Surface water waste heat utilization device

Abstract

This invention relates to the field of heat and mass transfer technology and discloses a surface water waste heat utilization device, comprising: an airflow driving component, a waste heat extraction unit, a waste heat conversion unit, and a heat pump unit. The airflow driving component drives airflow to form an airflow that sequentially flows through the waste heat extraction unit and the waste heat conversion unit. The waste heat extraction unit disperses surface water into the airflow, enabling heat and moisture exchange between the surface water and the airflow to transfer heat from the surface water to the airflow. The waste heat conversion unit includes a hygroscopic heat exchange medium capable of heat and moisture exchange with the airflow to absorb heat and water vapor from the airflow. The heat pump unit includes an evaporator, and a first circulation loop of the hygroscopic heat exchange medium is formed between the heat pump unit and the waste heat conversion unit. The evaporator is connected in series in the first circulation loop to receive the heat energy released by the hygroscopic heat exchange medium, thereby extracting and converting surface water waste heat into a usable heat source for the water source heat pump in a low-temperature environment.

Description

Technical Field

[0001] This invention relates to the field of heat and mass exchange technology, and more specifically to a device for utilizing waste heat from surface water. Background Technology

[0002] In the cold regions of northern China, winter temperatures are generally low (for example, the lowest temperature in Beijing can reach around -16℃). If an air source heat pump is used for heating at this time, the low outdoor air temperature will cause the evaporation temperature of the air source heat pump unit to drop, the compression ratio to increase, the heating efficiency to decrease significantly, and it may even be difficult to operate stably.

[0003] Meanwhile, the deep water temperature of surface water bodies (such as lakes, rivers, and reservoirs) is usually stable between 1°C and 4°C. Compared to ambient air, this water contains a considerable amount of low-grade heat energy. If it can be used as a low-grade heat source for a water source heat pump, the heating efficiency of the water source heat pump unit will be greatly improved.

[0004] However, the inlet water temperature on the evaporator side of a water source heat pump unit typically needs to be above freezing point by a certain margin to prevent freezing blockage or cracking. In winter, surface water is prone to freezing, and even deep water temperatures are only in the low-temperature range of 1-4°C, close to freezing point. If directly introduced into a water source heat pump unit, freezing can easily occur within the evaporator, causing equipment damage or system shutdown. Therefore, there is an urgent need for a device that can stably extract low-grade heat from this near-freezing surface water and convert it into a reliable heat source for water source heat pump units. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that existing technologies cannot extract waste heat from surface water and convert it into a heat source suitable for use in water source heat pump units in low-temperature winter environments.

[0006] To achieve the above objectives, the present invention provides a surface water waste heat utilization device, comprising: an airflow driving component, a waste heat extraction unit, a waste heat conversion unit, and a heat pump unit, wherein... The airflow driving component is used to drive airflow to form an airflow that flows sequentially through the waste heat extraction unit and the waste heat conversion unit; The waste heat extraction unit can disperse surface water into the airflow, allowing the surface water to exchange heat and moisture with the airflow, thereby transferring the heat of the surface water to the airflow. The waste heat conversion unit includes a hygroscopic heat exchange medium, which can exchange heat and moisture with the airflow to absorb heat and water vapor in the airflow. The heat pump unit includes an evaporator, and a first circulation loop of the hygroscopic heat exchange medium is formed between the heat pump unit and the waste heat conversion unit. The evaporator is connected in series in the first circulation loop to receive the heat energy released by the hygroscopic heat exchange medium.

[0007] Preferably, the waste heat extraction unit further includes a first pumping component with the water intake located in the surface water and a first liquid distribution component located above the surface water. The first pumping component can transport the surface water to the first liquid distribution component, and the first liquid distribution component is configured to disperse the surface water into the airflow for heat and moisture exchange.

[0008] More preferably, the waste heat extraction unit further includes a first guide duct disposed above the surface water and sleeved on the first liquid distribution component, and the waste heat conversion unit includes a second guide duct connected to the first guide duct. The first guide duct and the second guide duct have an air inlet and an air outlet respectively connected to the air. The airflow driving component is disposed inside the first guide duct and / or the second guide duct, so that the airflow flows sequentially through the waste heat extraction unit and the waste heat conversion unit.

[0009] More preferably, the first air duct is provided with a gas-liquid separation component, which is used to block at least part of the liquid water and allow the airflow to enter the waste heat conversion unit.

[0010] More preferably, the bottom of the inlet of the first guide duct is configured as a slope with an angle relative to the horizontal plane, and the first guide duct is provided with a flushing component, which is configured to receive the surface water from the first pumping component to flush the slope to remove ice slag.

[0011] Preferably, the waste heat extraction unit further includes a flow disturbance component, which is disposed at and / or below the surface water surface. The flow disturbance component is configured to receive the surface water from the first pumping component and to spray water onto the water surface to agitate the water surface and prevent the water surface from freezing.

[0012] Preferably, the waste heat conversion unit further includes a solution pool for containing the hygroscopic heat exchange medium, a second pumping component for driving the hygroscopic heat exchange medium to flow along the first circulation loop, and a second liquid distribution component disposed in the second guide duct. The solution pool, the second pumping component, the evaporator, and the second liquid distribution component are connected in series in the first circulation loop. The solution pool is connected to the lower end of the second guide duct. The second liquid distribution component is configured to disperse the hygroscopic heat exchange medium into the airflow for heat and moisture exchange, and the hygroscopic heat exchange medium can fall back into the solution pool under gravity to form the first circulation loop.

[0013] More preferably, a gas-liquid contact element is provided between the second liquid distribution component and the solution pool. The gas-liquid contact element has a surface and a channel through which the hygroscopic heat exchange medium flows. After flowing out of the second liquid distribution component, the hygroscopic heat exchange medium can first flow through the gas-liquid contact element and then fall back into the solution pool.

[0014] Preferably, it further includes a solution concentration unit, which forms a second circulation loop for the hygroscopic heat exchange medium with the waste heat conversion unit. The solution concentration unit is used to concentrate the diluted hygroscopic heat exchange medium in the waste heat conversion unit and send it back to the waste heat conversion unit to maintain the concentration of the hygroscopic heat exchange medium.

[0015] More preferably, the solution concentration unit includes an evaporation vessel for evaporating moisture in the hygroscopic heat exchange medium into low-temperature water vapor, a third pumping component for conveying the hygroscopic heat exchange medium from the waste heat conversion unit to the evaporation vessel, and a fourth pumping component for conveying the hygroscopic heat exchange medium from the evaporation vessel to the waste heat conversion unit. The waste heat conversion unit, the third pumping component, the evaporation vessel, and the fourth pumping component are connected in series to form the second circulation loop.

[0016] More preferably, the solution concentration unit further includes a second compressor for receiving and compressing the low-temperature water vapor into high-temperature water vapor, and the evaporation vessel is provided with a heat exchange component for receiving the high-temperature water vapor to heat the hygroscopic heat exchange medium, wherein the high-temperature water vapor can indirectly exchange heat with the hygroscopic heat exchange medium and condense into high-temperature water.

[0017] More preferably, the solution concentration unit further includes a preheating component for receiving the high-temperature water to heat the hygroscopic heat exchange medium. The preheating component has a heat medium inlet, a heat medium outlet, a cold medium inlet, and a cold medium outlet. The cold medium inlet and the cold medium outlet of the preheating component are respectively connected to the third pumping component and the evaporation kettle. The heat medium inlet of the preheating component is connected to the heat exchange component. The heat medium outlet of the preheating component is connected to a drain pipe so that the high-temperature water can indirectly exchange heat with the hygroscopic heat exchange medium and be cooled to low-temperature water before being discharged through the drain pipe.

[0018] More preferably, the evaporator is further provided with an auxiliary heating component for heating the hygroscopic heat exchange medium.

[0019] Through the above technical solution, the present invention utilizes airflow as a heat carrier. The heat of the surface water is transferred to the airflow through the first heat and moisture exchange, and then the heat and water vapor in the airflow are absorbed by the hygroscopic heat exchange medium through the second heat and moisture exchange. Subsequently, the heated hygroscopic heat exchange medium is transported to the heat pump unit to release heat, thereby transferring the low-grade heat in the surface water step by step and converting it into a heat source that can be used by the water source heat pump unit. Attached Figure Description

[0020] Figure 1 This is a surface water waste heat utilization device according to a preferred embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures 1-Airflow drive component; 10- Waste heat extraction unit; 11- First pumping component; 12- Turbulence component; 13- First liquid distribution component; 14- Flushing component; 15- First guide duct; 151- Air inlet; 152- Slope; 16- Waterproof membrane; 17- Water barrier; 20 - Waste heat conversion unit; 21 - Second guide duct; 212 - Air outlet; 22 - Second pumping component; 23 - Second liquid distribution component; 24 - Gas-liquid contact element; 25 - Solution tank; 30-Heat pump unit; 31-First compressor; 32-Condenser; 33-Throttling component; 34-Evaporator; 35-Hot water inlet; 36-Hot water outlet; 40 - Solution concentration unit; 41 - Third pumping component; 42 - Preheating component; 43 - Fourth pumping component; 44 - Evaporation kettle; 45 - Second compressor; 46 - Heat exchange component; 47 - Auxiliary heating component; 48 - Drain pipe. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] In this invention, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to the up, down, left, and right positions shown with reference to the accompanying drawings. "Inner" and "outer" refer to the inner and outer contours relative to the individual components themselves.

[0024] Reference Figure 1 As shown, this invention utilizes airflow as a heat carrier. A first heat-moisture exchange transfers heat from the surface water to the airflow. A second heat-moisture exchange occurs, where a hygroscopic heat exchange medium absorbs heat and water vapor from the airflow. The heated hygroscopic heat exchange medium is then transported to a heat pump unit to release heat. This process progressively transfers and converts the low-grade heat in the surface water into a heat source usable by a water source heat pump unit. The surface water waste heat utilization device includes an airflow drive component 1, a waste heat extraction unit 10, a waste heat conversion unit 20, and a heat pump unit 30.

[0025] Specifically, such as Figure 1 As shown, the airflow driving component 1 is used to drive airflow to form an airflow that flows sequentially through the waste heat extraction unit 10 and the waste heat conversion unit 20. This airflow serves as the aforementioned heat carrier. The airflow driving component 1 can be installed in either the waste heat extraction unit 10 or the waste heat conversion unit 20, as long as it can drive air to flow sequentially through the waste heat extraction unit 10 and the waste heat conversion unit 20. Preferably, the airflow driving component 1 can be a fan, such as an axial flow fan or a centrifugal fan.

[0026] The waste heat extraction unit 10 disperses surface water into the airflow, enabling heat and moisture exchange between the surface water and the airflow to transfer heat from the surface water to the airflow. Specifically, after being dispersed into the airflow by the waste heat extraction unit 10, the surface water comes into direct contact with the flowing airflow. Since the surface water temperature is higher than the ambient air temperature, heat is transferred from the surface water to the airflow through sensible heat exchange, raising the airflow temperature. Simultaneously, some of the surface water evaporates into water vapor and enters the airflow, introducing latent heat into the airflow and increasing its humidity. After the aforementioned heat and moisture exchange, both the temperature and humidity of the airflow increase, and the low-grade heat energy in the surface water is transferred to the airflow, completing the conversion of liquid waste heat in the surface water into gaseous waste heat.

[0027] The waste heat conversion unit 20 includes a hygroscopic heat exchange medium that can exchange heat and moisture with the airflow to absorb heat and water vapor from the airflow. Specifically, the hygroscopic heat exchange medium is a solution with hygroscopic properties, capable of absorbing water vapor from the airflow and condensing it into liquid water. This condensation process releases a large amount of latent heat of condensation. Simultaneously, the hygroscopic heat exchange medium also has antifreeze properties, with a freezing point lower than that of surface water, ensuring it remains liquid and does not freeze under low-temperature conditions in winter. After being processed by the waste heat extraction unit 10, the airflow has increased temperature and humidity. When this airflow comes into contact with the hygroscopic heat exchange medium, on the one hand, heat in the airflow is transferred to the hygroscopic heat exchange medium through sensible heat exchange; on the other hand, the hygroscopic heat exchange medium absorbs water vapor from the airflow, utilizing the large amount of latent heat of condensation released by the water vapor condensation to obtain heat. After the aforementioned heat and moisture exchange, the hygroscopic heat exchange medium absorbs heat and water vapor from the airflow, causing its temperature to rise and completing the transfer of heat from the airflow to the hygroscopic heat exchange medium. Preferably, the hygroscopic heat exchange medium can be a lithium bromide solution.

[0028] The heat pump unit 30 includes an evaporator 34. A first circulation loop for the hygroscopic heat exchange medium is formed between the heat pump unit 30 and the waste heat conversion unit 20. The evaporator 34 is connected in series in the first circulation loop to receive the heat energy released by the hygroscopic heat exchange medium. The heat pump unit 30 is the aforementioned water source heat pump unit, and its principle is based on the reverse Carnot cycle. Specifically, the heat pump unit 30 may also include a first compressor 31, a condenser 32, a throttling device 33, a hot water inlet 35, and a hot water outlet 36. The working fluid of the heat pump unit 30 is a refrigerant. The refrigerant absorbs heat released from the hygroscopic heat exchange medium in the waste heat conversion unit 20 within the evaporator 34, vaporizing into a low-temperature, low-pressure gaseous refrigerant. This low-temperature, low-pressure gaseous refrigerant is then compressed by the first compressor 31 into a high-temperature, high-pressure gaseous refrigerant, which subsequently enters the condenser 32. In the condenser 32, the high-temperature, high-pressure gaseous refrigerant indirectly exchanges heat with circulating water entering the condenser 32 from the hot water inlet 35. After releasing heat, the high-temperature, high-pressure gaseous refrigerant liquefies into a high-pressure liquid refrigerant. The circulating water absorbs heat, its temperature rises, and it flows out from the hot water outlet 36, completing the hot water preparation. The high-pressure liquid refrigerant is then throttled and depressurized by the throttling component 33, becoming a low-temperature, low-pressure liquid refrigerant, which re-enters the evaporator 34 to continue exchanging heat with the hygroscopic heat exchange medium from the waste heat conversion unit 20. After releasing heat and cooling in the evaporator 34, the hygroscopic heat exchange medium returns to the waste heat conversion unit 20 for further heat absorption, forming the first circulation loop of the hygroscopic heat exchange medium.

[0029] It is understood that the core objective of this invention is achieved by receiving the heat released by the hygroscopic heat exchange medium via the evaporator 34. Other components in the heat pump unit 30, such as the first compressor 31, condenser 32, and throttling device 33, are used to further enhance the quality of the heat before supplying it to the user side, and their specific forms do not constitute a limitation on this invention.

[0030] Thus, the present invention drives the airflow through the airflow drive component 1 to flow through the waste heat extraction unit 10 and the waste heat conversion unit 20 in sequence. The airflow is used as a heat carrier. The low-grade heat in the surface water is transferred to the airflow through the first heat and moisture exchange. Then, the heat and water vapor in the airflow are absorbed by the hygroscopic heat exchange medium through the second heat and moisture exchange. The heated hygroscopic heat exchange medium is then transported to the evaporator 34 of the heat pump unit 30 to release heat, thus completing the continuous supply of waste heat from the surface water to the heat pump unit 30.

[0031] like Figure 1 As shown, the waste heat extraction unit 10 also includes a first pumping component 11 with its intake in the surface water and a first liquid distribution component 13 positioned above the surface water. The first pumping component 11 transports the surface water to the first liquid distribution component 13, which disperses the surface water into an airflow for heat and moisture exchange. The first pumping component 11 provides the power for transporting the surface water, and its intake is submerged in a deeper layer below the surface water surface. The water temperature at this location is higher than the surface water temperature, allowing for the acquisition of relatively warm surface water to facilitate heat and moisture exchange. Simultaneously, the submersion of the intake ensures continuous water intake. The first pumping component 11 can be a submersible pump, centrifugal pump, or self-priming pump, etc. The specific type and specifications can be determined by those skilled in the art based on actual operating conditions. Preferably, a filter component (such as a filter screen or filter cover) can also be installed at the intake to prevent debris such as silt and aquatic plants from entering the first pumping component 11.

[0032] The first liquid distribution component 13 is used to uniformly disperse surface water into the airflow, thereby increasing the contact area between the surface water and the airflow and improving the heat and moisture exchange efficiency. The first liquid distribution component 13 can take the form of a spray device, a distribution pipe, an overflow trough, or an atomizing nozzle. Preferably, the first liquid distribution component 13 can be a spray device, which sprays surface water into fine droplets through a spray head, distributing it evenly in the airflow. Alternatively, the first liquid distribution component 13 can also be a distribution pipe, where distribution holes in the pipe wall allow surface water to flow down in a linear or curtain-like pattern; or it can be an overflow trough, where the overflow edge forms a liquid film or liquid curtain; or it can be a spray nozzle, atomizing the surface water into even finer droplets. All of the above structures can achieve the purpose of dispersing surface water into the airflow, and those skilled in the art can choose the appropriate form according to the actual working conditions.

[0033] To constrain the airflow path, the waste heat extraction unit 10 further includes a first guide duct 15, and the waste heat conversion unit 20 further includes a second guide duct 21. The first guide duct 15 is positioned above the surface water and fitted onto the first liquid distribution component 13. The second guide duct 21 is connected to the first guide duct 15. The first guide duct 15 and the second guide duct 21 each have an air inlet 151 and an air outlet 212 communicating with the air. An airflow driving component 1 is disposed within the first guide duct 15 and / or the second guide duct 21, so that the airflow sequentially passes through the waste heat extraction unit 10 and the waste heat conversion unit 20. Specifically, under the drive of the airflow driving component 1, the airflow enters the first guide duct 15 from the air inlet 151; inside the first guide duct 15, the airflow exchanges heat and moisture with the surface water, and then enters the second guide duct 21 under the drive of the airflow driving component 1; inside the second guide duct 21, the airflow exchanges heat and moisture with the hygroscopic heat exchange medium, and then is discharged from the air outlet 212 under the drive of the airflow driving component 1.

[0034] During the heat and moisture exchange process, some of the unevaporated surface water, after being dispersed by the first liquid distribution component 13, may be carried by the airflow in the form of liquid water droplets towards the waste heat conversion unit 20. If not intercepted, these liquid water droplets will enter the waste heat conversion unit 20 with the airflow, causing the hygroscopic heat exchange medium to be further diluted and its concentration to decrease rapidly, thereby shortening its effective working cycle and increasing the operating load of the solution concentration unit (which will be detailed later). Therefore, a gas-liquid separation component can be installed inside the first guide duct 15. This component is used to block at least a portion of the liquid water while allowing the airflow to enter the waste heat conversion unit 20. It should be noted that the gas-liquid separation component intercepts liquid water, not gaseous water vapor. Specifically, the gas-liquid separation component can be located near the connection between the first guide duct 15 and the second guide duct 21, and is used to intercept at least a portion of the liquid water droplets carried by the airflow as it is about to leave the first guide duct 15. The gas-liquid separation component can be a waterproof plate 16. The waterproof plate 16 can take the form of a rainproof louvered air vent, a wire mesh demister, or a baffle plate, as long as it can achieve gas-liquid separation. Those skilled in the art can choose a suitable form according to the actual working conditions. Furthermore, a water-blocking sill 17 can be provided at the lower end of the waterproof plate 16. The water-blocking sill 17 is used to prevent water from accumulating at the bottom of the first guide duct 15 and overflowing into the waste heat conversion unit 20.

[0035] When surface water exchanges heat and moisture with airflow in the low-temperature environment of winter, some of the unevaporated surface water falls to the bottom of the first guide duct 15, where it accumulates and freezes to form ice slag. If not removed in time, the ice slag will gradually accumulate, affecting the airflow and heat and moisture exchange efficiency within the first guide duct 15, and may even block the airflow channel. Therefore, the bottom of the inlet of the first guide duct 15 can be set as a slope 152 with an angle relative to the horizontal plane. The first guide duct 15 is equipped with a flushing component 14, which is configured to receive surface water from the first pumping component 11 to flush the slope 152 and remove the ice slag. Specifically, the flushing component 14 may include a nozzle, which is located above the slope 152 or at a high point on the slope 152 and close to the gas-liquid separation component. The nozzle sprays water towards the lower part of the slope 152 to spray surface water onto the slope 152. The impact force of the water flow disperses the ice slag accumulated on the slope 152 and discharges the ice slag along the slope 152 under the carrying force of the water flow.

[0036] To prevent water surface freezing, the waste heat extraction unit 10 also includes a flow-dispersing component 12. The flow-dispersing component 12 is positioned at and / or below the surface water level. It is configured to receive surface water from the first pumping component 11 and spray water onto the surface to agitate it. Since the intake of the first pumping component 11 is submerged in a deep layer below the surface water, relatively warm deep water (i.e., surface water at a deep layer) can be transported to the flow-dispersing component 12 and sprayed onto the surface. This replenishes heat to the surface water (i.e., the surface water at the surface), raising its temperature. Simultaneously, the jetting motion of the water disrupts the thermal conditions for ice crystal formation. These two actions work together to delay water surface freezing. Preferably, the flow-dispersing component 12 may include a nozzle, through which water is sprayed onto the surface, creating a fountain-like disturbance to enhance the mixing effect between deep and surface water and improve the anti-freezing effect.

[0037] With the above arrangement, the first pumping component 11 can deliver surface water to the first liquid distribution component 13, the flushing component 14 and the turbulence component 12 respectively, thereby realizing one pump for multiple supplies. There is no need to set up separate pumping components for the flushing component 14 and the turbulence component 12, which helps to simplify the device structure, reduce equipment costs and operating energy consumption.

[0038] like Figure 1As shown, the waste heat conversion unit 20 also includes a solution tank 25, a second pumping component 22, and a second liquid distribution component 23. The solution tank 25 is connected to the lower end of the second guide duct 21 and is used to contain the hygroscopic heat exchange medium. The second pumping component 22 drives the hygroscopic heat exchange medium to flow along the first circulation loop. In application, a suitable pump type can be selected according to the properties of the hygroscopic heat exchange medium. For example, when the hygroscopic heat exchange medium is a lithium bromide solution, the second pumping component 22 can be a shielded pump or a magnetic pump, which have good sealing and corrosion resistance. The second liquid distribution component 23 is disposed within the second guide duct 21. The solution pool 25, the second pumping component 22, the evaporator 34, and the second liquid distribution component 23 are sequentially connected in series in the first circulation loop. Thus, the second pumping component 22 can sequentially transport the hygroscopic heat exchange medium in the solution pool 25 to the evaporator 34 and the second liquid distribution component 23. The second liquid distribution component 23 is configured to disperse the hygroscopic heat exchange medium into the airflow for heat and moisture exchange, and the hygroscopic heat exchange medium can fall back into the solution pool 25 under gravity to form the first circulation loop. The second liquid distribution component 23 can be a spray device, which sprays the hygroscopic heat exchange medium into fine droplets through spray nozzles, distributing them evenly in the airflow to increase the contact area between the hygroscopic heat exchange medium and the airflow, thereby improving the heat and moisture exchange efficiency.

[0039] To further increase the contact area and extend the contact time between the hygroscopic heat exchange medium and the airflow, a gas-liquid contact element 24 is provided between the second liquid distribution component 23 and the solution pool 25. The gas-liquid contact element 24 has a surface and a channel through which the hygroscopic heat exchange medium flows. The surface allows the hygroscopic heat exchange medium to adhere and form a liquid film, while the channel allows the airflow to pass through and contact the liquid film for heat and moisture exchange. Simultaneously, the channel also serves as a flow path for the hygroscopic heat exchange medium, allowing it to flow through the gas-liquid contact element 24 before returning to the solution pool 25 after exiting the second liquid distribution component 23. The gas-liquid contact element 24 can be made of packing material, which has advantages such as a large specific surface area and good wettability, effectively increasing the contact area and extending the contact time between the hygroscopic heat exchange medium and the airflow, thereby improving the heat and moisture exchange efficiency.

[0040] In a preferred embodiment, the outlet 212 of the second guide duct 21 is positioned above the second liquid distribution component 23, and the airflow is configured to flow upward through the gas-liquid contact element 24 (i.e., the airflow within the gas-liquid contact element 24 flows upward). The second liquid distribution component 23, located above the gas-liquid contact element 24, disperses the hygroscopic heat transfer medium downwards onto the gas-liquid contact element 24. Under gravity, the hygroscopic heat transfer medium flows downwards along the surface and channels of the gas-liquid contact element 24, forming a counter-current contact with the upward-flowing airflow, thereby facilitating sufficient heat and moisture exchange. This counter-current arrangement is beneficial for increasing the driving force for heat and mass transfer between the gas and liquid phases, further improving the heat and moisture exchange efficiency.

[0041] like Figure 1 As shown, the surface water waste heat utilization device of the present invention also includes a solution concentration unit 40. Since the hygroscopic heat exchange medium is gradually diluted after continuously absorbing water vapor from the airflow in the waste heat conversion unit 20, resulting in a decrease in its concentration and a weakening of its hygroscopic and antifreeze properties, a solution concentration unit 40 is provided to restore its concentration. A second circulation loop for the hygroscopic heat exchange medium is formed between the solution concentration unit 40 and the waste heat conversion unit 20. The solution concentration unit 40 is used to concentrate the diluted hygroscopic heat exchange medium in the waste heat conversion unit 20 and return it to the waste heat conversion unit 20 to maintain the concentration of the hygroscopic heat exchange medium.

[0042] Specifically, the solution concentration unit 40 includes an evaporation kettle 44, a third pumping component 41, and a fourth pumping component 43. The evaporation kettle 44 evaporates moisture in the hygroscopic heat exchange medium into low-temperature water vapor, thereby increasing the concentration of the hygroscopic heat exchange medium. The third pumping component 41 transports the hygroscopic heat exchange medium from the waste heat conversion unit 20 to the evaporation kettle 44, and the fourth pumping component 43 transports the hygroscopic heat exchange medium from the evaporation kettle 44 to the waste heat conversion unit 20. The waste heat conversion unit 20, the third pumping component 41, the evaporation kettle 44, and the fourth pumping component 43 are connected in series to form a second circulation loop. Thus, the diluted hygroscopic heat exchange medium in the waste heat conversion unit 20 is transported to the evaporation kettle 44 for concentration through the second circulation loop, and then returned to the waste heat conversion unit 20 to maintain the concentration of the hygroscopic heat exchange medium in the waste heat conversion unit 20 within a set range. It is worth noting that the degree of evaporation can be adjusted by those skilled in the art using conventional control methods based on solution concentration monitoring results. The third pumping component 41 and the fourth pumping component 43 can adopt the same pump type as the second pumping component 22 (such as a canned pump or a magnetic pump), and their specific type and specifications can be determined by those skilled in the art according to actual needs.

[0043] Furthermore, the solution concentration unit 40 also includes a second compressor 45 and a heat exchange component 46. The second compressor 45 receives and compresses low-temperature water vapor into high-temperature water vapor. The heat exchange component 46, located within the evaporation vessel 44, receives the high-temperature water vapor to heat the hygroscopic heat exchange medium. The high-temperature water vapor can indirectly exchange heat with the hygroscopic heat exchange medium and condense into high-temperature water. The heat exchange component 46 can be a coil heat exchanger, a shell-and-tube heat exchanger, or a plate heat exchanger, etc., and those skilled in the art can select a suitable form based on the structure and space conditions of the evaporation vessel 44. Thus, the low-temperature water vapor generated in the evaporation vessel 44 is compressed into high-temperature water vapor by the second compressor 45, and then the heat is recycled back to heat the hygroscopic heat exchange medium within the evaporation vessel 44 via the heat exchange component 46, achieving the recycling of heat within the solution concentration unit 40 and reducing external energy consumption.

[0044] Furthermore, the solution concentration unit 40 also includes a preheating component 42. The preheating component 42 receives high-temperature water to heat the hygroscopic heat exchange medium about to enter the evaporation vessel 44, and has a heat medium inlet, a heat medium outlet, a cold medium inlet, and a cold medium outlet. The cold medium inlet and outlet of the preheating component 42 are respectively connected to the third pumping component 41 and the evaporation vessel 44. The heat medium inlet of the preheating component 42 is connected to the heat exchange component 46, and the heat medium outlet of the preheating component 42 is connected to a drain pipe 48, so that the high-temperature water can indirectly exchange heat with the hygroscopic heat exchange medium and cool down to low-temperature water before being discharged through the drain pipe 48. The hygroscopic heat exchange medium from the third pumping component 41 enters the preheating component 42 through the cold medium inlet, and indirectly exchanges heat with the high-temperature water from the heat exchange component 46 (i.e., high-temperature water formed by the condensation of high-temperature water vapor in the heat exchange component 46). After absorbing heat, its temperature rises, and it then enters the evaporation vessel 44 through the cold medium outlet. The high-temperature water cools down to low-temperature water after releasing heat and is discharged through the drain pipe 48. Therefore, by using the heat of high-temperature water to preheat the hygroscopic heat exchange medium that is about to enter the evaporator 44, the external heat input required in the evaporator 44 is reduced, which can further improve the thermal energy utilization efficiency in the solution concentration unit 40.

[0045] In addition, an auxiliary heating component 47 for heating the hygroscopic heat exchange medium is also provided inside the evaporator 44. Specifically, the auxiliary heating component 47 is used to provide an auxiliary heat source for the hygroscopic heat exchange medium when the evaporator 44 is started up, so as to accelerate the evaporator 44 to reach the optimal operating temperature. During the start-up stage of the evaporator 44, the temperature of the hygroscopic heat exchange medium inside the evaporator 44 is low and the evaporation rate is slow. At this time, the auxiliary heating component 47 can be turned on to preheat the hygroscopic heat exchange medium, so that the temperature inside the evaporator 44 can be quickly raised to the evaporation temperature. When the evaporator 44 enters a stable operating state, the circulating heat provided by the second compressor 45 and the heat exchange component 46 can maintain the evaporation temperature inside the evaporator 44, and the auxiliary heating component 47 stops working to reduce operating energy consumption.

[0046] It is understood that the transport of surface water and hygroscopic heat exchange medium between the components involved in this article can be achieved through conventional pipeline connection methods in the field. The specific route and connection form can be set by those skilled in the art according to actual needs, and will not be elaborated in this article.

[0047] In summary, the working process of the surface water waste heat utilization device of the present invention is as follows: Driven by the airflow drive component 1, the airflow enters the first guide duct 15 from the air inlet 151, where it undergoes a first heat and moisture exchange with the surface water dispersed by the first liquid distribution component 13. The low-grade heat in the surface water is transferred to the airflow, causing the airflow temperature and humidity to increase. Subsequently, the airflow passes through the gas-liquid separation component to separate at least a portion of the liquid water it carries, and then enters the second guide duct 21. The hygroscopic heat exchange medium is dispersed onto the gas-liquid contact element 24 by the second liquid distribution component 23. The airflow then passes upward through the gas-liquid contact element 24, where it undergoes a second heat and moisture exchange with the hygroscopic heat exchange medium. The hygroscopic heat exchange medium absorbs heat and water vapor from the airflow, causing its temperature to rise and its concentration to decrease. The airflow is then discharged from the air outlet 212. The heated hygroscopic heat exchange medium falls back into the solution pool 25 and is then transported to the evaporator 34 of the heat pump unit 30 by the second pumping component 22. After releasing heat and cooling down in the evaporator 34, it returns to the second liquid distribution component 23, forming the first circulation loop. The diluted hygroscopic heat exchange medium is transported to the solution concentration unit 40 via the third pumping component 41. After concentration, it is returned to the solution pool 25 by the fourth pumping component 43, forming a second circulation loop to maintain the concentration of the hygroscopic heat exchange medium within the set range.

[0048] The above operating process assumes that the ambient air temperature is lower than the surface water temperature at the water intake of the first pumping component 11, and the temperature difference between the two is greater than a set value. In this case, the first pumping component 11 starts, and the airflow undergoes the first heat and moisture exchange before entering the waste heat conversion unit 20. When the ambient air temperature is higher than the surface water temperature, the first pumping component 11 does not start, and the airflow can directly enter the waste heat conversion unit 20 to exchange heat and moisture with the hygroscopic heat exchange medium. The detection and judgment of the above temperatures can be achieved using conventional temperature detection elements and control logic. Those skilled in the art can set the corresponding start-up threshold according to actual needs.

[0049] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A surface water waste heat utilization device, characterized in that, include: The components include an airflow drive unit (1), a waste heat extraction unit (10), a waste heat conversion unit (20), and a heat pump unit (30), among which... The airflow driving component (1) is used to drive airflow to form an airflow that flows sequentially through the waste heat extraction unit (10) and the waste heat conversion unit (20); The waste heat extraction unit (10) can disperse surface water into the airflow, so that the surface water and the airflow can exchange heat and moisture, thereby transferring the heat of the surface water to the airflow. The waste heat conversion unit (20) includes a hygroscopic heat exchange medium, which can exchange heat and moisture with the air flow to absorb heat and water vapor in the air flow; The heat pump unit (30) includes an evaporator (34), and a first circulation loop of the hygroscopic heat exchange medium is formed between the heat pump unit (30) and the waste heat conversion unit (20). The evaporator (34) is connected in series to the first circulation loop to receive the heat energy released by the hygroscopic heat exchange medium.

2. The surface water waste heat utilization device according to claim 1, characterized in that, The waste heat extraction unit (10) further includes a first pumping component (11) with the water intake located in the surface water and a first liquid distribution component (13) located above the surface water. The first pumping component (11) can transport the surface water to the first liquid distribution component (13), and the first liquid distribution component (13) is configured to disperse the surface water into the airflow for heat and moisture exchange.

3. The surface water waste heat utilization device according to claim 2, characterized in that, The waste heat extraction unit (10) further includes a first guide duct (15) disposed above the surface water and sleeved on the first liquid distribution component (13). The waste heat conversion unit (20) includes a second guide duct (21) connected to the first guide duct (15). The first guide duct (15) and the second guide duct (21) have an air inlet (151) and an air outlet (212) respectively connected to the air. The airflow driving component (1) is disposed in the first guide duct (15) and / or the second guide duct (21) so that the airflow flows sequentially through the waste heat extraction unit (10) and the waste heat conversion unit (20).

4. The surface water waste heat utilization device according to claim 3, characterized in that, The first air duct (15) is provided with a gas-liquid separation component, which is used to block at least part of the liquid water and allow the air flow to enter the waste heat conversion unit (20).

5. The surface water waste heat utilization device according to claim 3, characterized in that, The bottom of the inlet of the first guide duct (15) is set as a slope (152) with an angle relative to the horizontal plane. The first guide duct (15) is provided with a flushing component (14), which is configured to receive the surface water from the first pumping component (11) to flush the slope (152) to remove ice slag.

6. The surface water waste heat utilization device according to claim 2, characterized in that, The waste heat extraction unit (10) further includes a turbulence-disrupting component (12), which is disposed at and / or below the surface water. The turbulence-disrupting component (12) is configured to receive the surface water from the first pumping component (11) and to spray water onto the surface to agitate the surface and prevent the surface from freezing.

7. The surface water waste heat utilization device according to claim 3, characterized in that, The waste heat conversion unit (20) further includes a solution pool (25) for containing the hygroscopic heat exchange medium, a second pumping component (22) for driving the hygroscopic heat exchange medium to flow along the first circulation loop, and a second liquid distribution component (23) disposed in the second guide duct (21). The solution pool (25), the second pumping component (22), the evaporator (34) and the second liquid distribution component (23) are connected in series in the first circulation loop. The solution pool (25) is connected to the lower end of the second guide duct (21). The second liquid distribution component (23) is configured to disperse the hygroscopic heat exchange medium into the airflow for heat and moisture exchange, and the hygroscopic heat exchange medium can fall back to the solution pool (25) under gravity to form the first circulation loop.

8. The surface water waste heat utilization device according to claim 7, characterized in that, A gas-liquid contact element (24) is provided between the second liquid distribution component (23) and the solution pool (25). The gas-liquid contact element (24) has a surface and a channel through which the hygroscopic heat exchange medium flows. After the hygroscopic heat exchange medium flows out through the second liquid distribution component (23), it can first flow through the gas-liquid contact element (24) and then fall back into the solution pool (25).

9. The surface water waste heat utilization device according to claim 1, characterized in that, It also includes a solution concentration unit (40), which forms a second circulation loop for the hygroscopic heat exchange medium between the solution concentration unit (40) and the waste heat conversion unit (20). The solution concentration unit (40) is used to concentrate the diluted hygroscopic heat exchange medium in the waste heat conversion unit (20) and send it back to the waste heat conversion unit (20) to maintain the concentration of the hygroscopic heat exchange medium.

10. The surface water waste heat utilization device according to claim 9, characterized in that, The solution concentration unit (40) includes an evaporator (44) for evaporating moisture in the hygroscopic heat exchange medium into low-temperature water vapor, a third pumping component (41) for conveying the hygroscopic heat exchange medium from the waste heat conversion unit (20) to the evaporator (44), and a fourth pumping component (43) for conveying the hygroscopic heat exchange medium from the evaporator (44) to the waste heat conversion unit (20). The waste heat conversion unit (20), the third pumping component (41), the evaporator (44), and the fourth pumping component (43) are connected in series to form the second circulation loop.

11. The surface water waste heat utilization device according to claim 10, characterized in that, The solution concentration unit (40) further includes a second compressor (45) for receiving and compressing the low-temperature water vapor into high-temperature water vapor. The evaporation vessel (44) is provided with a heat exchange component (46) for receiving the high-temperature water vapor to heat the hygroscopic heat exchange medium. The high-temperature water vapor can indirectly exchange heat with the hygroscopic heat exchange medium and condense into high-temperature water.

12. The surface water waste heat utilization device according to claim 11, characterized in that, The solution concentration unit (40) further includes a preheating component (42) for receiving the high-temperature water to heat the hygroscopic heat exchange medium. The preheating component (42) has a heat medium inlet, a heat medium outlet, a cold medium inlet, and a cold medium outlet. The cold medium inlet and the cold medium outlet of the preheating component (42) are respectively connected to the third pumping component (41) and the evaporator (44). The heat medium inlet of the preheating component (42) is connected to the heat exchange component (46). The heat medium outlet of the preheating component (42) is connected to a drain pipe (48) so that the high-temperature water can indirectly exchange heat with the hygroscopic heat exchange medium and be cooled to low-temperature water before being discharged through the drain pipe (48).

13. The surface water waste heat utilization device according to claim 10, characterized in that, An auxiliary heating component (47) for heating the hygroscopic heat exchange medium is also provided inside the evaporator (44).

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