Method and system for enhancing heat exchange in gas cooling process

Abstract

The invention relates to a method and system for strengthening heat exchange in the gas cooling process, the system comprises a heat exchanger, a cold source, a spraying system and a water tank, the heat exchanger is connected with the cold source, then water spraying is conducted on the air inlet side of the heat exchanger through the spraying system, a water film is formed on the surface of the heat exchanger through water spraying, and the water film is disturbed; water sprayed by the spraying system flows into the water tank, and the water tank conveys the water to the spraying system through a water pump. According to the novel method and system, a water film is formed on the gas side of the gas-liquid heat exchanger, disturbance of the water film is increased through spraying, meanwhile, solid particulate matter is added into spraying water, the stability of a boundary layer is broken, and the boundary layer comprises a liquid boundary layer and a gas-liquid boundary layer. According to the method, heat exchange can be efficiently enhanced, and the convective heat exchange coefficient is greatly increased.

Description

Technical Field

[0001] The present invention relates to the technical field of cooling and heat exchange, and in particular to a method and system for enhancing heat exchange in a gas cooling process. Background Art

[0002] The cooling of gases is a common process in industry and a fundamental element of air handling and air conditioning. It's well known that the convective heat transfer performance of gases is significantly inferior to that of liquids. This results in large gas-to-gas heat exchangers, requiring a large heat transfer area. The gas side of a gas-to-liquid heat exchanger often becomes the primary thermal resistance, reducing heat transfer efficiency. Summary of the Invention

[0003] The object of the present invention is to provide a method and system for enhancing heat exchange in a gas cooling process, so as to solve the problems encountered in the above-mentioned background technology.

[0004] To achieve the above object, the technical solution of the present invention is as follows:

[0005] A method for enhancing heat exchange in a gas cooling process comprises a heat exchanger, a cold source, a spray system and a water tank, wherein the heat exchanger is first connected to the cold source, and then the air inlet side of the heat exchanger is sprayed with water through the spray system, so that a water film is formed on the surface of the heat exchanger by the water spraying and the water film is disturbed; the water sprayed by the spray system flows into the water tank, and the water tank transports the water to the spray system through a water pump.

[0006] In the above solution, a solid particulate matter generator is installed on the connecting pipe of the spray system. When the solid particulate matter generator is in operation, solid particulate matter is generated. The solid particulate matter is sprayed onto the entire air inlet side of the heat exchanger by the spray system, and the particulate matter destroys the gas-liquid boundary layer.

[0007] As a preferred solution, the water spraying system uses a pulsed spraying method, with the spraying pressure and flow rate varying periodically. This can reduce pump energy consumption and enhance the disturbance of the water film. The solid particulate matter generated by the solid particulate matter generator is nano-sized particulate matter that is insoluble or slightly soluble in water.

[0008] A system for enhancing heat exchange in a gas cooling process comprises a heat exchanger, a cold source, a spray system and a water tank. The liquid supply pipe of the cold source is connected to the liquid inlet pipe in the heat exchanger, and the liquid outlet pipe in the heat exchanger is connected to the cold source via a liquid return pipe. The water tank is installed at the bottom of the heat exchanger, and the spray system is installed on the air inlet side of the heat exchanger. The spray system is connected to the water tank via a water pump, and the spray end of the spray system covers all sides of the heat exchanger.

[0009] In the above solution, fins and pipes are installed in the heat exchanger. The pipes are serpentine coils and are perpendicular to the installation surface of the fins. The liquid supply pipe of the cold source is connected to the liquid inlet pipe in the pipe, and the liquid outlet pipe in the pipe is connected to the cold source through the liquid return pipe.

[0010] In the above solution, the spray system includes a spray pipe and a plurality of nozzles, each of which is mounted at the spray end of the spray pipe. The liquid inlet pipe of the spray pipe is connected to a water pump. The liquid outlet pipe of the water pump is connected to a solid particulate matter generator, and the connecting pipe of the solid particulate matter generator is connected to the liquid inlet pipe of the spray pipe.

[0011] In the above solution, the cold source's liquid supply pipe supplies cold fluid to the heat exchanger's liquid inlet pipe. The cold fluid then exchanges heat with the gas in the heat exchanger before returning to the cold source via the return pipe. In a preferred solution, the cold fluid is either a refrigerant or a cold liquid, and the cold source is either groundwater, industrial waste cooling, or an artificial cold source.

[0012] A system for enhancing heat exchange in a gas cooling process comprises a heat exchanger, a cold source, a spray system and a water tank, and also comprises an outer shell. The heat exchanger, the spray system and the water tank are all installed in the outer shell. The cold source is installed on the top of the outer shell. One side of the outer shell is provided with an open air inlet side, and the other side of the outer shell is provided with an open air outlet side. The bottom of the water tank is connected to a drain pipe.

[0013] Compared with existing technologies, the present invention offers the following advantages: It proposes a novel method and system that forms a water film on the gas side of a gas-liquid heat exchanger, turbulently agitates the water film through spraying, and simultaneously incorporates solid particulate matter into the spray water to destabilize the boundary layer, which includes both the liquid boundary layer and the gas-liquid boundary layer. This method can effectively enhance heat transfer and significantly improve the convective heat transfer coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The disclosure of the present invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them:

[0015] Figure 1 It is a schematic diagram of the working principle of the present invention;

[0016] Figure 2 This is a schematic diagram of temperature and humidity for pure cooling of the present invention;

[0017] Figure 3 This is a schematic diagram of temperature and humidity in a dehumidification state according to the present invention.

[0018] Reference numerals in the figure: 10 - heat exchanger; 11 - fin; 12 - pipe; 20 - cold source; 21 - liquid supply pipe; 22 - liquid return pipe; 30 - spray system; 31 - spray pipe; 32 - connecting pipe; 33 - solid particulate matter generator; 34 - water pump; 40 - water tank; 41 - drain pipe; 50 - casing. DETAILED DESCRIPTION

[0019] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention will now be further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the relevant components of the present invention.

[0020] According to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art may propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific embodiments and drawings are merely illustrative of the technical solution of the present invention and should not be regarded as the entire invention or as a limitation or restriction of the technical solution of the present invention.

[0021] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0022] In the prior art, analysis has shown that the boundary layer of gas heat exchange is the main reason for the poor gas convection heat transfer performance. Therefore, the solution of this application designs a method and system that can change the heat transfer performance based on this reason.

[0023] Example 1, as Figure 1 As shown, a method for enhancing heat exchange during a gas cooling process includes a heat exchanger 10, a cold source 20, a spray system 30, and a water tank 40. The heat exchanger 10 is first connected to the cold source 20, and then the air inlet side of the heat exchanger 10 is sprayed with water through the spray system 30. The water spray accelerates the cooling of the gas flowing through the heat exchanger 10. The water spray forms a water film on the surface of the heat exchanger 10 and disturbs the water film, enhancing heat exchange between the cold fluid in the dehumidification heat exchanger tubes and the air outside the tubes, as well as mass transfer between the air and the water film. The water sprayed by the spray system 30 flows into the water tank 40, which then transports the water to the spray system 30 via a water pump 34, achieving a circulating spray.

[0024] Fins 11 and pipes 12 are installed in the heat exchanger 10, and the spray system 30 sprays the entire air inlet side, that is, the air inlet side of the pipe 12. The water sprayed on the fins 11 and the pipe 12 will flow downward due to gravity and then into the flow channel water tank 40.

[0025] Furthermore, to achieve enhanced cooling, a solid particulate matter generator 33 is installed on the connecting pipe 32 of the spray system 30. When in operation, the solid particulate matter generator 33 generates solid particulate matter, which is then sprayed across the entire air inlet side of the heat exchanger 10 by the spray system 30. The solid particulate matter disrupts the air-liquid boundary layer. Thus, through the water film disturbance and the particulate matter's disruption of the boundary layer, heat exchange between the cold fluid in the heat exchanger 10 tubes and the water film, as well as between the water film and the air outside the tubes, is enhanced.

[0026] As a preferred solution, the water spraying system 30 uses a pulsed spraying method, with the spray pressure and flow rate varying periodically. This reduces pump energy consumption and enhances water film disturbance. The solid particulate matter generated by the solid particulate matter generator 33 is nano-sized particulate matter that is insoluble or slightly soluble in water, such as zinc oxide nanoparticles and iron oxide nanoparticles.

[0027] When the present invention is used for pure refrigeration and cooling, that is, Figure 2 In the case shown, no drainage is required. When the present invention is used in a case including dehumidification and refrigeration, such as Figure 3 In the case shown, when drainage is required, Figure 1 The middle drainage pipe 41 drains water.

[0028] During implementation, a direct expansion compression system can be used to provide refrigerant as a cold source 20. When the air outlet temperature remains unchanged at 12°C, the system using this solution increases the refrigerant temperature by 4°C, that is, the refrigerant evaporation temperature is increased from 5°C in the conventional system to 9°C, and the COP of the compression system is increased by about 13%.

[0029] Example 2, based on the solution of Example 1, as Figure 1 As shown, a system for enhancing heat exchange in a gas cooling process includes a heat exchanger 10, a cold source 20, a spray system 30, and a water tank 40. The liquid supply pipe 21 of the cold source 20 is connected to the liquid inlet pipe in the heat exchanger 10, and the liquid outlet pipe in the heat exchanger 10 is connected to the cold source 20 through a liquid return pipe 22. The liquid supply pipe 21 of the cold source 20 provides cold fluid to the liquid inlet pipe in the heat exchanger 10. The cold fluid exchanges heat with the gas in the heat exchanger 10 and finally returns to the cold source 20 through the liquid return pipe 22.

[0030] As a preferred solution, the cooling fluid is any one of a refrigerant and a cooling liquid, such as R22, R134a, R407c, R410a, and R32, and the cooling liquid is ethylene glycol, ammonia water, deionized water, and the like. The cooling source 20 is any one of groundwater, industrial waste cooling, and an artificial cooling source, wherein industrial waste cooling equipment includes a chiller or a direct expansion compression refrigeration system.

[0031] A water tank 40 is installed at the bottom of the heat exchanger 10 to facilitate the recovery of sprayed water. The spray system 30 is installed on the air inlet side of the heat exchanger 10, spraying water that covers the entire side tube body and the fin surface 11. The spray system 30 is connected to the water tank 40 via a water pump 34. The spray end of the spray system 30 covers the entire side of the heat exchanger 10, cooling the entire air inlet side of the heat exchanger 10.

[0032] Heat exchanger 10 is equipped with fins 11 and pipes 12. Pipes 12 are serpentine coils and are perpendicular to the mounting surface of fins 11. A liquid supply pipe 21 of a cold source 20 is connected to the liquid inlet pipe of pipe 12. The liquid outlet pipe of pipe 12 is connected to cold source 20 via a liquid return pipe 22. When the cold fluid output from cold source 20 mixes with the gas, such as air, and is heated by heat exchange, it returns to cold source 20 through liquid return pipe 22, circulating between heat exchanger 10 and cold source 20.

[0033] In the above scheme, the spray system 30 includes a spray pipe 31 and a nozzle. There are multiple nozzles installed at the spray end of the spray pipe 31. The liquid inlet pipe of the spray pipe 31 is connected to the water pump 34, and the water in the water tank 40 is pumped by the water pump 34 to provide water for spraying.

[0034] As a preferred solution, the liquid outlet pipe of water pump 34 is connected to a solid particulate matter generator 33. The connecting pipe 32 of solid particulate matter generator 33 is connected to the liquid inlet pipe of spray pipe 31, thereby adding solid particles to the spray water. The spray water containing solid particulate matter enters heat exchanger 10, then falls into water tank 40, and then enters water pump 34, where it is discharged. The solid particulate matter generator 33 and spray system 30 thus circulate the water source containing solid particulate matter.

[0035] The solid particulate matter generator 33 can selectively release solid particulate matter into water through a control mechanism. The released solid particulate matter is micro-sized, ranging from micron to nanometer scale. The solid particulate matter is insoluble in water or slightly soluble in water, is an environmentally friendly substance, and is an inorganic substance, a metal substance, or a mixed substance.

[0036] Example 3, based on the solution of Example 2, a system for enhancing heat exchange in a gas cooling process, comprising a heat exchanger 10, a cold source 20, a spray system 30, and a water tank 40, and also comprising a housing 50. The heat exchanger 10, the spray system 30, and the water tank 40 are all installed in the housing 50, the cold source 20 is installed on the top of the housing 50, one side of the housing 50 is provided with an open air inlet side, and the other side of the housing 50 is provided with an open air outlet side. The bottom of the water tank 40 is connected to a drain pipe 41. Figure 1 As shown, external gas, such as air AI, enters the shell 50, exchanges heat with the cold fluid through the heat exchanger, and becomes AO on the air outlet side of the shell 50 and is discharged from the shell.

[0037] Figure 2 The method of the present invention is shown as being used for pure refrigeration. The dotted line from A to B in the figure represents the prior art, and the solid line from A to B in the figure represents the method of the present invention. The present invention has an accelerated cooling effect due to the effect of spraying water.

[0038] like Figure 2 As shown, the temperature can be quickly reduced. The humidified gas is then dehumidified and cooled. At the same time, the water film replaces the gas film boundary layer and the solid particulate matter destroys the boundary layer, and the convective heat transfer coefficient is greatly improved. The actual measurement shows that it is increased by 2 times, that is, the heat transfer coefficient is increased from 30w / (m 2 K) increased to 92w / (m 2 ·K).

[0039] Figure 3 The method of the present invention is shown as being used for refrigeration including dehumidification. The dotted line from A to B to C in the figure represents the prior art, and the solid line from A to B to C in the figure represents the present invention.

[0040] In the prior art, the straight line from A to B in the figure represents a completely dry cooling situation with no water precipitation, and its heat exchange effect is the worst. The straight line from B to C in the figure represents a dehumidification situation with water precipitation, and its heat exchange effect is improved. However, compared with the present invention, the heat exchange effect from B to C in the figure is only slightly improved, mainly due to the following reasons:

[0041] First, the present invention can quickly cool down due to the cooling effect of spraying water, as shown in the figure. Second, the spraying water can disturb the water film. Third, the solid particulate matter destroys the boundary layer. Compared with A to B, the main difference between B to C is that the air film boundary layer is replaced by the water film. The improvement of the convective heat transfer coefficient also comes mainly from this replacement. However, compared with the present invention, the above three differences do not bring about the cooling effect, so the improvement of the heat transfer effect is limited. According to the method of the present invention, the actual measurement shows that it is improved by more than 1.3 times, that is, the heat transfer coefficient is increased from 43w / (m 2 K) increased to 92w / (m 2 ·K).

[0042] This invention proposes a novel method and system that forms a water film on the gas side of a gas-liquid heat exchanger. This water film is then agitated by spraying. Solid particulate matter is also added to the spray water to destabilize the boundary layers, which comprise both the liquid and gas-liquid boundary layers. This method can effectively enhance heat transfer and significantly improve the convective heat transfer coefficient.

[0043] This method and system can be widely used for gas cooling in various industrial processes, such as cooling high-temperature compressed air and compressed gas, cooling gases in various heat dissipation processes, such as cooling air in data centers, and cooling air conditioning processes, such as cooling air in various process and comfort air conditioning systems. Due to the wide range of gas cooling applications and the improved high-efficiency performance of the present invention, its application will have significant energy-saving benefits and excellent economic efficiency. In addition to the efficiency gains from energy savings, it can also significantly reduce the size and cost of the heat exchanger 10, improving the economic efficiency of gas cooling.

[0044] It should be noted that, as used herein, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. These undisclosed elements are all prior art known to those skilled in the art.

[0045] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for enhancing heat exchange in a gas cooling process, characterized in that: The invention comprises a heat exchanger (10), a cold source (20), a spraying system (30) and a water tank (40), wherein the heat exchanger (10) is first connected to the cold source (20), and then the air inlet side of the heat exchanger (10) is sprayed with water through the spraying system (30), and a water film is formed on the surface of the heat exchanger (10) by the water spraying, and the water film is disturbed; the water sprayed by the spraying system (30) flows into the water tank (40), and the water tank (40) transports the water to the spraying system (30) through a water pump (34).

2. The method for enhancing heat exchange in a gas cooling process according to claim 1, characterized in that: A solid particulate matter generator (33) is installed on the connecting pipe (32) of the spray system (30). When the solid particulate matter generator (33) is in operation, solid particulate matter is generated. The solid particulate matter is sprayed onto the entire air inlet side of the heat exchanger (10) by the spray system (30), and the particulate matter destroys the gas-liquid boundary layer.

3. The method for enhancing heat exchange in a gas cooling process according to claim 2, characterized in that: The water spraying of the spraying system (30) is a pulse spraying, and the spraying pressure and flow rate change periodically; the solid particulate matter generated by the solid particulate matter generator (33) is a nano-level particulate matter, which is insoluble in water or slightly soluble in water.

4. A system for enhancing heat exchange in a gas cooling process, characterized in that: The invention comprises a heat exchanger (10), a cold source (20), a spray system (30) and a water tank (40), wherein the liquid supply pipe (21) of the cold source (20) is connected to the liquid inlet pipe in the heat exchanger (10), the liquid outlet pipe in the heat exchanger (10) is connected to the cold source (20) via a liquid return pipe (22), the water tank (40) is installed at the bottom of the heat exchanger (10), the spray system (30) is installed on the air inlet side of the heat exchanger (10), the spray system (30) is connected to the water tank (40) via a water pump (34), and the spray end of the spray system (30) covers all sides of the heat exchanger (10).

5. The system for enhancing heat exchange in a gas cooling process according to claim 4, characterized in that: The heat exchanger (10) is installed with fins (11) and pipes (12), the pipes (12) are serpentine coils and are perpendicular to the installation surface of the fins (11), the liquid supply pipe (21) of the cold source (20) is connected to the liquid inlet pipe in the pipe (12), and the liquid outlet pipe in the pipe (12) is connected to the cold source (20) via a liquid return pipe (22).

6. The system for enhancing heat exchange in a gas cooling process according to claim 4, characterized in that: The spray system (30) comprises a spray pipe (31) and a spray head. The spray heads are provided in plurality and are installed at the spray end of the spray pipe (31). The liquid inlet pipe of the spray pipe (31) is connected to a water pump (34).

7. The system for enhancing heat exchange in a gas cooling process according to claim 6, characterized in that: The liquid outlet pipe of the water pump (34) is connected to the solid particulate matter generator (33), and the connecting pipe (32) of the solid particulate matter generator (33) is connected to the liquid inlet pipe of the spray pipe (31).

8. The system for enhancing heat exchange in a gas cooling process according to claim 4, characterized in that: The liquid supply pipe (21) of the cold source (20) provides cold fluid to be transported to the liquid inlet pipe in the heat exchanger (10), and the cold fluid exchanges heat with the gas in the heat exchanger (10), and finally returns to the cold source (20) through the liquid return pipe (22).

9. The system for enhancing heat exchange during gas cooling according to claim 8, characterized in that: The cold fluid is any one of a refrigerant and a cold liquid, and the cold source (20) is any one of underground cold water, industrial waste cooling, and an artificial cold source.

10. The system for enhancing heat exchange in a gas cooling process according to claim 1, characterized in that: The invention also includes a shell (50), wherein the heat exchanger (10), the spray system (30) and the water tank (40) are all installed in the shell (50), the cold source (20) is installed on the top of the shell (50), one side of the shell (50) is provided with an open air inlet side, and the other side of the shell (50) is provided with an open air outlet side, and the bottom of the water tank (40) is connected to a drain pipe (41).

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