Drainage expansion heat recovery device

Abstract

The invention relates to the field of heat recovery devices, and provides a drainage capacity expansion heat recovery device which comprises a drainage capacity expansion device, a condensation tank, an exhaust assembly and a liquid drainage assembly. A first exhaust port is formed in the top of the drain flash tank, and a liquid outlet is formed in the bottom; a reflux inlet is formed in the bottom of the condensation tank and is higher than the first exhaust port; the exhaust assembly comprises a first exhaust pipe, a first branch pipe, a second branch pipe, a first valve and a second valve; one end of the first exhaust pipe is connected with the first exhaust port, and the other end is connected with one end of the first branch pipe and one end of the second branch pipe; the other end of the first branch pipe is communicated with the condensation tank; the first valve is arranged on the first branch pipe; the second valve is arranged on the second branch pipe; the liquid discharging assembly comprises a water pump and a flow mixing pipe; a water inlet of the water pump is communicated with the liquid outlet; the mixed flow pipe communicates with a water outlet of the water pump and the end, away from the first exhaust pipe, of the second branch pipe. The problem that cavitation is easily caused by water delivery heat recovery and water drainage is solved.

Description

Technical Field

[0001] The present application relates to the field of heat recovery devices, and in particular to a hydrophobic expansion heat recovery device. Background Art

[0002] During the start-up and shutdown of steam systems such as boilers, a large amount of high-pressure drain will be generated. The drain is usually introduced into a drain expansion tank for vapor-liquid separation. Specifically, after the drain enters the drain expansion tank, due to the sudden drop in pressure, part of the drain will flash and form steam.

[0003] At present, steam is usually discharged from the top of the hydrophobic expansion tank through a pipe. However, direct discharge of steam will not only lead to heat waste, but also produce white smoke after the steam is discharged to the outside, which reduces the public's perception. In addition, direct discharge of steam through a pipe can easily cause external gas or other impurities to enter the hydrophobic expansion tank and pollute the hydrophobic expansion tank.

[0004] If the steam is not discharged, it will easily cause cavitation in the water conveying parts. Summary of the invention

[0005] In order to solve the problem of water transfer heat recovery and cavitation easily caused by hydrophobicity, the present application provides a hydrophobicity expansion heat recovery device.

[0006] The present application provides a hydrophobic expansion heat recovery device that adopts the following technical solution: A hydrophobic expansion heat recovery device, comprising: a hydrophobic expansion container, a condensing tank, an exhaust component and a drainage component; The top of the hydrophobic expansion container is provided with a first exhaust port, and the bottom is provided with a liquid discharge port; A reflux port is provided at the bottom of the condensation tank, and the height of the reflux port is higher than the first exhaust port; The exhaust assembly includes a first exhaust pipe, a first branch pipe, a second branch pipe, a first valve and a second valve; one end of the first exhaust pipe is connected to the first exhaust port, and the other end is connected to one end of the first branch pipe and the second branch pipe respectively; the other end of the first branch pipe is connected to the condensation tank; the first valve is arranged on the first branch pipe, and the second valve is arranged on the second branch pipe; The liquid discharge assembly includes a water pump and a mixing pipe; the water inlet of the water pump is connected to the liquid discharge port; The mixing pipe is respectively connected to the water outlet of the water pump and the end of the second branch pipe away from the first exhaust pipe.

[0007] By adopting the above technical solution, the first exhaust port at the top of the hydrophobic expansion tank can discharge steam, and the drain port at the bottom is used to discharge hydrophobic water; by controlling the opening and closing of the first valve and the second valve, different heat recovery methods can be achieved. Specifically: 1. When the first valve is opened and the second valve is closed, steam enters the condensation tank for heat exchange and condensation, and then flows back into the drain expansion vessel, achieving heat recovery. Moreover, after the condensed water flows back into the drain expansion vessel, it can reduce the water temperature in the drain expansion vessel, thereby reducing the probability of cavitation in the air pump.

[0008] 2. When the first valve is closed and the second valve is opened, steam enters the second branch pipe for vapor-liquid separation. By utilizing the characteristics that a large amount of heat is carried away by the steam during the vapor-liquid separation process and the gas content of the remaining drain water in the drain expansion vessel is significantly reduced, cavitation will not be caused when the drain water in the drain expansion vessel flows through the water pump.

[0009] 3. After the drain water flows through the water pump, it remixes with steam again in the mixed flow pipe, achieving heat recovery. And there is no steam loss during the process, with a high heat recovery rate and avoiding pollution caused by external impurities.

[0010] Optionally, the drain expansion heat recovery device further includes a drain water tank, and the drain water tank is communicated with the liquid discharge port; the bottom of the drain water tank is communicated with the water inlet of the water pump.

[0011] By adopting the above technical solutions, the setting of the drain water tank can improve the stability of the system. Specifically: 1. The drain water tank temporarily stores the liquid discharged from the liquid discharge port, avoiding the possible impact or unstable flow when the liquid directly enters the water pump, thereby improving the stability of the system.

[0012] 2. The setting of the drain water tank enables the drain water separated in the drain expansion vessel to be discharged from the drain expansion vessel more quickly, minimizing the re-dissolution of gas into the drain water. And due to the water storage function of the drain water tank, the drain expansion vessel can continuously carry out drain water treatment, and the size of the drain expansion vessel does not need to be too large, which helps to reduce the cost of the drain expansion vessel.

[0013] 3. The drain water after vapor-liquid separation and the condensed water obtained after condensation in the condensation tank can be fully mixed in the drain water tank, making the temperature more uniform and reducing the probability of cavitation.

[0014] Optionally, the exhaust assembly further includes a second exhaust pipe, and the top of the drain water tank is communicated with the first exhaust pipe through the second exhaust pipe.

[0015] By adopting the above technical solutions, the drain expansion heat recovery device can discharge the small amount of steam and non-condensable gas that are not completely separated from the drain water entering the drain water tank to the first exhaust pipe by setting the second exhaust pipe at the top of the drain water tank and communicating it with the first exhaust pipe. Combining the overall design of the drain expansion vessel, condensation tank, exhaust assembly and liquid discharge assembly, this solution further optimizes the gas flow path during heat recovery, reduces energy loss, and improves the operation efficiency and reliability of the entire device.

[0016] Optionally, the condensation tank includes a tank body, a heat exchange unit, and a third valve; The top of the tank body is provided with a second exhaust port; the third valve is arranged at the second exhaust port; The heat exchange unit is arranged inside the tank body and is used for exchanging heat with the steam entering the tank body.

[0017] By adopting the above technical solution, the condensation tank can effectively recover the heat in the steam and realize the condensation of the steam. Specifically, the steam recovers heat by exchanging heat with the heat exchange component. The setting of the third valve facilitates the control of the exhaust process. When the third valve is closed, the loss of moisture can be avoided. If the steam separated during the steam-liquid separation of the hydrophobic contains non-condensable gases, the non-condensable gases can be discharged by opening the third valve.

[0018] Optionally, the heat exchange unit includes a liquid spraying main pipe, a rotating joint, and multiple liquid spraying branch pipes; The liquid spraying main pipe is vertically arranged and connected to the inner wall of the tank body; multiple liquid spraying branch pipes are arranged at intervals along the circumferential direction, and one end of each liquid spraying branch pipe is communicated with the liquid spraying main pipe through the rotating joint; The liquid spraying branch pipe is bent, and the end of the liquid spraying branch pipe far from the rotating joint rotates the liquid spraying branch pipe by spraying a first heat exchange medium.

[0019] By adopting the above technical solution, the liquid spraying main pipe is vertically arranged in the tank body, multiple liquid spraying branch pipes are arranged at intervals along the circumferential direction and are communicated with the liquid spraying main pipe through the rotating joint, and the bent liquid spraying branch pipe can rotate itself by spraying the first heat exchange medium. This design enables the liquid spraying branch pipe to expand the spraying coverage range during rotation, and the sprayed first heat exchange medium can form a curtain wall, thereby improving the heat exchange efficiency and ensuring that the steam entering the tank body can fully contact the first heat exchange medium and be quickly condensed.

[0020] Optionally, the lengths of multiple liquid spraying branch pipes are not completely the same, so that the spraying areas of the liquid spraying branch pipes with different lengths do not completely overlap.

[0021] By adopting the above technical solution, the lengths of multiple liquid spraying branch pipes not being completely the same results in the non-complete overlap of the spraying areas, which can expand the spraying coverage range of the first heat exchange medium, enhance the heat exchange effect, more fully condense the steam entering the tank body, and improve the heat recovery efficiency.

[0022] Optionally, the spraying direction of the liquid spraying branch pipe is inclined upward.

[0023] By adopting the above technical solution, the spraying direction of the liquid spraying branch pipe is towards the upper oblique direction, which can prevent the first heat exchange medium sprayed by the liquid spraying branch pipe with a shorter length from hitting the spraying branch pipe with a longer length, reducing the energy loss. Secondly, the spraying direction towards the upper oblique direction can extend the flight time of the first heat exchange medium in the air, improving the heat exchange effect.

[0024] Optionally, the heat exchange unit further includes a spiral heat exchange pipe, and a second heat exchange medium flows through the spiral heat exchange pipe.

[0025] By adopting the above technical solution, the second heat exchange medium flows through the spiral heat exchange pipe, enabling the second heat exchange medium to recover the heat of the steam. The spiral pipe shape increases the heat exchange area and heat exchange effect, enhancing the condensation efficiency of the steam, thereby improving the heat recovery capacity of the entire device.

[0026] Optionally, the water outlet end of the spiral heat exchange pipe is communicated with the main water spraying pipe.

[0027] By adopting the above technical solution, the hydrophobic expansion heat recovery device can achieve efficient heat recovery and utilization. The specific effects are as follows: 1. The water outlet end of the spiral heat exchange pipe is communicated with the main water spraying pipe, enabling the second heat exchange medium to directly enter the main water spraying pipe after heat exchange and further participate in the subsequent spraying heat exchange process. This not only improves the utilization rate of the heat exchange medium but also optimizes the energy cycle of the entire device, reducing energy loss.

[0028] 2. This design simplifies the structure of the heat exchange system, avoids the complexity of additionally setting up discharge or return pipelines, and reduces the manufacturing cost and maintenance difficulty of the device.

[0029] 3. After the liquid sprayed by the liquid spraying branch pipe falls on the spiral heat exchange pipe, it can further exchange heat with the second heat exchange medium in the spiral heat exchange pipe. On the one hand, it enables the second heat exchange medium to absorb more heat within a limited time and space; on the other hand, the liquid sprayed by the liquid spraying branch pipe can continue to exchange heat with the steam after exchanging heat with the second heat exchange medium. Through the above settings, the heat recovery efficiency is greatly improved.

[0030] Optionally, the condensation tank further includes a condensation member, and the condensation member is arranged in the second exhaust port.

[0031] By adopting the above technical solution, the condensation member can further condense the steam, preventing the steam from leaking due to insufficient condensation during the heat exchange process with the heat exchange component.

[0032] In summary, the present application includes at least one of the following beneficial technical effects: 1. By setting an exhaust assembly between the hydrophobic flash tank and the condensate tank, and using the first exhaust pipe, the first branch pipe, and the second branch pipe in cooperation with the first valve and the second valve, the steam flow direction can be flexibly adjusted, realizing different heat recovery methods; 2. The water pump in the liquid discharge assembly is combined with the mixing pipe. The liquid discharged from the hydrophobic flash tank is fully mixed with the steam in the mixing pipe only after flowing through the water pump, which not only realizes heat recovery but also reduces the probability of cavitation; 3. The spiral heat exchange pipe is combined with the liquid spraying branch pipe, greatly improving the heat recovery efficiency. Description of the Drawings

[0033] Figure 1 is a schematic structural diagram of the hydrophobic flash heat recovery device provided by this application.

[0034] Figure 2 is a schematic structural diagram of the condensate tank of the hydrophobic flash heat recovery device provided by this application.

[0035] Figure 3 is a top view of the rotary joint and the liquid spraying branch pipe provided by this application.

[0036] Description of the Reference Numerals: 1. Hydrophobic flash tank; 2. Condensate tank; 21. Tank body; 211. Return port; 212. Second exhaust port; 22. Heat exchange unit; 221. Liquid spraying main pipe; 222. Rotary joint; 223. Liquid spraying branch pipe; 224. Spiral heat exchange pipe; 23. Condensing part; 24. Third valve; 3. Drainage tank; 4. Exhaust assembly; 41. First exhaust pipe; 42. Second exhaust pipe; 43. First branch pipe; 44. Second branch pipe; 45. First valve; 46. Second valve; 5. Liquid discharge assembly; 51. Water pump; 52. Mixing pipe. Detailed Embodiments

[0037] The following further describes this application in detail Figure 1 - with reference to the Figure 3 drawings.

[0038] As Figures 1 to 2 shown, an embodiment of this application discloses a hydrophobic flash heat recovery device, including a hydrophobic flash tank 1, a condensate tank 2, a drainage tank 3, an exhaust assembly 4, and a liquid discharge assembly 5.

[0039] Specifically, the top of the hydrophobic flash tank 1 is provided with a first exhaust port, and the bottom is provided with a liquid discharge port. The liquid discharge port is communicated with the drainage tank 3 through a connecting pipe. An electromagnetic valve can be arranged on the connecting pipe.

[0040] A reflux port 211 is provided at the bottom of the tank body 21 of the condensation tank 2 , and the height of the reflux port 211 is higher than the first exhaust port.

[0041] The exhaust assembly 4 includes a first exhaust pipe 41, a second exhaust pipe 42, a first branch pipe 43, a second branch pipe 44, a first valve 45 and a second valve 46. One end of the first exhaust pipe 41 is connected to the first exhaust port, and the other end is connected to one end of the first branch pipe 43 and the second branch pipe 44 respectively; the other end of the first branch pipe 43 is connected to the condensation tank 2; the first valve 45 is provided on the first branch pipe 43, and the second valve 46 is provided on the second branch pipe 44; The liquid discharge assembly 5 includes a water pump 51 and a mixing pipe 52. The water inlet of the water pump 51 is connected to the bottom of the drain tank 3. The mixing pipe 52 is connected to the water outlet of the water pump 51 and the end of the second branch pipe 44 away from the first exhaust pipe 41.

[0042] When the drain enters the drain expansion tank 1, due to the pressure reduction, a part of the drain will flash and become steam and separate from the remaining drain. The remaining drain flows into the drain tank 3, and the remaining drain can be transported to the heat-using equipment through the water pump 51. The steam enters the first exhaust pipe 41. It should be noted that there may be a small amount of steam in the drain tank 3, and this part of the steam can enter the first exhaust pipe 41 through the second exhaust pipe 42. Since the first exhaust pipe 41 is connected to the first branch pipe 43 and the second branch pipe 44 respectively. Therefore, the user can change the flow direction of the steam by controlling the opening and closing of the first valve 45 and the second valve 46.

[0043] Specifically, when the first valve 45 is opened and the second valve 46 is closed, the steam enters the condensation tank 2. The condensation tank 2 includes a tank body 21, a heat exchange unit 22, a condensation element 23 and a third valve 24. The heat exchange unit 22 is arranged inside the tank body 21, and the heat exchange component recovers the heat of the steam by exchanging heat with the steam entering the tank body 21. After the heat exchange, the steam becomes condensed water and flows back to the drain expansion tank 1 and the drain tank 3.

[0044] A second exhaust port 212 is provided on the top of the tank body 21, and a third valve 24 is provided at the second exhaust port 212. If the separated steam contains non-condensable gases (such as oxygen, carbon dioxide, etc.), and the user wishes to discharge the non-condensable gases, the third valve 24 can be opened to discharge the non-condensable gases. The condensation element 23 is provided in the second exhaust port 212. If the steam is not completely condensed during the heat exchange process with the heat exchange unit 22, the steam may be discharged from the second exhaust port 212, resulting in water and heat loss. By providing the condensation element 23, the steam can be fully condensed to avoid the above-mentioned hidden dangers. Among them, the condensation element 23 can be a condensation plate, and the condensation plate has air holes, and a filter can be provided at the air holes.

[0045] Since the drainage is a gas-liquid two-phase flow and the temperature is relatively high. If the drainage directly flows through the water pump 51, it may cause cavitation in the water pump 51. By using the drainage expansion vessel 1 to separate the gas and liquid of the drainage, the steam takes away a large amount of heat and then becomes condensate and flows back into the drainage tank 3, reducing the gas content and the total water temperature of the drainage in the drainage tank 3, and reducing the probability of cavitation occurrence.

[0046] When the first valve 45 is closed and the second valve 46 is opened, the steam enters the second branch pipe 44. Due to the gas-liquid separation and the steam taking away a large amount of heat, the probability of cavitation occurring in the drainage in the drainage tank 3 when flowing through the water pump 51 is greatly reduced. After the drainage flows through the water pump 51, the drainage and the steam are remixed in the mixing pipe 52. The steam does not leak and the heat loss rate is low, and the heat can be fully recovered. Then, under the action of the water pump 51, the steam is dissolved in the drainage and is transported to the heat-using equipment along with the drainage. Among them, the mixing pipe 52 can be a Venturi tube. The steam is sucked in by the rapid flow of the drainage and the steam is fully mixed with the drainage.

[0047] As Figures 2 to 3 shown, in some embodiments, the heat exchange unit 22 includes a liquid spraying main pipe 221, a rotating joint 222, and a plurality of liquid spraying branch pipes 223.

[0048] The liquid spraying main pipe 221 is vertically arranged and connected to the inner wall of the tank body 21. The rotating joint 222 is connected to the top of the liquid spraying main pipe 221. A plurality of liquid spraying branch pipes 223 are arranged at intervals in the circumferential direction, and one end of each liquid spraying branch pipe 223 is communicated with the liquid spraying main pipe 221 through the rotating joint 222. By introducing the first heat exchange medium into the liquid spraying main pipe 221, the first heat exchange medium can be sprayed out from the end of the liquid spraying branch pipe 223 far away from the rotating joint 222, so as to exchange heat with the steam. After the steam becomes condensate, it flows back into the drainage tank 3 together with the first heat exchange medium. Among them, the first heat exchange medium can be demineralized water. The demineralized water flows back into the drainage tank 3 together with the condensate, and can appropriately supplement the drainage tank 3.

[0049] The first heat exchange medium sprayed out by the liquid spraying branch pipe 223 is in a divergent shape, so as to increase the spraying range. The liquid spraying branch pipe 223 is bent, so that the reaction force when the end of the liquid spraying branch pipe 223 far away from the rotating joint 222 sprays the first heat exchange medium can make the liquid spraying branch pipe 223 rotate relative to the liquid spraying main pipe 221, so that the liquid spraying branch pipe 223 can spray the first heat exchange medium in all directions to form a curtain wall, ensuring that the steam can contact and exchange heat with the first heat exchange medium.

[0050] Further, the lengths of the multiple liquid spraying branch pipes 223 are not completely the same, so that the spraying areas of the liquid spraying branch pipes 223 with different lengths do not completely overlap, expanding the spraying coverage range of the first heat exchange medium and enhancing the heat exchange effect. For example, two specifications of liquid spraying branch pipes 223 can be set, and the two specifications of liquid spraying branch pipes 223 are alternately arranged in the circumferential direction.

[0051] Further, the spraying direction of the liquid spraying branch pipe 223 is towards the upper oblique direction, so that the first heat exchange medium can stay in the air for a longer time, enhancing the heat exchange effect. On the other hand, spraying towards the upper oblique direction can prevent the first heat exchange medium sprayed by the shorter liquid spraying branch pipe 223 from hitting the longer liquid spraying branch pipe 223, avoiding the loss of kinetic energy of the first heat exchange medium and also avoiding interference with the rotational movement of the liquid spraying branch pipe 223.

[0052] In some other embodiments, the heat exchange unit 22 includes a spiral heat exchange tube 224, and a second heat exchange medium flows through the spiral heat exchange tube 224. When the steam contacts the spiral heat exchange tube 224, it can exchange heat with the second heat exchange medium, thereby realizing heat recovery. Wherein, the second heat exchange medium and the first heat exchange medium can be the same type of liquid or different types of liquid. The specific type of the second heat exchange medium is not forcibly limited as long as the heat recovery of the steam can be realized.

[0053] Further, the liquid spraying heat exchange method realized by the liquid spraying main pipe 221 and the liquid spraying branch pipes 223, and the heat exchange method through the spiral heat exchange tube 224 and the second heat exchange medium can be used in combination to enhance the heat exchange effect.

[0054] For example, both the first heat exchange medium and the second heat exchange medium can be desalted water. The water outlet end of the spiral heat exchange tube 224 is communicated with the water spraying main pipe. By introducing desalted water into the spiral heat exchange tube 224, the desalted water absorbs the heat of the steam when flowing through the spiral heat exchange tube 224. Subsequently, the desalted water enters the liquid spraying main pipe 221 and is finally sprayed out through the liquid spraying branch pipes 223 to further absorb the heat of the steam.

Claims

1. A hydrophobic expansion heat recovery device, characterized in that include: A drain expansion container (1), a condensation tank (2), a drain box (3), an exhaust assembly (4) and a drainage assembly (5); The hydrophobic expansion container (1) is provided with a first exhaust port at the top and a liquid discharge port at the bottom; The drain tank (3) is in communication with the liquid discharge port; A reflux port (211) is provided at the bottom of the condensation tank (2), and the height of the reflux port (211) is higher than the first exhaust port; The exhaust assembly (4) comprises a first exhaust pipe (41), a first branch pipe (43), a second branch pipe (44), a first valve (45) and a second valve (46); one end of the first exhaust pipe (41) is connected to the first exhaust port, and the other end is respectively connected to one end of the first branch pipe (43) and one end of the second branch pipe (44); the other end of the first branch pipe (43) is in communication with the condensation tank (2); the first valve (45) is arranged on the first branch pipe (43), and the second valve (46) is arranged on the second branch pipe (44); The liquid discharge assembly (5) comprises a water pump (51) and a mixing pipe (52); the water inlet of the water pump (51) is connected to the bottom of the drain tank (3); The mixing pipe (52) is respectively connected to the water outlet of the water pump (51) and an end of the second branch pipe (44) facing away from the first exhaust pipe (41); The condensation tank (2) comprises a tank body (21), a heat exchange unit (22) and a third valve (24); A second exhaust port (212) is provided on the top of the tank body (21); the third valve (24) is provided at the second exhaust port (212); The heat exchange unit (22) is arranged inside the tank body (21) and is used to exchange heat with the steam entering the tank body (21); The heat exchange unit (22) comprises a liquid spraying main pipe (221), a rotating joint (222), and a plurality of liquid spraying branch pipes (223); The liquid spraying main pipe (221) is arranged vertically and connected to the inner wall of the tank body (21); a plurality of liquid spraying branch pipes (223) are arranged at intervals along the circumferential direction and one end of each of the liquid spraying branch pipes (223) is connected to the liquid spraying main pipe (221) via the rotating joint (222); the rotating joint (222) is connected to the top of the liquid spraying main pipe (221); The liquid spray branch pipe (223) is bent, and one end of the liquid spray branch pipe (223) away from the rotating joint (222) sprays a first heat exchange medium to rotate the liquid spray branch pipe (223); The heat exchange unit (22) further comprises a spiral heat exchange tube (224), wherein a second heat exchange medium flows in the spiral heat exchange tube (224); The first heat exchange medium and the second heat exchange medium are both desalted water; The water outlet end of the spiral heat exchange tube (224) is in communication with the liquid spray main pipe (221).

2. The hydrophobic expansion heat recovery device according to claim 1, wherein: The exhaust assembly (4) further comprises a second exhaust pipe (42), and the top of the drain tank (3) is connected to the first exhaust pipe (41) via the second exhaust pipe (42).

3. The hydrophobic expansion heat recovery device according to claim 1, characterized in that: The lengths of multiple said liquid spraying branch pipes (223) are not completely the same, so that the spraying areas of the liquid spraying branch pipes (223) with different lengths do not completely overlap.

4. The hydrophobic expansion heat recovery device according to claim 3, wherein: The spraying direction of the said liquid spraying branch pipe (223) is towards the upper oblique direction.

5. The hydrophobic expansion heat recovery device according to claim 1, characterized in that: The said condensation tank (2) further includes a condensation member (23), and the condensation member (23) is arranged in the second exhaust port (212).

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