Transcritical carbon dioxide composite dehumidification system

Abstract

The utility model discloses a transcritical carbon dioxide composite dehumidification system. The transcritical carbon dioxide composite dehumidification system mainly comprises a compressor, a gas cooler, an evaporator, an expansion valve, a heat regenerator, a gas-liquid separator, a rotary dehumidifier, a regeneration fan, a processing fan and an air cooler fan. According to the utility model, the start and stop of the fluorine system are judged by monitoring the air inlet temperature and the target temperature of the evaporator; starting, stopping and energy adjustment of the rotary dehumidifier are judged by monitoring and processing the actual air outlet relative humidity, the actual air outlet air drying ball temperature and the corresponding target value of the draught fan. The loading and unloading of the compressor are judged by monitoring the actual high-pressure value and the target high-pressure value of the compressor; and the increase and decrease degree of the expansion valve is judged by monitoring the actual air suction superheat degree value and the target superheat degree value of the compressor. According to the combined dehumidification unit, the excellent heat exchange characteristic of transcritical cycle of environment-friendly refrigerant carbon dioxide is effectively utilized, good coupling of rotary wheel dehumidification and heat pump dehumidification is achieved, and the application range of the combined dehumidification unit is widened.

Description

Technical Field

[0001] The utility model belongs to the fields of air conditioners and dehumidification, and particularly relates to a transcritical carbon dioxide composite dehumidification system. Background Art

[0002] Today, with the increasingly developed economy, people have higher and higher requirements for industrial and commercial as well as civil dehumidification technologies, including but not limited to the precise and wide-range requirements for the temperature and humidity of the environment in industrial and commercial occasions and even civil buildings.

[0003] At present, the traditional dehumidification application technologies include air-conditioning condensation dehumidification, solution dehumidification and rotary wheel dehumidification. Among them, air-conditioning condensation dehumidification has the advantages of high energy efficiency, energy conservation and emission reduction, and strong applicability, but it is prone to the problem of evaporator frosting due to low-temperature inlet air; rotary wheel dehumidification has the advantages of large dehumidification capacity and operability in low-temperature environments, but it is prone to poor applicability due to high regeneration temperature and has the disadvantages of large regeneration energy consumption and low economy; while the composite dehumidification technology that combines the advantages of the two technologies and overcomes their application limitations has rarely been developed and applied, especially in terms of control logic and control methods. Summary of the Utility Model

[0004] To solve the above technical problems, the utility model provides a transcritical carbon dioxide composite dehumidification system, which uses transcritical carbon dioxide heat pump and rotary wheel composite dehumidification technologies and corresponding control means to solve the application limitations of traditional dehumidification technologies such as evaporator frosting at low temperatures, poor applicability at high regeneration temperatures, and large regeneration energy consumption, so as to achieve the effects of reducing dehumidification energy consumption, broadening the dehumidification application range, improving dehumidification energy efficiency, and saving energy and protecting the environment.

[0005] The technical solution provided by the utility model is as follows:

[0006] A transcritical carbon dioxide composite dehumidification system includes a compressor, a gas cooler, an evaporator, an expansion valve, a regenerator, a rotary wheel dehumidifier, a regeneration fan, a processing fan and an air-cooled cooler fan; the rotary wheel dehumidifier includes a rotary wheel, a dehumidifying and drying material and a regeneration electric heater;

[0007] The outlet of the compressor is connected to the inlet of the gas cooler, the outlet of the gas cooler is connected to the first inlet of the regenerator, the first outlet of the regenerator is connected to the inlet of the expansion valve, the outlet of the expansion valve is connected to the first inlet of the evaporator, the first outlet of the evaporator is connected to the second inlet of the regenerator, and the second outlet of the regenerator is connected to the inlet of the compressor; the second inlet of the evaporator is for ambient air intake, the second outlet of the evaporator is connected to the first inlet of the rotary wheel, the first outlet of the rotary wheel is connected to the inlet of the processing fan, and the outlet of the processing fan is connected to the place where dehumidification is required; the second inlet of the gas cooler is connected to the ambient air intake, the second outlet of the gas cooler is respectively connected to the second inlet of the rotary wheel and the inlet of the air-cooler fan, the second outlet of the rotary wheel is connected to the inlet of the regeneration fan, the outlet of the regeneration fan is connected to the external environment, and the outlet of the air-cooler fan is connected to the external environment.

[0008] Preferably, the first outlet of the regenerator is connected to the inlet of the expansion valve through a first stop valve, and the outlet of the expansion valve is connected to the first inlet of the evaporator through a second stop valve.

[0009] Further, a temperature and humidity sensor is provided at the second inlet of the evaporator.

[0010] Further, temperature sensors are provided at both the second inlet and the second outlet of the gas cooler.

[0011] Further, a temperature and humidity sensor is provided on the pipeline connecting the first outlet of the rotary wheel and the processing fan, and a temperature sensor is provided on the pipeline connecting the second outlet of the rotary wheel and the regeneration fan.

[0012] Further, a pressure sensor and a temperature sensor are provided on the pipeline connecting the outlet of the compressor and the gas cooler.

[0013] Preferably, a gas-liquid separator is further provided between the regenerator and the compressor. The inlet of the gas-liquid separator is connected to the second outlet of the regenerator, and the outlet of the gas-liquid separator is connected to the inlet of the compressor.

[0014] Further, a pressure sensor and a temperature sensor are also provided on the pipeline connecting the outlet of the gas-liquid separator and the compressor.

[0015] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0016] 1. The utility model couples the transcritical carbon dioxide heat pump technology with the dehumidifying rotary wheel technology, operates the dehumidifying rotary wheel in a low-temperature environment, operates the carbon dioxide heat pump and the dehumidifying rotary wheel in a composite manner in a relatively high-temperature environment, and uses the relatively high heat recovery amount of carbon dioxide for the regeneration of the rotary wheel to solve the application limitations of traditional refrigeration and dehumidification technologies such as frosting of the evaporator at low temperatures, poor applicability under relatively high regeneration temperatures of the rotary wheel dehumidification, and high regeneration energy consumption, and achieves effects such as reducing dehumidification energy consumption, broadening the dehumidification application range, improving dehumidification energy efficiency, reducing costs, and saving energy and protecting the environment.

[0017] 2. By monitoring the relative humidity value of the processed air and the dry-bulb temperature of the regeneration air, comparing the relative humidity value of the processed air with the target relative humidity value of the processed air and the relative humidity difference, and comparing the dry-bulb temperature of the regeneration air with the target dry-bulb temperature and the temperature difference, it is used as the determination condition for the increase and decrease of the electric heating load and maintaining the current load, so as to achieve real-time control of the relative humidity of the processed air and the dry-bulb temperature of the regeneration air, and provide the final energy guarantee for the coupled operation of the heat pump dehumidification and the rotary wheel dehumidification. Then, under the condition of maintaining an appropriate dry-bulb temperature of the processed air, the target control of the dehumidification amount of the processed air in single-rotary wheel dehumidification or composite dehumidification is realized.

[0018] 3. By monitoring the inlet air temperature of the evaporator and comparing the inlet air temperature of the evaporator with the target temperature, it is used as the determination condition for the startup mode, so as to select an appropriate dehumidification mode according to different inlet air conditions, thus providing a guarantee for meeting the dehumidification requirements under different environmental conditions, and then broadening the applicable range of the dehumidification system.

[0019] 4. By monitoring the high-pressure value, comparing the measured high-pressure value, the system high-pressure target value and the pressure difference, it is used as the determination condition for the compressor to increase and decrease the load and maintain the current energy load, and comparing the measured suction superheat value, the assigned suction superheat value and the superheat difference, it is used as the determination condition for the expansion valve to open and close and maintain the current opening degree, so as to achieve real-time control of the output energy of the compressor and the refrigerant flow rate of the heat pump system, and then realize the precise control of the high pressure of the heat pump system. And under the condition of maintaining the stable operation of the transcritical carbon dioxide heat pump, the excellent control of the high-performance dehumidification and the reuse of the heat recovery amount of the carbon dioxide heat pump is realized.

[0020] 5. The utility model adopts a variable-frequency compressor, which provides a sustainable energy regulation guarantee for adapting to the dehumidification amount requirements under different working conditions. It adopts a variable-frequency air-cooled condenser fan and a variable-frequency evaporator fan, which provides a variable air volume condition for the system to adapt to different working condition requirements and maintain normal low pressure and high pressure, thus being conducive to the stable and reliable operation of the system. Description of the Drawings

[0021] The accompanying drawings are used to provide a further understanding of the present utility model and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model and do not constitute a limitation to the present utility model.

[0022] Figure 1 It is the system schematic diagram of the dehumidification system provided by an embodiment of the present utility model;

[0023] Figure 2 It is the schematic diagram of the startup control process provided by an embodiment of the present utility model;

[0024] Figure 3 It is the schematic diagram of the shutdown control process provided by an embodiment of the present utility model;

[0025] Figure 4 It is the schematic diagram of the energy regulation control process provided by an embodiment of the present utility model;

[0026] Figure 5 It is the schematic diagram of the expansion valve control process provided by an embodiment of the present utility model;

[0027] Figure 6 It is the schematic diagram of the rotary wheel dehumidification control process provided by an embodiment of the present utility model.

[0028] Among them, each reference numeral represents:

[0029] 1 - Compressor, 2 - Gas cooler, 3 - Evaporator, 4 - Expansion valve, 5 - Regenerator, 6 - Gas - liquid separator, 7 - Rotary wheel, 8 - Regeneration fan, 9 - Processing fan, 10 - Air cooler fan, 11 - First stop valve, 12 - Second stop valve, 13 - Regeneration electric heater, 14 - Second temperature sensor, 15 - First temperature sensor, 16 - Second pressure sensor, 17 - Fifth temperature sensor, 18 - First pressure sensor, 19 - Fourth temperature sensor, 20 - First temperature - humidity sensor, 21 - Second temperature - humidity sensor, 22 - Third temperature sensor. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0031] Such as Figure 1As shown in the figure, this embodiment provides a transcritical carbon dioxide composite dehumidification system, which is divided into a fluorine system, a wind system and a rotary dehumidifier, and mainly includes: a compressor 1, a gas cooler 2, an evaporator 3, an expansion valve 4, a regenerator 5, a gas-liquid separator 6, a rotary dehumidifier, a regeneration fan 8, a processing fan 9 and an air cooler fan 10.

[0032] Fluorine system: The outlet of the compressor 1 is connected to the inlet of the gas cooler 2, the outlet of the gas cooler 2 is connected to the first inlet of the regenerator 5, the first outlet of the regenerator 5 is connected to the inlet of the expansion valve 4 through the first stop valve 11, the outlet of the expansion valve 4 is connected to the first inlet of the evaporator 3 through the second stop valve 12, the first outlet of the evaporator 3 is connected to the second inlet of the regenerator 5, the second outlet of the regenerator 5 is connected to the inlet of the gas-liquid separator 6, and the outlet of the gas-liquid separator 6 is connected to the inlet of the compressor 1.

[0033] Wind system: The second inlet of the evaporator 3 is connected to the ambient air inlet through a duct, the second outlet of the evaporator 3 is connected to the first inlet of the rotary wheel 7 through a duct, the first outlet of the rotary wheel 7 is connected to the inlet of the processing fan 9 through a duct, and the outlet of the processing fan 9 is connected to the place where dehumidification is required through a duct; the second inlet of the gas cooler 2 is connected to the ambient air inlet through a duct, the second outlet of the gas cooler 2 is connected to the second inlet of the rotary wheel 7 through a duct on one side and to the inlet of the air cooler fan 10 on the other side, the second outlet of the rotary wheel 7 is connected to the inlet of the regeneration fan 8 through a duct, the outlet of the regeneration fan 8 is connected to the external environment through a duct, and the outlet of the air cooler fan 10 is connected to the external environment through a duct. The rotary dehumidifier includes a rotary wheel 7, a dehumidifying and drying material, a regeneration electric heater 13, etc.

[0034] Based on the above system, the working process of heat pump dehumidification is as follows:

[0035] The refrigerant with low temperature and low pressure is compressed by the compressor 1, and the compressed high-temperature and high-pressure gas enters the gas cooler 2 to exchange heat with the introduced air and is cooled. The cooled refrigerant enters the regenerator 5 to exchange heat with the low-temperature and low-pressure refrigerant from the evaporator 3 and is further cooled. The further cooled refrigerant is throttled by the expansion valve 4 and enters the evaporator 3 to exchange heat with the wet air to be treated and evaporates and absorbs heat to become a low-temperature and low-pressure gas. Then it enters the regenerator 5 to exchange heat with the relatively higher-temperature refrigerant from the gas cooler 2 and is further superheated, and finally returns to the compressor 1 to complete the cycle. Using the evaporator 3 as the condensation dehumidification device, the introduced wet air to be treated is cooled to the dew point temperature or below, the water vapor in the wet air is precipitated and condensed into water, the absolute moisture content of the wet air is reduced, and thus the relative humidity of the air is reduced to achieve the purpose of efficient dehumidification.

[0036] Furthermore, the working process of composite dehumidification is as follows:

[0037] After the wet air to be processed is dehumidified for the first time by the evaporator 3, it enters the dehumidification area of the rotary dehumidifier 7 and is dehumidified by the moisture absorbent in the dehumidification area to absorb moisture, so as to achieve the purpose of secondary dehumidification and complete the working goal of composite dehumidification. On the other hand, the introduced air heated by the gas cooler 2, a part of it is discharged to the external environment by the air cooler fan 10, and the other part enters the rotary wheel 7 and the regeneration electric heater 13 in the form of regeneration air to complete the regeneration of the moisture absorbent, so as to achieve the purpose of converting the waste heat of the gas cooler 2 into regeneration heat and saving the power consumption of electric heating.

[0038] The control process of the composite dehumidification system provided by this embodiment mainly includes startup control, shutdown control, compressor energy regulation control, expansion valve control, rotary dehumidifier control, auxiliary control and protection.

[0039] (1) Startup control

[0040] As Figure 2As shown in the figure, first, power on the unit. The human-machine interface of the system receives the startup command and checks whether the software and hardware are normal and whether the unit has a fault alarm. If it is abnormal or there is an alarm, startup is not allowed, and it is repeatedly checked until the software and hardware are normal and there is no fault alarm. Then, determine whether the inlet air temperature th of the evaporator is higher than the target value tj (the default value of tj is 20, which can be changed according to actual needs). When th≥tj, the fluorine system and the rotary dehumidifier perform combined dehumidification; when th<tj, the rotary dehumidifier works alone. Next, after determining that the fluorine system and the rotary dehumidifier perform combined dehumidification, the compressor crankshaft heating belt or oil heating can be started immediately or with a delay. Subsequently, delay n1 seconds to turn on the air-cooled condenser fan and the regeneration fan. The default value of n1 is 5 (which can be changed according to actual needs). The initial value of the air-cooled condenser fan is 1500 m3 / h (which can be changed according to actual needs), and the regeneration fan operates at a fixed frequency. Then delay n2 seconds to turn on the processing fan. The initial value of the processing fan is 1100 m3 / h (which can be changed according to actual needs), and the air volume value can be adjusted through the human-machine interface according to the processing air volume requirement. The default value of n2 is 30, which can be changed according to actual needs. Then delay n3 seconds to detect and determine whether the suction pressure (high pressure) meets the startup and loading conditions, that is, the suction pressure needs to be greater than or equal to 4 Mpar (which can be changed according to actual needs), and whether the dry bulb temperature of the inlet air of the evaporator meets the determination conditions, that is, the dry bulb temperature of the inlet air of the evaporator needs to be greater than or equal to 20 °C (which can be changed according to actual needs). After both are met, the next step can be carried out; otherwise, continue to detect and determine. The default value of n3 is 5, which can be changed according to actual needs. Then delay n4 seconds for the expansion valve to be powered on. The starting step of the expansion valve is 200 (which can be changed according to actual needs). The crankshaft heating belt or oil heating is powered on for more than 30 minutes (which can be changed according to actual needs) and then powered off; otherwise, wait. After meeting this condition, delay n5 seconds to start the compressor. The starting speed is the default value of 2400 revolutions per minute (which can be changed according to actual needs). The default values of n4 and n5 are both 5, and both can be changed according to actual needs. At this point, the startup of the carbon dioxide heat pump is completed. Then delay n6 seconds to start the rotary dehumidifier, and then delay n7 seconds to turn on the rotary dehumidifier electric heater. The default values of n6 and n7 are 5 and 30 respectively, and both can be changed according to actual needs. At this point, the startup of the carbon dioxide heat pump combined dehumidification unit is completed. After determining that the rotary dehumidifier works alone, delay n1 seconds to turn on the regeneration fan. The default value of n1 is 5, which can be changed according to actual needs. Then delay n2 seconds to turn on the processing fan. The default value of n2 is 30, which can be changed according to actual needs. Then delay n6 seconds to start the rotary wheel, and then delay n7 seconds to turn on the rotary dehumidifier electric heater. The default values of n6 and n7 are 5 and 30 respectively, and both can be changed according to actual needs. At this point, the startup of the rotary dehumidification unit is completed.

[0041] (2) Shutdown control

[0042] Such as Figure 3As shown, the human-machine interface accepts the shutdown command (the shutdown process is not logically controlled by the operating stage). The compressor speed is reduced to the minimum allowable speed and then the compressor is shut down. After a delay of 30 seconds, the expansion valve is closed, and the time value is adjustable. After a delay of m1 seconds, the regeneration heater is turned off. The default value of m1 is 5 for all, and all can be changed according to actual requirements. After a delay of m2 seconds, the rotary dehumidifier is turned off. The default value of m2 is 600 for all, and all can be changed according to actual requirements. After a delay of m3 seconds, the regeneration fan is turned off. The default value of m3 is 60 for all, and it can be changed according to actual requirements. After a delay of m4 seconds, the air-cooled condenser fan is turned off. The default value of m4 is 5 for all, and all can be changed according to actual requirements. After a delay of m5 seconds, the processing fan is turned off. The default value of m5 is 5 for all, and all can be changed according to actual requirements.

[0043] (3) Compressor energy regulation control

[0044] As Figure 4 shown, after the whole machine starts up successfully, it enters the determination of compressor loading and unloading and maintaining the current energy load:

[0045] When the measured high-pressure value P ≥ the high-pressure target value Ps + the pressure difference D3, the compressor is in the emergency stop area, and all compressors should be unloaded and shut down immediately in sequence;

[0046] When the high-pressure target value Ps + the pressure difference D3 > the measured high-pressure value P ≥ the high-pressure target value Ps + the pressure difference D2, the compressor is in the unloading area. If only one compressor is running currently, it unloads by 200 (can be changed according to actual requirements) every 60 seconds (can be changed according to actual requirements) until the minimum speed. If the pressure continues to rise and exceeds the emergency stop value, it shuts down. If two or more compressors are running in parallel currently, all compressors are unloaded in sequence (the speed is reduced to the lowest value) until they are shut down, and the unloading operation is carried out according to the above mode;

[0047] When the high-pressure target value Ps + pressure difference D2 > measured high-pressure value P > high-pressure target value Ps or high-pressure target value Ps ≥ measured high-pressure value P > high-pressure target value Ps - pressure difference D1, the compressor is in the holding area, maintaining the current compressor energy load operation state to a certain extent and fine-tuning according to a certain pattern. If U(n) is positive, the compressor unloads, reducing the speed according to the absolute value of the current U(n), and gradually unloading every 40 seconds (which can be changed according to actual needs); if U(n) is negative, the compressor loads, increasing the speed by the absolute value of the current U(n), and gradually loading every 40 seconds (which can be changed according to actual needs). Among them, U(n) = F(P(n), Ps) = Kp * (P(n) - Ps), U(n) is the system target load increase or decrease value at the nth moment, P(n) is the system high-pressure value at the nth moment, Ps is the system high-pressure target value, and Kp is the set proportional coefficient value. The above formula is a preferred solution, but is not limited to this formula, and can be other similar functional formulas including the system high-pressure target value Ps and the system high-pressure value P(n) at the nth moment.

[0048] When the measured high-pressure value P ≤ high-pressure target value Ps - pressure difference D1, the compressor is in the loading area. If no compressor is running, one compressor is started, from the lowest frequency speed of 2400 revolutions per minute (which can be changed according to actual needs), and loaded by 200 (which can be changed according to actual needs) every 60 seconds (which can be changed according to actual needs) to the compressor speed corresponding to the high-pressure target value. Specifically, y = f(x) = -2 * 10^(-12) * x * x + 240 * x + 480x, where x is the system high-pressure target value Ps and y is the compressor speed value corresponding to x. The above formula is a preferred solution, but is not limited to this formula, and can be other similar functional formulas including the system high-pressure target value Ps. If it is still in the loading area, it is loaded by 200 (which can be changed according to actual needs) every 60 seconds (which can be changed according to actual needs) until the highest speed value, with a default of 3000 revolutions, until it enters the holding area and stops loading, and is adjusted according to the energy regulation mode in the holding area.

[0049] Among them, the default value of Ps is 10 MPa, the default value of D2 is 0.3 MPa, the default value of D1 is 0.5 MPa, the default value of D3 is 2.5 MPa, D3 > D2, and Ps, D1, D2, D3 can all be changed according to actual needs.

[0050] (4) Expansion valve control

[0051] Such as Figure 5As shown in the figure, after the whole machine starts up successfully, the compressor starts and is loaded to the compressor speed corresponding to the high-pressure target value. Then, the initial control of the expansion valve is entered. The expansion valve starts to be adjusted from the initial opening of 200 steps (which can be modified according to actual requirements), and the valve is opened or closed step by step by 2 steps (which can be modified according to actual requirements) until the opening of the valve corresponding to the high-pressure target value. Specifically, y1 = f(x1) = -3.214x1 * x1 + 75.75x1 - 250.8, where x1 is the system high-pressure target value Ps, and y1 is the number of steps of the expansion valve corresponding to x1. The above formula is a preferred solution, but it is not limited to this formula, and it can be other similar functional formulas including the system high-pressure target value Ps. Then, the determination of the expansion valve opening, holding, and closing is entered:

[0052] When the suction superheat value T' ≥ the suction superheat assigned value T's + the superheat difference D'2, the expansion valve is in the valve-opening area, and the valve is opened step by step by 2 steps every 40 seconds (which can be modified according to actual requirements). If it has been in the valve-opening area, the valve is opened to the maximum value;

[0053] When the suction superheat assigned value T's + the superheat difference D'2 > the suction superheat value T' > the suction superheat assigned value T's or the suction superheat assigned value T's ≥ the suction superheat value T' > the suction superheat assigned value T's - the superheat difference D'1, the expansion valve is in the holding area. The expansion valve maintains the current opening to a certain extent. When the compressor load remains unchanged for 15 minutes (which can be modified according to actual requirements) and the exhaust pressure does not reach the high-pressure target value Ps, the valve is closed step by step by 2 steps (which can be modified according to actual requirements) until the exhaust pressure reaches the high-pressure target value Ps and the valve closing stops and maintains the current opening;

[0054] When the suction superheat value T' ≤ the suction superheat assigned value T's - the superheat difference D'1, the expansion valve is in the valve-closing area, and the valve is closed step by step by 2 steps every 40 seconds (which can be modified according to actual requirements). If it has been in the valve-closing area, the valve is closed to the minimum value.

[0055] Among them, the default value of T's is 10, the default value of D'1 is 10, the default value of D'2 is 20, and T's, D'1, and D'2 can all be modified according to actual requirements.

[0056] (5) Rotary wheel dehumidification control

[0057] As Figure 6 shown in the figure, after the whole machine starts up successfully, after a delay of Q1 minutes, the wet bulb temperature determination conditions and mode one for the regeneration electric heating of the dehumidifier to increase load, maintain, and reduce load are entered:

[0058] When the dry bulb temperature of the processed air Td ≥ the target dry bulb temperature Td' + temperature difference D'4, the regenerative electric heating is unloaded according to a certain pattern, that is, it is downshifted one by one every 1 minute (which can be changed according to actual requirements) or reduced by 1000w (which can be changed according to actual requirements). If it has been in this condition, it will be unloaded until the minimum gear or the minimum load is reached;

[0059] When the dry bulb temperature of the processed air Td ≤ the target dry bulb temperature Td' - temperature difference D'5, the regenerative electric heating is loaded or upshifted according to a certain pattern, that is, it is upshifted one by one every 1 minute (which can be changed according to actual requirements) or increased by 1000w (which can be changed according to actual requirements). If it has been in this condition, it will be loaded until the maximum gear or the maximum load is reached;

[0060] When the target dry bulb temperature Td' + temperature difference D'4 > the dry bulb temperature of the processed air Td > the target dry bulb temperature Td' - temperature difference D'5, the regenerative electric heating is upshifted or downshifted or loaded or unloaded or maintains the current load according to the judgment condition and mode two:

[0061] When the relative humidity value of the processed air S' ≥ the target relative humidity value of the processed air S's + humidity difference D'3, the regenerative electric heating is in the upshift area, and it is upshifted one by one every 5 minutes (which can be changed according to actual requirements) or increased by 500w (which can be changed according to actual requirements). If it has been in the upshift area, the dehumidifier will be turned to the maximum gear or the maximum load;

[0062] When the target relative humidity value of the processed air S's + humidity difference D'3 > the relative humidity value of the processed air S' > the target relative humidity value of the processed air S's - humidity difference D'3, the regenerative electric heating is in the holding area, and the current gear or load is maintained;

[0063] When the relative humidity value of the processed air S' ≤ the target relative humidity value of the processed air S's - humidity difference D'3, the regenerative electric heating is in the downshift area, and it is downshifted one by one every 5 minutes (which can be changed according to actual requirements) or reduced by 500w (which can be changed according to actual requirements). If it has been in the downshift area, the dehumidifier will be turned to the minimum gear or the minimum load.

[0064] Among them, the default value of Q1 is 40, the default value of S's is 25%, the default value of D'1 is 10, the default value of Td' is 100, the default value of D'4 is 30, and the default value of D'5 is 85, all of which can be changed according to actual requirements.

[0065] (6) Auxiliary control and protection

[0066] Auxiliary control and protection mainly involve the control of air cooler fans, process fans, high regeneration temperature protection, high regeneration temperature alarm and compressor high and low pressure protection, etc., which are used for the start and stop and operation of carbon dioxide heat pumps and rotary dehumidification: air cooler fan control, after the compressor starts and runs for 15 minutes (can be changed according to actual needs), the air cooler fan increases or decreases the air volume from the initial opening of 1500m3 / h (can be changed according to actual needs), and increases or decreases the air volume by 50m3 / h (can be changed according to actual needs) every 5 seconds (can be changed according to actual needs) to the air volume of the fan corresponding to the high pressure target value. Specifically, y2=f(x2)=7.407x2*x2*x2-191.2x2*x2+1904x2-5986, where x2 is the system high pressure target value Ps, and y2 is the fan air volume corresponding to x2. The above formula is a preferred solution, but is not limited to this formula, and may be other similar functional formulas including the system high pressure target value Ps. Evaporator low temperature protection, the unit is shut down or running, when the evaporator evaporation temperature is ≤-21°C (can be changed according to actual needs), the alarm will be delayed for 3 seconds (can be changed according to actual needs) and the alarm information will be displayed. The compressor should not be started or shut down in time; regeneration temperature high protection, during the operation of the rotary dehumidifier, when the regeneration air dry bulb temperature is ≥140°C (can be changed according to actual needs), the regeneration electric heating will reduce the load according to a certain mode, that is, every 1 minute (can be changed according to actual needs) downshift or 1000w (can be changed according to actual needs) reduction. If it is always in this condition, it will continue to reduce the load to the minimum gear or minimum load. If the regeneration air dry bulb temperature is ≤130°C (can be changed according to actual needs) The dehumidifier should not be started or stopped in time, and the regeneration electric heating should stop heating; the compressor high and low pressure protection, during the operation of the compressor, the suction pressure ≤1.8MPa (can be changed according to actual needs) or the exhaust pressure ≥13mpa (can be changed according to actual needs), the alarm will be displayed after a delay of 3s (can be changed according to actual needs), and the compressor should be stopped in time.

[0067] In some embodiments, auxiliary control and protection also includes compressor overheat protection, compressor low pressure high protection, compressor current protection, compressor exhaust temperature high protection, compressor reverse protection, compressor pressure difference unestablished protection and other modules used to maintain and protect the stable and safe operation of the unit.

[0068] In the embodiment of the present utility model, the compressor is a variable-frequency compressor, but is not limited to the variable-frequency type, and can also be a stepless regulation screw compressor or a device with a similar function; the expansion valve is an electronic expansion valve, but is not limited to the electronic expansion valve, and can also be a controllable device with a similar function that plays a throttling role; the evaporator is a stainless steel finned heat exchanger, but is not limited to the stainless steel finned heat exchanger, and can also be a microchannel heat exchanger or a device with a similar function; the gas cooler is a stainless steel finned heat exchanger or a device with a similar function, but is not limited to the stainless steel finned heat exchanger, and can also be a microchannel heat exchanger or a device with a similar function; the regenerator is a shell-and-tube heat exchanger, but is not limited to the shell-and-tube heat exchanger, and can also be a plate heat exchanger or a device with a similar function; the air cooler fan is a variable-frequency fan, but is not limited to the variable-frequency fan, and can also be a device with adjustable air volume with a similar function; the treatment fan is a variable-frequency fan, but is not limited to the variable-frequency fan, and can also be a device with adjustable air volume with a similar function; the regeneration fan is a fixed-frequency fan, but is not limited to the fixed-frequency fan, and can also be a variable-frequency fan or a device with a similar function.

[0069] In the embodiment of the present utility model, a first temperature and humidity sensor 20 is provided at the air inlet of the evaporator 3, which can display the dry bulb temperature, wet bulb temperature and relative humidity of the gas, but is not limited to the temperature and humidity sensor, and can also be one or more instruments and meters with a similar function; a second temperature and humidity sensor 21 is provided at the first outlet of the runner, which can display the dry bulb temperature, wet bulb temperature and relative humidity of the gas, but is not limited to the temperature and humidity sensor, and can also be one or more instruments and meters with a similar function; a first temperature sensor 15 and a second temperature sensor 14 are provided at the inlet and outlet of the gas cooler 2, but is not limited to the temperature sensor, and can also be a temperature and humidity sensor or one or more instruments and meters with a similar function; a third temperature sensor 22 is provided at the second outlet of the runner, but is not limited to the temperature sensor, and can also be a temperature and humidity sensor or one or more instruments and meters with a similar function.

[0070] In this embodiment, the control system determines the start and stop of the fluorine system by comparing the inlet air temperature of the evaporator with the target temperature. The inlet air temperature comes from the collected value of the first temperature and humidity sensor, and the target temperature comes from the set value within the logic. By processing the comparison between the actual outlet air relative humidity of the fan and the target relative humidity, and the comparison between the actual outlet air dry bulb temperature and the target dry bulb temperature, it determines the start and stop and adjustable capacity of the rotary dehumidifier. The actual outlet air relative humidity comes from the collected value of the second temperature and humidity sensor, the actual outlet air dry bulb temperature comes from the collected value of the second temperature and humidity sensor, and the target relative humidity and the target dry bulb temperature come from the set values of the human-machine interface. By comparing the actual high pressure value of the compressor with the target high pressure value, it determines the loading and unloading of the compressor. The actual high pressure value comes from the collected value of the second pressure sensor, and the target high pressure value comes from the set value of the human-machine interface. By comparing the actual suction superheat value of the compressor with the target superheat value, it determines the adjustment degree of the expansion valve. The actual suction superheat comes from the difference between the collected value of the fourth temperature sensor and the evaporation temperature corresponding to the collected value of the first pressure sensor, and the target superheat value comes from the set value of the human-machine interface.

[0071] The collected values of the first temperature and humidity sensor in the control system have application functions in display, control, and alarm. The collected value of the first temperature sensor has an application function in display. The collected value of the second temperature sensor has application functions in display and alarm. The collected value of the second temperature and humidity sensor has application functions in display and control. The collected value of the third temperature sensor has application functions in display and alarm. The collected value of the fourth temperature sensor has application functions in display and control. The collected value of the fifth temperature sensor has application functions in display and alarm. The collected value of the first pressure sensor has application functions in display, control, and alarm. The collected value of the second pressure sensor has application functions in display, control, and alarm. The control system includes a start-up control module, a shutdown control module, a compressor energy regulation control module, an expansion valve control module, a rotary dehumidification control module, an auxiliary control and protection module.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. For the sake of simplicity, they are not provided in detail; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A transcritical carbon dioxide composite dehumidification system, characterized in that: It includes a compressor, a gas cooler, an evaporator, an expansion valve, a regenerator, a rotary dehumidifier, a regeneration fan, a processing fan and an air cooler fan; the rotary dehumidifier includes a rotary wheel, a dehumidifying and drying material and a regeneration electric heater; The outlet of the compressor is connected to the inlet of the gas cooler, the outlet of the gas cooler is connected to the first inlet of the regenerator, the first outlet of the regenerator is connected to the inlet of the expansion valve, the outlet of the expansion valve is connected to the first inlet of the evaporator, the first outlet of the evaporator is connected to the second inlet of the regenerator, and the second outlet of the regenerator is connected to the inlet of the compressor; the second inlet of the evaporator is used for ambient air intake, the second outlet of the evaporator is connected to the first inlet of the rotor, the first outlet of the rotor is connected to the inlet of the process fan, and the outlet of the process fan is connected to the place required for dehumidification; the second inlet of the gas cooler is connected to the ambient air intake, the second outlet of the gas cooler is respectively connected to the second inlet of the rotor and the inlet of the air cooler fan, the second outlet of the rotor is connected to the inlet of the regeneration fan, the outlet of the regeneration fan is connected to the external environment, and the outlet of the air cooler fan is connected to the external environment.

2. A transcritical carbon dioxide composite dehumidification system according to claim 1, characterized in that: The first outlet of the regenerator is connected to the inlet of the expansion valve through a first stop valve, and the outlet of the expansion valve is connected to the first inlet of the evaporator through a second stop valve.

3. A transcritical carbon dioxide composite dehumidification system according to claim 1, characterized in that: The second inlet of the evaporator is provided with a temperature and humidity sensor.

4. A transcritical carbon dioxide composite dehumidification system according to claim 1, characterized in that: The second inlet and the second outlet of the gas cooler are both provided with temperature sensors.

5. A transcritical carbon dioxide composite dehumidification system according to claim 1, characterized in that: A temperature and humidity sensor is provided on a connecting pipeline between the first outlet of the rotor and the processing fan, and a temperature sensor is provided on a connecting pipeline between the second outlet of the rotor and the regeneration fan.

6. A transcritical carbon dioxide composite dehumidification system according to claim 1, characterized in that: A pressure sensor and a temperature sensor are provided on the connecting pipeline between the outlet of the compressor and the gas cooler.

7. A transcritical carbon dioxide composite dehumidification system according to claim 1, characterized in that: A gas-liquid separator is also provided between the regenerator and the compressor, the inlet of the gas-liquid separator is connected to the second outlet of the regenerator, and the outlet of the gas-liquid separator is connected to the inlet of the compressor.

8. A transcritical carbon dioxide composite dehumidification system according to claim 7, characterized in that: A pressure sensor and a temperature sensor are also provided on the connecting pipeline between the outlet of the gas-liquid separator and the compressor.

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