CN-116119762-B - Solar heat pump coupling type multistage humidifying and dehumidifying water treatment system and working method thereof

Abstract

A solar heat pump coupling multi-stage humidifying and dehumidifying water treatment system comprises a water treatment circulation subsystem, a solar hot water circulation subsystem and a compression heat pump circulation subsystem, wherein raw material liquid is heated by hot water prepared by solar energy and a compression heat pump condenser in a cooperative mode, sequentially enters a two-stage humidifier to exchange heat with air, preheats air and discharges the air, circulating air sequentially carries out two-time humidifying through the two-stage humidifier, and carries out gradual cooling and dehumidifying through a precooler, a dehumidifier and a heat pump evaporator, the discharged raw material liquid is preheated and then carries out the next circulation, and condensed water obtained by condensing steam in the air enters a heat pump subcooler to exchange heat and is collected into a fresh water tank. According to the invention, the two-stage humidification is finished by utilizing the hot raw material liquid after the one-stage humidification, the multi-stage dehumidification is finished by utilizing the precooler, the high-flow raw material liquid and the heat pump evaporator, and the all-weather fresh water supply requirement is realized by utilizing the solar water heating system and simultaneously introducing the heat pump system.

Inventors

• SHEN JIUBING
• WANG BINGDONG
• WEI WENBIN
• CHEN YANG
• JIANG LELE

Assignees

• 江苏科技大学

Dates

Publication Date

20260512

Application Date

20230207

Claims (5)

1. 1. A solar heat pump coupling multi-stage humidifying and dehumidifying water treatment system comprises a water treatment circulation subsystem, a solar hot water circulation subsystem and a compression heat pump circulation subsystem, wherein the water treatment circulation subsystem comprises a first water pump (1), a dehumidifier (2), a first three-way regulating valve (3), a precooler (4), a second three-way regulating valve (5), a solution heat exchanger (6), a condenser (7), a second humidifier (8), a second water pump (9), a first humidifier (10), a first fan (11), a second fan (12), a preheater (13), an evaporator (14), a subcooler (15), a condenser (7), A fresh water tank (16), a raw material liquid is connected to an inlet (a 1) of a dehumidifier (2) through a pipeline through a flow regulating valve (23) and a first water pump (1), an outlet (a 2) of the dehumidifier (2) is connected to an inlet (b 1) of a first three-way regulating valve (3) through a pipeline, an outlet (b 3) of the first three-way regulating valve (3) is directly connected to a subsequent drainage device, the outlet (b 2) is connected to a solution inlet (c 1) of a precooler (4) through a pipeline, a solution outlet (c 2) of the precooler (4) is connected to an inlet (d 1) of a second three-way regulating valve (5) through a pipeline, an outlet (d 2) of the second three-way regulating valve (5) is connected to an inlet (f 1) of a solution heat exchanger (6) through a pipeline through a first electromagnetic valve (24), an outlet (d 3) of the second three-way regulating valve (5) is connected to an inlet (e 1) of a condenser (7) through a pipeline, an outlet (e 2) of the condenser (7) and an outlet (2) of the solution heat exchanger (6) are connected to a second humidifier (8) through a pipeline through a second water pump (8) through a common inlet (1) of the second water pump (8 h), the bottom outlet of the first humidifier (10) is connected to the concentrated solution inlet (i 1) of the preheater (13) through a pipeline, the concentrated solution outlet (i 2) of the preheater (13) is connected to the subsequent drainage equipment through a pipeline through a first stop valve (26), the air is connected to the air inlet (c 3) of the precooler (4) through a pipeline from the top air outlet of the second humidifier (8), the air outlet (c 4) of the precooler (4) is connected to the top air inlet of the dehumidifier (2) through a pipeline, the air outlet (a 3) of the dehumidifier (2) is connected to the top air inlet of the evaporator (14) through a pipeline, the air outlet (j 1) of the evaporator (14) is connected to the air inlet (i 3) of the preheater (13) through a pipeline, the air outlet (i 4) of the preheater (13) is connected to the air inlet (h 2) of the first humidifier (10) through a pipeline through a second fan (12), the top air outlet of the first humidifier (10) is connected to the top air inlet (c 4) of the precooler (8) through a pipeline, the air outlet (a 3) of the second fan (11) is connected to the top air inlet of the dehumidifier (2) through a pipeline, the air outlet (j 1) of the evaporator (14) is connected to the condensed water outlet (3) of the evaporator (2) is connected to the bottom (3) of the evaporator (2) through a pipeline, the condensed water outlet (k 4) of the subcooler (15) is connected to the fresh water tank (16) through a pipeline, and the bottom outlet of the fresh water tank (16) is supplied to a user for use through a pipeline through a second stop valve (27); The solar water heating subsystem comprises a solar water heater (33), a heat preservation water tank (20), a solution heat exchanger (6), a third water pump (21) and a three-way electromagnetic valve (22), wherein the makeup water is connected to a makeup water inlet (n 3) of the solar water heater (33) through a third stop valve (28) by a pipeline, a hot water outlet (n 2) of the solar water heater (33) is connected to an inlet of the heat preservation water tank (20) through a pipeline, a lower end outlet of the heat preservation water tank (20) is connected to an inlet (f 3) of the solution heat exchanger (6) through a pipeline through a second electromagnetic valve (25), an outlet (f 4) of the solution heat exchanger (6) is connected to an inlet (m 1) of the three-way electromagnetic valve (22) through a pipeline, the outlet (m 3) of the three-way electromagnetic valve (22) is connected to an inlet (n 1) of the solar water heater (33) through a pipeline, and the outlet (m 2) of the three-way electromagnetic valve (22) is connected to a subsequent drainage device through a pipeline; The compression heat pump circulation subsystem comprises a compressor (17), a condenser (7), a subcooler (15), a liquid storage tank (18), a throttle valve (19) and an evaporator (14), wherein a refrigerant outlet of the compressor (17) is connected to a refrigerant inlet (e 3) of the condenser (7) through a pipeline, a refrigerant outlet (e 4) of the condenser (7) is connected to a refrigerant inlet (k 1) of the subcooler (15) through a pipeline, a refrigerant outlet (k 2) of the subcooler (15) is connected to an inlet of the liquid storage tank (18) through a pipeline, a lower refrigerant outlet of the liquid storage tank (18) is connected to a refrigerant inlet (j 2) of the evaporator (14) through a throttle valve (19) through a pipeline, and a refrigerant outlet (j 3) of the evaporator (14) is connected to a refrigerant inlet of the compressor (17) through a pipeline; a liquid level controller (29) is arranged in the heat preservation water tank (20), and control signals of the liquid level controller (29) are respectively connected with a first electromagnetic valve (24) and a second electromagnetic valve (25) through wires; A first temperature controller (30) is arranged on a pipeline of an inlet (g 1) of the second humidifier (8), and control signals of the first temperature controller (30) are respectively connected with the compressor (17) and the second three-way regulating valve (5) through wires; a second temperature controller (31) is arranged on a pipeline of an outlet (j 1) of the evaporator (14), and a control signal of the second temperature controller (31) is connected to the flow regulating valve (23) through a wire; the inlet (c 1) pipeline of the precooler (4) is provided with a flow controller (32), and a control signal of the flow controller (32) is connected to the first three-way regulating valve (3) through a pipeline.
2. 2. A method of operating a solar heat pump coupled multi-stage humidification and dehumidification water treatment system of claim 1, comprising a water treatment cycle subsystem method of operation, a solar hot water cycle subsystem method of operation, and a compression heat pump cycle subsystem method of operation: (1) Working method of water treatment circulation subsystem When the system is initially operated, a first water pump (1), a third water pump (21), a first fan (11) and a second fan (12) are started, a first three-way regulating valve (3) and a second three-way regulating valve (5) are electrified, a compressor (17) is started, raw material liquid is pumped into the system by the first water pump (1) and is shunted into the second three-way regulating valve (5) after passing through a dehumidifier (2), the first three-way regulating valve (3) and a precooler (4), one path of raw material liquid enters a solution heat exchanger (6) to be heated and heated, the other path of raw material liquid enters a condenser (7) to be heated and heated, and then is converged and sprayed into the second humidifier (8) to form uniform high Wen Yemo to be subjected to heat mass exchange with air entering from the bottom, hot and wet air is discharged from the top outlet of the second humidifier (8) to enter the precooler (4) to preheat the raw material liquid, and when the second humidifier (8) reaches a set liquid level, the second water pump (9) is started, and the first stop valve (26) is started, and the system enters a normal operation stage; When the system is in normal operation, raw material liquid is pumped into the system by a first water pump (1) after the flow rate is regulated by a flow regulating valve (23), the wet air entering from the top inlet of the dehumidifier (2) is cooled and dehumidified in a large flow rate in the dehumidifier (2), the temperature of the raw material liquid is regulated by a first three-way regulating valve (3) after being lifted, the flow rate for maintaining the optimal air-liquid ratio of water produced by the system is regulated, the other raw material liquid enters a precooler (4) from an outlet (b 2) of the first three-way electromagnetic valve (3), the rest raw material liquid is discharged from the system from the outlet (b 3), after the solution in the precooler (4) absorbs hot wet air condensation heat to obtain a large temperature rise, the solution is continuously led into a second three-way electromagnetic valve (5) for diversion, and respectively enters a solution heat exchanger (6) to absorb the heat of high-temperature water in the solar hot water system and then is converged into a second humidifier (8) to be uniform and high Wen Yemo for exchange with wet air entering from the bottom, the solution which is not evaporated and has small temperature concentration change, the solution which is discharged from the second humidifier (8) is continuously enters a second water pump (10) from the bottom of the second humidifier (9), the concentrated solution flows out from the bottom outlet of the first humidifier (10) and enters the preheater (13) to preheat hot and humid air, and then the hot and humid air is discharged out of the system through the first stop valve (26), the cold and humid air in the preheater (13) absorbs heat of the concentrated solution and then is pressurized and sent into the first humidifier (10) to exchange with a uniform high-temperature liquid film therein through the second fan (12), the obtained hot and humid air continuously flows out from the top outlet and enters the second humidifier (8) to exchange with the high-temperature liquid film through the first fan (11), the enthalpy-increasing humidification becomes hot and humid air, part of sensible heat in the precooler (4) is released to preheat raw material liquid, the temperature is reduced to below the dew point temperature, and then the hot and humid air is sequentially introduced into the dehumidifier (2) to be cooled and dehumidified by high-flow raw material liquid cooling and then introduced into the evaporator (14) to be cooled and dehumidified by low-temperature low-pressure refrigerant liquid, the temperature and the humidity of the humid air are further reduced, and a large amount of fresh water is separated out, the fresh water generated by condensation of the dehumidifier (2) and the evaporator (14) enters the supercooler (15) to be heated into a hot water tank (16) for subsequent use; (2) Working method of solar hot water circulation subsystem When the solar heating condition is not met at night, the stored high-temperature water in the heat preservation water tank (20) is continuously introduced into the solution heat exchanger (6) for heat exchange, and the heat exchanged high-temperature water is discharged from the third water pump (21) to the system through the outlet (m 2) of the three-way electromagnetic valve (22); (3) Working method of compression heat pump circulation subsystem After the high-temperature high-pressure refrigerant gas generated by compression of the compressor (17) enters the condenser (7) to condense, release heat and heat raw material liquid, the raw material liquid continuously enters the subcooler (15) to heat fresh water while the subcooling degree of the refrigerant is improved, the refrigerant flowing out of the subcooler (15) is connected into the liquid storage tank (18), the refrigerant liquid flowing out of the bottom of the liquid storage tank (18) enters the throttle valve (19) to be throttled and then enters the evaporator (14) to absorb heat to cool and dehumidify so as to generate fresh water, and the refrigerant gas flowing out of the evaporator (14) is introduced into the compressor (17) to be compressed and retracted into the next step for circulation.
3. 3. The method of operating a solar heat pump coupled multi-stage humidification and dehumidification water treatment system of claim 2, wherein the first solenoid valve (24) and the second solenoid valve (25) are controlled by a liquid level of a liquid level controller (29), and the first solenoid valve (24) and the second solenoid valve (25) are closed when the liquid level in the holding tank (20) is below a set value.
4. 4. The method of operation of a solar heat pump coupled multistage humidification and dehumidification water treatment system of claim 2, wherein the compressor (17) is a variable frequency compressor which is controlled by the temperature of the first temperature controller (30) together with the second three-way regulating valve (5), and the frequency of the compressor (17) and the opening of the outlet (d 1) of the second three-way regulating valve (5) are in inverse proportion regulation relationship with the temperature of the raw material liquid at the inlet (g 1) of the second humidifier (8).
5. 5. The method for operating a solar heat pump coupled multistage humidification and dehumidification water treatment system according to claim 2, wherein the flow regulating valve (23) is controlled by the temperature of the second temperature controller (31), the valve opening of the flow regulating valve (23) is in inverse proportion to the temperature of the cold humid air at the air outlet (j 1) of the evaporator (14), the first three-way regulating valve (3) is controlled by the flow of the flow controller (31), and the valve opening of the outlet (b 2) of the first three-way regulating valve (3) is controlled to set the flow flowing through the flow controller (31).

Description

Solar heat pump coupling type multistage humidifying and dehumidifying water treatment system and working method thereof Technical Field The invention belongs to the technical field of humidification and dehumidification water treatment, and relates to a multistage humidification and dehumidification water treatment system by coupling solar energy and a heat pump and a working method thereof. Background At present, the common sewage treatment technology, especially the sea water desalination technology, mainly comprises three types of low-temperature multi-effect distillation, multi-effect flash evaporation and reverse osmosis membranes, wherein the actual running cost is far higher than the design cost due to the unstable low-temperature waste heat, low efficiency and other reasons in the low-temperature multi-effect technology, and meanwhile, the equipment volume is larger and the device cost is higher. The multi-effect flash evaporation technology has the advantages of high operation temperature, easy corrosion and scaling, small operation elasticity, generally 80% -110% of design value, high initial investment cost of equipment, large initial construction engineering quantity, high energy consumption and need to be operated in combination with a thermal power plant. However, reverse osmosis has strict requirements on the water quality of the raw material liquid and has high pretreatment cost. And the reverse osmosis membrane is high in price, easy to pollute and damage in the use process, and generally needs to be updated once in 3-5 years. Considering the three common water treatment technologies comprehensively, the problems of initial running cost, strict requirements on raw material liquid, inapplicability to small-scale fresh water supply and the like exist. In remote islands, ships and other places, the required small-scale scattered fresh water requirement is usually met, the applicability of the three methods is low, meanwhile, the water treatment technology which is applied to more solar distillation methods in the past is difficult to widely use due to the problems of low heat efficiency, low water yield and the like, and the humidifying and dehumidifying water treatment technology which is rapidly developed in recent years has the advantages of flexible scale, small investment, suitability for the scattered water treatment requirement and the like, so that the best choice for solving the small-scale fresh water requirement is realized. The existing humidifying and dehumidifying water treatment technology has the defects that the heat source is concentrated in a solar heating mode, the heat source is easily influenced by weather conditions and cannot stably supply fresh water, a single-stage humidifying and dehumidifying system is adopted, the energy utilization rate is low, the fresh water yield is small, part of the system is heated by using electric heating as a heat source of a humidifying and dehumidifying system, the energy consumption is high, the fresh water production cost is high, and the heat pump system driven by electric energy can recover 3-5 parts of heat of the heat source for heating under the condition of low energy consumption by providing 1 part of electric energy for the heat pump system driven by electric energy. Therefore, there is a need to develop a technology capable of reducing the energy consumption of the humidification and dehumidification system to increase the yield, and considering the coupling of the solar heating technology and the heat pump system, the technology is energy-saving and environment-friendly, and meanwhile, the technology can stably supply the heat source required by the system, preferably can overcome the problem of low energy consumption of the single-stage system, and the multistage humidification and dehumidification system is utilized to increase the fresh water yield and reduce the energy consumption of the system. Disclosure of Invention The invention aims to solve the problems of unstable heat source supply, low efficiency of humidification and dehumidification processes, low water yield and the like in a humidification and dehumidification water treatment system, combines solar energy with a heat pump technology, and provides a two-stage solar heat pump coupling humidification and dehumidification water treatment system and a working method thereof. In order to achieve the above purpose, the invention adopts the following technical scheme: A solar heat pump coupled multi-stage humidification and dehumidification water treatment system comprises a water treatment circulation subsystem, a solar hot water circulation subsystem and a compression heat pump circulation subsystem, wherein the water treatment circulation subsystem comprises a first water pump 1, a dehumidifier 2, a first three-way regulating valve 3, a precooler 4, a second three-way regulating valve 5, a solution heat exchanger 6, a condenser 7, a second humidifier 8, a second