A direct contact heat exchanger

Abstract

The application provides a direct contact heat exchanger, which comprises a heat exchange cavity, a liquid collecting tank and a liquid supply tank, the liquid collecting tank is arranged at the bottom of the heat exchange cavity, the liquid supply tank is internally provided with a liquid pump, the lower part of one side of the heat exchange cavity is provided with an air inlet, and the top of the heat exchange cavity is provided with an air outlet; a plurality of heat exchange mechanisms are arranged in the heat exchange cavity, the plurality of heat exchange mechanisms divide the heat exchange cavity into a plurality of connected heat exchange channels, the inlet of the first-stage heat exchange channel is connected with the air inlet, and the outlet of the last-stage heat exchange channel is connected with the air outlet; the tail end of the heat exchange mechanism is connected with the liquid collecting tank, the heat exchange mechanism is provided with a spray head, and the spray head is connected with the liquid pump. By arranging the plurality of heat exchange channels in the heat exchange cavity, the length of the gas path and the contact time with the cold liquid are increased, and the equipment volume is reduced; when the gas in the heat exchange channel contacts the cold liquid sprayed by each spray head, the cold liquid is at the lowest temperature, so that the temperature difference between the gas and the cold liquid in the heat exchange channel is always maximized, and the heat exchange efficiency is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of heat exchangers, and more specifically, to a direct contact heat exchanger. Background Technology

[0002] A heat exchanger, also known as a heat exchange device or heat exchange equipment, is a device used to transfer heat from a hot fluid to a cold fluid to meet specified process requirements. It is an industrial application of convective heat transfer and heat conduction. A direct contact heat exchanger, also called a mixing heat exchanger, is a device where hot and cold fluids exchange heat through direct contact. Typically, one fluid is a gas, and the other is a liquid with a low vapor pressure, and they easily separate after heat exchange. Compared to indirect contact heat exchangers, direct contact heat exchangers have advantages such as less corrosion, no scaling, high heat exchange efficiency, small temperature difference, low pressure drop, and low investment cost. However, they also have some significant disadvantages. For example, because the two media are in direct contact, they must be immiscible and not react with each other; otherwise, contamination will occur.

[0003] Existing direct-contact heat exchangers typically employ several nozzles within the heat exchange chamber to spray a cooling fluid medium, such as water, from a height, causing it to fall downwards. Gas flows upwards from the bottom, exchanging heat. However, because the cooling fluid medium falling from a height initially contacts the lower portion, the temperature difference between the lower and upper parts of the sprayed cooling fluid medium is not maximized, resulting in relatively low heat exchange efficiency. Furthermore, due to the rapid gas flow, the heat exchange chamber is generally large to ensure effective heat exchange, occupying significant space. Uneven gas flow distribution means that some areas of the cooling fluid medium may not have sufficient or no contact with the gas, leading to low heat exchange utilization of the cooling fluid medium. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention proposes a direct contact heat exchanger.

[0005] A direct contact heat exchanger includes a heat exchange chamber, a liquid collection tank, and a liquid supply tank. The liquid collection tank is located at the bottom of the heat exchange chamber, and a liquid pump is installed in the liquid supply tank. An air inlet is located on the lower part of one side of the heat exchange chamber, and an air outlet is located at the top of the heat exchange chamber. Multiple heat exchange mechanisms are installed inside the heat exchange chamber, dividing the heat exchange chamber into interconnected multi-stage heat exchange channels. The inlet of the first-stage heat exchange channel is connected to the air inlet, and the outlet of the last-stage heat exchange channel is connected to the air outlet. The end of each heat exchange mechanism is connected to the liquid collection tank, and a nozzle is installed on each heat exchange mechanism, with the nozzle connected to the liquid pump.

[0006] Based on the above, the heat exchange mechanism includes a baffle plate disposed on the inner wall of the heat exchange chamber, a flow-collecting groove disposed at the top of the baffle plate at an incline, and a flow-collecting port disposed at the end of the flow-collecting groove; a flow-collecting pipe is disposed in the inner wall of the heat exchange chamber, one end of the flow-collecting pipe is connected to the flow-collecting port, and the other end of the flow-collecting pipe is connected to the liquid collection tank.

[0007] Based on the above, the nozzle is disposed on the top of the baffle plate and faces upward; a liquid supply pipe is correspondingly disposed inside the baffle plate and the heat exchange chamber, and the liquid supply pipe connects the liquid pump and the nozzle.

[0008] Based on the above, each of the baffle plates is provided with multiple nozzles, and the multiple nozzles are arranged at different upward angles.

[0009] Based on the above, among the nozzles provided on each of the baffle plates, the nozzles furthest from the confluence port are positioned toward the connection port of the adjacent two-stage heat exchange channels.

[0010] Based on the above, there are multiple heat exchange cavities, and the multiple heat exchange cavities are arranged in parallel.

[0011] Based on the above, the system includes a gas collection hood, one end of which is provided with a gas collection port, and the opening at the other end of the gas collection hood is connected to the air inlets of multiple heat exchange chambers.

[0012] Based on the above, the lower part of the liquid collection tank is provided with a drain port, and the upper part of the liquid supply tank is provided with a liquid inlet.

[0013] This invention has outstanding substantive features and significant progress compared to the prior art. Specifically, by setting up multi-stage heat exchange channels in the heat exchange chamber, this invention increases the length of the gas path and the contact time with the cold liquid while reducing the size of the equipment. The multiple nozzles set in the heat exchange channels ensure that the cold liquid is at its lowest temperature when the gas comes into contact with the cold liquid sprayed by each nozzle in the heat exchange channel. This keeps the temperature difference between the gas and the cold liquid in contact in the heat exchange channel at its maximum, effectively improving the heat exchange efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention.

[0015] Figure 2 This is a side view of the internal structure of the heat exchange cavity of the present invention.

[0016] Figure 3 This is a schematic diagram of the baffle plate of the present invention.

[0017] Explanation of reference numerals in the attached drawings: 1. Liquid collection tank; 2. Gas collection hood; 3. Gas collection port; 4. Heat exchange chamber; 5. Liquid inlet; 6. Gas outlet; 7. Liquid supply tank; 8. Liquid drain; 9. Gas inlet; 10. Baffle plate; 11. Manifold; 12. Manifold groove; 13. Nozzle. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figures 1-3 As shown, a direct contact heat exchanger includes a heat exchange chamber 4, a liquid collection tank 1, and a liquid supply tank 7. The liquid collection tank 1 is located at the bottom of the heat exchange chamber 4, and a liquid pump is installed in the liquid supply tank 7. An air inlet 9 is located on the lower part of one side of the heat exchange chamber 4, and an air outlet 6 is located at the top of the heat exchange chamber 4. Multiple heat exchange mechanisms are installed inside the heat exchange chamber 4, which divide the heat exchange chamber 4 into interconnected multi-stage heat exchange channels. The inlet of the first-stage heat exchange channel is connected to the air inlet 9, and the outlet of the last-stage heat exchange channel is connected to the air outlet 6. The end of each heat exchange mechanism is connected to the liquid collection tank 1, and a nozzle 13 is installed on the heat exchange mechanism, which is connected to the liquid pump.

[0020] In practice, the lower part of the liquid collection tank 1 is provided with a drain port 8, and the liquid supply tank 7 is located on one side or top of the heat exchange chamber 4. The liquid supply tank 7 is provided with a liquid inlet 5, through which cold liquid is supplied into the liquid supply tank 7. The heat exchange channel is formed between the two adjacent baffles 10 and the inner wall of the heat exchange chamber 4. In use, high-temperature gas enters the heat exchange chamber 4 through the air inlet 9 and enters the heat exchange channel. The liquid pump operates to spray the cold liquid in the liquid supply tank 7 into the heat exchange channel through the nozzle 13. The gas and the sprayed cold liquid directly contact each other for heat exchange. After heat exchange, the sprayed cold liquid falls and flows into the liquid collection tank 1, and is finally discharged through the drain port 8.

[0021] Specifically, the heat exchange mechanism includes baffles 10 disposed on the inner wall of the heat exchange chamber 4. A confluence channel 12 is inclinedly disposed at the top of the baffles 10, and a confluence port 11 is disposed at the end of the confluence channel 12. A confluence pipe is disposed in the inner wall of the heat exchange chamber 4, with one end connected to the confluence port 11 and the other end connected to the liquid collection tank 1. The front and rear sides and the left or right end of the baffles 10 are respectively in contact with the inner wall of the heat exchange chamber 4, and the remaining right or left end forms a flow opening between adjacent baffles 10, i.e., a connection opening between two stages of heat exchange channels. The nozzle 13 is disposed on the top of the baffles 10 and faces upwards. A liquid supply pipe is disposed inside the baffles 10 and the heat exchange chamber 4, and the liquid supply pipe connects to the liquid pump and the nozzle 13. The liquid pump injects coolant through nozzle 13 into the heat exchange channel, where it directly contacts the gas for heat exchange. The coolant then falls into the manifold 12. Since one end of the manifold 12 is higher than the other, the coolant flowing into it converges at the lower end and enters the manifold pipe through the manifold port 11, ultimately flowing into the collection tank 1. The nozzles 13 are upward-facing, spraying liquid upwards. Under the influence of gravity and reflection from the bottom of the baffle plate 10, the coolant descends, ensuring that the coolant from each nozzle 13 contacts the gas twice for heat exchange, thus improving the contact efficiency and utilization efficiency between the coolant and the gas. Furthermore, since each nozzle 13 is supplied with liquid by the liquid pump, the temperature of the coolant sprayed from each nozzle 13 is the initial temperature of the coolant. This means that the gas contacts the lowest temperature coolant throughout the entire heat exchange channel process, maximizing the temperature difference between the gas and the coolant, significantly improving heat exchange efficiency. Furthermore, the multi-stage heat exchange channel, achieved through the baffle plate 10, effectively extends the gas heat exchange flow, preventing low heat exchange efficiency caused by short contact time between the gas flow rate and the coolant due to high gas velocity. Simultaneously, the small size and multiple stages of the heat exchange channel reduce the overall volume of the heat exchanger, avoiding the need for large space occupation. In practical applications, fans are installed at the outlet 6 to prevent gas from being obstructed within the heat exchange channel and affecting airflow velocity.

[0022] In practice, each baffle plate 10 is equipped with multiple nozzles 13, which are spaced apart at different upward angles. The nozzles 13 on each baffle plate 10 are all angled upwards at different angles to maximize coverage of the heat exchange channel, ensuring that the gas can have as much complete contact with the coolant as possible within each heat exchange channel, thereby further improving heat exchange efficiency. In practice, among the nozzles 13 on each baffle plate 10, the nozzles 13 furthest from the confluence port 11 are positioned towards the connection port between adjacent heat exchange channels. The gas in one heat exchange channel passes through the connection port when entering the next heat exchange channel; positioning the nozzles towards the connection port further ensures the contact area and coverage of the coolant with the gas. In this embodiment, each baffle plate 10 has at least three nozzles 13, with the first two nozzles facing different angles, and the third nozzle facing the connection port.

[0023] Preferably, there are multiple heat exchange chambers 4, which are arranged in parallel. In this embodiment, the heat exchanger also includes a gas collection hood 2, one end of which is provided with a gas collection port 3, and the opening at the other end of the gas collection hood 2 is respectively connected to the air inlets 9 of multiple heat exchange chambers 4. Because the radial dimension of the heat exchange channel is set within a limited range according to the nozzle 13 to ensure the contact surface and coverage of the sprayed coolant with the gas, a large gas volume may affect the ventilation rate. In this embodiment, after the gas enters the gas collection hood 2 through the gas collection port 3, it flows into different heat exchange chambers 4, where parallel heat exchange is performed, ensuring both ventilation rate and heat exchange efficiency. In practice, when a fan is used at the outlet of the heat exchange chamber, a single gas collection hood is also employed. Figure 1 (Not shown in the image), the opening at the other end of the gas collection hood is connected to the air outlets of multiple heat exchange chambers, and the gas collection port at one end of the gas collection hood is used to connect to a ventilation fan.

[0024] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A direct contact heat exchanger, characterized in that: The device includes a heat exchange chamber, a liquid collection tank, and a liquid supply tank. The liquid collection tank is located at the bottom of the heat exchange chamber, and a liquid pump is installed in the liquid supply tank. An air inlet is located on the lower side of the heat exchange chamber, and an air outlet is located at the top of the heat exchange chamber. Multiple heat exchange mechanisms are installed within the heat exchange chamber, dividing it into interconnected multi-stage heat exchange channels. The inlet of the first-stage heat exchange channel is connected to the air inlet, and the outlet of the last-stage heat exchange channel is connected to the air outlet. The end of each heat exchange mechanism is connected to the liquid collection tank. A nozzle is installed on each heat exchange mechanism, positioned on top of a baffle plate and facing upwards, and connected to the liquid pump. Each heat exchange mechanism includes a baffle plate on the inner wall of the heat exchange chamber. A confluence channel is inclined at the top of the baffle plate, and a confluence port is located at the end of the confluence channel. A confluence pipe is installed in the inner wall of the heat exchange chamber, with one end connected to the confluence port and the other end connected to the liquid collection tank. In each of the baffle plates, the nozzles furthest from the confluence port are positioned toward the connection port of the two adjacent heat exchange channels. The front and rear sides and the left or right end of the baffle plate are respectively in contact with the inner wall of the heat exchange cavity. The remaining right or left end forms a flow port between the adjacent baffle plates, which is also the connection port of the two heat exchange channels.

2. The direct contact heat exchanger according to claim 1, characterized in that: The baffle and heat exchange chamber are equipped with corresponding liquid supply pipes, which are connected to the liquid pump and the nozzle.

3. The direct contact heat exchanger according to claim 1, characterized in that: Each of the baffle plates is provided with multiple nozzles, which are spaced apart at different upward angles.

4. The direct contact heat exchanger according to claim 1, characterized in that: There are multiple heat exchange chambers, which are arranged side by side.

5. The direct contact heat exchanger according to claim 1, characterized in that: It includes a gas collection hood, one end of which is provided with a gas collection port, and the opening at the other end of the gas collection hood is connected to the air inlets of multiple heat exchange chambers.

6. The direct contact heat exchanger according to claim 1, characterized in that: The lower part of the liquid collection tank is provided with a drain port, and the upper part of the liquid supply tank is provided with a liquid inlet.

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