A heat source tower solution concentration system and method based on a plate air heat exchanger common loop

Abstract

This application discloses a solution concentration system and method based on a common loop heat source tower using a plate air heat exchanger, relating to the field of solution concentration. The system includes: a solution tank connected to an atomizing unit via a solution pump; a first duct housing a fan, whose outlet is connected to the heat absorption side inlet of the plate air heat exchanger, and whose solution return outlet is connected to the solution tank inlet, used to receive the concentrated solution after the initial concentration. The heat absorption side outlet of the heat exchanger is connected to the inlet of a second duct, and the outlet of the second duct is connected to a heating unit for secondary solution concentration. The heating unit is connected to the heat release side inlet of the heat exchanger via a third duct. The heat release side outlet of the heat exchanger is connected to the inlet of a fourth duct, and the outlet of the fourth duct is connected to the outside, with its outlet connected to a condensate tank. This application enables thorough gas-liquid mixing, improves solution concentration efficiency through two concentration cycles, and reduces concentration energy consumption and costs through the common loop of the plate air heat exchanger.

Description

Technical Field

[0001] This application relates to the field of solution concentration, and in particular to a heat source tower solution concentration system and method based on a plate air heat exchanger common loop. Background Technology

[0002] Traditional air-source heat pump systems are susceptible to frost formation in low-temperature, high-humidity environments, leading to reduced energy efficiency. Heat source tower heat pump technology utilizes a solution to absorb moisture from the ambient air, preventing frost formation on the outdoor heat exchanger and increasing the heat extraction efficiency from the outdoor air, making it widely used in high-humidity winter regions. However, with increased operating time, the concentration of the solution gradually decreases after absorbing moisture from the air, resulting in a corresponding reduction in its moisture absorption capacity. This not only reduces the overall concentration efficiency but also causes solution condensation due to the increased freezing point, impacting the energy efficiency of the heat source tower heat pump.

[0003] Therefore, solution regeneration and concentration devices have become a key research direction in the field of heat source tower heat pumps. Through solution regeneration and concentration, not only can the hygroscopic capacity of the solution be effectively restored, but its freezing point can also be prevented from rising, ensuring normal operation in low-temperature and high-humidity environments. Research and optimization of solution regeneration and concentration technology not only help improve the energy efficiency of heat source tower heat pump systems in low-temperature and high-humidity environments, but also extend the service life of the equipment and reduce maintenance costs caused by solution solidification.

[0004] Currently, heat source tower solution concentration typically employs the following two methods: 1) Adding new, high-concentration solution and solute to a diluted solution while simultaneously releasing low-concentration diluted solution into the environment. This method pollutes the environment and results in high solution loss and material costs. 2) Heat the solution or circulating air using heat pumps, electricity, steam, industrial waste heat, or other heat sources to achieve solution concentration through heat and mass transfer between the solution and the air. For example, a heat pump condenser can be used as a heater to heat the solution or circulating air, promoting water evaporation, and a heat pump evaporator can be used to recover the heating heat. However, this method has problems such as incomplete heat recovery, high driving energy consumption, and complex equipment. Summary of the Invention

[0005] The purpose of this application is to provide a heat source tower solution concentration system and method based on a plate air heat exchanger common loop, which can fully mix gas and liquid, improve solution concentration efficiency by using two concentrations, and reduce concentration energy consumption and cost by using a plate air heat exchanger common loop.

[0006] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a heat source tower solution concentration system based on a plate air heat exchanger with a common loop. The system includes: a solution tank, a solution pump, a multi-nozzle atomizing unit, a fan, a first duct, a second duct, a third duct, a fourth duct, a plate air heat exchanger, a filter unit, a heating unit, and a condensate tank. The outlet of the solution tank is connected to the solution pump pipeline. The solution pump passes through the pipe wall on the outlet side of the first duct and is connected to the multi-nozzle atomizing unit pipeline. The multi-nozzle atomizing unit is used to atomize the initial solution in the solution tank to generate an atomized solution. The fan is provided on the inlet side of the first duct, the outlet of the first duct is connected to the heat absorption side inlet of the plate air heat exchanger, and the solution return port of the first duct is connected to the inlet pipeline of the solution tank. The plate air heat exchanger is used to heat and evaporate the gas-liquid mixture formed by the atomized solution and air. The first duct concentrates the water content; the inlet of the second duct is connected to the heat absorption side outlet of the plate air heat exchanger, and the outlet of the second duct is connected to the heating unit; the filter unit is installed inside the second duct; the filter unit is used to filter the residual solution in the air, and after the water content in the residual solution in the second duct evaporates further to unsaturated air, a second concentration is completed; the inlet of the third duct is connected to the heating unit, and the outlet of the third duct is connected to the heat release side inlet of the plate air heat exchanger; the inlet of the fourth duct is connected to the heat release side outlet of the plate air heat exchanger, the outlet of the fourth duct is connected to external air, and the condensate outlet of the fourth duct is connected to the inlet of the condensate tank; the first duct, the second duct, and the fourth duct are all provided with return grooves on their pipe walls.

[0007] Secondly, this application also provides a method for concentrating a heat source tower solution based on a common loop of a plate air heat exchanger. This method is applied to the aforementioned heat source tower solution concentration system based on a common loop of a plate air heat exchanger. The method includes: when the concentration process begins, a solution pump pumps the solution to be concentrated from the solution tank to a multi-nozzle atomizing unit for atomization, generating an atomized solution; a fan delivers air in a first duct, mixing the atomized solution with air to form a gas-liquid mixture, which is then transported to the plate air heat exchanger; the plate air heat exchanger performs heat exchange on the gas-liquid mixture, evaporating some of the water in the atomized solution into water vapor; the concentrated solution obtained from water evaporation flows back to the solution tank through the return groove of the first duct, completing the first concentration; a filter unit in a second duct filters the residual solution, preventing the solution from flowing into the heating unit, obtaining a residual concentrated solution, which is then discharged under the air supply of the fan. The solution adheres to the wall of the second duct, and after the moisture in the residual solution in the second duct evaporates further to unsaturated air, the secondary concentration is completed. The heating unit raises the air temperature in the third duct to obtain high-temperature and high-humidity air. The plate air heat exchanger exchanges heat with the high-temperature and high-humidity air, releasing the sensible and latent heat of the high-temperature and high-humidity air, and the condensate obtained after condensation flows back to the condensate tank through the return groove of the fourth duct. The heat exchange process of the plate air heat exchanger uses the gas-liquid mixture as the heat absorption side and the high-temperature and high-humidity air as the heat release side, and the gas-liquid mixture absorbs heat and the high-temperature and high-humidity air releases heat simultaneously through a complete heat exchange loop. When the concentration process ends, the fan is turned off, the return groove of the second duct guides the residual concentrated solution suspended in the second duct to the first duct, and the return groove of the first duct guides the residual concentrated solution to the solution tank. After the concentrated solution is collected, the secondary concentration is completed.

[0008] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application includes a solution tank, a solution pump, a multi-nozzle atomizing unit, a fan, a first air duct, a second air duct, a third air duct, a fourth air duct, a plate air heat exchanger, a filter unit, a heating unit, and a condensate tank. The solution tank is connected to the atomizing unit via the solution pump. The first air duct houses the fan, whose outlet is connected to the heat-absorbing side inlet of the plate air heat exchanger, and its solution return outlet is connected to the solution tank inlet, used to receive the concentrated solution after the initial concentration. The heat-absorbing side outlet of the heat exchanger is connected to the inlet of the second air duct, and the outlet of the second air duct is connected to the heating unit for secondary solution concentration. The heating unit is connected to the heat-releasing side inlet of the heat exchanger via the third air duct. The heat-releasing side outlet of the heat exchanger is connected to the inlet of the fourth air duct, and the outlet of the fourth air duct is connected to the outside environment, with its outlet connected to the condensate tank. In summary, this application enables thorough gas-liquid mixing, improves solution concentration efficiency through two concentration cycles, and reduces concentration energy consumption and costs through the common loop of the plate air heat exchanger. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the structure of a heat source tower solution concentration system based on a plate air heat exchanger common loop, provided in an embodiment of this application.

[0011] Figure 2 This is a schematic flowchart of a heat source tower solution concentration method based on a common loop plate air heat exchanger, provided in an embodiment of this application.

[0012] Figure label: 1. Solution tank; 2. Solution pump; 3. Multi-nozzle atomizing unit; 4. Fan; 5. First air duct; 6. Second air duct; 7. Third air duct; 8. Fourth air duct; 9. Plate air heat exchanger; 10. Filter unit; 11. Heating unit; 12. Condensate tank; 13. First valve; 14. Second valve; 15. Control module; 16. First temperature and humidity sensor; 17. Second temperature and humidity sensor; 18. Concentration monitoring device. Detailed Implementation

[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0014] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] Example 1, such as Figure 1 As shown, this embodiment provides a heat source tower solution concentration system based on a plate air heat exchanger common loop. The system includes: a solution tank 1, a solution pump 2, a multi-nozzle atomizing unit 3, a fan 4, a first air duct 5, a second air duct 6, a third air duct 7, a fourth air duct 8, a plate air heat exchanger 9, a filter unit 10, a heating unit 11, and a condensate tank 12.

[0016] The outlet of solution tank 1 is connected to the pipeline of solution pump 2.

[0017] Optionally, a concentration monitoring device 18 is installed in the solution tank 1 to monitor the solution concentration.

[0018] Optionally, the inlet of solution tank 1 is located above solution tank 1, and the outlet of solution tank 1 is located below solution tank 1.

[0019] Solution pump 2 passes through the pipe wall on the air outlet side of the first air duct 5 and is connected to the multi-nozzle atomizing unit 3; the multi-nozzle atomizing unit 3 is used to atomize the initial solution in solution tank 1 to produce atomized solution.

[0020] Furthermore, the multi-nozzle atomizing unit 3 includes: multiple high-pressure atomizing nozzles.

[0021] Furthermore, each of the high-pressure atomizing nozzles is equipped with an independent on / off valve.

[0022] Optionally, the switching valve is a butterfly valve, used to control the flow rate of the solution in order to achieve precise control of each process node.

[0023] Furthermore, multiple high-pressure atomizing nozzles are arranged at equal intervals along the first air duct 5.

[0024] In practical applications, the arrangement of multiple high-pressure atomizing nozzles can expand the gas-liquid interface, thereby improving the heat and mass transfer effect.

[0025] A fan 4 is installed on the air inlet side of the first air duct 5. The air outlet of the first air duct 5 is connected to the heat absorption side air inlet of the plate air heat exchanger 9. The solution return port of the first air duct 5 is connected to the liquid inlet pipe of the solution tank 1. The plate air heat exchanger 9 is used to complete the first concentration by heating and evaporating the water in the gas-liquid mixture formed by the atomized solution and air.

[0026] Optionally, the heat exchange process of the first concentration causes the water in the atomized solution to absorb the heat of the heated air, thereby causing the water in the atomized solution to evaporate. This gradually increases the concentration of the solution in the droplets carried by the air. As the solution gradually becomes more concentrated, under the influence of gravity, the concentrated solution (the first concentrated solution) eventually falls into the groove of the first air duct 5 and flows into the solution tank 1, completing one concentration process.

[0027] The air inlet of the second air duct 6 is connected to the heat absorption side air outlet of the plate air heat exchanger 9, and the air outlet of the second air duct 6 is connected to the heating unit 11. The filter unit 10 is installed inside the second air duct 6. The filter unit 10 is used to filter the residual solution in the air. After the water in the residual solution in the second air duct 6 is further evaporated to unsaturated air, the secondary concentration is completed.

[0028] Optionally, a first temperature and humidity sensor 16 is installed inside the second air duct 6 to monitor the temperature inside the second air duct 6.

[0029] Furthermore, the filtration device is a baffle plate.

[0030] Optionally, the filter can prevent tiny droplets containing solution from entering the heating unit 11, allowing only air to pass through, in order to avoid corrosive damage to the heater.

[0031] In practical applications, the plate air heat exchanger 9 can perform deep heat recovery of the sensible heat of the heated air side and the latent heat released by the condensation of water vapor, and directly drive the concentration of the atomized solution, thereby reducing energy consumption, maintenance costs, and operating expenses compared to existing technologies. The solution concentration process mainly occurs within the plate air heat exchanger 9. The driving force for the evaporation of water in the droplets comes from the sensible heat on the hot air side and the latent heat released by the condensation of water vapor on the hot air side. The heat exchanger acts as a heat exchange medium in this process and recovers the sensible heat of the heated air and the latent heat released by the condensation of water vapor in the hot air through a common loop.

[0032] The air inlet of the third air duct 7 is connected to the heating unit 11 pipe, and the air outlet of the third air duct 7 is connected to the heat release side air inlet pipe of the plate air heat exchanger 9.

[0033] Optionally, a second temperature and humidity sensor 17 is installed inside the third air duct 7 to monitor the temperature inside the third air duct 7.

[0034] Furthermore, the second duct 6 and the third duct 7 form a ring-shaped return pipeline structure.

[0035] The air inlet of the fourth air duct 8 is connected to the heat dissipation side air outlet of the plate air heat exchanger 9. The air outlet of the fourth air duct 8 is connected to the outside air. The condensate outlet of the fourth air duct 8 is connected to the water inlet of the condensate tank 12. The first air duct 5, the second air duct 6 and the fourth air duct 8 are all provided with return grooves on their pipe walls.

[0036] Furthermore, the heat source tower solution concentration system based on the plate air heat exchanger common loop also includes: a first valve 13 and a second valve 14; the first valve 13 is installed on the pipeline between the solution return port of the first air duct 5 and the liquid inlet of the solution tank 1; the second valve 14 is installed on the pipeline between the condensate outlet of the fourth air duct 8 and the water inlet of the condensate tank 12.

[0037] Optionally, the first valve 13 is a butterfly valve.

[0038] Optionally, the second valve 13 is a butterfly valve.

[0039] Optionally, the heat source tower solution concentration system based on the plate air heat exchanger common loop further includes: a control module 15, which is electrically connected to the fan 4, solution pump 2, heating unit 11, concentration monitoring device 18, first temperature and humidity sensor 16, and second temperature and humidity sensor 17 respectively; the control module 15 is used to increase the frequency of the fan 4 when the air humidity corresponding to the second temperature and humidity sensor is greater than the air humidity corresponding to the first temperature and humidity sensor; if the frequency of the fan 4 is adjusted to the highest, and the air humidity detected by the second temperature and humidity sensor is still greater than the air humidity detected by the first temperature and humidity sensor, then the frequency of the solution pump 2 is reduced to adjust the matching relationship between the spray volume and the air flow rate, and reduce the situation where unevaporated droplets enter the heating device.

[0040] Optionally, the air temperature and moisture content decrease after heat exchange, and it is eventually discharged to the outside air through the fourth duct 8.

[0041] Optionally, the inlet of the condensate tank 12 is located at the top of the condensate tank 12.

[0042] Example 2, as Figure 2 As shown, this embodiment provides a method for concentrating a heat source tower solution based on a common loop of a plate air heat exchanger. This method is applied to the aforementioned heat source tower solution concentration system based on a common loop of a plate air heat exchanger. The method includes: S1. When the concentration process begins, the solution pump 2 sends the solution to be concentrated in the solution tank 1 to the multi-nozzle atomizing unit 3 for atomization to produce atomized solution.

[0043] S2. The fan 4 delivers air into the first air duct 5, mixes the atomized solution with the air to form a gas-liquid mixture, and then delivers it to the plate air heat exchanger 9.

[0044] S3. The plate air heat exchanger 9 performs heat exchange on the gas-liquid mixture, evaporating some of the water in the atomized solution into water vapor. The concentrated solution obtained by water evaporation flows back to the solution tank 1 through the return groove of the first air duct 5, completing the first concentration.

[0045] S4. The filter unit 10 in the second air duct 6 filters the residual solution to prevent the solution from flowing into the heating unit 11, resulting in a residual concentrated solution. Under the air supply environment of the fan 4, the residual concentrated solution is attached to the wall of the second air duct 6. The water in the residual solution in the second air duct 6 is further evaporated into unsaturated air, completing the secondary concentration.

[0046] S5. The heating unit 11 raises the air temperature in the third air duct 7 by heating, thereby obtaining high temperature and high humidity air.

[0047] S6. The plate air heat exchanger 9 performs heat exchange on high-temperature and high-humidity air, releasing the sensible and latent heat of the high-temperature and high-humidity air, and returning the condensate obtained after condensation to the condensate tank 12 through the return groove of the fourth air duct 8; wherein, the heat exchange process of the plate air heat exchanger 9 uses the gas-liquid mixture as the heat absorption side and the high-temperature and high-humidity air as the heat release side, and the gas-liquid mixture absorbs heat and the high-temperature and high-humidity air releases heat simultaneously through a complete heat exchange circuit.

[0048] S7. When the concentration process ends, the blower 4 is turned off. The return groove of the second air duct 6 will guide the residual concentrated solution suspended in the second air duct 6 to the first air duct 5. The return groove of the first air duct 5 will guide the residual concentrated solution to the solution tank 1. After the concentrated solution is collected, the secondary concentration is completed.

[0049] The technical effects of this application are as follows: 1) Based on the common loop connection method of the plate air heat exchanger, the sensible heat of hot air and the latent heat of water vapor condensation are recovered and the recovered heat is directly used to drive the evaporation of water in the atomized solution. The common loop method realizes the efficient recovery and utilization of heat and reduces the consumption of high-grade energy.

[0050] 2) High-pressure atomization enhances gas-liquid contact, allowing the solution to fully contact the air in the form of fine droplets, thus improving heat and mass transfer efficiency. Compared with traditional spray or packed tower gas-liquid contact structures, this increases the evaporation driving force and evaporation intensity per unit volume, enabling the solution to be concentrated to the target concentration in a shorter time, meeting the need for rapid solution concentration recovery during continuous operation of the heat source tower heat pump.

[0051] In summary, this application enables thorough gas-liquid mixing, improves solution concentration efficiency through two concentration cycles, and reduces concentration energy consumption and costs through a common loop plate air heat exchanger.

[0052] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0053] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A heat source tower solution concentration system based on a plate air heat exchanger common loop, characterized in that, The system includes: a solution tank, a solution pump, a multi-nozzle atomizing unit, a fan, a first air duct, a second air duct, a third air duct, a fourth air duct, a plate air heat exchanger, a filter unit, a heating unit, and a condensate tank; The outlet of the solution tank is connected to the solution pump pipeline; The solution pump passes through the pipe wall on the air outlet side of the first air duct and is connected to the multi-nozzle atomizing unit pipeline; the multi-nozzle atomizing unit is used to atomize the initial solution in the solution tank to generate an atomized solution; The fan is installed at the air inlet side of the first air duct, the air outlet of the first air duct is connected to the heat absorption side air inlet of the plate air heat exchanger, and the solution return port of the first air duct is connected to the liquid inlet pipe of the solution tank; the plate air heat exchanger is used to complete the first concentration by heating and evaporating the water in the gas-liquid mixture formed by the atomized solution and air. The air inlet of the second air duct is connected to the heat absorption side air outlet of the plate air heat exchanger, and the air outlet of the second air duct is connected to the heating unit pipeline; the filter unit is installed inside the second air duct; the filter unit is used to filter the residual solution in the air, and after the water in the residual solution in the second air duct is further evaporated to unsaturated air, the secondary concentration is completed; The air inlet of the third air duct is connected to the heating unit pipeline, and the air outlet of the third air duct is connected to the heat release side air inlet pipeline of the plate air heat exchanger. The air inlet of the fourth air duct is connected to the heat dissipation side air outlet of the plate air heat exchanger, the air outlet of the fourth air duct is connected to external air, and the condensate outlet of the fourth air duct is connected to the water inlet of the condensate tank; the first air duct, the second air duct and the fourth air duct are all provided with return grooves on their pipe walls.

2. The heat source tower solution concentration system based on a plate air heat exchanger common loop according to claim 1, characterized in that, The multi-nozzle atomizing unit includes: multiple high-pressure atomizing nozzles.

3. The heat source tower solution concentration system based on a plate air heat exchanger common loop according to claim 2, characterized in that, Each of the high-pressure atomizing nozzles is equipped with an independent on / off valve.

4. The heat source tower solution concentration system based on a plate air heat exchanger common loop according to claim 2, characterized in that, Multiple high-pressure atomizing nozzles are arranged at equal intervals along the first air duct.

5. The heat source tower solution concentration system based on a plate air heat exchanger common loop according to claim 1, characterized in that, The heat source tower solution concentration system based on a plate air heat exchanger common loop also includes: a first valve and a second valve; The first valve is installed on the pipeline between the solution return port of the first air duct and the liquid inlet of the solution tank; The second valve is installed on the pipeline between the condensate outlet of the fourth air duct and the inlet of the condensate tank.

6. The heat source tower solution concentration system based on a plate air heat exchanger common loop according to claim 5, characterized in that, The first valve is a butterfly valve.

7. The heat source tower solution concentration system based on a plate air heat exchanger common loop according to claim 5, characterized in that, The second valve is a butterfly valve.

8. The heat source tower solution concentration system based on a plate air heat exchanger common loop according to claim 1, characterized in that, The second duct and the third duct form a ring-shaped return pipeline structure.

9. The heat source tower solution concentration system based on a plate air heat exchanger common loop according to claim 1, characterized in that, The filtration device is a baffle plate.

10. A method for concentrating a heat source tower solution based on a common loop plate air heat exchanger, characterized in that, The heat source tower solution concentration method based on a plate air heat exchanger common loop is applied to the heat source tower solution concentration system based on a plate air heat exchanger common loop as described in any one of claims 1-9, and the method includes: When the concentration process begins, the solution pump pumps the solution to be concentrated in the solution tank to the multi-nozzle atomization unit for atomization, producing an atomized solution; The fan delivers air into the first air duct, mixing the atomized solution with the air to form a gas-liquid mixture before conveying it to the plate air heat exchanger. The plate-type air heat exchanger performs heat exchange on the gas-liquid mixture, evaporating some of the water in the atomized solution into water vapor. The concentrated solution obtained by water evaporation flows back to the solution tank through the return groove of the first air duct, completing the first concentration. The filter unit in the second duct filters the residual solution, preventing it from flowing into the heating unit, resulting in a residual concentrated solution. Under the air supply environment of the fan, the residual concentrated solution adheres to the wall of the second duct. The water in the residual solution in the second duct further evaporates into unsaturated air, completing the secondary concentration. The heating unit raises the air temperature inside the third air duct by heating, resulting in high-temperature and high-humidity air; The plate air heat exchanger exchanges heat with high-temperature and high-humidity air, releasing the sensible and latent heat of the high-temperature and high-humidity air, and returning the condensate obtained after condensation to the condensate tank through the return groove of the fourth air duct; wherein, the heat exchange process of the plate air heat exchanger uses the gas-liquid mixture as the heat absorption side and the high-temperature and high-humidity air as the heat release side, and the gas-liquid mixture absorbs heat and the high-temperature and high-humidity air releases heat simultaneously through a complete heat exchange circuit; When the concentration process is finished, the fan is turned off. The return groove of the second air duct will guide the residual concentrated solution suspended in the second air duct to the first air duct. The return groove of the first air duct will guide the residual concentrated solution to the solution tank. After the concentrated solution is collected, the secondary concentration is completed.

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