Waste exhaust air heat recovery system of air conditioning unit and railway vehicle air conditioning unit

Abstract

The utility model relates to an air conditioning unit exhaust air heat recovery system and a railway vehicle air conditioning unit, which comprise a first refrigerant loop formed by sequentially connecting a compressor, an outdoor heat exchanger, a first throttling device and an indoor heat exchanger through refrigerant pipelines, and further comprise a second refrigerant loop, the second refrigerant loop is formed by sequentially connecting the compressor, the waste discharge heat exchanger, a second throttling device and the fresh air heat exchanger through refrigerant pipelines, and fresh air and waste discharge air exchange heat with refrigerants in the fresh air heat exchanger and refrigerants in the waste discharge heat exchanger correspondingly. The fresh air heat exchanger, the second throttling device and the waste discharge heat exchanger serve as independent refrigerant flow paths to be connected with the compressor, fresh air and waste discharge air can exchange heat with refrigerants in the fresh air heat exchanger and refrigerants in the waste discharge heat exchanger respectively, and cooling and heating loads of the fresh air are greatly reduced; and the waste heat recovery rate of waste exhaust air is also greatly improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of rail vehicle air conditioning system technology, especially to an air conditioning unit waste exhaust heat recovery system and a rail vehicle air conditioning unit. BACKGROUND

[0002] In order to ensure the cleanliness of the air in the car and the comfort of the passengers, the waste gas in the car needs to be discharged, and the fresh air outside the car needs to be transported into the car. However, in the traditional rail vehicle, the discharged waste exhaust air is directly discharged into the external environment. Taking the refrigeration condition as an example, when the air conditioning unit is refrigerating, the temperature in the car is relatively low. When the waste exhaust air is directly discharged into the external environment, the cold energy carried by the waste exhaust air is not well utilized, and a large amount of cold energy in the car is lost at the same time.

[0003] In order to solve the above problems, in the prior art, a total heat exchanger is installed at the fresh air inlet. The fresh air inlet and the waste gas inlet are communicated with the total heat exchanger, and the fresh air and the waste exhaust air are subjected to total heat exchange in the total heat exchanger. However, the total heat exchanger still has the problem of low waste heat recovery rate.

[0004] Therefore, the utility model is provided. UTILITY MODEL CONTENT

[0005] The utility model mainly solves the technical problem of providing an air conditioning unit waste exhaust heat recovery system which can greatly reduce the fresh air cold and heat load, improve the waste exhaust heat recovery utilization rate, and improve the energy efficiency ratio of the air conditioning unit, and providing a rail vehicle air conditioning unit using the air conditioning unit waste exhaust heat recovery system.

[0006] To achieve the above purpose, the first technical scheme of the utility model is as follows:

[0007] An air conditioning unit waste exhaust heat recovery system, comprising a first refrigerant circuit formed by a compressor, an outdoor heat exchanger, a first throttling device and an indoor heat exchanger connected in sequence through a refrigerant pipeline, and further comprising a second refrigerant circuit formed by the compressor, a waste exhaust heat exchanger, a second throttling device and a fresh air heat exchanger connected in sequence through a refrigerant pipeline. Fresh air and waste exhaust air are subjected to heat exchange with refrigerant in the fresh air heat exchanger and the waste exhaust heat exchanger respectively.

[0008] Further, the flow path of the fresh air is configured such that the fresh air is mixed with return air after heat exchange in the fresh air heat exchanger, and then sent to the indoor after heat exchange in the indoor heat exchanger.

[0009] Further, the flow path of the waste exhaust air is configured such that the waste exhaust air is directly discharged to the outdoor after heat exchange in the waste exhaust heat exchanger.

[0010] Further, the fresh air heat exchanger is arranged in a fresh air duct, and the exhaust air heat exchanger is arranged in an exhaust air duct.

[0011] Further, in the full fresh air working mode, the first refrigerant circuit is controlled to be closed, and the second refrigerant circuit is controlled to be opened.

[0012] Further, in the full return air working mode, the first refrigerant circuit is controlled to be opened, and the second refrigerant circuit is controlled to be closed.

[0013] Further, in the refrigeration or heating working mode, the first refrigerant circuit and the second refrigerant circuit are both controlled to be opened, when the indoor temperature reaches the set temperature, the first refrigerant circuit is controlled to be closed, and the second refrigerant circuit is controlled to be delayed closed and the compressor is controlled to be delayed stopped.

[0014] Further, at least one switch valve is arranged on the first refrigerant circuit and / or the second refrigerant circuit to control the opening and closing of the refrigerant circuit.

[0015] Further, the first refrigerant circuit is provided with a first switch valve and a second switch valve, the first switch valve is arranged at the refrigeration inlet side of the outdoor heat exchanger, and the second switch valve is arranged at the refrigeration outlet side of the indoor heat exchanger, and the first switch valve and the second switch valve are simultaneously opened and simultaneously closed.

[0016] The second technical scheme of the utility model is:

[0017] The utility model discloses a kind of air conditioning unit of railway vehicle, using the air conditioning unit exhaust air heat recovery system as described above.

[0018] In conclusion, the air conditioning unit exhaust air heat recovery system and the air conditioning unit of railway vehicle provided by the utility model connect the fresh air heat exchanger, the second throttling device and the exhaust air heat exchanger as separate refrigerant flow path with compressor, and fresh air and exhaust air can exchange heat with refrigerant in fresh air heat exchanger and exhaust air heat exchanger respectively, using refrigerant as medium for heat transfer between fresh air and exhaust air, because the temperature difference between indoor exhaust air and refrigerant in exhaust air heat exchanger is larger, the condensation efficiency of refrigerant in exhaust air heat exchanger is improved, the temperature difference between fresh air and indoor return air is further reduced, the cooling and heating load of fresh air is greatly reduced, the energy efficiency ratio of air conditioning unit is improved, and the waste heat recovery utilization rate of exhaust air is also greatly improved.

[0019] The specific embodiments of the utility model will be described in further detail in combination with the drawings. DRAWINGS

[0020] The accompanying drawings are used to provide further understanding of the present application and serve as a part of the present application to explain the embodiments of the present application and their descriptions. However, the drawings shall not be construed as an improper limitation to the present application.

[0021] In the drawings:

[0022] Figure 1 is a structure schematic diagram of the air conditioning unit exhaust air heat recovery system of the present application.

[0023] In the drawings:

[0024] The first refrigerant circuit 1, the second refrigerant circuit 2, the compressor 3, the outdoor heat exchanger 4, the first throttling device 5, the indoor heat exchanger 6, the exhaust air heat exchanger 7, the second throttling device 8, the fresh air heat exchanger 9, and the four-way valve 10.

[0025] It should be noted that the drawings and the written description are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0026] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments will be described clearly and completely below in conjunction with the drawings of the embodiments of the present application. The following embodiments are used to illustrate the present application, but not to limit the scope of the present application.

[0027] In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be construed as a limitation to the present application.

[0028] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] As Figure 1The utility model provides a kind of air handling unit exhaust air heat recovery system, including first refrigerant circuit 1 and second refrigerant circuit 2.

[0030] Wherein, first refrigerant circuit 1 is sequentially connected by compressor 3, outdoor heat exchanger 4, first throttling device 5 and indoor heat exchanger 6 by refrigerant pipeline to form. Second refrigerant circuit 2 is sequentially connected by compressor 3, exhaust heat exchanger 7, second throttling device 8 and fresh air heat exchanger 9 by refrigerant pipeline, that is, exhaust heat exchanger 7, second throttling device 8 and fresh air heat exchanger 9 are connected in parallel with outdoor heat exchanger 4, first throttling device 5 and indoor heat exchanger 6 at the air inlet end and the air outlet end of compressor 3. Fresh air and refrigerant in fresh air heat exchanger 9 exchange heat, and exhaust air and refrigerant in exhaust heat exchanger 7 exchange heat.

[0031] The exhaust air recovery system connects fresh air heat exchanger 9, second throttling device 8 and exhaust heat exchanger 7 as a separate refrigerant flow path with compressor 3, forms a parallel refrigerant flow path with first refrigerant circuit 1, and no longer uses fresh air to exchange heat with exhaust air as in the prior art.

[0032] In this embodiment, preferably, the flow path of fresh air is configured to mix with return air after heat exchange in fresh air heat exchanger 9, and then heat exchange in indoor heat exchanger 6 before being sent to the indoor. The flow path of exhaust air is configured to be directly discharged to the outdoor after heat exchange in exhaust heat exchanger 7.

[0033] In summer cooling mode and winter heating mode, first refrigerant circuit 1 and second refrigerant circuit 2 are both turned on and put into work.

[0034] In summer refrigeration mode, the outdoor heat exchanger 4 is connected to the output of the compressor 3 through the four-way valve 10, the high-temperature and high-pressure gaseous refrigerant discharged by the compressor 3 is divided into two paths, one path enters the outdoor heat exchanger 4, and the other path enters the exhaust heat exchanger 7. The refrigerant entering the outdoor heat exchanger 4 exchanges heat with outdoor air, releases heat to condense into liquid refrigerant, and then enters the indoor heat exchanger 6 after throttling by the first throttling device 5. The refrigerant absorbs heat to evaporate into gas in the indoor heat exchanger 6, and finally returns to the compressor 3. At the same time, the refrigerant entering the exhaust heat exchanger 7 exchanges heat with indoor exhaust air, releases heat to condense into liquid refrigerant, and then enters the fresh air heat exchanger 9 after throttling by the second throttling device 8. The refrigerant absorbs heat to evaporate into gas in the fresh air heat exchanger 9, and finally also returns to the compressor 3.

[0035] After the outdoor fresh air with a higher temperature is introduced, it first exchanges heat with the low-temperature refrigerant in the fresh air heat exchanger 9, the temperature of the fresh air is lowered, the cooled fresh air is then mixed with the return air in the room, the mixed air exchanges heat with the low-temperature refrigerant in the indoor heat exchanger 6, and finally the mixed air after heat exchange in the indoor heat exchanger 6 is sent to the room to adjust the temperature of the indoor environment.

[0036] In winter heating mode, the indoor heat exchanger 6 is connected to the output of the compressor 3 through the four-way valve 10, the high-temperature and high-pressure gaseous refrigerant discharged by the compressor 3 is also divided into two paths, one path enters the indoor heat exchanger 6, and the other path enters the fresh air heat exchanger 9. The refrigerant entering the indoor heat exchanger 6 exchanges heat with indoor air, releases heat to condense into liquid refrigerant, and then enters the outdoor heat exchanger 4 after throttling by the first throttling device 5. The refrigerant absorbs heat to evaporate into gas in the outdoor heat exchanger 4, and finally returns to the compressor 3. At the same time, the refrigerant entering the fresh air heat exchanger 9 exchanges heat with outdoor fresh air, releases heat to condense into liquid refrigerant, and then enters the exhaust heat exchanger 7 after throttling by the second throttling device 8. The refrigerant exchanges heat with indoor exhaust air in the exhaust heat exchanger 7 and absorbs heat to evaporate into gas, and finally also returns to the compressor 3.

[0037] After the outdoor fresh air with a lower temperature is introduced, it first exchanges heat with the high-temperature refrigerant in the fresh air heat exchanger 9, the temperature of the fresh air is raised, the heated fresh air is then mixed with the return air in the room, the mixed air exchanges heat with the high-temperature refrigerant in the indoor heat exchanger 6, and finally the mixed air after heat exchange in the indoor heat exchanger 5 is sent to the room to adjust the temperature of the indoor environment.

[0038] The system exchanges heat between the indoor exhaust air and the refrigerant of the exhaust heat exchanger 7 in the summer cooling mode or the winter heating mode, and the exhaust air is discharged to the outdoor. Since the temperature of the indoor exhaust air is lower than the outdoor temperature in the summer cooling mode and higher than the outdoor temperature in the winter heating mode, the temperature difference between the refrigerant in the exhaust heat exchanger 7 and the exhaust air is larger than the temperature difference between the refrigerant in the outdoor heat exchanger 4 and the outdoor environment. The heat exchange efficiency of the refrigerant in the exhaust heat exchanger 7 is improved when the refrigerant exchanges heat with the indoor exhaust air with a lower or higher temperature, which is beneficial to further reduce the condensation temperature of the refrigerant, and further reduce the temperature of the refrigerant after throttling, increase the temperature difference between the fresh air and the refrigerant in the fresh air heat exchanger 9, and further reduce (in the cooling mode) or increase (in the heating mode) the temperature of the heat-exchanged fresh air, and further reduce the temperature difference between the fresh air and the indoor return air. Compared with the prior art, the temperature of the fresh air is directly exchanged with the exhaust air to increase or decrease the temperature of the fresh air, which is more beneficial to reduce the cooling and heating load of the fresh air, and is beneficial to improve the energy efficiency ratio of the air conditioning unit.

[0039] In the embodiment, it is further preferred that, in the cooling or heating mode, when the indoor temperature reaches the set temperature, the first refrigerant circuit 1 is controlled to be closed, the second refrigerant circuit 2 is controlled to continue to work, and the second refrigerant circuit 2 is also controlled to be delayed to be closed and the compressor 3 is delayed to be stopped. Only when the indoor temperature continues to decrease or continues to increase beyond the set range, the second refrigerant circuit 2 is closed and the compressor 3 is stopped. In this way, the waste heat of the exhaust air can be more fully recovered and utilized, and the cooling and heating load of the fresh air is reduced.

[0040] In the embodiment, a temperature sensor is further provided in the fresh air duct to detect the temperature of the fresh air. When the temperature of the fresh air is equal to the set temperature of the indoor environment, the second refrigerant circuit 2 is controlled to stop working. Therefore, in the cooling and heating mode, the second refrigerant circuit 2 can be in the on state for a long time, so as to continuously recover and utilize the heat in the exhaust air.

[0041] In the embodiment, when the air conditioning unit enters the full fresh air mode, the first refrigerant circuit 1 is controlled to be closed, the second refrigerant circuit 2 is controlled to be opened, and the compressor 3 works. The fresh air enters the indoor environment after being exchanged by the fresh air heat exchanger 9, so as to adjust the indoor environment temperature. In this way, even in the full fresh air mode, the waste heat of the exhaust air can be fully utilized, and the waste heat recovery rate of the exhaust air is improved.

[0042] In the embodiment, when the air conditioning unit enters the full return air mode, i.e. the fresh air inlet is closed, the first refrigerant circuit 1 is controlled to be opened, the second refrigerant circuit 2 is controlled to be closed, and the compressor 3 works. In this process, the return air directly exchanges heat with the indoor heat exchanger 6 and then enters the indoor environment, so as to adjust the indoor environment temperature.

[0043] In this embodiment, the fresh air heat exchanger 9 is preferably arranged in a fresh air duct (not shown in the figure) which is partitioned in the shell by a partition plate. One end of the fresh air duct is connected to the fresh air inlet on the shell, and the other end is connected to the return air cavity. Fresh air enters the fresh air inlet and flows along the fresh air duct, exchanges heat with the refrigerant in the fresh air heat exchanger 9, and then flows to the return air cavity. The fresh air and the return air mix in the return air cavity. This is advantageous for making the structure of the air conditioning unit more simple and compact, and for controlling the flow path of the fresh air so that the fresh air exchanges heat in the fresh air heat exchanger 9 before flowing into the return air cavity.

[0044] In this embodiment, the exhaust air heat exchanger 7 is preferably arranged in an exhaust air duct (not shown in the figure) which is also partitioned in the shell by a partition plate. One end of the exhaust air duct is connected to the indoor exhaust air inlet, and the other end is connected to the exhaust air outlet which is arranged on the shell of the air conditioning unit. This is advantageous for making the structure of the air conditioning unit more simple and compact, and for controlling the flow path of the exhaust air so that the exhaust air exchanges heat in the exhaust air heat exchanger 7 before flowing into the outdoor environment.

[0045] In this embodiment, the opening and closing of the first refrigerant circuit 1 and the second refrigerant circuit 2 can be controlled by controlling the opening or closing of the first throttling device 5 and the second throttling device 8. Since the first throttling device 5 is an electronic expansion valve and is arranged between the indoor heat exchanger 6 and the outdoor heat exchanger 4, when the indoor temperature is equal to the set temperature, although the first refrigerant circuit 1 is in the off state, part of the refrigerant flowing out of the compressor 3 circulates through the second refrigerant circuit 2, and the other part is temporarily stored in the pipeline of the first refrigerant circuit 1, which affects the heat recovery efficiency of the exhaust air. Therefore, in this embodiment, it is further preferred that at least one on-off valve (not shown in the figure) is additionally arranged on the first refrigerant circuit 1 and / or the second refrigerant circuit 2 to assist in controlling the opening and closing of the refrigerant circuit.

[0046] In this embodiment, it is further preferred that two on-off valves, i.e. a first on-off valve and a second on-off valve, are arranged on the first refrigerant circuit 1. The first on-off valve is arranged on the refrigerant inlet side of the outdoor heat exchanger 4, and the second on-off valve is arranged on the refrigerant outlet side of the indoor heat exchanger 6. The first on-off valve and the second on-off valve are simultaneously opened and closed.

[0047] In the cooling mode, the refrigerant flowing out of the compressor 3 first enters the outdoor heat exchanger 4 or the exhaust air heat exchanger 7. In this embodiment, by closing the first on-off valve, the refrigerant flow accumulated in the first refrigerant circuit 1 is reduced, thereby ensuring the heat recovery efficiency of the exhaust air.

[0048] Further, in the heating mode, the refrigerant flowing out of the compressor 3 first enters the fresh air heat exchanger 9 or the indoor heat exchanger 6, and if only the first switch valve is arranged, a large amount of refrigerant can still accumulate in the first refrigerant circuit 1, therefore, in the embodiment, a second switch valve is arranged on the first refrigerant circuit 1, and the second switch valve is arranged at the refrigeration outlet side of the indoor heat exchanger 6. In the heating mode, the refrigerant flowing out of the compressor 3 first enters the fresh air heat exchanger 9 or the indoor heat exchanger 6, and in the embodiment, by closing the second switch valve, the refrigerant flow accumulated in the first refrigerant circuit 1 is reduced, and the heat recovery efficiency of the exhaust air is ensured.

[0049] On the other hand, when the first switch valve and the second switch valve are arranged on the first refrigerant circuit 1 at the same time, in the refrigeration mode, the first switch valve is closed, and the refrigerant can be prevented from accumulating on the pipeline where the outdoor heat exchanger 4 is arranged, and in the process of flowing out of the fresh air heat exchanger 9 and flowing back to the compressor 3, the refrigerant can also be prevented from flowing back to the pipeline where the indoor heat exchanger 6 is arranged due to the closing of the second switch valve, so that the refrigerant flow on the second refrigerant circuit 2 is further ensured, and the heat recovery efficiency of the exhaust air is ensured. Therefore, in the embodiment, the first switch valve and the second switch valve are preferably opened and closed at the same time.

[0050] The air conditioning unit exhaust air heat recovery system provided by the utility model connects the fresh air heat exchanger, the second throttling device and the exhaust air heat exchanger as a single refrigerant flow path with the compressor, the fresh air and the exhaust air can exchange heat with the refrigerant in the fresh air heat exchanger and the exhaust air heat exchanger respectively, the refrigerant is used as the medium for heat transfer between the fresh air and the exhaust air, the temperature difference between the indoor exhaust air and the refrigerant in the exhaust air heat exchanger is larger, the condensation efficiency of the refrigerant in the exhaust air heat exchanger is improved, the temperature difference between the fresh air and the indoor return air is further reduced, the cold and hot load of the fresh air is greatly reduced, the energy efficiency ratio of the air conditioning unit is improved, and the waste heat recovery utilization rate of the exhaust air is greatly improved.

[0051] The utility model also provides a railway vehicle adopting the above-mentioned railway vehicle exhaust air heat recovery system, and the energy efficiency ratio of the railway vehicle air conditioning system is improved by recovering heat from the exhaust air.

[0052] The above merely describes preferred embodiments of the present application and is not intended to limit the present application in any form, although the present application has been disclosed as above with preferred embodiments, however, it is not intended to limit the present application, any person skilled in the art without departing from the technical scheme of the present application can make some changes or modifications to the above-mentioned technical content as equivalent embodiments, the implementation schemes in the above-mentioned embodiments can be further combined or replaced, as long as it does not deviate from the content of the technical scheme of the present application, any simple modification, equivalent change and modification made to the above-mentioned embodiments according to the technical essence of the present application still belongs to the scope of the present application.

Claims

1. An air conditioning unit waste air heat recovery system, comprising a first refrigerant circuit formed by sequentially connecting a compressor, an outdoor heat exchanger, a first throttling device, and an indoor heat exchanger via refrigerant piping, characterized in that: It also includes a second refrigerant circuit, which is formed by sequentially connecting the compressor, waste exhaust heat exchanger, second throttling device and fresh air heat exchanger through refrigerant pipelines. Fresh air and waste exhaust air exchange heat with the refrigerant in the fresh air heat exchanger and waste exhaust heat exchanger, respectively.

2. The waste air heat recovery system for air conditioning units according to claim 1, characterized in that: The flow path of the fresh air is configured such that the fresh air is mixed with the return air after heat exchange in the fresh air heat exchanger, and then sent to the room after heat exchange in the indoor heat exchanger.

3. The waste air heat recovery system for air conditioning units according to claim 1, characterized in that: The flow path of the waste exhaust air is configured such that the waste exhaust air is directly discharged outdoors after heat exchange in the waste exhaust heat exchanger.

4. The waste air heat recovery system for air conditioning units according to claim 1, characterized in that: The fresh air heat exchanger is installed inside the fresh air duct, and the waste exhaust heat exchanger is installed inside the waste exhaust duct.

5. The waste air heat recovery system for air conditioning units according to claim 1, characterized in that: In the fresh air operation mode, the first refrigerant circuit is shut down and the second refrigerant circuit is turned on.

6. The waste air heat recovery system for air conditioning units according to claim 1, characterized in that: In full return air operation mode, control the first refrigerant circuit to open and control the second refrigerant circuit to close.

7. The waste air heat recovery system for air conditioning units according to claim 1, characterized in that: In cooling or heating mode, both the first and second refrigerant circuits are turned on. When the indoor temperature reaches the set temperature, the first refrigerant circuit is turned off, and the second refrigerant circuit is turned off after a delay and the compressor is turned off after a delay.

8. The waste air heat recovery system for air conditioning units according to any one of claims 5-7, characterized in that: At least one switching valve is provided on the first refrigerant circuit and / or the second refrigerant circuit to control the on / off state of the refrigerant circuit.

9. The waste air heat recovery system for air conditioning units according to claim 8, characterized in that: The first refrigerant circuit is equipped with a first switching valve and a second switching valve. The first switching valve is located on the refrigeration inlet side of the outdoor heat exchanger, and the second switching valve is located on the refrigeration outlet side of the indoor heat exchanger. The first switching valve and the second switching valve are opened and closed simultaneously.

10. An air conditioning unit for rail vehicles, characterized in that: The waste air heat recovery system of the air conditioning unit as described in any one of claims 1-9 is adopted.

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