Heat recovery type fresh air dehumidifier combining heat pump and rotary wheel and control method thereof

Abstract

This invention relates to a heat recovery type fresh air dehumidifier combining a heat pump and a rotary dehumidifier, and its control method. The heat recovery type high-efficiency fresh air dehumidifier includes an air flow path, a rotary dehumidifier, and a refrigerant loop. The air flow path includes an exhaust duct and an supply duct spaced apart from each other. The exhaust duct has a return air inlet and an exhaust air outlet at each end. The supply air duct has a supply air outlet and a fresh air inlet at each end. The refrigerant loop includes a compressor, a four-way reversing valve, a first shut-off valve, an adjustable three-way valve, an exhaust coil, a fifth shut-off valve, a first throttling device, a second one-way valve, a supply coil, and a third shut-off valve connected in sequence. Compared with existing technologies, this invention utilizes a rotary dehumidifier for heat recovery, which can recover indoor energy, regulate the temperature and humidity of fresh air, reduce the dehumidification load of the heat pump circulation cooling dehumidification, lower the dehumidification energy consumption of the heat pump unit, and further improve energy efficiency.

Description

Technical Field

[0001] This invention relates to a fresh air dehumidifier, and more particularly to a heat pump combined with a rotor heat recovery type high-efficiency fresh air dehumidifier and its control method. Background Technology

[0002] There are two types of air dehumidifiers: heat recovery dehumidifiers and dehumidifiers. In a typical heat recovery dehumidifier, one half receives fresh air and the other half receives exhaust air. The two air streams have temperature and humidity differences. Utilizing the moisture adsorption and heat storage capacity of the rotating core material, the rotation of the dehumidifier achieves heat and moisture exchange between the two sides of the air, thus realizing heat recovery. A dehumidifier dehumidifier also consists of two parts: one part adsorbs and dehumidifies the air, and the other part uses high-temperature regeneration air for desorption and regeneration. Compared to dehumidifier dehumidifiers, heat recovery dehumidifiers rotate at a faster speed. Generally, the two types of dehumidifiers are made of different materials.

[0003] Heat pump heat recovery technology utilizes indoor exhaust air to condense or evaporate the refrigerant in the heat exchanger, thereby recovering energy from the exhaust air. This has become a crucial technology for energy conservation in modern buildings. Heat pump heat recovery dehumidifiers employing this technology can reduce the energy consumption of the unit's compressor and avoid cross-infection caused by traditional exhaust heat recovery methods, improving indoor air quality while saving energy.

[0004] With the increasing use of fresh air dehumidifiers, in order to further standardize product energy efficiency and improve user comfort, the new national standard has put forward higher requirements for the filtration, cooling (heating) and dehumidification of residential fresh air dehumidifiers, which undoubtedly brings more challenges to the design of fresh air dehumidifiers.

[0005] Chinese patent application number 201810585463.7 proposes an integrated heat pump heat recovery type fresh air dehumidifier with internal circulation mode, which realizes three modes: internal circulation, cooling dehumidification, and heating through control design. However, in this patent, the fresh air is directly sent into the room after being cooled and dehumidified by the evaporator, resulting in a low supply air temperature in summer, which is difficult to meet the standard of not less than 22°C in summer as required by the new national standard, resulting in poor user comfort.

[0006] In response, Chinese patent application number 202111233521.8 proposes an integrated heat pump heat recovery type fresh air dehumidifier. In addition to the inlet coil, exhaust coil, and subcooling coil, this patent also includes a supply coil and corresponding bypass piping. By adjusting the damper opening and closing and changing the flow path, it can select either subcooling reheat or condensation reheat for reheating, ensuring that the supply air temperature reaches or exceeds the minimum supply air temperature of 22℃ specified in the new national standard. Due to the bypass piping at the supply coil, the refrigerant flowing out of the inlet coil in heating and internal circulation modes does not flow through the supply coil, effectively avoiding heat loss in the supply air. However, this invention relies on the air to cool down and release moisture at the evaporator under different operating conditions. In high air volume environments, the evaporator cooling and dehumidification load is large, the heat pump unit has high dehumidification energy consumption, and the compressor power consumption is high, resulting in reduced unit energy efficiency. It is not suitable for use under high air volume conditions. In internal circulation mode, the indoor return air has a low humidity content and a large enthalpy difference between the air before and after cooling and dehumidification. Directly using cooling and dehumidification to achieve the target air humidity content will increase the power consumption of the compressor. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art by providing a heat pump combined with a rotary dehumidifier for heat recovery and its control method. By using a rotary dehumidifier for heat recovery, indoor energy can be recovered and the temperature and humidity of the fresh air can be regulated. At the same time, the amount of dehumidification of the heat pump circulation cooling dehumidification can be reduced, the dehumidification energy consumption of the heat pump unit can be reduced, and the energy efficiency can be further improved.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] The first aspect of this invention provides a heat pump combined with a rotor for heat recovery, a high-efficiency fresh air dehumidifier, comprising an air flow path, a rotor, and a refrigerant loop;

[0010] The airflow path includes an exhaust duct and an air supply duct that are spaced apart from each other;

[0011] The exhaust duct is equipped with a return air outlet and an exhaust air outlet at both ends;

[0012] The air supply duct is provided with an air supply outlet and a fresh air outlet at both ends;

[0013] The refrigerant loop includes a compressor, a four-way reversing valve, a first shut-off valve, an adjustable three-way valve, an exhaust coil, a fifth shut-off valve, a first throttling device, a second check valve, an air supply coil, and a third shut-off valve connected in sequence.

[0014] The rotor is vertically positioned between the exhaust duct and the supply duct, such that part of the rotor is inside the supply duct and the other part is inside the exhaust duct.

[0015] Furthermore, the upper part of the rotor is inside the air supply duct, and the lower part is inside the air exhaust duct.

[0016] Furthermore, the refrigerant loop also includes a first bypass circuit, a second bypass circuit, and a third bypass circuit;

[0017] The first bypass circuit is equipped with a reheat coil. One end of the first bypass circuit is connected to the adjustable three-way valve, and the other end is connected to the connecting pipe between the fifth shut-off valve and the first throttling device.

[0018] The second bypass circuit is provided with a fourth shut-off valve, a second throttling device, and a third check valve in sequence. One end of the second bypass circuit is connected to the air supply coil, and the other end is connected to the connecting pipe between the exhaust coil and the fifth shut-off valve.

[0019] The third bypass circuit is sequentially equipped with a second shut-off valve, a return air coil, a third throttling device, an inlet air coil, and a first one-way valve. One end of the third bypass circuit is connected to the connecting pipe between the four-way reversing valve and the first shut-off valve, and the other end is connected to the connecting pipe between the third shut-off valve and the four-way reversing valve.

[0020] Furthermore, a horizontal damper is provided between the exhaust duct and the supply duct to connect the two;

[0021] An exhaust fan is installed at the exhaust vent.

[0022] An air supply fan is installed at the air supply outlet.

[0023] Furthermore, the compressor, four-way reversing valve, first shut-off valve, adjustable three-way valve, exhaust coil, fifth shut-off valve, third shut-off valve, second shut-off valve, return air coil, third throttling device, and first one-way valve are located in the exhaust duct.

[0024] The first throttling device, the second one-way valve, the air supply coil, the reheat coil, the fourth shut-off valve, the second throttling device, the third one-way valve, and the air inlet coil are located in the air supply duct.

[0025] Furthermore, the compressor, four-way reversing valve, first shut-off valve, adjustable three-way valve, first throttling device, second check valve, air supply coil, third shut-off valve, reheat coil, fourth shut-off valve, second shut-off valve, and return air coil are located on one side of the rotor.

[0026] The exhaust coil, the fifth shut-off valve, the second throttling device, the third one-way valve, the third throttling device, and the air inlet coil are located on the other side of the rotor.

[0027] Furthermore, an air filter is provided in front of the air inlet coil, and a maintenance port is reserved on the air filter, which is located at the top of the air supply duct.

[0028] The four ports of the four-way reversing valve are respectively connected to the air supply coil, the exhaust port of the compressor, the adjustable three-way valve and the intake port of the compressor.

[0029] The three ports of the adjustable three-way valve are respectively connected to the four-way reversing valve, the exhaust coil, and the reheat coil;

[0030] The return air vent and the supply air vent are respectively equipped with a return air sensor and a supply air temperature and humidity sensor.

[0031] The return air sensor detects the temperature, humidity, and CO2 concentration in the return air;

[0032] The air supply temperature and humidity sensor detects the temperature and humidity in the air supply.

[0033] The first throttling device, the second throttling device, and the third throttling device in this technical solution are one of a capillary tube, a throttling short tube, or an electronic expansion valve. In order to facilitate the realization of automated control, this technical solution preferably uses an electronic expansion valve.

[0034] The shut-off valve in this technical solution is preferably a solenoid valve, which is suitable for the high temperature and high pressure environment of the compressor exhaust port and is conducive to the automatic control of the fresh air unit.

[0035] In this technical solution, the conduction direction of the first one-way valve is consistent with the refrigerant flow direction in the internal circulation mode, which allows the refrigerant to flow from the air inlet coil into the four-way reversing valve and to be cut off in the reverse direction.

[0036] In this technical solution, the conduction direction of the second one-way valve is consistent with the refrigerant flow direction under the summer heat recovery mode, which allows the refrigerant to flow from the first throttling device into the air supply coil and to be cut off in the reverse direction.

[0037] In this technical solution, the conduction direction of the third one-way valve is consistent with the refrigerant flow direction under the winter heat recovery mode, which allows the refrigerant to flow from the second throttling device into the exhaust coil and to be cut off in the reverse direction.

[0038] The horizontal damper described in this technical solution is a servo-driven damper, and both the exhaust vent and the inlet vent are equipped with servo-driven dampers.

[0039] A second aspect of this invention provides a control method for a heat recovery type high-efficiency fresh air dehumidifier combining a heat pump and a desiccant, as described above. Based on different operating conditions, different combinations of heat exchangers are achieved through damper opening and closing and flow path changes to reach the target supply air temperature and deep dehumidification.

[0040] In summer dehumidification mode, the air is cooled and dehumidified by the rotary wheel, then deeply dehumidified by the air supply coil, and finally reaches the target air supply temperature through the reheat coil.

[0041] In winter heating mode, the refrigerant flow path is changed, the air is heated and humidified by the rotor, and further heated to the target temperature by the air supply coil.

[0042] In internal circulation mode, the air becomes rich in moisture after passing through the impeller, increasing its humidity content. It is then cooled and dehumidified in the intake coil, reducing the enthalpy difference between the air before and after cooling and dehumidification. This effectively reduces the power consumption of the compressor while maintaining the same dehumidification capacity.

[0043] Furthermore, in the summer dehumidification mode:

[0044] The supply air vent, return air vent, fresh air vent, and exhaust air vent are all open, and the horizontal damper is closed;

[0045] Both the exhaust fan and the supply fan are turned on;

[0046] The impeller is turned on and runs at a preset high speed, which is the heat recovery mode.

[0047] The AB and CD ports of the four-way directional valve are connected;

[0048] In the adjustable three-way valve, all three ports (A, B, and C) are connected.

[0049] The first check valve is in the closed state, the second check valve is in the open state, the third check valve is in the closed state, the first shut-off valve is open, the second shut-off valve is closed, the third shut-off valve is open, the fourth shut-off valve is closed, and the fifth shut-off valve is open.

[0050] The first throttling device controls the system superheat. When the system superheat is low, the opening of the first throttling device decreases, and vice versa.

[0051] The compressor controls the indoor return air humidity through frequency regulation. When the indoor return air humidity is higher than the set value, the compressor frequency increases; when the indoor return air humidity is lower than the set value, the compressor frequency decreases.

[0052] The air supply fan controls the indoor CO2 concentration by adjusting the air supply volume. When the indoor CO2 concentration is higher than the preset value, the air supply fan speed increases and the air supply volume increases; conversely, the speed decreases.

[0053] The exhaust fan controls the amount of return air volume in the system by adjusting its speed. When the supply air volume increases, the exhaust fan increases the return air volume by increasing its speed. When the supply air volume decreases, the exhaust fan needs to reduce its speed to reduce the return air volume.

[0054] In this way, the return air volume of the system is always between 90% and 95% of the supply air volume.

[0055] Furthermore, in the winter heating mode:

[0056] All return air vents, exhaust air vents, supply air vents, and fresh air vents are open, while the horizontal dampers are closed.

[0057] Both the exhaust fan and the supply fan are turned on;

[0058] The impeller is turned on and runs at a preset high speed, which is the heat recovery mode.

[0059] The AD and BC ports of the four-way directional valve are connected.

[0060] The adjustable three-way valve has its AB ports connected and its C port closed.

[0061] The first check valve is in the closed state, the second check valve is in the closed state, and the third check valve is in the open state.

[0062] The first shut-off valve is open, the second shut-off valve is closed, the third shut-off valve is open, the fourth shut-off valve is open, and the fifth shut-off valve is closed.

[0063] The supply air temperature is controlled by adjusting the compressor frequency. When the supply air temperature is low, the compressor frequency increases, and when the supply air temperature is high, the compressor frequency decreases.

[0064] Furthermore, in the inner loop mode:

[0065] Exhaust and fresh air vents are closed, return and supply air vents are open, and horizontal dampers are open.

[0066] The exhaust fan is off, and the supply fan is on.

[0067] The dehumidifier is on, and the mode is dehumidification.

[0068] The AB ports of the four-way directional valve are connected, and the CD ports are connected.

[0069] The first check valve is in the open state, the second check valve is in the closed state, and the third check valve is in the closed state.

[0070] The first shut-off valve is closed, the second shut-off valve is open, the third shut-off valve is closed, the fourth shut-off valve is closed, and the fifth shut-off valve is closed.

[0071] The third throttling device controls the superheat of the system and controls the humidity of the indoor return air by adjusting the compressor frequency;

[0072] The blower maintains a constant speed operation;

[0073] Specifically, by opening and closing the damper and switching the flow path, this technical solution can mainly achieve the following three operating modes:

[0074] 1. Summer Dehumidification Mode: Return air vents, exhaust air vents, supply air vents, and fresh air vents are all open, while the horizontal damper is closed. Both exhaust and supply air fans are on. The deflector is on and running at high speed, in heat recovery mode. In the four-way reversing valve, the adjustable three-way valve and the compressor exhaust port are connected, and the supply coil and the compressor intake port are connected. In the adjustable three-way valve, the four-way reversing valve and the reheat coil are connected, and the four-way reversing valve and the exhaust coil are connected. The first one-way valve is in the closed state, the second one-way valve is in the open state, and the third one-way valve is in the closed state. The first stop valve is open, the second stop valve is closed, the third stop valve is open, the fourth stop valve is closed, and the fifth stop valve is open. In this mode, the first throttling device controls the system superheat, controls the indoor return air humidity through compressor frequency adjustment, and controls the supply air temperature through adjustable three-way valve opening. The indoor CO2 concentration is controlled by adjusting the supply air volume using a supply fan, and the return air volume is controlled by an exhaust fan, thereby ensuring that the system's return air volume is always between 90% and 95% of the supply air volume.

[0075] 2. Winter Heating Mode: Return air vents, exhaust air vents, supply air vents, and fresh air vents are all open, and the horizontal damper is closed. Both exhaust and supply air fans are on. The rotor is on and running at high speed, in heat recovery mode. In the four-way reversing valve, the flow paths of the supply coil and the compressor exhaust port are connected, and the flow path of the adjustable three-way valve and the compressor suction port are connected. In the adjustable three-way valve, the flow path of the four-way reversing valve and the exhaust coil is connected. The flow path of the four-way reversing valve and the reheat coil is closed. The first one-way valve is in the closed state, the second one-way valve is in the closed state, and the third one-way valve is in the open state. The first stop valve is open, the second stop valve is closed, the third stop valve is open, the fourth stop valve is open, and the fifth stop valve is closed. In this mode, the control strategies for the second throttling device, supply air fan, and exhaust air fan are the same as in dehumidification mode. The supply air temperature is controlled by adjusting the compressor frequency.

[0076] 3. Internal Circulation Mode: Exhaust and fresh air vents are closed, return and supply air vents are open, and the horizontal damper is open. The exhaust fan is off, and the supply fan is on. The dehumidifier is on and running at low speed. In the four-way reversing valve, the return air coil and the compressor exhaust port are connected, and the intake coil and the compressor suction port are connected. The first one-way valve is in the open state, the second one-way valve is in the closed state, and the third one-way valve is in the closed state. The first stop valve is closed, the second stop valve is open, the third stop valve is closed, the fourth stop valve is closed, and the fifth stop valve is closed. In this mode, the third throttling device controls the system superheat and controls the indoor return air humidity through compressor frequency adjustment. The supply fan maintains a constant speed operation.

[0077] In this technical solution, a control method for a heat pump combined with a rotary dehumidifier for high-efficiency fresh air dehumidification is described. In summer dehumidification mode, the refrigerant in the supply coil evaporates and absorbs heat to become refrigerant gas. This gas is then drawn into the compressor inlet via a four-way reversing valve and compressed into high-temperature, high-pressure refrigerant gas. The refrigerant then passes through the four-way reversing valve and an adjustable three-way valve for diversion. It condenses and releases heat in the exhaust coil and reheat coil. After merging, it passes through a first throttling device to become a gas-liquid two-phase state, and then returns to the supply coil via a second one-way valve. Outdoor fresh air enters the supply air duct from the fresh air inlet, is first filtered by an air filter, then passes through the rotary dehumidifier to exchange heat and humidity with the indoor return air, resulting in a decrease in both temperature and humidity. Finally, it is cooled and dehumidified by the supply coil and reheated by the reheat coil before entering the room through the supply air inlet. Indoor return air enters the exhaust duct through the return air vent, first carrying away some of the heat dissipated by the compressor. After passing through a rotary drum and exchanging heat and humidity with fresh air, both temperature and humidity increase. Then, it absorbs heat again through the exhaust coil and is finally discharged outdoors through the exhaust vent by the exhaust fan. In this mode, the first throttling device controls the system's superheat. When the system superheat is low, the opening of the second throttling device decreases, and vice versa. The compressor controls the indoor return air humidity through frequency regulation. When the indoor return air humidity is higher than the set value, the compressor frequency increases; when the indoor return air humidity is lower than the set value, the compressor frequency decreases. The supply fan controls the indoor CO2 concentration by adjusting the airflow. When the indoor CO2 concentration is high, the supply fan speed increases, and the airflow increases; conversely, the speed decreases. The exhaust fan controls the return air volume of the system by adjusting its speed. When the supply air volume increases, the exhaust fan increases its speed to increase the return air volume; conversely, when the supply air volume decreases, the exhaust fan needs to decrease its speed to reduce the return air volume. In this way, the system's return air volume is always maintained between 90% and 95% of the supply air volume.

[0078] In this technical solution, a control method for a heat pump combined with a rotary dehumidifier for high-efficiency fresh air dehumidification is described. In winter heating mode, the refrigerant in the exhaust coil evaporates and absorbs heat, becoming a refrigerant gas. This gas is then drawn into the compressor inlet via an adjustable three-way valve and a four-way reversing valve, where it is compressed into a high-temperature, high-pressure refrigerant gas. It then condenses and releases heat in the supply coil via the four-way reversing valve. After passing through a second throttling device, it becomes a gas-liquid two-phase state and returns to the exhaust coil via a third one-way valve. Outdoor fresh air enters the supply duct from the fresh air inlet, is first filtered by an air filter, and then exchanges heat and humidity with the indoor return air via the rotary dehumidifier, increasing both temperature and humidity. After absorbing heat again in the supply coil, it enters the room through the supply air inlet. Indoor return air enters the exhaust duct from the return air inlet, first carrying away some of the heat dissipated by the compressor. After exchanging heat and humidity with the fresh air via the rotary dehumidifier, both temperature and humidity decrease. It then passes through the exhaust coil for further cooling and is finally discharged outdoors through the exhaust fan. In this mode, the control strategies for the second throttling device, supply fan, and exhaust fan are the same as in the summer dehumidification mode. The supply air temperature is controlled by adjusting the compressor frequency; when the supply air temperature is low, the compressor frequency increases, and when the supply air temperature is high, the compressor frequency decreases.

[0079] In this technical solution, a control method for a heat pump combined with a rotary dehumidifier for high-efficiency fresh air dehumidification is described. In internal circulation mode, refrigerant evaporates and absorbs heat in the inlet coil, becoming refrigerant gas. This gas is then drawn into the compressor inlet via a first one-way valve and a four-way reversing valve, where it is compressed into high-temperature, high-pressure refrigerant gas. It then condenses and releases heat in the supply coil via the four-way reversing valve, and finally returns to the inlet coil as a gas-liquid two-phase state after passing through a third throttling device. Indoor return air enters the exhaust duct from the return air vent, first carrying away some of the heat dissipated by the compressor. It then absorbs heat in the return coil, then absorbs moisture and releases heat in the rotary regeneration zone, and enters the supply duct through a horizontal damper. It is filtered by an air filter, cooled and dehumidified in the inlet coil, and further dehumidified and heat-absorbing in the rotary dehumidification zone before entering the room through the supply air vent. In this mode, the third throttling device controls the system superheat, and the indoor return air humidity is controlled by adjusting the compressor frequency. The supply fan maintains a constant speed operation.

[0080] The rotary dehumidifier combined with heat pump heat recovery and its control method in this invention have the following advantages and innovations compared with the prior art:

[0081] 1. Utilizing a rotary wheel to recover indoor energy, the system reduces air temperature and humidity in summer heat recovery mode, thereby reducing the cooling and dehumidification load of the heat pump unit and lowering compressor power consumption; in winter heat recovery mode, it heats the air, reducing the heating capacity of the heat pump unit, lowering power consumption, and simultaneously increasing air humidity to improve comfort; in internal circulation mode, it enriches moisture, reduces the enthalpy difference between the air before and after cooling and dehumidification, and improves dehumidification efficiency.

[0082] 2. The rotor in this technical solution is a heat recovery rotor with adjustable speed, offering both high and low speed operating modes. At high speed, the rotor performs heat recovery; at low speed, it performs dehumidification. The internal circulation mode of this technical solution has a low dehumidification load; by adjusting the rotor speed, the heat recovery rotor can be used to achieve the dehumidification function. This increases the utilization rate of the rotor under different operating conditions and allows a single rotor to perform two functions, reducing unit costs.

[0083] 3. By using a heat pump unit to replace the electric heating system of a traditional rotary dehumidifier, the dehumidifier's dehumidification capacity is regenerated in internal circulation mode, achieving moisture enrichment in the lower half of the dehumidifier and deep dehumidification in the upper half. This reduces system power consumption while improving dehumidification efficiency.

[0084] 4. A first bypass circuit is provided. In summer heat recovery mode, the reheat coil and exhaust coil are connected in parallel using an adjustable three-way valve. By adjusting the opening of the three-way valve, the refrigerant flow in the reheat coil is controlled, thereby controlling the air reheat temperature and achieving precise regulation of the supply air temperature. In particular, it can meet the requirement of a minimum supply air temperature of 22℃ in the new national standard.

[0085] 5. A third bypass circuit is provided. Through the one-way conduction of the first one-way valve, the refrigerant does not flow into the third bypass circuit in the winter heat recovery mode, which effectively avoids the loss of heat of indoor return air in the return air coil and improves the heat recovery.

[0086] 6. In this technical solution, the refrigerant loop is equipped with three bypass loops, and the inlet coil, supply coil, reheat coil, return coil and exhaust coil are combined and connected through valves. By using different heat exchanger combinations, the air temperature and humidity can be precisely regulated under different operating modes.

[0087] 7. The unit in this technical solution has multiple adjustable modes, and all of them can maintain the indoor temperature and humidity at the set value through mutual control between the components, which not only makes it convenient for users to use, but also improves the comfort of users. Attached Figure Description

[0088] Figure 1 This is a schematic diagram of the structure of the heat recovery type high-efficiency fresh air dehumidifier combining heat pump and rotor in this invention;

[0089] Figure 2 This is a schematic diagram of the process of the heat recovery type high-efficiency fresh air dehumidifier with heat pump and rotor in the summer dehumidification mode of the present invention;

[0090] Figure 3 This is a schematic diagram of the process of the heat recovery type high-efficiency fresh air dehumidifier with heat pump and rotor in the winter heating mode of the present invention;

[0091] Figure 4 This is a schematic diagram of the heat recovery type high-efficiency fresh air dehumidifier with heat pump and impeller in the internal circulation mode of the present invention.

[0092] In the diagram: 1-Supply air duct; 2-Exhaust air duct; 3-Supply air outlet; 4-Return air outlet; 5-Fresh air outlet; 6-Exhaust air outlet; 7-Horizontal damper; 8~10 Air valves; 11-Inlet coil; 12-Supply air coil; 13-Reheat coil; 14-Return air coil; 15-Exhaust air coil; 16-Air filter; 17-Compressor; 18-Four-way reversing valve; 19-First check valve; 20-Second check valve; 21-Third check valve; 22-Adjustable three-way valve; 23-First throttling device; 24-Second throttling device; 25-Third throttling device; 26-First shut-off valve; 27-Second shut-off valve; 28-Third shut-off valve; 29-Fourth shut-off valve; 30-Fifth shut-off valve; 31-Rotator; 32-Exhaust fan; 33-Supply air fan; 34~60 Connecting pipes. Detailed Implementation

[0093] In terms of overall design, this invention internally incorporates a rotary drum, inlet coil, supply coil, reheat coil, return coil, and exhaust coil. Different combinations of heat exchangers can be achieved by opening and closing dampers and changing the flow path according to different operating conditions, thus reaching the target supply air temperature and achieving deep dehumidification. In summer dehumidification mode, air is cooled and dehumidified by the rotary drum, then deeply dehumidified in the supply coil, and finally reaches the target supply air temperature through the reheat coil. In winter heating mode, the refrigerant flow path is changed; air is heated and humidified by the rotary drum, and further heated to the target temperature in the supply coil. In internal circulation mode, air becomes enriched with moisture after passing through the rotary drum, increasing its humidity content. Cooling and dehumidification then occurs in the inlet coil, reducing the enthalpy difference between the air before and after cooling and dehumidification, effectively reducing compressor power consumption for the same dehumidification capacity.

[0094] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Any structural / module names, control modes, algorithms, processes, or composition ratios not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0095] Example 1

[0096] This embodiment describes a heat pump combined with a rotary dehumidifier for heat recovery, a high-efficiency fresh air dehumidifier with the following structure: Figure 1As shown, it mainly includes: air supply duct 1, air exhaust duct 2, air supply outlet 3, air return outlet 4, fresh air outlet 5, air exhaust outlet 6, horizontal damper 7, air valves 8-10, air inlet coil 11, air supply coil 12, reheat coil 13, air return coil 14, air exhaust coil 15, air filter 16, compressor 17, four-way reversing valve 18, first one-way valve 19, second one-way valve 20, third one-way valve 21, adjustable three-way valve 22, first throttling device 23, second throttling device 24, third throttling device 25, first shut-off valve 26, second shut-off valve 27, third shut-off valve 28, fourth shut-off valve 29, fifth shut-off valve 30, impeller 31, exhaust fan 32, air supply fan 33, and connecting pipes 34-60.

[0097] In this embodiment, compressor 17, connecting pipe 34, four-way reversing valve 18, connecting pipes 40 and 41, first shut-off valve 26, connecting pipe 44, adjustable three-way valve 22, connecting pipe 47, exhaust coil 15, connecting pipes 49 and 50, fifth shut-off valve 30, connecting pipes 53 and 57, first throttling device 23, connecting pipe 58, second one-way valve 20, connecting pipe 59, supply coil 12, connecting pipe 39, third shut-off valve 28, connecting pipes 37 and 36, four-way reversing valve 18, and connecting pipe 35 are connected sequentially to form a refrigerant loop. Specifically, interface A of the four-way reversing valve 18 is connected to connecting pipe 36, interface B is connected to connecting pipe 35, interface C is connected to connecting pipe 40, and interface D is connected to connecting pipe 34.

[0098] In this embodiment, the refrigerant loop also includes a first bypass loop, a second bypass loop, and a third bypass loop. The first bypass loop consists of a connecting pipe 46, a reheat coil 13, and a connecting pipe 56. One end of the first bypass loop is connected to the adjustable three-way valve 22 via the connecting pipe 46, and the other end is connected to the connecting pipes 53 and 57 between the fifth shut-off valve 30 and the first throttling device 23 via the connecting pipe 56. The second bypass loop consists of a connecting pipe 60, a fourth shut-off valve 29, a connecting pipe 54, a second throttling device 24, a connecting pipe 52, a third one-way valve 21, and a connecting pipe 51. One end of the second bypass loop is connected to the supply coil 12 via the connecting pipe 60, and the other end is connected to the connecting pipes 49 and 50 between the exhaust coil 15 and the fifth shut-off valve 30 via the connecting pipe 51. The third bypass circuit consists of connecting pipe 42, second shut-off valve 27, connecting pipe 43, return air coil 14, connecting pipe 45, third throttling device 25, connecting pipe 48, air inlet coil 11, connecting pipe 55, first one-way valve 19, and connecting pipe 38. One end of the circuit is connected to connecting pipes 40 and 41 between four-way reversing valve 18 and first shut-off valve 26 via connecting pipe 42, and the other end is connected to connecting pipes 36 and 37 between third shut-off valve 28 and four-way reversing valve 18 via connecting pipe 38.

[0099] This unit can achieve the following three operating modes by opening and closing dampers and switching flow paths:

[0100] I. Summer Dehumidification Mode (see Figure 2 )

[0101] In this embodiment, during the summer dehumidification mode, the following components are in operation: Supply air vent 3, return air vent 4, fresh air vent 5, and exhaust air vent 6 are all open; horizontal damper 7 is closed. Exhaust fan 32 and supply air fan 33 are both on. Rotor 31 is on and running at high speed in heat recovery mode. The AB and CD ports of the four-way reversing valve 18 are connected. In the adjustable three-way valve 22, all three ports (A, B, and C) are connected. The first one-way valve 19 is in the closed state, the second one-way valve 20 is in the open state, and the third one-way valve 21 is in the closed state. The first stop valve 26 is open, the second stop valve 27 is closed, the third stop valve 28 is open, the fourth stop valve 29 is closed, and the fifth stop valve 30 is open.

[0102] In the summer dehumidification mode of this embodiment, the refrigerant flow path is as follows: the refrigerant in the supply coil 12 evaporates and absorbs heat to become refrigerant gas. It is then drawn into the suction port of the compressor 17 via the four-way reversing valve 18 and compressed into high-temperature and high-pressure refrigerant gas. The refrigerant then passes through the four-way reversing valve 18 and is split by the adjustable three-way valve 22. It condenses and releases heat in the exhaust coil 15 and the reheat coil 13. After merging, it passes through the first throttling device 23 and becomes a gas-liquid two-phase state. Then, it returns to the supply coil 12 via the second one-way valve 20.

[0103] In this embodiment, during the summer dehumidification mode, the airflow path is as follows: Outdoor fresh air enters the supply air duct 1 from the fresh air inlet 5, is first filtered by the air filter 16, then exchanges heat and humidity with the indoor return air through the impeller 31, resulting in a decrease in both temperature and humidity. Finally, it is cooled and dehumidified by the supply air coil 12 and reheated by the reheat coil 13 before entering the room through the supply air inlet 3. Indoor return air enters the exhaust air duct 2 from the return air inlet 4, first carrying away some of the heat emitted by the compressor 17, then exchanges heat and humidity with the fresh air through the impeller 31, resulting in an increase in both temperature and humidity. It then absorbs heat through the exhaust coil 15 and is finally discharged outdoors through the exhaust air outlet 6 by the exhaust fan 32.

[0104] In this embodiment, the unit's control strategy in summer dehumidification mode is as follows: The first throttling device 23 controls the system superheat. When the system superheat is low, the opening of the first throttling device 23 decreases, and vice versa. The compressor 17 controls the indoor return air humidity through frequency regulation. When the indoor return air humidity is higher than the set value, the compressor 17 frequency increases; when the indoor return air humidity is lower than the set value, the compressor 17 frequency decreases. The supply fan 33 controls the indoor CO2 concentration by adjusting the supply air volume. When the indoor CO2 concentration is high, the supply fan 33 speed increases, and the supply air volume increases; conversely, the speed decreases. The exhaust fan 32 controls the system return air volume by adjusting its speed. When the supply air volume of the supply fan 33 increases, the exhaust fan 32 increases the return air volume by increasing its speed; when the supply air volume of the supply fan 33 decreases, the exhaust fan 32 needs to decrease its speed to reduce the return air volume. In this way, the return air volume of the system is always between 90% and 95% of the supply air volume.

[0105] II. Winter Heating Mode (see below) Figure 3 )

[0106] In this embodiment, during winter heating mode, the following components are in operation: return air vent 4, exhaust air vent 6, supply air vent 3, and fresh air vent 5 are all open, while the horizontal damper 7 is closed. Exhaust fan 32 and supply fan 33 are both on. Rotor 31 is on and running at high speed in heat recovery mode. The AD and BC ports of the four-way reversing valve 18 are connected. The AB ports of the adjustable three-way valve 22 are connected, and the C port is closed. The first one-way valve 19 is in the closed state, the second one-way valve 20 is in the closed state, and the third one-way valve 21 is in the open state. The first stop valve 26 is open, the second stop valve 27 is closed, the third stop valve 28 is open, the fourth stop valve 29 is open, and the fifth stop valve 30 is closed.

[0107] In the winter heating mode of this embodiment, the refrigerant flow path is as follows: the refrigerant in the exhaust coil 15 evaporates and absorbs heat to become a refrigerant gas. It is then drawn into the suction port of the compressor 17 and compressed into a high-temperature and high-pressure refrigerant gas through the adjustable three-way valve 22 and the four-way reversing valve 18. It then condenses and releases heat in the supply coil 12 through the four-way reversing valve 18. After passing through the second throttling device 24, it becomes a gas-liquid two-phase state and returns to the exhaust coil 15 through the third one-way valve 21.

[0108] In the winter heating mode of this embodiment, the airflow path is as follows: Outdoor fresh air enters the supply air duct 1 from the fresh air inlet 5, is first filtered by the air filter 16, and then exchanges heat and humidity with the indoor return air through the impeller 31, resulting in an increase in both temperature and humidity. After absorbing heat through the supply air coil 12, it enters the room through the supply air inlet 3. Indoor return air enters the exhaust air duct 2 from the return air inlet 4, first carrying away some of the heat emitted by the compressor 17, then exchanges heat and humidity with the fresh air through the impeller 31, resulting in a decrease in both temperature and humidity. It then passes through the exhaust air coil 15 for further cooling, and finally passes through the exhaust fan 32 and is discharged outdoors through the exhaust air outlet 6.

[0109] In the winter heating mode of this embodiment, the control strategy is as follows: In this mode, the control strategies for the second throttling device 24, the supply fan 33, and the exhaust fan 32 are the same as in the dehumidification mode. The supply air temperature is controlled by adjusting the frequency of the compressor 17. When the supply air temperature is low, the frequency of the compressor 17 increases; when the supply air temperature is high, the frequency of the compressor 17 decreases.

[0110] III. Internal Circulation Mode (see...) Figure 4 )

[0111] In this embodiment, under internal circulation mode, the following component states are observed: exhaust vent 6 and fresh air vent 5 are closed; return air vent 4 and supply air vent 3 are open; and horizontal damper 7 is open. Exhaust fan 32 is closed, and supply fan 33 is on. Rotor 31 is on and operates at low speed in dehumidification mode. The AB and CD interfaces of the four-way reversing valve 18 are connected. The first one-way valve 19 is in the conducting state, the second one-way valve 20 is in the closed state, and the third one-way valve 21 is in the closed state. The first stop valve 26 is closed, the second stop valve 27 is open, the third stop valve 28 is closed, the fourth stop valve 29 is closed, and the fifth stop valve 30 is closed. In this mode, the third throttling device 25 controls the system superheat and regulates the indoor return air humidity through compressor 17 frequency adjustment. Supply fan 33 maintains constant speed operation.

[0112] In the internal circulation mode of this embodiment, the refrigerant flow path is as follows: the refrigerant evaporates and absorbs heat in the inlet coil 11 to become refrigerant gas, which is then drawn into the suction port of the compressor 17 through the first one-way valve 19 and the four-way reversing valve 18 and compressed into high-temperature and high-pressure refrigerant gas. After passing through the four-way reversing valve 18, it condenses and releases heat in the outlet coil 12, and returns to the inlet coil 11 after passing through the third throttling device 25 to become a gas-liquid two-phase state.

[0113] In the internal circulation mode of this embodiment, the air flow path is as follows: indoor return air enters the exhaust duct 2 from the return air vent 4, first taking away some of the heat emitted by the compressor 17, then absorbing heat through the return air coil 14, then absorbing moisture and releasing heat through the regeneration zone of the rotor 31, and then entering the supply air duct 1 through the horizontal damper 7. It is filtered by the air filter 16, cooled and dehumidified by the intake air coil 11, and then further dehumidified and absorbed heat through the dehumidification zone of the rotor 31 before entering the room through the supply air vent 3.

[0114] In this embodiment, the unit operates in internal circulation mode. The control strategy is as follows: In this mode, the third throttling device 25 controls the system superheat, and the compressor 17 regulates the indoor return air humidity. The supply fan 33 maintains a constant speed operation.

[0115] It should be stated that other arrangements based on the principles of this invention are also within the scope of protection of this invention.

[0116] The terms "first" and "second" are used in this document to define components. Those skilled in the art should understand that the use of these terms is solely for the purpose of distinguishing components in description. Unless otherwise stated, these terms have no special meaning.

[0117] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A heat recovery type fresh air dehumidifier combining a heat pump and a desiccant, characterized in that, Includes airflow path, impeller (31), and refrigerant loop; The airflow path includes an exhaust duct (2) and an air supply duct (1) spaced apart from each other. The exhaust duct (2) is provided with a return air inlet (4) and an exhaust air inlet (6) at both ends; The air supply duct (1) is provided with an air supply outlet (3) and a fresh air outlet (5) at both ends; A horizontal damper (7) is provided between the exhaust duct (2) and the supply duct (1) to connect the two. The refrigerant loop includes a compressor (17), a four-way reversing valve (18), a first shut-off valve (26), an adjustable three-way valve (22), an exhaust coil (15), a fifth shut-off valve (30), a first throttling device (23), a second check valve (20), an air supply coil (12), and a third shut-off valve (28) connected in sequence. The rotor (31) is vertically arranged between the exhaust duct (2) and the supply duct (1), so that part of the rotor (31) is in the supply duct (1) and the other part is in the exhaust duct (2). In this way, the rotor (31) is used to recover heat, which not only recovers indoor energy and regulates the temperature and humidity of fresh air, but also reduces the amount of dehumidification of the refrigerant loop cooling and dehumidification, and reduces the dehumidification energy consumption of the refrigerant loop. The refrigerant loop further includes a first bypass loop, a second bypass loop, and a third bypass loop; The first bypass circuit is provided with a reheat coil (13), one end of the first bypass circuit is connected to the adjustable three-way valve (22), and the other end is connected to the connecting pipe between the fifth shut-off valve (30) and the first throttling device (23); The second bypass circuit is provided with a fourth shut-off valve (29), a second throttling device (24), and a third check valve (21) in sequence. One end of the second bypass circuit is connected to the air supply coil (12), and the other end is connected to the connecting pipe between the exhaust coil (15) and the fifth shut-off valve (30). The third bypass circuit is provided with a second shut-off valve (27), a return air coil (14), a third throttling device (25), an air inlet coil (11), and a first one-way valve (19) in sequence. One end of the third bypass circuit is connected to the connecting pipe between the four-way reversing valve (18) and the first shut-off valve (26), and the other end is connected to the connecting pipe between the third shut-off valve (28) and the four-way reversing valve (18).

2. The heat recovery type fresh air dehumidifier combining a heat pump and a rotor according to claim 1, characterized in that, An exhaust fan (32) is provided at the exhaust vent (6); A blower (33) is provided at the air outlet (3).

3. A heat pump combined with a rotor heat recovery type fresh air dehumidifier according to claim 1, characterized in that, The compressor (17), four-way reversing valve (18), first shut-off valve (26), adjustable three-way valve (22), exhaust coil (15), fifth shut-off valve (30), third shut-off valve (28), second shut-off valve (27), return air coil (14), third throttling device (25), and first one-way valve (19) are located in the exhaust duct (2); The first throttling device (23), the second one-way valve (20), the air supply coil (12), the reheat coil (13), the fourth shut-off valve (29), the second throttling device (24), the third one-way valve (21), and the air inlet coil (11) are located in the air supply duct (1).

4. A heat pump combined with a rotor heat recovery type fresh air dehumidifier according to claim 1, characterized in that, The compressor (17), four-way reversing valve (18), first shut-off valve (26), adjustable three-way valve (22), first throttling device (23), second check valve (20), air supply coil (12), third shut-off valve (28), reheat coil (13), fourth shut-off valve (29), second shut-off valve (27), and return air coil (14) are located on one side of the rotor (31); The exhaust coil (15), the fifth shut-off valve (30), the second throttling device (24), the third one-way valve (21), the third throttling device (25), and the air inlet coil (11) are located on the other side of the rotor (31).

5. A heat pump combined with a rotor heat recovery type fresh air dehumidifier according to claim 1, characterized in that, An air filter (16) is provided in front of the air inlet coil (11), and a repair port is reserved on the air filter (16). The repair port is located at the top of the air supply duct (1). The four ports of the four-way reversing valve (18) are respectively connected to the exhaust port of the air supply coil (12), the compressor (17), the adjustable three-way valve (22), and the intake port of the compressor (17); The three ports of the adjustable three-way valve (22) are respectively connected to the four-way reversing valve (18), the exhaust coil (15), and the reheat coil (13); The return air inlet (4) and the supply air inlet (3) are respectively equipped with a return air sensor and a supply air temperature and humidity sensor; The return air sensor detects the temperature, humidity, and CO2 concentration in the return air; The air supply temperature and humidity sensor detects the temperature and humidity in the air supply.

6. A control method for a heat recovery type fresh air dehumidifier combining a heat pump and a rotor as described in any one of claims 1 to 5, characterized in that, include: Depending on different operating conditions, different combinations of heat exchangers are achieved by opening and closing dampers and changing the flow path to reach the target supply air temperature and deep dehumidification. In summer dehumidification mode, after the air is cooled and dehumidified by the rotor (31), it is deeply dehumidified in the air supply coil (12) and finally reaches the target air supply temperature through the reheat coil (13); In winter heating mode, the refrigerant flow path is changed, the air is heated and humidified by the impeller (31), and further heated to the target temperature by the air supply coil (12); In the internal circulation mode, the air is enriched with moisture after passing through the impeller (31), and the moisture content increases. It is then cooled and dehumidified in the air inlet coil (11), which reduces the enthalpy difference of the air before and after cooling and dehumidification, and effectively reduces the power consumption of the compressor under the same dehumidification capacity.

7. The control method for a heat recovery type fresh air dehumidifier combining a heat pump and a rotor according to claim 6, characterized in that, In the summer dehumidification mode: The supply air vent (3), return air vent (4), fresh air vent (5), and exhaust air vent (6) are all open, and the horizontal damper (7) is closed; Both the exhaust fan (32) and the supply fan (33) are turned on; The rotor (31) is turned on and runs at a preset high speed, which is the heat recovery mode; The AB port of the four-way reversing valve (18) is connected, and the CD port is connected; In the adjustable three-way valve (22), all three ports A, B, and C are connected; The first check valve (19) is in the closed state, the second check valve (20) is in the open state, the third check valve (21) is in the closed state, the first stop valve (26) is open, the second stop valve (27) is closed, the third stop valve (28) is open, the fourth stop valve (29) is closed, and the fifth stop valve (30) is open. The first throttling device (23) controls the system superheat. When the system superheat is low, the opening of the first throttling device (23) decreases, and vice versa. The compressor (17) controls the indoor return air humidity through frequency regulation. When the indoor return air humidity is greater than the set value, the compressor (17) frequency increases. When the indoor return air humidity is lower than the set value, the compressor (17) frequency decreases. The air supply fan (33) controls the indoor CO2 concentration by adjusting the air supply volume. When the indoor CO2 concentration is higher than the preset value, the air supply fan (33) speed increases and the air supply volume increases; conversely, the speed decreases. The exhaust fan (32) controls the amount of return air volume of the system by adjusting the speed. When the supply air volume of the supply fan (33) increases, the exhaust fan (32) increases the return air volume by increasing the speed. When the supply air volume of the supply fan (33) decreases, the exhaust fan (32) needs to reduce the speed to reduce the return air volume. In this way, the return air volume of the system is always between 90% and 95% of the supply air volume.

8. The control method for a heat recovery type fresh air dehumidifier combining a heat pump and a rotor according to claim 6, characterized in that, In the winter heating mode: Return air vent (4), exhaust air vent (6), supply air vent (3), and fresh air vent (5) are all open, while the horizontal damper (7) is closed; Both the exhaust fan (32) and the supply fan (33) are turned on; The rotor (31) is turned on and runs at a preset high speed, which is the heat recovery mode; The AD port of the four-way reversing valve (18) is connected, and the BC port is connected; The AB ports of the adjustable three-way valve (22) are connected, and the C port is closed; The first check valve (19) is in the closed state, the second check valve (20) is in the closed state, and the third check valve (21) is in the open state. The first shut-off valve (26) is open, the second shut-off valve (27) is closed, the third shut-off valve (28) is open, the fourth shut-off valve (29) is open, and the fifth shut-off valve (30) is closed. The supply air temperature is controlled by adjusting the frequency of the compressor (17). When the supply air temperature is low, the frequency of the compressor (17) increases, and when the supply air temperature is high, the frequency of the compressor (17) decreases.

9. The control method for a heat recovery type fresh air dehumidifier combining a heat pump and a rotor according to claim 6, characterized in that, In the inner loop mode: The exhaust vent (6) and fresh air vent (5) are closed, the return air vent (4) and supply air vent (3) are open, and the horizontal damper (7) is open; The exhaust fan (32) is turned off, and the supply fan (33) is turned on; The rotor (31) is turned on and runs at a preset low speed setting in dehumidification mode. The AB ports of the four-way directional valve (18) are connected, and the CD ports are connected; The first check valve (19) is in the open state, the second check valve (20) is in the closed state, and the third check valve (21) is in the closed state. The first shut-off valve (26) is closed, the second shut-off valve (27) is open, the third shut-off valve (28) is closed, the fourth shut-off valve (29) is closed, and the fifth shut-off valve (30) is closed. The third throttling device (25) controls the superheat of the system and controls the humidity of the indoor return air by adjusting the frequency of the compressor (17); The blower (33) maintains a constant speed operation.

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