Solution concentration device for air source tower water source heat pump

Abstract

A solution concentration device for a water source heat pump of an air source tower comprises a condensation tank, a flash tank, a vacuumizing device and a water storage tank, the air source tower water source heat pump comprises a heat pump unit and a cooling tower; the flash tank is in pipeline connection with a water inlet and a water outlet of a condenser of the heat pump unit to form a warm water circulating pipeline; a low-temperature dilute solution outlet of the cooling tower is at least divided into two branches, one branch is connected with a heat exchange pipe of the condensation tank, and the other branch is connected with a heat exchange pipe of the heat pump unit evaporator; a steam outlet of the flash tank is connected with a steam inlet of the condensation tank through a pipeline; a high-temperature dilute solution outlet of the condensation tank is at least divided into two branches, one branch is connected with the cooling tower, and the other branch is connected with the flash tank; the vacuumizing device is used for sucking water in the condensation tank and conveying the water in the condensation tank to the water storage tank to be stored. According to the utility model, a system which can continuously and automatically operate and is low in energy consumption is formed, low-temperature solution concentration is realized, and safe operation of the air source tower in winter is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of heat pumps, in particular to a solution concentrating device for air source tower water source heat pumps. Background Art

[0002] Air-cooled heat pumps are energy-saving devices that recycle low-grade renewable energy - air heat. Especially in the context of dual carbon, they are the best solution to building and industrial heat. However, in the process of air-cooled heat pumps recovering air heat, there will be a frost problem, causing the heat exchanger channel to be blocked and unable to heat. At this time, the unit needs to be shut down for defrosting, and the defrosting energy consumption accounts for 10-30% of the total energy consumption. In addition, air-cooled heat pumps are greatly affected by air temperature during cooling in summer, and the cooling COP is much smaller than that of water-cooled chillers.

[0003] In recent years, air source tower (commonly known as energy tower or heat source tower) water source heat pump has gradually emerged. Air source tower water source heat pump is water-cooled in summer operation, and SCOP can reach above 4.6, which is 30% higher than air-cooled heat pump; in winter operation, cooling water is replaced with a low freezing point solution, and heat exchange is carried out with air in the cooling tower. After the air heat is recovered, the temperature is raised by the heat pump and then heat is supplied to the outside. Air source tower water source heat pump not only has high cooling efficiency in summer, but also solves the problem of frosting in winter operation. Although air source tower water source heat pump has many advantages, in actual use, because the water vapor in the air is absorbed by the solution, or rain and snow enter the tower, the concentration of the solution decreases, and the heat pump evaporator is prone to freezing pipe accidents, causing damage to the heat pump.

[0004] At present, the solutions used in the air source tower are mainly divided into two categories: inorganic solutions and organic solutions. Inorganic solutions are mainly aqueous solutions of calcium chloride or magnesium chloride, and organic solutions are mainly aqueous solutions of ethylene glycol or sodium acetate. Inorganic solution solutes are cheap and easy to obtain, but they contain a large amount of chloride ions, so they are highly corrosive and will cause corrosion perforation when entering the heat pump. Organic solutions are more expensive and less corrosive, but if there is no concentration method, the only method is to drain the dilute solution and then replenish the concentrated solution, which invisibly increases the operating cost of the system and pollutes the environment.

[0005] Common methods of concentrating the solution in the air source tower include thermal evaporation, electrodialysis, vacuum boiling and freezing regeneration. Among these methods, evaporation requires a lot of heat to heat the solution to boiling; electrodialysis requires a lot of electricity; freezing regeneration can only separate solid-liquid solutions and is not applicable to liquid-liquid concentration. Utility Model Content

[0006] The purpose of the utility model is to overcome the above-mentioned shortcomings of the prior art and provide a solution concentrating device for an air source tower water source heat pump which has low energy consumption and can realize stable operation.

[0007] The technical solution of the present utility model is: a solution concentration device for an air source tower water source heat pump, the concentration device comprising a condensation tank, a flash tank, a vacuum pumping device and a water storage tank; the air source tower water source heat pump comprising a heat pump unit and a cooling tower; the flash tank is respectively connected by pipelines between the water inlet and the water outlet of the condenser of the heat pump unit to form a warm water circulation pipeline; the low-temperature dilute solution outlet of the cooling tower is at least divided into two branches, one branch is connected to the heat exchange tube of the condensation tank, and the other branch is connected to the heat exchange tube of the evaporator of the heat pump unit; the steam outlet of the flash tank is connected to the steam inlet of the condensation tank through a pipeline; the high-temperature dilute solution outlet of the condensation tank is at least divided into two branches, one branch is connected to the cooling tower, and the other branch is connected to the flash tank; the vacuum pumping device is used for sucking the water in the condensation tank and transporting the water in the condensation tank to the water storage tank for storage.

[0008] Further, the high-temperature dilute solution outlet of the condensation tank is at least divided into two branches, one branch is connected to the cooling tower through valve F3, and the other branch is connected to the flash tank through valve F4.

[0009] Further, the low-temperature dilute solution outlet of the cooling tower is connected to the heat exchange tubes of the condensation tank and the evaporator respectively through a water pump, and a valve F1 is provided on the front side of the inlet of the heat exchange tube of the condensation tank to control the solution flow rate entering the condensation tank.

[0010] Further, the output end of the heat exchange tube of the evaporator is also connected to the cooling tower to form a cold water circulation pipeline between the evaporator and the cooling tower.

[0011] Further, the concentrated solution outlet of the flash tank is connected to the cooling tower or a solution storage container through valve F5.

[0012] Further, the vacuum pumping device includes a jet device and a water ring vacuum pump used in combination, and the jet device is provided on the front side of the inlet pipeline of the water ring vacuum pump; the water ring vacuum pump is used for continuously sucking the water in the condensation tank, and the jet device is used for introducing compressed air or other media to enhance the evacuation ability of the water ring vacuum pump.

[0013] Further, a drain port is provided at the bottom of the water storage tank, and a valve F2 is provided on the pipeline connected to the drain port.

[0014] Further, the water pump adopts a double water pump structure arranged in parallel.

[0015] Further, a liquid level detection sensor is provided in the water storage tank to detect whether the water in the water storage tank reaches the target liquid level, and if so, valve F2 is opened.

[0016] Advantages of the utility model: By connecting the pipelines of each device to form a system that can operate continuously and automatically with low energy consumption and applying it to the solution concentration device in the air source tower, low-temperature solution concentration is achieved by the method of vacuum flashing, and the concentrated heat source returns to the system with almost no loss. This device provides guarantee for the safe operation of the air source tower in winter. Brief Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of an embodiment of the utility model.

[0018] Description of the reference numerals in the drawings:

[0019] 1. Cooling tower; 2. Evaporator; 3. Condenser; 4. Water storage tank; 5. Injection device; 6. Liquid ring vacuum pump; 7. Condensation tank; 8. Flash tank; 9. Water pump. Detailed Embodiment

[0020] The following will further describe the utility model in detail with reference to the drawings of the specification and specific embodiments.

[0021] As Figure 1 shown: A solution concentration device for an air source tower water source heat pump includes a condensation tank 7, a flash tank 8, an injection device 5, a liquid ring vacuum pump 6 and a water storage tank 4; the air source tower water source heat pump includes a heat pump unit and a cooling tower 1; the flash tank 8 is respectively connected by pipelines between the water inlet and the water outlet of the condenser 3 of the heat pump unit to form a warm water circulation pipeline; the low-temperature dilute solution outlet of the cooling tower 1 is divided into two branches, one branch is connected to the heat exchange tube of the condensation tank 7, and the other branch is connected to the heat exchange tube of the evaporator 2; the steam outlet of the flash tank 8 is connected to the steam inlet of the condensation tank 7 through a pipeline; the high-temperature dilute solution outlet of the condensation tank 7 is divided into two branches, one branch is connected to the cooling tower 1 through a valve F3, and the other branch is connected to the flash tank 8 through a valve F4.

[0022] The above solution has the following advantages: (1) By combining the heat pump unit with the flash tank, the warm water generated by the condenser of the heat pump unit is directly used to heat the high-temperature dilute solution in the flash tank to promote its boiling and generate steam. This design utilizes the efficient energy conversion characteristics of the heat pump unit to achieve effective recovery and utilization of energy and reduce energy waste; (2) The low-temperature dilute solution transported by the cooling tower is divided into two branches, part of which passes through the heat exchange tube of the condensation tank, and the other part passes through the heat exchange tube of the evaporator of the heat pump unit. This design not only utilizes the low-temperature dilute solution generated by the cooling tower, but also effectively utilizes the remaining heat, improving the overall energy utilization efficiency; (3) By connecting the condensation tank and the flash tank with relevant pipelines, the recovery and reuse of energy are realized, effectively reducing the energy consumption of the system and promoting solution concentration.

[0023] In this embodiment, the low-temperature dilute solution outlet of the cooling tower 1 is connected to the heat exchange tubes of the condensation tank 7 and the evaporator 2 respectively through the water pump 9, and a valve F1 is provided on the front side of the heat exchange tube inlet of the condensation tank 7 to control the solution flow rate into the condensation tank 7. Among them, the water pump 9 is preferably arranged in parallel with two water pumps. The output end of the heat exchange tube of the evaporator 2 is connected to the cooling tower 1 to form a cold water circulation pipeline.

[0024] In this embodiment, the valve F4 is preferably an electric valve, which is used to control the flow rate and flashing speed of the high-temperature dilute solution entering the flash tank 8. The concentrated solution outlet of the flash tank 8 is connected to the cooling tower 1 or the solution storage container through the valve F5.

[0025] In this embodiment, the water outlet of the condensation tank 7 is connected to the water storage tank 4 through the water ring vacuum pump 6 and the injection device 5. Among them, the injection device 5 is used in combination with the water ring vacuum pump 6, and the injection device 5 is arranged on the front side of the inlet pipeline of the water ring vacuum pump 6. The water ring vacuum pump 6 is used to continuously suck the water in the condensation tank 7. The injection device 5 enhances the evacuation ability of the water ring vacuum pump 6 by introducing compressed air or other media, thereby increasing the vacuum, so that an extremely low pressure is formed in the condensation tank 7 and the flash tank 8, and then the boiling temperature of the solution in the flash tank 8 drops, and the water in the condensation tank 7 enters the water storage tank 4 for storage under the action of the water ring vacuum pump 6; a drain port is provided at the bottom of the water storage tank 4, and a valve F2 is provided on the pipeline connected to the drain port. It can be said that the heat energy exchange process between the flash tank and the condensation tank in this embodiment maintains a suitable pressure environment through the water ring vacuum pump, effectively ensuring the stable operation of the system.

[0026] The working principle of this embodiment is as follows: Open the valves F1 and F3 - F5. The low-temperature dilute solution of the cooling tower 1 is pumped into the evaporator 2 of the heat pump unit and the condensation tank 7 of the concentration device through the water pump 9 and enters the respective heat exchange tubes; the low-temperature dilute solution in the heat exchange tube of the condensation tank exchanges heat with the high-temperature water vapor transported from the flash tank 8, condensing the high-temperature water vapor into pure water, and the low-temperature dilute solution absorbs heat and rises to a high-temperature dilute solution. Under the open state of the valve F3 and the valve F4, a part enters the flash tank 8, and the other part returns to the cooling tower 1. The warm water generated by the condenser 3 of the heat pump unit enters the flash tank 8, heating the high-temperature dilute solution in the flash tank 8 until the solution boils to produce concentrated solution and water vapor; the concentrated solution is stored through the valve F5 or returns to the cooling tower 1 again; the water vapor generated by the flash tank 8 enters the condensation tank 7 and condenses into water, and then is connected to the water ring vacuum pump 6 through a pipeline. The water ring vacuum pump 6 generates negative pressure through continuous circulation, continuously sucking the water in the condensation tank 7, and forming an extremely low pressure in the condensation tank 7 and the flash tank 8, so that the boiling temperature of the solution in the flash tank 8 drops. The water in the condensation tank 7 is finally stored in the water storage tank 4 through the water ring vacuum pump 6. When the water in the water storage tank 4 reaches a certain amount, the valve F2 is opened for discharge. After the work is completed, close the valves F1 and F3 - F5 to stop the unit operation.

[0027] The main features of the concentration device of this embodiment are: the heat of the heated solution in the flash tank 8 mainly comes from two parts, one part comes from the high-temperature dilute solution obtained by heating the low-temperature dilute solution with water vapor in the condenser tank 7, and the other part is heated by the warm water in the condenser 3 of the heat pump unit; since the heating efficiency of the heat pump unit can reach more than 3.6, the actual power consumed by flash evaporation is very small. In addition, a water ring vacuum pump 6 is used to maintain extremely low pressure in the condenser tank 7 and the flash tank 8 to reduce the boiling pressure of water vapor, and the condenser tank 7 uses a low-temperature dilute solution to reduce the condensation pressure, ensuring that the dilute solution in the flash tank can boil at around 30°C.

[0028] In summary, the utility model is a solution concentration device used in an air source tower which can operate continuously and automatically with low energy consumption. It adopts the vacuum flash evaporation method to achieve the concentration of low-temperature solution, and the concentrated heat source returns to the system with almost no loss. This device provides a guarantee for the safe operation of the air source tower in winter.

Claims

1. A solution concentration device for an air source tower water source heat pump, characterized in that: The concentrating device includes a condensing tank, a flash tank, a vacuum pump and a water storage tank; the air source tower water source heat pump includes a heat pump unit and a cooling tower; the flash tank is respectively connected to the water inlet and the water outlet of the heat pump unit condenser through pipelines to form a warm water circulation pipeline; the low-temperature dilute solution outlet of the cooling tower is divided into at least two branches, one branch is connected to the heat exchange pipe of the condensing tank, and the other branch is connected to the heat exchange pipe of the evaporator of the heat pump unit; the steam outlet of the flash tank is connected to the steam inlet of the condensing tank through a pipeline; the high-temperature dilute solution outlet of the condensing tank is divided into at least two branches, one branch is connected to the cooling tower, and the other branch is connected to the flash tank; the vacuum pump is used to suck the water in the condensing tank and transport the water in the condensing tank to the water storage tank for storage.

2. The solution concentrating device for air source tower water source heat pump according to claim 1, characterized in that: The high-temperature dilute solution outlet of the condensation tank is divided into at least two branches, one branch is connected to the cooling tower via valve F3, and the other branch is connected to the flash tank via valve F4.

3. The solution concentrating device for air source tower water source heat pump according to claim 1, characterized in that: The low-temperature dilute solution outlet of the cooling tower is connected to the heat exchange pipes of the condenser and the evaporator through a water pump, and a valve F1 is provided on the front side of the heat exchange pipe inlet of the condenser to control the solution flow entering the condenser.

4. The solution concentrating device for air source tower water source heat pump according to claim 3, characterized in that: The output end of the heat exchange tube of the evaporator is connected to a cooling tower, and a cold water circulation pipeline is formed between the cooling tower and the heat exchange tube.

5. The solution concentrating device for air source tower water source heat pump according to claim 1, characterized in that: The concentrated solution outlet of the flash tank is connected to a cooling tower or a solution storage container through a pipeline via a valve F5.

6. The solution concentrating device for air source tower water source heat pump according to claim 1, characterized in that: The vacuum device comprises an ejector device and a water ring vacuum pump used in conjunction with each other. The ejector device is arranged at the front side of the inlet pipe of the water ring vacuum pump. The water ring vacuum pump is used to continuously suck water in the condensation tank, and the ejector device is used to introduce compressed air to enhance the vacuuming capacity of the water ring vacuum pump.

7. The solution concentrating device for air source tower water source heat pump according to claim 1, characterized in that: A drain outlet is provided at the bottom of the water storage tank, and a valve F2 is provided on the pipeline connected to the drain outlet.

8. The solution concentrating device for air source tower water source heat pump according to claim 3, characterized in that: The water pump adopts a double water pump structure arranged in parallel.

9. The solution concentrating device for air source tower water source heat pump according to claim 7, characterized in that: A liquid level detection sensor is provided in the water tank for detecting whether the water in the water tank has reached the target liquid level. If so, the valve F2 is opened.

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