CN109019733A - Single packed tower humidification heat pump solution concentration systems and method - Google Patents

Abstract

A single-packed tower humidification heat pump solution concentration system and method belong to the field of energy saving. The system includes condenser (2), seawater pump (3), packed tower (7), fan (9), heat exchanger (10), gas-liquid separator (11), fresh water tank (13), circulating water pump ( 14), evaporator (15), compressor (17), throttle valve (19). The system uses the heat released by the condenser (2) to heat the total seawater (1); uses the cooling capacity of the evaporator (15) to condense the high-temperature air (6), which improves the thermal efficiency of the system cycle; The humidification and dehumidification processes occur in the tower (7) and the heat exchanger (10), respectively. This process has the advantages of flexible scale, moderate equipment investment and operating costs, low-level heat energy can be used, low technical level requirements, and equipment miniaturization, etc., so The system is more energy efficient than conventional systems.

Description

Single packed tower humidification heat pump solution concentration system and method

technical field

The invention relates to a single-packed tower humidification heat pump solution concentration system and method, and belongs to the field of energy conservation.

technical background

With the shortage of fresh water resources, seawater desalination technology has been paid more and more attention by various countries. At present, many countries have taken seawater desalination as a key technology to solve the problem of fresh water shortage.

Seawater desalination is the process of separating the salt and water in seawater, and finally obtain fresh water and concentrated brine. The main traditional seawater desalination methods include reverse osmosis and distillation. Among them, the reverse osmosis method refers to the process of applying an external pressure higher than the osmotic pressure of the solution on the raw water side of the membrane. When the raw water passes through the semi-permeable membrane, only water is allowed to pass through, and other substances cannot pass through and are trapped on the surface of the membrane. However, in the reverse osmosis method, seawater pretreatment is strictly required, and the utilization rate of raw water is only 75-80%. In addition, high-pressure equipment is required, and the membrane needs to be cleaned regularly, and the cleaning cost is relatively high. Distillation is often used to separate and purify liquid mixtures, but traditional distillation has problems such as high energy consumption, low economic benefits, complex device structure, difficult operation, and low heat exchange efficiency.

Humidification and dehumidification seawater desalination method is currently a research hotspot. Its principle is to evaporate seawater into water vapor, and then condense pure fresh water. It has flexible scale, moderate equipment investment and operation cost, low heat energy can be used, low technical level requirements, and the device is convenient. Miniaturized, this technology is considered to be the most promising method in seawater desalination.

Heat pump systems have been widely used in industry due to their advantages such as high COP and high efficiency. And the system is environmentally friendly and safe, there is no combustion process, and smoke pollution is avoided.

Contents of the invention

The purpose of the present invention is to integrate the heat pump system and the humidification, dehumidification and desalination method, and propose a single-packed tower that utilizes the difference in humidification capacity of the air at different temperatures, uses the packed tower for direct contact heat and mass transfer, and reduces energy consumption Humidification heat pump solution concentration system and method.

The system includes condenser, seawater pump, packed tower, fan, heat exchanger, gas-liquid separator, fresh water tank, circulating water pump, evaporator, compressor, and throttle valve. Condenser includes hot side inlet, hot side outlet, cold side inlet and cold side outlet; evaporator includes hot side inlet, hot side outlet, cold side inlet and cold side outlet; packed tower includes total seawater inlet, concentrated seawater outlet, low temperature Air inlet and high temperature air outlet; heat exchanger includes hot side inlet, hot side outlet, cold side inlet, cold side outlet; gas-liquid separator includes upper inlet, lower outlet, gas outlet; condenser hot side outlet passes throttling valve It is connected to the inlet of the cold side of the evaporator, the outlet of the cold side of the evaporator is connected to the inlet of the compressor, and the outlet of the compressor is connected to the inlet of the hot side of the condenser. The concentrated seawater outlet is mixed with new seawater and connected to the inlet of the seawater pump, the outlet of the seawater pump is connected to the cold side inlet of the condenser, the high temperature air outlet of the packed tower is connected to the hot side inlet of the heat exchanger, and the hot side outlet of the heat exchanger is connected to the gas-liquid The upper inlet of the separator is connected, the gas outlet of the gas-liquid separator is connected with the low-temperature air inlet of the packed tower through the air pump, and its liquid outlet is connected with the fresh water tank; the cold side outlet of the heat exchanger is connected with the hot side inlet of the evaporator through a circulating water pump, and the evaporation The outlet on the hot side of the heat exchanger is connected to the inlet on the cold side of the heat exchanger;

The single-packed tower humidification heat pump solution concentration system and method is characterized in that it includes the following process: after the refrigerant is pressurized by the compressor, it enters the hot end from the hot side inlet of the condenser, and transfers heat to the seawater at the cold end, The cooled refrigerant flows into the throttling valve for throttling, and then enters the cold end through the cold side inlet of the evaporator, exchanges heat with the cold water at the hot end, cools the cold water at the hot end, and then circulates into the compressor; fresh seawater and concentrated seawater Mixed into the total seawater, the total seawater is pressurized by the seawater pump, enters the cold end from the cold side inlet of the condenser, and exchanges heat with the refrigerant at the hot end, the total seawater absorbs heat and heats up, and then enters the packing through the total seawater inlet of the packed tower Tower; low-temperature air enters the packed tower from the low-temperature air inlet, and the low-temperature air is mixed with the total seawater. Due to the hygroscopicity of the low-temperature air, the total seawater undergoes a hygroscopic reaction, and the total seawater is concentrated to obtain concentrated seawater. The concentrated seawater is passed into the seawater pump to be circulated Utilization; when the amount of seawater is insufficient, new seawater is introduced to ensure the normal operation of the system; the low-temperature air becomes high-temperature air containing water vapor, and the high-temperature air flows out from the high-temperature air outlet of the packed tower, and enters it from the hot side inlet of the heat exchanger The hot end exchanges heat with the cold water at the cold end, the high-temperature air is cooled, and moisture is condensed, and the mixture of air and liquid water enters the gas-liquid separator through the upper inlet of the gas-liquid separator, and is separated into two parts, namely, low-temperature air and Fresh water and low-temperature air flow out from the gas outlet of the gas-liquid separator. After being pressurized by the fan, they enter the packed tower from the low-temperature air inlet of the packed tower again, and reciprocate; fresh water flows out from the lower outlet of the gas-liquid separator and enters the fresh water tank for storage; The cold water enters the hot side from the hot side inlet of the evaporator, exchanges heat with the refrigerant on the cold side, absorbs the cooling capacity of the cold side, lowers the temperature, then flows out from the hot side outlet, and enters through the cold side inlet of the heat exchanger Its cold end transfers cold energy to the high-temperature air on its hot side, making it condense into fresh water, and then the cold water flows out from the outlet of its cold side and enters the circulating water pump, so that the cycle reciprocates;

For this system, the seawater uses the heat released by the condenser to absorb heat and heat up, and the cold water uses the cooling capacity of the evaporator to condense the high-temperature air in the heat exchanger to obtain fresh water, which improves the thermal efficiency of the overall system; in addition, for air, It absorbs the moisture of seawater in the packed tower and undergoes a hygroscopic reaction, and then condenses in the heat exchanger to obtain fresh water and undergoes a dehumidification reaction. The process can obtain fresh water, and the system scale is flexible, the equipment investment and operating costs are moderate, and the device is small , saving costs.

Description of drawings

Fig. 1 The single-packed tower humidification heat pump solution concentration system and method.

Label names in the figure: 1. Total seawater, 2. Condenser, 3. Seawater pump, 4. New seawater, 5. Concentrated seawater, 6. High temperature air, 7. Packed tower, 8. Low temperature air, 9. Fan, 10 , heat exchanger, 11, gas-liquid separator, 12, fresh water, 13, fresh water tank, 14, circulating water pump, 15, evaporator, 16, cold water, 17, compressor, 18, refrigerant, 19, throttle valve .

Specific implementation method

The operation process of the single-packed tower humidification heat pump solution concentration system is described below with reference to accompanying drawing 1:

Start the circulating water pump 14, the cold water 16 enters the hot side of the evaporator 15, exchanges heat with the refrigerant 18 on the cold side, absorbs the cooling capacity of the cold side, then flows out from the outlet of the hot side, and enters the cold end of the heat exchanger 10, The cold energy is transferred to the high-temperature air 6 on the hot side, making it condense into fresh water 12, which then flows out from the outlet on the cold side and enters the circulating water pump 14, so that the cycle reciprocates.

Start the seawater pump 3, the new seawater 4 and the concentrated seawater 5 are mixed into the total seawater 1, the total seawater 1 is pressurized by the seawater pump 3, enters the cold end of the condenser 2, and exchanges heat with the refrigerant 18 at the hot end, the total seawater 1 absorbs Heat up, then enter the packed tower 7, and mix with the low-temperature air 8. Due to the hygroscopicity of the low-temperature air 8, the water is absorbed, and the total seawater 1 is concentrated to obtain concentrated seawater 5, which is passed into the seawater pump 3 for recycling; When the amount of seawater is insufficient, new seawater 4 is introduced to ensure the normal operation of the system.

Start the fan 9, as above, the low-temperature air 8 enters the packed tower 7, and dehumidifies the total seawater 1, and it becomes the high-temperature air 6, and the high-temperature air 6 flows out from the high-temperature air outlet of the packed tower 7, and enters the heat exchanger 10. The hot end exchanges heat with the cold water 16 at the cold end, the temperature drops, and moisture is condensed, and the mixture of air and liquid water enters the gas-liquid separator 11 for gas-liquid separation, and two parts are separated, namely low-temperature air 8 and fresh water 12, The low-temperature air 8 flows out from the gas outlet of the gas-liquid separator 11, and after being pressurized by the fan 9, it enters the packed tower 7 from the dry air inlet of the packed tower 7 again, and reciprocates; the fresh water 12 flows out from the lower outlet of the gas-liquid separator 11, Enter the fresh water tank 13 for storage.

Finally, the compressor 17 is started, and the refrigerant 18 enters the hot end of the condenser 2 after being pressurized by the compressor 17, and transfers heat to the seawater at the cold end, and the cooled refrigerant 18 is then passed into the throttling valve 19 to throttle and enter The cold end of the evaporator 15 exchanges heat with the cold water 16 at the hot end, cools the cold water 16 at the hot end, and then enters the compressor 4 through the compressor 4 inlet, and thus reciprocates;

When the system operation is finished, the compressor 17, the blower fan 9, the seawater pump 3 and the circulating water pump 14 are closed in sequence, and the system stops running.

Claims (2)

1. A single packed tower humidification heat pump solution concentration system, characterized in that: The system includes condenser (2), seawater pump (3), packed tower (7), fan (9), heat exchanger (10), gas-liquid separator (11), fresh water tank (13), circulating water pump ( 14); Evaporator (15), compressor (17), throttle valve (19); The condenser (2) includes a hot side inlet, a hot side outlet, a cold side inlet and a cold side outlet; The evaporator (15) includes a hot side inlet, a hot side outlet, a cold side inlet and a cold side outlet; The packed tower (7) includes a total seawater inlet, a concentrated seawater outlet, a low-temperature air inlet and a high-temperature air outlet; The heat exchanger (10) includes a hot side inlet, a hot side outlet, a cold side inlet, and a cold side outlet; The gas-liquid separator (11) includes an upper inlet, a lower outlet, and a gas outlet; The outlet of the hot side of the condenser (2) is connected to the inlet of the cold side of the evaporator (15) through the throttle valve (19), the outlet of the cold side of the evaporator (15) is connected to the inlet of the compressor (17), and the outlet of the compressor (17) is connected to the inlet of the compressor (17). The inlet of the hot side of the condenser (2) is connected to each other, so that the cycle reciprocates; The cold side outlet of the condenser (2) is connected to the total seawater inlet of the packed tower (7), and the concentrated seawater outlet of the packed tower (7) is mixed with fresh seawater (4) and connected to the seawater pump (3) inlet, and the seawater pump (3) The outlet is connected to the cold side inlet of the condenser (2), The high-temperature air outlet of the packed tower (7) is connected to the hot side inlet of the heat exchanger (10), and the hot side outlet of the heat exchanger (10) is connected to the upper inlet of the gas-liquid separator (11), and the gas-liquid separator (11) The gas outlet is connected to the low-temperature air inlet of the packed tower (7) through the air pump (9), and its liquid outlet is connected to the fresh water tank (13); The cold side outlet of the heat exchanger (10) is connected with the hot side inlet of the evaporator (15) through the circulating water pump (14), and the hot side outlet of the evaporator (15) is connected with the cold side inlet of the heat exchanger (10). 2. The method of the single-packed tower humidification heat pump solution concentration system according to claim 1, characterized in that it comprises the following process: After the refrigerant (18) is pressurized by the compressor (17), it enters the hot end from the hot side inlet of the condenser (2), and transfers heat to the seawater at the cold end, and the cooled refrigerant (18) flows into the throttling The valve (19) is throttling, enters the cold end through the cold side inlet of the evaporator (15), exchanges heat with the cold water (16) at the hot end, cools the cold water (16) at the hot end, and then circulates into the compressor (17); Fresh seawater (4) and concentrated seawater (5) are mixed into total seawater (1). After being pressurized by the seawater pump (3), the total seawater (1) enters the cold end of the condenser (2) from the cold side inlet, and is heated Refrigerant (18) at the end of the heat exchange, the total seawater (1) absorbs heat and heats up, and then enters the packed tower (7) through the total seawater inlet of the packed tower (7); The low-temperature air (8) enters the packed tower (7) from the low-temperature air inlet, and the low-temperature air (8) is mixed with the total seawater (1). Due to the hygroscopicity of the low-temperature air (8), the total seawater (1) undergoes a hygroscopic reaction. The total seawater (1) is concentrated to obtain concentrated seawater (5), and the concentrated seawater (5) is passed into the seawater pump (3) to be recycled; when the amount of seawater is insufficient, new seawater (4) is passed into to ensure the normal operation of the system; low temperature The air (8) turns into high-temperature air (6) containing water vapor, and the high-temperature air (6) flows out from the high-temperature air outlet of the packed tower (7), and enters the hot end from the hot side inlet of the heat exchanger (10). The cold water (16) at the cold end performs heat exchange, and the high-temperature air (6) is condensed to obtain moisture. The mixture of air and liquid water enters the gas-liquid separator (11) through the upper inlet of the gas-liquid separator (11), and is separated into two The parts are low-temperature air (8) and fresh water (12), respectively. The low-temperature air (8) flows out from the gas outlet of the gas-liquid separator (11), and after being pressurized by the fan (9), it is re-flowed from the packed tower (7). The air inlet enters the packed tower (7) and reciprocates; the fresh water (12) flows out from the lower outlet of the gas-liquid separator (11) and enters the fresh water tank (13) for storage; The cold water (16) enters the hot side of the evaporator (15) from the hot side inlet, exchanges heat with the refrigerant (18) on the cold side, absorbs the cooling energy of the cold side, and then flows out from the outlet of the hot side, after heat exchange The inlet of the cold side of the device (10) enters its cold end, and transfers the cold energy to the high-temperature air (8) on its hot side, causing it to condense out of fresh water (12), and then the cold water (16) flows out from its outlet on the cold side and enters Circulating water pump (14), so reciprocating circulation.