehicle humidifier to improve the humidity in the cabin and meet thermal comfort requirements; under other conditions, the operating level of the in-vehicle humidifier remains unchanged.

[0082] When passengers do not turn on the defogging mode in heating mode, the fourth solenoid valve 14 and the fifth solenoid valve 15 are closed. At this time, the HVAC air outlet does not need to be controlled for relative humidity, and the other control strategies and methods remain unchanged.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vehicle thermal and humidity balance system employing vortex tubes, characterized in that, include: Vortex tube (6) and gas-liquid separator (7), first four-way reversing valve (8) and second four-way reversing valve (9); The hot fluid outlet of the vortex tube (6) is connected to the reheater (4), and the outlet of the reheater (4) and the outlet of the gas-liquid separator (7) are both connected to the inlet of the compressor (1). The outlet of the compressor (1) is connected to port a of the first four-way reversing valve (8), port b of the first four-way reversing valve (8) is connected to the second interface of the outdoor heat exchanger (5), port c is connected to the inlet of the gas-liquid separator (7), and port d is connected to the first interface of the indoor second heat exchanger (3). The first port of the outdoor heat exchanger (5) is connected to the a port of the second four-way reversing valve (9), the b port of the second four-way reversing valve (9) is connected to the high pressure inlet of the vortex tube (6), and the d port is connected to the cold fluid outlet of the vortex tube (6). The c port of the second four-way reversing valve (9) is connected to the first interface of the first indoor heat exchanger (2), or to the second interface of the second indoor heat exchanger (3); When port c of the second four-way reversing valve (9) is connected to the first interface of the indoor first heat exchanger (2), the second interface of the indoor first heat exchanger (2) and the second interface of the second heat exchanger (3) are connected. When the second four-way reversing valve (9) and the second port of the indoor second heat exchanger (3) are connected, the first port of the indoor first heat exchanger (2) and the a port of the second four-way reversing valve (9) are connected, and the second port of the indoor first heat exchanger (2) and the b port of the first four-way reversing valve (8) are connected.

2. The vehicle thermal and humidity balance system using vortex tubes according to claim 1, characterized in that, A first adjustable valve (10) is provided between the vortex tube (6) and the reheater (4).

3. A vehicle thermal and humidity balance system using vortex tubes according to claim 1, characterized in that, A second solenoid valve (12) is provided between port c of the second four-way reversing valve (9) and the first port of the indoor first heat exchanger (2); a third solenoid valve (13) is provided between the second port of the indoor first heat exchanger (2) and the second port of the second heat exchanger (3).

4. A vehicle thermal and humidity balance system using vortex tubes according to claim 1, characterized in that, A first solenoid valve (11) is provided between port c of the second four-way reversing valve (9) and the second port of the indoor second heat exchanger (3). A fifth solenoid valve (15) is provided between port a of the second four-way reversing valve (9) and the first port of the indoor first heat exchanger (2). A fourth solenoid valve (14) is provided between the second port of the indoor first heat exchanger (2) and port b of the first four-way reversing valve (8).

5. A vehicle thermal and humidity balance system employing a vortex tube according to claim 1, characterized in that, The condensate from the first indoor heat exchanger (2) and the second indoor heat exchanger (3) is sprayed onto the outdoor heat exchanger (5).

6. A vehicle thermal and humidity balance system employing a vortex tube according to claim 1, characterized in that, The vehicle's thermal and humidity balance system is equipped with a thermometer, the reheater (4) is equipped with a dry and wet bulb thermometer, and the first indoor heat exchanger (2) and the second indoor heat exchanger (3) are both equipped with dry bulb thermometers.

7. A control method for a vehicle thermal and humidity balance system using a vortex tube as described in claim 1, characterized in that, Includes cooling / dehumidification mode and heating mode; When the temperature inside the carriage is higher than 25°C, the cooling and dehumidification mode is adopted. The air entering the carriage passes through the first indoor heat exchanger (2) and the second indoor heat exchanger (3) in sequence for low-temperature dehumidification, and then is heated to the target air supply temperature through the reheater (4). The air humidity is adjusted by adjusting the CO2 ratio at the cold fluid outlet of the vortex tube (6). The air temperature is adjusted by adjusting the speed of the compressor (1) and the mass flow rate of high-temperature CO2 flowing through the reheater (4). When the temperature of the carriage is below 10℃, the heating mode is adopted. After the air in the carriage passes through the first heat exchanger (2) in the room, it is divided into two branches and heated by the second heat exchanger (3) and the reheater (4) respectively. The mixture is then sent into the carriage. By adjusting the speed of the compressor (1), the mass flow rate of high temperature CO2 flowing through the reheater (4) and the second heat exchanger (3) in the room is adjusted, and the outlet air temperature is adjusted.

8. The control method according to claim 7, characterized in that, In cooling and dehumidification mode, increase the CO2 ratio at the cold fluid outlet of the vortex tube (6) to reduce the outlet air humidity; decrease the CO2 ratio at the cold fluid outlet of the vortex tube (6) to increase the outlet air humidity. In cooling / dehumidification mode or heating mode, reduce the speed of compressor (1) to reduce the outlet air temperature, or increase the speed of compressor (1) to increase the outlet air temperature.

9. The control method according to claim 7, characterized in that, In heating mode, if the air temperature after passing through the indoor heat exchanger (3) is higher than the air temperature after passing through the reheater (4), the proportion of air flowing to the indoor second heat exchanger (3) is increased; if the air temperature after passing through the indoor heat exchanger (3) is lower than the air temperature after passing through the reheater (4), the proportion of air flowing to the indoor second heat exchanger (3) is decreased.

10. The control method according to claim 7, characterized in that, When the windshield needs to be defogged, select the heating defogging mode. Part of the CO2 flowing out from the second four-way reversing valve (9) flows through the first indoor heat exchanger (2). By adjusting the CO2 flow ratio between the first heat exchanger (2) and the outdoor heat exchanger (5), the air humidity is adjusted. Increase the CO2 flow rate of the first indoor heat exchanger (2) to reduce the outlet air humidity; decrease the CO2 flow rate of the first indoor heat exchanger (2) to increase the outlet air humidity.

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