CN105716334A - Subway train air conditioning unit with exhaust air subcooler - Google Patents

Abstract

The invention relates to an air-conditioning unit for subway trains with an exhaust supercooler, the air-conditioning unit includes a refrigerant circuit and an air circuit; the refrigerant circuit is filled with refrigerant, including a compressor, a condenser, and a throttling device and an evaporator, the refrigerant circuit also includes a subcooler, wherein the compressor, condenser, subcooler, throttling device and evaporator are sequentially connected in a cycle; the air circuit includes an evaporator air circuit, an overcooler cooler air circuit and condenser air circuit. Compared with the prior art, the present invention uses the exhaust air of the compartment for cooling without consuming additional energy, and adds a subcooler to increase the cooling efficiency of the air conditioning unit. The simulation results show that after adding the subcooler, the refrigeration performance system 9% improvement.

Description

A subway train air conditioning unit with an exhaust air subcooler

technical field

The invention relates to an air-conditioning unit for a subway train, in particular to an air-conditioning unit for a subway train with an exhaust supercooler.

Background technique

Air conditioners in subway trains are mostly cold-only systems. In the existing air-conditioning units of subway trains, the exhaust air in the compartment is directly discharged to the outdoor environment through the exhaust fan and the air duct, and there is a huge waste of cooling capacity. In addition, the size of air-conditioning units for subway trains is strictly limited, the heat exchange effect of the heat exchanger is poor, and the cooling efficiency of the units is low.

Contents of the invention

The object of the present invention is to provide a subway train air-conditioning unit with an exhaust air subcooler with low energy consumption and good refrigeration efficiency in order to overcome the above-mentioned defects in the prior art.

The object of the present invention can be achieved through the following technical solutions: a subway train air-conditioning unit with an exhaust air subcooler, the air-conditioning unit includes a refrigerant circuit and an air circuit; the refrigerant circuit is provided with a refrigerant, including compressor, condenser, throttling device and evaporator, and the refrigerant circuit also includes a subcooler, wherein the compressor, condenser, subcooler, throttling device and evaporator are sequentially connected in a cycle; the described The air circuit includes the evaporator air passage and the subcooler air passage;

The air circuit of the evaporator includes an evaporator and a blower fan connected in sequence, the refrigerant is used to cool the mixed gas of the fresh air outside the compartment and the return air in the train, and the mixed gas is sent back to the compartment through the blower fan;

The air circuit of the subcooler includes a subcooler and an exhaust fan connected in sequence, and the refrigerant in the refrigerant circuit is cooled by the air in the compartment.

A refrigerant subcooler is added to the refrigerant circuit to cool the refrigerant with the low-temperature gas in the compartment. On the one hand, it can reduce the condensation temperature and improve the operation reliability and safety of the unit; on the other hand, it can increase the unit mass flow rate of the refrigeration unit. Cooling capacity, making the same cooling capacity can reduce the frequency of the compressor and significantly improve the efficiency of the unit.

The condenser includes a condenser refrigerant channel and a condenser air channel, the condenser refrigerant channel is a part of the refrigerant circuit, the inlet of the condenser air channel communicates with the air outside the compartment, and the condenser air The outlet of the channel communicates with the air outside the compartment through the condensing fan, and uses the air outside the compartment to cool the refrigerant in the refrigerant circuit, and uses the air outside the compartment to cool the refrigerant in the refrigerant circuit.

The subcooler includes a subcooler refrigerant channel and a subcooler air channel, the subcooler refrigerant channel is a part of the refrigerant circuit, and the inlet of the cooler air channel passes through the No. 1 exhaust air channel The mouth is connected with the air in the compartment, and the outlet of the cooler air channel is communicated with the air outside the compartment through the exhaust fan, and the cold air in the compartment is used to cool the refrigerant in the refrigerant circuit again.

The throttling device includes a capillary tube, a short tube, an electronic expansion valve, a thermal expansion valve or an orifice.

The evaporator includes an evaporator refrigerant channel and an evaporator air channel, the evaporator refrigerant channel is a part of the refrigerant circuit, the evaporator air channel is a part of the air circuit, and the evaporator air channel inlet The gas mixer communicates with the air outside the compartment and the air inside the compartment, and the outlet of the air channel of the evaporator communicates with the air inside the compartment through the blower fan, and uses the refrigerant in the refrigerant circuit to cool the mixed air.

A filter is arranged between the gas mixer and the inlet of the air channel of the evaporator, so as to improve the air quality of the air supply to the compartment.

In the refrigerant circuit, firstly, under the action of the compressor, the low-temperature and low-pressure refrigerant vapor turns into high-temperature and high-pressure steam, which releases heat and condenses into a high-temperature and high-pressure liquid in the condenser, and enters the subcooler to be further cooled, and the supercooled refrigerant The liquid enters the evaporator through the throttling device, absorbs heat and evaporates in the evaporator to become a low-temperature and low-pressure refrigerant vapor, and completes the refrigeration cycle.

In the air circuit, the outdoor fresh air enters the air duct through the fresh air outlet and mixes with the return air in the compartment. The mixed air first enters the evaporator through the air duct, is cooled and dehumidified in the evaporator, and then is sent into the car.

The present invention can improve the operating reliability and refrigeration efficiency of the air-conditioning unit of the subway train. , to avoid high-voltage protection, which is conducive to improving the reliability and safety of the unit operation; in addition, the temperature of the exhaust air in the compartment is significantly lower than that of the outdoor air, and the exhaust air from the compartment enters the subcooler for heat exchange, which has a better cooling effect and can effectively increase the system overheating. Increase the cooling capacity per unit of refrigerant flow, thereby improving the cooling efficiency of the train air conditioning unit.

Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects:

(1) Use the exhaust air of the compartment for cooling without consuming additional energy;

(2) Integrate all or part of the exhaust air duct into the air conditioning unit, and add a refrigerant subcooler. The cooling capacity recovered by the subcooler increases the system subcooling degree, increases the unit cooling capacity, and reduces the system cooling capacity. The agent flow path reduces the condensing pressure, reduces the compressor capacity, and improves the energy efficiency ratio of the unit. The simulation results show that after adding a subcooler, the refrigeration performance system of the train air conditioning unit increases from 2.2 to 2.4, an increase of 9%.

Description of drawings

Fig. 1 is a connection diagram of the present invention.

Among them, 1 is the compressor, 2 is the condenser, 3 is the subcooler, 4 is the throttling device, 5 is the evaporator, 6 is the compartment, 7 is the air supply fan, 8 is the exhaust fan, 9 is the condensing fan, 10-18 are refrigerant connecting pipes, 21 is the air return port, 22 is the fresh air port, 23 is the air supply port, 24 is the No. 1 exhaust port, 25 is the No. 2 exhaust port, 26 is the suction port, and 27 is the air outlet. 31-41 are air ducts.

detailed description

The embodiments of the present invention are described in detail below. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following implementation example.

Example 1

An air-conditioning unit for subway trains with an exhaust air subcooler, its structure and process are shown in Figure 1. The air-conditioning unit includes a refrigerant circuit and an air circuit.

The refrigerant circuit includes a compressor 1, a condenser 2, a subcooler 3, a throttling device 4, and an evaporator 5 that are sequentially connected in circulation, wherein the condenser 2, the subcooler 3, and the evaporator 5 all include refrigerant passages and Air channel, in the refrigerant circuit, the condenser 2, the subcooler 3 and the evaporator 5 are all connected to the refrigerant channel, and the specific process is as follows: the low-temperature and low-pressure refrigerant vapor coming out of the evaporator 5 refrigerant channel is refrigerated The refrigerant connecting pipe 18 enters the compressor 1, and becomes a high-temperature and high-pressure refrigerant vapor under the action of the compressor 1; enters the refrigerant passage of the condenser 2 through the refrigerant connecting pipe 14, and condenses to become a high-temperature and high-pressure refrigerant through exothermic condensation Liquid; enter the refrigerant channel of the subcooler 3 through the refrigerant connecting pipe 15, be further cooled by the exhaust air of the compartment, become a supercooled liquid, enter the throttling device 4 through the refrigerant connecting pipe 16; then pass through the refrigerator connecting pipe 17 enters the refrigerant channel of the evaporator 5, becomes low-temperature and low-pressure refrigerant vapor through heat absorption and evaporation, and returns to the compressor through the refrigerant connecting pipe 18 to complete the refrigeration cycle.

The air circuit includes the evaporator air passage and the subcooler air passage.

Wherein, the air circuit of the subcooler sucks the air in the compartment 6 into the air passage of the supercooler 3 through the No. 1 air outlet 24 and the air pipe 36, and utilizes the air to cool the refrigerant in the refrigerant passage of the supercooler 3, and By air duct 37, exhaust fan 8 and air duct 38, air is discharged outside the car compartment through No. 2 air outlet 14 successively.

The air circuit of the evaporator sucks the air in the cabin 6 through the air return port 21 and the air duct 31, and sucks the air outside the compartment through the fresh air port 22 and the air duct 32, and the two airs are mixed and enter the air channel of the evaporator 5 through the air duct 33 , after utilizing the cooling capacity in the refrigerant channel of the evaporator 5 to cool, it passes through the air pipe 34, the air blower 7 and the air pipe 35 successively, and is sent back to the compartment 6 through the air outlet 23. Before the evaporator 5, a filter is arranged to improve the air quality of the air supply to the compartment.

In addition, the air passage of the condenser draws the air outside the cabin into the air passage of the condenser 2 through the air suction port 26 and the air pipe 39, and uses the air to cool the refrigerant in the refrigerant passage of the condenser 2, and passes through the air pipe 40, The condensing fan 9 and the air pipe 41 discharge the air out of the compartment through the air outlet 27 .

The simulation results show that after the subcooler is added, the refrigeration performance of the train air-conditioning unit increases from 2.2 to 2.4, an increase of 9%.

All the components of the refrigerant cycle and air duct are not fully shown in the above embodiments. During the implementation process, common refrigeration accessories such as high-pressure liquid receivers, gas-liquid separators, oil separators, filters, and dryers are installed in the refrigerant circuit. Install filters, mufflers, humidifiers, heaters, sterilizers and other air treatment accessories in the air duct, select different air supply outlets and return air grilles, change the position of the fan, or add a heat exchanger without departing from the spirit of the technical solution of the present invention , Fans and air valves, etc., cannot be regarded as substantive improvements to the present invention, and should belong to the protection scope of the present invention.

Words such as "No. 1" and "No. 2" are used in this article to define components. Those skilled in the art should know that the words "No. 1" and "No. 2" are used only for the convenience of description to distinguish the above-mentioned components. Unless otherwise stated, the above terms have no special meanings.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those of ordinary skill in the art can still modify the specific implementation methods of the present invention or perform equivalent replacements to some technical features, but As long as they do not deviate from the spirit of the technical solutions of the present invention, they should be included in the scope of the technical solutions claimed in the present invention.

Claims (6)

1. A subway train air-conditioning unit with an exhaust subcooler, the air-conditioning unit comprises a refrigerant circuit and an air circuit; charging refrigerant in the described refrigerant circuit includes a compressor, a condenser, a throttling device and The evaporator is characterized in that the refrigerant circuit also includes a subcooler, wherein the compressor, condenser, subcooler, throttling device and evaporator are sequentially connected in a cycle; the air circuit includes an evaporator air passages and subcooler air passages; The air path of the evaporator includes an evaporator and a blower fan connected in sequence, the refrigerant is used to cool the mixed gas of the fresh air outside the compartment and the return air in the train, and the mixed gas is sent back to the compartment through the blower fan; The air path of the subcooler includes a subcooler and an exhaust fan connected in sequence, and uses the air in the compartment to cool the refrigerant liquid in the refrigerant circuit. 2. A subway train air-conditioning unit with an exhaust air subcooler according to claim 1, wherein said condenser comprises a condenser refrigerant passage and a condenser air passage, and said condenser cools The refrigerant passage is a part of the refrigerant circuit, the inlet of the air passage of the condenser communicates with the air outside the compartment, and the outlet of the air passage of the condenser communicates with the air outside the compartment through a condensing fan, and the air outside the compartment is used to cool the refrigerant in the refrigerant circuit. agent. 3. A kind of subway train air-conditioning unit with exhaust subcooler according to claim 1, characterized in that, said subcooler comprises a subcooler refrigerant channel and a subcooler air channel, said The refrigerant channel of the subcooler is a part of the refrigerant circuit. The inlet of the air channel of the subcooler communicates with the air in the compartment through the air outlet, and the outlet of the air channel of the subcooler communicates with the air outside the compartment through the exhaust fan. 4. A subway train air-conditioning unit with an exhaust subcooler according to claim 1, wherein the throttling device comprises a capillary, a short tube, an electronic expansion valve, a thermal expansion valve or an orifice. 5. A subway train air-conditioning unit with an exhaust air subcooler according to claim 1, wherein the evaporator includes an evaporator refrigerant channel and an evaporator air channel, and the evaporator cooling The agent channel is a part of the refrigerant circuit, and the evaporator air channel is a part of the air circuit. The inlet of the evaporator air channel communicates with the air outside the compartment and the air in the compartment through the gas mixer, and the outlet of the air channel of the evaporator passes through the air blower. It communicates with the air in the cabin. 6. A subway train air-conditioning unit with an exhaust subcooler according to claim 5, characterized in that a filter is arranged between the gas mixer and the evaporator air passage inlet.