Dual cold source low dew point closed water cooling double-effect heat recovery unit and control method

Abstract

This invention discloses a dual-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit and its control method. The unit includes: a main circuit, a first heat exchanger, a first three-way valve, a second three-way valve, a humidifier, a control module, and a second heat exchanger. The main circuit includes a compressor, a four-way valve, a water-cooled heat exchanger, a throttling structure, and an evaporator connected in sequence. The control module determines the operating mode based on environmental information and regulates the main circuit, the humidifier, the first three-way valve, the second three-way valve, the first heat exchanger, and the second heat exchanger. Utilizing externally input chilled water, the system adjusts the temperature of the air output from the third chamber at the air outlet while simultaneously adjusting the return temperature of the chilled water and outputting treated chilled water back to the outside. This satisfies the varying indoor heat load requirements due to different air supply temperature differences, achieving double-effect heat recovery and solving the problem of high energy consumption and large electric reheat requirements in dual-source, low-dew-point applications, making the unit more efficient, stable, and simple.

Description

Technical Field

[0001] This invention relates to the field of air conditioning equipment technology, and in particular to a dual-source, low-dew-point, closed-loop water-cooled dual-effect heat recovery unit and its control method. Background Technology

[0002] Today, air conditioning systems face increasingly stringent requirements for cleanliness and temperature / humidity, leading to a significant increase in energy consumption. Therefore, high efficiency and energy conservation have become key concerns. Dual-source air conditioning has existed for some time, but its widespread adoption is limited. Current technologies often utilize dual-source technology to address the insufficient dehumidification capacity of a single cold source or to improve system energy efficiency by using different grades of cold sources. However, this approach often results in complex on-site piping networks, limited equipment space, and cumbersome operation and maintenance, hindering the widespread application of dual-source technology.

[0003] Therefore, based on this situation and the background of dual carbon, there is an urgent need for a dual-source cooling unit that meets the major premise of low dew point and frost-free dehumidification, can improve energy efficiency and simplify operation and maintenance management. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-source, low-dew-point, closed-loop water-cooled dual-effect heat recovery unit and its control method to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0005] The solution to the technical problem of this invention is to provide a dual-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit and its control method.

[0006] According to an embodiment of a first aspect of the present invention, a dual-source low-dew-point closed-loop water-cooled dual-effect heat recovery unit is provided, comprising: a housing, a main circuit, a first heat exchanger, a first three-way valve, a second three-way valve, a humidifier, a control module, and a second heat exchanger;

[0007] The main circuit includes a compressor, a four-way valve, a water-cooled heat exchanger, a throttling structure, and an evaporator connected in sequence. The control module determines the operating mode based on environmental information and regulates the main circuit, humidifier, first three-way valve, second three-way valve, first heat exchanger, and second heat exchanger. The environmental information includes fresh air temperature, wall temperature, dew point temperature, internal temperature, and / or supply air temperature. The operating modes include dehumidification mode and humidification mode.

[0008] The first heat exchanger is used to perform heat exchange treatment on externally input chilled water and fresh air to obtain first chilled water and first chamber air. The first three-way valve is used to divide the first chilled water into second chilled water and third chilled water, and to mix the third chilled water and fourth chilled water to form fifth chilled water. The water-cooled heat exchanger is used to perform heat exchange treatment on the second chilled water to obtain fourth chilled water. The evaporator is used to perform heat exchange treatment on the first chamber air to obtain second chamber air.

[0009] When the operating mode is dehumidification mode, the second three-way valve divides the fifth chilled water into the sixth chilled water and the seventh chilled water, mixes the seventh chilled water and the eighth chilled water to form the ninth chilled water and outputs it, and the second heat exchanger is used to perform heat exchange treatment on the sixth chilled water and the air inside the second chamber to obtain the eighth chilled water and the output air inside the third chamber.

[0010] When the operating mode is humidification mode, the second three-way valve outputs the fifth chilled water, and the humidifier is used to humidify the air in the second chamber to obtain the output air in the third chamber.

[0011] Furthermore, a dual-source low-dew-point closed-loop water-cooled dual-effect heat recovery unit also includes: a two-way flow valve;

[0012] The two-way flow valve is located outside the casing and is connected to the second three-way valve through the second heat exchanger.

[0013] Furthermore, a dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit also includes: a dew point detector, a temperature detector, and a wall temperature detector;

[0014] The dew point detector is used to obtain the dew point temperature, the temperature detector is used to obtain the temperature inside the chamber, and the wall temperature detector is used to obtain the wall temperature of the water-cooled heat exchanger.

[0015] Furthermore, a dual-source low-dew-point closed-loop water-cooled dual-effect heat recovery unit also includes: a fresh air detector and an exhaust air detector;

[0016] The fresh air detector is used to obtain the fresh air temperature and humidity; the outlet air detector is used to obtain the supply air temperature and humidity.

[0017] Furthermore, a dual-source low-dew-point closed-loop water-cooled dual-effect heat recovery unit also includes: a pressurized centrifugal fan, a primary filter, and a medium-efficiency filter;

[0018] Fresh air flows sequentially through a pressurized centrifugal fan, a pre-filter, and a medium-efficiency filter; the pressurized centrifugal fan is used to pressurize the fresh air, the pre-filter is used to perform initial filtration of the fresh air, and the medium-efficiency filter is used to perform secondary filtration of the fresh air.

[0019] According to a second aspect of the present invention, a control method for a dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit is provided, applied to a dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit as described in the first aspect of the present invention, comprising:

[0020] Obtain environmental information;

[0021] Based on the environmental information, the operating mode is confirmed, wherein the operating mode includes dehumidification mode and humidification mode;

[0022] Based on the operating mode and environmental information, the operating status of the main circuit, the opening and closing of the humidifier, the opening degree of the first three-way valve and the second three-way valve, and the heat exchange processing mode of the first heat exchanger and the second heat exchanger are adjusted.

[0023] The environmental information includes fresh air temperature, wall temperature, dew point temperature, internal temperature and / or supply air temperature; the operating status includes cooling status and heating status; and the heat exchange treatment mode includes heating treatment and / or heat and humidity treatment.

[0024] Furthermore, the confirmation process for the operating mode specifically includes:

[0025] Determine whether the dew point temperature is less than the set dew point temperature threshold.

[0026] If so, then confirm that the operating mode is humidification mode;

[0027] If not, then confirm that the operating mode is dehumidification mode.

[0028] Furthermore, when the operating mode is humidification mode, the control process for the main circuit's operating status, the humidifier's on / off state, the opening degree of the first three-way valve and the second three-way valve, and the heat exchange processing mode of the first and second heat exchangers specifically includes:

[0029] The second three-way valve is closed, and the second three-way valve is connected to the two-way flow valve, so the first heat exchanger operates in the heating treatment mode.

[0030] Determine whether the fresh air temperature is within the set first temperature range;

[0031] If so, the main circuit operates in heating mode, the opening of the two-way flow valve is adjusted to the set minimum opening, and the water-cooled heat exchanger and evaporator operate in heating mode.

[0032] Adjust the opening of the first three-way valve to determine if the wall temperature is greater than the set wall temperature threshold; if so, the second three-way valve outputs the fifth chilled water, turns on the humidifier, and adjusts the dew point temperature.

[0033] Furthermore, when the operating mode is dehumidification mode, the control process for the main circuit's operating status, the humidifier's on / off state, the opening degree of the first three-way valve and the second three-way valve, and the heat exchange processing mode of the first and second heat exchangers specifically includes:

[0034] The first heat exchanger operates in a heat and humidity treatment mode, while the main circuit operates in a cooling mode.

[0035] Determine whether the internal temperature, dew point temperature, air supply temperature, and wall temperature of the chamber are all within the corresponding set temperature ranges.

[0036] If so, the water-cooled heat exchanger performs heat exchange, the evaporator and the second heat exchanger operate in a hot and humidified mode, the second three-way valve outputs the ninth chilled water, and the humidifier is turned off.

[0037] Furthermore, the set wall temperature threshold is 3℃.

[0038] The beneficial effects of this invention are: by using externally input chilled water, the temperature of the air output from the third chamber at the air outlet is adjusted, while the temperature of the chilled water return is also adjusted, and the treated chilled water is output back to the outside, thereby meeting the needs of different air supply temperature differences to adapt to changes in indoor heat load, realizing dual-effect heat recovery and utilization, solving the problem of high energy consumption and large demand for electric reheat when using dual cold source low dew point applications, making the unit more efficient, stable and simple.

[0039] The use of a closed-loop chilled water system for condensation saves the need for a separate heat dissipation and delivery system, thus solving the problems of large engineering workload and insufficient installation space caused by the traditional use of air-cooled or water-cooled condensation in dual-source direct expansion units. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of a dual-cold-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit according to an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of a dual-cold-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit provided in another embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the humidification mode of a dual-cold-source, low-dew-point, closed-loop water-cooled dual-effect heat recovery unit provided by the present invention.

[0043] Figure 4 This is a schematic diagram of the dehumidification mode of a dual-cold-source, low-dew-point, closed-loop water-cooled dual-effect heat recovery unit provided by the present invention.

[0044] Reference numerals: 100, compressor; 110, water-cooled heat exchanger; 120, throttling structure; 130, evaporator; 140, four-way valve; 200, housing; 210, air inlet valve; 220, air outlet; 230, partition plate; 240, first chamber; 250, second chamber.

[0045] 300. Pressurized centrifugal fan; 310. Primary filter; 320. Medium-efficiency filter; 330. First heat exchanger; 340. Second heat exchanger; 350. Humidifier; 360. First three-way valve; 370. Second three-way valve; 380. Two-way flow valve.

[0046] 400. Fresh air detector; 410. Temperature detector; 420. Dew point detector; 430. Air outlet detector; 440. Wall temperature detector.

[0047] 500, high-temperature main unit; 600, clean process area. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and should not be construed as limiting the scope of the invention.

[0049] It should be noted that although functional modules are divided in the system diagram, in some cases, the steps shown or described may be executed in a different order than the module division in the system or the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0050] In the description of this invention, it should be noted that, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0051] Reference Figures 1 to 2 In some embodiments of the first aspect of the present invention, a dual-cold-source low-dew-point closed-loop water-cooled dual-effect heat recovery unit includes: a housing 200, a first heat exchanger 330, a second heat exchanger 340, a humidifier 350, a first three-way valve 360, a second three-way valve 370, a main circuit, and a control module.

[0052] The main circuit, the first heat exchanger 330, the second heat exchanger 340, the first three-way valve 360, and the second three-way valve 370 are all located inside the housing 200. The compressor 100, the four-way valve 140, the water-cooled heat exchanger 110, the throttling structure 120, and the evaporator 130 are sequentially connected to form a circuit, thus constituting the main circuit.

[0053] The compressor 100 is connected to the water-cooled heat exchanger 110 through the four-way valve 140. The water-cooled heat exchanger 110 is connected to one end of the throttling structure 120. The other end of the throttling structure 120 is connected to the evaporator 130. The evaporator 130 is connected to the compressor 100 through the four-way valve 140.

[0054] The first heat exchanger 330 is connected to the first port of the first three-way valve 360, the second port of the first three-way valve 360 ​​is connected to the water-cooled heat exchanger 110, and the third port of the first three-way valve 360 ​​is connected to the first port of the second three-way valve 370. The first port of the second three-way valve 370 is connected to the water-cooled heat exchanger 110, the second port of the second three-way valve 370 is connected to the second heat exchanger 340, and the third port of the second three-way valve 370 is bypassed to the second heat exchanger 340.

[0055] The housing 200 is equipped with an air inlet valve 210 and an air outlet 220. Fresh air flows into the interior of the housing 200 through the air inlet valve 210, and the air delivered from the air outlet 220 flows into the clean process area 600 to achieve year-round cooling. The humidifier 350 is located behind the evaporator 130 and is installed at the air outlet 220.

[0056] Based on environmental information, the control module confirms the unit's operating mode and regulates the main circuit, humidifier, first three-way valve, second three-way valve, first heat exchanger, and second heat exchanger.

[0057] When the unit is in dehumidification mode, fresh air flows into the interior of the housing 200 through the air inlet valve 210. The first heat exchanger 330 receives the input chilled water and uses the input chilled water to perform heat exchange treatment on the fresh air to obtain the first air inside the housing, so that the air inside the housing reaches the set dew point temperature and the first chilled water is obtained.

[0058] The first three-way valve 360 ​​receives the first chilled water and divides it into two parts to obtain the second chilled water and the third chilled water. The second chilled water flows into the water-cooled heat exchanger 110.

[0059] The water-cooled heat exchanger 110 performs heat exchange treatment on the second chilled water to obtain the fourth chilled water. The air in the first chamber flows through the evaporator 130. At the same time, the compressor 100 inputs high-temperature and high-pressure gaseous refrigerant into the water-cooled heat exchanger 110 through the four-way valve 140 in a de-powered state. The water-cooled heat exchanger 110 condenses the high-temperature and high-pressure refrigerant into a subcooled liquid. After being throttled by the throttling structure 120, it becomes a low-temperature and low-pressure two-phase refrigerant that flows into the evaporator 130. At the same time, the air in the first chamber flows through the evaporator 130. The evaporator 130 performs heat exchange treatment on the air in the first chamber to obtain the air in the second chamber. The evaporator 130 processes the low-temperature and low-pressure two-phase refrigerant to output low-pressure superheated gas. The low-pressure superheated gas flows back to the compressor 100 through the four-way valve 140 in a de-powered state. The compressor 100 pressurizes and heats up, and this cycle repeats.

[0060] The first three-way valve 360 ​​receives the fourth chilled water, mixes the fourth chilled water with the third chilled water, and the resulting fifth chilled water is transmitted to the second three-way valve 370.

[0061] The second three-way valve 370 receives the fifth chilled water, and then further divides the fifth chilled water into two parts to obtain the sixth chilled water and the seventh chilled water. The sixth chilled water is then transferred to the second heat exchanger 340.

[0062] The air in the second chamber flows through the second heat exchanger 340. The second heat exchanger 340 uses the sixth chilled water to perform heat exchange treatment on the air in the second chamber, resulting in the air in the third chamber and the eighth chilled water.

[0063] The second three-way valve 370 receives the eighth chilled water, mixes the eighth chilled water with the seventh chilled water, and outputs the ninth chilled water to the outside.

[0064] The air inside the third chamber flows into the clean process area 600 from the air outlet 220.

[0065] In this embodiment, during dehumidification mode, the chilled water flow rate is continuously adjusted via the first three-way valve 360 ​​to achieve maximum energy efficiency operation at different frequencies within the compressor 100's operating range. The water flow rate into the second heat exchanger 340 is continuously adjusted via the second three-way valve 370, enabling continuously adjustable supply air temperature. This replaces electric reheating and further regulates the chilled water temperature, resulting in lower energy consumption for the direct expansion unit. Condensation via chilled water achieves high-efficiency operation at ultra-low condensing temperatures. Simultaneously, after heating, the chilled water is used as a heat source to heat the air inside the second chamber at the evaporator 130 outlet. The cooled chilled water then flows back to the outside, achieving dual-effect heat recovery and a large temperature difference in chilled water treatment, making the unit more efficient, stable, and simple.

[0066] When the unit is in humidification mode, for fresh air: fresh air flows into the interior of the housing 200 through the air inlet valve 210. The first heat exchanger 330 receives the input chilled water and uses the input chilled water to perform heat exchange treatment on the fresh air to obtain the first housing air and the first chilled water.

[0067] The first three-way valve 360 ​​receives the first chilled water and divides it into two parts to obtain the second chilled water and the third chilled water. The second chilled water flows into the water-cooled heat exchanger 110.

[0068] The water-cooled heat exchanger 110 performs heat exchange treatment on the second chilled water to obtain the fourth chilled water. The air in the first chamber flows through the evaporator 130. At the same time, the compressor 100 inputs high-temperature and high-pressure gaseous refrigerant into the evaporator 130 through the energized four-way valve 140. The evaporator 130 condenses it into high-pressure subcooled refrigerant. Meanwhile, the air in the first chamber flows through the evaporator 130 and performs heat exchange treatment on the air in the first chamber to obtain the air in the second chamber. The high-pressure subcooled refrigerant is throttled into a low-temperature and low-pressure two-phase refrigerant through the throttling structure 120 and enters the water-cooled heat exchanger 110. The water-cooled heat exchanger 110 processes it to obtain low-pressure superheated gas, which is input into the compressor 100 through the energized four-way valve 140. The compressor 100 pressurizes and heats up, and this cycle is repeated.

[0069] The first three-way valve 360 ​​receives the fourth chilled water, mixes the fourth chilled water with the third chilled water, and the resulting fifth chilled water is transmitted to the second three-way valve 370.

[0070] The air inside the second chamber passes through the second heat exchanger 340, and the humidifier 350 humidifies the air inside the second chamber to obtain the air inside the third chamber.

[0071] The second three-way valve 370 receives the fifth chilled water and, through the third port that bypasses the second heat exchanger 340, directly outputs the fifth chilled water to the outside without entering the second heat exchanger 340;

[0072] The air inside the third chamber flows into the clean process area 600 from the air outlet 220.

[0073] In this embodiment, under humidification mode, the system leverages the opposing needs of preheating the fresh air before centralized humidification and cooling the indoor environment. This achieves preheating and cold recovery of externally input chilled water, as well as cold recovery during heat pump heating operation. The direct expansion system avoids the problem of frost formation during heat pump operation despite low outdoor temperatures and high humidity, thus ensuring stable and efficient operation of the heat pump system under cleanroom environmental control. Simultaneously, the cooled medium-to-high temperature chilled water effectively reduces the output of the high-temperature main unit (500°C), indirectly achieving energy-saving application of the fresh air cooling source. By evaporating the refrigerant with high-temperature chilled water, the main circuit achieves high-efficiency heat pump operation at a relatively stable water temperature. Simultaneously, the cooled chilled water is used as a cold source to supply indoor circulating units or dry coils to cool the cleanroom process area (600°C), achieving dual-effect heat recovery utilization of chilled water and fresh air, making the unit more efficient, stable, and simple.

[0074] The heat exchange process includes: heat and humidity treatment and / or heating treatment. Environmental information includes: fresh air temperature, wall temperature, dew point temperature, internal temperature and / or supply air temperature. The operating modes include: dehumidification mode and humidification mode.

[0075] This invention breaks away from the situation where the overall energy efficiency of dual-source low dew point applications based on the combination of chilled water at 7℃ or 14℃ and direct expansion systems is relatively low. It solves the problems of large engineering volume and insufficient installation space for the heat dissipation part of dual-source direct expansion units using cooling water. It utilizes closed-loop chilled water to achieve condensation, saving on heat dissipation and transportation systems, while also solving the problems of poor water quality in open cooling towers and uneven heat exchange caused by changing flow rates.

[0076] This technology solves the problem of high reheat demand in low dew point applications with dual cold sources, achieving dual-effect heat recovery and improving overall energy efficiency. It also addresses the issue of limited adjustable cooling water flow in traditional water-cooled direct expansion units during frequency conversion operation, leading to energy consumption in the cooling water system due to high flow rates and small temperature differences. Furthermore, it resolves the problem of unstable compressor operation and unit instability caused by excessively low cooling water temperatures during low-load operation in transitional seasons. Finally, it addresses the issue of increased unit head consumption resulting from the use of simplified series connection when establishing large temperature differences in chilled water in existing technologies.

[0077] Under high cleanliness requirements, the humidification mode of this invention can be used for fresh air in winter to heat and humidify the fresh air, providing cooling for the clean process area 600. The humidification mode of the unit operates in a circulating manner, reducing the chilled water temperature and sharing the cooling load of the high-temperature main unit 500. This eliminates the need for electric preheating or four-pipe hot water heating to increase the fresh air temperature, improving overall energy efficiency. It also solves the problem of frost formation on the outdoor evaporator due to ambient temperature during winter heating, and the problem of inconsistent supply air temperature fluctuations during defrosting. Furthermore, a dehumidification mode is used in summer to prevent the unit from being affected by extreme external temperatures during summer cooling operation, thus avoiding a decrease in cooling capacity and a sharp increase in energy consumption.

[0078] Reference Figures 1 to 2 In some embodiments of the present invention, a dual-source low dew point closed-loop water-cooled dual-effect heat recovery unit further includes: a partition plate 230, a pressurized centrifugal fan 300, a primary filter 310, a medium-efficiency filter 320, and a two-way flow valve 380.

[0079] A partition 230 is disposed inside the housing 200, dividing the interior of the housing 200 into a first chamber 240 and a second chamber 250. The first chamber 240 houses a compressor 100, a four-way valve 140, and a water-cooled heat exchanger 110. The second chamber 250 houses a pressurized centrifugal fan 300, a primary filter 310, a secondary filter 320, a first heat exchanger 330, an evaporator 130, a throttling structure 120, a second heat exchanger 340, a humidifier 350, a second three-way valve 370, and a first three-way valve 360. The second chamber 250 is equipped with an air inlet valve 210 and an air outlet 220.

[0080] Fresh air can enter the interior of the second chamber 250 through the air inlet valve 210, and after being pressurized by the pressurized centrifugal fan 300, it can be filtered first by the primary filter 310 and then filtered again by the secondary filter 320. It can then flow sequentially through the first heat exchanger 330, the evaporator 130, the second heat exchanger 340 and the humidifier 350, and finally flow out from the air outlet 220 to the clean process area 600.

[0081] The two-way flow valve 380 is located outside the housing 200. The third port of the second three-way valve 370 is connected to the two-way flow valve 380 via a bypass second heat exchanger 340. The second three-way valve 370 outputs either the fifth or ninth chilled water through the two-way flow valve 380.

[0082] In this embodiment, there are no restrictions on the installation position of the three-way valve, the use of multiple two-way flow valves 380 to replace the three-way valve, or the use of an energy valve to replace the two-way valve.

[0083] Reference Figures 1 to 2 In some embodiments of the present invention, a dual-source low dew point closed-loop water-cooled dual-effect heat recovery unit further includes: a dew point detector 420, a temperature detector 410, and a wall temperature detector 440.

[0084] The wall temperature detector 440 is installed on the pipeline of the water-cooled heat exchanger 110 and is located inside the first cavity 240. The pipeline is connected to the first three-way valve 360 ​​and the second three-way valve 370 respectively. The wall temperature detector 440 is used to obtain the wall temperature of the water-cooled heat exchanger 110.

[0085] The dew point detector 420 is located behind the evaporator 130, near the air outlet 220, inside the second cavity 250. The dew point detector 420 is used to obtain the dew point temperature inside the second cavity 250. In this embodiment, under saturation conditions, the dry-bulb temperature detected by the dew point detector 420 can be the dew point temperature.

[0086] Temperature detector 410 is located in front of evaporator 130 and inside second chamber 250. Temperature detector 410 is used to obtain the internal temperature of second chamber 250.

[0087] Reference Figures 1 to 2 In some embodiments of the present invention, a dual-source low dew point closed-loop water-cooled dual-effect heat recovery unit further includes: a fresh air detector 400 and an exhaust air detector 430.

[0088] The fresh air detector 400 is installed at the air inlet valve 210. The fresh air detector 400 is used to detect the fresh air at the air inlet valve 210 and obtain the fresh air temperature and humidity.

[0089] An air outlet detector 430 is installed at the air outlet 220. The air outlet detector 430 is used to detect the fresh air at the air inlet valve 210 and obtain the fresh air temperature and humidity.

[0090] In this embodiment, the dew point temperature can be calculated by inversely using the temperature and humidity of the fresh air and the supply air.

[0091] In this embodiment, the valve opening, humidifier 350 operation, compressor 100 frequency, and heat exchanger heat exchange mode can be adjusted according to environmental information such as fresh air temperature, fresh air humidity, supply air temperature, outlet air humidity, wall temperature, dew point temperature, and box temperature.

[0092] A control method for a dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit, as described in some embodiments of the second aspect of the present invention, applies the dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit described in the embodiments of the first aspect of the present invention. The control method includes the following steps:

[0093] S100, acquires environmental information.

[0094] In this embodiment, all valves in the unit are initialized, the pressurized centrifugal fan is run, the dew point temperature is detected by a dew point detector, the internal temperature of the chamber is detected by a temperature detector, the wall temperature of the water-cooled heat exchanger is detected by a wall temperature detector, the fresh air temperature is detected by a fresh air detector, and the supply air temperature is detected by an exhaust air detector.

[0095] S200: Based on the environmental information obtained from S100, confirm the unit's operating mode.

[0096] In this embodiment, the environmental information obtained in S100 is used to confirm the unit's operating mode. The unit's operating modules include: a humidification mode, in which the unit can operate without frost in winter to achieve constant temperature and humidity; and a dehumidification mode, in which the unit can operate with heat recovery in summer to achieve constant temperature and humidity.

[0097] S300, based on the operating mode confirmed by S200 and the environmental information obtained by S100, regulates the operating status of the main circuit, the opening and closing of the humidifier, the opening degree of the first three-way valve and the second three-way valve, and the heat exchange processing mode of the first heat exchanger and the second heat exchanger.

[0098] In this embodiment, based on the operating mode confirmed in S200 and the environmental information obtained in S100, the operating state of the main circuit is adjusted, wherein the operating state includes a cooling state and a heating state. The humidifier is controlled to open or close, the opening degree of the first three-way valve is adjusted, the opening degree of the second three-way valve is adjusted, and the heat exchange processing mode of the first heat exchanger and the heat exchange processing mode of the second heat exchanger are adjusted.

[0099] This invention solves the problem of achieving constant temperature and humidity heat recovery in summer dehumidification mode and frost-free constant temperature and humidity operation of heat pump in winter humidification mode based on chilled water. Both can be used under extreme high temperature or extreme low temperature conditions, and can be achieved stably, simply, economically and efficiently through different circulation methods.

[0100] In some embodiments of the present invention, in S200, confirming the operating mode specifically includes:

[0101] S210, confirm whether the dew point temperature in S100 is less than the set dew point temperature threshold.

[0102] S211, if so, the unit's operating mode is humidification mode;

[0103] S212, if not, the unit's operating mode is dehumidification mode.

[0104] In this embodiment, the dew point temperature in the environmental information is compared with the set dew point temperature threshold.

[0105] When the dew point temperature is lower than the set dew point temperature threshold, the current unit adopts humidification mode;

[0106] When the dew point temperature is greater than the set dew point temperature threshold, the current unit adopts dehumidification mode.

[0107] The required dew point temperature can be calculated by using the fresh air temperature and humidity and supply air temperature and humidity in S100.

[0108] Reference Figure 3In some embodiments of the present invention, when the unit adopts humidification mode, the control process in S300 specifically includes:

[0109] S310, close the second three-way valve, the second three-way valve bypasses the second heat exchanger, the first heat exchanger uses externally input chilled water to heat the fresh air, to obtain the first box air and the first chilled water.

[0110] In this embodiment, in humidification mode, the second three-way valve is closed, allowing it to bypass the second heat exchanger. The second three-way valve is directly connected to the two-way flow valve. The first heat exchanger uses chilled water from the high-temperature main unit to heat the fresh air, preheating it to obtain the first chamber air and the first cooling water.

[0111] S311, determine whether the fresh air temperature is within the set first temperature range;

[0112] In this embodiment, it is confirmed whether the fresh air temperature is within a set first temperature range, wherein the lowest threshold in the set first temperature range is 14°C.

[0113] S312, if so, the main circuit operates in heating mode, the two-way flow valve is adjusted to the set minimum opening, the water-cooled heat exchanger heats the second chilled water to obtain the fourth chilled water, and the evaporator heats the air in the first box to obtain the air in the second box.

[0114] In this embodiment, the two-way flow valve is adjusted to the set minimum opening degree according to the set temperature adjustment frequency.

[0115] The main circuit operates in heating mode: the water-cooled heat exchanger performs heat exchange treatment on the second chilled water to obtain the fourth chilled water. The compressor inputs high-temperature and high-pressure gaseous refrigerant into the evaporator through the energized four-way valve. The evaporator condenses it into high-pressure subcooled refrigerant. The high-pressure subcooled refrigerant is throttled into low-temperature and low-pressure two-phase refrigerant through the throttling structure and enters the water-cooled heat exchanger. The water-cooled heat exchanger processes it to obtain low-pressure superheated gas, which is input into the compressor through the energized four-way valve. The compressor pressurizes and heats up, and this cycle repeats.

[0116] S313, adjust the opening of the first three-way valve to determine whether the wall temperature is greater than the set wall temperature threshold; if so, the second three-way valve outputs the fifth chilled water and turns on the humidifier to adjust the dew point temperature.

[0117] In this embodiment, the first three-way valve receives the first chilled water and divides it into two parts to obtain the second chilled water and the third chilled water. The second chilled water flows through a water-cooled heat exchanger to obtain the fourth chilled water. The fourth chilled water is mixed with the third chilled water to form the fifth chilled water, which is then transmitted to the second three-way valve.

[0118] The opening of the first three-way valve is adjusted to ensure that the wall temperature of the water-cooled heat exchanger is greater than the set wall temperature threshold, i.e., the wall temperature is greater than 3℃.

[0119] When the wall temperature is greater than 3°C, the second three-way valve outputs the fifth chilled water and turns on the humidifier. The humidifier humidifies the air in the second chamber after it has been processed by the evaporator, thereby obtaining the air in the third chamber. The humidifier is used to adjust the dew point temperature to the set dew point temperature threshold.

[0120] It should be noted that this embodiment also includes: when the fresh air temperature is lower than the minimum threshold of 14°C, adjusting the opening of the two-way flow valve to be greater than the set minimum opening. The first heat exchanger heats the fresh air, preheating it to 10°C to 14°C to obtain the first chamber air. The main circuit operates in heating mode, adjusting the opening of the first three-way valve to achieve a wall temperature greater than 3°C. The second three-way valve outputs the fifth type of chilled water, turning on the humidifier to adjust the dew point temperature to the set dew point temperature threshold.

[0121] When the fresh air temperature is higher than the highest temperature value in the first set temperature range, the opening of the two-way flow valve is adjusted according to the set temperature to limit the operation of the compressor and turn on the humidifier to adjust the dew point temperature to the set dew point temperature threshold.

[0122] Through S310 to S313, the opening of the two-way flow valve and the operation of the main circuit's heating mode are adjusted according to the fresh air temperature to treat the chilled water and fresh air, thus solving the frosting phenomenon of the evaporator at low temperature and high humidity. Based on the wall temperature, the opening of the first three-way valve is adjusted, and the humidifier is turned on to achieve constant temperature and humidity in the humidification mode. The main circuit operates as a high-efficiency heat pump at a relatively stable water temperature. The cooled chilled water can be used as a cold source to supply indoor circulating units or dry coil cooling clean process areas, achieving dual-effect heat recovery and utilization of chilled water and fresh air, making the unit more efficient, stable, and simple.

[0123] Reference Figure 4 In some embodiments of the present invention, when the unit adopts dehumidification mode, the control process in S300 specifically includes:

[0124] S320, the first heat exchanger uses externally input chilled water to perform heat and humidity treatment on the fresh air, resulting in the first box air and the first chilled water, and the main circuit operates in a cooling state.

[0125] In this embodiment, in dehumidification mode, the first heat exchanger uses chilled water input from the high-temperature host to perform heat and humidity treatment on the fresh air, pre-dehumidifying and cooling the fresh air to obtain the first box air and the first cooling water, so that the first box air reaches the set dew point temperature.

[0126] The main circuit operates in refrigeration mode: the compressor inputs high-temperature, high-pressure gaseous refrigerant to the water-cooled heat exchanger through a four-way valve in the power-off state. The water-cooled heat exchanger condenses the high-temperature, high-pressure refrigerant into a subcooled liquid. After being throttled by the throttling structure, the refrigerant is converted into a low-temperature, low-pressure two-phase refrigerant and flows into the evaporator. The evaporator processes the low-temperature, low-pressure two-phase refrigerant and outputs low-pressure superheated gas. The low-pressure superheated gas flows back to the compressor through the four-way valve in the power-off state. The compressor pressurizes and heats up, and this cycle repeats.

[0127] S321, determine whether the temperature inside the chamber is within the set second temperature range, whether the dew point temperature is within the set third temperature range, whether the supply air temperature is within the set fourth temperature range, and whether the wall temperature is within the set fifth temperature range.

[0128] In this embodiment, it is determined whether the temperature inside the chamber is within the set second temperature range (17℃-18℃), whether the dew point temperature is within the set third temperature range (2℃-3℃), whether the air supply temperature is within the set fourth temperature range (18℃-20℃), and whether the wall temperature is within the set fifth temperature range (21℃-24℃).

[0129] S322, if so, the water-cooled heat exchanger performs heat exchange treatment on the second chilled water, the evaporator performs heat and humidity treatment on the air in the first chamber, the humidifier is turned off, the second heat exchanger performs heat and humidity treatment on the air in the second chamber, and the second three-way valve outputs the ninth chilled water.

[0130] In this embodiment, when the temperatures in the environmental information are all within the corresponding set temperature range, the unit's valves maintain their current opening degree. The first three-way valve receives the first chilled water and distributes it into two parts to obtain the second chilled water and the third chilled water. The second chilled water flows into the water-cooled heat exchanger.

[0131] The water-cooled heat exchanger performs heat exchange treatment on the second chilled water to obtain the fourth chilled water, and the evaporator performs heat and humidity treatment on the air in the first chamber to obtain the air in the second chamber.

[0132] The first three-way valve receives the fourth chilled water, mixes the fourth chilled water with the third chilled water, and the resulting fifth chilled water is then transferred to the second three-way valve.

[0133] The second three-way valve receives the fifth chilled water, and then further divides the fifth chilled water into two parts to obtain the sixth chilled water and the seventh chilled water. The sixth chilled water is then transferred to the second heat exchanger.

[0134] The second heat exchanger uses the sixth chilled water to perform heat and humidity treatment on the air inside the second chamber, resulting in the air inside the third chamber and the eighth chilled water. The air inside the third chamber flows into the clean process area through the air outlet.

[0135] The second three-way valve receives the eighth chilled water and mixes it with the seventh chilled water. The resulting ninth chilled water is then output to the outside through the two-way flow valve.

[0136] It should be noted that this embodiment also includes: when the temperature inside the chamber is not within the set second temperature range (17℃-18℃), adjusting the opening of the two-way flow valve and ensuring that it is the set minimum opening.

[0137] When the dew point temperature is not within the set third temperature range (2℃-3℃), adjust the compressor frequency;

[0138] When the supply air temperature is not within the set fourth temperature range (18℃-20℃), adjust the opening of the second three-way valve;

[0139] When the wall temperature is not within the set fifth temperature range (21℃-24℃), adjust the opening of the first three-way valve.

[0140] By adjusting the opening of the two-way flow valve, the first three-way valve, and the second three-way valve based on the environmental temperature information via S320 to S322, and by adjusting the compressor frequency, constant temperature and humidity can be achieved in dehumidification mode, and high-efficiency operation of the main circuit at ultra-low condensing temperature can be achieved. The heated chilled water is used as a heat source to heat the air inside the second chamber at the evaporator outlet. The cooled chilled water is then returned to the outside, achieving double-effect heat recovery and a large temperature difference in chilled water treatment, making the unit more efficient, stable, and simple.

[0141] Those skilled in the art can implement the present invention in various modifications without departing from the scope and spirit of the invention. For example, a feature of one embodiment can be used in another embodiment to obtain yet another embodiment. The preferred embodiments of the present disclosure have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present disclosure. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and spirit of the present disclosure should be within the scope of the claims of the present disclosure.

Claims

1. A dual-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit, characterized in that, include: The enclosure, main circuit, first heat exchanger, first three-way valve, second three-way valve, humidifier, control module, and second heat exchanger; The main circuit includes a compressor, a four-way valve, a water-cooled heat exchanger, a throttling structure, and an evaporator connected in sequence. The control module determines the operating mode based on environmental information and regulates the main circuit, humidifier, first three-way valve, second three-way valve, first heat exchanger, and second heat exchanger. The environmental information includes fresh air temperature, wall temperature, dew point temperature, internal temperature, and / or supply air temperature. The operating modes include dehumidification mode and humidification mode. The first heat exchanger is used to perform heat exchange treatment on externally input chilled water and fresh air to obtain first chilled water and first chamber air. The first three-way valve is used to divide the first chilled water into second chilled water and third chilled water, and to mix the third chilled water and fourth chilled water to form fifth chilled water. The water-cooled heat exchanger is used to perform heat exchange treatment on the second chilled water to obtain fourth chilled water. The evaporator is used to perform heat exchange treatment on the first chamber air to obtain second chamber air. When the operating mode is dehumidification mode, the second three-way valve divides the fifth chilled water into the sixth chilled water and the seventh chilled water, mixes the seventh chilled water and the eighth chilled water to form the ninth chilled water and outputs it, and the second heat exchanger is used to perform heat exchange treatment on the sixth chilled water and the air inside the second chamber to obtain the eighth chilled water and the output air inside the third chamber. When the operating mode is humidification mode, the second three-way valve outputs the fifth chilled water, and the humidifier is used to humidify the air in the second chamber to obtain the output air in the third chamber.

2. The dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit according to claim 1, characterized in that, Also includes: Two-way flow valve; The two-way flow valve is located outside the casing and is connected to the second three-way valve through the second heat exchanger.

3. The dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit according to claim 1, characterized in that, Also includes: Dew point detector, temperature detector, and wall temperature detector; The dew point detector is used to obtain the dew point temperature, the temperature detector is used to obtain the temperature inside the chamber, and the wall temperature detector is used to obtain the wall temperature of the water-cooled heat exchanger.

4. The dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit according to claim 1, characterized in that, Also includes: Fresh air detector and exhaust air detector; The fresh air detector is used to obtain the fresh air temperature and humidity. The air outlet detector is used to obtain the air supply temperature and air supply humidity.

5. The dual-source low-dew-point closed-loop water-cooled double-effect heat recovery unit according to claim 1, characterized in that, Also includes: Pressurized centrifugal fan, pre-filter and medium-efficiency filter; Fresh air flows sequentially through a pressurized centrifugal fan, a pre-filter, and a medium-efficiency filter; The pressurized centrifugal fan is used to pressurize the fresh air, the primary filter is used to perform initial filtration of the fresh air, and the medium-efficiency filter is used to perform secondary filtration of the fresh air.

6. A control method for a dual-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit, characterized in that, The dual-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit, applicable to any one of claims 1 to 5, comprises: Obtain environmental information; Based on the environmental information, the operating mode is confirmed, wherein the operating mode includes dehumidification mode and humidification mode; Based on the operating mode and environmental information, the operating status of the main circuit, the opening and closing of the humidifier, the opening degree of the first three-way valve and the second three-way valve, and the heat exchange processing mode of the first heat exchanger and the second heat exchanger are adjusted. The environmental information includes fresh air temperature, wall temperature, dew point temperature, internal temperature and supply air temperature; the operating status includes cooling status and heating status; and the heat exchange treatment mode includes heating treatment and / or heat and humidity treatment.

7. The control method for a dual-cold-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit according to claim 6, characterized in that, The process for confirming the operating mode specifically includes: Determine whether the dew point temperature is less than the set dew point temperature threshold. If so, then confirm that the operating mode is humidification mode; If not, then confirm that the operating mode is dehumidification mode.

8. The control method for a dual-cold-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit according to claim 7, characterized in that, When the operating mode is humidification mode, the specific control process for the main circuit's operating status, the humidifier's on / off state, the opening degree of the first three-way valve and the second three-way valve, and the heat exchange mode of the first and second heat exchangers includes: The second three-way valve is closed, and the second three-way valve is connected to the two-way flow valve, so the first heat exchanger operates in the heating treatment mode. Determine whether the fresh air temperature is within the set first temperature range; If so, the main circuit operates in heating mode, the opening of the two-way flow valve is adjusted to the set minimum opening, and the water-cooled heat exchanger and evaporator operate in heating mode. Adjust the opening of the first three-way valve to determine if the wall temperature is greater than the set wall temperature threshold; if so, the second three-way valve outputs the fifth chilled water, turns on the humidifier, and adjusts the dew point temperature.

9. The control method for a dual-cold-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit according to claim 7, characterized in that, When the operating mode is dehumidification mode, the specific control process for the main circuit's operating status, the humidifier's on / off state, the opening degree of the first three-way valve and the second three-way valve, and the heat exchange processing mode of the first and second heat exchangers includes: The first heat exchanger operates in a heat and humidity treatment mode, while the main circuit operates in a cooling mode. Determine whether the internal temperature, dew point temperature, air supply temperature, and wall temperature of the chamber are all within the corresponding set temperature ranges. If so, the water-cooled heat exchanger performs heat exchange, the evaporator and the second heat exchanger operate in a hot and humidified mode, the second three-way valve outputs the ninth chilled water, and the humidifier is turned off.

10. The control method for a dual-cold-source, low-dew-point, closed-loop water-cooled double-effect heat recovery unit according to claim 8, characterized in that, The set wall temperature threshold is .

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