Deaerator dead steam recycling device for boiler

Abstract

The utility model discloses a deaerator dead steam recycling device for a boiler, which relates to the technical field of dead steam recycling, and particularly comprises a first recycling structure and a second recycling structure, and a gas-steam separation structure and a heat recycling structure are arranged in an inner cavity of the first recycling structure. The gas-steam separation structure comprises a vacuum pump fixedly connected with the outer surface of the first recovery structure and a semi-permeable membrane fixed to the middle of an inner cavity of the first recovery structure. According to the deaerator dead steam recycling device for the boiler, separation of water vapor and waste gas in dead steam is achieved through the gas-steam separation structure, heat and condensed water in the water vapor are recycled through the heat recycling structure, heat in the waste gas is recycled through the second recycling structure, and recycling of the dead steam of the deaerator is achieved; desalted water and water vapor directly exchange heat, the heat recovery efficiency of the water vapor is improved, waste gas and the desalted water indirectly exchange heat, and the waste gas is prevented from being dissolved in the desalted water.

Description

Technical Field

[0001] The utility model relates to the technical field of exhaust steam recovery and utilization, in particular to an exhaust steam recovery and utilization device for a boiler deaerator. Background Art

[0002] In industrial production, in order to prevent and reduce the corrosion of boiler feed water pipes, economizers and other auxiliary equipment, deaerators are usually used to remove dissolved oxygen in boiler water. The deoxygenation method of boiler feed water is usually thermal deoxygenation. The feed water is heated to the saturation temperature corresponding to the working pressure of the deaerator to remove oxygen and other gases dissolved in the feed water. However, the thermal deaerator is inevitably accompanied by steam discharge in the process of exhaust gas discharge. Since the discharged steam contains a high latent heat, it causes energy loss and clean water loss. The external discharge of "Little White Dragon" affects the corporate image. In winter, the exhaust steam discharged will condense into water and freeze on the ground, affecting the walking of the operators. There are certain safety hazards. The gas and water are discharged together, the flow rate is large, and a large noise is generated. Water vapor condenses on equipment and frames in colder weather. If there is a corrosive medium in the air, it combines with condensed water to form acid or alkali, causing serious corrosion to steel structures and equipment.

[0003] Generally speaking, the exhaust steam recovery of deaerator is divided into steam recovery and hot water recovery. Steam recovery is to increase the pressure of exhaust steam of deaerator and integrate it into the steam network for use. This scheme consumes the power of high-quality steam when used, and the volume of waste gas in exhaust steam is relatively large. The exhaust steam needs to be pressurized to induce exhaust steam, resulting in serious energy waste, and the exhaust gas will corrode the steam network, bringing huge risk factors to the steam network; There are currently two schemes for hot water recovery of exhaust steam of deaerator on the market, one is to condense exhaust steam into water by using jet mixing condenser, and the other is to condense steam into water by using membrane condenser. The main disadvantage of exhaust steam recovery by jet mixing condenser is that the latent heat of exhaust steam is high, which causes water hammer and system vibration during the heat transfer process in the mixer, and the scale of exhaust steam recovery is limited. This exhaust steam recovery facility is the mainstream design on the market. The exhaust steam of one deaerator corresponds to one Venturi mixer. The price of exhaust steam recovery of a single deaerator is about 400,000 yuan. Adding a Venturi will increase the price by more than 100,000 yuan, which is a high investment. The main disadvantage of using a membrane condenser to recover exhaust steam is that the exhaust steam and desalted water exchange heat indirectly, and there is more non-condensable gas in the exhaust gas discharged from the deaerator, which affects the heat transfer coefficient. The heat exchange equipment is large, and the temperature of exhaust steam recovery is around 100°C. At this temperature, if the circulating water heat exchanger is used for heat exchange, scaling will be serious, and only clean water can be selected as the cooling medium.

[0004] In summary, it is urgently needed in the art to design a boiler deaerator exhaust steam recovery device with a simple structure and good exhaust steam recovery effect. Utility Model Content

[0005] The utility model provides a boiler deaerator exhaust steam recovery device, which solves the problems of high energy consumption, low efficiency and high investment cost of common deaerator exhaust steam recovery process technology and equipment proposed in the above background technology.

[0006] The utility model provides the following technical solutions: a boiler deaerator exhaust steam recovery and utilization device, comprising a first recovery structure and a second recovery structure, wherein the inner cavity of the first recovery structure is provided with a gas-steam separation structure and a heat recovery structure, wherein the gas-steam separation structure comprises a vacuum pump fixedly connected to the outer surface of the first recovery structure and a semipermeable membrane fixed to the middle of the inner cavity of the first recovery structure, wherein the top of the semipermeable membrane is provided with an exhaust steam input pipe, the bottom of the semipermeable membrane is fixedly connected with an exhaust gas output pipe, the other end of the exhaust gas output pipe is fixedly connected to the bottom of the inner cavity of the second recovery structure, the air inlet end of the vacuum pump extends to the inner cavity of the first recovery structure through a vacuum pipe, and a pressure detector is fixed to the inner wall of the first recovery structure; the heat recovery structure comprises a collection box fixed to the bottom of the first recovery structure, a liquid outlet pipe fixedly connected to the bottom of the collection box, and a spray ring, an inner heat exchange ring and an outer heat exchange ring arranged in the inner cavity of the first recovery structure, wherein the semipermeable membrane, the spray ring, the inner heat exchange ring and the outer heat exchange ring are sequentially arranged in the inner cavity of the first recovery structure;

[0007] A diverter box is fixed at the bottom of the inner cavity of the second recovery structure, and the other end of the exhaust gas output pipe extends into the inner cavity of the diverter box. A junction box is fixed at the top of the second recovery structure, and an exhaust pipe is fixed at the top of the junction box. The diverter box and the junction box are connected via a heat exchange tube. A spray ring 2 is fixed at the top of the second recovery structure, and a liquid outlet pipe 2 is provided on one side of the bottom of the second recovery structure.

[0008] Preferably, a desalted water inlet pipe 1 is provided on one side of the top of the inner cavity of the spray ring 1, and a desalted water inlet pipe 2 is fixed on one side of the top of the inner cavity of the spray ring 2.

[0009] Preferably, an isolation net ring is fixed to the top of the inner heat exchange ring, the top of the isolation net ring is fixedly connected to the top of the inner cavity of the first recovery structure, and the height of the isolation net ring is not greater than the distance between the bottom of the spray ring 1 and the top of the first recovery structure, and the bottom end of the inner heat exchange ring is located below the semipermeable membrane; a desalted water inlet pipe 4 is fixed to one side of the top of the inner cavity of the inner heat exchange ring, and a drainage hole is provided on one side of the bottom of the inner heat exchange ring.

[0010] Preferably, the outer heat exchange ring is located above the collecting box, the top of the outer heat exchange ring is fixedly connected to the top of the inner cavity of the first recovery structure, a desalted water inlet pipe three is provided on one side of the top of the inner cavity of the outer heat exchange ring, and a drainage hole is provided on one side of the bottom of the inner cavity of the outer heat exchange ring.

[0011] Preferably, the pressure detector and the end of the vacuum tube away from the vacuum pump are both located outside the outer heat exchange ring, an electric ball valve is provided at one end of the vacuum tube, and a dehumidification block is fixed to the end of the vacuum tube away from the vacuum pump.

[0012] Preferably, outer surfaces of both the exhaust steam input pipe and the waste gas output pipe are wrapped with a heat insulation sleeve.

[0013] Preferably, a thermal pad is fixed to the inner wall of the heat exchange tube, and thermal fins are evenly fixed to the outer surface of the heat exchange tube, and the thermal fins are in contact with the thermal pad.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] 1. The boiler deaerator exhaust steam recovery device utilizes a gas-steam separation structure to separate water vapor from exhaust gas, recovers heat and condensed water in water vapor through a heat recovery structure, and then recovers heat in exhaust gas through a second recovery structure to achieve the recovery of deaerator exhaust steam. When the device is in use, desalted water and water vapor are directly exchanged for heat to improve the water vapor heat recovery efficiency, while exhaust gas and desalted water are indirectly exchanged for heat to avoid exhaust gas dissolving in desalted water.

[0016] 2. The exhaust steam recovery device of the boiler deaerator, through the setting of heat exchange tubes, the heat in the exhaust gas is exchanged with the desalted water through the thermal pads and heat dissipation fins, avoiding the exhaust gas from corroding the heat exchange tubes and prolonging the service life of the heat exchange tubes; through the setting of the inner heat exchange ring and the outer heat exchange ring, the sprayed desalted water and water vapor can be intercepted, reducing the influence of water vapor on the vacuum pump, which is convenient for the operation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a front view of the structure of the utility model;

[0018] Figure 2 The utility model structure Figure 1 Back side diagram;

[0019] Figure 3 The utility model structure Figure 1 Bottom schematic diagram;

[0020] Figure 4 This is a schematic diagram of the interior of the first recovery structure of the utility model;

[0021] Figure 5 This is a schematic diagram of the interior of the second recovery structure of the utility model.

[0022] In the figure: 1. first recovery structure; 2. second recovery structure; 3. exhaust steam input pipe; 4. exhaust gas output pipe; 5. spray ring one; 6. desalted water inlet pipe one; 7. vacuum pump; 8. vacuum pipe; 9. spray ring two; 10. exhaust pipe; 11. desalted water inlet pipe three; 13. liquid outlet pipe two; 14. desalted water inlet pipe two; 15. liquid outlet pipe one; 16. desalted water inlet pipe four; 17. pressure detector; 18. isolation mesh ring; 19. external heat exchange ring; 20. semipermeable membrane; 21. internal heat exchange ring; 22. collection box; 23. heat exchange tube; 24. diverter box. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] The utility model provides a boiler deaerator exhaust steam recovery and utilization device, comprising a first recovery structure 1 and a second recovery structure 2. A gas-steam separation structure and a heat recovery structure are arranged in the inner cavity of the first recovery structure 1, the gas-steam separation structure comprises a vacuum pump 7 fixedly connected to the outer surface of the first recovery structure 1 and a semipermeable membrane 20 fixed to the middle of the inner cavity of the first recovery structure 1, the semipermeable membrane 20 is an annular structure, an exhaust steam input pipe 3 is arranged on the top of the semipermeable membrane 20, and an exhaust gas output pipe 4 is fixedly connected to the bottom of the semipermeable membrane 20, the exhaust steam generated by the boiler deaerator during operation can enter the inner cavity of the semipermeable membrane 20 through the exhaust steam input pipe 3, and during the exhaust steam flowing in the inner cavity of the semipermeable membrane 20, water vapor can pass through the semipermeable membrane 20 to achieve separation of water vapor and exhaust gas.

[0025] The air inlet end of the vacuum pump 7 is fixedly connected to a vacuum tube 8, the other end of the vacuum tube 8 extends into the inner cavity of the first recovery structure 1, and a dehumidification block is fixed to the bottom of the other end of the vacuum tube 8. The dehumidification block can absorb moisture to prevent water vapor from entering the vacuum pump 7. In some embodiments of the present application, the dehumidification block can use activated carbon to absorb moisture. An electric ball valve is provided at one end of the vacuum tube 8, and the electric ball valve can be used to control the on and off of the inner cavity of the vacuum tube 8.

[0026] A pressure detector 17 is fixed to the inner wall of the first recovery structure 1. Through the setting of the pressure detector 17, the pressure in the inner cavity of the first recovery structure 1 can be detected, which is convenient for the vacuum pump 7 to adjust the pressure difference between the inside and outside of the semipermeable membrane 20 and increase the probability of water vapor passing through the semipermeable membrane 20.

[0027] The heat recovery structure includes a collecting box 22 fixed at the bottom of the first recovery structure 1, a liquid outlet pipe 15 fixedly connected to the bottom of the collecting box 22, and a spray ring 5, an inner heat exchange ring 21 and an outer heat exchange ring 19 arranged in the inner cavity of the first recovery structure 1. The semipermeable membrane 20, the spray ring 5, the inner heat exchange ring 21 and the outer heat exchange ring 19 are arranged in the inner cavity of the first recovery structure 1 in sequence. The semipermeable membrane 20 is located in the inner cavity of the spray ring 5, the spray ring 5 is located in the inner cavity of the inner heat exchange ring 21, the inner heat exchange ring 21 is located in the inner cavity of the outer heat exchange ring 19, and the pressure detector 17 and the end of the vacuum tube 8 away from the vacuum pump 7 are both located on the outside of the outer heat exchange ring 19.

[0028] A desalted water inlet pipe 6 is fixedly connected to one side of the top of the inner cavity of the spray ring 5, and the desalted water can enter the inner cavity of the spray ring 5 through the desalted water inlet pipe 6. Nozzles are evenly arranged at the bottom of the inner cavity of the spray ring 5. The desalted water entering the inner cavity of the spray ring 5 can be evenly sprayed into the inner cavity of the first recovery structure 1 through the nozzles. The water vapor passing through the semipermeable membrane 20 can directly exchange heat with the sprayed desalted water. The heated desalted water and condensed water fall into the inner cavity of the collection box 22 under the action of gravity, and can be discharged from the liquid outlet pipe 15 at the bottom of the collection box 22, and the discharged desalted water can be used as make-up water for the boiler deaerator.

[0029] An isolation mesh ring 18 is fixed to the top of the inner heat exchange ring 21, and the top of the isolation mesh ring 18 is fixedly connected to the top of the inner cavity of the first recovery structure 1, and the height of the isolation mesh ring 18 is not greater than the distance between the bottom of the spray ring 5 and the top of the first recovery structure 1. Through the setting of the isolation mesh ring 18, the inner heat exchange ring 21 can intercept the spray water to prevent the spray water from entering between the inner heat exchange ring 21 and the outer heat exchange ring 19.

[0030] A desalted water inlet pipe four 16 is fixed to one side of the top of the inner cavity of the inner heat exchange ring 21, and a drainage hole is provided on one side of the bottom of the inner heat exchange ring 21. Through the setting of the inner heat exchange ring 21, when the device is in use, the desalted water can enter the inner cavity of the inner heat exchange ring 21 through the desalted water inlet pipe four 16. The desalted water can exchange heat with the steam during the flow in the inner cavity of the inner heat exchange ring 21, thereby reducing the amount of steam passing through the isolation mesh ring 18. The desalted water after heat exchange falls into the collection box 22 through the drainage hole.

[0031] The outer heat exchange ring 19 is located above the collecting box 22, and the top of the outer heat exchange ring 19 is fixedly connected to the top of the inner cavity of the first recovery structure 1. A desalted water inlet pipe 3 11 is provided on one side of the top of the inner cavity of the outer heat exchange ring 19, and a drainage hole is provided on one side of the bottom of the inner cavity of the outer heat exchange ring 19. Through the setting of the outer heat exchange ring 19, desalted water can enter the inner cavity of the outer heat exchange ring 19 through the desalted water inlet pipe 3 11, and the desalted water can exchange heat with the steam between the outer heat exchange ring 19 and the inner heat exchange ring 21, so as to realize the recovery of heat and condensed water in the steam and reduce the influence of the steam on the dehumidification block.

[0032] The other end of the exhaust gas output pipe 4 is fixedly connected to the bottom of the inner cavity of the second recovery structure 2, a diverter box 24 is fixed at the bottom of the inner cavity of the second recovery structure 2, the other end of the exhaust gas output pipe 4 extends into the inner cavity of the diverter box 24, a junction box is fixed at the top of the second recovery structure 2, an exhaust pipe 10 is fixed at the top of the junction box, the diverter box 24 is connected to the junction box through a heat exchange tube 23, through the arrangement of the diverter box 24, the heat exchange tube 23 and the junction box, the exhaust gas flowing in the exhaust gas output pipe 4 can enter the heat exchange tube 23, the exhaust gas after heat exchange can enter the exhaust pipe 10 through the junction box, and be discharged through the exhaust pipe 10.

[0033] A spray ring 29 is fixed on the top of the second recovery structure 2, a liquid outlet pipe 2 13 is provided on one side of the bottom of the second recovery structure 2, and a desalted water inlet pipe 2 14 is fixed on one side of the top of the inner cavity of the spray ring 2 9. Through the setting of the spray ring 2 9, the desalted water can enter the inner cavity of the spray ring 2 9 through the desalted water inlet pipe 2 14, and the desalted water in the inner cavity of the spray ring 2 9 can be sprayed onto the heat exchange tube 23 through the nozzle provided at the bottom of the inner cavity. The desalted water and the exhaust gas can generate heat exchange, realize the recovery of heat in the exhaust gas, and avoid the exhaust gas from affecting the gas concentration in the desalted water.

[0034] A thermal pad is fixed on the inner wall of the heat exchange tube 23, and thermal fins are evenly fixed on the outer surface of the heat exchange tube 23. The thermal fins are in contact with the thermal pad. The material of the thermal pad can be high-temperature resistant thermally conductive silicone. By setting the thermal pad, the heat exchange speed between the exhaust gas and the desalted water can be increased while the exhaust gas can avoid corroding the heat exchange tube 23, thereby extending the service life of the heat exchange tube 23.

[0035] From the above description, it can be seen that when the device recycles the exhaust steam, the water vapor and the exhaust gas are first separated, and then the heat and water vapor in the exhaust gas are respectively recycled. In the process of recovering the heat of the exhaust gas, the exhaust gas and the desalted water are indirectly exchanged with each other to avoid the exhaust gas dissolving into the desalted water. When the water vapor is recycled, the desalted water is in direct contact with the water vapor to improve the heat exchange efficiency.

[0036] The outer surfaces of the exhaust steam input pipe 3 and the waste gas output pipe 4 are both wrapped with heat insulation sleeves. The heat damage during gas movement can be reduced by the provision of the heat insulation sleeves. The material of the heat insulation sleeves can be pearl cotton.

[0037] The electrical components involved in this application are all prior art, and technicians in this field are familiar with their connection methods. Through these technicians, all the electrical components in this application are connected to their compatible power supplies through wires, and according to the actual situation, a suitable controller is selected to meet the control requirements. The specific connection and control sequence are described below. The electrical connection is completed in a sequential working order, and the detailed connection means are well known in the art. The following mainly introduces the working principle and process, and no further explanation of the electrical control is given.

[0038] In summary, when the boiler deaerator exhaust steam recovery and utilization device is used, the vacuum pump 7 works, and the operation of the vacuum pump 7 makes the outer side of the semipermeable membrane 20 in a vacuum state. The exhaust steam generated when the boiler deaerator works enters the inner cavity of the semipermeable membrane 20 through the exhaust steam inlet pipe, and the water vapor in the exhaust steam passes through the semipermeable membrane 20 and enters the lower part of the spray ring 5. The water vapor and the desalted water sprayed from the spray ring 5, the desalted water flowing in the inner heat exchange ring 21, and the desalted water flowing in the outer heat exchange ring 19 can enter the inner cavity of the semipermeable membrane 20. Heat exchange is carried out, and the desalted water and condensed water after heat exchange fall into the collecting box 22 under the action of gravity. The heated desalted water in the collecting box 22 can be discharged through the liquid outlet pipe 15, and the separated exhaust gas enters the inner cavity of the heat exchange tube 23 through the exhaust gas output pipe 4. The exhaust gas in the heat exchange tube 23 exchanges heat with the desalted water sprayed by the spray ring 29, and the heated desalted water is discharged through the liquid outlet pipe 13, and the heated desalted water can be used as make-up water for the deaerator. The device realizes the recovery and utilization of exhaust steam.

[0039] The standard parts used in the utility model can be purchased from the market, and the special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt the conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt the conventional models in the prior art and will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field. Although the embodiments of the utility model have been shown and described, it can be understood by ordinary technicians in this field that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and spirit of the utility model. The scope of the utility model is defined by the attached claims and their equivalents.

Claims

1. A boiler deaerator exhaust steam recovery device, comprising a first recovery structure (1) and a second recovery structure (2), characterized in that: The inner cavity of the first recovery structure (1) is provided with a gas-steam separation structure and a heat recovery structure. The gas-steam separation structure comprises a vacuum pump (7) fixedly connected to the outer surface of the first recovery structure (1) and a semipermeable membrane (20) fixed to the middle of the inner cavity of the first recovery structure (1). The top of the semipermeable membrane (20) is provided with a waste steam input pipe (3). The bottom of the semipermeable membrane (20) is fixedly connected to a waste gas output pipe (4). The other end of the waste gas output pipe (4) is fixedly connected to the bottom of the inner cavity of the second recovery structure (2). The air inlet end of the vacuum pump (7) extends to the inner cavity of the second recovery structure (2) through a vacuum pipe (8). The heat recovery structure comprises a collection box (22) fixed to the bottom of the first recovery structure (1), a liquid outlet pipe (15) fixedly connected to the bottom of the collection box (22), a spray ring (5), an inner heat exchange ring (21) and an outer heat exchange ring (19) arranged in the inner cavity of the first recovery structure (1), and the semipermeable membrane (20), the spray ring (5), the inner heat exchange ring (21) and the outer heat exchange ring (19) are arranged in sequence in the inner cavity of the first recovery structure (1); A diverter box (24) is fixed at the bottom of the inner cavity of the second recovery structure (2), the other end of the exhaust gas output pipe (4) extends into the inner cavity of the diverter box (24), a junction box is fixed at the top of the second recovery structure (2), an exhaust pipe (10) is fixed at the top of the junction box, the diverter box (24) and the junction box are connected via a heat exchange tube (23), a spray ring 2 (9) is fixed at the top of the second recovery structure (2), and a liquid outlet pipe 2 (13) is provided on one side of the bottom of the second recovery structure (2).

2. A boiler deaerator exhaust steam recovery device according to claim 1, characterized in that: A desalted water inlet pipe (1) (6) is provided on one side of the top of the inner cavity of the spray ring (5), and a desalted water inlet pipe (14) is fixed on one side of the top of the inner cavity of the spray ring (9).

3. The boiler deaerator exhaust steam recovery device according to claim 1, characterized in that: An isolation net ring (18) is fixed on the top of the inner heat exchange ring (21), and the top of the isolation net ring (18) is fixedly connected to the top of the inner cavity of the first recovery structure (1), and the height of the isolation net ring (18) is not greater than the distance between the bottom of the spray ring (5) and the top of the first recovery structure (1), and the bottom end of the inner heat exchange ring (21) is located below the semipermeable membrane (20); a desalted water inlet pipe (16) is fixed on one side of the top of the inner cavity of the inner heat exchange ring (21), and a drainage hole is provided on one side of the bottom of the inner heat exchange ring (21).

4. The exhaust steam recovery device for a boiler deaerator according to claim 1 is characterized in that: The outer heat exchange ring (19) is located above the collection box (22), the top of the outer heat exchange ring (19) is fixedly connected to the top of the inner cavity of the first recovery structure (1), a deionized water inlet pipe three (11) is provided on one side of the top of the inner cavity of the outer heat exchange ring (19), and a drainage hole is provided on one side of the bottom of the inner cavity of the outer heat exchange ring (19).

5. The boiler deaerator exhaust steam recovery device according to claim 3, characterized in that: The pressure detector (17) and the end of the vacuum tube (8) away from the vacuum pump (7) are both located outside the outer heat exchange ring (19), an electric ball valve is provided at one end of the vacuum tube (8), and a dehumidification block is fixed to the end of the vacuum tube (8) away from the vacuum pump (7).

6. The exhaust steam recovery device of a boiler deaerator according to claim 3 is characterized in that: The outer surfaces of both the exhaust steam input pipe (3) and the waste gas output pipe (4) are wrapped with heat insulation sleeves.

7. The boiler deaerator exhaust steam recovery device according to claim 3, characterized in that: A heat-conducting pad is fixed on the inner wall of the heat exchange tube (23), and heat-conducting fins are evenly fixed on the outer surface of the heat exchange tube (23), and the heat-conducting fins are in contact with the heat-conducting pad.

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