Quaternary heat recovery type air conditioning unit

Abstract

The utility model relates to the technical field of dehumidification air conditioning units, and particularly discloses a quaternary heat recovery type air conditioning unit which comprises an air conditioning filter, a front heat recovery heat exchanger, a main heat exchanger, a rear heat recovery heat exchanger, a reheating heat exchanger and an air feeder. The heat recovery exhaust unit comprises an exhaust filter, an exhaust heat recovery heat exchanger and an exhaust fan; the heat pump device comprises a compressor, a three-way valve and a four-way reversing valve; the heat pump system is arranged between the air conditioning unit and the exhaust unit, cold of exhausted air is recycled in summer and used for precooling, deep dehumidification and reheating of inlet air of the air conditioning unit, the evaporation temperature of the rear heat recycling heat exchanger of the heat pump is low, deep dehumidification can be achieved, the cold source temperature of the main heat exchanger can be increased, and the heat pump system can be used for heat exchange of the air conditioning unit. The energy efficiency of the cold source is improved; and in winter, heat of exhaust air can be recycled and used for preheating and reheating inlet air of the air conditioning unit, the air supply temperature can be stabilized through reheating, and constant temperature and humidity are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of dehumidifying air-conditioning units, and particularly relates to a four-element heat recovery type air-conditioning unit. Background Technique

[0002] Heat recovery units are mostly applied to the heat recovery between fresh air and exhaust air in industrial and civil buildings. Heat recovery units are widely used in most areas of our country. Especially in environments such as hospitals, office buildings, libraries, hotels, laboratories, public transportation buildings, production workshops, etc., where there is a large amount of exhaust air and there is a large temperature difference or enthalpy difference between fresh air and exhaust air.

[0003] Common heat recovery forms include plate heat recovery, rotary wheel heat recovery, solution heat recovery, heat pipe heat recovery, etc. However, the above devices can only be recovered by heat transfer during heat recovery, and the recovered energy is restricted by the enthalpy difference between the recovered air and the air to be recovered. And the heat recovery system constructed by a heat pump can achieve higher heat recovery through the phase change of the refrigerant. Even if the enthalpy difference between the recovered air and the air to be recovered is very small, due to the phase change of the refrigerant used for energy transfer, there is a larger temperature difference between the refrigerant and the air. And through the switching of pipelines and the adjustment of expansion valves, not only can the energy recovery of the exhaust air be realized, but also the low-temperature refrigerant can be used for deep dehumidification of the air, and the high-temperature refrigerant can be used for air reheating, meeting the temperature control and humidity control requirements of the air handling unit, achieving three goals with one action.

[0004] Therefore, there is an urgent need to design a four-element heat recovery type air-conditioning unit to solve the problem that the current air-conditioning unit is restricted by a large temperature difference or enthalpy difference. Content of the Utility Model

[0005] Aiming at the problems existing in the prior art, the purpose of the utility model is to provide a four-element heat recovery type air-conditioning unit. By setting a heat pump device between the air-conditioning unit and the exhaust fan unit, the cold quantity of the exhaust air can be recovered under the summer refrigeration condition, the incoming air of the air-conditioning unit can be precooled, and at the same time, the air can be deeply dehumidified and reheated; under the summer heating condition, the heat of the exhaust air can be recovered, the incoming air of the air-conditioning unit can be preheated, the unit can be protected from freezing, and at the same time, the humidified air can be reheated, achieving four goals with one action. And the heat recovery efficiency is as high as more than 75%.

[0006] The technical solution adopted by the utility model to solve its technical problems is: a four-element heat recovery type air-conditioning unit, including a heat recovery air-conditioning unit, a heat recovery exhaust fan unit and a heat pump device. The heat recovery air-conditioning unit includes an air-conditioning filter, a preheat recovery heat exchanger, a main heat exchanger, a postheat recovery heat exchanger, a reheating heat exchanger, and a supply fan. The heat recovery exhaust fan unit includes an exhaust filter, an exhaust heat recovery heat exchanger, and an exhaust fan. The heat pump device includes a compressor, a three-way valve, and a four-way reversing valve;

[0007] The exhaust port of the compressor is connected to the inlet of the three-way valve. One outlet of the three-way valve is connected to the inlet of the reheating heat exchanger. The other outlet of the three-way valve is connected to the inlet of the four-way reversing valve in parallel with the outlet of the reheating heat exchanger. A check valve I is arranged on the outlet of the reheating heat exchanger. One reversing outlet of the four-way reversing valve is connected to the inlet of the exhaust air heat recovery heat exchanger. The other reversing outlet of the four-way reversing valve is connected to the pipeline in parallel with the outlets of the preheating heat recovery heat exchanger and the postheating heat recovery heat exchanger. A check valve II is arranged on the outlet pipeline of the postheating heat recovery heat exchanger. The outlet of the four-way reversing valve is connected to the suction port of the compressor.

[0008] Specifically, two paths are branched out from the outlet of the exhaust air heat recovery heat exchanger. One path of the outlet of the exhaust air heat recovery heat exchanger is connected to the inlet of the postheating heat recovery heat exchanger through the heating electronic expansion valve and the main electronic expansion valve. The other path of the outlet of the exhaust air heat recovery heat exchanger is connected to the inlet of the preheating heat recovery heat exchanger through the auxiliary electronic expansion valve.

[0009] Specifically, the heating electronic expansion valve is connected in parallel with a check valve IV, and the auxiliary electronic expansion valve is connected in parallel with a check valve III.

[0010] Specifically, the heat pump device is provided with four sets of pipelines, and the four sets of pipelines are respectively connected to the preheating heat recovery heat exchanger, the postheating heat recovery heat exchanger, the reheating heat exchanger in the heat recovery air-conditioning unit and the exhaust air heat recovery heat exchanger in the heat recovery exhaust fan unit.

[0011] Specifically, the main heat exchanger is connected to an external cold and heat source device through a pipeline, and the external cold and heat source device adopts one of an air-cooled heat pump, a chilled water host, an air-cooled direct expansion machine and a water-cooled direct expansion machine.

[0012] Specifically, the preheating heat recovery heat exchanger, the main heat exchanger, the postheating heat recovery heat exchanger, the reheating heat exchanger and the exhaust air heat recovery heat exchanger are all finned heat exchangers.

[0013] Specifically, an air-conditioning filter is installed at the air inlet of the heat recovery air-conditioning unit, a blower is installed at the air outlet of the heat recovery air-conditioning unit, an exhaust filter is installed at the air return inlet of the heat recovery exhaust fan unit, and an exhaust fan is installed at the air exhaust outlet of the heat recovery exhaust fan unit.

[0014] Specifically, both the blower and the exhaust fan adopt one of an AC motor and a DC brushless EC motor.

[0015] Specifically, the air inlet of the heat recovery air-conditioning unit takes in outdoor fresh air or indoor return air or a mixture of fresh and return air.

[0016] The utility model has the following beneficial effects:

[0017] The four-element heat recovery air conditioner unit designed by the utility model realizes the recovery of the cold of the exhaust air in summer by arranging a heat pump system between the air conditioner unit and the exhaust fan unit, and is used for precooling the incoming air of the air conditioner unit, deep dehumidification and reheating. Since the evaporation temperature of the post-heat recovery heat exchanger of the heat pump is relatively low, it can meet the requirement of deep dehumidification. Therefore, the cold source temperature of the main heat exchanger can be increased, the energy efficiency of the cold source can be improved, and at the same time, the condensation heat of the heat pump can be used free of charge to reheat the dehumidified air to achieve the purpose of constant temperature and humidity. In winter, the heat of the exhaust air can be recovered and used for preheating and reheating the incoming air of the air conditioner unit. Especially for the system with enthalpy equalizing humidification, the temperature after the humidifier becomes lower, and the supply air temperature can be stabilized by reheating to achieve constant temperature and humidity, and the heat recovery efficiency is as high as over 75%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a four-element heat recovery air conditioner unit.

[0019] In the figure: 1. Heat recovery air conditioner unit box; 2. Heat recovery exhaust fan unit box; 3. Heat pump device; 4. External cold and heat source device; 1-1. Air conditioner filter; 1-2. Pre-heat recovery heat exchanger; 1-3. Main heat exchanger; 1-4. Post-heat recovery heat exchanger; 1-5. Reheat heat exchanger; 1-6. Supply fan; 2-1. Exhaust air filter; 2-2. Exhaust air heat recovery heat exchanger; 2-3. Exhaust fan; 3-1. Compressor; 3-2. Three-way valve; 3-3. Check valve I; 3-4. Four-way reversing valve; 3-5. Main electronic expansion valve; 3-6. Sub-electronic expansion valve; 3-7. Check valve II; 3-8. Check valve III; 3-9. Check valve IV; 3-10. Heating electronic expansion valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The technical solutions in the embodiments of the present utility model will be further described clearly and completely below with reference to the accompanying drawings in the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0021] As Figure 1 shown, a four-element heat recovery air conditioner unit includes a heat recovery air conditioner unit 1, a heat recovery exhaust fan unit 2, a heat pump device 3 and a heat recovery pipeline.

[0022] It should be noted that the heat recovery exhaust fan unit 2 includes: an exhaust air filter 2-1, an exhaust air heat recovery heat exchanger 2-2, and an exhaust fan 2-3.

[0023] It should be noted that the heat recovery air conditioner unit 1 includes: an air conditioner filter 1-1, a pre-heat recovery heat exchanger 1-2, a main heat exchanger 1-3, a post-heat recovery heat exchanger 1-4, a reheat heat exchanger 1-5, and a supply fan 1-6.

[0024] It should be noted that the heat pump device 3 includes: a compressor 3-1, a three-way valve 3-2, a four-way reversing valve 3-4, a first check valve 3-3, a second check valve 3-7, a third check valve 3-8, and a fourth check valve 3-9, a main electronic expansion valve 3-5, a sub-electronic expansion valve 3-6, a heating expansion valve 3-10, and pipelines.

[0025] It should be noted that the heat pump device 3 has four sets of pipelines (one inlet and one outlet is a set). Among them, e-1 and e-2 are respectively connected to the inlet and outlet of the preheat recovery heat exchanger 1-2 in the heat recovery air conditioner unit, d-1 and d-2 are respectively connected to the inlet and outlet of the postheat recovery heat exchanger 1-4, c-1 and c-2 are respectively connected to the inlet and outlet of the reheating heat exchanger 1-5, and o-1 and o-2 are respectively connected to the inlet and outlet of the exhaust air heat recovery heat exchanger 2-2 in the heat recovery exhaust fan unit.

[0026] It should be noted that the exhaust port of the compressor 3-1 is connected to the inlet of the three-way valve 3-2. The outlet a of the three-way valve 3-2 is connected to the inlet c-1 of the reheating heat exchanger 1-5. The outlet c-2 of the reheating heat exchanger 1-5 is connected to the inlet f-1 of the first check valve 3-3. After the outlet b of the three-way valve 3-2 is connected to the outlet f-2 of the check valve 3-3, it is then connected to the inlet i of the four-way reversing valve 3-4 in a parallel manner; the outlet m of the four-way reversing valve 3-4 is connected to the inlet o-1 of the exhaust air heat recovery heat exchanger 2-2. The outlet j is connected to the outlet e-2 of the preheat recovery heat exchanger 1-2 and the outlet g-2 of the second check valve 3-7 in a parallel manner respectively. The outlet d-2 of the postheat recovery heat exchanger 1-4 is connected to the inlet g-1 of the second check valve 3-7; the outlet k of the four-way reversing valve 3-4 is connected to the suction port of the compressor 3-1; the outlet o-2 of the exhaust air heat recovery heat exchanger 2-2 is branched into two paths. The outlet o-2 is connected to the third check valve 3-9 and the heating expansion valve 3-10 in a parallel manner. The outlet o-2 of the exhaust air heat recovery heat exchanger 2-2 is branched into two paths. One path is connected to the h-2 port of the main electronic expansion valve 3-5, and one path is connected to the p-2 port of the sub-electronic expansion valve 3-6. The h-1 port of the main electronic expansion valve 3-5 is connected to the inlet d-1 of the postheat recovery heat exchanger 1-4. The p-1 port of the sub-electronic expansion valve 3-6 is connected to the inlet e-1 of the preheat recovery heat exchanger. The heating electronic expansion valve 3-10 is in parallel with the fourth check valve 3-9, and the sub-electronic expansion valve 3-6 is in parallel with the third check valve 3-8.

[0027] It should be noted that when the heat recovery air conditioner unit 1 is in refrigeration mode, the heat pump device 3 operates according to the refrigeration condition. The front heat recovery heat exchanger 1-2 and the rear heat recovery heat exchanger 1-4 become evaporators, the reheating heat exchanger 1-5 becomes the primary condenser, and the exhaust air heat recovery heat exchanger 2-2 becomes the secondary condenser. The air is first purified by the filter 1-1, then pre-cooled by the front heat recovery heat exchanger 1-2 in sequence, further cooled and dehumidified by the main heat exchanger 1-3, then deeply dehumidified by the rear heat recovery heat exchanger 1-4, and finally reheated by the reheating heat exchanger 1-5. The refrigerant flow direction of the heat pump device 3 is that the high-temperature and high-pressure refrigerant discharged from the compressor 3-1 passes through the three-way valve 3-2. When the condensation heat needs to be used for reheating, the port a of the three-way valve 3-2 is opened and the port b is closed, and the high-temperature and high-pressure refrigerant flows into the reheating heat exchanger 1-5, which can reheat the air flowing through the reheating heat exchanger 1-5. When reheating is not required, the port b of the three-way valve 3-2 is opened and the port a is closed, and the high-temperature and high-pressure refrigerant flow is blocked by the check valve 1 3-3 and cannot enter the reheating heat exchanger 1-5. The high-temperature refrigerant flowing out of the reheating heat exchanger 1-5 or directly flowing out of the port b of the three-way valve 3-2 flows into the i port of the four-way reversing valve 3-4, then flows out of the m port and enters the exhaust air heat recovery heat exchanger 2-2 through the o-1 port. The high-temperature and high-pressure refrigerant entering the heat recovery heat exchanger 2-2 exchanges heat with the exhaust air, dissipates the heat into the exhaust air, and becomes a high-pressure liquid, then flows out through the o-2 port. The liquid refrigerant flowing out through the o-2 port flows out through the check valve 4 3-9. At this time, the heating expansion valve 3-10 is closed. After flowing out of the check valve 4 3-9, it is divided into two paths. One path is throttled by the auxiliary electronic expansion valve 3-6 and then enters the front heat recovery heat exchanger 1-2, and the other path is throttled by the main electronic expansion valve 3-5 and then enters the rear heat recovery heat exchanger 1-4. The liquid refrigerant evaporated in the evaporator becomes a gaseous state, and converges into the j port of the four-way reversing valve 3-4 through the d-2 and e-2 ports respectively, and then returns to the compressor 3-1 through the k port to complete the cycle.

[0028] It should be noted that when the heat recovery air conditioner unit 2 is in heating mode, the heat pump device 3 operates according to the heating condition. The reheater 1-5 is still the primary condenser, the front heat recovery heat exchanger 1-2 becomes the secondary condenser, and the rear heat recovery heat exchanger 1-4 does not work (the refrigerant entry is cut off by the one-way valve 3-3 and the main electronic expansion valve 3-5). The exhaust air heat recovery heat exchanger 2-2 becomes the evaporator. The refrigerant flow direction of the heat pump device 3 is that the high-temperature and high-pressure refrigerant discharged from the compressor 3-1 passes through the three-way valve 3-2. When the condensation heat is needed for reheating, port a of the three-way valve 3-2 is opened and port b is closed, and the high-temperature and high-pressure refrigerant flows into the reheater 1-5, which can reheat the air flowing through the reheater 1-5. When reheating is not needed, port b of the three-way valve 3-2 is opened and port a is closed, and the high-temperature and high-pressure refrigerant flow is blocked by the one-way valve 3-3 and cannot enter the reheater 1-5. The high-temperature refrigerant flowing out of the reheater 1-5 or the high-temperature refrigerant directly flowing out of port b of the three-way valve 3-2 flows into port i of the four-way reversing valve 3-4, then flows out of port j and enters the front heat recovery heat exchanger 1-2 through port e-2. The high-temperature and high-pressure refrigerant entering the front heat recovery heat exchanger 1-2 exchanges heat with the air in the heat recovery air conditioner unit 1, dissipates the heat into the air, and becomes a high-pressure liquid, and then flows out through port e-1. The liquid refrigerant flowing out through port e-1 flows out through the one-way valve 3-8. At this time, the auxiliary electronic expansion valve 3-6 is closed. The refrigerant flowing out of the one-way valve 3-8 is throttled by the heating electronic expansion valve 3-10 and then enters the exhaust air heat recovery heat exchanger 2-2. After evaporating in the evaporator, the liquid refrigerant becomes a gaseous state, enters port m of the four-way reversing valve 3-4 through port o-1 respectively, and returns to the compressor 3-1 through port k to complete the cycle. When heating, the main electronic expansion valve 3-5 is closed, and the high-temperature and high-pressure refrigerant flow is blocked by the one-way valve 3-7 and cannot enter the rear heat recovery heat exchanger 1-4, and the rear heat recovery heat exchanger does not work.

[0029] In the solution of this embodiment, the main heat exchanger 1-3 in the heat recovery air conditioner unit 1, and the external cold and heat source device 4 is one of an air-cooled heat pump, a chilled water host, an air-cooled direct expansion machine, and a water-cooled direct expansion machine.

[0030] In the solution of this embodiment, the front heat recovery heat exchanger 1-2, the main heat exchanger 1-3, the rear heat recovery heat exchanger 1-4, and the reheater 1-5 in the heat recovery air conditioner unit 1 are finned heat exchangers.

[0031] In the solution of this embodiment, the exhaust fan 2-3 in the heat recovery exhaust fan unit 2 is one of an AC motor or a DC brushless EC motor.

[0032] In the solution of this embodiment, the supply fan 1-6 in the heat recovery air conditioner unit 1 is one of an AC motor or a DC brushless EC motor.

[0033] In the solution of this embodiment, the air inlet of the air conditioning unit 1 in the heat recovery air conditioning unit takes outdoor fresh air, indoor return air, or a mixture of fresh and return air.

[0034] In the solution of this embodiment, primary effect, medium effect, high efficiency filters or purifiers (regardless of form) are provided in the heat recovery air conditioning unit 1 according to requirements, and a humidifier (regardless of type) and other functional components can also be provided.

[0035] In the solution of this embodiment, refrigeration components such as filters, oil separators, liquid storage tanks, gas-liquid separators, etc. can be configured in the system of the heat pump device 3 according to requirements.

[0036] The present utility model is not limited to the above embodiments. Any person should know that structural changes made under the inspiration of the present utility model, as long as they have the same or similar technical solutions as the present utility model, fall within the protection scope of the present utility model.

[0037] The technologies, shapes, and structures not described in detail in the present utility model are all well-known technologies.

Claims

1. A four-element heat recovery air conditioning unit, characterized in that: It includes a heat recovery air conditioning unit, a heat recovery exhaust unit and a heat pump device. The heat recovery air conditioning unit includes an air conditioning filter, a front heat recovery heat exchanger, a main heat exchanger, a rear heat recovery heat exchanger, a reheat heat exchanger, and a blower. The heat recovery exhaust unit includes an exhaust filter, an exhaust heat recovery heat exchanger, and an exhaust fan. The heat pump device includes a compressor, a three-way valve, and a four-way reversing valve. The exhaust port of the compressor is connected to the inlet of the three-way valve, one outlet of the three-way valve is connected to the inlet of the reheat heat exchanger, the other outlet of the three-way valve is connected in parallel with the outlet of the reheat heat exchanger and then connected to the inlet of the four-way reversing valve, and a one-way valve 1 is arranged on the outlet of the reheat heat exchanger; one reversing outlet of the four-way reversing valve is connected to the inlet of the exhaust heat recovery heat exchanger, the other reversing outlet of the four-way reversing valve is connected to the pipeline in parallel with the outlets of the front heat recovery heat exchanger and the rear heat recovery heat exchanger, and a one-way valve 2 is arranged on the outlet pipeline of the rear heat recovery heat exchanger; the outlet of the four-way reversing valve is connected to the suction port of the compressor.

2. The quaternary heat recovery air conditioning unit according to claim 1, characterized in that: The outlet of the exhaust heat recovery heat exchanger is divided into two paths. One path of the outlet of the exhaust heat recovery heat exchanger is connected to the inlet of the rear heat recovery heat exchanger through the heating electronic expansion valve and the main electronic expansion valve, and the other path of the outlet of the exhaust heat recovery heat exchanger is connected to the inlet of the front heat recovery heat exchanger through the auxiliary electronic expansion valve.

3. The quaternary heat recovery air conditioning unit according to claim 2, characterized in that: The heating electronic expansion valve is connected in parallel with the check valve four, and the auxiliary electronic expansion valve is connected in parallel with the check valve three.

4. The quaternary heat recovery air conditioning unit according to claim 1, characterized in that: The heat pump device is provided with four sets of pipelines, which are respectively connected to the front heat recovery heat exchanger, the rear heat recovery heat exchanger, the reheat heat exchanger in the heat recovery air conditioning unit and the exhaust heat recovery heat exchanger in the heat recovery exhaust unit.

5. The quaternary heat recovery air conditioning unit according to claim 1, characterized in that: The main heat exchanger is connected to an external cold and heat source device through a pipeline, and the external cold and heat source device is one of an air-cooled heat pump, a cold water main unit, an air-cooled direct expansion machine, and a water-cooled direct expansion machine.

6. The quaternary heat recovery air conditioning unit according to claim 1, characterized in that: The front heat recovery heat exchanger, main heat exchanger, rear heat recovery heat exchanger, reheat heat exchanger, and exhaust heat recovery heat exchanger are all finned heat exchangers.

7. The quaternary heat recovery air conditioning unit according to claim 1, characterized in that: An air conditioning filter is installed at the air inlet of the heat recovery air conditioning unit, a blower is installed at the air outlet of the heat recovery air conditioning unit, an exhaust filter is installed at the return air outlet of the heat recovery exhaust unit, and an exhaust fan is installed at the exhaust outlet of the heat recovery exhaust unit.

8. The quaternary heat recovery air conditioning unit according to claim 7, characterized in that: The air supply fan and the exhaust fan both adopt an AC motor or a brushless DC EC motor.

9. The quaternary heat recovery air conditioning unit according to claim 7, characterized in that: The air inlet of the heat recovery air conditioning unit takes in outdoor fresh air or indoor return air or a mixture of fresh and return air.

Images