Primary air return air-conditioning system for reusing cold and heat of exhaust fresh air

Abstract

The invention discloses a one-time air return air conditioning system for conducting cold and heat recycling on exhaust fresh air. A cold circulation system comprises a compressor, a four-way valve, an exhaust heat exchanger, a first throttling valve, a second throttling valve, a fresh air heat exchanger, a reheating heat exchanger, a third throttling valve and an outdoor heat exchanger. The air circulation system comprises an air exhaust adjusting valve, an air return adjusting valve, a fresh air adjusting valve, an air exhaust fan, a heat exchange coil, a humidifier and an air supply fan. The air conditioner has the beneficial effects that in summer, cooling capacity in exhaust air can be recycled to conduct heat removal and dehumidification on fresh air, heat in the fresh air and heat in outdoor air are recycled to conduct secondary heating on supplied air, and in winter, heat in the exhaust air and heat in the outdoor air can be recycled to conduct heating on the fresh air and secondary heating on the supplied air; the requirement for the air supply cooling capacity is reduced, meanwhile, the energy consumption loss caused by cold and heat offset of a conventional primary air return air conditioning system is reduced, the air treatment process of the primary air return air conditioning system is optimized, and the energy consumption of the primary air return air conditioning system is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of building air conditioning and heating energy, and in particular to a primary return air conditioning system for recycling the cooling and heating of exhaust fresh air. Background Art

[0002] Air conditioning consumes a lot of energy in buildings, accounting for 50% to 70% of the total energy consumption. Therefore, it is very necessary to take energy-saving measures for the air conditioning system of the building. The proportion of air conditioning energy consumption in building energy consumption has always been high. The traditional central air conditioning system mixes outdoor fresh air and indoor return air for heat and humidity treatment, and then supplies air to the building to eliminate the load in the building. Among them, the fresh air load, as one of the components of the air conditioning load, generally accounts for 30% to 50% of the air conditioning load, and even exceeds 60% in winter, and even exceeds 70% in public buildings with a large population density. The use of exhaust heat recovery devices in the air conditioning system can recover and utilize the cold / heat contained in the exhaust air, pre-treat the fresh air, and thus reduce the energy consumption generated by processing the fresh air. Studies have shown that when the heat recovery efficiency of the heat recovery device reaches 70%, it can effectively reduce the heating energy consumption by 40% to 50%.

[0003] The most widely used air-conditioning system at present is the single-return air-conditioning system. The single-return air-conditioning system is an air-conditioning system that fully mixes the indoor return air and the outdoor fresh air during the centralized air processing process. The mixed air is then cooled by the surface cooler and then directly sent to the air-conditioned room or sent to the return air of the air-conditioned room after heating.

[0004] Under refrigeration conditions, in order to remove water vapor from the air, the evaporation temperature of the refrigerant in the traditional central air-conditioning system needs to be much lower than the dew point temperature of the air, which increases the temperature difference between the evaporation temperature and the condensation temperature of the refrigeration unit. The lower evaporation temperature reduces the performance coefficient of the refrigerant group to a certain extent. At the same time, under the dew point air supply state, the indoor temperature and humidity parameters may deviate from the design operating point, and the reheat air supply will consume more energy; and the temperature and humidity of the air are coupled in the surface cooling treatment, which does not really bring into play the energy efficiency of the cold source, which is not conducive to the subsequent operation and regulation. In the single return air handling unit, the mixed air is cooled and dehumidified by the surface cooler and then reheated by the reheater. This process of cooling and reheating is called "cold and hot offset", which causes a lot of energy waste.

[0005] The secondary return air system, which was created to address the drawback of the primary return air system, saves the extra energy applied by the reheater, but at the cost of lowering the dew point of the machine. As a result, on the one hand, the operating efficiency of the refrigeration system is reduced, and on the other hand, the use of natural cooling sources is further restricted. At the same time, the secondary return air system is also restricted in its use due to its poor anti-humidity ability and the inconvenience of adjustment and control.

[0006] Traditional central air-conditioning systems have numerous loops and complex systems. The energy consumption during the energy transmission process of each loop is huge, almost equivalent to the energy consumption of the cold and heat sources, resulting in a significant reduction in the performance coefficient of the entire air-conditioning system.

[0007] Therefore, in order to solve the above problems, it is necessary to propose a single return air conditioning system that utilizes the heat of fresh air for reheating. Summary of the invention

[0008] The purpose of the present invention is to provide a single return air air conditioning system that utilizes the heat of fresh air for reheating, and to add a heat pump refrigerant circulation device to the conventional single return air air conditioning system to optimize the air treatment process of the single return air air conditioning system, and to innovatively integrate the heat pump combined cooling and heat supply with the different treatment processes of fresh air, exhaust air and supply air of the single return air air conditioning system, so as to solve the problem proposed in the above background technology that in the single return air handling unit, the mixed air is cooled and dehumidified by the surface cooler and then reheated by the reheater. This process of reheating after cooling is called "cold and heat offset", which causes a lot of energy waste.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A single return air conditioning system for recycling the heat and cold of exhaust fresh air, comprising a cold circulation system and an air circulation system, characterized in that: the cold circulation system comprises a compressor, a four-way valve, an exhaust air heat exchanger, a first throttle valve, a second throttle valve, a fresh air heat exchanger, a reheat heat exchanger, a third throttle valve, and an outdoor heat exchanger;

[0011] A compressor, the compressor comprising an exhaust port disposed at one end of the compressor and an intake port disposed at the other end of the compressor; a four-way valve, the four-way valve being disposed outside the compressor;

[0012] A four-way valve consists of four groups of ports, “a,” “b,” “c,” and “d”;

[0013] An exhaust heat exchanger, which is arranged outside the compressor and is used for subsequent heat exchange of the exhaust air entering from the exhaust port of the air cabinet of the air conditioner;

[0014] a first throttle valve, the first throttle valve being arranged outside the exhaust air heat exchanger;

[0015] a second throttle valve, the second throttle valve being arranged outside the first throttle valve;

[0016] A fresh air heat exchanger, which is arranged outside the second throttle valve and is used for subsequent heat exchange of the fresh air entering from the fresh air outlet of the air conditioner;

[0017] A reheat heat exchanger, which is arranged outside the compressor and is used for subsequent reheat exchange of the supply air entering the reheat section of the air cabinet of the air conditioner;

[0018] a third throttle valve, the third throttle valve being arranged outside the reheat heat exchanger,

[0019] An outdoor heat exchanger, which is arranged outside the compressor and is used for evaporation and heat absorption of the liquid working medium after being throttled by the third throttle valve;

[0020] The air circulation system includes an exhaust air regulating valve, a return air regulating valve, a fresh air regulating valve, an exhaust air fan, a heat exchange coil, a humidifier, and an air supply fan;

[0021] An exhaust regulating valve, which is arranged outside the exhaust heat exchanger and is used to control the return air at the return air section of a part of the air conditioner cabinet to pass through the exhaust heat exchanger for heat exchange;

[0022] A return air regulating valve, which is arranged outside the exhaust air regulating valve and is used to control the return air at the return air section of another part of the air conditioner cabinet to pass to the mixing section of the air conditioner cabinet;

[0023] A fresh air regulating valve is arranged on the outside of the fresh air heat exchanger, and is used to control the fresh air at the fresh air section of the air conditioner to pass to the mixing section of the air conditioner.

[0024] Preferably, the cold circulation system further comprises:

[0025] a first pipeline, wherein two ends of the first pipeline are respectively connected to the exhaust port and the "a" port of the four-way valve;

[0026] A second pipeline, both ends of which are respectively connected to one end of the exhaust heat exchanger and a "b" port of the four-way valve;

[0027] A third pipeline, two ends of which are respectively connected to the other end of the exhaust heat exchanger and one end of the first throttle valve;

[0028] a fourth pipeline, two ends of which are respectively connected to the other end of the first throttle valve and one end of the second throttle valve;

[0029] a fifth pipeline, wherein two ends of the fifth pipeline are respectively connected to the other end of the second throttle valve and one end of the fresh air heat exchanger;

[0030] a sixth pipeline, wherein both ends of the sixth pipeline are respectively connected to the other end of the fresh air heat exchanger and the "d" port of the four-way valve;

[0031] a seventh pipeline, two ends of which are respectively connected to the "c" port of the four-way valve and the air inlet;

[0032] an eighth pipeline, one end of the eighth pipeline being connected to the pipe body of the first pipeline, and the other end of the eighth pipeline being connected to the reheat heat exchanger;

[0033] a ninth pipeline, one end of which is connected to the other end of the reheat heat exchanger, and the other end of which is connected to the pipe body of the fourth pipeline;

[0034] a tenth pipeline, one end of which is connected to the ninth pipeline, and the other end of which is connected to one end of the third throttle valve;

[0035] an eleventh pipeline, one end of the eleventh pipeline being connected to the other end of the third throttle valve, and the other end of the eleventh pipeline being connected to the outdoor heat exchanger;

[0036] The twelfth pipeline has two ends connected to the C end of the compressor and the outdoor heat exchanger respectively.

[0037] Preferably, the wind circulation system also includes

[0038] An exhaust fan, the exhaust fan is arranged outside the exhaust heat exchanger, and the exhaust fan is used to exhaust part of the return air to the outdoor environment;

[0039] A heat exchange coil, wherein the heat exchange coil is arranged outside the return air regulating valve and the fresh air regulating valve;

[0040] A humidifier, wherein the humidifier is arranged outside the reheat heat exchanger;

[0041] The air supply fan is arranged on the outside of the humidifier.

[0042] Preferably, when the exhaust air heat exchanger and the reheat heat exchanger are condensers, the fresh air heat exchanger and the outdoor heat exchanger are evaporators.

[0043] Preferably, when the fresh air heat exchanger and the reheat heat exchanger are condensers, the exhaust air heat exchanger and the outdoor heat exchanger are evaporators.

[0044] Preferably, the first throttle valve, the second throttle valve and the third throttle valve are preferably solenoid valves when they have a throttling effect.

[0045] Preferably, the exhaust air heat exchanger, fresh air heat exchanger, and reheat heat exchanger equipment can be circulating coils such as external cold and hot source water, heat pipe working fluid, and heat transfer oil to indirectly exchange heat with the air, or can be refrigerant circulation equipment to directly exchange heat with the air. Preferably, the refrigerant circulation equipment can directly exchange heat with the air.

[0046] Preferably, the exhaust fan is an equipment inside the air conditioning cabinet or a fan of an external exhaust duct; the supply air fan is an equipment inside the air conditioning cabinet or a fan of an external supply air duct. Under winter conditions, the heat exchange coil may exist as a heat source or may not exist as a heat source; the humidifier may be located after the reheat heat exchanger, or may be located at other positions in the air conditioning cabinet depending on the humidification method, such as isothermal or isenthalpic.

[0047] In summary, the present invention has the following beneficial effects: by providing a compressor, a four-way valve, an exhaust air heat exchanger, a first throttle valve, a second throttle valve, a third throttle valve, a fresh air heat exchanger, a reheat heat exchanger, an outdoor heat exchanger, an exhaust air regulating valve, a return air regulating valve, a fresh air regulating valve, an exhaust fan, a heat exchange coil, a humidifier and a supply air fan; the single return air air conditioning system for recycling the heat of the exhaust fresh air can meet the needs of exhaust air heat recovery, fresh air heat treatment and supply air secondary heating under various working conditions, and in summer, the cold energy in the exhaust air can be recovered to remove heat and humidify the fresh air, and the heat in the fresh air and the outdoor air can be recovered to heat the supply air. The secondary air heating reduces the demand for supply air cooling and the energy loss caused by the heat offset of the conventional single-return air conditioning system. In winter, the heat in the exhaust air and the outdoor air can be recovered to heat the fresh air and to perform secondary heating on the supply air. The system can recover the heat of the exhaust air, perform heat treatment on the fresh air and perform secondary heating on the supply air under winter and summer working conditions, thus avoiding the energy consumption of the conventional single-return air conditioning system using electric heating. The heat recovery amount is well adjustable, which well optimizes the air treatment process of the conventional single-return air conditioning system and greatly reduces the energy consumption of the conventional single-return air conditioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the structural principle of the present invention.

[0049] 10. The accompanying drawings are as follows: 1. compressor; 101. exhaust port; 102. intake port; 2. four-way valve; 3. exhaust heat exchanger; 4. first throttle valve; 5. second throttle valve; 6. fresh air heat exchanger; 7. reheat heat exchanger; 8. exhaust air regulating valve; 9. return air regulating valve; 10. fresh air regulating valve; 11. exhaust fan; 12. heat exchange coil; 13. humidifier; 14. supply air fan; 15. first pipeline; 16. second pipeline; 17. third pipeline; 18. fourth pipeline; 19. fifth pipeline; 20. sixth pipeline; 21. seventh pipeline; 22. eighth pipeline; 23. ninth pipeline; 24. tenth pipeline; 25. eleventh pipeline; 26. twelfth pipeline; 27. third throttle valve; 28. outdoor heat exchanger. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The following is combined with Figure 1 The embodiments of the present invention are described in further detail.

[0052] like Figure 1 As shown, this embodiment provides a technical solution: a single return air conditioning system for recycling the heat and cold of exhaust fresh air, including a cold circulation system and an air circulation system, characterized in that: the cold circulation system includes a compressor 1, a four-way valve 2, an exhaust air heat exchanger 3, a first throttle valve 4, a second throttle valve 5, a fresh air heat exchanger 6, a reheat heat exchanger 7, a third throttle valve 27, and an outdoor heat exchanger 28;

[0053] A compressor 1, wherein the compressor 1 comprises an exhaust port 101 arranged at one end of the compressor 1 and an intake port 102 arranged at the other end of the compressor 1; a four-way valve 2, wherein the four-way valve 2 is arranged outside the compressor 1;

[0054] The four-way valve 2 consists of four groups of ports, "a", "b", "c" and "d";

[0055] An exhaust heat exchanger 3, which is arranged outside the compressor 1 and is used for subsequent heat exchange of the exhaust air entering from the exhaust port of the air conditioner;

[0056] A first throttle valve 4, wherein the first throttle valve 4 is arranged outside the exhaust air heat exchanger 3;

[0057] A second throttle valve 5, wherein the second throttle valve 5 is arranged outside the first throttle valve 4;

[0058] A fresh air heat exchanger 6, which is arranged outside the second throttle valve 5 and is used for subsequent heat exchange of the fresh air entering from the fresh air outlet of the air conditioner;

[0059] A reheat heat exchanger 7, which is arranged outside the compressor 1 and is used for subsequent reheat exchange of the supply air entering the reheat section of the air cabinet of the air conditioner;

[0060] The third throttle valve 27 is arranged outside the reheat heat exchanger 7.

[0061] An outdoor heat exchanger 28, which is arranged outside the compressor 1 and is used for evaporation and heat absorption of the liquid working medium after being throttled by the third throttle valve 27;

[0062] The air circulation system includes an exhaust air regulating valve 8, a return air regulating valve 9, a fresh air regulating valve 10, an exhaust air fan 11, a heat exchange coil 12, a humidifier 13, and an air supply fan 14;

[0063] An exhaust regulating valve 8, which is arranged outside the exhaust heat exchanger 3, and is used to control the return air at the return air section of a part of the air conditioner to pass through the exhaust heat exchanger 3 for heat exchange;

[0064] A return air regulating valve 9, which is arranged outside the exhaust air regulating valve 8 and is used to control the return air at the return air section of another part of the air conditioner to pass to the mixing section of the air conditioner;

[0065] The fresh air regulating valve 10 is arranged on the outside of the fresh air heat exchanger 6, and the fresh air regulating valve 10 is used to control the fresh air at the fresh air section of the air conditioner to pass to the mixing section of the air conditioner.

[0066] Preferably, the cold circulation system further comprises:

[0067] A first pipeline 15, two ends of which are respectively connected to the exhaust port 101 and the "a" port of the four-way valve 2;

[0068] A second pipeline 16, both ends of which are respectively connected to one end of the exhaust heat exchanger 3 and the "b" port of the four-way valve 2;

[0069] A third pipeline 17, two ends of which are respectively connected to the other end of the exhaust heat exchanger 3 and one end of the first throttle valve 4;

[0070] a fourth pipeline 18, two ends of which are respectively connected to the other end of the first throttle valve 4 and one end of the second throttle valve 5;

[0071] A fifth pipeline 19, two ends of which are respectively connected to the other end of the second throttle valve 5 and one end of the fresh air heat exchanger 6;

[0072] A sixth pipeline 20, two ends of which are respectively connected to the other end of the fresh air heat exchanger 6 and the "d" port of the four-way valve 2;

[0073] A seventh pipeline 21, two ends of which are respectively connected to the "c" port of the four-way valve 2 and the air inlet 102;

[0074] An eighth pipeline 22, one end of the eighth pipeline 22 is connected to the pipe body of the first pipeline 15, and the other end of the eighth pipeline 22 is connected to the reheat heat exchanger 7;

[0075] A ninth pipeline 23, one end of the ninth pipeline 23 is connected to the other end of the reheat heat exchanger 7, and the other end of the ninth pipeline 23 is connected to the pipe body of the fourth pipeline 18;

[0076] a tenth pipeline 24, one end of which is connected to the ninth pipeline 23, and the other end of which is connected to one end of the third throttle valve 27;

[0077] An eleventh pipeline 25, one end of the eleventh pipeline 25 is connected to the other end of the third throttle valve 27, and the other end of the eleventh pipeline 25 is connected to the outdoor heat exchanger 28;

[0078] The twelfth pipeline 26 has two ends connected to the C end of the compressor 1 and the outdoor heat exchanger 28 respectively.

[0079] Preferably, the wind circulation system also includes

[0080] An exhaust fan 11, which is arranged outside the exhaust heat exchanger 3 and is used to exhaust part of the return air to the outdoor environment;

[0081] The heat exchange coil 12 is arranged outside the return air regulating valve 9 and the fresh air regulating valve 10, and the heat exchange coil 12 is connected to an external cold and heat source;

[0082] A humidifier 13, wherein the humidifier 13 is arranged outside the reheat heat exchanger 7, and the humidifier 13 is externally connected to a humidifier water supply pipe;

[0083] The air supply fan 14 is arranged outside the humidifier 13 .

[0084] Preferably, when the exhaust air heat exchanger 3 and the reheat heat exchanger 7 are condensers, the fresh air heat exchanger 6 and the outdoor heat exchanger 28 are evaporators.

[0085] Preferably, when the fresh air heat exchanger 6 and the reheat heat exchanger 7 are condensers, the exhaust air heat exchanger 3 and the outdoor heat exchanger 28 are evaporators.

[0086] Preferably, the first throttle valve 4, the second throttle valve 7 and the third throttle valve 27 are preferably solenoid valves when they have a throttling effect.

[0087] Preferably, the exhaust air heat exchanger 3, the fresh air heat exchanger 6, and the reheat heat exchanger 7 can be circulating coils such as external cold or hot source water, heat pipe working fluid, heat transfer oil, etc., which can indirectly exchange heat with the air, or can be refrigerant circulation equipment that directly exchanges heat with the air. Preferably, the refrigerant circulation equipment directly exchanges heat with the air.

[0088] Preferably, the exhaust fan 11 is an internal device of the air conditioning cabinet or a fan of an external exhaust pipe; the supply fan 14 is an internal device of the air conditioning cabinet or a fan of an external supply pipe. Under winter conditions, the heat exchange coil 12 may exist as a heat source or may not exist as a heat source; the humidifier 13 may be located after the reheat heat exchanger 7, or may be located at other positions of the air conditioning cabinet according to different humidification methods, such as isothermal and isenthalpic.

[0089] In summary, the present invention includes the following beneficial effects: by providing a compressor, a four-way valve, an exhaust heat exchanger, a first throttle valve, a second throttle valve, a third throttle valve, a fresh air heat exchanger, a reheat heat exchanger, an outdoor heat exchanger, an exhaust regulating valve, a return air regulating valve, a fresh air regulating valve, an exhaust fan, a heat exchange coil, a humidifier and a supply air fan; the single return air air conditioning system for recycling the heat of the exhaust fresh air can meet the needs of exhaust heat recovery, fresh air heat treatment and supply air secondary heating under various working conditions; in summer, the cold energy in the exhaust air can be recovered to deheat and dehumidify the fresh air, and the heat in the fresh air and the outdoor air can be recovered to perform secondary heating of the supply air, which reduces the demand for supply air cooling and reduces the energy consumption loss caused by the cold and heat offset of the conventional single return air air conditioning system; in winter, the heat in the exhaust air and the outdoor air can be recovered to heat the fresh air and perform secondary heating of the supply air. The system can recover the heat and cold of the exhaust air, perform heat and cold treatment on the fresh air, and perform secondary heating on the supply air under winter and summer working conditions, thus avoiding the energy consumption of electric heating in conventional single-return air conditioning systems. The heat and cold recovery amount is highly adjustable, which greatly optimizes the air treatment process of conventional single-return air conditioning systems and greatly reduces the energy consumption of conventional single-return air conditioning systems.

[0090] In the present invention, under summer working conditions, when the exhaust air heat exchanger and the reheat heat exchanger are condensers, the fresh air heat exchanger and the outdoor heat exchanger are evaporators.

[0091] In the present invention, under winter working conditions, when the fresh air heat exchanger and the reheat heat exchanger are condensers, the exhaust air heat exchanger and the outdoor heat exchanger are evaporators.

[0092] Use Example 1

[0093] Under summer conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust fresh air as a summer refrigeration cycle to achieve exhaust air cooling recovery only:

[0094] The refrigerant cycle of the system is as follows: the first throttle valve 4 is opened and the third throttle valve 8 is closed; the exhaust gas of the compressor 1 flows through the a end of the four-way valve 2 and the b end of the four-way valve 2 to the exhaust air heat exchanger 3 to condense and release heat; the liquid working medium passes through the first throttle valve 4 and is throttled by the second throttle valve 5 to evaporate and absorb heat in the fresh air heat exchanger 6; the gaseous working medium flows through the d end of the four-way valve 2 and the c end of the four-way valve 2 and then returns to the compressor 1.

[0095] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0096] Use Example 2

[0097] Under summer conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust fresh air as a summer refrigeration cycle to achieve only outdoor heat extraction and secondary heating of the supply air:

[0098] The refrigerant cycle of the system is as follows: the first throttle valve 4 is closed, the second throttle valve 5 is closed, the exhaust gas of the compressor 1 is condensed and releases heat in the reheat heat exchanger 7, the liquid working medium is throttled by the third throttle valve 8 and evaporates and absorbs heat in the outdoor heat exchanger 9, and the gaseous working medium flows through the pipeline back to the compressor 1.

[0099] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0100] Use Example 3

[0101] Under summer conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust air as a summer refrigeration cycle, which simultaneously does not recycle the exhaust air cooling capacity, recycles the fresh air heat, does not take heat from the outside, and performs secondary heating on the supply air:

[0102] The refrigerant cycle of the system is as follows: the first throttle valve 4 is closed, the third throttle valve 8 is closed, the exhaust gas of the compressor 1 is condensed and releases heat in the reheat heat exchanger 7, the liquid working medium is throttled by the second throttle valve 5 and then evaporates and absorbs heat in the fresh air heat exchanger 6, and the gaseous working medium flows through the d end of the four-way valve 2 and the c end of the four-way valve 2 and then returns to the compressor 1.

[0103] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0104] Use Example 4

[0105] In summer conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust air and fresh air as a summer refrigeration cycle to realize simultaneous exhaust air cooling recovery, fresh air heat recovery, no outdoor heat extraction, and secondary heating of the supply air:

[0106] The refrigerant cycle of the system is as follows: the first throttle valve 4 is opened, the third throttle valve 8 is closed, the exhaust gas of the compressor 1 flows through the a end of the four-way valve 2 and the b end of the four-way valve 2 to the exhaust heat exchanger 3 for condensation and heat release, and the other way flows to the reheat heat exchanger 7 for condensation and heat release, the liquid working medium flowing out of the exhaust heat exchanger 3 passes through the first throttle valve 4 and is mixed with the liquid working medium flowing out of the reheat heat exchanger 7, and then is throttled by the second throttle valve 5 to evaporate and absorb heat in the fresh air heat exchanger 6, and the gaseous working medium flows through the d end of the four-way valve 2 and the c end of the four-way valve 2 and then returns to the compressor 1.

[0107] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0108] Use Example 5

[0109] Under summer conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust air and fresh air as a summer refrigeration cycle to simultaneously recover the exhaust air cooling capacity, recover the fresh air heat, and extract outdoor heat, and perform secondary heating on the supply air:

[0110] The refrigerant cycle of the system is as follows: the first throttle valve 4 is opened, and the exhaust gas of the compressor 1 flows through the a end of the four-way valve 2 and the b end of the four-way valve 2 to the exhaust heat exchanger 3 for condensation and heat release, and flows through the other end to the reheat heat exchanger 7 for condensation and heat release. The liquid working medium flowing out of the exhaust heat exchanger 3 passes through the first throttle valve 4 and is mixed with the liquid working medium flowing out of the reheat heat exchanger 7. A part of the liquid working medium is throttled by the second throttle valve 5 and evaporates and absorbs heat in the fresh air heat exchanger 6. The gaseous working medium flows through the d end of the four-way valve 2 and the c end of the four-way valve 2 and then returns to the compressor 1. The other part of the liquid working medium is throttled by the third throttle valve 8 and evaporates and absorbs heat in the outdoor heat exchanger 9. The gaseous working medium flows through the pipeline and returns to the compressor 1.

[0111] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0112] Use Example 6

[0113] Under winter conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust air as a winter heating cycle to achieve exhaust heat recovery only:

[0114] The refrigerant cycle of the system is as follows: the second throttle valve 5 is opened and the third throttle valve 8 is closed; the exhaust gas of the compressor 1 flows through the a end of the four-way valve 2 and the d end of the four-way valve 2 to the fresh air heat exchanger 6 to condense and release heat; the liquid working medium passes through the second throttle valve 5 and is throttled by the first throttle valve 4 to evaporate and absorb heat in the exhaust air heat exchanger 3; the gaseous working medium flows through the b end of the four-way valve 2 and the c end of the four-way valve 2 and then returns to the compressor 1.

[0115] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0116] Use Example 7

[0117] Under winter conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust fresh air as a winter heating cycle to achieve only outdoor heat extraction and secondary heating of the supply air:

[0118] The refrigerant cycle of the system is as follows: the first throttle valve 4 is closed, the second throttle valve 5 is closed, the exhaust gas of the compressor 1 is condensed and releases heat in the reheat heat exchanger 7, the liquid working medium is throttled by the third throttle valve 8 and evaporates and absorbs heat in the outdoor heat exchanger 9, and the gaseous working medium flows through the pipeline back to the compressor 1.

[0119] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0120] Use Example 8

[0121] Under winter conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust air and fresh air as a winter heating cycle to achieve the conditions of no exhaust heat recovery, fresh air heating, outdoor heat extraction, and secondary heating of supply air:

[0122] The refrigerant cycle of the system is as follows: the first throttle valve 4 is closed and the second throttle valve 5 is opened, the exhaust gas of the compressor 1 flows through the a end of the four-way valve 2 and the d end of the four-way valve 2 to the fresh air heat exchanger 6 to condense and release heat, and the other way flows to the reheat heat exchanger 7 to condense and release heat, the liquid working medium flowing out of the fresh air heat exchanger 6 passes through the second throttle valve 5 and is mixed with the liquid working medium flowing out of the reheat heat exchanger 7, and then is throttled by the third throttle valve 8 to evaporate and absorb heat in the outdoor heat exchanger 9, and the gaseous working medium flows through the pipeline back to the compressor 1.

[0123] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0124] Use Example 9

[0125] Under winter conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust air and fresh air as a winter heating cycle to simultaneously recover the heat of exhaust air, heat fresh air, and not take heat from the outside, and perform secondary heating on the supply air:

[0126] The refrigerant cycle of the system is as follows: the second throttle valve 5 is opened, the third throttle valve 8 is closed, the exhaust gas of the compressor 1 flows through the a end of the four-way valve 2 and the d end of the four-way valve 2 to the fresh air heat exchanger 6 for condensation and heat release, and the other way flows to the reheat heat exchanger 7 for condensation and heat release, the liquid working medium flowing out of the fresh air heat exchanger 6 passes through the second throttle valve 5 and is mixed with the liquid working medium flowing out of the reheat heat exchanger 7, and then is throttled by the first throttle valve 4 to evaporate and absorb heat in the exhaust air heat exchanger 3, and the gaseous working medium flows through the b end of the four-way valve 2 and the c end of the four-way valve 2 and then returns to the compressor 1.

[0127] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0128] Use Example 10

[0129] Under winter conditions, the present invention provides a single return air conditioning system for recycling the heat of exhaust air and fresh air as a winter heating cycle to simultaneously recover exhaust air heat, heat fresh air, and take heat from the outdoors, and to perform secondary heating on the supply air:

[0130] The refrigerant cycle of the system is as follows: the second throttle valve 5 is opened, and the exhaust gas of the compressor 1 flows through the a end of the four-way valve 2 and the d end of the four-way valve 2 to the fresh air heat exchanger 6 for condensation and heat release, and flows through the other end to the reheat heat exchanger 7 for condensation and heat release. The liquid working medium flowing out of the fresh air heat exchanger 6 passes through the second throttle valve 5 and is mixed with the liquid working medium flowing out of the reheat heat exchanger 7. A part of the liquid is throttled by the first throttle valve 4 and evaporates and absorbs heat in the exhaust air heat exchanger 3. The gaseous working medium flows through the b end of the four-way valve 2 and the c end of the four-way valve 2 and then returns to the compressor 1. The other part of the liquid working medium is throttled by the third throttle valve 8 and evaporates and absorbs heat in the outdoor heat exchanger 9. The gaseous working medium flows through the pipeline and returns to the compressor 1.

[0131] The air circulation of the system is as follows: after the return air in the air-conditioned room enters through the return air outlet of the air-conditioning air cabinet, a part of it enters the exhaust passage through the exhaust air regulating valve 8 and exchanges heat with the exhaust air heat exchanger 3, and is then discharged to the outdoor environment by the exhaust fan 11; the other part enters the mixing section of the air-conditioning air cabinet through the return air regulating valve 9 and is mixed with the fresh air entering through the fresh air regulating valve 10. Before the fresh air enters the mixing section of the air-conditioning air cabinet, it first enters through the fresh air outlet of the air-conditioning air cabinet and completes heat exchange with the fresh air heat exchanger 6; the mixed air passes through the heat exchange coil 12, the reheat heat exchanger 7, and the humidifier 13 to complete heat and humidity treatment in sequence, and is then sent into the air-conditioned room through the supply air fan 14.

[0132] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A primary return air conditioning system for recycling exhaust fresh air, comprising a cold circulation system and an air circulation system, characterized in that: The cold circulation system comprises a compressor (1), a four-way valve (2), an exhaust air heat exchanger (3), a first throttle valve (4), a second throttle valve (5), a fresh air heat exchanger (6), a reheat heat exchanger (7), a third throttle valve (27), and an outdoor heat exchanger (28); A compressor (1), the compressor (1) comprising an exhaust port (101) arranged at one end of the compressor (1) and an intake port (102) arranged at the other end of the compressor (1); a four-way valve (2), the four-way valve (2) being arranged outside the compressor (1); The four-way valve (2) consists of four groups of ports, "a", "b", "c" and "d"; An exhaust heat exchanger (3), the exhaust heat exchanger (3) being arranged outside the compressor (1), and the exhaust heat exchanger (3) being used for subsequent heat exchange of exhaust air entering from the exhaust port of the air cabinet of the air conditioner; A first throttle valve (4), the first throttle valve (4) being arranged outside the exhaust air heat exchanger (3); A second throttle valve (5), the second throttle valve (5) being arranged outside the first throttle valve (4); A fresh air heat exchanger (6), the fresh air heat exchanger (6) being arranged outside the second throttle valve (5), the fresh air heat exchanger (6) being used for subsequent heat exchange of the fresh air entering from the fresh air outlet of the air conditioner; A reheat heat exchanger (7), the reheat heat exchanger (7) being arranged outside the compressor (1), the reheat heat exchanger (7) being used for subsequent reheat exchange of the supply air entering the reheat section of the air cabinet of the air conditioner; a third throttle valve (27), the third throttle valve (27) being arranged outside the reheat heat exchanger (7), An outdoor heat exchanger (28), the outdoor heat exchanger (28) being arranged outside the compressor (1) and used for evaporating and absorbing heat the liquid working medium after being throttled by the third throttle valve (27); The air circulation system comprises an exhaust air regulating valve (8), a return air regulating valve (9), a fresh air regulating valve (10), an exhaust air fan (11), a heat exchange coil (12), a humidifier (13), and an air supply fan (14).

2. A primary return air conditioning system for recycling exhaust air and fresh air as claimed in claim 1, characterized in that: The cold circulation system also includes: A first pipeline (15), wherein two ends of the first pipeline (15) are respectively connected to the exhaust port (101) and the "a" port of the four-way valve (2); A second pipeline (16), the two ends of which are respectively connected to one end of the exhaust heat exchanger (3) and the "b" port of the four-way valve (2); A third pipeline (17), wherein two ends of the third pipeline (17) are respectively connected to the other end of the exhaust heat exchanger (3) and one end of the first throttle valve (4); a fourth pipeline (18), wherein two ends of the fourth pipeline (18) are respectively connected to the other end of the first throttle valve (4) and one end of the second throttle valve (5); A fifth pipeline (19), the two ends of which are respectively connected to the other end of the second throttle valve (5) and one end of the fresh air heat exchanger (6); A sixth pipeline (20), wherein two ends of the sixth pipeline (20) are respectively connected to the other end of the fresh air heat exchanger (6) and the "d" port of the four-way valve (2); A seventh pipeline (21), wherein two ends of the seventh pipeline (21) are respectively connected to the "c" port of the four-way valve (2) and the air intake port (102); an eighth pipeline (22), one end of the eighth pipeline (22) being connected to the pipe body of the first pipeline (15), and the other end of the eighth pipeline (22) being connected to the reheat heat exchanger (7); a ninth pipeline (23), one end of the ninth pipeline (23) being connected to the other end of the reheat heat exchanger (7), and the other end of the ninth pipeline (23) being connected to the pipe body of the fourth pipeline (18); a tenth pipeline (24), one end of the tenth pipeline (24) being connected to the ninth pipeline (23), and the other end of the tenth pipeline (24) being connected to one end of the third throttle valve (27); an eleventh pipeline (25), one end of the eleventh pipeline (25) being connected to the other end of the third throttle valve (27), and the other end of the eleventh pipeline (25) being connected to an outdoor heat exchanger (28); A twelfth pipeline (26), the two ends of which are respectively connected to the C end of the compressor (1) and the outdoor heat exchanger (28).

3. A primary return air conditioning system for recycling exhaust fresh air for cooling and heating as described in any one of claims 1-2, characterized in that: The wind circulation system also includes An exhaust regulating valve (8), the exhaust regulating valve (8) being arranged outside the exhaust heat exchanger (3), the exhaust regulating valve (8) being used to control the return air at a part of the return air section of the air cabinet of the air conditioner to pass through the exhaust heat exchanger (3) for heat exchange; A return air regulating valve (9), the return air regulating valve (9) being arranged outside the exhaust air regulating valve (8), the return air regulating valve (9) being used to control the return air at the return air section of another part of the air conditioner cabinet to pass to the mixing section of the air conditioner cabinet; A fresh air regulating valve (10), the fresh air regulating valve (10) being arranged on the outside of the fresh air heat exchanger (6), the fresh air regulating valve (10) being used to control the fresh air at the fresh air section of the air conditioner to pass to the mixing section of the air conditioner; An exhaust fan (11), the exhaust fan (11) being arranged outside the exhaust heat exchanger (3), and the exhaust fan (11) being used to exhaust part of the return air into the outdoor environment; A heat exchange coil (12), wherein the heat exchange coil (12) is arranged outside the return air regulating valve (9) and the fresh air regulating valve (10); a humidifier (13), wherein the humidifier (13) is arranged outside the reheat heat exchanger (7); An air supply fan (14), wherein the air supply fan (14) is arranged outside the humidifier (13).

4. A primary return air conditioning system for recycling exhaust fresh air for cooling and heating according to any one of claims 1 to 3, characterized in that: When the exhaust air heat exchanger (3) and the reheat heat exchanger (7) are condensers, the fresh air heat exchanger (6) and the outdoor heat exchanger (28) are evaporators.

5. A primary return air conditioning system for recycling exhaust air and fresh air according to any one of claims 1 to 3, characterized in that: When the fresh air heat exchanger (6) and the reheat heat exchanger (7) are condensers, the exhaust air heat exchanger (3) and the outdoor heat exchanger (28) are evaporators.

6. A primary return air conditioning system for recycling exhaust fresh air for cooling and heating according to any one of claims 1 to 3, characterized in that: The first throttle valve (4), the second throttle valve (7) and the third throttle valve (27) are preferably solenoid valves when they have a throttling effect.

7. A primary return air conditioning system for recycling exhaust fresh air for cooling and heating according to any one of claims 1 to 3, characterized in that: The exhaust air heat exchanger (3), the fresh air heat exchanger (6), and the reheat heat exchanger (7) can be external cold and heat source circulation coils for indirect heat exchange with the air, or can be refrigerant circulation equipment for direct heat exchange with the air, preferably, refrigerant circulation equipment for direct heat exchange with the air.

8. A primary return air conditioning system for recycling exhaust fresh air for cooling and heating according to any one of claims 1 to 3, characterized in that: The exhaust fan (11) is a device inside the air conditioning cabinet or a fan of an external exhaust pipe; the supply fan (14) is a device inside the air conditioning cabinet or a fan of an external supply pipe.

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