Condensation heat cascade recovery efficient refrigerating system

Abstract

The invention discloses a condensation heat cascade recovery efficient refrigerating system, which belongs to the technical field of energy conservation of central air conditioners and comprises a heat recovery unit, an exhaust unit and a fresh air unit, the heat recovery unit, the exhaust unit and the fresh air unit are sequentially and hermetically assembled, and the upper end of the exhaust unit is communicated with the heat recovery unit. Exhaust air can enter the heat recovery unit for primary heat exchange, fresh air can enter the fresh air unit for precooling, a condensation heat recovery mechanism is arranged at the bottom of the exhaust unit, and the condensation heat recovery mechanism can conduct secondary heat exchange on the exhaust air obtained after primary heat exchange. The condensation heat recovery mechanism can absorb heat generated after fresh air is precooled, and the fresh air handling unit can adjust the humidity of the fresh air side through condensate water. According to the invention, the exhaust air subjected to primary heat exchange is subjected to secondary heat exchange through the condensation heat recovery mechanism, so that the heat transfer temperature difference is increased, and the heat transfer efficiency of the condensation heat recovery mechanism is improved; the fresh air side humidity can be adjusted through condensate water, and the energy utilization efficiency is improved.

Description

Technical Field

[0001] The invention relates to a high-efficiency refrigeration system for step-by-step recovery of condensation heat, belonging to the technical field of energy saving of central air conditioners. Background Art

[0002] Air conditioning equipment can provide processed air to a designated space, ensuring that the air in the designated space maintains the specified temperature, humidity, and controls dust and harmful gas content. Central air conditioning is a type of air conditioning equipment. Central air conditioning is composed of one or more cold and heat source systems and multiple air conditioning systems. It uses the principle of liquid vaporization refrigeration to provide the required cooling capacity for the air conditioning system to offset the heat load of the indoor environment; the heating system provides the required heat for the air conditioning system to offset the cold load of the indoor environment.

[0003] Evaporative heat recovery technology is a widely used energy-saving technology in air conditioning systems. Its basic principle is to discharge indoor heat to the outside through an exhaust fan, and recover the energy in the air during the discharge process. Evaporative heat recovery technology can significantly reduce the energy consumption of buildings, reduce operating costs, and reduce negative impacts on the environment.

[0004] At present, most central air conditioners use primary evaporative heat recovery, and the exhaust temperature is close to the wet bulb temperature before recovery, and only the relative humidity increases. Only the latent heat is recovered, and the sensible heat is not recovered. Therefore, part of the heat is not recovered, which wastes a lot of energy and is not conducive to reducing carbon emissions.

[0005] The condensed water is not fully utilized. The condensed water after energy recovery is directly discharged. The condensed water itself is water without impurities and has a large room for recycling. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a high-efficiency refrigeration system with stepped recovery of condensation heat, which solves the problem that the central air conditioner does not fully recover the evaporation heat and the condensed water is not fully utilized.

[0007] The technical problem to be solved by the present invention is achieved by adopting the following technical scheme: a high-efficiency refrigeration system for stepwise recovery of condensation heat, comprising

[0008] Fresh air unit, exhaust air unit, heat recovery unit, condensing heat recovery mechanism,

[0009] The heat recovery unit is sealed and assembled with the exhaust unit and the fresh air unit in sequence. The exhaust unit is arranged on the side of the heat recovery unit, and the fresh air unit is arranged on the side of the exhaust unit. A part of the condensation heat recovery mechanism is arranged at the bottom of the fresh air unit, and another part is arranged at the top of the heat recovery unit.

[0010] The heat recovery unit can collect exhaust air, the heat recovery unit can perform primary heat exchange on the exhaust air, and the condensing heat recovery mechanism can perform secondary heat exchange on the exhaust air after primary heat exchange; the condensing heat recovery mechanism can absorb the heat after fresh air pre-cooling, and transfer the heat to the exhaust air after primary heat exchange, and a condensing water evaporation device is provided at the bottom of the fresh air unit, and the condensing water evaporation device can evaporate the condensed water collected by the condensing heat recovery mechanism to the fresh air side.

[0011] Preferably, the condensation heat recovery mechanism includes a compressor, a four-way valve, a heat recovery condenser, a fresh air re-cooling evaporator, an air supply section condenser, and a thermal expansion valve.

[0012] Preferably, the exhaust unit comprises an exhaust box, an exhaust valve, and an exhaust mechanism, wherein the exhaust valve is arranged at the bottom of the inner side of the exhaust box close to the heat recovery unit, and the exhaust mechanism is arranged at the top of the exhaust unit; the heat recovery unit comprises a heat recovery box, a spray heat recovery mechanism, a bypass air valve, and an exhaust filter, wherein the spray heat recovery mechanism is arranged in the middle of the heat recovery box, the exhaust filter is arranged at the bottom of the side of the heat recovery box, and the bypass air valve is arranged at the top of the heat recovery box;

[0013] The fresh air unit includes a fresh air box, a fresh air filter, an air supply mechanism, a fresh air pre-cooling coil, the condensed water evaporation device, and the fresh air filter is arranged on the bottom side of the fresh air box. The condensed water evaporation device and the fresh air pre-cooling coil are arranged on the bottom of the fresh air box, and the fresh air pre-cooling coil is arranged on the side of the fresh air filter.

[0014] Preferably, the condensed water evaporation device includes electric heating, electric humidification, a water pump or an ultrasonic humidifier.

[0015] Preferably, the compressor is connected to the four-way valve and is arranged at the bottom of the inner side of the exhaust box; the heat recovery condenser is arranged on the top of the heat recovery unit, one end of the heat recovery condenser is connected to the thermal expansion valve, and the other end is connected to the four-way valve;

[0016] The fresh air re-cooling evaporator and the air supply section condenser are arranged at the bottom of the fresh air unit; one end of the fresh air re-cooling evaporator is connected to the thermal expansion valve, and the other end is connected to the compressor; one end of the air supply section condenser is connected to the thermal expansion valve, and the other end is connected to the four-way valve.

[0017] Preferably, the exhaust fan unit, the heat recovery unit, the fresh air unit and the condensing heat recovery device are provided with three operation modes, namely, a constant temperature and humidity operation mode, a heat recovery operation mode and a dehumidification operation mode.

[0018] Preferably, in the constant temperature and humidity operation mode, the working mode of the condensation heat step recovery high-efficiency refrigeration system is:

[0019] Ventilation steps:

[0020] Step 1: Exhaust air enters the heat recovery box from the exhaust filter;

[0021] Step 2: The exhaust air then enters the spray heat recovery mechanism and exchanges heat with the spray heat recovery mechanism to achieve one-time heat exchange;

[0022] Step 3: The outdoor fresh air enters the heat recovery unit from the bypass air valve and mixes with the exhaust air after the primary heat exchange to form mixed air, and then passes through the heat recovery condenser for secondary heat exchange. The mixed air after the secondary heat exchange is discharged through the exhaust mechanism;

[0023] Fresh air steps:

[0024] Step 4: Fresh air enters the fresh air box from the fresh air filter, first enters the fresh air precooling coil for precooling, and then enters the fresh air recooling evaporator for further cooling;

[0025] Step 5: The unit turns on the condensed water evaporation device according to demand, and processes the temperature and humidity of the fresh air cooled by the fresh air re-cooling evaporator to the required supply air temperature and humidity;

[0026] Step 6: The fresh air treated by the condensed water evaporation device enters the user side through the air supply mechanism;

[0027] The working steps of the condensation heat recovery mechanism are as follows:

[0028] Step a: The fresh air recooling evaporator absorbs heat from the fresh air precooled by the fresh air precooling coil, and transfers the heat to the heat recovery condenser, and the heat recovery condenser can transfer the heat to the mixed air.

[0029] Preferably, in the heat recovery operation mode, the working mode of the condensation heat step recovery high-efficiency refrigeration system is:

[0030] Ventilation steps:

[0031] Step 1: Exhaust air enters the heat recovery box from the exhaust filter;

[0032] Step 2: The exhaust air then enters the spray heat recovery mechanism and exchanges heat with the spray heat recovery mechanism to achieve one-time heat exchange;

[0033] Step 3: The exhaust air after the primary heat exchange is subjected to secondary heat exchange through the heat recovery condenser, and the exhaust air after the secondary heat exchange is discharged through the exhaust mechanism;

[0034] Fresh air steps:

[0035] Step 4: Fresh air enters the fresh air box from the fresh air filter, first enters the fresh air precooling coil for precooling, and then enters the fresh air recooling evaporator for further cooling;

[0036] Step 5: The cooled fresh air enters the user side through the air supply mechanism;

[0037] The working steps of the condensation heat recovery mechanism are as follows:

[0038] Step a: The fresh air re-cooling evaporator absorbs heat from the fresh air pre-cooled by the fresh air pre-cooling coil, and transfers the heat to the heat recovery condenser, and the heat recovery condenser can transfer the heat to the exhaust air after the first heat exchange.

[0039] Preferably, a refrigerant is provided in the condensation heat recovery mechanism, and the refrigerant is capable of transferring heat.

[0040] Preferably, in the dehumidification operation mode, the working mode of the condensation heat step recovery high-efficiency refrigeration system is:

[0041] Ventilation steps:

[0042] Step 1: Exhaust air enters the heat recovery unit from the exhaust filter and enters the exhaust box through the exhaust valve;

[0043] Step 2: exhaust air is discharged through the exhaust mechanism;

[0044] Fresh air steps:

[0045] Step 3: Fresh air enters the fresh air box from the fresh air filter, passes through the fresh air pre-cooling coil and enters the fresh air re-cooling evaporator, is cooled and dehumidified at the fresh air re-cooling evaporator, and then moves to the air supply section condenser for heating, and is finally discharged through the air supply mechanism;

[0046] The working steps of the condensation heat recovery mechanism are as follows:

[0047] The fresh air recooling evaporator cools and dehumidifies the fresh air, and then the fresh air is heated by passing through the air supply section condenser.

[0048] The beneficial effects of the present invention are:

[0049] (1) Through the present invention, the exhaust air is subjected to a heat exchange once through the spray heat recovery mechanism, and the exhaust air after the heat exchange has the characteristics of low temperature and high humidity; by arranging a heat recovery condenser on the top of the spray heat recovery mechanism, the exhaust air after the heat exchange once enters the heat recovery condenser for a secondary heat exchange, which can reduce the condensation temperature of the heat recovery condenser and increase the heat transfer temperature difference, thereby improving the efficiency of the entire condensation heat recovery mechanism.

[0050] (2) Through the present invention, the exhaust air will bring out some water droplets in the spray heat recovery mechanism, and the water droplets evaporate and absorb heat on the surface of the heat recovery condenser, thereby increasing the heat exchange coefficient of the heat recovery condenser and increasing the efficiency of the entire condensation heat recovery mechanism.

[0051] (3) Through the present invention, the recovery condenser can block the water droplets brought out by the exhaust air from the spray heat recovery mechanism, so that the brought out water droplets flow back into the spray heat recovery mechanism, which can effectively reduce the loss of the spray water heat recovery mechanism.

[0052] (4) Through the present invention, the existing condensation heat recovery mechanism is utilized, and a heat recovery condenser is set on the top of the condenser, which reduces the need to install other boxes on the equipment. It is only necessary to install a condensation heat recovery mechanism inside the original box to achieve secondary heat exchange of the exhaust air.

[0053] (5) Through the present invention, a device for treating condensed water is added to the fresh air unit: electric heating and electric humidification; electric heating and electric humidification can further treat the condensed water and convert the condensed water into atomized water particles, so that the fresh air can adjust the relative humidity of the indoor air; when humans are in an environment with a temperature of 22-26°C and a relative humidity of 40%-60%, life and work feel most suitable and work efficiency is the highest. The atomized water can absorb heat and vaporize in the air, thereby humidifying the air. This method is also a humidification process close to isenthalpy.

[0054] (6) Through the present invention, a bypass air valve is arranged on the top side of the heat recovery box body, and fresh air is introduced from the outside through the bypass air valve to mix with the exhaust air after the first heat exchange, ensuring sufficient air volume for heat exchange with the heat recovery condenser, which not only ensures the safe and efficient operation of the condensation heat recovery mechanism, but also improves the energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic diagram of the internal structure of the present invention.

[0056] Figure 2 This is the working process of the constant temperature and humidity operation mode of the present invention.

[0057] Figure 3 This is the heat recovery operation mode workflow of the present invention.

[0058] Figure 4This is the workflow of the dehumidification operation mode of the present invention.

[0059] In the figure: fresh air unit -1, fresh air box -11, fresh air filter -12, air supply mechanism -13, fresh air pre-cooling coil -14, electric heating -15, electric humidification -16, water pump -17, exhaust fan unit -2, exhaust box -21, exhaust mechanism -22, exhaust valve -23, heat recovery unit -3, heat recovery box -31, exhaust filter -32, spray heat recovery mechanism -33, bypass air valve -34, condensation heat recovery mechanism -4, compressor -41, four-way valve -42, heat recovery condenser -43, fresh air re-cooling evaporator -44, air supply section condenser -45, thermal expansion valve -46. DETAILED DESCRIPTION

[0060] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0061] Example 1

[0062] like Figure 1-Figure 4 As shown, a high-efficiency refrigeration system with stepped condensation heat recovery includes a fresh air unit 1, an exhaust air unit 2, a heat recovery unit 3, and a condensation heat recovery mechanism 4.

[0063] Reference Figure 1 The heat recovery unit 3 is sealed and assembled with the exhaust fan unit 2 and the fresh air unit 1 in sequence. The exhaust fan unit 2 is arranged on the side of the heat recovery unit 3, and the fresh air unit 1 is arranged on the side of the exhaust fan unit 2. A part of the condensation heat recovery mechanism 4 is arranged at the bottom of the fresh air unit 1, and the other part is arranged at the top of the heat recovery unit 3.

[0064] In this embodiment, exhaust air enters from the heat recovery unit 3, and the heat recovery unit 3 performs a primary heat exchange on the exhaust air. The exhaust air after the primary heat exchange by the heat recovery unit 3 undergoes a secondary heat exchange through a condensation heat recovery mechanism 4 arranged on the top of the heat recovery unit 3. The condensation heat recovery mechanism 4 can absorb the heat after the fresh air is pre-cooled, and transfer the heat to the exhaust air after the primary heat exchange. A condensation water evaporation device is provided at the bottom of the fresh air unit 1, and the evaporation device can evaporate the condensation water collected by the condensation heat recovery mechanism to the fresh air side.

[0065] In this embodiment, the exhaust unit 2 includes an exhaust box 21, an exhaust structure 22, and an exhaust valve 23; the heat recovery unit 3 includes a heat recovery box 31, an exhaust filter 32, a spray heat recovery mechanism 33, and a bypass air valve 34; the fresh air unit 1 includes a fresh air box 11, a fresh air filter 12, an air supply mechanism 13, a fresh air pre-cooling coil 14, an electric heater 15, an electric humidifier 16, and a water pump 17; the condensation heat recovery mechanism 4 includes a compressor 41, a four-way valve 42, a heat recovery condenser 43, a fresh air re-cooling evaporator 44, an air supply section condenser 45, and a thermal expansion valve 46.

[0066] Reference Figure 1 A heat recovery box 31 is arranged on the side of the exhaust box 21, an exhaust valve 23 is arranged at the bottom of the exhaust box 21 and connected to the heat recovery box 31, the top of the exhaust box 21 is connected to the top of the heat recovery box 31, and an exhaust mechanism 22 is arranged at the top of the exhaust box 21.

[0067] A bypass air valve 34 is provided at the top of the opposite side of the heat recovery box 31 and the exhaust box 21, and an exhaust filter 32 is provided at the bottom of the opposite side; a spray heat recovery mechanism 33 is provided at the inner middle of the heat recovery box 31. Exhaust air can enter the heat recovery box from the exhaust filter 32, and fresh air can enter the heat recovery box from the bypass air valve 34.

[0068] The exhaust air entering the heat recovery box 31 from the exhaust filter 32 can undergo a primary heat exchange through the spray heat recovery mechanism 33, and the fresh air entering the heat recovery box 31 from the bypass air valve 34 is mixed with the exhaust air after the primary heat exchange, and undergoes a secondary heat exchange through the heat recovery condenser 43. The fresh air entering the heat recovery box 31 from the bypass air valve 34 does not undergo heat exchange through the spray heat recovery mechanism 33, and is then discharged from the exhaust box 21 through the exhaust mechanism 22.

[0069] As another embodiment, the bypass air valve 34 can be closed, and the fresh air cannot enter the heat recovery unit 3 from the bypass air valve 34. The exhaust filter 32 can guide the exhaust air, and the exhaust air enters the heat recovery unit 3 from the exhaust filter 32, and enters the exhaust box 21 from the exhaust valve 23 set at the bottom of the exhaust box 21. After entering the exhaust box 21, the exhaust air moves upward to the exhaust structure 22, and is discharged from the exhaust box 21 through the exhaust structure 22.

[0070] A spray heat recovery mechanism 33 is provided in the middle of the inner side of the heat recovery box 31, a condensation heat recovery mechanism 4 is provided on the top of the heat recovery box 31, the bottom of the heat recovery box 31 is connected to the exhaust box 21, and the top of the heat recovery box 31 is connected to the exhaust box 21.

[0071] The condensation heat recovery mechanism 4 disposed on the top of the heat recovery box 31 includes a heat recovery condenser 43.

[0072] The flow direction of exhaust air is:

[0073] When the exhaust valve 23 is closed and the bypass valve 34 is open,

[0074] 1. Exhaust air enters the heat recovery box 31 from the exhaust filter 32, is blocked by the exhaust valve 23, flows upward through the spray heat recovery mechanism 33, passes through the heat recovery condenser 43, and then flows into the exhaust box 21.

[0075] , and then discharged from the exhaust box 21 by the exhaust mechanism 22.

[0076] 2. When the bypass air valve 34 is in an open state, fresh air can enter the heat recovery box through the bypass air valve 34 and then enter the exhaust box 21 after passing through the heat recovery condenser 43 , and then be discharged from the exhaust box 21 by the exhaust mechanism 22 .

[0077] The exhaust filter 32 is always kept in an open state, and when the bypass air valve 34 is in a closed state, the exhaust valve 23 is opened. At this time, the flow of exhaust air is:

[0078] 3. The bypass air valve 34 is closed, the exhaust valve 23 is opened, and the exhaust air enters the heat recovery box 31 from the exhaust filter 32, then enters the exhaust box 21 through the exhaust valve 23, and then flows upward to the exhaust mechanism 22.

[0079] The exhaust box 21 is exhausted by the exhaust mechanism 22 .

[0080] When the exhaust air has a flow direction of 3, the exhaust air does not pass through the spray heat recovery mechanism 33, and the exhaust air has a flow direction of 1, 2 or 3.

[0081] When the exhaust valve 23 and the bypass air valve 34 are both in the closed state,

[0082] 4. The exhaust air enters the heat recovery box 31 from the exhaust filter 32, is blocked by the exhaust valve 23, flows upward through the spray heat recovery mechanism 33, passes through the heat recovery condenser 43, and then flows into the exhaust box 21, and is then discharged from the exhaust box 21 by the exhaust mechanism 22.

[0083] Reference Figure 1 The fresh air unit 1 is arranged on the side of the exhaust fan unit 2 and on the opposite side of the heat recovery unit 3. The fresh air unit 1 includes a fresh air box 11, a fresh air filter 12, an air supply mechanism 13, a fresh air pre-cooling coil 14, an electric heater 15, an electric humidifier 16, and a water pump 17.

[0084] In this embodiment, the fresh air filter 12 is arranged at the side bottom of the fresh air box 11; the fresh air precooling coil 14 is arranged at the inner bottom of the fresh air box 11, near the fresh air filter 12; a condensation heat recovery mechanism 4 is arranged on the other side of the fresh air filter 12; an electric heater 15 is arranged on the other side of the condensation heat recovery mechanism 4; an electric humidifier 16 is arranged on the other side of the electric heater 15; a water pump 17 is arranged on the other side of the electric humidifier 16; and the air supply mechanism 13 is arranged on the top of the fresh air box 11;

[0085] A partial condensation heat recovery mechanism 4 is arranged at the bottom of the exhaust fan unit 2 and is connected to the condensation heat recovery mechanism 4 arranged at the bottom of the fresh air unit 1 through a pipeline.

[0086] The flow direction of the fresh air is: the fresh air only flows in the fresh air box 11, enters the fresh air box 11 from the fresh air filter 12, flows through the fresh air pre-cooling coil 14, passes through the condensation heat recovery mechanism 4 set in the fresh air box 11, and then flows upward to the air supply mechanism 13 and is discharged from the fresh air unit 1.

[0087] The condensation heat recovery mechanism 4 includes a compressor 41 , a four-way valve 42 , a heat recovery condenser 43 , a fresh air re-cooling evaporator 44 , an air supply section condenser 45 , and a thermal expansion valve 46 .

[0088] In this embodiment, the condensation heat recovery mechanism 4 is arranged at the bottom of the fresh air unit 1: the fresh air re-cooling evaporator 44 is arranged on one side of the fresh air pre-cooling coil 14; the other side of the fresh air re-cooling evaporator 44 is provided with an air supply section condenser 45; the other side of the air supply section condenser 45 is provided with a thermal expansion valve 46;

[0089] The condensation heat recovery mechanism 4 is arranged in the exhaust unit 2: the four-way valve 42 is arranged on the side close to the fresh air box 11; the compressor 41 is arranged on the other side of the four-way valve 42 and connected to the four-way valve 42;

[0090] The condensation heat recovery mechanism 4 is arranged on the top of the heat recovery unit 3: the heat recovery condenser 43 is arranged on the top of the heat recovery unit 3; the heat recovery condenser 43 is connected to the thermal expansion valve 46 through a pipeline.

[0091] In this embodiment, the heat recovery condenser 43 is placed obliquely on the top of the heat recovery unit 3, so as to expand the contact area between the exhaust air and the heat recovery condenser 43.

[0092] In this embodiment, one end of the heat recovery condenser 43 is connected to the thermal expansion valve 46, and the other end is connected to the four-way valve 42; the compressor 41 is connected to the four-way valve 42; one end of the fresh air re-cooling evaporator 44 is connected to the thermal expansion valve 46, and the other end is connected to the compressor 41; one end of the air supply section condenser 45 is connected to the four-way valve 42, and the other end is connected to the thermal expansion valve 46.

[0093] In this embodiment, the condensation heat step recovery high-efficiency refrigeration system is provided with three operation modes, namely: constant temperature and humidity operation mode, heat recovery operation mode and dehumidification operation mode.

[0094] Reference Figure 2-4 ,in Figure 2 The constant temperature and humidity operation mode workflow of the efficient refrigeration system for condensation heat cascade recovery, Figure 3 The workflow for heat recovery operation mode, Figure 4 This is the working process of dehumidification operation mode.

[0095] Figure 2-Figure 4 The direction of the middle arrow indicates the flow direction of exhaust and fresh air.

[0096] Reference Figure 2 When the condensation heat step recovery high-efficiency refrigeration system is in a constant temperature and humidity operation mode, the exhaust valve 23 is in a closed state and the bypass air valve 34 is in an open state.

[0097] The flow of exhaust air is as follows: the exhaust air enters the interior of the heat recovery box 31 from the exhaust air filter 32, is blocked by the exhaust air valve 23, flows upward through the spray heat recovery mechanism 33, and enters the top of the heat recovery box 31;

[0098] Fresh air enters the top of the heat recovery box 31 through the bypass air valve 34, mixes with the exhaust air entering the heat recovery box 31 from the exhaust filter 32, enters the exhaust box 21 after the heat recovery condenser 43, and is then discharged from the exhaust box 21 by the exhaust mechanism 22.

[0099] When the exhaust air passes through the spray heat recovery mechanism 33, heat exchange is performed once. At this time, the temperature of the exhaust air is close to the wet bulb temperature before recovery, and only the relative humidity increases. The latent heat of the exhaust air is recovered, but the sensible heat is not fully recovered;

[0100] The exhaust air after the primary heat exchange is mixed with the fresh air entering the top of the heat recovery box 31 from the bypass air valve 34, and the mixed air undergoes secondary heat exchange in the heat recovery condenser 43. The mixed air after the secondary heat exchange is discharged outdoors through the exhaust mechanism 22.

[0101] During the secondary heat exchange process, the exhaust air changes as follows: the exhaust air temperature after the secondary heat exchange increases, and part of the moisture inside the spray heat recovery mechanism 33 is brought out during the heat exchange process, and part of the moisture brought out is blocked by the heat recovery condenser 43 and drips back to the spray heat recovery mechanism 22, and the other part of the moisture is vaporized and converted into water vapor and discharged with the exhaust air.

[0102] The flow of fresh air is as follows: the fresh air enters the fresh air box from the fresh air filter 12, is pre-cooled by the fresh air pre-cooling coil 14, flows into the fresh air re-cooling evaporator 44 for further cooling, and then is adjusted in temperature and humidity by the electric heater 15 and the electric humidifier 16, and then enters the air supply mechanism 13 to deliver the fresh air to the use side.

[0103] Reference Figure 3 When the condensing heat step recovery high-efficiency refrigeration system is in the heat recovery operation mode, the exhaust valve 23 and the bypass air valve 34 are in the closed state.

[0104] The flow of exhaust air is as follows: the exhaust air enters the heat recovery box 31 from the exhaust filter 32, is blocked by the exhaust valve 23, flows upward through the spray heat recovery mechanism 33, then enters the exhaust box 21 from the heat recovery condenser 43, and is subsequently discharged from the exhaust box 21 by the exhaust mechanism 22.

[0105] When the exhaust air passes through the spray heat recovery mechanism 33, a heat exchange is performed. At this time, the temperature of the exhaust air is close to the wet bulb temperature before recovery, and only the relative humidity increases. The latent heat of the exhaust air is recovered, but the sensible heat is not fully recovered; the exhaust air after the primary heat exchange is subjected to a secondary heat exchange with the heat recovery condenser 43, and the exhaust air after the secondary heat exchange is discharged outdoors through the exhaust mechanism 22.

[0106] During the secondary heat exchange process, the exhaust air changes as follows: the exhaust air temperature after the secondary heat exchange increases, and part of the moisture inside the spray heat recovery mechanism 33 is taken out during the heat exchange process. Part of the moisture taken out is blocked by the heat recovery condenser 43 and drips back to the spray heat recovery mechanism 22, and the other part of the moisture is vaporized and converted into water vapor and discharged with the exhaust air.

[0107] The flow of fresh air is as follows: the fresh air enters the fresh air box from the fresh air filter 12, is pre-cooled by the fresh air pre-cooling coil 14, flows into the fresh air re-cooling evaporator 44 for further cooling, and then enters the air supply mechanism 13 to deliver the fresh air to the use side.

[0108] When the refrigeration system is in the constant temperature and humidity operation mode and the heat recovery operation mode, the condensation heat recovery mechanism 4 absorbs the heat of the fresh air through the fresh air re-cooling evaporator 44, and the heat is transferred to the heat recovery condenser 43 through the thermal expansion valve 43. The heat recovery condenser 43 can transfer the heat to the exhaust air after the first heat exchange, thereby realizing the secondary recovery of the exhaust air energy.

[0109] In this embodiment, the medium for heat transfer is a refrigerant, which can absorb or release heat through phase change. The compressor 41 can compress the refrigerant into a high-temperature and high-pressure gas state, and drive the refrigerant to run in the condensation heat recovery mechanism 4. The heat recovery condenser 43 can transfer the heat of the refrigerant to the exhaust air; the fresh air re-cooling evaporator 44 can absorb the heat of the pre-cooled fresh air, so that the pre-cooled fresh air is further cooled.

[0110] After the refrigerant absorbs heat in the fresh air re-cooling evaporator 44, it is converted into a low-temperature and low-pressure gaseous refrigerant to achieve a refrigeration effect. The low-temperature and low-pressure gaseous refrigerant enters the compressor 41 for compression to become a high-temperature and high-pressure gaseous refrigerant. The high-temperature and high-pressure gaseous refrigerant passes through the four-way valve 42 and enters the heat recovery condenser 43 for heat dissipation. The refrigerant after heat dissipation is converted into a medium-temperature and high-pressure liquid refrigerant. The medium-temperature and high-pressure liquid refrigerant enters the thermal expansion valve 43 for throttling to become a low-temperature and low-pressure liquid refrigerant. The low-temperature and low-pressure liquid refrigerant then enters the fresh air re-cooling evaporator 44 for heat absorption to achieve a refrigeration cycle.

[0111] When the refrigeration system is in dehumidification mode, refer to Figure 4 At this time, the bypass air valve 34 is in a closed state and the exhaust valve 23 is in an open state.

[0112] The flow of exhaust air is as follows: the exhaust air enters the heat recovery box 31 from the exhaust filter 32 , then enters the exhaust box 21 through the exhaust valve 23 , then flows upward to the exhaust mechanism 22 , and is discharged from the exhaust box 21 by the exhaust mechanism 22 .

[0113] The flow of fresh air is as follows: the fresh air enters the fresh air box 11 from the fresh air filter 12, passes through the fresh air pre-cooling coil 14, flows into the fresh air re-cooling evaporator 44 for cooling and dehumidification, then passes through the air supply section condenser 45 for heating, and finally enters the air supply mechanism 13 to deliver the fresh air to the use side.

[0114] When the refrigeration system is in the dehumidification operation mode, the condensation heat recovery mechanism 4 does not cooperate with the heat recovery unit 3 and the exhaust unit 2, and the fresh air pre-cooling coil 14 does not work. The fresh air is cooled and dehumidified in the fresh air re-cooling evaporator 44, and then heated in the air supply section condenser 45 and enters the use side through the air supply mechanism 36. The state of the refrigerant is: the low-temperature and low-pressure liquid refrigerant is converted into a low-temperature and low-pressure gaseous refrigerant after absorbing heat in the fresh air re-cooling evaporator 44, and the low-temperature and low-pressure gaseous refrigerant enters the compressor 41 for compression and becomes a high-temperature and high-pressure gaseous refrigerant. The high-temperature and high-pressure gaseous refrigerant passes through the four-way valve 42 and enters the air supply section condenser 45 to dissipate heat and become a medium-temperature and high-pressure liquid refrigerant. The medium-temperature and high-pressure liquid refrigerant enters the thermal expansion valve 43 for throttling and becomes a low-temperature and low-pressure liquid refrigerant. The low-temperature and low-pressure liquid refrigerant enters the fresh air re-cooling evaporator 44 to absorb heat to realize the refrigeration cycle.

[0115] In the present embodiment, an exhaust fan is arranged inside the exhaust mechanism 22, and the exhaust fan can guide the exhaust air from the exhaust filter 32 into the heat recovery box 31, and then enter the exhaust box through the spray heat recovery mechanism 33, the heat recovery condenser 43 or the exhaust valve 23, and be discharged from the exhaust mechanism 22 to the exhaust box 21 along the air duct; an exhaust fan is also arranged inside the air supply mechanism 13, and the exhaust fan arranged inside the air supply mechanism 13 can guide the fresh air from the fresh air filter 12 into the fresh air box 11, and be discharged from the fresh air box 11 from the air supply mechanism 13 along the air duct.

[0116] In this embodiment, by installing the compressor 41 of the condensation heat recovery mechanism 4 at the bottom of the exhaust fan unit 2, the heat generated by the compressor 41 during operation is prevented from diffusing into the fresh air duct, thereby avoiding increasing the workload of the fresh air unit 1. In addition, there is no need to set up an additional box of the condensation heat recovery mechanism 4, and the condensation heat recovery mechanism 4 is integrated into the exhaust fan unit 2, the heat recovery unit 3, and the fresh air unit 1 to reduce the installation cost.

[0117] The heat recovery condenser 43 of the condensing heat recovery mechanism 4 is arranged on the top of the heat recovery box 31 and the top of the spray heat recovery mechanism 33. The exhaust air can pass through the heat recovery condenser 43 after a heat exchange at the spray heat recovery mechanism 22. The heat recovery condenser 43 transfers the heat of the refrigerant to the exhaust air, thereby realizing secondary heat exchange of the exhaust air. Since the exhaust air temperature after the first heat exchange is still relatively low, when the exhaust air after the first heat exchange exchanges heat with the heat recovery condenser 43, the temperature difference between the exhaust air and the refrigerant increases, thereby improving the efficiency of the condensing heat recovery mechanism 4.

[0118] In this embodiment, the fresh air re-cooling evaporator 44 of the condensing heat recovery mechanism 4 is arranged on one side of the fresh air pre-cooling coil 14. The fresh air is pre-cooled by the fresh air pre-cooling coil 14 and then cooled by the fresh air re-cooling evaporator 44, thereby re-cooling the pre-cooled fresh air.

[0119] In this embodiment, the air supply section condenser 45 of the condensation heat recovery mechanism 4 is placed behind the fresh air re-cooling evaporator 44. After the fresh air is cooled and dehumidified in the fresh air re-cooling evaporator 44, it is heated by the air supply section condenser 45 to realize the dehumidification and reheating function of the fresh air.

[0120] In this embodiment, the temperature of the exhaust air after the primary heat exchange is close to the wet-bulb temperature of the exhaust air before recovery, and the relative humidity is increased; when the exhaust air after the primary heat exchange undergoes secondary heat exchange in the heat recovery condenser 43, part of the water droplets brought out of the spray heat recovery mechanism 22 by the exhaust air will evaporate and absorb heat on the surface of the heat recovery condenser 43, which can effectively increase the heat exchange coefficient of the heat recovery condenser 43, thereby increasing the efficiency of the entire condensation heat recovery mechanism 4. The heat recovery condenser 43 has the function of a water baffle, and part of the water is blocked by the heat recovery condenser 43 and drips back to the spray heat recovery mechanism 22, and the other part of the water is converted into water vapor after vaporization and discharged with the exhaust air, which can effectively reduce the loss of the unit spray water.

[0121] In this embodiment, an electric heater 15, an electric humidifier 16 and a water pump 17 are provided in the fresh air unit 1. When the air humidity on the fresh air side needs to be adjusted, the electric heater 15, the electric humidifier 16 and the water pump 17 in the fresh air unit 1 can adjust the air humidity on the fresh air side by using the condensed water generated when the condensation heat recovery mechanism 4 is working. The water pump 17 pumps the condensed water into the electric heater 15 and the electric humidifier 16. The electric humidifier 16 can convert the condensed water into water mist, mix it with the fresh air side, and discharge it into the fresh air side through the air supply mechanism 13, thereby increasing the air humidity on the fresh air side.

[0122] The atomized water in the fresh air side can absorb heat and vaporize in the air, thereby humidifying the air. This method is also a humidification process close to isenthalpy. At the same time, the atomized water can absorb heat and vaporize in the air, which helps to reduce the temperature on the fresh air side and improve energy utilization efficiency.

[0123] In this embodiment, the electric heater 15, the electric humidifier 16, and the water pump 17 provided in the fresh air unit 1 can be started manually; or started by automatic control, specifically:

[0124] In the environment where the refrigeration system is used, an air detection device is provided, which can detect the temperature and humidity of the air. When the humidity is lower than a specified value, the electric heating 15, the electric humidification 16 and the water pump 17 are started until the humidity on the fresh air side reaches a specified value.

[0125] In this embodiment, when the user side has relatively high requirements for air quality, the unit enters a constant temperature and humidity operation mode. At this time, the output capacity of the condensing heat recovery mechanism 4 increases to ensure sufficient cooling capacity. The fresh air is processed to the set temperature and humidity values ​​through the adjustment of the electric heating 15 and the electric humidification 16. At the same time, the heat of the heat recovery condenser 43 increases. When the exhaust air volume is not enough to completely take away the heat of the heat recovery condenser 43, it is necessary to open the bypass air valve 34 to introduce outdoor fresh air to ensure that there is enough air volume for heat exchange with the heat recovery condenser 43, which not only realizes the safe and efficient operation of the condensing heat recovery mechanism 4, but also enables the temperature and humidity of the air on the user side to be accurately controlled.

[0126] When the user side has relatively low requirements for air quality, the unit enters the heat recovery operation mode. In this mode, only the heat of the exhaust air is recovered and utilized, and the temperature and humidity of the air on the user side are not controlled. At this time, the output capacity of the condensation heat recovery mechanism 4 is controlled within the range where the exhaust air can just take away the heat in the heat recovery condenser 43, thereby realizing efficient recovery of exhaust air energy.

[0127] As another embodiment, the condensate evaporation device adopts an ultrasonic humidifier. At this time, the electric heating 15, the electric humidifier 16, and the water pump 17 are replaced by an ultrasonic generator, a vibrating plate, and a water tank. At this time, the condensate flows into the water tank, and the ultrasonic generator drives the vibrating plate to vibrate, so that the condensate is atomized, mixed with the fresh air, and discharged into the fresh air side.

[0128] By using an ultrasonic generator, the humidification intensity on the fresh air side can be guaranteed to be high, the humidification is uniform, and the humidification efficiency is high. Compared with the electric heating and electric humidification methods, the use of ultrasonic humidifiers can reduce energy loss. In addition, the condensed water does not contain other impurities, which meets the conditions for long-term use of ultrasonic humidifiers.

[0129] The basic principles, main features and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A high-efficiency refrigeration system with step-by-step recovery of condensation heat, comprising: Fresh air unit, exhaust air unit, heat recovery unit, condensing heat recovery mechanism, The heat recovery unit is sealed and assembled with the exhaust unit and the fresh air unit in sequence. The exhaust unit is arranged on the side of the heat recovery unit, and the fresh air unit is arranged on the side of the exhaust unit. A part of the condensation heat recovery mechanism is arranged at the bottom of the fresh air unit, and another part is arranged at the top of the heat recovery unit. Features: The heat recovery unit can collect exhaust air, the heat recovery unit can perform primary heat exchange on the exhaust air, and the condensing heat recovery mechanism can perform secondary heat exchange on the exhaust air after primary heat exchange; the condensing heat recovery mechanism can absorb the heat after fresh air pre-cooling, and transfer the heat to the exhaust air after primary heat exchange, and a condensing water evaporation device is provided at the bottom of the fresh air unit, and the condensing water evaporation device can evaporate the condensed water collected by the condensing heat recovery mechanism to the fresh air side.

2. The high-efficiency refrigeration system with stepwise recovery of condensation heat according to claim 1, characterized in that: The condensation heat recovery mechanism includes a compressor, a four-way valve, a heat recovery condenser, a fresh air re-cooling evaporator, an air supply section condenser, and a thermal expansion valve.

3. The high-efficiency refrigeration system with stepwise recovery of condensation heat according to claim 1, characterized in that: The exhaust unit includes an exhaust box, an exhaust valve, and an exhaust mechanism. The exhaust valve is arranged at the bottom of the inner side of the exhaust box near the heat recovery unit, and the exhaust mechanism is arranged at the top of the exhaust unit; the heat recovery unit includes a heat recovery box, a spray heat recovery mechanism, a bypass air valve, and an exhaust filter. The spray heat recovery mechanism is arranged in the middle of the heat recovery box, the exhaust filter is arranged at the bottom of the side of the heat recovery box, and the bypass air valve is arranged at the top of the heat recovery box; The fresh air unit includes a fresh air box, a fresh air filter, an air supply mechanism, a fresh air pre-cooling coil, the condensed water evaporation device, and the fresh air filter is arranged on the bottom side of the fresh air box. The condensed water evaporation device and the fresh air pre-cooling coil are arranged on the bottom of the fresh air box, and the fresh air pre-cooling coil is arranged on the side of the fresh air filter.

4. The high-efficiency refrigeration system with stepwise recovery of condensation heat according to claim 3, characterized in that: The condensed water evaporation device includes electric heating, electric humidification, a water pump or an ultrasonic humidifier.

5. A high-efficiency refrigeration system for stepwise recovery of condensation heat according to any one of claims 1 to 4, characterized in that: The compressor is connected to the four-way valve and is arranged at the inner bottom of the exhaust box; the heat recovery condenser is arranged on the top of the heat recovery unit, one end of the heat recovery condenser is connected to the thermal expansion valve, and the other end is connected to the four-way valve; The fresh air re-cooling evaporator and the air supply section condenser are arranged at the bottom of the fresh air unit; one end of the fresh air re-cooling evaporator is connected to the thermal expansion valve, and the other end is connected to the compressor; one end of the air supply section condenser is connected to the thermal expansion valve, and the other end is connected to the four-way valve.

6. The high-efficiency refrigeration system with stepwise recovery of condensation heat according to claim 5, characterized in that: The exhaust fan unit, the heat recovery unit, the fresh air unit, and the condensing heat recovery device are provided with three operation modes, namely, a constant temperature and humidity operation mode, a heat recovery operation mode, and a dehumidification operation mode.

7. The high-efficiency refrigeration system with stepwise recovery of condensation heat according to claim 6, characterized in that: In the constant temperature and humidity operation mode, the working mode of the condensation heat step recovery high-efficiency refrigeration system is as follows: Ventilation steps: Step 1: Exhaust air enters the heat recovery box from the exhaust filter; Step 2: The exhaust air then enters the spray heat recovery mechanism and exchanges heat with the spray heat recovery mechanism to achieve one-time heat exchange; Step 3: The outdoor fresh air enters the heat recovery unit from the bypass air valve and mixes with the exhaust air after the primary heat exchange to form mixed air, and then passes through the heat recovery condenser for secondary heat exchange. The mixed air after the secondary heat exchange is discharged through the exhaust mechanism; Fresh air steps: Step 4: Fresh air enters the fresh air box from the fresh air filter, first enters the fresh air precooling coil for precooling, and then enters the fresh air recooling evaporator for further cooling; Step 5: The unit turns on the condensed water evaporation device according to demand, and processes the temperature and humidity of the fresh air cooled by the fresh air re-cooling evaporator to the required supply air temperature and humidity; Step 6: The fresh air treated by the condensed water evaporation device enters the user side through the air supply mechanism; The working steps of the condensation heat recovery mechanism are as follows: Step a: The fresh air recooling evaporator absorbs heat from the fresh air precooled by the fresh air precooling coil, and transfers the heat to the heat recovery condenser, and the heat recovery condenser can transfer the heat to the mixed air.

8. The high-efficiency refrigeration system with stepwise recovery of condensation heat according to claim 6, characterized in that: In the heat recovery operation mode, the working mode of the condensation heat step recovery high-efficiency refrigeration system is as follows: Ventilation steps: Step 1: Exhaust air enters the heat recovery box from the exhaust filter; Step 2: The exhaust air then enters the spray heat recovery mechanism and exchanges heat with the spray heat recovery mechanism to achieve one-time heat exchange; Step 3: The exhaust air after the primary heat exchange is subjected to secondary heat exchange through the heat recovery condenser, and the exhaust air after the secondary heat exchange is discharged through the exhaust mechanism; Fresh air steps: Step 4: Fresh air enters the fresh air box from the fresh air filter, first enters the fresh air precooling coil for precooling, and then enters the fresh air recooling evaporator for further cooling; Step 5: The cooled fresh air enters the user side through the air supply mechanism; The working steps of the condensation heat recovery mechanism are as follows: Step a: The fresh air re-cooling evaporator absorbs heat from the fresh air pre-cooled by the fresh air pre-cooling coil, and transfers the heat to the heat recovery condenser, and the heat recovery condenser can transfer the heat to the exhaust air after the first heat exchange.

9. A high-efficiency refrigeration system for stepwise recovery of condensation heat according to any one of claims 7-8, characterized in that: The condensation heat recovery mechanism is provided with a refrigerant, and the refrigerant is capable of transferring heat.

10. The high-efficiency refrigeration system with stepwise recovery of condensation heat according to claim 6, characterized in that: In the dehumidification operation mode, the working mode of the condensation heat step recovery high-efficiency refrigeration system is as follows: Ventilation steps: Step 1: Exhaust air enters the heat recovery unit from the exhaust filter and enters the exhaust box through the exhaust valve; Step 2: exhaust air is discharged through the exhaust mechanism; Fresh air steps: Step 3: Fresh air enters the fresh air box from the fresh air filter, passes through the fresh air pre-cooling coil and enters the fresh air re-cooling evaporator, is cooled and dehumidified at the fresh air re-cooling evaporator, and then moves to the air supply section condenser for heating, and is finally discharged through the air supply mechanism; The working steps of the condensation heat recovery mechanism are as follows: The fresh air recooling evaporator cools and dehumidifies the fresh air, and then the fresh air is heated by passing through the air supply section condenser.

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