Vehicle-mounted air conditioning unit

Abstract

The utility model provides a vehicle-mounted air conditioning unit, which comprises an outdoor refrigerating system and at least one group of indoor heat exchange system which are connected with each other and realize heat exchange, and refrigerating and refrigerating media with different properties circularly flow in the outdoor refrigerating system and the indoor heat exchange system respectively. According to the vehicle-mounted air conditioning unit, the indoor refrigerating system and the indoor heat exchange system are arranged to control the temperature in a vehicle, refrigerants do not enter a room, and potential safety hazards caused by leakage of the refrigerants are avoided.

Description

Technical Field

[0001] This utility model belongs to the field of rail vehicle technology, and in particular to an on-board air conditioning unit. Background Technology

[0002] Rail vehicle air conditioning systems are specifically designed for rail transit vehicles such as trains, subways, light rail, and trams. They not only provide passengers with a comfortable riding environment but also ensure stable air quality and temperature inside the vehicle. Currently, most rail vehicle air conditioning units are unit-type units, integrating components such as the compressor, condenser, condenser fan, evaporator, and ventilation fan into a single housing. They are mainly divided into an outdoor cavity and an indoor cavity. The outdoor cavity is open to the atmosphere and uses the condenser fan for forced convection heat exchange with the condenser. The indoor cavity is open to the interior of the vehicle and uses the ventilation fan for forced convection heat exchange with the evaporator, thereby controlling the interior temperature. Therefore, the evaporator of the air conditioning unit is actually located inside the vehicle. If the evaporator leaks, refrigerant will leak into the vehicle, posing a safety hazard.

[0003] In view of this, this utility model is proposed. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a vehicle air conditioning unit that controls the temperature inside the vehicle by setting up two systems: an indoor cooling system and an indoor heat exchange system, so that the refrigerant does not enter the room and there will be no safety hazards caused by refrigerant leakage.

[0005] To achieve the above objectives, this utility model provides a vehicle-mounted air conditioning unit, the technical solution of which is:

[0006] A vehicle-mounted air conditioning unit includes an outdoor refrigeration system installed outside the vehicle compartment and at least one indoor heat exchange system installed inside the vehicle compartment. Different types of refrigerants and heat exchangers circulate in the outdoor refrigeration system and the indoor heat exchange system, respectively. The heat exchanger circulation pipeline of the indoor heat exchange system extends outside the vehicle compartment and is connected to the outdoor refrigeration system for heat exchange.

[0007] Furthermore, the outdoor cooling system includes a first heat exchanger, and the circulation pipeline is connected to the first heat exchanger to achieve heat exchange.

[0008] Furthermore, the air conditioning unit is a split type, including an outdoor refrigeration system and a corresponding set of indoor heat exchange systems; or the air conditioning unit is a unit type, including an outdoor refrigeration system and multiple sets of indoor heat exchange systems connected in parallel.

[0009] Furthermore, the indoor heat exchange system includes one or more indoor heat exchange units connected in parallel.

[0010] Furthermore, the circulation pipeline is covered with thermal insulation material.

[0011] Furthermore, a heat tracing system is installed on the circulation pipeline.

[0012] Furthermore, the indoor heat exchange system includes an expansion tank that can balance pressure fluctuations in the pipeline.

[0013] Furthermore, the expansion tank includes an expander disposed within the tank body, the expander being filled with compressed air or nitrogen to buffer and stabilize pressure.

[0014] Furthermore, the expansion tank also includes a safety valve for adjusting the pressure inside the expansion tank.

[0015] Furthermore, the outdoor refrigeration system includes a detector for detecting refrigerant leaks.

[0016] After adopting the above technical solution, the vehicle air conditioning unit provided by this utility model has the following advantages compared with the prior art:

[0017] 1. By eliminating the indoor evaporator and using an indoor heat exchange system with circulating refrigerant to isolate the refrigerant of the air conditioning unit from the car, the possibility of refrigerant remaining in the car is completely eliminated, thus improving the safety of rail vehicle operation.

[0018] 2. By isolating the outdoor refrigeration system, the refrigerant is kept only in the outdoor unit, preventing evaporator leaks from leaking refrigerant into the vehicle. This not only avoids safety hazards inside the vehicle but also improves its widespread application.

[0019] 3. The refrigerant detector continuously monitors for refrigerant leaks. When a refrigerant leak is detected, the outdoor fan will be activated to quickly disperse the refrigerant into the outdoor atmosphere, rapidly reducing the refrigerant concentration to a flammable level and preventing potential safety hazards outside the vehicle.

[0020] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0021] The accompanying drawings, as part of this utility model, are used to provide a further understanding of the present utility model. The illustrative embodiments and descriptions of the present utility model are used to explain the present utility model, but do not constitute an undue limitation of the present utility model. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0022] In the attached diagram:

[0023] Figure 1This utility model provides a schematic diagram of a unit-type structure in a vehicle-mounted air conditioning unit;

[0024] Figure 2 This utility model provides a schematic diagram of a split-type structure in a vehicle-mounted air conditioning unit;

[0025] The components include: 1. Compressor; 2. Four-way reversing valve; 21. First valve port of the four-way valve; 22. Second valve port of the four-way valve; 23. Third valve port of the four-way valve; 24. Fourth valve port of the four-way valve; 3. First heat exchanger; 4. Expansion tank; 5. Liquid supply pump; 6. Electronic expansion valve; 7. Outdoor fan; 8. Second heat exchanger; 9. Refrigerant sensor; 10. Indoor temperature sensor; 11. Indoor heat exchange unit; 12. Indoor fan.

[0026] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0028] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] Current rail vehicle air conditioning units typically include a compressor, condenser, condenser fan, evaporator, and fan, and can be divided into an outdoor cavity and an indoor cavity. The outdoor cavity is open to the outside atmosphere, and the condenser exchanges heat with the condenser using forced convection from the condenser fan. The indoor cavity is open to the interior of the vehicle, and the evaporator exchanges heat with the vehicle using forced convection from the fan, thereby controlling the interior temperature. Therefore, the evaporator of the air conditioning unit is actually located inside the vehicle. If the evaporator leaks, refrigerant will leak into the vehicle, posing a safety hazard to the interior of the rail vehicle. To address the aforementioned problems, the following technical solution is proposed.

[0031] This utility model provides a vehicle-mounted air conditioning unit, including an outdoor refrigeration system installed outside the vehicle compartment and at least one indoor heat exchange system installed inside the vehicle compartment. Different types of refrigerants and coolants circulate in the outdoor refrigeration system and the indoor heat exchange system, respectively. The coolant circulation pipeline of the indoor heat exchange system extends outside the vehicle compartment and connects to the outdoor refrigeration system for heat exchange.

[0032] like Figure 1 and Figure 2 As shown, this embodiment provides a vehicle-mounted air conditioning unit, including an outdoor refrigeration system installed on the roof or underside of the rail vehicle, i.e., outside the vehicle body. It includes a compressor 1 that drives the refrigerant flow, a four-way reversing valve 2 that regulates the refrigerant flow direction, a first heat exchanger 3, and a second heat exchanger 8. By adjusting the flow direction of the four-way reversing valve 2, the operating state of the first heat exchanger 3 and the second heat exchanger 8 is controlled, i.e., the cooling or heating state, to achieve the cooling or heating mode of the air conditioning unit.

[0033] The indoor heat exchange system is installed inside the carriage to regulate the air temperature inside the carriage. It includes a liquid water pump 5 that drives the refrigerant circulation, an indoor heat exchange unit for heat exchange between the refrigerant and the indoor air, and circulation pipes. The liquid water pump 5 drives the refrigerant to flow in the circulation pipes, which are connected to the outdoor refrigeration system. The refrigerant takes heat at the connection point and carries the heat to the indoor heat exchange unit through circulation, so that the indoor heat exchange unit can exchange heat with the indoor air.

[0034] In this embodiment, the circulation pipe extends out of the vehicle compartment to the outdoor refrigeration system, connecting to the first heat exchanger 3 and extracting heat. In this embodiment, the connection can be any method such as covering, contacting, close proximity, insertion, or bonding. For example, the circulation pipe can form a continuous U-shaped or other arbitrary-shaped coil at the first heat exchanger 3, covering the back of the first heat exchanger 3 for radiative heat exchange. Alternatively, the first heat exchanger 3 can be a finned heat exchanger with double holes on the fins; one hole leads to the refrigerant pipe, and the other to the circulation pipe, extracting heat from the first heat exchanger 3 through radiation and finned heat transfer. Or, both the first heat exchanger 3 and the circulation pipe at that location can be coil structures, intersecting each other, with the two types of pipes staggered, close together, or adjacent to each other for radiative heat transfer. Alternatively, a heat exchange block may be provided at the first heat exchanger 3, with multiple slots or through slots at the heat exchange block. The circulation pipe is inserted into the slots or passes through the through slots to extract heat through the heat exchange block. There are no requirements or restrictions on the connection between the circulation pipe and the first heat exchanger 3, or on the heat exchange method. The heat extraction refers to the heat exchange process. In cooling mode, the heat extraction is that the refrigerant obtains cold energy from the first heat exchanger 3 and releases cold energy into the room when it circulates to the indoor heat exchange unit, thereby cooling the room. In heating mode, the heat extraction is that the refrigerant obtains heat from the first heat exchanger 3 and provides heat to the middle room when it circulates to the indoor heat exchange unit, thereby raising the room temperature.

[0035] This invention facilitates heat transfer between the outdoor refrigeration system and the indoor heat exchange system through a first heat exchanger 3. The outdoor refrigeration system circulates refrigerant, while the indoor heat exchange system circulates a refrigerant. In this embodiment, the refrigerant and the refrigerant have different properties; the refrigerant is used for refrigeration circulation outside the carriage, while the refrigerant is used for circulating heat exchange inside the carriage. By setting up an indoor heat exchange system with circulating refrigerant, the refrigerant of the air conditioning unit is isolated from the carriage, completely eliminating the possibility of refrigerant remaining inside the carriage and improving the safety of rail vehicle operation.

[0036] The outdoor refrigeration system uses a refrigerant with high heat exchange efficiency. The refrigerant can be any one of R290 (propane), R32, R454B, R134a (1,1,1,2-tetrafluoroethane), R407C (a mixed refrigerant composed of R32, R125, and R134a), or R410A (a mixed refrigerant composed of R32 and R125). Based on considerations of low global warming potential, R290 (propane) is preferred. R290 has significant advantages in environmental protection, with an ozone depletion potential (ODP) of 0 and a global warming potential (GWP) of 3.3. The outdoor refrigeration system, which uses R290 refrigerant, is installed outside the vehicle compartment to prevent safety hazards such as fires caused by R290 leaks.

[0037] The refrigerant used in the indoor heat exchange system can be water, antifreeze, or other non-polluting, non-flammable or low-flammability (hereinafter collectively referred to as non-flammable) and non-corrosive liquids. Antifreeze is recommended to prevent the refrigerant from freezing in the outdoor section under low-temperature conditions. Using a non-flammable liquid refrigerant ensures leak-proof performance and does not corrode the piping.

[0038] An outdoor fan 7 is installed at the second heat exchanger 8 to assist in heat exchange and improve heat exchange efficiency.

[0039] An electronic expansion valve 6 is installed on the connecting pipe between the first heat exchanger 3 and the second heat exchanger 8 to regulate and control the refrigerant flow. The electronic expansion valve 6 regulates the refrigerant flow in the refrigerant circulation module by adjusting the opening degree in real time, thereby achieving accurate temperature control of the rail vehicle air conditioner.

[0040] The four-way reversing valve 2 has four four-way valve ports. Two of these ports are positioned opposite each other and connected to the two ports of the compressor 1, while the other two opposite ports are connected to the first heat exchanger 3 and the second heat exchanger 8, respectively. By controlling the connection method between the four-way reversing valve ports 2, the flow direction of the refrigerant is controlled, thereby enabling the switching between air conditioning cooling and heating modes.

[0041] It should be explained in detail that the outdoor refrigeration system includes a compressor 1 for refrigerant compression. The outlet of the compressor 1 is connected to a four-way reversing valve 2. The four-way reversing valve 2 includes a four-way valve first port 21, a four-way valve second port 22, a four-way valve third port 23, and a four-way valve fourth port 24. The compressor 1 is connected to the four-way valve first port 21, and the four-way valve third port 23 is connected to the inlet of the compressor 1. The four-way valve second port 22 is connected to a second heat exchanger 8. The other end of the second heat exchanger 8 is connected to an electronic expansion valve 6. The other end of the electronic expansion valve 6 is connected to a first heat exchanger 3, and the other end of the first heat exchanger 3 is connected to the four-way valve fourth port 24.

[0042] The outdoor refrigeration system also includes a refrigerant sensor 9 for detecting refrigerant leaks. The refrigerant sensor 9 is connected to the control module to transmit electrical signals indicating whether a refrigerant leak has occurred. When the refrigerant sensor 9 detects a refrigerant leak, the control module controls the outdoor fan 7 to operate, quickly dispersing the leaked refrigerant into the atmosphere and rapidly reducing the refrigerant concentration below the flammable range, thus preventing potential safety hazards outside the vehicle. In practical applications, any detector capable of detecting refrigerant leaks can be used, including but not limited to the refrigerant sensor 9 mentioned above, or any other device that performs a similar function.

[0043] Optionally, the outdoor refrigeration system also includes a refrigerant alarm device connected to the refrigerant sensor 9. When the refrigerant sensor 9 detects a refrigerant leak, the refrigerant alarm device will sound an alarm to inform the user that there is a refrigerant leak and that maintenance or shutdown of the air conditioning unit is required to reduce safety hazards.

[0044] The indoor heat exchange system includes an indoor heat exchange unit 11 for heat exchange between the refrigerant and the indoor atmosphere, and an indoor fan 12 for accelerating indoor heat exchange. The indoor heat exchange unit 11 primarily utilizes the heat exchange of the refrigerant to transfer heat to the room, thereby changing the indoor air temperature. The indoor fan 12 circulates air, regulates indoor airflow, increases the heat exchange rate of the indoor heat exchange unit 11, and accelerates indoor air circulation. In practical applications, the indoor heat exchange unit 11 and the indoor fan 12 work closely together. The indoor heat exchange unit 11 heats or cools the air, and then, driven by the indoor fan 12, the heat-exchanged air is delivered into the room, thus achieving the purpose of indoor temperature control and air circulation.

[0045] The indoor heat exchange system includes a liquid supply pump 5, which is installed on the circulation pipeline. The circulation pipeline at the outlet end extends outside the carriage to the first heat exchanger 3. After exchanging heat with the first heat exchanger 3, the circulation pipeline that exits is connected to the indoor heat exchange unit 11. The other end of the indoor heat exchange unit 11 is connected to the inlet end of the liquid supply pump 5. The liquid supply pump 5, the first heat exchanger 3, and the indoor heat exchange unit 11 are all connected by circulation pipelines. An expansion tank 4 is installed on the circulation pipeline between the pump and the first heat exchanger 3 to balance the pressure fluctuations caused by thermal expansion and contraction of the water in the system.

[0046] As an embodiment of this utility model, the indoor heat exchange system also includes an expansion tank 4 for balancing pressure fluctuations in the system's water circuit, especially for pressure fluctuations in the circulation pipeline caused by thermal expansion and contraction of the refrigerant when the ambient temperature changes significantly. The expansion tank 4 is installed on the circulation pipeline between the first heat exchanger 3 and the indoor heat exchanger.

[0047] The expansion tank 4 can balance the pressure fluctuations caused by the thermal expansion and contraction of the refrigerant in the system, effectively alleviate the pressure changes of the refrigerant (liquid), reduce or avoid the impact and damage to the circulation pipeline, and protect the safe and stable operation of the indoor heat exchange system.

[0048] The expansion tank 4 includes a tank body, an expander, a safety valve, and connecting pipes. The tank body has a certain volume to store a certain amount of refrigerant. The expander is a key component of the expansion tank 4, usually located inside the tank body. The expander is filled with compressed air or nitrogen. When the refrigerant in the expansion tank 4 expands due to heat, the compressed air or nitrogen is compressed, thus buffering and stabilizing the pressure. The safety valve is used to regulate the pressure inside the expansion tank 4 to prevent the expansion tank from bursting or other safety problems due to excessive pressure. The connecting pipes connect the expansion tank 4 to the circulation pipes, ensuring that the refrigerant in the expansion tank 4 can maintain smooth circulation with the liquid supply system.

[0049] The liquid supply system includes a liquid storage container that can store a certain amount of refrigerant and can supply a certain amount of refrigerant to the expansion tank 4.

[0050] In practical applications, the electronic expander 6 may not be required. Under normal conditions, when the refrigerant is not circulating, the refrigerant in the expansion tank 4 only occupies part of the tank body, meaning it does not completely fill the expansion tank 4, leaving some free space. The capacity of the refrigerant in the expansion tank 4 and the size of the free space can be determined based on the number of expansion systems of the refrigerant used. At high temperatures, the refrigerant expands, and the refrigerant in the circulation pipeline enters the expansion tank 4. The air in the free space is compressed. When the pressure reaches the threshold, the safety valve opens, venting the air from the expansion tank 4. At low temperatures, the refrigerant contracts, and the refrigerant in the expansion tank 4 enters the circulation pipeline. The pressure in the free space of the expansion tank 4 decreases. When the pressure drops to the threshold, the safety valve opens again, allowing outside air to enter the expansion tank 4.

[0051] Furthermore, the refrigerant circulation module also includes an indoor temperature sensor 10 to detect the temperature inside the rail vehicle car in real time. The indoor temperature sensor 10 transmits the detected interior temperature to the control module. The control module determines whether to operate in ventilation mode, cooling mode, or heating mode based on the detected interior temperature, and determines whether the interior temperature has reached the preset temperature, in order to control whether to stop or operate at low power consumption.

[0052] In the above embodiments, those skilled in the art can install the expansion tank 4 and the liquid supply pump 5 inside the rail vehicle car to avoid excessive temperature changes outside the car body causing equipment damage and thus affecting the service life of the expansion tank 4 and the liquid supply pump 5.

[0053] like Figure 1 As shown, in this embodiment, the air conditioning unit includes an outdoor cooling system and an indoor heat exchange system. Each outdoor cooling system corresponds to one indoor heat exchange system, which are respectively located outside and inside the vehicle compartment, and are interconnected outside the vehicle compartment through a first heat exchanger 3 and a circulation pipeline. The indoor heat exchange system includes an indoor heat exchange unit 11.

[0054] Preferred, such as Figure 2 As shown, each indoor heat exchange system may include multiple indoor heat exchange units 11 arranged in parallel. These multiple indoor heat exchange units 11 can be distributed at different locations within the carriage to effectively regulate the temperature inside the carriage and prevent localized overheating. Alternatively, multiple indoor heat exchange units 11 can be distributed in two or more adjacent carriages, simultaneously regulating the temperature of multiple carriages. To prevent heat loss and fluid pressure loss during the long-distance flow of the refrigerant in the circulation pipeline, a secondary pressure pump can be installed on the circulation pipeline after heat exchange, especially on the circulation pipeline after the nth indoor heat exchange unit 11, to increase the circulation pressure of the pipeline. Furthermore, the circulation pipeline is covered with insulation material, and a heat tracing system is installed on the insulation material to maintain the real-time temperature of the refrigerant, ensuring that the temperature of each indoor heat exchange unit 11 is consistent, thus guaranteeing a uniform temperature throughout the carriage.

[0055] When there are multiple indoor heat exchange units 11, each indoor heat exchange unit 11 is connected in parallel. After the circulation pipeline takes heat from the first heat exchange system 3, the refrigerant after heat exchange is evenly distributed into each indoor heat exchange unit 11 under the action of the liquid supply pump 5, so that the temperature of each indoor heat exchange unit 11 is consistent.

[0056] Furthermore, there can be one or more indoor heat exchange systems, that is, the same outdoor refrigeration system can correspond to one or more indoor heat exchange systems. The first heat exchanger 3 can be connected to and exchange heat with the circulation pipelines of one or more indoor heat exchange systems at the same time, and there is no connection between the indoor heat exchange systems.

[0057] It is understood that each outdoor refrigeration system may correspond to one or more indoor heat exchange systems, and each indoor heat exchange system may include one or more indoor heat exchange units 11 connected in parallel. Those skilled in the art can determine the correspondence between the number of outdoor refrigeration systems and indoor refrigeration systems, as well as the number of indoor heat exchange units 11 in the indoor refrigeration system, based on energy efficiency requirements, vehicle interior space, refrigerant heat exchange capacity, and heat exchange efficiency of indoor heat exchange units 11.

[0058] like Figure 1 As shown in the figure, the outdoor refrigeration system is also equipped with a four-way reversing valve 2, which adjusts the flow direction of the refrigerant so that the outdoor refrigeration system has two working modes. When the first valve port 21 of the four-way valve is connected to the second valve port 22 of the four-way valve, and the third valve port 23 of the four-way valve is connected to the fourth valve port 24 of the four-way valve, the air conditioning unit operates in refrigeration mode.

[0059] When the first valve port 21 of the four-way valve is connected to the fourth valve port 24 of the four-way valve, and the second valve port 22 of the four-way valve is connected to the third valve port 23 of the four-way valve, the air conditioning unit operates in heating mode.

[0060] Cooling Mode: When the outside temperature is high and the interior needs cooling, the four-way reversing valve 2 switches to cooling mode, the compressor 1 starts, and the refrigerant enters the four-way reversing valve 2 from the compressor 1, passing sequentially through the second heat exchanger 8, the electronic expansion valve 6, and the first heat exchanger 3 before returning to the four-way reversing valve 2 and finally back to the compressor 1. At this time, the second heat exchanger 8 acts as a condenser, and the first heat exchanger 3 acts as an evaporator. The refrigerant absorbs heat in the evaporator, condensing from vapor to liquid. The circulation pipe is connected to the first heat exchanger 3, and the refrigerant carries away heat from the refrigerant in the circulation pipe of the interior heat exchange system, thus lowering the refrigerant temperature.

[0061] Heating Mode: When the air conditioning unit requires heating in the vehicle compartment, the four-way reversing valve 2 switches to heating mode, compressor 1 starts, and refrigerant enters the four-way reversing valve 2 from compressor 1, passing sequentially through the first heat exchanger 3, electronic expansion valve 6, and second heat exchanger 8 before returning to the four-way reversing valve 2 and finally back to compressor 1. At this time, the second heat exchanger 8 also functions as an evaporator, and the first heat exchanger 3 functions as a condenser. The refrigerant vaporizes in the first heat exchanger 3, releasing heat, which is then transferred to the secondary refrigerant through interconnection.

[0062] When the outdoor cooling system is running in either the cooling or heating mode, the indoor heat exchange system is in operation. The liquid supply pump 5 starts, driving the refrigerant through the indoor unit heat exchange unit 11 and the first heat exchanger 3 in the circulation pipeline, and finally returning to the liquid supply pump 5 to complete one refrigerant cycle.

[0063] As described above, in the air conditioning unit, the refrigerant circulates only in the outdoor refrigeration system. When passing through the first heat exchanger 3, the refrigerant exchanges heat with the heat transfer fluid. The cooled or heated heat transfer fluid enters the indoor heat exchange unit 11 through the circulation pipe for heat exchange, thereby achieving control of the indoor temperature of the rail vehicle.

[0064] In various embodiments of this application, the refrigerant is only circulated in the outdoor refrigeration system and does not enter the interior of the carriage. Heat exchange of the refrigerant occurs through the first heat exchanger 3 and the circulating refrigerant, thus confining the refrigerant operation system outdoors. Even if a refrigerant leak occurs, it is unlikely to affect the interior of the rail vehicle unit, reducing the possibility of a hazard after a refrigerant leak. Furthermore, the refrigerant sensor 9 installed in the outdoor refrigeration system can detect refrigerant leaks in a timely manner. When a refrigerant leak is detected, or when the leak exceeds a preset threshold, the refrigerant sensor 9 issues an early warning, and the outdoor fan 7 operates, allowing the refrigerant to be promptly dispersed and discharged outside the vehicle, preventing refrigerant from diffusing into the interior of the rail vehicle and causing safety hazards. Preferably, when the refrigerant leak exceeds the threshold, the outdoor refrigeration system is controlled to stop operating, stopping the refrigerant flow to reduce the leakage caused by high-efficiency refrigerant and refrigerants in different states during operation. After the outdoor refrigeration system stops operating, the outdoor fan 7 maintains its original operating mode and increases its operating speed and airflow to allow the leaked refrigerant to dissipate as quickly as possible.

[0065] Furthermore, when the air conditioning unit is running in cooling or heating mode, the indoor heat exchange system is in operation. The liquid supply pump 5 is started, and the refrigerant flows in the circulation pipeline under the drive of the liquid supply pump 5, and takes heat at the first heat exchanger 3. The heat obtained is released at the indoor heat exchange unit 11 to adjust the indoor temperature.

[0066] The indoor heat exchange system isolates the refrigerant from the interior of the vehicle through refrigerant circulation heat exchange. The refrigerant exists only in the outdoor refrigeration system outside the vehicle, thus eliminating the possibility of refrigerant leakage inside the vehicle.

[0067] When the air conditioning unit is in ventilation mode, the operation of the outdoor fan 7 is periodically monitored and controlled to promptly discharge any leaked refrigerant.

[0068] When the air conditioning unit is running in cooling or heating mode, the refrigerant sensor 9 monitors refrigerant leakage in real time. Similarly, a periodic monitoring method can also be used. Considering that for the same leak point, the leakage rate is greater when the refrigerant is running than when it is stationary, the monitoring cycle in this mode should be significantly shorter than that under shutdown conditions. For example, in shutdown mode, a test can be performed every 10 minutes, while in cooling or heating mode, a test can be performed every 3 minutes. In practical applications, the monitoring cycle can be set independently without any requirements or limitations.

[0069] Upon detection of a refrigerant leak, the air conditioning unit is shut down to prevent further leakage. Preferably, upon detection of a refrigerant leak, the outdoor refrigeration system is shut down first, while the indoor heat exchange system continues to operate to fully utilize the heat from the first heat exchanger 3, allowing the refrigerant to continue circulating and extracting heat from the first heat exchanger 3, thus maintaining a stable temperature inside the vehicle.

[0070] In heating mode, when the temperature at the first heat exchanger 3 is less than or equal to the set temperature inside the passenger compartment, and in cooling mode, when the temperature at the first heat exchanger 3 is greater than or equal to the set temperature inside the passenger compartment, the indoor heat exchange system is controlled to stop operating. Preferably, the indoor heat exchange system is also equipped with a heater. In heating mode, when the heat at the first heat exchanger 3 is no longer suitable for heat exchange with the refrigerant, the heater can be used to heat the refrigerant to maintain the temperature inside the passenger compartment; alternatively, the heat from the heater can be directly blown into the passenger compartment by a fan.

[0071] Preferably, the air conditioning unit is equipped with a refrigerant leakage threshold. When the refrigerant content in the housing detected by the refrigerant sensor 9 is greater than or equal to the threshold, an alarm is triggered, and the outdoor fan 7 is controlled to run to discharge the refrigerant.

[0072] Furthermore, a continuous range of refrigerant leakage is set, with each range corresponding to a different operating speed of the outdoor fan 7. It can also be set that in the minimum range, the outdoor fan 7 does not need to run, and the refrigerant can be diffused by the air convection generated when the vehicle is running.

[0073] Preferably, upon detection of a refrigerant leak, the outdoor cooling system is shut down, including the outdoor fan 7. After the outdoor fan 7 has completely stopped, the outdoor fan 7 is restarted based on a comparison of the currently detected refrigerant leak amount with the interval data, and operates at the set power.

[0074] Alternatively, upon detection of a refrigerant leak, the outdoor refrigeration system may be shut down. This means the compressor will stop operating and the refrigerant circulation will cease, while the outdoor fan will continue running at increased power to provide greater ventilation and accelerate refrigerant discharge. If the current ventilation volume is already at the maximum operating power of the outdoor fan 7, the current operating power will be maintained.

[0075] Furthermore, for cases where the refrigerant leakage is less than the threshold but greater than zero, a warning is issued, but the outdoor refrigeration system is kept in operation. Alternatively, if the air conditioning unit has multiple operating levels, at least one level can be lowered to allow the outdoor refrigeration system to operate at a low level. This maintains the indoor temperature while reducing the leakage. Similarly, the operating power of the outdoor fan 7 is increased to increase the ventilation volume.

[0076] After receiving a refrigerant leak warning, staff will formulate different repair methods based on the range of the leak. When multiple refrigerant sensors 9 are installed, the leak point can be determined based on the data values ​​of each sensor 9.

[0077] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. The implementation schemes in the above embodiments can also be further combined or replaced. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

[0078] After adopting the above technical solution, the vehicle-mounted air conditioning unit and its control method provided by this utility model have the following advantages compared with the prior art:

[0079] 1. By eliminating the indoor evaporator and using an indoor heat exchange system with circulating refrigerant to isolate the refrigerant of the air conditioning unit from the car, the possibility of refrigerant remaining in the car is completely eliminated, thus improving the safety of rail vehicle operation.

[0080] 2. By isolating the outdoor refrigeration system, the refrigerant is kept only in the outdoor unit, preventing evaporator leaks from leaking refrigerant into the vehicle. This not only avoids safety hazards inside the vehicle but also improves its widespread application.

[0081] 3. The refrigerant detector continuously monitors for refrigerant leaks. When a refrigerant leak is detected, the outdoor fan will be activated to quickly disperse the refrigerant into the outdoor atmosphere, rapidly reducing the refrigerant concentration to a flammable level and preventing potential safety hazards outside the vehicle.

[0082] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. The implementation schemes in the above embodiments can also be further combined or replaced. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A vehicle air conditioning pack, characterized by: The air conditioning unit includes an outdoor refrigeration system located outside the vehicle compartment and at least one indoor heat exchange system located inside the vehicle compartment. Different types of refrigerants and coolants circulate in the outdoor refrigeration system and the indoor heat exchange system, respectively. The coolant circulation pipeline of the indoor heat exchange system extends outside the vehicle compartment and connects to the outdoor refrigeration system for heat exchange.

2. The vehicle air conditioning pack of claim 1, wherein: The outdoor cooling system includes a first heat exchanger, and the circulation pipeline is connected to the first heat exchanger to achieve heat exchange.

3. The vehicle air conditioning pack of claim 1, wherein: The air conditioning unit is a split type, including an outdoor refrigeration system and a corresponding set of indoor heat exchange systems; or the air conditioning unit is a unit type, including an outdoor refrigeration system and multiple sets of indoor heat exchange systems connected in parallel.

4. An air conditioning pack for a vehicle as claimed in any one of claims 1 to 3 wherein: The indoor heat exchange system includes one or more indoor heat exchange units connected in parallel.

5. The vehicle air conditioning pack of claim 4, wherein: The circulation pipeline is covered with thermal insulation material.

6. The vehicle air conditioning pack of claim 4, wherein: A heat tracing system is installed on the circulation pipeline.

7. An air conditioning unit for a vehicle as claimed in any one of claims 1 to 3, wherein: The indoor heat exchange system includes an expansion tank that can balance pressure fluctuations in the pipeline.

8. A vehicle-mounted air conditioning unit as described in claim 7, characterized in that: The expansion tank includes an expander installed inside the tank body, and the expander is filled with compressed air or nitrogen to buffer and stabilize the pressure.

9. The vehicle air conditioning pack of claim 7, wherein: The expansion tank also includes a safety valve for adjusting the pressure inside the expansion tank.

10. An air conditioning unit for a vehicle as claimed in any one of claims 1 to 3, wherein: The outdoor refrigeration system includes a detector for detecting refrigerant leaks.

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