Heat recycling unit of boiler system

Abstract

The utility model provides a heat recycling unit of a boiler system, which belongs to the technical field of heat recycling of coal-fired boilers and is structurally characterized in that a slag cooler water inlet pipe and a slag cooler water outlet pipe are arranged in a heat exchange process of a slag cooler; the tail end of the slag cooler water outlet pipe is communicated into the softened water tank; a path of dead steam recoverer water inlet pipe is shunted from the slag cooler water outlet pipe in parallel and is communicated to the tower bottom of the dead steam recoverer; the downstream of the water outlet pipe of the dead steam recoverer at the tower bottom converges and is communicated to a heating station hot water pipe; one deaerator water inlet pipe is shunted from the pipe body of the dead steam recoverer water outlet pipe to be communicated to the deaerator tank top, and the other shunted pipe is communicated to a heating station; the downstream of a condensate outlet pipe at the lower part of the tower body of the dead steam recoverer is communicated to the softened water tank; one branch of the deaerator exhaust pipe is a dead steam inlet pipe communicated to a dead steam recoverer; and the other path is communicated to a silencer. The heat recovery device effectively recovers heat of outlet water of the slag cooler, and energy is saved; the system is flexible to adjust, small in investment, high in recovered heat and high in economic benefit.

Description

Technical Field

[0001] The utility model relates to the technical field of heat recovery and utilization of coal-fired boilers, in particular to a heat recovery and utilization unit of a boiler system. Background Art

[0002] Circulating fluidized bed boiler is the most industrialized clean coal combustion technology, which is widely used in chemical industry such as synthetic ammonia and heating industry. The working principle of circulating fluidized bed boiler is that coal is transported to the combustion chamber and burned under the action of air. During the combustion process, the high-temperature flue gas is heat-exchanged with the water in the boiler water pipe through the heat exchanger, so that the water is converted into steam, which provides kinetic energy for chemical equipment or is used for heating. The high-temperature slag produced by coal combustion has a temperature of about 900℃ and needs to be cooled to room temperature before transportation and treatment.

[0003] Because oxygen dissolved in water can cause corrosion of metals in contact with water, in order to ensure the quality of circulating fluidized bed boiler feed water and avoid boiler oxygen corrosion, the boiler system is generally equipped with a deaerator. Steam is used to heat the feed water in the deaerator to increase the water temperature, so that the partial pressure of steam on the water surface gradually increases, while the partial pressure of dissolved gas gradually decreases, and the gas dissolved in the water continuously escapes. When the water is heated to the boiling temperature under the corresponding pressure, the water surface is full of water vapor. The partial pressure of dissolved gas is zero, and water no longer has the ability to dissolve gas, that is, oxygen and other non-condensable gases dissolved in water can be removed.

[0004] In traditional boiler systems, high-temperature slag is generally cooled with desalted water. After the desalted water absorbs the heat of the slag, its temperature rises and it is directly discharged into the soft water tank, wasting a lot of heat. At the same time, if this part of the high-temperature desalted water is to be recycled, it needs to be transported to the refinement section through the soft water tank for refining, purification and cooling. The high temperature will undoubtedly increase the operating load and cooling cost of the subsequent refinement section.

[0005] In traditional boiler systems, the oxygen and other non-condensable gases released by deoxidation are mixed into exhaust steam, which is usually discharged directly, and the heat in the exhaust steam is also wasted. At the same time, the deaerator water replenishment of traditional processes generally uses desalted water at room temperature. The thermal deoxidation process requires a large amount of steam to heat the desalted water to boiling, which consumes a lot of steam and has high operating costs. Summary of the invention

[0006] The technical task of the utility model is to solve the deficiencies of the prior art and provide a heat recovery and utilization unit for a boiler system.

[0007] The technical solution of the utility model is implemented in the following manner: a heat recovery unit of a boiler system of the utility model comprises a slag cooler (1), an exhaust steam recovery device (2), a deaerator (3), a heating station (4), a soft water tank (5), and a muffler (6);

[0008] A slag cooler water inlet pipe (7) and a slag cooler water outlet pipe (19) are provided in the heat exchange process of the slag cooler (1) for heat exchange;

[0009] The end of the slag cooler water outlet pipe (19) is connected to the soft water tank (5);

[0010] A water inlet pipe (8) for an exhaust steam recovery device is connected in parallel to the slag cooler water outlet pipe (19), and the end of the water inlet pipe (8) for the exhaust steam recovery device is connected to the bottom of the exhaust steam recovery device (2);

[0011] The exhaust steam recovery device outlet pipe (21) at the bottom of the exhaust steam recovery device (2) is connected downstream to the hot water pipe (23) of the heating station;

[0012] A middle part of the exhaust steam recovery device outlet pipe (21) is split into a deaerator water inlet pipe (16) connected to the top of the deaerator (3) tank, and another part is split into a heating station water inlet pipe (15) connected to the heating station (4);

[0013] The condensate outlet pipe (17) at the lower part of the tower body of the exhaust steam recovery device (2) is connected downstream to the soft water tank (5);

[0014] The middle part of the tower body of the exhaust steam recovery device (2) is connected to an exhaust steam recovery device exhaust pipe (18), and the exhaust steam recovery device exhaust pipe (18) is vented;

[0015] The deaerator (3) tank top is provided with a deaerator water supply pipe (24) and a deaerator exhaust pipe (20), and the tank bottom is provided with a deaerator water outlet pipe (25);

[0016] The exhaust pipe (20) of the deaerator is divided into two paths, one of which is the exhaust steam inlet pipe (12) connected to the top of the exhaust steam recovery device (2); and the other is the exhaust steam vent pipe (13) connected to the muffler (6);

[0017] The muffler (6) is connected to the muffler air outlet pipe (14).

[0018] A valve III (29) is provided on the water inlet pipe (8) of the exhaust steam recovery device;

[0019] A valve IV (30) is provided on the slag cooler water outlet pipe (19) downstream of the parallel flow splitting node of the slag cooler water outlet pipe (19) and the exhaust steam recovery device water inlet pipe (8);

[0020] Either valve III (29) or valve IV (30) is set to normally open, or both are set to normally open.

[0021] The pipeline configuration of the exhaust steam inlet pipe (12) and the exhaust steam vent pipe (13) connected in parallel downstream of the exhaust pipe (20) output from the top of the deaerator (3) tank is as follows:

[0022] A valve I (27) is provided on the exhaust steam inlet pipe (12);

[0023] A valve II (28) is arranged on the exhaust steam vent pipe (13).

[0024] From the outlet pipe (19) of the slag cooler used for heat exchange cooling of the slag,

[0025] Through the exhaust steam recovery device inlet pipe (8), to the bottom of the exhaust steam recovery device (2),

[0026] Through the exhaust steam recovery device outlet pipe (21), the deaerator inlet pipe (16), to the deaerator (3),

[0027] Through the exhaust pipe (20) of the deaerator, through the exhaust steam inlet pipe (12), to the top of the exhaust steam recovery device (2);

[0028] This process constitutes an open heat circulation system.

[0029] In the heat circulation system:

[0030] The downstream of the slag cooler water outlet pipe (19) is connected to the soft water tank (5) through the soft water tank inlet pipe (11);

[0031] The bottom of the soft water tank (5) is connected to a soft water tank outlet pipe (26).

[0032] The upstream of the heating station (4) is connected to a heating station steam inlet pipe (22), and the downstream is connected to a heating station hot water pipe (23);

[0033] The water flow branched from the exhaust steam recovery device outlet pipe (21) is connected downstream to the heating station hot water pipe (23) downstream of the heating station (4).

[0034] Compared with the prior art, the utility model has the following beneficial effects:

[0035] The utility model discloses a heat recovery unit for a boiler system, which can effectively recover the heat of water discharged from a slag cooler and save energy compared with a traditional boiler system.

[0036] The utility model can effectively recover the heat of the exhaust steam discharged by the deaerator and save energy.

[0037] The high-temperature desalted water produced by the system of the utility model can be directly used for heating in winter, which effectively reduces or stops the use of heating steam or directly stops the heating station, thus saving steam consumption and reducing energy consumption.

[0038] The utility model can effectively reduce the amount of steam used in the deaerator and the amount of water added to the deaerator, thereby saving energy and reducing consumption.

[0039] The utility model has the advantages of flexible adjustment, small investment, large amount of recovered heat and high economic benefit.

[0040] The utility model discloses a heat recovery unit for a boiler system, which has reasonable design, simple structure, safety and reliability, convenient use and easy maintenance, and has good value for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Attached Figure 1 It is a structural schematic diagram of the utility model.

[0042] The symbols in the accompanying drawings represent:

[0043] 1. Slag cooler; 2. Exhaust steam recovery device; 3. Deaerator; 4. Heating station;

[0044] 5. Soft water tank; 6. Muffler;

[0045] 7. Slag cooler water inlet pipe; 8. Exhaust steam recovery device water inlet pipe; 9. Slag input channel; 10. Slag output channel;

[0046] 11. Soft water tank inlet pipe; 12. Exhaust steam inlet pipe; 13. Exhaust steam vent pipe;

[0047] 14. Muffler outlet pipe;

[0048] 15. Heating station water inlet pipe; 16. Deaerator water inlet pipe; 17. Condensate outlet pipe; 18. Exhaust steam recovery device exhaust pipe; 19. Slag cooler outlet pipe; 20. Deaerator exhaust pipe; 21. Exhaust steam recovery device outlet pipe; 22. Heating station steam inlet pipe; 23. Heating station hot water pipe; 24. Deaerator water supply pipe; 25. Deaerator outlet pipe; 26. Soft water tank outlet pipe;

[0049] 27. Valve I; 28. Valve II; 29. ​​Valve III; 30. Valve IV. DETAILED DESCRIPTION

[0050] The heat recovery and utilization unit of a boiler system of the utility model is described in detail below with reference to the accompanying drawings.

[0051] As shown in the accompanying drawings, the utility model is a heat recovery and utilization unit of a boiler system, in which the inlet end of the slag cooler 1 is connected to the slag cooler water inlet pipe 7 and the slag input channel 9, and the outlet end is connected to the slag cooler water outlet pipe 19 and the slag output channel 10; in the slag cooler, low-temperature desalted water and high-temperature slag exchange heat, and the slag temperature is reduced to room temperature before being transported and processed, and the desalted water absorbs the heat of the slag and the temperature rises before entering the exhaust steam recovery device 3 or the soft water tank 5.

[0052] The inlet end of the exhaust steam recovery device 2 is connected to the exhaust steam inlet pipe 12 and the exhaust steam recovery device water inlet pipe 8, and the outlet end is connected to the condensate outlet pipe 17, the exhaust steam recovery device water outlet pipe 21, and the exhaust steam recovery device exhaust pipe 18; in the exhaust steam recovery device, the desalted water from the slag cooler and the exhaust steam from the deaerator are heat exchanged, and the heat in the exhaust steam is recovered and utilized.

[0053] The inlet end of the deaerator 3 is connected to the deaerator water supply pipe 24 and the deaerator water inlet pipe 16, and the outlet end is connected to the deaerator exhaust pipe and the deaerator outlet pipe 25; the desalted water is deoxygenated in the deaerator, and the desalted water after deoxygenation is transported to the boiler for use, and the exhaust steam generated during the deoxygenation process is discharged to the muffler for venting or the exhaust steam recovery device for heat recovery.

[0054] The inlet end of the heating station 4 is connected to the steam inlet pipe 22 of the heating station, and the outlet end is connected to the hot water pipe 23 of the heating station; further, the water inlet pipe 15 of the heating station is connected to the hot water pipe 23 of the heating station.

[0055] The condensate outlet pipe 17 at the inlet end of the soft water tank 5 is connected to the soft water tank water inlet pipe 11 , and the outlet end is connected to the soft water tank water outlet pipe 26 .

[0056] The inlet end of the muffler 6 is connected to the exhaust steam vent pipe 13, and the outlet pipe is connected to the muffler outlet pipe 14. The exhausted exhaust steam is vented after being silenced and noise-reduced by the muffler, thereby reducing noise pollution.

[0057] Furthermore, in order to flexibly adjust the system, a valve I is installed on the exhaust steam vent pipe 13, a valve II is installed on the exhaust steam inlet pipe 12, a valve III is installed on the exhaust steam recovery device water inlet pipe 8, and a valve IV is installed on the soft water tank water inlet pipe.

[0058] From the outlet pipe 19 of the slag cooler used for heat exchange and cooling of slag,

[0059] Through the exhaust steam recovery unit water inlet pipe 8, to the bottom of the exhaust steam recovery unit 2,

[0060] Through the exhaust steam recovery device outlet pipe 21, the deaerator inlet pipe 16, to the deaerator 3,

[0061] Through the exhaust pipe 20 of the deaerator, through the exhaust steam inlet pipe 12, to the top of the exhaust steam recovery device 2;

[0062] This process constitutes an open heat circulation system.

[0063] In the heat circulation system:

[0064] The downstream of the slag cooler outlet pipe 19 is connected to the soft water tank 5 through the soft water tank inlet pipe 11;

[0065] The bottom of the soft water tank 5 is connected to a soft water tank outlet pipe 26. While obtaining soft water, the system can effectively release and utilize upstream heat through the configuration of the exhaust steam recovery device 2.

[0066] The upstream of the heating station 4 is connected with the heating station steam inlet pipe 22, and the downstream is connected with the heating station hot water pipe 23;

[0067] The water inlet pipe 15 of the heating station branched from the outlet pipe 21 of the exhaust steam recovery device is connected downstream to the hot water pipe 23 of the heating station downstream of the heating station 4 for supplementary heat of the heating station.

[0068] The utility model is a heat recovery and utilization unit of a boiler system. The slag formed after the coal is burned in the boiler has a temperature of about 900°C and is transported to the slag cooler 1 through the slag input pipe 9. The desalted water has a pressure of about 0.5MPa and a temperature of about 35°C and enters the slag cooler 1 through the slag cooler water inlet pipe. In the slag cooler 1, the desalted water exchanges heat with the slag. After the slag is cooled to room temperature, it is transported to the outside through the slag output pipe 10 for treatment. The desalted water that absorbs the heat of the slag has a temperature of about 60°C and a pressure of about 0.5MPa. After exiting the slag cooler through the slag cooler water outlet pipe 19, it is divided into two paths: under normal circumstances, it enters the exhaust steam recovery device 2 through the exhaust steam recovery device water inlet pipe 8, and enters the soft water tank 5 through the soft water tank water inlet pipe 11 when the exhaust steam recovery device is abnormal.

[0069] Desalted water with a temperature of about 60°C and a pressure of about 0.5MPa enters the tube side of the exhaust steam recovery device 2 through the exhaust steam recovery device water inlet pipe 8, and the exhaust steam discharged from the deaerator 3 has a pressure of about 0.5MPa and a temperature of about 158°C and enters the shell side of the exhaust steam recovery device 2 through the exhaust steam inlet pipe 12. Exhaust steam and desalted water exchange heat in the exhaust steam recovery device. After absorbing the heat of the exhaust steam, the desalted water is heated from 60°C to about 85°C, and is discharged through the exhaust steam recovery device water outlet pipe 21, and then divided into two paths: one path is connected to the heating station hot water 23 through the heating station water inlet pipe 15, and the other path enters the deaerator through the deaerator water inlet pipe 16 and is used as deaerator feed water. After the exhaust steam absorbs heat, the water vapor entrained in the exhaust steam is condensed, and the condensate with a pressure of about 0.5MPa and a temperature of about 60°C enters the soft water tank 5 through the condensate outlet pipe 17 for recycling. Non-condensable gas is discharged into the atmosphere through the exhaust steam recovery device exhaust pipe 18.

[0070] Desalted water with a temperature of about 85°C and a pressure of about 0.5MPa enters the deaerator 3 through the deaerator water inlet pipe 16 as deaerator feed water. At the same time, the inlet end of the deaerator 3 is also connected to the deaerator water supply pipe 24. When the flow rate of desalted water with a temperature of about 85°C and a pressure of about 0.5MPa from the deaerator water inlet pipe 16 does not meet the use requirements of the deaerator, desalted water at room temperature can be added to the deaerator through the deaerator water supply pipe 24 for use by the deaerator. The deoxygenated desalted water is output through the deaerator water outlet pipe 25 and used as boiler feed water. The exhaust steam generated during the deoxygenation process is discharged through the deaerator exhaust pipe 20 and is divided into two routes: under normal circumstances, it enters the exhaust steam recovery device through the exhaust steam inlet pipe 12 to recover heat; when the exhaust steam recovery device is abnormal, it enters the muffler 6 through the exhaust steam vent pipe 13, and is discharged into the atmosphere through the muffler outlet pipe 14 after silencing and noise reduction.

[0071] The inlet of the heating station 4 is connected to the steam inlet pipe 22 of the heating station, and the outlet is connected to the hot water pipe 23 of the heating station. Traditional central heating stations generally use steam-water heat exchangers to heat circulating water with 0.5MPa saturated steam. The hot water temperature is about 80℃-90℃ and enters the central heating main through the hot water pipe 23 of the heating station.

[0072] The outlet end of the soft water tank 5 is connected to the soft water tank outlet pipe 26. The desalted water and condensate in the soft water tank are sent to the downstream cooling and refining process through the soft water tank outlet pipe 26, and are recycled after further cooling and refining, saving energy.

[0073] During the heating season, the desalted water with a temperature of about 85°C and a pressure of about 0.5 MPa after absorbing the heat of exhaust steam is connected to the hot water pipe 23 of the heating station through the water inlet pipe 15 of the heating station. In this way, the steam consumption of the heating station can be reduced. If the flow rate of this part of the desalted water can meet the heating requirements, the heating station can also be stopped, and part of the hot soft water can replace the heating hot water, effectively reducing the consumption and operation cost of the heating station.

[0074] In the non-heating season, the desalted water with a temperature of about 85°C and a pressure of about 0.5MPa after absorbing the exhaust steam heat enters the deaerator through the deaerator water inlet pipe 16. The deaeration process requires the use of steam to heat the desalted water in the deaerator to a boiling state to remove the oxygen and other non-condensable gases dissolved in the water. Compared with the conventional deaerator using normal temperature desalted water, the use of 85°C desalted water can effectively reduce the amount of steam used in the deaeration process, saving energy and reducing consumption.

[0075] Under normal working conditions, valve I27 and valve IV30 are closed, valve II28 and valve III29 are opened, and the deoxygenated exhaust steam and the desalted water that absorbs the heat of the slag enter the exhaust steam recovery device to recover heat. When the exhaust steam recovery device fails or other abnormal working conditions occur, valve I27 and valve IV30 are opened, valve II28 and valve III29 are closed, and the deoxygenated exhaust steam is discharged after silencing and noise reduction; the desalted water that absorbs the heat of the slag directly enters the soft water tank 5 through the soft water tank inlet pipe 11 for recycling. In this way, the system can be flexibly adjusted to ensure the stable operation of the system.

Claims

1. A heat recovery unit for a boiler system, characterized in that It includes a slag cooler (1), an exhaust steam recovery device (2), a deaerator (3), a heating station (4), a soft water tank (5), and a muffler (6); A slag cooler water inlet pipe (7) and a slag cooler water outlet pipe (19) are provided in the heat exchange process of the slag cooler (1) for heat exchange; The end of the slag cooler water outlet pipe (19) is connected to the soft water tank (5); A water inlet pipe (8) for an exhaust steam recovery device is connected in parallel to the slag cooler water outlet pipe (19), and the end of the water inlet pipe (8) for the exhaust steam recovery device is connected to the bottom of the exhaust steam recovery device (2); The exhaust steam recovery device outlet pipe (21) at the bottom of the exhaust steam recovery device (2) is connected downstream to the hot water pipe (23) of the heating station; A middle part of the exhaust steam recovery device outlet pipe (21) is split into a deaerator water inlet pipe (16) connected to the top of the deaerator (3) tank, and another part is split into a heating station water inlet pipe (15) connected to the heating station (4); The condensate outlet pipe (17) at the lower part of the tower body of the exhaust steam recovery device (2) is connected downstream to the soft water tank (5); The middle part of the tower body of the exhaust steam recovery device (2) is connected to an exhaust steam recovery device exhaust pipe (18), and the exhaust steam recovery device exhaust pipe (18) is vented; The deaerator (3) tank top is provided with a deaerator water supply pipe (24) and a deaerator exhaust pipe (20), and the tank bottom is provided with a deaerator water outlet pipe (25); The exhaust pipe (20) of the deaerator is divided into two paths, one of which is the exhaust steam inlet pipe (12) connected to the top of the exhaust steam recovery device (2); and the other is the exhaust steam vent pipe (13) connected to the muffler (6); The muffler (6) is connected to the muffler air outlet pipe (14).

2. The heat recovery unit of a boiler system according to claim 1, characterized in that: A valve III (29) is provided on the water inlet pipe (8) of the exhaust steam recovery device; A valve IV (30) is provided on the slag cooler water outlet pipe (19) downstream of the parallel flow splitting node of the slag cooler water outlet pipe (19) and the exhaust steam recovery device water inlet pipe (8); Either valve III (29) or valve IV (30) is set to normally open, or both are set to normally open.

3. The heat recovery unit of a boiler system according to claim 1, characterized in that: The pipeline configuration of the exhaust steam inlet pipe (12) and the exhaust steam vent pipe (13) connected in parallel downstream of the exhaust pipe (20) output from the top of the deaerator (3) tank is as follows: A valve I (27) is provided on the exhaust steam inlet pipe (12); A valve II (28) is arranged on the exhaust steam vent pipe (13).

4. The heat recovery unit of a boiler system according to claim 1, characterized in that: From the outlet pipe (19) of the slag cooler used for heat exchange cooling of the slag, Through the exhaust steam recovery device inlet pipe (8), to the bottom of the exhaust steam recovery device (2), Through the exhaust steam recovery device outlet pipe (21), the deaerator inlet pipe (16), to the deaerator (3), Through the exhaust pipe (20) of the deaerator, through the exhaust steam inlet pipe (12), to the top of the exhaust steam recovery device (2); This process constitutes an open heat circulation system.

5. The heat recovery unit of a boiler system according to claim 4, characterized in that: In the heat circulation system: The downstream of the slag cooler water outlet pipe (19) is connected to the soft water tank (5) through the soft water tank inlet pipe (11); The bottom of the soft water tank (5) is connected to a soft water tank outlet pipe (26).

6. The heat recovery unit of a boiler system according to claim 1, characterized in that: The upstream of the heating station (4) is connected to a heating station steam inlet pipe (22), and the downstream is connected to a heating station hot water pipe (23); The water flow branched from the exhaust steam recovery device outlet pipe (21) is connected downstream to the heating station hot water pipe (23) downstream of the heating station (4).

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