Heat pump type temperature and humidity adjusting unit and control method thereof

Abstract

The invention relates to a heat pump type temperature and humidity adjusting unit and a control method thereof, and belongs to the field of electric heat and humidity control. The heat pump type temperature and humidity adjusting unit comprises a compressor (1) with a middle air supply port, a four-way reversing valve (2), a gas-liquid separator (12), a flash tank (10), a first heat exchanger (4), a second heat exchanger (6), a third heat exchanger (8), a fourth heat exchanger (9), a first electromagnetic valve (3), a second electromagnetic valve (5), a first expansion valve (7), a second expansion valve (11) and a refrigerant pipeline. Freezing dehumidification, ultrasonic humidification and condensation heat adjustable recovery are adopted in an air supply loop, so that accurate control over the air supply temperature and humidity is achieved.

Description

Technical Field

[0001] The invention belongs to the field of electrical heat and humidity control, and in particular relates to a heat pump type temperature and humidity control unit and a control method thereof. Background Art

[0002] The internal space of the switch cabinet and terminal box of the substation is small, relatively closed, and the air circulation is not smooth. Moisture often enters due to poor sealing and underground moisture. When the air humidity is too high, condensation is easy to occur in the cabinet, causing the insulation parts to be damp, which reduces the performance and life of the components, accelerates metal corrosion, oxidizes the contact surface, increases the contact resistance, and seriously reduces the insulation strength, which leads to accidents. At the same time, there are heat sources in the switch cabinet and terminal cabinet, which will cause high temperature inside when exposed to high temperature in summer, seriously affecting the reliable operation of the equipment in the cabinet and accelerating the aging of the equipment. Therefore, moisture prevention, dehumidification and temperature control have become important issues restricting the safe and stable operation of the switch cabinet.

[0003] According to the mechanism of condensation generation, the dehumidification methods currently used in switch cabinets and terminal boxes are: forced ventilation, electric heating, dehumidifier, etc.

[0004] (1) Heating method and heating type dehumidification increase the temperature inside the cabinet to ensure that the temperature inside the cabinet is always higher than the ambient temperature outside the cabinet, thereby suppressing the formation of condensation.

[0005] (2) Ventilation and ventilation dehumidification methods reduce the humidity inside electrical equipment by exchanging air convection with dry air from the outside.

[0006] (3) Drying method: Hang a desiccant bag on the cabinet to absorb moisture inside the cabinet, reduce the humidity inside the cabinet, and avoid the formation of condensation.

[0007] (4) The dehumidifier uses semiconductor refrigeration technology to create condensation conditions locally, so that the humid air in the cabinet condenses into water and is directly discharged out of the cabinet, thereby reducing the relative humidity of the air in the cabinet, solving the internal humidity of electrical equipment, and inhibiting the occurrence of condensation.

[0008] (5) Outdoor cabinet air conditioners are mainly used to remove the heat generated by the electrical components consuming electricity, providing an ideal temperature and humidity environment for the interior of various cabinets. At the same time, they isolate dust and corrosive gases in the external environment, extend the service life of electrical components, and improve the reliability of machine system operation.

[0009] At present, the thermal and humid environment control inside electrical switch cabinets, terminal boxes and control cabinets is mainly based on cooling and dehumidification. The outdoor cabinet air conditioners currently used use refrigeration and dehumidification to cool and dehumidify the cabinets. They have a single function. Usually, the refrigeration system only has cooling and dehumidification functions, and heating and humidification are mainly based on cold and heat offset, which has high energy consumption. Moreover, due to the mutual coupling of humid air temperature and humidity, it is difficult to accurately control the temperature and humidity in the cabinet, resulting in limited adaptability of its application. Under the conditions of high precision requirements for temperature and humidity control and wide-area adaptation needs, outdoor cabinet air conditioners are difficult to meet the application requirements of cabinet efficiency, constant temperature and humidity. Summary of the invention

[0010] The purpose of the present invention is to provide a heat pump type temperature and humidity control unit and a control method thereof. Through the heat pump type temperature and humidity control unit, refrigeration dehumidification, ultrasonic humidification and condensation heat adjustable recovery technology are used in the air supply circuit to accurately control the supply air temperature and humidity, so as to achieve the purpose of high-precision control of the temperature and humidity inside the cabinet; at the same time, a heat pump scheme is adopted, and the heating, cooling and dehumidification functions of the supply air parameters can be realized by switching the four-way reversing valve; a double throttling quasi-two-stage compression scheme is adopted to improve the adaptability of the temperature and humidity control unit to working conditions, especially to extreme working conditions, which can effectively improve the operating performance and energy efficiency of the unit; by recovering the condensed water in the evaporator dehumidification process, the humidification function is realized by using ultrasonic atomization and condenser reheating, and the condensed water discharge problem is solved; because the air temperature and humidity are controlled in series by the evaporator refrigeration dehumidification and the adjustable condenser and ultrasonic humidification, the decoupling control of the supply air temperature and humidity can be realized, and the mutual coupling influence of the temperature and humidity control processes can be avoided.

[0011] A heat pump type temperature and humidity control unit comprises a compressor with an intermediate air supply port (1), a four-way reversing valve (2), a gas-liquid separator (12), a flasher (10), a first heat exchanger (4), a second heat exchanger (6), a third heat exchanger (8), a fourth heat exchanger (9), a first solenoid valve (3), a second solenoid valve (5), a first expansion valve (7), a second expansion valve (11) and a refrigerant pipeline.

[0012] Optionally, the air processing loop of the heat pump type temperature and humidity control unit is as follows: the return air is delivered in sequence through the third heat exchanger (8), the fourth heat exchanger (9), the ultrasonic humidifier (14) and the first heat exchanger (4) along the air flow direction.

[0013] Optionally, the heat pump type temperature and humidity control unit includes a cooling and dehumidification mode and a heating and humidification operation mode.

[0014] Optionally, the cooling and dehumidification mode is:

[0015] The exhaust port (1-1) of the compressor (1) is connected to the port (2-1) of the four-way reversing valve (2) through a high-pressure gaseous refrigerant pipeline, the port (2-1) of the four-way reversing valve (2) is connected to the port (2-2), the port (2-2) of the four-way reversing valve (2) is connected in parallel to the inlets of the first solenoid valve (3) and the second solenoid valve (5) through the high-pressure refrigerant pipeline, the outlet of the first solenoid valve (3) is connected to the inlet (4-1) of the first heat exchanger (4) through the refrigerant pipeline, the outlet of the second solenoid valve (5) is connected to the inlet (6-1) of the second heat exchanger (6), the second heat exchanger (6) is placed outdoors, the outlet (4-2) of the first heat exchanger (4) and the outlet (6-2) of the second heat exchanger (6) are connected in parallel to the inlet of the first expansion valve (7) through the high-pressure liquid refrigerant pipeline, and the outlet of the first expansion valve (7) is connected to the inlet of the third expansion valve (7). The inlet (8-1) of the heat exchanger (8) is connected, the outlet (8-2) of the third heat exchanger (8) is connected to the (10-2) port of the flasher (10), the (10-3) port of the flasher (10) is connected to the inlet of the second expansion valve (11), the (10-1) port of the flasher (10) is connected to the intermediate air supply port (1-3) port of the compressor (1), the outlet of the second expansion valve (11) is connected to the inlet (9-1) of the fourth heat exchanger (9), the outlet (9-2) of the fourth heat exchanger (9) is connected to the (2-3) port of the four-way reversing valve (2), the (2-3) port of the four-way reversing valve is connected to the (2-4) port, the (2-4) port is connected to the inlet of the gas-liquid separator (12), and the outlet of the gas-liquid separator (12) is connected to the low-pressure air intake port (1-2) of the compressor (1), thereby completing the circulation process of the refrigerant.

[0016] Optionally, the heating and humidification operation mode is:

[0017] The exhaust port (1-1) of the compressor (1) is connected to the port (2-1) of the four-way reversing valve (2), the port (2-1) of the four-way reversing valve (2) is in communication with the port (2-3), the port (2-3) of the four-way reversing valve (2) is connected to the outlet (9-2) of the fourth heat exchanger (9), the inlet (9-1) of the fourth heat exchanger (9) is connected to the inlet of the second expansion valve (11), the outlet of the second expansion valve (11) is connected to the port (10-3) of the flasher (10), the port (10-2) of the flasher (10) is connected to the outlet (8-2) of the third heat exchanger (8), the inlet (8-1) of the third heat exchanger (8) is connected to the inlet of the first expansion valve (7), and the outlet (8-2) of the first expansion valve (7) is connected to the outlet (8-3) of the flasher (10). The outlet of the expansion valve (7) is connected in parallel with the outlet (4-2) of the first heat exchanger (4) and the outlet (6-2) of the second heat exchanger (6) through pipelines. The inlet (6-1) of the second heat exchanger (6) is connected in parallel with the inlet (4-1) of the first heat exchanger (4) through the second solenoid valve (5) and the first solenoid valve (3) and then connected to the port (2-2) of the four-way reversing valve (2). The port (2-2) of the four-way reversing valve (2) is connected to the port (2-4). The port (2-4) of the four-way reversing valve (2) is connected to the inlet of the gas-liquid separator (12). The outlet of the gas-liquid separator (12) is connected to the low-pressure suction port (1-2) of the compressor (1), thereby completing the heat pump cycle process.

[0018] A control method for a heat pump type temperature and humidity control unit, the method realizing temperature and humidity control of supply air or return air through a cooling and dehumidification mode and a heating and humidification operation mode.

[0019] Optionally, in the cooling and dehumidification mode, the return air to be treated is cooled and its relative humidity is increased after heat exchange in the third heat exchanger (8), and then enters the fourth heat exchanger (9) for deep cooling and dehumidification. The condensed water of the fourth heat exchanger (9) flows back to the condensation water tank (13) under the action of gravity. The air after heat and humidity treatment by the third heat exchanger (8) and the fourth heat exchanger (9) is atomized and humidified by the ultrasonic humidifier (14) according to the air supply parameter control, and then the temperature is adjusted by the condensation heat through the first heat exchanger (4), so that the temperature and humidity of the supply air or the temperature and humidity of the return air meet the control target requirements.

[0020] Optionally, the supply air temperature can be adjusted by the first solenoid valve (3) to adjust the heating amount of the first heat exchanger (4), and the humidity of the supply air or return air can be controlled by humidification through an ultrasonic humidifier (14).

[0021] Optionally, in the heating and humidification operation mode, the third heat exchanger (8) acts as a subcooler, the fourth heat exchanger (9) acts as a condenser, and the low-temperature return air (16) is first preheated by the third heat exchanger (8) and then heated by the fourth heat exchanger (9) to achieve primary heating control of the air supply parameters. Then, according to the air supply temperature and humidity targets, the humidification amount of the ultrasonic humidifier (14) is adjusted to control the air supply humidity, and the first solenoid valve (3) is adjusted to control the heat exchange amount of the first heat exchanger (4) to control the air supply temperature, thereby achieving secondary heat and humidity control of the air supply temperature and humidity.

[0022] Optionally, the humidification amount of the ultrasonic humidifier is controlled according to the outlet air temperature and absolute humidity content of the fourth heat exchanger (9), and the cooling heat exchange amount of the first heat exchanger (4) is controlled by the first solenoid valve (3) to achieve precise control and adjustment of the supply air or return air temperature and humidity.

[0023] Beneficial technical effects:

[0024] 1. Decouple the wet air temperature control from the humidity control to achieve high-precision and stable control of the supply or return air temperature and humidity;

[0025] 2. The dual evaporation temperature and intermediate air-supply compression technology are adopted to reduce the energy consumption of the compressor and improve the energy efficiency level of the air heat and humidity treatment process; the intermediate air-supply cooling of the compressor improves the adaptability of the unit to working conditions, especially to harsh working conditions;

[0026] 3. Use condensation heat and subcooling reheat technology to reduce the energy consumption of the traditional air temperature reheating adjustment process and improve the performance of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0028] Figure 1 Schematic diagram of heat pump cycle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0031] Embodiment 1

[0032] like Figure 1 As shown, a heat pump type temperature and humidity control unit and a control method thereof include:

[0033] The heat pump cycle of the present invention includes a compressor 1 with an intermediate air supply port, a four-way reversing valve 2, a gas-liquid separator 12, a flasher 10, a first heat exchanger 4, a second heat exchanger 6, a third heat exchanger 8, a fourth heat exchanger 9, a first solenoid valve 3, a second solenoid valve 5, a first expansion valve 7, a second expansion valve 11 and a refrigerant pipeline.

[0034] The air treatment loop is as follows: the return air is sent out in the direction of air flow, passing through the third heat exchanger 8, the fourth heat exchanger 9, the ultrasonic humidifier 14 and the first heat exchanger 4 in sequence.

[0035] Specific process of heat pump temperature and humidity control system:

[0036] 1. Cooling and dehumidification mode

[0037] The exhaust port 1-1 of the compressor 1 is connected to the 2-1 port of the four-way reversing valve 2 through a high-pressure gaseous refrigerant pipeline, the 2-1 port of the four-way reversing valve 2 is connected to the 2-2 port, the 2-2 port of the four-way reversing valve 2 is connected in parallel to the inlets of the first solenoid valve 3 and the second solenoid valve 5 through the high-pressure refrigerant pipeline, the outlet of the first solenoid valve 3 is connected to the inlet 4-1 of the first heat exchanger 4 through the refrigerant pipeline, the outlet of the second solenoid valve 5 is connected to the inlet 6-1 of the second heat exchanger 6, the second heat exchanger 6 is placed outdoors, the outlet 4-2 of the first heat exchanger 4 and the outlet 6-2 of the second heat exchanger 6 are connected to the inlet of the first expansion valve 7 after being connected in parallel through the high-pressure liquid refrigerant pipeline, and the outlet of the first expansion valve 7 is connected to the inlet 6-1 of the second heat exchanger 6. The inlet 8-1 of the third heat exchanger 8 is connected, the outlet 8-2 of the third heat exchanger 8 is connected to the 10-2 port of the flasher 10, the 10-3 port of the flasher 10 is connected to the inlet of the second expansion valve 11, the 10-1 port of the flasher 10 is connected to the intermediate air supply port 1-3 port of the compressor 1, the outlet of the second expansion valve 11 is connected to the inlet 9-1 of the fourth heat exchanger 9, the outlet 9-2 of the fourth heat exchanger 9 is connected to the 2-3 port of the four-way reversing valve 2, the 2-3 port of the four-way reversing valve is connected to the 2-4 port, the 2-4 port is connected to the inlet of the gas-liquid separator 12, and the outlet of the gas-liquid separator 12 is connected to the low-pressure suction port 1-2 of the compressor 1, thereby completing the circulation process of the refrigerant.

[0038] After the return air 16 to be treated passes through the third heat exchanger 8 for heat exchange, its temperature is reduced and its relative humidity is increased, and then it enters the fourth heat exchanger 9 for deep cooling and dehumidification. The condensed water of the fourth heat exchanger 9 flows back to the condensed water tank 13 under the action of gravity. The air after the heat and humidity treatment by the third heat exchanger 8 and the fourth heat exchanger 9 is atomized and humidified by the ultrasonic humidifier 14 according to the air supply parameter control, and then the air is temperature-controlled by the first heat exchanger 4 using the condensation heat, so that the temperature and humidity of the supply air or the temperature and humidity of the return air meet the control target requirements.

[0039] Preferably, in order to achieve high-precision control of temperature and humidity, the supply air temperature can be adjusted by the first solenoid valve 3 to adjust the heating amount of the first heat exchanger 4 , and the humidity of the supply air 17 can be controlled by humidification through the ultrasonic humidifier 14 .

[0040] Preferably, the cooling and dehumidification operation control process is:

[0041] 1) According to the properties of wet air, the dry bulb temperature Ta and relative humidity φ are fitted into the absolute humidity content d expression: d = f (Ta, φ). Therefore, by setting the supply air or return air temperature Tset and the relative humidity φset, the set supply air or return air absolute humidity content dset can be obtained; at the same time, by detecting the supply air or return air temperature Th and φ, the real-time supply air and return air absolute humidity content d value can be obtained;

[0042] 2) The four-way reversing valve is switched to the cooling operation mode, that is, the 2-1 port is connected to the 2-2 port, the 2-3 port is connected to the 2-4 port, and the high-temperature and high-pressure gas refrigerant compressed by the compressor is distributed to the first heat exchanger 4 and the second heat exchanger 6 through the four-way reversing valve, the first solenoid valve 3, and the second solenoid valve 5 respectively. The high-pressure gas refrigerant is condensed into high-pressure liquid in the first heat exchanger 4 and the second heat exchanger 6. The condensed high-pressure liquid is throttled to the gas-liquid two-phase of the intermediate pressure through the first expansion valve 7 after converging, and enters the third heat exchanger 8 to pre-cool the return air 16, and part of the liquid refrigerant is vaporized, and the gas-liquid two-phase of the intermediate pressure is controlled. The refrigerant flows back to the flash evaporator 10, where gas-liquid separation is carried out. The separated intermediate-pressure saturated steam is fed into the intermediate air supply port 1-3 of the compressor 2. The separated intermediate-pressure saturated liquid is throttled to a low-pressure gas-liquid two-phase state through the second expansion valve 11 and enters the fourth heat exchanger 9. The humid air pre-cooled by the third heat exchanger 8 is frozen and dehumidified, so that the moisture content d9 of the air at the outlet of the fourth heat exchanger 9 is lower than or equal to the set supply air moisture content dset. The low-pressure gaseous refrigerant after absorbing heat returns to the low-pressure air intake port of the compressor 1 through the four-way reversing valve 2 and the gas-liquid separator 12, completing the refrigerant circulation process.

[0043] The humid air after two-stage cooling and dehumidification by the third heat exchanger 8 and the fourth heat exchanger 9 is used to judge or control the humidification amount of the ultrasonic humidifier according to the absolute moisture content d9 measured at the outlet of the fourth heat exchanger 9; the reheating demand of the first heat exchanger 4 is judged according to the temperature of the humid air after humidification and the supply air or return air temperature setting value, and the heating amount of the first heat exchanger 4 is controlled by the first solenoid valve to realize the control of the supply air or return air temperature.

[0044] The above-mentioned double evaporation temperature is used for precooling and freezing dehumidification of the return air and reheating of the first heat exchanger condenser to achieve decoupling and precise control of the supply air or return air temperature and humidity, thereby achieving the purpose of constant temperature and humidity control.

[0045] In this mode, the third heat exchanger 8 cools the return air 16 at a high evaporation temperature, and then dehumidifies it at a low evaporation temperature through the fourth heat exchanger 9 to achieve a primary precise control of the cooling and dehumidification of the supply air parameters. The subsequent ultrasonic humidification and reheating of the first heat exchanger 4 achieve a secondary precise control of the humidity and heating of the supply air parameters.

[0046] 2. Heating and humidification operation mode

[0047] This mode is a heat pump operation mode, the exhaust port 1-1 of the compressor 1 is connected to the port 2-1 of the four-way reversing valve 2, the port 2-1 of the four-way reversing valve 2 is connected to the port 2-3, the port 2-3 of the four-way reversing valve 2 is connected to the port 9-2 of the fourth heat exchanger 9, the port 9-1 of the fourth heat exchanger 9 is connected to the inlet of the second expansion valve 11, the outlet of the second expansion valve 11 is connected to the port 10-3 of the flasher 10, the port 10-2 of the flasher 10 is connected to the port 8-2 of the third heat exchanger 8, the port 8-1 of the third heat exchanger 8 is connected to the inlet of the first expansion valve 7, and the outlet of the first expansion valve 11 is connected to the port 10-3 of the flasher 10. The outlet of the expansion valve 7 is connected in parallel with the 4-2 port of the first heat exchanger 4 and the 6-2 port of the second heat exchanger 6 respectively through pipelines. The 6-1 port of the second heat exchanger 6 is connected in parallel with the 4-1 port of the first heat exchanger 4 through the second solenoid valve 5 and the first solenoid valve 3 and then connected to the 2-2 port of the four-way reversing valve 2. The 2-2 port of the four-way reversing valve 2 is connected to the 2-4 port. The 2-4 port of the four-way reversing valve 2 is connected to the inlet of the gas-liquid separator 12. The outlet of the gas-liquid separator 12 is connected to the low-pressure suction port 1-2 of the compressor 1, thereby completing the heat pump cycle process.

[0048] Preferably, the heating and humidification operation control process is:

[0049] 1) According to the properties of wet air, the dry bulb temperature Ta and relative humidity φ are fitted into the absolute humidity content d expression: d = f (Ta, φ). Therefore, by setting the supply air or return air temperature Tset and the relative humidity φset, the set supply air or return air absolute humidity content dset can be obtained; at the same time, by detecting the supply air or return air temperature Th and φ, the real-time supply air and return air absolute humidity content d value can be obtained;

[0050] 2) The four-way reversing valve is switched to the heating operation mode, that is, the 2-1 port is connected to the 2-3 port, the 2-2 port is connected to the 2-4 port, and the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged to the fourth heat exchanger 9 through the four-way reversing valve 2 to heat the return air. The refrigerant is condensed into a high-pressure liquid in the fourth heat exchanger 9, and then throttled to the gas-liquid two-phase of the intermediate pressure through the second expansion valve and flows back to the flash igniter 10. The saturated steam is separated in the flash igniter and fed into the intermediate gas feed port 1-3 of the compressor 2. The separated high-pressure gas refrigerant is then fed to the intermediate gas feed port 1-3 of the compressor 2. The high-pressure liquid enters the third heat exchanger to preheat the return air 16. The supercooled intermediate-pressure liquid refrigerant is throttled to a low-pressure gas-liquid two-phase state through the first expansion valve 7 for secondary throttling, and then distributed in parallel to the first heat exchanger 4 and the second heat exchanger 6 through the low-pressure refrigerant pipeline. After absorbing heat and gasifying in the first heat exchanger 4 and the second heat exchanger 6, they pass through the first solenoid valve 3 and the second solenoid valve 5 respectively and then converge to the 2-4 port of the four-way reversing valve 2, and then pass through the gas-liquid separator 12 to the low-pressure air supply port 1-2 of the compressor 1 to complete the heating cycle.

[0051] The return air 16 is first preheated by the third heat exchanger 8 using the supercooling heat of the intermediate pressure liquid refrigerant to increase the supercooling degree of the liquid refrigerant at the outlet of the third heat exchanger. The heated air enters the fourth heat exchanger 9 and is secondary heated to the set supply air temperature using the high-temperature and high-pressure refrigerant discharged from the compressor 2. The humidification amount of the ultrasonic humidifier is controlled according to the outlet air temperature and absolute humidity content of the fourth heat exchanger 9, and the cooling heat exchange amount of the first heat exchanger 4 is controlled by the first solenoid valve 3 to achieve precise control and adjustment of the supply or return air temperature and humidity.

[0052] In this mode, the third heat exchanger 8 acts as a subcooler and the fourth heat exchanger 9 acts as a condenser. The low-temperature return air 16 is first preheated by the third heat exchanger 8 and then heated by the fourth heat exchanger 9 to achieve primary heating control of the air supply parameters. Then, according to the air supply temperature and humidity targets, the humidification amount of the ultrasonic humidifier 14 is adjusted to control the air supply humidity, and the first solenoid valve 3 is adjusted to control the heat exchange amount of the first heat exchanger 4 to control the air supply temperature, thereby achieving secondary heat and humidity control of the air supply temperature and humidity.

[0053] According to the characteristics of the wet air freezing and dehumidification process, a double evaporation temperature evaporator is used to freeze and dehumidify the wet air, that is, the return air to be processed is first pre-cooled by the high-temperature evaporator to make the relative humidity of the air close to the dew point temperature, and then passed through the low-temperature evaporator for freezing and dehumidification, thereby improving the dehumidification efficiency of the low-temperature evaporator and increasing the evaporation temperature of the high-temperature evaporator, which is beneficial to improving the energy efficiency level of the compressor.

[0054] A quasi-two-stage compression system with intermediate air supply is adopted. The medium-pressure gas after vaporization in the high-temperature evaporator is supplied to the intermediate air supply port of the compressor through the flash device. The low-pressure steam returns to the low-pressure suction port of the compressor after heat absorption and vaporization in the low-temperature evaporator. After adopting a two-stage evaporation temperature, the low-temperature evaporator mainly bears the dehumidification demand, and the refrigerant mass flow rate of the low-temperature evaporator is reduced. For the compressor, the power consumption of the low-pressure refrigerant compression process can be reduced, and the overall energy efficiency level of the compressor can be improved.

[0055] The reheating process of the supply air adopts part of the condensation heat, that is, the condenser of the first heat exchanger is used to reheat and adjust the temperature of the air after the refrigeration and dehumidification of the third and fourth heat exchangers; the recovered condensed water is used to humidify and adjust the humidity of the air after the refrigeration and dehumidification by an ultrasonic humidification method.

[0056] In the heating mode, the low-temperature return air is first preheated by the third heat exchanger using the supercooling heat, and then heated by the fourth heat exchanger 9 using the condensation heat. The third heat exchanger acts as a supercooler, which can increase the inlet supercooling degree of the first expansion valve, which is beneficial to improving the cycle performance; the air heated by the third and fourth heat exchangers is then cooled and temperature-controlled by the first heat exchanger (acting as an evaporator), and the humidity is regulated by ultrasonic humidification to achieve precise control of the air supply parameters;

[0057] Decoupled control of temperature and humidity: According to the performance of wet air, the measured temperature and relative humidity are converted into the absolute humidity content (d) of wet air. Similarly, the required temperature and relative humidity of supply or return air are converted into the absolute humidity content (d). In humidity control, the dehumidification capacity of the evaporator and the humidification capacity of the ultrasonic humidifier are adjusted according to the required absolute humidity content (d). This adjustment process is not affected by temperature adjustment. The heat exchange capacity of the heat exchanger is controlled according to the supply or return air temperature. The temperature adjustment process is not affected by humidity adjustment. Decoupling of temperature and humidity control is achieved.

[0058] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0059] It should be noted that the serial numbers of the embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0060] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, and any combination of embodiments or schemes are also included in the patent protection scope of the present invention.

Claims

1. A heat pump type temperature and humidity control unit, characterized in that: The invention comprises a compressor with an intermediate air supply port (1), a four-way reversing valve (2), a gas-liquid separator (12), a flasher (10), a first heat exchanger (4), a second heat exchanger (6), a third heat exchanger (8), a fourth heat exchanger (9), a first solenoid valve (3), a second solenoid valve (5), a first expansion valve (7), a second expansion valve (11) and a refrigerant pipeline.

2. The heat pump type temperature and humidity control unit according to claim 1, characterized in that: The air processing loop of the heat pump type temperature and humidity control unit is as follows: the return air is sent out in sequence through the third heat exchanger (8), the fourth heat exchanger (9), the ultrasonic humidifier (14) and the first heat exchanger (4) along the air flow direction.

3. The heat pump type temperature and humidity control unit according to claim 1 or 2, characterized in that: The heat pump type temperature and humidity control unit has the functions of cooling and humidity control and heating and humidity control.

4. The heat pump type temperature and humidity control unit according to claim 3, characterized in that: The cooling and humidity control function is realized as follows: The exhaust port (1-1) of the compressor (1) is connected to the port (2-1) of the four-way reversing valve (2) through a high-pressure gaseous refrigerant pipeline, the port (2-1) of the four-way reversing valve (2) is connected to the port (2-2), the port (2-2) of the four-way reversing valve (2) is connected in parallel to the inlets of the first solenoid valve (3) and the second solenoid valve (5) through the high-pressure refrigerant pipeline, the outlet of the first solenoid valve (3) is connected to the inlet (4-1) of the first heat exchanger (4) through the refrigerant pipeline, the outlet of the second solenoid valve (5) is connected to the inlet (6-1) of the second heat exchanger (6), the second heat exchanger (6) is placed outdoors, the outlet (4-2) of the first heat exchanger (4) and the outlet (6-2) of the second heat exchanger (6) are connected in parallel to the inlet of the first expansion valve (7) through the high-pressure liquid refrigerant pipeline, and the outlet of the first expansion valve (7) is connected to the inlet of the third expansion valve (7). The inlet (8-1) of the heat exchanger (8) is connected, the outlet (8-2) of the third heat exchanger (8) is connected to the (10-2) port of the flasher (10), the (10-3) port of the flasher (10) is connected to the inlet of the second expansion valve (11), the (10-1) port of the flasher (10) is connected to the intermediate air supply port (1-3) port of the compressor (1), the outlet of the second expansion valve (11) is connected to the inlet (9-1) of the fourth heat exchanger (9), the outlet (9-2) of the fourth heat exchanger (9) is connected to the (2-3) port of the four-way reversing valve (2), the (2-3) port of the four-way reversing valve is connected to the (2-4) port, the (2-4) port is connected to the inlet of the gas-liquid separator (12), and the outlet of the gas-liquid separator (12) is connected to the low-pressure air intake port (1-2) of the compressor (1), thereby completing the circulation process of the refrigerant.

5. The heat pump type temperature and humidity control unit according to claim 3, characterized in that: The heating and humidity control function is realized as follows: The exhaust port (1-1) of the compressor (1) is connected to the port (2-1) of the four-way reversing valve (2), the port (2-1) of the four-way reversing valve (2) is in communication with the port (2-3), the port (2-3) of the four-way reversing valve (2) is connected to the outlet (9-2) of the fourth heat exchanger (9), the inlet (9-1) of the fourth heat exchanger (9) is connected to the inlet of the second expansion valve (11), the outlet of the second expansion valve (11) is connected to the port (10-3) of the flasher (10), the port (10-2) of the flasher (10) is connected to the outlet (8-2) of the third heat exchanger (8), the inlet (8-1) of the third heat exchanger (8) is connected to the inlet of the first expansion valve (7), and the outlet (8-2) of the first expansion valve (7) is connected to the outlet (8-3) of the flasher (10). The outlet of the expansion valve (7) is connected in parallel with the outlet (4-2) of the first heat exchanger (4) and the outlet (6-2) of the second heat exchanger (6) through pipelines. The inlet (6-1) of the second heat exchanger (6) is connected in parallel with the inlet (4-1) of the first heat exchanger (4) through the second solenoid valve (5) and the first solenoid valve (3) and then connected to the port (2-2) of the four-way reversing valve (2). The port (2-2) of the four-way reversing valve (2) is connected to the port (2-4). The port (2-4) of the four-way reversing valve (2) is connected to the inlet of the gas-liquid separator (12). The outlet of the gas-liquid separator (12) is connected to the low-pressure suction port (1-2) of the compressor (1), thereby completing the heat pump cycle process.

6. A control method for a heat pump type temperature and humidity control unit, comprising the heat pump type temperature and humidity control unit according to any one of claims 1 to 5, characterized in that: The temperature and humidity of supply air or return air can be controlled through the cooling and dehumidification mode and the heating and humidification operation mode.

7. The control method according to claim 6, characterized in that: In the cooling and dehumidification mode, after the return air to be treated has undergone heat exchange in the third heat exchanger (8), its temperature is reduced and its relative humidity is increased, and it then enters the fourth heat exchanger (9) for deep cooling and dehumidification. The condensed water in the fourth heat exchanger (9) flows back to the condensed water tank (13) under the action of gravity. After the air has been heat-humidified by the third heat exchanger (8) and the fourth heat exchanger (9), it is atomized and humidified by the ultrasonic humidifier (14) according to the air supply parameter control, and then it is temperature-controlled by the first heat exchanger (4) using the condensation heat, so that the temperature and humidity of the supply air or the temperature and humidity of the return air meet the control target requirements.

8. The control method according to claim 7, characterized in that: The supply air temperature can be adjusted by the first solenoid valve (3) to adjust the heating amount of the first heat exchanger (4), and the humidity of the supply air or return air can be controlled by humidification through the ultrasonic humidifier (14).

9. The control method according to claim 6, characterized in that: In the heating and humidifying operation mode, the third heat exchanger (8) acts as a subcooler and the fourth heat exchanger (9) acts as a condenser. The low-temperature return air (16) is first preheated by the third heat exchanger (8) and then heated by the fourth heat exchanger (9) to achieve primary heating control of the air supply parameters. Then, according to the air supply temperature and humidity targets, the humidification amount of the ultrasonic humidifier (14) is adjusted to control the air supply humidity, and the first solenoid valve (3) is adjusted to control the heat exchange amount of the first heat exchanger (4) to control the air supply temperature, thereby achieving secondary heat and humidity control of the air supply temperature and humidity.

10. The control method according to claim 9, characterized in that: The humidification amount of the ultrasonic humidifier is controlled according to the outlet air temperature and absolute humidity of the fourth heat exchanger (9), and the cooling heat exchange amount of the first heat exchanger (4) is controlled through the first solenoid valve (3), so as to achieve accurate control and adjustment of the supply air or return air temperature and humidity.

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