Control method of solution dehumidification system coupled with heat pump system

Abstract

The invention relates to the technical field of heat pumps, in particular to a control method of a solution dehumidification system coupled with a heat pump system, and aims to solve the problems of complex and huge system, high energy consumption and the like caused by independent configuration of a heating device during regeneration of a solution dehumidizer in the prior art. In order to achieve the purpose, the heat pump system and the solution dehumidification system share an evaporator and a condenser, and the control method comprises the steps that the heat pump system and the solution dehumidification system are controlled to operate; the humidity of the dehumidified air is obtained; whether the humidity of the dehumidified air meets the requirement or not is judged; and based on the judgment result, the operation parameters of the heat pump system are selectively adjusted, and the operation parameters at least comprise the throttling temperature. The solution dehumidification system and the heat pump system share the evaporator and the condenser, and the operation parameters of the heat pump system are adjusted based on the judgment result whether the humidity of the dehumidified air meets the requirement or not, so that the operation state of the heat pump system can be automatically adjusted, and the system energy efficiency is improved while the air humidity requirement is met.

Description

Technical Field

[0001] The invention relates to the technical field of heat pumps, and in particular provides a control method for a solution dehumidification system coupled to a heat pump system. Background Art

[0002] Conventional condensation dehumidification usually cools the air to the target dew point temperature to achieve the purpose of dehumidification. This method removes a large amount of sensible heat during the dehumidification process, resulting in energy waste. To overcome this problem, there is also a dehumidification method that directly absorbs moisture in the air through a dehumidifier. Dehumidifiers include solid dehumidifiers and solution dehumidifiers. Compared with solid dehumidifiers, solution dehumidifiers (also known as liquid dehumidifiers) are fluid, easier to combine with heat sources and cold sources, and have higher energy efficiency.

[0003] The solute in the solution dehumidifier is hygroscopic, so the vapor pressure on its surface is much lower than that of the air at room temperature. Driven by the vapor pressure difference, water vapor diffuses from the air into the solution dehumidifier. This is the principle of dehumidification by the solution dehumidifier. The lower the temperature and the higher the concentration of the solution dehumidifier, the lower the surface vapor pressure and the stronger the dehumidification capacity. During the dehumidification process, the solution dehumidifier continuously absorbs water vapor from the air, the concentration of the solute in it decreases, and the dehumidification capacity will be weakened. Therefore, a regeneration device is usually set up to heat the dehumidified dilute solution through the regeneration device to greatly increase the vapor pressure on its surface. After it is higher than the air, the water in the solution dehumidifier is discharged into the air in the form of steam, and the concentration of the solute in it increases, the dehumidification capacity is restored, and the regeneration of the solution dehumidifier is realized. In this case, it is necessary to configure an additional heating device to provide a heat source for the regeneration device to heat the dilute solution, which makes the system complex and large, and has high energy consumption.

[0004] Accordingly, the art needs a new technical solution to solve the above problems. Summary of the invention

[0005] The present invention aims to solve the above technical problems, that is, to solve the problems in the prior art of configuring a heating device separately when regenerating a solution dehumidifier, which results in a complex and bulky system and high energy consumption.

[0006] In a first aspect, the present invention provides a control method for a solution dehumidification system coupled to a heat pump system, characterized in that the heat pump system comprises an evaporator, a compressor, a condenser and a throttling device that are connected to each other, the solution dehumidification system comprises a dehumidification device, a circulation pump, the evaporator, a regeneration device, and the condenser that are connected to each other, the dehumidification device is configured to remove water vapor in the air through a solution dehumidifier to obtain dehumidified air,

[0007] The control method comprises: controlling the operation of the heat pump system and the solution dehumidification system;

[0008] obtaining the humidity of the dehumidified air;

[0009] Determining whether the humidity of the dehumidified air meets the requirements;

[0010] Based on the judgment result, the operating parameters of the heat pump system are selectively adjusted, wherein the operating parameters at least include the throttling temperature.

[0011] In the preferred technical solution of the above control method, the step of "selectively adjusting the operating parameters of the heat pump system based on the first judgment result" specifically includes:

[0012] If the humidity of the dehumidified air is too high, the operating parameters in the heat pump system are adjusted.

[0013] In the preferred technical solution of the above control method, the operating parameters include throttling temperature, and the step of "adjusting the operating parameters in the heat pump system" further includes:

[0014] Adjust the throttling temperature.

[0015] In the preferred technical solution of the above control method, the operating parameters include throttling temperature and evaporation temperature, and the control method further includes:

[0016] The evaporation temperature is adjusted, and the throttling temperature is adjusted simultaneously with or after each adjustment of the evaporation temperature.

[0017] In the preferred technical solution of the above control method, the refrigerant of the heat pump system is a transcritical refrigerant, the operating parameters include exhaust pressure, throttling temperature and evaporation temperature, and the control method further includes:

[0018] The exhaust pressure is adjusted, and the throttling temperature and the evaporation temperature are adjusted simultaneously with or after each adjustment of the exhaust pressure.

[0019] In a preferred technical solution of the above control method, the refrigerant is CO2.

[0020] In the preferred technical solution of the above control method, the control method further includes:

[0021] After each adjustment of the operating parameters, determining whether the humidity of the dehumidified air meets the requirements;

[0022] When or after the humidity of the dehumidified air meets the requirement, calculating the COP value of the entire system under the current operating parameter conditions;

[0023] The optimal COP value corresponding to the current operating parameter conditions is determined based on the change trend of the COP value.

[0024] In the preferred technical solution of the above control method, the operating parameters include throttling temperature, evaporation temperature and exhaust pressure, and the control method further includes:

[0025] After determining the optimal COP value, compare the optimal COP values ​​corresponding to various exhaust pressures;

[0026] The exhaust pressure and evaporation temperature corresponding to the maximum COP value are determined as the optimal exhaust pressure and optimal evaporation temperature.

[0027] In a preferred technical solution of the above control method, the COP value is determined based on the latent heat change of the air entering and exiting the dehumidification device, and the energy consumption of the power equipment of the heat pump system and the solution dehumidification system.

[0028] In a preferred technical solution of the above control method, the heat pump system further includes an auxiliary condenser, and the auxiliary condenser is arranged between the condenser and the throttling device.

[0029] In the technical solution of the present invention, the heat pump system includes an evaporator, a compressor, a condenser and a throttling device that are interconnected. Under the action of the compressor, the refrigerant circulates between various devices through a connecting pipe, releases heat at the condenser and absorbs heat at the evaporator. The solution dehumidification system includes a dehumidification device, a circulating pump, an evaporator, a regeneration device and a condenser that are interconnected. Under the action of the circulating pump, the solution dehumidifier circulates between various devices through a connecting pipe. The solution dehumidifier contacts the air flowing through the dehumidification device at the dehumidification device and adsorbs water vapor in the air, removes water vapor in the air, reduces air humidity, and obtains dehumidified air. The solution dehumidifier exchanges heat with the refrigerant at the evaporator to reduce the temperature. After the solution dehumidifier reduces the temperature, its surface vapor pressure will decrease, and the dehumidification capacity will be enhanced. The solution dehumidifier after cooling can better dehumidify the air flowing through it at the dehumidification device. The water content of the solution dehumidifier that absorbs water from the air increases, the concentration decreases, and the dehumidification capacity weakens. The solution dehumidifier exchanges heat with the refrigerant at the condenser to increase the temperature, and its surface vapor pressure increases. After it is higher than the air, the water in the solution dehumidifier is discharged into the air in the form of steam, the concentration of the solution dehumidifier is increased, and the dehumidification capacity is restored, thereby realizing the regeneration of the solution dehumidifier. In other words, the solution dehumidification system and the heat pump system share the evaporator and condenser, and by sharing the evaporator and condenser, the temperature of the solution dehumidifier can be reduced by the evaporator before dehumidifying the air to increase the dehumidification capacity of the solution dehumidifier, and the temperature of the solution dehumidifier can be increased by the condenser after dehumidifying the air to restore the dehumidification capacity of the solution dehumidifier. Through such a setting, the solution dehumidification system is coupled with the heat pump system, and the cold source and heat source required by the solution dehumidification system are provided by a relatively compact heat pump system, which simplifies the system configuration, and comprehensively utilizes the heat required and released by the two systems, and can operate stably with only a small amount of energy consumption, greatly reducing energy consumption.

[0030] The control method of the present invention includes: controlling the operation of the heat pump system and the solution dehumidification system, obtaining the humidity of the dehumidified air, judging whether the humidity of the dehumidified air meets the requirements, and then selectively adjusting the operation parameters of the heat pump system based on the judgment result. That is, after the operation of the heat pump system and the solution dehumidification system, the present invention adjusts the operation parameters of the heat pump system based on the humidity of the dehumidified air after the dehumidification treatment by the dehumidification device, so that the cooling capacity provided by the evaporator of the heat pump system and the heating capacity provided by the condenser can be automatically adjusted according to actual needs, so that they match the demand for cooling capacity at the dehumidification device in the solution dehumidification system and the demand for heating at the regeneration device, and meet the humidity demand of the dehumidified air. That is to say, based on the solution of the present invention, there is no need for manual adjustment, and there is no need to set up additional auxiliary equipment such as heat exchangers, so that the heat demand of the two systems can reach a dynamic balance, meet the air humidity requirements, and improve the system energy efficiency.

[0031] Furthermore, the refrigerant of the heat pump system is a transcritical refrigerant, that is, the heat pump system of the present invention operates a transcritical refrigeration cycle under the action of the compressor. Under the same operating conditions, the pressure ratio of the transcritical heat pump system compressor is much smaller than the pressure ratio of the ordinary subcritical heat pump system compressor. In this way, the energy consumption of the compressor can be greatly reduced, thereby improving the energy efficiency of the entire system.

[0032] Furthermore, the heat pump system also includes an auxiliary condenser, which is arranged between the condenser and the throttling device. The temperature of the refrigerant can be further reduced through the auxiliary condenser so that it can provide more cooling capacity for the solution dehumidifier at the evaporator, so that the solution dehumidifier can be reduced to a lower temperature and have better dehumidification capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0034] Figure 1 is a schematic structural diagram of a solution dehumidification system coupled to a heat pump system according to an embodiment of the present invention;

[0035] Figure 2 It is a flow chart of adjusting the operating parameters of the heat pump system based on the judgment result of whether the humidity of the dehumidified air meets the requirement according to an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of the temperature entropy of CO2 in a heat pump system when CO2 is used as a refrigerant and a schematic diagram of the temperature change of a solution dehumidifier in a solution dehumidification system in an embodiment of the present invention.

[0037] Reference numerals:

[0038] 1. Compressor; 2. Condenser; 3. Auxiliary condenser; 4. Throttling device; 5. Evaporator; 6. Dehumidification device; 7. First circulation pump; 8. Regeneration device; 9. Second circulation pump. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0040] It should be noted that, in the description of the present application, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0041] At present, since the dehumidification capacity of the liquid dehumidifier is weakened after absorbing water vapor in the air, it is necessary to configure a heating device to provide a heat source in addition to setting a regeneration device for it, resulting in a complex and large system with high energy consumption. To this end, the present invention combines the liquid dehumidification system with the heat pump system and adjusts the operating parameters of the heat pump system based on the humidity of the dehumidified air, so that a relatively compact system can meet the humidity requirements of the dehumidified air, and the two systems can be in an optimal cold and heat balance working state, which effectively improves the system energy efficiency and reduces energy consumption.

[0042] like Figure 1As shown, the heat pump system of the present invention includes an evaporator 5, a compressor 1, a condenser 2 and a throttling device 4 which are interconnected. The throttling device 4 can be a throttling element such as an expansion valve or a capillary tube, and each device is connected to each other through a connecting pipe. The refrigerant coming out of the compressor 1 releases heat at the condenser 2, and after throttling and reducing pressure by the throttling device 4, it absorbs heat at the evaporator 5 and then returns to the compressor 1, and circulates in this way, so that heating capacity can be provided at the condenser 2 and cooling capacity can be provided at the evaporator 5. The solution dehumidification system includes a dehumidification device 6, a first circulating pump 7, an evaporator 5, a regeneration device 8, a second circulating pump 9 and a condenser 2 which are interconnected, and each device is connected to each other through a connecting pipe. The solution dehumidifier contacts the air flowing through the dehumidification device 6 at the dehumidification device 6, and adsorbs water vapor in the air, removes water vapor in the air, reduces air humidity, and obtains dehumidified air. Among them, the solution dehumidifier can be but is not limited to a halogen salt solution, an ionic liquid, etc. During the dehumidification process, the solution dehumidifier absorbs water in the air, causing its concentration to decrease and the dehumidification capacity to weaken. The dilute solution dehumidifier flows to the condenser 2 under the action of the first circulation pump 7, exchanges heat with the refrigerant at the condenser 2 and is heated. The surface vapor pressure of the heated dilute solution dehumidifier increases and is higher than that of the air. The water in it is discharged in the form of steam at the regeneration device 8, and the concentration of the solution dehumidifier is increased, the dehumidification capacity is restored, and the regeneration of the solution dehumidifier is achieved. In other words, the concentration of the solution dehumidifier coming out of the regeneration device 8 has been restored to the initial relatively concentrated level. The concentrated solution dehumidifier flows to the evaporator 5 under the action of the second circulation pump 9, exchanges heat with the refrigerant at the evaporator 5 and is cooled. The surface vapor pressure of the cooled concentrated solution dehumidifier will decrease, and the dehumidification capacity will be enhanced. When the air flowing through it is dehumidified at the dehumidification device 6, it can better absorb water vapor in the air and obtain a better dehumidification effect.

[0043] It should be noted that the solution dehumidification system may also include only one circulation pump. Obviously, the solution dehumidification system may also be provided with three or four or more circulation pumps. The circulation pump may be, but is not limited to, a centrifugal pump, an axial flow pump, a vane pump, a screw pump, a positive displacement pump or other types of pumps.

[0044] It should be noted that the dehumidification device 6 and the regeneration device 8 can be configured as falling film type, packing type, bubbling type or other possible types of heat and mass exchange equipment.

[0045] Continue to refer to Figure 1The heat pump system also includes an auxiliary condenser 3, which is arranged between the condenser 2 and the throttling device 4. The refrigerant coming out of the condenser 2 is further cooled by the auxiliary condenser 3 and then flows to the evaporator 5, thereby providing the evaporator 5 with a refrigerant at a lower temperature. In this way, the evaporator 5 can provide more cooling capacity, and the concentrated solution dehumidifier can be cooled to a lower temperature after heat exchange with the refrigerant at the evaporator 5, further improving the dehumidification capacity of the solution dehumidifier. Less solution dehumidifier is required to reduce the humidity of the same air to a certain level, thereby reducing the system energy consumption and improving the system energy efficiency.

[0046] It should be noted that the auxiliary condenser 3 may be, but is not limited to, an air-cooled heat exchanger, a spray heat exchanger or other possible types of heat exchangers. Obviously, the heat pump system may not be provided with the auxiliary condenser 3.

[0047] In one possible implementation, the refrigerant of the heat pump system is a transcritical refrigerant, which can operate under a large temperature difference. That is to say, in the heat pump system of the present invention, a transcritical refrigeration cycle is operated under the action of a compressor. Under the same operating conditions, the pressure ratio of the transcritical heat pump system is much smaller than that of an ordinary subcritical heat pump system. In this way, the energy consumption of the compressor whose refrigerant is a transcritical refrigerant can be greatly reduced, thereby effectively improving the energy efficiency of the entire system. It should be noted that the transcritical refrigerant can be CO2, difluoromethane, ammonia or other possible substances. Obviously, the refrigerant of the heat pump system can also be an ordinary refrigerant, such as Freon.

[0048] In the present invention, the heat pump system is further configured with a first temperature sensor and a second temperature sensor. The first temperature sensor is arranged at the inlet of the throttling device, and is used to detect the temperature of the refrigerant before the pressure is reduced by the throttling device, which is recorded as the throttling temperature. The second temperature sensor is arranged at the inlet of the evaporator, and is used to detect the temperature of the refrigerant entering the evaporator, which is recorded as the evaporation temperature. Obviously, the first temperature sensor can also be arranged at a position close to the inlet of the throttling device, and the second temperature sensor can also be arranged at a position close to the inlet of the evaporator. Those skilled in the art can flexibly select according to the specific application scenario, as long as the throttling temperature and the evaporation temperature can be accurately detected.

[0049] It should be noted that the first temperature sensor and the second temperature sensor may be, but are not limited to, a thermocouple, a thermistor, a resistance temperature detector, an IC temperature sensor, and the like.

[0050] In the present invention, the heat pump system is further configured with a pressure sensor, which is arranged at the exhaust port of the compressor and is used to detect the pressure of the refrigerant at the exhaust port of the compressor, which is recorded as the exhaust pressure. Obviously, the pressure sensor can also be arranged at a position close to the exhaust port of the compressor, and those skilled in the art can flexibly select it according to the specific application scenario, as long as the exhaust pressure of the compressor can be accurately detected.

[0051] It should be noted that the pressure sensor may be, but is not limited to, a piezoresistive pressure sensor, a piezoelectric pressure sensor, a capacitive pressure sensor, a ceramic pressure sensor or other types of pressure sensors. Of course, the heat pump system may also be equipped with a liquid injection pressure gauge, an elastic pressure gauge or other types of pressure detection devices to detect the exhaust pressure of the compressor.

[0052] In the present invention, the solution dehumidification system is further provided with a humidity sensor, which is arranged at the air outlet of the dehumidification device and is used to detect the humidity of the dehumidified air that has been dehumidified by the solution dehumidifier. Obviously, the humidity sensor can also be arranged at any position on the pipe connected to the air outlet of the dehumidification device, as long as the humidity of the dehumidified air after dehumidification can be accurately detected.

[0053] It should be noted that the humidity sensor may be, but is not limited to, a lithium chloride humidity sensor, a carbon humidity sensor, an alumina humidity meter, a ceramic humidity sensor, and the like.

[0054] In the present invention, the heat pump system is further configured with a control module, which is respectively connected to the first temperature sensor, the second temperature sensor, the pressure sensor and the humidity sensor, and can adjust the operating parameters of the heat pump system based on the judgment result of whether the humidity of the dehumidified air meets the requirements, and can determine the optimal exhaust pressure and the optimal evaporation temperature based on the change trend of the COP value of the heat pump system at the same time or after the humidity of the dehumidified air meets the requirements. Of course, the control module can also be configured in the solution dehumidification system.

[0055] It should be noted that such a control module can physically be a control chip of the heat pump system or the liquid dehumidification system itself, or can be a functional module or functional unit of a general controller.

[0056] Combine the following Figure 2 To illustrate possible implementations of the control method of the present invention.

[0057] In a possible implementation, Figure 2 As shown, the control method of the present invention includes:

[0058] S10: Control the operation of the heat pump system and the solution dehumidification system;

[0059] S11: Obtaining the humidity of the dehumidified air;

[0060] S12: Determine whether the humidity of the dehumidified air meets the requirements;

[0061] S13: Selectively adjusting the operating parameters of the heat pump system based on the judgment result.

[0062] In S10, the operation of the heat pump system and the solution dehumidification system is first controlled, wherein the heat pump system can be controlled to operate under initial conditions, the initial conditions including initial exhaust pressure, initial evaporation temperature and initial throttling temperature, and the first circulation pump and the second circulation pump of the solution dehumidification system are controlled to operate at a preset power.

[0063] In S11, after the heat pump system and the solution dehumidification system are running, the air flowing through them is dehumidified by the dehumidification device to obtain dehumidified air, and the humidity of the dehumidified air is obtained by the humidity sensor.

[0064] In S12, based on the humidity obtained in S11, it is determined whether it meets the requirements. Generally speaking, there is a humidity requirement for the dehumidified air after dehumidification by the dehumidifier, for example, lower than a certain humidity or not higher than a certain humidity, for example, lower than 45%. In this case, if the humidity obtained in S11 is higher than 45%, for example, 55%, it means that the humidity of the dehumidified air does not meet the requirements. If the humidity obtained in S11 is lower than 45%, for example, 43%, it means that the humidity of the dehumidified air meets the requirements.

[0065] In S13, the operating parameters of the heat pump system are selectively adjusted based on the judgment result in S12, and the operating parameters at least include the throttling temperature.

[0066] Through the above setting method, the operating parameters of the heat pump system are selectively adjusted based on the judgment result of whether the humidity of the dehumidified air meets the requirements, so that the cooling capacity provided by the evaporator of the heat pump system and the heating capacity provided by the condenser can be automatically adjusted according to actual needs, so that they match the demand for cooling capacity at the dehumidification device and the demand for heating capacity at the regeneration device. Without manual adjustment and the need to set up additional auxiliary equipment such as heat exchangers, the heat demands of the two systems can be dynamically balanced, and while meeting the air humidity requirements, the two systems are always in an optimal cold and heat balance working state, effectively improving the system energy efficiency.

[0067] In a possible implementation, when it is determined in S12 that the humidity of the dehumidified air meets the requirements, it indicates that the heat pump system can provide sufficient heating and cooling capacity for the solution dehumidification system when operating under the current conditions, and the current operating conditions can be maintained without adjustment.

[0068] In another possible implementation, it is determined in S12 that the humidity of the dehumidified air does not meet the requirements, indicating that the heat pump system operating under the current conditions cannot meet the heating and cooling capacity requirements of the solution dehumidification system. At this time, it is necessary to adjust the operating parameters of the heat pump system. The cooling and heating capacity provided by the heat pump system are adjusted by adjusting the operating parameters to match the heating and cooling capacity requirements of the solution dehumidification system, so that the humidity of the dehumidified air meets the actual humidity requirements. At the same time, the heat pump system can also achieve a cold and hot balance, ensure stable operation of the system, and improve system energy efficiency.

[0069] In a possible implementation, the operating parameters include a throttling temperature, and the throttling temperature is adjusted when adjusting the operating parameters of the heat pump system. Taking the auxiliary condenser as an air-cooled heat exchanger as an example, on the basis of the initial air supply volume of the air-cooled heat exchanger, the air supply volume is increased, the temperature of the refrigerant is further reduced, and the throttling temperature is lowered from the initial throttling temperature, so that the temperature of the refrigerant entering the evaporator is reduced, the cooling capacity provided by it is increased, and the temperature of the concentrated solution dehumidifier exchanging heat with it is further reduced. The solution dehumidifier with a lower temperature can better absorb moisture in the air, reduce the humidity of the dehumidified air, and meet the humidity requirements of the dehumidified air.

[0070] In a possible implementation, the operating parameters include evaporation temperature and throttling temperature. When adjusting the operating parameters of the heat pump system, the throttling temperature can be adjusted first. If the throttling temperature is lowered to the lowest temperature and the humidity requirement of the dehumidified air cannot be met, for example, when the throttling temperature is lowered to 25°C, the humidity of the dehumidified air is still high. At this time, the evaporation temperature is adjusted, for example, by adjusting the opening of the throttling device to adjust the evaporation temperature. The throttling temperature is adjusted after each adjustment of the evaporation temperature, in order to find a throttling temperature that can meet the humidity requirement of the dehumidified air at each evaporation temperature. In this way, the humidity requirement of the dehumidified air can be met, and the excessive energy consumption of the entire system due to the low evaporation temperature can be avoided.

[0071] It should be noted that when adjusting the operating parameters of the heat pump system, only the evaporation temperature may be adjusted, that is, the operating parameters may only include the evaporation temperature.

[0072] In a possible implementation, when the refrigerant of the heat pump system is a transcritical refrigerant, for example, when the refrigerant is CO2, due to the particularity of the transcritical refrigerant, it can work in a larger temperature range. In this case, the operating parameters of the heat pump system may include the throttling temperature, the evaporation temperature and the exhaust pressure. When adjusting the operating parameters, the exhaust pressure may be adjusted, for example, by controlling the refrigerant circulation amount in the heat pump system through a throttling device, and adjusting the throttling temperature and the evaporation temperature after each adjustment of the exhaust pressure, in order to find the evaporation temperature and the throttling temperature that can meet the humidity requirements of the dehumidified air at each exhaust pressure. It should be noted that the method of adjusting the throttling temperature and the evaporation temperature here is similar to the adjustment method when the above-mentioned operating parameters only include the throttling temperature and the evaporation temperature, that is, the evaporation temperature is adjusted first, and then the throttling temperature is adjusted after each adjustment of the evaporation temperature so that the humidity of the dehumidified air meets the requirements.

[0073] In order to improve the system energy efficiency while meeting the humidity requirements, after each adjustment of the operating parameters of the heat pump system, it is determined whether the humidity of the dehumidified air meets the requirements. After the humidity of the dehumidified air meets the requirements, the COP value of the entire system under the current operating parameter conditions is calculated, and the energy consumption of the system is evaluated by the COP value. In order to optimize the energy efficiency of the entire system, after the humidity of the dehumidified air meets the requirements, the operating parameters are still adjusted according to the previous adjustment method. For example, on the basis of the initial throttling temperature and the initial evaporation temperature, the humidity of the dehumidified air meets the requirements by lowering the evaporation temperature and the throttling temperature. Then, the adjustment is continued by lowering the evaporation temperature and the throttling temperature. The throttling temperature that can meet the dehumidification requirements at each evaporation temperature is found, and the COP value of the system under this condition is calculated. Then, based on the change trend of each COP value, the corresponding optimal COP value under the current operating parameter conditions is determined. During the adjustment process, the COP value usually increases first and then decreases. The larger the COP value, the better the energy efficiency of the system. Therefore, the maximum COP value is usually the optimal COP value.

[0074] For example, taking the exhaust pressure of 9Mpa and the throttling temperature as low as 25℃ as an example, under this exhaust pressure, the evaporation temperature is reduced from 10℃ by 1℃ each time. Each time the evaporation temperature is reduced, the throttling temperature is reduced from the highest temperature (for example, 40℃), and the humidity of the dehumidified air is detected in real time to find the throttling temperature that can meet the dehumidification demand. When the evaporation temperature is reduced to 7℃ and the throttling temperature is reduced to the lowest temperature of 25℃, the humidity of the dehumidified air meets the requirements, and the COP value of the whole system is 2. Continue to reduce the evaporation temperature. When the evaporation temperature is 4℃ and the throttling temperature is 28.2℃, the humidity of the dehumidified air meets the requirements. At this time, the COP value of the whole system is 2.8. When the evaporation temperature is 3℃ and the throttling temperature is 29.7℃, the humidity of the dehumidified air meets the requirements. At this time, the COP value of the whole system is 2.7. When the evaporation temperature is 2℃ and the throttling temperature is 30.2℃, the humidity of the dehumidified air meets the requirements. At this time, the COP value of the whole system is 2.6. It can be seen that when the evaporation temperature is 4°C and the throttling temperature is 28.2°C, the COP value of the entire system is the highest, which is the optimal COP value. When operating under this condition, the energy efficiency of the entire system is the highest.

[0075] It should be noted that the lowest throttling temperature is the lowest temperature that the throttling temperature can reach in the current system, which is affected by the ambient temperature and the auxiliary condenser. For example, if the ambient temperature is 22°C and the heat exchange temperature difference of the auxiliary condenser is 3°C, then the lowest throttling temperature is 25°C.

[0076] Of course, the COP value of the entire system can also be calculated while the humidity of the dehumidified air meets the requirements.

[0077] In a possible implementation, when the operating parameters also include exhaust pressure, that is, when the operating parameters include exhaust pressure, throttling temperature and evaporating temperature, then, at each exhaust pressure, an optimal COP value can be obtained. After determining the optimal COP value corresponding to each exhaust pressure, the optimal COP values ​​at each exhaust pressure are compared, and the maximum COP value is determined as the final preferred COP value. The exhaust pressure and evaporating temperature corresponding to it are determined as the optimal exhaust pressure and the optimal evaporating temperature. The heat pump system is controlled to operate at the optimal exhaust pressure, the optimal evaporating temperature and the throttling temperature corresponding to the preferred COP value, which can not only meet the humidity demand of the dehumidified air, but also put the entire system in a state of dynamic balance between cold and heat, thereby obtaining higher energy efficiency and excellent overall performance.

[0078] For example, when the exhaust pressure is 9Mpa, the optimal COP value is 2.8, and its corresponding evaporation temperature is 4°C and the throttling temperature is 28.2°C. When the exhaust pressure is 10Mpa, the optimal COP value is 2.9, and its corresponding evaporation temperature is 5°C and the throttling temperature is 27.5°C. When the exhaust pressure is 11Mpa, the optimal COP value is 2.6, and its corresponding evaporation temperature is 6°C and the throttling temperature is 29°C. Then, the optimal COP value under each exhaust pressure is 2.9, and its corresponding optimal exhaust pressure is 10Mpa, the optimal evaporation temperature is 5°C, and the humidity requirement of the dehumidified air can be met when the throttling temperature is 27.5°C.

[0079] In a possible implementation, the COP value is determined based on the latent heat change of the air entering and exiting the dehumidification device, and the energy consumption of the power equipment of the heat pump system and the solution dehumidification system. Taking the power equipment of the heat pump system as a compressor and the power equipment of the solution dehumidification system as the first circulation pump and the second circulation pump as an example, COP = latent heat change of the air entering and exiting the dehumidification device / (compressor energy consumption + first circulation pump energy consumption + second circulation pump energy consumption), wherein the latent heat change of the air entering and exiting the dehumidification device can be determined by the temperature of the air entering and exiting the dehumidification device, and the energy consumption of the compressor, the first circulation pump and the second circulation pump can be determined by the power consumption of each device. It should be noted that the determination of the latent heat of the air and the energy consumption of the power equipment belongs to relatively conventional technical means in this field and will not be repeated here.

[0080] It should be noted that although the above is based on the COP value of the entire system to optimize the system operating parameters, it is obviously also possible to optimize the system operating parameters based on the power consumption of the entire system. Power consumption refers to the electrical power required by the entire system. When power consumption is used as a benchmark, the lower the power consumption, the better the performance of the entire system.

[0081] Based on this, the present invention adjusts the operating parameters of the heat pump system, determines whether the humidity of the dehumidified air meets the requirements after each adjustment, and calculates the COP value of the entire system when it meets the requirements, determines the optimal COP value, and controls the heat pump system to operate with the operating parameters corresponding to the optimal COP value, which can not only meet the humidity requirements of the dehumidified air, but also enable the system to have higher energy efficiency. When the operating parameters also include exhaust pressure, the optimal COP values ​​under various exhaust pressures are compared, the maximum COP value is determined as the preferred COP value, and the heat pump system is controlled to operate with the operating parameters corresponding to the preferred COP value, which can meet the humidity requirements while obtaining higher energy efficiency.

[0082] The transcritical refrigerant can be CO2 and combined Figure 1 and Figure 3 The following describes in detail the possible implementation methods of heat and cold balance during the operation of the heat pump system and the liquid dehumidification system of the present invention. Figure 3 In the figure, the solid lines connecting points a, b, c, d, and e at the top are the temperature entropy diagram of CO2, the solid parabola at the bottom is the saturation line of CO2, and the dotted lines connecting points H and G, and points I and J are the temperature change curves of the solution. Figure 3 As shown, when the heat pump system is running, under the action of compressor 1, the entropy of the refrigerant changes from point a to point b, the temperature increases, and the saturated state becomes a high-temperature and high-pressure state. Then, after continuous heat release at condenser 2 and auxiliary condenser 3, the entropy of the refrigerant changes from point b to point c and then to point d. Then, after the throttling device 4 reduces the pressure, the entropy of the refrigerant changes from point d to point e, and becomes a low-temperature and low-pressure state. Then, after absorbing heat at evaporator 5, it returns to compressor 1 to form a cycle. In the solution dehumidification system, the temperature of the concentrated solution dehumidifier changes from point G to point H at evaporator 5, the temperature is reduced, and the dehumidification performance is improved. The temperature of the dilute solution dehumidifier changes from point I to point J at condenser 2, and the temperature is increased for regeneration.

[0083] It should be noted that the specific values ​​of the above-mentioned exhaust pressure, throttling temperature, evaporating temperature and COP value are merely exemplary and not restrictive. Those skilled in the art can flexibly select the specific values ​​of exhaust pressure, throttling temperature, evaporating temperature and COP value according to the specific parameters and specific performance of each equipment in the heat pump system and the liquid dehumidification system, as long as the system energy efficiency can be improved while meeting the humidity requirements of the dehumidified air.

[0084] In summary, in the preferred technical solution of the present invention, by coupling the solution dehumidification system with the heat pump system, the solution dehumidification system and the heat pump system share an evaporator and a condenser, and the operating parameters of the heat pump system are adjusted based on the judgment result of whether the humidity of the dehumidified air meets the requirements, so that the cooling capacity provided by the evaporator of the heat pump system and the heating capacity provided by the condenser can be automatically adjusted according to actual needs, so that they match the demand for cooling capacity at the dehumidification device and the demand for heating at the regeneration device, while meeting the air humidity requirements, improving the system energy efficiency. By setting the refrigerant of the heat pump system to a transcritical refrigerant, the exhaust pressure of the compressor can be adjusted while adjusting the throttling temperature and the evaporation temperature, increasing the adjustable space of the entire system, and the pressure ratio of the compressor of the transcritical heat pump system is much smaller than the pressure ratio of the compressor of the ordinary subcritical heat pump system, so that the energy efficiency of the entire system can be better improved.

[0085] It should be noted that the solution dehumidification system coupled with the heat pump system of the present invention can be used for a dehumidifier, a dehumidifier, an air conditioner or other possible equipment or occasions.

[0086] Although the various steps in the above embodiment are described in the above-mentioned chronological order, those skilled in the art can understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple changes are within the scope of protection of this application.

[0087] In addition, the above-mentioned replaceable embodiments, and the replaceable embodiments and the preferred embodiments can also be cross-coordinated and used, so as to combine new embodiments to be suitable for more specific application scenarios. It will be understood by those skilled in the art that although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments means being within the scope of the present invention and forming different embodiments. For example, in the claims of the present invention, any one of the embodiments claimed for protection can be used in any combination.

[0088] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A control method for a solution dehumidification system coupled with a heat pump system, characterized in that: The heat pump system comprises an evaporator, a compressor, a condenser and a throttling device which are interconnected, and the solution dehumidification system comprises a dehumidification device, a circulation pump, the evaporator, a regeneration device and the condenser which are interconnected, and the dehumidification device is configured to remove water vapor in the air through a solution dehumidifier to obtain dehumidified air. The control method comprises: Controlling the operation of the heat pump system and the solution dehumidification system; obtaining the humidity of the dehumidified air; Determining whether the humidity of the dehumidified air meets the requirements; Based on the judgment result, the operating parameters of the heat pump system are selectively adjusted, wherein the operating parameters at least include the throttling temperature.

2. The control method according to claim 1, characterized in that: The step of "selectively adjusting the operating parameters of the heat pump system based on the first judgment result" specifically includes: If the humidity of the dehumidified air is too high, the operating parameters in the heat pump system are adjusted.

3. The control method according to claim 2, characterized in that: The operating parameters include a throttling temperature, and the step of "adjusting the operating parameters in the heat pump system" further includes: Adjust the throttling temperature.

4. The control method according to claim 2, characterized in that: The operating parameters include throttling temperature and evaporation temperature, and the control method further includes: The evaporation temperature is adjusted, and the throttling temperature is adjusted simultaneously with or after each adjustment of the evaporation temperature.

5. The control method according to claim 2, characterized in that: The refrigerant of the heat pump system is a transcritical refrigerant, the operating parameters include exhaust pressure, throttling temperature and evaporation temperature, and the control method further includes: The exhaust pressure is adjusted, and the throttling temperature and the evaporation temperature are adjusted simultaneously with or after each adjustment of the exhaust pressure.

6. The control method according to claim 5, characterized in that: The refrigerant is CO2.

7. The control method according to any one of claims 1 to 6, characterized in that: The control method further comprises: After each adjustment of the operating parameters, determining whether the humidity of the dehumidified air meets the requirements; When or after the humidity of the dehumidified air meets the requirement, calculating the COP value of the entire system under the current operating parameter conditions; The optimal COP value corresponding to the current operating parameter conditions is determined based on the change trend of the COP value.

8. The control method according to claim 7, characterized in that: The operating parameters include throttling temperature, evaporation temperature and exhaust pressure, and the control method further includes: After determining the optimal COP value, compare the optimal COP values ​​corresponding to various exhaust pressures; The exhaust pressure and evaporation temperature corresponding to the maximum COP value are determined as the optimal exhaust pressure and optimal evaporation temperature.

9. The control method according to claim 7, characterized in that: The COP value is determined based on the amount of latent heat change of air entering and exiting the dehumidification device, and the energy consumption of power equipment of the heat pump system and the liquid dehumidification system.

10. The control method according to any one of claims 1 to 6, characterized in that: The heat pump system further comprises an auxiliary condenser, wherein the auxiliary condenser is arranged between the condenser and the throttling device.

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