An energy-saving aircraft ground air conditioning system that operates stably around the clock

Abstract

The present invention discloses an energy-saving aircraft ground air conditioning system that operates stably around the clock. When one of the third evaporator and the fourth evaporator connected in parallel at the end of the air conditioning system is frosted during use, the switch of two groups of solenoid valves is controlled to change the flow direction of the refrigerant in the three-stage system and switch the other evaporator to work, so as to prevent the continuous increase of the frost layer on the surface of the original evaporator from deteriorating the heat transfer effect, thereby ensuring the stability of the unit's air supply temperature and realizing the all-weather uninterrupted operation of the aircraft ground air conditioning unit; at the same time, fresh air is introduced through the sixth or eighth air duct corresponding to the third evaporator or the fourth evaporator where the frosting phenomenon occurs. After the fresh air absorbs the cold energy of the frost layer and cools down, it can be directly sent to the first air duct and directly mixed with the fresh air that has passed through the first evaporator, that is, the recovered cold energy of the frost layer bears the required refrigeration capacity of the original first evaporator, reduces the input power consumption of the first-stage system, and realizes energy saving and consumption reduction of the entire air conditioning system.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to an energy-saving aircraft ground air conditioning system that operates stably around the clock. Background Art

[0002] Aircraft ground air conditioning units are special air conditioners with fresh air. During operation, the unit outlet temperature is required to be no higher than 2°C, so the surface temperature of the evaporator at the end of the unit is often lower than 0°C. When the surface temperature of the fins is lower than 0°C, the fin surface is prone to frost. The frost layer on the surface of the evaporator fins will increase the air flow resistance, increase the power consumption of the unit, reduce the refrigeration capacity of the system, and cause fluctuations in the supply air temperature. At present, the commonly used defrosting methods for aircraft ground air conditioning units are electric defrosting and hot gas defrosting. The shortcomings are: electric defrosting increases the power distribution power of the unit, while the power distribution capacity of many airports is fixed; hot gas defrosting switches the flow direction of the refrigerant through a four-way reversing valve, which easily causes the compressor suction pressure to increase and the energy loss to increase. At the same time, the conventional defrosting method not only cannot recycle the coldness of the frost layer on the fin surface, resulting in a waste of capacity, but also cannot meet the needs of the unit's stable supply air temperature and energy saving and consumption reduction. Summary of the invention

[0003] The present invention aims to solve the problem that the prior art cannot recycle the cold energy of the frost layer on the surface of the terminal evaporator fin, which easily causes capacity waste and cannot meet the requirements of stable air supply temperature and energy saving and consumption reduction of the unit.

[0004] The present invention proposes an energy-saving aircraft ground air conditioning system that operates stably around the clock, and the technical solution adopted is:

[0005] The air conditioning system includes an air supply system and primary, secondary and tertiary systems that cooperate with the air supply system to perform cooling and heating;

[0006] The air supply system includes a first evaporator, a second evaporator, a third evaporator and a fourth evaporator, and the first evaporator is connected to the primary system;

[0007] The second evaporator is connected to the secondary system;

[0008] The third evaporator and the fourth evaporator are connected in parallel and are respectively connected to the three-stage system;

[0009] A fourth solenoid valve and a sixth solenoid valve for changing the flow direction of the refrigerant in the three-stage system are respectively provided at the connection between the third evaporator and the three-stage system;

[0010] A fifth solenoid valve and a seventh solenoid valve for changing the flow direction of the refrigerant in the three-stage system are respectively provided at the connection between the fourth evaporator and the three-stage system;

[0011] A seventh air duct for air intake is provided at the air inlet of the first evaporator;

[0012] The air outlet of the first evaporator is connected to the air inlet of the second evaporator through the first air duct, the air outlet of the second evaporator is connected to the air inlet of the third evaporator through the second air duct, and the air outlet of the second evaporator is connected to the air inlet of the fourth evaporator through the third air duct;

[0013] The air outlet of the third evaporator is connected to the first air duct through the fourth air duct, and the air outlet of the fourth evaporator is connected to the first air duct through the fifth air duct, and the cold air that absorbs the coldness of the frost layer at the third evaporator or the fourth evaporator is mixed with the fresh air in the first air duct;

[0014] The fourth air duct is provided with a fifth air valve for controlling the fresh air flowing into the first air duct through the third evaporator; the air outlet of the third evaporator is also provided with a ninth air duct, and the ninth air duct is provided with a sixth air valve for controlling whether the fresh air in the ninth air duct is discharged;

[0015] The fifth air duct is provided with an eighth air valve for controlling the fresh air flowing into the first air duct through the fourth evaporator; the air outlet of the fourth evaporator is also provided with a tenth air duct, and the tenth air duct is provided with a seventh air valve for controlling whether the fresh air in the tenth air duct is discharged;

[0016] A sixth air duct connected to the second air duct and an eighth air duct connected to the third air duct are respectively provided on the left and right sides of the seventh air duct, and the seventh air duct is connected to the sixth air duct and the eighth air duct respectively;

[0017] The sixth air duct is provided with a first air valve for controlling the fresh air in the seventh air duct to flow into the third evaporator;

[0018] The eighth air duct is provided with a second air valve for controlling the fresh air in the seventh air duct to flow into the fourth evaporator.

[0019] In a further preferred embodiment of the technical solution of the present invention, the primary system includes a first compressor, a first four-way valve, a first condenser, a first liquid reservoir, a first throttle valve, a first gas-liquid separator and a first solenoid valve; the first compressor is respectively connected to the first condenser, the first evaporator and the first gas-liquid separator through the first four-way valve, and the first evaporator is connected to the first condenser through the first solenoid valve, the first liquid reservoir and the first throttle valve;

[0020] The secondary system includes a second compressor, a second four-way valve, a second condenser, a second liquid reservoir, a second throttle valve, a second gas-liquid separator and a second solenoid valve; the second compressor is connected to the second condenser, the second evaporator and the second gas-liquid separator respectively through the second four-way valve, and the second evaporator is connected to the second condenser through the second solenoid valve, the second liquid reservoir and the second throttle valve;

[0021] The three-stage system includes a third compressor, a third four-way valve, a third condenser, a third liquid reservoir, a third throttle valve, a third gas-liquid separator and a third solenoid valve; the third compressor is connected to the third condenser, the third evaporator, the fourth evaporator and the third gas-liquid separator respectively through the third four-way valve, and the third evaporator and the fourth evaporator are connected to the third condenser respectively through the third solenoid valve, the third liquid reservoir and the third throttle valve; it is used to realize heating or cooling functions as needed.

[0022] In a further preferred embodiment of the technical solution of the present invention, a first blower and a second blower are provided on the first air duct, the air inlet of the first blower is connected with the air outlet of the second blower, the air inlet of the second blower is respectively connected with the fourth air duct and the fifth air duct, the second blower is used to attract the fresh air in the fourth air duct or the fifth air duct into the first air duct, and the first blower is used to transfer the fresh air in the first air duct to the second evaporator.

[0023] In a further preferred embodiment of the technical solution of the present invention, a third air valve is provided on the second air duct to control the second evaporator to transfer fresh air to the third evaporator, and is used to control the on-off state of the second air duct to prevent the fresh air from being transferred to the third evaporator through the second evaporator when the surface of the third evaporator is frosted, thereby worsening the frosting degree of the third evaporator;

[0024] The third air duct is provided with a fourth air valve for controlling the second evaporator to transfer fresh air to the fourth evaporator; the fourth air valve is used to control the on-off state of the third air duct to avoid frost on the surface of the fourth evaporator, in which the fresh air passing through the second evaporator is transferred to the fourth evaporator, thereby worsening the degree of frost on the fourth evaporator.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. When frosting occurs on one of the third evaporator and the fourth evaporator connected in parallel at the end of the air-conditioning system during use, the present invention controls the switches of two groups of fourth solenoid valves and sixth solenoid valves, fifth solenoid valves and seventh solenoid valves to change the flow direction of the refrigerant in the three-stage system and switch the other evaporator to work, so as to prevent the continuous increase of the frost layer on the surface of the original evaporator and deteriorate the heat transfer effect, thereby ensuring the stability of the air supply temperature of the unit and realizing the all-weather uninterrupted operation of the aircraft ground air-conditioning unit.

[0027] 2. When frosting occurs on one of the third evaporator and the fourth evaporator connected in parallel at the end of the present invention during use, fresh air is introduced through the sixth or eighth air duct corresponding to the third evaporator or the fourth evaporator where frosting occurs, and after absorbing the cold energy of the frost layer and cooling down, it is directly sent into the first air duct through the fourth or fifth air duct, and directly mixed with the fresh air that has passed through the first evaporator. That is, the recovered cold energy of the frost layer takes on the required cooling capacity of the original first evaporator, thereby achieving energy saving and consumption reduction of the entire air-conditioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the overall schematic diagram of the air conditioning system;

[0029] Figure 2 It is a schematic diagram of the air supply system;

[0030] Explanation of the reference numerals: 1-first evaporator, 2-second evaporator, 3-third evaporator, 4-fourth evaporator, 5-first blower, 6-second blower, 8-first compressor, 9-first four-way valve, 10-first condenser, 11-first liquid reservoir, 12-first throttle valve, 13-first gas-liquid separator, 14-second compressor, 15-second four-way valve, 16-second condenser, 17-second liquid reservoir, 18-second throttle valve, 19-second gas-liquid separator, 20-third compressor, 21-third four-way valve, 22-third condenser, 23-third liquid reservoir, 24-third throttle valve, 25-third gas-liquid separator, 26- The first air valve, 27-the second air valve, 28-the third air valve, 29-the fourth air valve, 30-the fifth air valve, 31-the sixth air valve, 32-the seventh air valve, 33-the eighth air valve, 34-the first solenoid valve, 35-the second solenoid valve, 36-the third solenoid valve, 37-the fourth solenoid valve, 38-the fifth solenoid valve, 39-the sixth solenoid valve, 40-the seventh solenoid valve, 701-the first air duct, 702-the second air duct, 703-the third air duct, 704-the fourth air duct, 705-the fifth air duct, 706-the sixth air duct, 707-the seventh air duct, 708-the eighth air duct, 709-the ninth air duct, 710-the tenth air duct, 711-the eleventh air duct. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is described in detail below, but the protection scope of the present invention is not limited to the embodiments.

[0032] To make the content of the present invention more clearly understood, the following Figure 1 -Attached Figure 2 The specific implementation manner is further described.

[0033] like Figure 1-2 As shown, the present embodiment is an energy-saving aircraft ground air-conditioning system that operates stably around the clock, the air-conditioning system includes an air supply system and a primary, secondary and tertiary system; the air supply system includes a first evaporator 1, a second evaporator 2, a third evaporator 3, a fourth evaporator 4, a first air supply fan 5 and a second air supply fan 6.

[0034] The first evaporator 1 is arranged at the front end of the air supply system and connected to the primary system, the second evaporator 2 is arranged at the middle end of the air supply system and connected to the secondary system, and the third evaporator 3 and the fourth evaporator 4 are arranged in parallel at the end of the air supply system and connected to the tertiary system respectively.

[0035] The air outlet of the first evaporator 1 is connected to the air inlet of the second evaporator 2 through the first air duct 701, and the air outlet of the second evaporator 2 is connected to the air inlet of the third evaporator 3 and the fourth evaporator 4 through the second air duct 702 and the third air duct 703, respectively.

[0036] The air outlets of the third evaporator 3 and the fourth evaporator 4 are connected to the first air duct 701 through the fourth air duct 704 and the fifth air duct 705 respectively, and the cold air that absorbs the coldness of the frost layer at the third evaporator 3 or the fourth evaporator 4 is mixed with the fresh air in the first air duct 701.

[0037] like Figure 1 As shown, the primary system includes a first compressor 8, a first four-way valve 9, a first condenser 10, a first liquid reservoir 11, a first throttle valve 12, a first gas-liquid separator 13 and a first solenoid valve 34; the first compressor 8 is connected to the first condenser 10, the first evaporator 1 and the first gas-liquid separator 13 respectively through the first four-way valve 9, and the first evaporator 1 and the first condenser 10 are connected through the first solenoid valve 34, the first liquid reservoir 11 and the first throttle valve 12.

[0038] like Figure 1 As shown, the secondary system includes a second compressor 14, a second four-way valve 15, a second condenser 16, a second liquid reservoir 17, a second throttle valve 18, a second gas-liquid separator 19 and a second solenoid valve 35; the second compressor 14 is connected to the second condenser 16, the second evaporator 2 and the second gas-liquid separator 19 respectively through the second four-way valve 15, and the second evaporator 2 and the second condenser 16 are connected through the second solenoid valve 35, the second liquid reservoir 17 and the second throttle valve 18.

[0039] like Figure 1 As shown, the three-stage system includes a third compressor 20, a third four-way valve 21, a third condenser 22, a third liquid reservoir 23, a third throttle valve 24, a third gas-liquid separator 25 and a third solenoid valve 36; the third compressor 20 is connected to the third condenser 22, the third evaporator 3, the fourth evaporator 4 and the third gas-liquid separator 25 respectively through the third four-way valve 21, and the third evaporator 3, the fourth evaporator 4 and the third condenser 22 are connected through the third solenoid valve 36, the third liquid reservoir 23 and the third throttle valve 24.

[0040] In this embodiment, the various devices within the primary, secondary and tertiary systems are connected by pipelines, and the devices within the primary, secondary and tertiary systems are connected to the first evaporator 1, the second evaporator 2, the third evaporator 3 and the fourth evaporator 4 by pipelines.

[0041] In this embodiment, the third evaporator 3 and the fourth evaporator 4 are connected to the three-level system and share two identical pipelines. The third evaporator 3 is connected to the two pipelines through the fourth solenoid valve 37 and the sixth solenoid valve 39, which are used to control the on-off state between the third evaporator 3 and the three-level system; the fourth evaporator 4 is connected to the two pipelines through the fifth solenoid valve 38 and the seventh solenoid valve 40, which are used to control the on-off state between the fourth evaporator 4 and the three-level system; when the surface of the third evaporator 3 or the fourth evaporator 4 is frosted during operation, it is convenient to switch to the fourth evaporator 4 or the third evaporator 3 to continue working.

[0042] When the air-conditioning system realizes the refrigeration function, taking the first-level system as an example: the first solenoid valve 34 of the first-level system is closed; the first compressor 8 inhales low-temperature and low-pressure refrigerant, and the refrigerant becomes high-temperature and high-pressure gas after being compressed, flows through the first four-way valve 9 through the pipeline, enters the first condenser 10 for condensation to become high-pressure liquid, and then passes through the first liquid storage tank 11 and the first throttle valve 12 to become low-pressure liquid, vaporizes and absorbs heat in the first evaporator 1, so that the temperature of the surrounding air flow is reduced, and the refrigerant evaporated into low-pressure and low-temperature refrigerant in the first evaporator 1 is sucked into the first compressor 8 after passing through the first four-way valve 9 and the first gas-liquid separator 13 for the next refrigeration cycle.

[0043] Similarly, the operating principles of the refrigeration functions of the secondary system and the tertiary system are similar. At this time, the three-stage system only needs to activate one of the third evaporator 3 and the fourth evaporator 4; the primary, secondary, and tertiary systems turn on the refrigeration function, that is, the refrigerant evaporates and absorbs heat in the first evaporator 1, the second evaporator 2, the third evaporator 3 or the fourth evaporator 4, achieving a step-by-step cooling effect on the air temperature in each air duct and the surrounding air, thereby realizing the refrigeration function.

[0044] When the air-conditioning system realizes the heating function, take the first-level system as an example: when the air-conditioning system runs in the heating mode, the first solenoid valve 34 of the first-level system is opened; the first compressor 8 inhales low-temperature and low-pressure refrigerant, and the refrigerant is compressed to become a high-temperature and high-pressure gas, which flows through the first four-way valve 9 through the pipeline and enters the first evaporator 1 for condensation and heat release, thereby increasing the temperature of the surrounding air flow, and then passes through the first solenoid valve 34, the first liquid reservoir 11 and the first throttle valve 12 to become a low-pressure liquid, which is evaporated into a low-pressure and low-temperature refrigerant in the first condenser 10 and then sucked into the first compressor 8 through the first four-way valve 9 and the first gas-liquid separator 13 for the next heating cycle.

[0045] Similarly, the operating principles of the heating functions of the secondary system and the tertiary system are similar. At this time, the three-stage system only needs to activate one of the third evaporator 3 and the fourth evaporator 4; the primary, secondary, and tertiary systems turn on the heating function, that is, the refrigerant condenses and releases heat in the first evaporator 1, the second evaporator 2, the third evaporator 3 or the fourth evaporator 4, achieving a step-by-step heating effect on the ambient air temperature in each air duct, thereby realizing the heating function.

[0046] The air inlet of the first evaporator 1 is connected to the seventh air duct 707 to provide external fresh air for the first evaporator 1. The seventh air duct 707 is connected to the sixth air duct 706 and the eighth air duct 708. The sixth air duct 706 and the eighth air duct 708 are symmetrically arranged on the left and right sides of the seventh air duct 707. The sixth air duct 706 is connected to the second air duct 702 to provide external fresh air for the third evaporator 3 to defrost the third evaporator 3. The eighth air duct 708 is connected to the third air duct 703 to provide external fresh air for the fourth evaporator 4 to defrost the fourth evaporator 4.

[0047] The sixth air duct 706 and the eighth air duct 708 are respectively provided with a first air valve 26 and a second air valve 27. The first air valve 26 on the sixth air duct 706 is used for when frost forms on the surface of the third evaporator 3. The first air valve 26 is opened to introduce part of fresh air from the seventh air duct 707 into the third evaporator 3 for defrosting. The second air valve 27 on the eighth air duct 708 is used for when frost forms on the surface of the fourth evaporator 4. The second air valve 27 is opened to introduce part of fresh air from the seventh air duct 707 into the fourth evaporator 4 for defrosting.

[0048] The air outlet of the first evaporator 1 is connected to the air inlet of the second evaporator 2 via the first air duct 701 , so that the fresh air that has passed through the first evaporator 1 is transferred to the second evaporator 2 .

[0049] The air outlet of the second evaporator 2 is connected to the air inlet of the third evaporator 3 and the fourth evaporator 4 through the second air duct 702 and the third air duct 703 respectively. The second air duct 702 and the third air duct 703 are respectively provided with a third air valve 28 and a fourth air valve 29, which is convenient for judging whether the fresh air acted on by the second evaporator 2 is transmitted to the third evaporator 3 or the fourth evaporator 4 according to the on-off state between the three-level system and the third evaporator 3 and the fourth evaporator 4. If the third evaporator 3 is connected with the three-level system, the third air valve 28 is in an open state at this time, and the fresh air acted on by the second evaporator 2 is transmitted to the third evaporator 3. If the fourth evaporator 4 is connected with the three-level system, the fourth air valve 29 is in an open state at this time, and the fresh air acted on by the second evaporator 2 is transmitted to the fourth evaporator 4.

[0050] The air outlet of the third evaporator 3 is connected to the fourth air duct 704 and the ninth air duct 709 respectively, and the other end of the fourth air duct 704 is connected to the first air duct 701. When the surface of the third evaporator 3 is frosted and the third evaporator 3 is not connected to the three-level system, the surface frost layer of the third evaporator 3 is taken away by the external fresh air introduced by the sixth air duct 706 to remove the frost layer cold energy, and the fresh air carrying the frost layer cold energy is transferred to the first air duct 701 for recycling and mixed with the fresh air that has passed through the first evaporator 1, so as to further save energy and reduce consumption.

[0051] A fifth air valve 30 is provided on the fourth air duct 704, which is used to control the opening and closing of the fourth air duct 704 when the third evaporator 3 is connected to the three-level system to prevent the new air that has passed through the first evaporator 1, the second evaporator 2 and the third evaporator 3 from returning to the first air duct 701.

[0052] The ninth air duct 709 is connected to the eleventh air duct 711, and is used for discharging the fresh air that has passed through the third evaporator 3 when the third evaporator 3 is connected to the three-level system. The ninth air duct 709 is provided with a sixth air valve 31, which is used for transferring the fresh air that has recovered the cold energy of the frost layer of the third evaporator 3 to the first air duct 701 in cooperation with the fifth air valve 30 when the surface of the third evaporator is frosted and the third evaporator 3 is not connected to the three-level system.

[0053] The air outlet of the fourth evaporator 4 is connected to the fifth air duct 705 and the tenth air duct 710 respectively, and the other end of the fifth air duct 705 is connected to the first air duct 701. When frost forms on the surface of the fourth evaporator 4 and the fourth evaporator 4 is not connected to the three-level system, the surface frost layer of the fourth evaporator 4 is taken away by the external fresh air introduced by the eighth air duct 708 to remove the frost cold, and the fresh air carrying the frost cold is transferred to the first air duct 701 for recycling and mixed with the fresh air that has passed through the first evaporator 1, so as to further save energy and reduce consumption.

[0054] The fifth air duct 705 is provided with an eighth air valve 33, which is used to control the opening and closing of the fifth air duct 705 when the fourth evaporator 4 is connected to the three-level system to prevent the new air that has passed through the first evaporator 1, the second evaporator 2 and the third evaporator 3 from returning to the first air duct 701.

[0055] The tenth air duct 710 is connected to the eleventh air duct 711, and is used for discharging the fresh air that has passed through the fourth evaporator 4 when the fourth evaporator 4 is connected to the three-level system. The tenth air duct 710 is provided with a seventh air valve 32, which is used to cooperate with the eighth air valve 33 to transfer the fresh air that recovers the cold energy of the frost layer of the fourth evaporator 4 to the first air duct 701 when the surface of the fourth evaporator 4 is frosted and the fourth evaporator 4 is not connected to the three-level system.

[0056] The first air duct 701 is also provided with a first air supply fan 5 and a second air supply fan 6. The air inlet of the first air supply fan 5 is connected with the air outlet of the second air supply fan 6 through the first air duct 701. The first evaporator 1 is used to transfer the fresh air that has passed through the first evaporator 1 to the second evaporator 2; the air inlet of the second air supply fan 6 is connected with the fourth air duct 704 and the fifth air duct 705 respectively, so as to facilitate the transfer of the fresh air that has absorbed the cold energy of the frost layer in the fourth air duct 704 or the fifth air duct 705 to the first air duct 701 to be absorbed and transferred by the first fan 5.

[0057] The specific method of using the energy-saving aircraft ground air conditioning system that operates stably around the clock of the present invention is as follows: when the air conditioning system does not need to defrost for refrigeration, taking the third evaporator 3 as an example: close the fifth solenoid valve 38 and the seventh solenoid valve 40, open the fourth solenoid valve 37 and the sixth solenoid valve 39, and the refrigerant of the three-level system flows into the third evaporator 3; open the third air valve 28 and the sixth air valve 31, and close the remaining air valves, and the external fresh air enters the first evaporator 1 from the seventh air duct 707, and under the action of the first blower 5, passes through the second evaporator 2 and the third evaporator 3 in sequence, and is cooled to form cold air below 2°C, thereby achieving refrigeration.

[0058] When the air-conditioning system needs to be defrosted and cooled at the same time, taking the frosting phenomenon on the third evaporator 3 as an example, the fourth solenoid valve 37 and the sixth solenoid valve are closed, and the fifth solenoid valve 38 and the seventh solenoid valve are opened. At this time, the refrigerant of the three-stage system flows into the fourth evaporator 44; the first air valve 26, the fourth air valve 29, the fifth air valve 30, and the seventh air valve 32 are opened, and the remaining air valves are closed.

[0059] External fresh air enters the first evaporator 1 from the seventh air duct 707, and under the action of the first air supply fan 5, passes through the first air duct 701, the second evaporator 2, the third air duct 703, the fourth air valve 29, the fourth evaporator 4, the tenth air duct 710 and the seventh air valve 32 in sequence, and is cooled to form cold air below 2°C, thereby achieving refrigeration.

[0060] The cold air flowing into the second evaporator 2 consists of two parts. One part is the cold air formed by the external fresh air being directly cooled down by the first evaporator 1. The other part is the cold air formed by the external fresh air entering the third evaporator 3 through the sixth air duct 706 under the action of the second air supply fan 6, and absorbing the cold energy of the frost layer on the surface of the third evaporator 3. The cold air reaches the first air duct 701 through the fourth air duct 704, and is mixed with the cold air formed by the cooling down of the first evaporator 1 and enters the second evaporator 2 for further cooling down.

[0061] Similarly, when frost appears on the fourth evaporator 4, the fifth solenoid valve 38 and the seventh solenoid valve 40 are closed, and the fourth solenoid valve 37 and the sixth solenoid valve 39 are opened. At this time, the three-stage system refrigerant flows into the third evaporator 33. The second air valve 27, the third air valve 28, the sixth air valve 31, and the eighth air valve 33 are opened, and the remaining air valves are closed. Under the action of the blower 5, the external fresh air enters the first evaporator 1 through the seventh air duct 707. Under the action of the first blower 5, the external fresh air passes through the first air duct 701, the second evaporator 2, the second air duct 702, the third air valve 28, the third evaporator 3, the ninth air duct 709 and the sixth air valve 31 in sequence, and is cooled to form cold air below 2°C, thereby achieving refrigeration.

[0062] The cold air flowing into the second evaporator 2 consists of two parts. One part is the cold air formed by the external fresh air being directly cooled by the first evaporator 1. The other part is the cold air formed by the external fresh air entering the fourth evaporator 4 through the eighth air duct 708 under the action of the second air supply fan 6, and absorbing the cold energy of the frost layer on the surface of the fourth evaporator 4. The cold air reaches the first air duct 701 through the fifth air duct 705, and is mixed with the cold air formed by the cooling of the first evaporator 1 and enters the second evaporator 2 for further cooling.

[0063] When the air-conditioning system needs to realize the heating function, take the selection of the third evaporator 3 as an example: close the fifth solenoid valve 38 and the seventh solenoid valve 40, open the fourth solenoid valve 37 and the sixth solenoid valve 39, and the refrigerant of the three-level system flows into the third evaporator 3; open the third air valve 28 and the sixth air valve 31; open the first solenoid valve 34 in the first-level system, the second solenoid valve 35 in the second-level system, and the third solenoid valve 36 in the third-level system, and the external fresh air enters the first evaporator 1 through the seventh air duct 707, and under the action of the first blower 5, it is heated and heated by the second evaporator 2 and the third evaporator 3 in turn to realize heating.

[0064] The parts not involved in the present invention are the same as the prior art or can be implemented by using the prior art.

[0065] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes in form and details may be made without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. An energy-saving aircraft ground air conditioning system that operates stably around the clock, characterized in that: The air conditioning system includes an air supply system and primary, secondary and tertiary systems that cooperate with the air supply system to perform cooling and heating; The air supply system comprises a first evaporator (1), a second evaporator (2), a third evaporator (3) and a fourth evaporator (4), wherein the first evaporator (1) is connected to the primary system; The second evaporator (2) is connected to the secondary system; The third evaporator (3) and the fourth evaporator (4) are connected in parallel to the three-stage system; A fourth solenoid valve (37) and a sixth solenoid valve (39) for changing the flow direction of the refrigerant in the three-stage system are respectively provided at the connection between the third evaporator (3) and the three-stage system; A fifth solenoid valve (38) and a seventh solenoid valve (40) for changing the flow direction of the refrigerant in the three-stage system are respectively provided at the connection between the fourth evaporator (4) and the three-stage system; A seventh air duct (707) for air intake is provided at the air inlet of the first evaporator (1); The air outlet of the first evaporator (1) is connected to the air inlet of the second evaporator (2) via a first air duct (701), the air outlet of the second evaporator (2) is connected to the air inlet of the third evaporator (3) via a second air duct (702), and the air outlet of the second evaporator (2) is connected to the air inlet of the fourth evaporator (4) via a third air duct (703); The air outlet of the third evaporator (3) is connected to the first air duct (701) via the fourth air duct (704), and the air outlet of the fourth evaporator (4) is connected to the first air duct (701) via the fifth air duct (705), and the cold air that absorbs the coldness of the frost layer at the third evaporator (3) or the fourth evaporator (4) is mixed with the fresh air in the first air duct (701); The fourth air duct is provided with a fifth air valve (30) for controlling the fresh air passing through the third evaporator (3) to flow into the first air duct (701); the air outlet of the third evaporator (3) is also provided with a ninth air duct (709), and the ninth air duct (709) is provided with a sixth air valve (31) for controlling whether the fresh air in the ninth air duct (709) is discharged; An eighth air valve (33) is provided on the fifth air duct for controlling the fresh air passing through the fourth evaporator (4) to flow into the first air duct; a tenth air duct (710) is also provided at the air outlet of the fourth evaporator (4); a seventh air valve (32) is provided at the tenth air duct (710) for controlling whether the fresh air in the tenth air duct (710) is discharged; A sixth air duct (706) connected to the second air duct (702) and an eighth air duct (708) connected to the third air duct (703) are respectively provided on the left and right sides of the seventh air duct (707); the seventh air duct (707) is respectively connected to the sixth air duct (706) and the eighth air duct (708); The sixth air duct (706) is provided with a first air valve (26) for controlling the fresh air in the seventh air duct (707) to flow into the third evaporator (3); The eighth air duct (708) is provided with a second air valve (27) for controlling the fresh air in the seventh air duct (707) to flow into the fourth evaporator (4).

2. The energy-saving aircraft ground air conditioning system that operates stably around the clock according to claim 1, characterized in that: The primary system comprises a first compressor (8), a first four-way valve (9), a first condenser (10), a first liquid reservoir (11), a first throttle valve (12), a first gas-liquid separator (13) and a first solenoid valve (34); the first compressor (8) is connected to the first condenser (10), the first evaporator (1) and the first gas-liquid separator (13) respectively through the first four-way valve (9); the first evaporator (1) and the first condenser (10) are connected through the first solenoid valve (34), the first liquid reservoir (11) and the first throttle valve (12); The secondary system comprises a second compressor (14), a second four-way valve (15), a second condenser (16), a second liquid reservoir (17), a second throttle valve (18), a second gas-liquid separator (19) and a second solenoid valve (35); the second compressor (14) is respectively connected to the second condenser (16), the second evaporator (2) and the second gas-liquid separator (19) via the second four-way valve (15); the second evaporator (2) and the second condenser (16) are connected via the second solenoid valve (35), the second liquid reservoir (17) and the second throttle valve (18); The three-stage system comprises a third compressor (20), a third four-way valve (21), a third condenser (22), a third liquid storage tank (23), a third throttle valve (24), a third gas-liquid separator (25) and a third solenoid valve (36); the third compressor (20) is respectively connected to the third condenser (22), the third evaporator (3), the fourth evaporator (4) and the third gas-liquid separator (25) via the third four-way valve (21); the third evaporator (3) and the fourth evaporator (4) are respectively connected to the third condenser (22) via the third solenoid valve (36), the third liquid storage tank (23) and the third throttle valve (24).

3. The energy-saving aircraft ground air conditioning system that operates stably around the clock according to claim 1, characterized in that: The first air duct (701) is provided with a first air supply fan (5) and a second air supply fan (6); the air inlet of the first air supply fan (5) is connected to the air outlet of the second air supply fan (6); and the air inlet of the second air supply fan (6) is connected to the fourth air duct (704) and the fifth air duct (705), respectively.

4. The energy-saving aircraft ground air conditioning system that operates stably around the clock according to claim 1, characterized in that: The second air duct (702) is provided with a third air valve (28) for controlling the second evaporator (2) to transfer fresh air to the third evaporator (3); The third air duct (703) is provided with a fourth air valve (29) for controlling the second evaporator (2) to transfer fresh air to the fourth evaporator (4).

Images