Water-cooled deep dehumidification air conditioner and control method thereof

Abstract

The invention discloses a water-cooled deep dehumidification air conditioner and a control method thereof. The water-cooled deep dehumidification air conditioner comprises an air inlet section, a filtering section, a first-stage refrigerating section, a second-stage refrigerating section, a condensation reheating section, an electric heating section, a humidifying section and an air feeder section which are sequentially connected along an air path. The first-stage refrigeration section, the second-stage refrigeration section and the condensation reheating section each comprise an independent refrigeration system, the water system comprises a first water valve, a second water valve and a third water valve, and the water cooling heat exchangers are connected with the water valves and connected to the water system in parallel. According to the control method of the water-cooled deep dehumidification air conditioner, the dehumidification starting stage number is judged by comparing the air supply moisture content with the set moisture content, and the refrigerating capacity is adjusted by adjusting the frequency of the third-stage compressor. The limitation of a traditional air-cooled air conditioner is made up, and the dehumidification capacity and precision of the air conditioner are improved. The control logic is optimized, so that the adaptability of the air conditioner is higher, the error-tolerant rate is higher, and the long-term and stable operation of the dehumidification air conditioner is ensured.

Description

Technical Field

[0001] The present invention relates to a water-cooled deep dehumidification air conditioner, and also relates to a control method for the water-cooled deep dehumidification air conditioner, belonging to the technical field of air conditioning. Background Art

[0002] In some places with high requirements for air humidity, such as underground projects, it is usually low temperature and high humidity (for example, the enthalpy difference between the inside and outside of the cave depot is large in summer). Ordinary air conditioners are difficult to reduce the dew point of air (including return air and fresh air) to the non-condensing level. Therefore, the dehumidification capacity of traditional air-cooled air conditioners often cannot meet the requirements. These places not only need to reduce the humidity to a lower level, but also are restricted by the installation space and the place (for example, underground projects do not have the conditions for installing air-cooled external units). Therefore, it is difficult to ensure the normal operation of equipment, the proper storage of items and the comfortable environment for personnel.

[0003] In the Chinese patent application with the application number 202510055881.5, a mine heat and humidity independent regulation system and method are disclosed. The technical solution includes a ventilation system; the ventilation system sequentially passes the mine air flow through a dust removal system, a dehumidification system, and a cooling system to obtain clean, low-temperature and low-humidity air. The heat recovery system collects the waste heat in the cooling system, the dehumidification system, the dust removal system, and the mine water collection device. The power system provides circulating power for the water circulation of the cooling system, the dehumidification system, the mine water collection device, and the dust removal system to maintain the stable operation of the system. The intelligent control system monitors the operating parameters of the cooling system, the dehumidification system, the dust removal system, the heat recovery system, and the ventilation system, as well as the mine parameters, realizes adjustable supply air parameters, operating parameters, and standby equipment, and realizes safety warning through the central controller. This system and method have the ability to independently regulate temperature and humidity, can make full use of waste heat, and have low system energy consumption.

[0004] Traditional air-cooled air conditioners have certain limitations in dehumidification. Their dehumidification efficiency is limited and it is difficult to meet the rapid dehumidification requirements in high-humidity environments. Although existing water-cooled air conditioners have certain advantages in refrigeration, their deep dehumidification function still needs to be improved: on the one hand, the dehumidification accuracy of some systems is insufficient and it is difficult to meet the scenarios with strict humidity requirements; on the other hand, the existing control systems have low intelligence and cannot adjust the operating parameters in real time and accurately according to the change of environmental humidity, resulting in unstable dehumidification effect. Therefore, it is of great practical significance to develop a water-cooled air conditioner that can achieve deep dehumidification, high energy efficiency, and has intelligent control functions. Summary of the Invention

[0005] The primary technical problem to be solved by the present invention is to provide a water-cooled deep dehumidification air conditioner.

[0006] Another technical problem to be solved by the present invention is to provide a control method for the above-mentioned water-cooled deep dehumidification air conditioner.

[0007] To achieve the above technical objectives, the present invention adopts the following technical solutions: According to the first aspect of the embodiments of the present invention, there is provided a water-cooled deep dehumidification air conditioner, including an air inlet section, a filtration section, a first-stage refrigeration section, a second-stage refrigeration section, a condensation reheating section, an electric heating section, a humidification section, a blower section, and a water system. Among them, The air inlet section, the filtration section, the first-stage refrigeration section, the second-stage refrigeration section, the condensation reheating section, the electric heating section, the humidification section, and the blower section are sequentially connected along the air path; The first-stage refrigeration section, the second-stage refrigeration section, and the condensation reheating section all include independent refrigeration systems; The water system includes a controller, a first water valve, a second water valve, a third water valve, a first temperature sensor, a second temperature sensor, and a third temperature sensor; the water system is connected to the first-stage refrigeration section through the first water valve, and the first temperature sensor obtains the inlet and outlet water temperatures of the first-stage refrigeration section; the water system is connected to the second-stage refrigeration section through the second water valve, and the second temperature sensor obtains the inlet and outlet water temperatures of the second-stage refrigeration section; the water system is connected to the condensation reheating section through the third water valve, and the third temperature sensor obtains the inlet and outlet water temperatures of the condensation reheating section.

[0008] Preferably, the air inlet section is an air inlet device, including an air inlet section temperature sensor and an air inlet section relative humidity sensor, for introducing external air and measuring the inlet air temperature and inlet air relative humidity; The filtration section is an air filtration device; the electric heating section is an air heating device; the humidification section is an air humidification device; The blower section is a air supply device, including a blower, a blower section temperature sensor, and a blower section relative humidity sensor, for supplying air and measuring the supply air temperature and supply air relative humidity.

[0009] Preferably, the first-stage refrigeration section includes a first compressor unit, a first water-cooled heat exchanger, a first liquid storage tank, a first evaporator, and a first gas-liquid separator; among them, The outlet of the first compressor unit is connected to the refrigerant pipeline inlet of the first water-cooled heat exchanger, the refrigerant pipeline outlet of the first water-cooled heat exchanger is connected to the inlet of the first liquid storage tank, the outlet of the first liquid storage tank is connected to the inlet of the first evaporator, the outlet of the first evaporator is connected to the inlet of the first gas-liquid separator, and the outlet of the first gas-liquid separator is connected to the inlet of the first compressor unit; The first water valve is connected to the heat exchange medium pipeline of the first water-cooled heat exchanger.

[0010] Preferably, the second-stage refrigeration section includes a second compressor unit, a second water-cooled heat exchanger, a second liquid storage tank, a second evaporator, and a second gas-liquid separator; wherein, The outlet of the second compressor unit is connected to the refrigerant pipeline inlet of the second water-cooled heat exchanger, the refrigerant pipeline outlet of the second water-cooled heat exchanger is connected to the inlet of the second liquid storage tank, the outlet of the second liquid storage tank is connected to the inlet of the second evaporator, the outlet of the second evaporator is connected to the inlet of the second gas-liquid separator, and the outlet of the second gas-liquid separator is connected to the inlet of the second compressor unit; The second water valve is connected to the heat exchange medium pipeline of the second water-cooled heat exchanger.

[0011] Preferably, the second compressor unit includes a plurality of fixed-frequency compressors.

[0012] Preferably, the condensation reheating section includes a third compressor unit, a third water-cooled heat exchanger, a third liquid storage tank, a third evaporator, a third gas-liquid separator, and a reheater; wherein, The outlet of the third compressor unit is connected to the refrigerant pipeline inlet of the third water-cooled heat exchanger, the refrigerant pipeline outlet of the third water-cooled heat exchanger is connected to the inlet of the third liquid storage tank, the outlet of the third liquid storage tank is connected to the inlet of the third evaporator, the outlet of the third evaporator is connected to the inlet of the third gas-liquid separator, and the outlet of the third gas-liquid separator is connected to the inlet of the third compressor unit; The inlet of the reheater is connected to the outlet of the third compressor unit, and the outlet of the reheater is connected to the inlet of the third evaporator; the reheater is arranged in the downstream direction of the third evaporator; The third water valve is connected to the heat exchange medium pipeline of the third water-cooled heat exchanger.

[0013] Preferably, the third compressor unit includes one or more variable-frequency compressors.

[0014] According to the second aspect of the embodiments of the present invention, a control method for the above water-cooled deep dehumidification air conditioner is provided, including the following steps: Step S1: Start the air supply fan to the preset power of the fan. The controller real-time collects and calculates the target moisture content dob, the incoming air moisture content den, the supply air moisture content dex, the target air temperature tob, the incoming air temperature ten, the supply air temperature tex, the target temperature difference △Tob, the incoming water temperature Ten, the outgoing water temperature Tex, and the temperature difference between the incoming and outgoing water △Twa of each refrigeration section; and judge that when den < dob and ten < tob, go to step S7; when den = dob and ten = tob, repeat step S1; otherwise, enter step S2; Step S2: When dob < den ≤ d1, start the third compressor unit to the initial frequency and open the third water valve; when d1 < den ≤ d2, start the third compressor unit to the initial frequency, start one compressor of the second compressor unit, and open the second water valve and the third water valve; when d2 < den ≤ d3, start the third compressor unit to the initial frequency, start all compressors of the second compressor unit, and open the second water valve and the third water valve; when d3 < den, start the third compressor unit to the initial frequency, start all compressors of the second compressor unit, start the first compressor unit, and open the first water valve, the second water valve and the third water valve; When opening each water valve as described above, when Ten ≤ T1 in the refrigeration section where the water valve is located, the initial opening of the water valve is OP1; when T1 < Ten ≤ T2, the initial opening of the water valve is OP2; when T2 < Ten ≤ T3, the initial opening of the water valve is OP3; when T3 < Ten, the initial opening of the water valve is OP4; Step S3: According to the moisture content read and calculated in real time, judge that when dex = dob, keep the operating frequency of the third compressor unit unchanged; when dex < dob, the third compressor unit reduces the operating frequency according to the humidification design value; when dob < dex, the third compressor unit increases the operating frequency according to the dehumidification design value; Step S4: Obtain the high-pressure pressure HP in real time; when P1 < HP < P2, keep the opening of the third water valve unchanged; when P2 ≤ HP, the third water valve increases the opening according to the increased flow design value to increase the water volume and thus increase the heat exchange amount; when HP ≤ P1, the third water valve reduces the opening according to the decreased flow design value to reduce the water volume and thus reduce the heat exchange amount; Step S5: Obtain the opening OPex of the reheating expansion valve in real time; when tex = tob, keep the opening of the reheating expansion valve unchanged; when tex < tob, the reheating expansion valve increases the opening according to the temperature increase design value; when tob < tex, the reheating expansion valve reduces the opening according to the temperature decrease design value; when OPex ≤ OP5, close the reheating valve; when OP5 < OPex, open the reheating valve; Step S6: For the first refrigeration section and / or the second refrigeration section that have been started, when △Twa = △Tob in this refrigeration section, keep the opening of the first water valve and / or the second water valve unchanged; when △Twa < △Tob, the first water valve and / or the second water valve reduce the opening according to the increased temperature difference design value to reduce the flow rate through the water valve; when △Tob < △Twa, the first water valve and / or the second water valve increase the opening according to the decreased temperature difference design value to increase the flow rate through the water valve; The unstarted refrigeration sections remain unchanged; Step S7: When tex < tob, start the electric heating section to the required power; when dex < dob, start the humidification section to the required humidification amount; go to Step S1.

[0015] Preferably, the step S1 includes the following sub-steps: Sub-step S11: Start the air supply fan 81 to the preset power of the fan; Sub-step S12: The controller collects and calculates the target moisture content dob, the incoming air moisture content den, the supply air moisture content dex, the target air temperature tob, the incoming air temperature ten, the supply air temperature tex, the target temperature difference △Tob, the incoming water temperature Ten, the outgoing water temperature Tex, and the temperature difference between the incoming and outgoing water △Twa of each refrigeration section in real time; Sub-step S13: Compare den with dob, and ten with tob; when den < dob and ten < tob, go to step S7; when den = dob and ten = tob, go to sub-step S12; otherwise, enter step S2.

[0016] Preferably, the step S7 includes the following sub-steps: Sub-step S71: When tex < tob and the reheater expansion valve reaches the maximum opening, enter sub-step S72; when tex < tob and the third compressor unit is not started, enter sub-step S72; otherwise, enter sub-step S73; Sub-step S72: Turn on the electric heating section to the required power; Sub-step S73: When dex < dob and the third compressor unit is not started, turn on the humidification section to the required humidification amount; go back to step S1.

[0017] The present invention makes up for the limitations of traditional air-cooled air conditioners and improves the dehumidification ability and accuracy of the air conditioner. The internal control logic is optimized, making the air conditioner more adaptable and having a higher error tolerance, ensuring the long-term and stable operation of the dehumidification air conditioner. Brief Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a water-cooled deep dehumidification air conditioner in the first embodiment of the present invention; Figure 2 It is Figure 1 the schematic structural diagram of the first-stage refrigeration section in Figure 3 It is Figure 1 the schematic structural diagram of the second-stage refrigeration section in Figure 4 It is Figure 1 the schematic structural diagram of the condensation and reheating section in Figure 5 It is a schematic structural diagram of the water system in the first embodiment of the present invention; Figure 6 It is a schematic diagram of the steps of an adjustment method of a water-cooled deep dehumidification air conditioner in the second embodiment of the present invention; Figure 7 It is Figure 6Schematic diagram of sub-steps of step S1 in Detailed implementation mode

[0019] The technical content of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] The technical concept in the embodiment of the present invention is: using a plate heat exchanger and a water system as the outdoor unit of the air conditioner and the cold source of the outdoor unit to exchange the heat of the air conditioner refrigerant, and sending the heat to the outside by the water system. Specifically, the condensers of each refrigeration section are all water-cooled heat exchangers (such as plate heat exchangers) and exchange heat with the water system. The dehumidification method adopts condensation dehumidification, condensing out moisture by reducing the air temperature, and not directly dehumidifying with cold water. Determine which stage of the refrigeration section to start according to the moisture content of the incoming air temperature, so as to achieve the purpose of deep dehumidification.

[0021] The first embodiment As Figure 1 shown, the embodiment of the present invention provides a water-cooled deep dehumidification air conditioner, which includes an air inlet section 1, a filtration section 2, a first-stage refrigeration section 3, a second-stage refrigeration section 4, a condensation reheating section 5, an electric heating section 6, a humidification section 7, a blower section 8 and a water system 9. The air inlet section 1, the filtration section 2, the first-stage refrigeration section 3, the second-stage refrigeration section 4, the condensation reheating section 5, the electric heating section 6, the humidification section 7 and the blower section 8 are connected in sequence along the air path.

[0022] Among them, the air inlet section 1 is the air inlet section equipment of the water-cooled deep dehumidification air conditioner, including an air duct, an air inlet section temperature sensor 11 and an air inlet section relative humidity sensor 12, which are used to introduce external air and measure the incoming air temperature ten and the incoming air relative humidity Фen. The filtration section 2 is the air filtration section equipment of the water-cooled deep dehumidification air conditioner, which is used to block large particulate matters in the external air. The first-stage refrigeration section 3, the second-stage refrigeration section 4 and the condensation reheating section 5 are collectively referred to as the refrigeration section, and all include independent refrigeration systems. Each refrigeration section adopts a modular design and is independent of each other. The electric heating section 6 is an air heating device, which is used to heat the air flow inside the water-cooled deep dehumidification air conditioner. The humidification section 7 is an air humidification device, which is used to increase the moisture content of the air flow. The blower section 8 is the air supply section equipment, including an air duct, a blower 81, a blower section temperature sensor 82 and a blower section relative humidity sensor 83, which provides the flow power of the air flow to send out the air flow and measures the supply air temperature tex and the supply air relative humidity Фex.

[0023] As Figure 2As shown, the first-stage refrigeration section 3 includes a first compressor unit 31, a first water-cooled heat exchanger 32, a first liquid storage tank 33, a first evaporator 34, and a first gas-liquid separator 35. Among them, the outlet of the first compressor unit 31 is connected to the refrigerant pipeline inlet of the first water-cooled heat exchanger 32, the refrigerant pipeline outlet of the first water-cooled heat exchanger 32 is connected to the inlet of the first liquid storage tank 33, the outlet of the first liquid storage tank 33 is connected to the inlet of the first evaporator 34, the outlet of the first evaporator 34 is connected to the inlet of the first gas-liquid separator 35, and the outlet of the first gas-liquid separator 35 is connected to the inlet of the first compressor unit 31. It should be noted that the first compressor unit 31 is a fixed-frequency compressor.

[0024] After being pressurized and heated by the first compressor unit 31, the refrigerant is input into the refrigerant pipeline of the first water-cooled heat exchanger 32. The first water-cooled heat exchanger 32 includes two independent pipelines (a heat exchange medium pipeline and a refrigerant pipeline) for realizing heat exchange between the fluids in the two pipelines. The heat exchange medium (the heat exchange medium is water in this embodiment) pipeline of the first water-cooled heat exchanger 32 is connected to the water supply pipeline of the water system 9 to reduce the temperature of the refrigerant. The cooled refrigerant is input into the first liquid storage tank 33 for storage along the refrigerant pipeline and, according to the system requirements, is input into the first evaporator 34 to evaporate and absorb heat to reduce the temperature of the air flow in the first-stage refrigeration section 3. The refrigerant that has absorbed heat and increased in temperature is input into the first gas-liquid separator 35, and the gaseous refrigerant therein is input into the first compressor unit 31 to continue circulating.

[0025] As Figure 3 shown, similarly, the second-stage refrigeration section 4 includes a second compressor unit 41, a second water-cooled heat exchanger 42, a second liquid storage tank 43, a second evaporator 44, and a second gas-liquid separator 45. Among them, the outlet of the second compressor unit 41 is connected to the refrigerant pipeline inlet of the second water-cooled heat exchanger 42, the refrigerant pipeline outlet of the second water-cooled heat exchanger 42 is connected to the inlet of the second liquid storage tank 43, the outlet of the second liquid storage tank 43 is connected to the inlet of the second evaporator 44, the outlet of the second evaporator 44 is connected to the inlet of the second gas-liquid separator 45, and the outlet of the second gas-liquid separator 45 is connected to the inlet of the second compressor unit 41. It should be noted that the second compressor unit 41 includes multiple fixed-frequency compressors. For example, it includes two fixed-frequency compressors, and each compressor operates in parallel.

[0026] The second water-cooled heat exchanger 42 includes two independent pipelines (a heat exchange medium pipeline and a refrigerant pipeline) for realizing heat exchange between the fluids in the two pipelines. The heat exchange medium (the heat exchange medium is water in this embodiment) pipeline of the second water-cooled heat exchanger 42 is connected to the water supply pipeline of the water system 9. The refrigerant in the refrigerant pipeline and its working principle are the same as those in the first-stage refrigeration section 3, so they will not be elaborated here.

[0027] As Figure 4As shown in the figure, the condensation and reheating section 5 includes a third compressor unit 51, a third water-cooled heat exchanger 52, a third liquid storage tank 53, a third evaporator 54, a third gas-liquid separator 55, and a reheater 56. Among them, the outlet of the third compressor unit 51 is connected to the refrigerant pipeline inlet of the third water-cooled heat exchanger 52, the refrigerant pipeline outlet of the third water-cooled heat exchanger 52 is connected to the inlet of the third liquid storage tank 53, the outlet of the third liquid storage tank 53 is connected to the inlet of the third evaporator 54, the outlet of the third evaporator 54 is connected to the inlet of the third gas-liquid separator 55, and the outlet of the third gas-liquid separator 55 is connected to the inlet of the third compressor unit 51. The inlet of the reheater 56 is connected to the outlet of the third compressor unit 51, and the outlet is connected to the inlet of the third evaporator 54. The reheater 56 is arranged along the air path in the downstream direction of the third evaporator 54, and the third evaporator 54 is arranged in the upstream direction of the reheater 56. It should be noted that the third compressor unit 51 includes one or more variable-frequency compressors.

[0028] Preferably, the condensation and reheating section 5 further includes a reheating valve 57, a reheating expansion valve 58, and a pressure sensor 59. Among them, the reheating valve 57 is arranged between the third water-cooled heat exchanger 52 and the inlet of the reheater 56, and can conduct or block the connection between the outlet of the third compressor unit 51 and the inlet of the reheater 56. By opening the reheating valve 57, the reheater 56 can be started, so that the high-temperature refrigerant from the third compressor unit 51 flows through the reheater 56 to heat the air flow in the condensation and reheating section 5. By closing the reheating valve 57, the reheater 56 can be closed to lose its heating capacity. The reheating valve 57 is a switch-type on-off valve.

[0029] The reheating expansion valve 58 is arranged between the outlet of the reheater 56 and the inlet of the third evaporator 54, and can adjust or block the flow between the outlet of the reheater 56 and the inlet of the evaporator 54. The reheating expansion valve 58 is an electronic expansion valve.

[0030] The pressure sensor 59 is arranged on the output pipeline of the third compressor unit 51 and is connected to the controller 90 of the water system 9 for measuring the outlet pipeline pressure of the third compressor unit 51. The controller 90 can control the opening degree of the reheating valve 57 through the measured value of the pressure sensor 59.

[0031] The heat exchange medium pipeline of the third water-cooled heat exchanger 52 is connected to the water supply pipeline of the water system 9.

[0032] As Figure 5As shown, the water system 9 includes a controller 90, a water supply pipeline, a water supply device, a first water valve 91, a second water valve 92, a third water valve 93, a first temperature sensor 911, a second temperature sensor 921, and a third temperature sensor 931. Among them, the first water valve 91, the second water valve 92, and the third water valve 93 are collectively referred to as water valves. The first water valve 91 of the water system 9 is connected to the heat exchange medium pipeline of the first water-cooled heat exchanger 32, its second water valve 92 is connected to the heat exchange medium pipeline of the second water-cooled heat exchanger 42, and its third water valve 93 is connected to the heat exchange medium pipeline of the third water-cooled heat exchanger 52. In other words, each refrigeration section is connected to the water system 9 through each water valve and is connected in parallel to the water system 9. The water valve connecting the water system 9 to each refrigeration section is also called the water valve of that refrigeration section. For example, the first water valve 91 is also called the water valve of the first-stage refrigeration section 3. The water system 9 is bidirectionally connected to each refrigeration section, inputs water to each refrigeration section, and receives the return water from each refrigeration section.

[0033] The first temperature sensor 911 is arranged on the first water valve 91 and is used to obtain the inlet water temperature Ten and the outlet water temperature Tex of the first-stage refrigeration section 3 (the first water-cooled heat exchanger 32). The controller 90 calculates the temperature difference △Twa between the inlet and outlet of the first water valve 91, and △Twa = Tex - Ten.

[0034] The second temperature sensor 921 is arranged on the second water valve 92 and is used to obtain the inlet water temperature Ten and the outlet water temperature Tex of the second-stage refrigeration section 4 (the second water-cooled heat exchanger 42). The controller 90 calculates the temperature difference △Twa between the inlet and outlet of the second water valve 92, and △Twa = Tex - Ten.

[0035] The third temperature sensor 931 is arranged on the third water valve 93 and is used to obtain the inlet water temperature Ten and the outlet water temperature Tex of the condensation reheating section 5 (the third water-cooled heat exchanger 52). The controller 90 calculates the temperature difference △Twa between the inlet and outlet of the third water valve 93, and △Twa = Tex - Ten.

[0036] Since the refrigerant heat of each refrigeration section is exchanged to the water system 9 by the water-cooled heat exchanger, △Twa is a positive value.

[0037] It should be noted that for the water-cooled deep dehumidification air conditioner provided in this embodiment, when the third compressor unit 51 is turned on, the third water valve 93 must be turned on. When the second compressor unit 41 is turned on, the second water valve 92 must be turned on. When the first compressor unit 31 is turned on, the first water valve 91 must be turned on. Conversely, for the compressor unit that is not turned on, its corresponding water valve is not turned on either. Turning on the compressor unit means turning on the refrigeration section where the compressor unit is located. In other words, turning on a certain refrigeration section means turning on the compressor unit and the water valve included in that refrigeration section, and turning on a certain compressor unit means turning on that refrigeration section.

[0038] Second Embodiment The second embodiment of the present invention provides a control method for a water-cooled deep dehumidification air conditioner, which controls the start-stop relationship of each refrigeration section and the opening degree of each water valve based on the moisture content of the incoming air of the water-cooled deep dehumidification air conditioner.

[0039] Whether dehumidification is required and the magnitude of the dehumidification intensity are judged by the moisture content. The moisture content refers to the weight of water vapor contained in 1 kg of dry air in moist air, which is called the "moisture content" and is commonly represented by d, unit: g / kg; the enthalpy value is a unit of energy, representing the comprehensive quantity of moisture and temperature contained in a certain volume of air, and is a comprehensive measurement unit of air humidity and humidity magnitude. Its value is completely determined by temperature and humidity, and its calculation formula is as follows: Moisture content calculation formula d = 0.622Фps / (B - Фps) (1) Water vapor saturation partial pressure calculation formula (2) Among them, the moisture content d can be calculated from the relative humidity Ф, the local atmospheric pressure B, and the water vapor saturation partial pressure ps. The water vapor saturation partial pressure ps can be calculated from the temperature t and relevant constants. However, the moisture content d, as a state function, is not related to the temperature t. On the enthalpy-humidity diagram, the moisture content corresponds one-to-one with the thermodynamic state of the air and is suitable as a feedback variable for the control system. In the field of dehumidification air conditioners, the moisture content is a reliable control benchmark due to its temperature independence and direct mathematical relationship with the dehumidification amount.

[0040] The comfortable range of moisture content d is: ① in summer, 5 - 12 g / kg, corresponding to a temperature of 24 - 28 °C and a relative humidity of 40% - 60%; ② in winter, 3 - 6 g / kg, corresponding to a temperature of 18 - 22 °C and a relative humidity of 30% - 50%. At high temperatures, a low moisture content (such as 8 g / kg) is more comfortable. In humid and hot areas (such as mines and tunnels), the moisture content needs to be controlled below 12 g / kg.

[0041] Therefore, the control method provided by the embodiment of the present invention uses the incoming air moisture content den, the target moisture content dob, the supply air moisture content dex, the first moisture content d1, the second moisture content d2, and the third moisture content d3 as control benchmarks. Among them, the incoming air moisture content den is the moisture content of the incoming air of the incoming air section 1, which is calculated by the controller 90 of the water system 9 from the incoming air temperature ten and the incoming air relative humidity Фen of the incoming air section 1. The target moisture content dob is the moisture content of the supply air of the supply fan section 8 set (expected) manually. The supply air moisture content dex is the moisture content of the supply air of the supply fan section 8, which is calculated by the controller 90 of the water system 9 from the supply air temperature tex and the supply air relative humidity Фex of the supply fan section 8. The first moisture content d1, the second moisture content d2, and the third moisture content d3 are reference values set manually.

[0042] In one embodiment of the present invention, dob < d1 < d2 < d3. Optionally, dob is 3 - 12 g / kg, d1 is 10 - 14 g / kg, d2 is 16 - 20 g / kg, and d3 is 23 - 27 g / kg. Preferably, d1 is 12 g / kg, d2 is 18 g / kg, and d3 is 25 g / kg.

[0043] Preferably, in the embodiment of the present invention, the inlet air temperature ten, the target air temperature tob, the supply air temperature tex, the inlet water temperature Ten of each refrigeration section, the outlet water temperature Tex of each refrigeration section, the temperature difference ΔTwa between the inlet and outlet water of each refrigeration section, the target temperature difference ΔTob, the first water temperature T1, the second water temperature T2, and the third water temperature T3 are used as control references. Among them, the inlet air temperature ten is the air temperature of the inlet air in the inlet air section 1, which is obtained by the inlet air section temperature sensor 11. The target air temperature tob is the air temperature of the supply air in the supply fan section 8 set (expected) manually. The supply air temperature tex is the temperature of the supply air in the supply fan section 8, which is obtained by the supply fan section temperature sensor 82. The inlet water temperature Ten of each refrigeration section is the inlet water temperature of the water-cooled heat exchanger in each refrigeration section input by the water system 9, which is obtained by each temperature sensor of the water system 9. The outlet water temperature Tex of each refrigeration section is the outlet water temperature of the water-cooled heat exchanger in each refrigeration section output by the water system 9, which is obtained by each temperature sensor of the water system 9. The temperature difference ΔTwa between the inlet and outlet water of each refrigeration section (water-cooled heat exchanger) = Tex - Ten, which is calculated by the controller 90 of the water system 9. The target temperature difference ΔTob is the temperature difference between the inlet and outlet water set (expected) manually. The first water temperature T1, the second water temperature T2, and the third water temperature T3 are the inlet water temperature reference values set manually.

[0044] In one embodiment of the present invention, T1 < T2 < T3. Optionally, T1 is 10 - 20 °C, T2 is 20 - 30 °C, and T3 is 30 - 40 °C. Preferably, T1 is 15 °C, T2 is 25 °C, and T3 is 35 °C.

[0045] Optionally, ΔTob is 1 - 9 °C. Preferably, ΔTob is 5 °C.

[0046] It should be noted that for the water-cooled deep dehumidification air conditioner provided in the embodiment of the present invention, its special working environment requires a lower air volume and a deep dehumidification function, and it is easy to freeze due to insufficient air flow, resulting in the evaporator being unable to release heat in time. For the control method provided in the embodiment of the present invention, controlling the temperature difference between the inlet and outlet water at 5 °C can keep the refrigerant after the plate heat exchanger at a high degree of subcooling (10 - 15 °C), which can improve the stability of the air conditioning system in a low-temperature environment and reduce the risk of evaporator frosting.

[0047] Preferably, in the embodiment of the present invention, the high-pressure pressure HP, the first pressure P1, and the second pressure P2 are used as control references. Among them, the high-pressure pressure HP is the outlet pipeline pressure of the third compressor unit 51, which is obtained by the pressure sensor 59. The first pressure P1 and the second pressure P2 are artificially set high-pressure pressure reference values. Among them, P1 < P2. Optionally, P1 is 1 - 2 MPa, and P2 is 2 - 3 MPa. Preferably, P1 is 1.5 MPa, and P2 is 2.2 MPa.

[0048] Preferably, in the embodiment of the present invention, the expansion valve opening OPex is used as the control reference to control the on-off of the reheating valve 57. Among them, OPex is the opening of the reheating expansion valve 58, which is controlled by the inlet air temperature ten and the supply air temperature tex. It should be noted that the control methods of the third compressor unit 51, the reheater 56, and the reheating expansion valve 58 in the condensation reheating air conditioner are prior arts, and reference can be made to the inventor's prior invention patent CN118640592B, which will not be elaborated here.

[0049] In the embodiment of the present invention, adjusting the openings of the first water valve 91, the second water valve 92, the third water valve 93, the reheating valve 57, and the reheating expansion valve 58, as well as the working states of the first compressor unit 31, the second compressor unit 41, the third compressor unit 51, the electric heating section 6, and the humidifying section 7 are used as control means. Among them, the first opening OP1, the second opening OP2, the third opening OP3, the fourth opening OP4, and the fifth opening OP5 are artificially set as reference values. The opening is the maximum flow percentage of the valve.

[0050] In an embodiment of the present invention, OP1 < OP2 < OP3 < OP4. Optionally, OP1 is 0 - 20%, OP2 is 20% - 40%, OP3 is 40% - 60%, and OP4 is 60% - 80%. Preferably, OP1 is 10%, OP2 is 30%, OP3 is 50%, and OP4 is 70%. OP5 is an independent reference applied to the reheating expansion valve 58.

[0051] As Figure 6 shown, the embodiment of the present invention provides a control method for a water-cooled deep dehumidification air conditioner, including the following steps.

[0052] Step S1: Start the supply air fan 81 to the preset power of the fan, and the controller 90 collects and calculates the target moisture content dob, the inlet air moisture content den, the supply air moisture content dex, the target air temperature tob, the inlet air temperature ten, the supply air temperature tex, the target temperature difference △Tob, the inlet water temperature Ten, the outlet water temperature Tex, and the inlet and outlet water temperature difference △Twa of each refrigeration section in real time; and judge that when den < dob and ten < tob, go to step S7; when den = dob and ten = tob, repeat step S1; otherwise, enter step S2.

[0053] When den < dob and ten < tob, it indicates that the incoming air does not need to be cooled, dehumidified, so it directly enters step S7 for heating and humidifying. When den = dob and ten = tob, it indicates that the temperature and humidity of the incoming air meet the expectations and do not need to be processed, so step S1 is repeated.

[0054] As Figure 7 shown, preferably, this step includes the following sub-steps: Sub-step S11: Start the air supply fan 81 to the preset power of the fan.

[0055] Starting the air supply fan will cause the air flow inside the water-cooled deep dehumidification air conditioner.

[0056] Sub-step S12: The controller 90 collects and calculates the target moisture content dob, the incoming air moisture content den, the supply air moisture content dex, the target air temperature tob, the incoming air temperature ten, the supply air temperature tex, the target temperature difference △Tob, the inlet water temperature Ten, the outlet water temperature Tex and the inlet and outlet water temperature difference △Twa of each refrigeration section in real time.

[0057] Sub-step S13: Compare den with dob and ten with tob; when den < dob and ten < tob, go to step S7; when den = dob and ten = tob, go to sub-step S12; otherwise, enter step S2.

[0058] Step S2: When dob < den ≤ d1, start the third compressor unit to the initial frequency (for example, 30Hz) and open the third water valve 93; when d1 < den ≤ d2, start the third compressor unit 51 to the initial frequency, start one compressor of the second compressor unit 41, and open the second water valve 92 and the third water valve 93; when d2 < den ≤ d3, start the third compressor unit 51 to the initial frequency, start all the compressors of the second compressor unit 41, and open the second water valve 92 and the third water valve 93; when d3 < den, start the third compressor unit 51 to the initial frequency, start all the compressors of the second compressor unit 41, start the first compressor unit 31, and open the first water valve 91, the second water valve 92 and the third water valve 93.

[0059] For the water-cooled deep dehumidification air conditioner provided by the present invention, dehumidification mainly relies on the condensation and reheating section 5 for condensation dehumidification, so as long as there is a dehumidification requirement (dob < den), the condensation and reheating section 5 is started. According to the different required cooling capacities, the second-stage refrigeration section 4 and the first-stage refrigeration section 3 are started in sequence as the precooling refrigeration sections of the condensation and reheating section 5. In this way, the start and stop of the second-stage refrigeration section 4 and the first-stage refrigeration section 3 can be controlled according to the real-time collected humidity, thereby saving energy consumption.

[0060] When opening each water valve as described above, when Ten ≤ T1 in the refrigeration section where the water valve is located, the initial opening degree of the water valve is OP1; when T1 < Ten ≤ T2, the initial opening degree of the water valve is OP2; when T2 < Ten ≤ T3, the initial opening degree of the water valve is OP3; when T3 < Ten, the initial opening degree of the water valve is OP4.

[0061] The water valves in the unopened refrigeration sections remain closed.

[0062] Step S3: According to the moisture content read and calculated in real time, it is judged that when dex = dob, the operating frequency of the third compressor unit remains unchanged; when dex < dob, the third compressor unit 51 reduces the operating frequency according to the humidification design value; when dob < dex, the third compressor unit 51 increases the operating frequency according to the dehumidification design value.

[0063] Step S4: Obtain the high-pressure pressure HP in real time; when P1 < HP < P2, the opening degree of the third water valve 93 remains unchanged; when P2 ≤ HP, the third water valve 93 increases the opening degree according to the increased flow design value to increase the water volume, and thus increase the heat exchange amount; when HP ≤ P1, the third water valve 93 reduces the opening degree according to the decreased flow design value to reduce the water volume, and thus reduce the heat exchange amount.

[0064] Controlling the opening degree of the third water valve 93 based on the pressure of the pressure sensor 59 in the condensation reheating section 5 can take into account the different heat exchange requirements of the refrigerant in the on and off states of the reheater 56.

[0065] For example, in the case where the reheater 56 (reheat valve 57) is not opened, the refrigerant in the condensation reheating section 5 is cooled by heat exchange with the third water-cooled heat exchanger 52. When the opening degree of the third water valve 93 is large, the water flow rate of the third water-cooled heat exchanger 52 is large. Therefore, the temperature of the refrigerant after heat exchange is low, which is manifested as a low outlet pressure (HP) of the third compressor unit 51. At this time, the opening degree of the third water valve 93 can be reduced to maintain the refrigerant temperature within the design range while saving water volume.

[0066] When the opening degree of the third water valve 93 is small, the water flow rate of the third water-cooled heat exchanger 52 is small. Therefore, the temperature of the refrigerant after heat exchange is high, which is manifested as a high outlet pressure (HP) of the third compressor unit 51. At this time, the opening degree of the third water valve 93 can be increased to maintain the refrigerant temperature within the design range while increasing the water volume.

[0067] In the case where the reheater 56 (reheat valve 57) is opened, a part of the refrigerant is shunted into the reheater 56 for heat exchange, increasing the heat exchange area and heat exchange effect of the refrigerant, and the refrigerant temperature decreases, which is manifested as a decrease in the outlet pressure (HP) of the third compressor unit 51. At this time, the opening degree of the third water valve 93 can be reduced to maintain the refrigerant temperature within the design range while saving water volume.

[0068] It should be noted that the third pressure sensor 59 is also an auxiliary device of the third compressor unit 51, used to detect the outlet pressure of the third compressor unit 51 to adjust the operating frequency and perform pressure protection. In the embodiment of the present invention, the high-pressure pressure HP is used as the control reference for the opening of the third water valve 93, without the need to add a sensor dedicated to controlling the third water valve 93, and it also better meets the requirements of the condensation reheating section 5.

[0069] Step S5: Obtain the opening OPex of the reheating expansion valve 58 in real time; when tex = tob, keep the opening of the reheating expansion valve 58 unchanged; when tex < tob, increase the opening of the reheating expansion valve 58 according to the designed value for temperature rise; when tob < tex, decrease the opening of the reheating expansion valve 58 according to the designed value for temperature drop; when OPex ≤ OP5, close the reheating valve; when OP5 < OPex, open the reheating valve.

[0070] Due to the existence of the reheater 56 and its branch pipelines, even if the reheating valve 57 is closed, a small amount of refrigerant will leak into the reheater 56. Therefore, the reheating expansion valve 58 needs to maintain a small step opening (basically no opening) to make the refrigerant leaking into the reheater 56 flow back to the compressor, avoiding refrigerant imbalance and affecting the refrigeration capacity of the system. Therefore, the on-off of the reheating valve 57 is controlled based on the opening of the reheating expansion valve 58.

[0071] Step S6: For the already opened first refrigeration section 3 and / or second refrigeration section 4, when the △Twa of this refrigeration section = △Tob, keep the opening of the first water valve 91 and / or second water valve 92 unchanged; when △Twa < △Tob, decrease the opening of the first water valve 91 and / or second water valve 92 according to the designed value for increasing temperature difference to reduce the flow rate through the water valve; when △Tob < △Twa, increase the opening of the first water valve and / or second water valve according to the designed value for decreasing temperature difference to increase the flow rate through the water valve.

[0072] The unopened refrigeration section remains unchanged.

[0073] Step S7: When tex < tob, turn on the electric heating section to the required power; when dex < dob, turn on the humidification section to the required humidification amount; go to step S1.

[0074] The main purpose of this step is to provide heating and humidification functions to meet the operating conditions that only require heating and humidifying the incoming air. The secondary purpose is to make up for the insufficient heating capacity of the reheater 56 and continue to increase the supply air temperature with the electric heating section 6. Therefore, this step also includes the following sub-steps: Sub-step S71: When tex < tob and the reheating expansion valve reaches the maximum opening, enter sub-step S72; when tex < tob and the third compressor unit is not turned on, enter sub-step S72; otherwise enter sub-step S73.

[0075] When tex < tob and the reheater expansion valve reaches its maximum opening, it indicates that the heating capacity of only the reheater 56 is no longer sufficient to raise the supply air temperature tex to the target air temperature tob, and thus the electric heating section 6 needs to be turned on to supplement heat.

[0076] When tex < tob and the third compressor unit 51 is not turned on, it indicates that the condensation and dehumidification function is not activated in this operating condition, and only the electric heating section 6 needs to be turned on to increase the supply air temperature tex.

[0077] When tex < tob and the reheater expansion valve does not reach its maximum opening, it indicates that the heating function of the reheater 56 is activated in this operating condition, and there is still room for its heating capacity to continue to increase, and there is no need for the electric heating section 6 to increase the supply air temperature tex.

[0078] It should be noted that there are various control methods to start the electric heating section 6 when the opening of the reheater expansion valve 58 reaches its maximum, such as controlling the start and stop of the electric heating section 6 through the opening of the reheater expansion valve 58, or by setting different sensor acquisition frequencies, which will not be elaborated here.

[0079] Sub-step S72: Turn on the electric heating section to the required power.

[0080] Sub-step S73: When dex < dob and the third compressor unit is not turned on, turn on the humidifying section to the required humidification amount; go to step S1.

[0081] It should be noted that the order of steps S3 to S6 provided in the embodiments of the present invention can be changed according to actual needs, the sequence between the steps can also be changed, and serial processing can also be changed to parallel processing, which is not limited to the step sequence listed in the embodiments. When the supply air fan is not started, the first water valve 91, the second water valve 92, the third water valve 93 and the reheater valve 57 provided in the embodiments of the present invention are all in the closed (blocked) state, and the first compressor unit 31, the second compressor unit 41 and the third compressor unit 51 are all in the shutdown state.

[0082] The control methods for each refrigeration section are described separately below.

[0083] For the condensation and reheating section 5: When dob < den, start the third compressor unit 51 to the design frequency; when Ten of the condensation and reheating section 5 ≤ T1, the initial opening of the third water valve 93 is OP1; when T1 < Ten ≤ T2, the initial opening of the third water valve 93 is OP2; when T2 < Ten ≤ T3, the initial opening of the third water valve 93 is OP3; when T3 < Ten, the initial opening of the third water valve 93 is OP4; When dex = dob, maintain the operating frequency of the third compressor unit unchanged; when dex < dob, the third compressor unit reduces its operating frequency; when dob < dex, the third compressor unit increases its operating frequency; When P1 < HP < P2, keep the opening degree of the third water valve unchanged; when P2 ≤ HP, increase the opening degree of the third water valve; when HP ≤ P1, decrease the opening degree of the third water valve; When tex = tob, keep the opening degree of the reheating expansion valve unchanged; when tex < tob, increase the opening degree of the reheating expansion valve according to the design value; when tob < tex, decrease the opening degree of the reheating expansion valve according to the design value; when OPex ≤ OP5, close the reheating valve; when OP5 < OPex, open the reheating valve.

[0084] For the second refrigeration section 4: when d1 < den ≤ d2, turn on one compressor of the second compressor unit; when d2 < den ≤ d3, turn on all compressors of the second compressor unit; when Ten ≤ T1 in the second refrigeration section 4, the initial opening degree of the second water valve 92 is OP1; when T1 < Ten ≤ T2, the initial opening degree of the second water valve 92 is OP2; when T2 < Ten ≤ T3, the initial opening degree of the second water valve 92 is OP3; when T3 < Ten, the initial opening degree of the second water valve 92 is OP4; When △Twa = △Tob in the second refrigeration section 4, keep the opening degree of the second water valve 92 unchanged; when △Twa < △Tob, decrease the opening degree of the second water valve 92; when △Tob < △Twa, increase the opening degree of the second water valve 92.

[0085] For the first refrigeration section 3: when d3 < den, turn on the first compressor unit; when Ten ≤ T1 in the first refrigeration section 3, the initial opening degree of the first water valve 91 is OP1; when T1 < Ten ≤ T2, the initial opening degree of the first water valve 91 is OP2; when T2 < Ten ≤ T3, the initial opening degree of the first water valve 91 is OP3; when T3 < Ten, the initial opening degree of the first water valve 91 is OP4; When △Twa = △Tob in the first refrigeration section 3, keep the opening degree of the first water valve 91 unchanged; when △Twa < △Tob, decrease the opening degree of the first water valve 91; when △Tob < △Twa, increase the opening degree of the first water valve 91.

[0086] When the present invention starts, taking the moisture content as the judgment criterion, it judges which level of refrigeration to turn on according to the moisture content of the incoming air; after operation, the water system regulation of the first and second levels of refrigeration is controlled according to the temperature difference between the incoming and return water, so that the temperature difference is controlled at about 5°C. The water system regulation of the third level of refrigeration is to control the opening degree of the water valve by taking the high-pressure pressure of the third-level compressor as the judgment criterion; finally, the dehumidification heat compensation function is based on the opening degree of the electronic expansion valve as the judgment criterion to ensure that the outgoing air temperature and humidity are maintained near the target values.

[0087] Generally, the underground space is far from the ground open space. If a compressor and an air-cooled radiator are set in the ground open space and high-pressure refrigerant is transported to the underground space for refrigeration and heat exchange, long-distance pressure-maintaining and heat-insulating pipelines need to be set, so the cost is high and the refrigeration efficiency is poor (there is cold loss along the way). In the prior art, a refrigeration station is mostly set in the open space (ground) and chilled water is transported to the narrow space (tunnel working face) for refrigeration and heat exchange. Although the chilled water pipeline is an atmospheric pressure pipeline, heat-insulating measures still need to be set. The water-cooled deep dehumidification air conditioner provided by the embodiment of the present invention sets the compressor in the underground space, uses normal-temperature water and a plate heat exchanger as the cold source, and the water system pipeline is an atmospheric pressure pipeline and does not need heat insulation, so the cost is low and the refrigeration efficiency is high. At the same time, in the water system of the embodiment of the present invention, if the normal-temperature water is taken from the underground water inflow, the water system pipeline can be further simplified and the load of discharging the water inflow can be shared.

[0088] After calculation, to achieve the same heat exchange capacity, the heat exchange area of the plate heat exchanger required in the present invention (water-cooled system) is 25% - 27% of the heat exchange area of the condenser in the traditional air-cooled system. Therefore, the required space is small, saving the precious space of underground engineering. Moreover, the energy efficiency ratio COP of the present invention is 4.5 - 5.0, and the energy efficiency ratio COP of the traditional air-cooled system is 3.0 - 3.5, which significantly saves energy consumption. Generally speaking, under the same heat exchange capacity, the dehumidification capacity of the present invention is 1.42 - 1.5 times that of the traditional air-cooled system, having remarkable economic benefits.

[0089] Moreover, the present invention solves the problem that it is difficult for the traditional air-cooled system to maintain the outlet air at around 7°C. Because it is difficult for the traditional air-cooled system to maintain the evaporator temperature at 3 - 5°C for a long time and the evaporator is prone to freezing. If this problem is to be solved, on the one hand, a super-large air-cooled heat exchange system is required, and the cost will increase several times to timely take away the cold of the evaporator and avoid the evaporator from icing, which is not economical. On the other hand, the increase in air volume means that the outlet air temperature cannot be maintained at a low temperature and cannot reach the target temperature requirement. Therefore, the traditional air-cooled system cannot meet the requirements of dehumidification and low-temperature outlet air in special occasions (such as underground engineering).

[0090] In summary, a water-cooled deep dehumidification air conditioner and its control method provided by the embodiment of the present invention realize the deep dehumidification function through an optimized refrigeration cycle system, an efficient evaporator and a water-cooled condenser, can reduce the indoor humidity to a lower level and keep it stable, and meet the requirements of places with strict humidity requirements. The intelligent control system accurately adjusts the operating states of each component of the air conditioner according to the humidity and temperature data monitored in real time, not only improves the accuracy of dehumidification and temperature control, but also realizes energy-saving operation, reducing energy consumption and operating costs.

[0091] It should be noted that the above-mentioned multiple embodiments are only examples. The technical solutions of each embodiment can be combined, and all are within the protection scope of the present invention.

[0092] It should be noted that the step sequence of the present invention can be changed according to actual needs. The sequence order between steps can be changed, and serial processing can also be changed to parallel processing, which is not limited to the step sequence listed in the embodiments.

[0093] The orientation or positional relationship indicated by terms such as "depth", "upper", "lower", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0094] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0095] The above has made a detailed description of a water-cooled deep dehumidification air conditioner and its control method provided by the present invention. For those of ordinary skill in the art, any obvious changes made without departing from the substantial content of the present invention will constitute an infringement of the patent right of the present invention and shall bear corresponding legal responsibilities.

Claims

1. A water-cooled deep dehumidification air conditioner, characterized in that It includes an air inlet section, a filtration section, a first-stage refrigeration section, a second-stage refrigeration section, a condensation and reheating section, an electric heating section, a humidification section, a blower section and a water system. Among them, the air inlet section, the filtration section, the first-stage refrigeration section, the second-stage refrigeration section, the condensation and reheating section, the electric heating section, the humidification section and the blower section are sequentially connected along the air path; the first-stage refrigeration section, the second-stage refrigeration section and the condensation and reheating section all include independent refrigeration systems; the water system includes a controller, a first water valve, a second water valve, a third water valve, a first temperature sensor, a second temperature sensor and a third temperature sensor; the water system is connected to the first-stage refrigeration section through the first water valve, and the first temperature sensor obtains the inlet and outlet water temperatures of the first-stage refrigeration section; the water system is connected to the second-stage refrigeration section through the second water valve, and the second temperature sensor obtains the inlet and outlet water temperatures of the second-stage refrigeration section; the water system is connected to the condensation and reheating section through the third water valve, and the third temperature sensor obtains the inlet and outlet water temperatures of the condensation and reheating section.

2. The water-cooled deep dehumidification air conditioner according to claim 1, wherein: the air inlet section is an air inlet device, including an air inlet section temperature sensor and an air inlet section relative humidity sensor, used to introduce external air and measure the inlet air temperature and inlet air relative humidity; the filtration section is an air filtration device; the electric heating section is an air heating device; the humidification section is an air humidification device; the blower section is a blowing device, including a blowing fan, a blowing section temperature sensor and a blowing section relative humidity sensor, used to blow air and measure the blowing temperature and blowing relative humidity.

3. The water-cooled deep dehumidification air conditioner according to claim 1, characterized in that The first-stage refrigeration section includes a first compressor unit, a first water-cooled heat exchanger, a first liquid storage tank, a first evaporator and a first gas-liquid separator; among them, the outlet of the first compressor unit is connected to the refrigerant pipeline inlet of the first water-cooled heat exchanger, the refrigerant pipeline outlet of the first water-cooled heat exchanger is connected to the inlet of the first liquid storage tank, the outlet of the first liquid storage tank is connected to the inlet of the first evaporator, the outlet of the first evaporator is connected to the inlet of the first gas-liquid separator, and the outlet of the first gas-liquid separator is connected to the inlet of the first compressor unit; the first water valve is connected to the heat exchange medium pipeline of the first water-cooled heat exchanger.

4. The water-cooled deep dehumidification air conditioner according to claim 1, wherein The second-stage refrigeration section includes a second compressor unit, a second water-cooled heat exchanger, a second liquid storage tank, a second evaporator and a second gas-liquid separator; among them, the outlet of the second compressor unit is connected to the refrigerant pipeline inlet of the second water-cooled heat exchanger, the refrigerant pipeline outlet of the second water-cooled heat exchanger is connected to the inlet of the second liquid storage tank, the outlet of the second liquid storage tank is connected to the inlet of the second evaporator, the outlet of the second evaporator is connected to the inlet of the second gas-liquid separator, and the outlet of the second gas-liquid separator is connected to the inlet of the second compressor unit; the second water valve is connected to the heat exchange medium pipeline of the second water-cooled heat exchanger.

5. The water-cooled deep dehumidification air conditioner according to claim 4, wherein: the second compressor unit includes a plurality of constant-frequency compressors.

6. The water-cooled deep dehumidification air conditioner according to claim 1, wherein The condensation and reheating section includes a third compressor unit, a third water-cooled heat exchanger, a third liquid storage tank, a third evaporator, a third gas-liquid separator, and a reheater; wherein, The outlet of the third compressor unit is connected to the refrigerant pipeline inlet of the third water-cooled heat exchanger, the refrigerant pipeline outlet of the third water-cooled heat exchanger is connected to the inlet of the third liquid storage tank, the outlet of the third liquid storage tank is connected to the inlet of the third evaporator, the outlet of the third evaporator is connected to the inlet of the third gas-liquid separator, and the outlet of the third gas-liquid separator is connected to the inlet of the third compressor unit; The inlet of the reheater is connected to the outlet of the third compressor unit, and the outlet of the reheater is connected to the inlet of the third evaporator; the reheater is arranged in the downstream direction of the third evaporator; The third water valve is connected to the heat exchange medium pipeline of the third water-cooled heat exchanger.

7. The water-cooled deep dehumidification air conditioner according to claim 6, wherein: The third compressor unit includes one or more variable frequency compressors.

8. A control method for a water-cooled deep dehumidification air conditioner, implemented based on the water-cooled deep dehumidification air conditioner according to any one of claims 1 to 7, characterized in that It includes the following steps: Step S1: Start the supply air fan to the preset power of the fan. The controller real-time collects and calculates the target moisture content dob, the incoming air moisture content den, the supply air moisture content dex, the target air temperature tob, the incoming air temperature ten, the supply air temperature tex, the target temperature difference △Tob, the inlet water temperature Ten and the outlet water temperature Tex of each refrigeration section, and the temperature difference △Twa between the inlet and outlet water; and judge that when den < dob and ten < tob, go to step S7; When den = dob and ten = tob, repeat step S1; otherwise , enter step S2; Step S2: When dob < den ≤ d1, start the third compressor unit to the initial frequency and open the third water valve; When d1 < den ≤ d2, start the third compressor unit to the initial frequency, start one compressor of the second compressor unit, and open the second water valve and the third water valve; When d2 < den ≤ d3, start the third compressor unit to the initial frequency, start all the compressors of the second compressor unit, and open the second water valve and the third water valve; When d3 < den, start the third compressor unit to the initial frequency, start all the compressors of the second compressor unit, start the first compressor unit, and open the first water valve, the second water valve and the third water valve; When opening each water valve as mentioned above, when Ten ≤ T1 in the refrigeration section where the water valve is located, the initial opening of the water valve is OP1; When T1 < Ten ≤ T2, the initial opening of the water valve is OP2; when T2 < Ten ≤ T3, the initial opening of the water valve is OP3; when T3 < Ten, the initial opening of the water valve is OP4; Step S3: According to the moisture content read and calculated in real time, judge that when dex = dob, keep the operating frequency of the third compressor unit unchanged; When dex < dob, the third compressor unit reduces the operating frequency according to the humidification design value; when dob < dex, the third compressor unit increases the operating frequency according to the dehumidification design value; Step S4: Obtain the high-pressure pressure HP in real time; when P1 < HP < P2, keep the opening degree of the third water valve unchanged; when P2 ≤ HP, increase the opening degree of the third water valve according to the designed increased flow rate to increase the water volume and thus increase the heat exchange amount; when HP ≤ P1, decrease the opening degree of the third water valve according to the designed decreased flow rate to reduce the water volume and thus reduce the heat exchange amount; Step S5: Obtain the opening degree OPex of the reheating expansion valve in real time; when tex = tob, keep the opening degree of the reheating expansion valve unchanged; when tex < tob, increase the opening degree of the reheating expansion valve according to the designed temperature increase value; when tob < tex, decrease the opening degree of the reheating expansion valve according to the designed temperature decrease value; when OPex ≤ OP5, close the reheating valve; when OP5 < OPex, open the reheating valve; Step S6: For the first refrigeration section and / or the second refrigeration section that have been opened, when the △Twa of this refrigeration section = △Tob, keep the opening degree of the first water valve and / or the second water valve unchanged; when △Twa < △Tob, decrease the opening degree of the first water valve and / or the second water valve according to the designed increased temperature difference value to reduce the flow rate through the water valve; when △Tob < △Twa, increase the opening degree of the first water valve and / or the second water valve according to the designed decreased temperature difference value to increase the flow rate through the water valve; The unopened refrigeration sections remain unchanged; Step S7: When tex < tob, turn on the electric heating section to the required power; when dex < dob, turn on the humidification section to the required humidification amount; go to Step S1.

9. The control method of the water-cooled deep dehumidification air conditioner according to claim 8, characterized in that The said Step S1 includes the following sub-steps: Sub-step S11: Start the air supply fan 81 to the preset power of the fan; Sub-step S12: The controller collects and calculates in real time the target moisture content dob, the incoming air moisture content den, the supply air moisture content dex, the target air temperature tob, the incoming air temperature ten, the supply air temperature tex, the target temperature difference △Tob, the incoming water temperature Ten, the outgoing water temperature Tex and the temperature difference △Twa of each refrigeration section; Sub-step S13: Compare den with dob, and ten with tob; when den < dob and ten < tob, go to Step S7; when den = dob and ten = tob, go to Sub-step S12; Otherwise, enter Step S2.

10. The control method of the water-cooled deep dehumidification air conditioner according to claim 8, characterized in that The said Step S7 includes the following sub-steps: Sub-step S71: When tex < tob and the reheating expansion valve reaches the maximum opening degree, enter Sub-step S72; when tex < tob and the third compressor unit is not started, enter Sub-step S72; otherwise enter Sub-step S73; Sub-step S72: Turn on the electric heating section to the required power; Sub-step S73: When dex < dob and the third compressor unit is not started, then turn on the humidification section to the required humidification amount; go to Step S1.

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