CN106439783A - Heat energy efficient utilization system for recovering deaerator exhaust steam and heating fan heater simultaneously - Google Patents

Abstract

The invention provides a heat energy efficient utilization system for recovering the exhaust steam of the deaerator while heating the heater, comprising a boiler (1), a deaerator (9), a hybrid heat exchanger (11), a heater (14 ), the heater (14) is arranged in the air inlet pipe of the boiler (1), and the exhaust gas outlet of the deaerator (9) is connected with the hybrid heat exchanger (11) through the exhaust steam outlet branch pipe (21), and the heater ( 14) Connected with the hybrid heat exchanger (11), the heater (14) can utilize the heat in the exhaust air discharged from the deaerator (9) to heat the air in the air intake duct. The system can not only recycle and utilize the waste heat and waste energy of the deaerator, but also meet the requirements of a new optimized system for increasing the temperature of the cold air at the inlet of the air preheater on the boiler side. Less affected.

Description

High-efficiency heat energy utilization system for recovering exhaust steam from deaerator while heating heater

technical field

The invention relates to the field of waste heat recovery, in particular to a heat energy efficient utilization system for recovering exhaust steam from a deaerator and heating a heater during operation of a power station unit.

Background technique

Energy conservation and emission reduction of thermal power units is an important energy strategy in China. In China, coal-fired power plants consume nearly half of the country's coal production. With the continuous rise of coal energy prices in recent years, the cost of coal-based power generation is also increasing. All thermal power units are facing huge energy-saving pressure and are constantly seeking New technologies for reducing consumption and energy saving to achieve energy saving and emission reduction.

The exhaust of the deaerator in the power plant is to discharge the mixture of saturated steam and air with lower pressure and temperature directly to the air. Based on its low working capacity, it will not be used, resulting in greater heat loss and high-quality clean water. loss. Under the background of energy crisis and water resource shortage, the exhaust gas recovery of deaerator is a practical and effective method. There is a steam exhaust hole on the top of the deaerator, using the power of part of the steam in the deaerator to discharge the separated gas from the feed water out of the shell in time to ensure a stable deaeration effect, but it will bring a certain amount of working fluid and heat loss. The exhaust temperature of the deaerator in the thermal power plant is generally around 150°C to 170°C; this uncontaminated low-temperature steam can be used for waste heat recovery and is directly discharged to the atmosphere without being used, resulting in waste of energy and heat of the environment. pollute. Therefore, how to economically and environmentally friendly use the deaerator exhaust steam to improve energy utilization efficiency has become an important research topic in the current power generation industry.

The prospect of recovery and utilization of deaerator waste steam is broad. Through the unremitting development of waste steam waste heat utilization technology at home and abroad, there are many mature devices on the market. In terms of technical requirements, it is divided into direct utilization technology, air-cooled heat exchanger technology, surface heat exchanger technology, hybrid heat exchanger technology, water spray cooling energy storage technology, volumetric heater technology and vapor (liquid) injection Type heat pump utilization technology. The waste steam recovery device is not only used in the power generation industry, but has been widely used in the utilization and recovery of boiler deaerator waste heat in various industries such as petrochemical, light industry, textile, food, papermaking, steel, heating, etc.

Contents of the invention

In order to fully utilize the exhaust steam of the deaerator, the present invention provides a high-efficiency thermal energy utilization system for recovering the exhaust steam of the deaerator and heating the heater at the same time. It can not only recycle and utilize the waste heat and waste energy of the deaerator, but also meet the needs of the new optimized system for increasing the temperature of the cold air at the inlet of the air preheater on the boiler side. Small. Therefore, the high-efficiency thermal energy utilization system for recovering oxygen-depleted steam while heating the cold air of the boiler side heater is suitable for the technical transformation of the existing power generation industry.

The technical solution adopted by the present invention to solve the technical problem is: a high-efficiency heat utilization system for recovering exhaust gas from the deaerator while heating the heater, including a boiler, a deaerator, a hybrid heat exchanger, and a heater. The oxygen generator is connected to the boiler, the heater is installed in the air inlet pipe of the boiler, the exhaust gas outlet of the deaerator is connected to the first gas inlet of the hybrid heat exchanger through the exhaust steam outlet branch pipe, and the heater is connected through the first connecting pipeline and the second gas inlet. The second connection pipeline is connected with the hybrid heat exchanger, and the heater can use the heat in the exhaust air discharged from the deaerator to heat the air in the air inlet pipe.

The high-efficiency heat utilization system for recovering the exhaust steam of the deaerator while heating the heater also includes a drain tank, and the first liquid outlet of the hybrid heat exchanger is connected to the inlet of the drain tank.

The outlet of the drain tank is connected to the inlet of the deaerator through a water delivery pipeline, and a drainage pump is arranged on the water delivery pipeline.

The drain pump is connected with an electric valve in parallel.

The first liquid inlet of the hybrid heat exchanger is connected with a cooling water supply line, and a valve is arranged on the cooling water supply line.

The water delivery line is connected to the condensate supply line.

The water delivery pipeline is connected with the supply pipeline for industrial and domestic heat users.

The first gas outlet of the hybrid heat exchanger is connected to the inlet of the heater through a first connecting pipeline, and the second liquid inlet of the hybrid heat exchanger is connected to the outlet of the heater through a second connecting pipeline.

Both the first connecting pipeline and the second connecting pipeline are provided with electric valves.

The top of the hybrid heat exchanger is provided with an exhaust port.

The beneficial effects of the present invention are: the high-efficiency heat utilization system for recovering the exhaust steam of the deaerator and heating the heater at the same time enters the exhaust steam of the deaerator at about 150°C to 170°C and domestic water, desalinated water or condensed water respectively into the mixing Type heat exchanger for heat and mass exchange. The heat released by the deaerator is condensed into water and enters the drain tank. After passing through the drain pump, part of it is pumped out and re-enters the condensed water system. Part of it is used for industrial and domestic heat users, and the rest is returned to the deaerator. At the same time, the low-pressure extraction steam in the heater is used to make up for the reduced heat absorption of the air in the air preheater to heat the cold air. The system has the advantages of small footprint, low investment, simple system, convenient operation, high steam quality and stable system operation. It uses the heat energy of the exhausted steam of the low-grade deaerator to replace it for heating industrial domestic water, desalted water or condensed water. The thermal energy is introduced into the heating system on the boiler side to heat the cold air, so as to improve the thermal power conversion efficiency of the unit, better realize the energy counterpart and cascade utilization, and achieve the purpose of improving the utilization rate of power generation energy.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention.

Fig. 1 is a schematic structural diagram of a heat energy efficient utilization system for recovering exhaust steam from a deaerator while heating a heater.

Fig. 2 is a structural schematic diagram of a hybrid heat exchanger.

1. Boiler; 2. High-temperature rotary air preheater; 3. Low-temperature rotary air preheater; 4. Smoke-water heat exchanger; 5. High-pressure cylinder of steam turbine; 6. Medium-pressure cylinder of steam turbine; 7. Low-pressure cylinder of steam turbine ;8. Generator; 9. Deaerator; 10. Condenser; 11. Hybrid heater; 12. Drain tank; 13. Drain pump; 14. Heater; 15. Electric valve;

21. Exhaust steam outlet branch pipe; 22. Water delivery pipeline; 23. Cooling water supply pipeline; 24. Condensed water supply pipeline; 25. Industrial and domestic heat user supply pipeline;

141. The first connecting pipeline; 142. The second connecting pipeline;

111, first gas inlet; 112, first liquid outlet; 113, first liquid inlet; 114, first gas outlet; 115, second liquid inlet; 116, exhaust port; 117, liquid level.

detailed description

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

A high-efficiency heat utilization system for recovering exhaust steam from a deaerator while heating a heater, comprising a boiler 1, a deaerator 9, a hybrid heat exchanger 11, and a heater 14, the deaerator 9 is connected to the boiler 1, and the heater The fan 14 is arranged in the air inlet pipe of the boiler 1, the exhaust gas outlet of the deaerator 9 is connected to the first gas inlet 111 of the hybrid heat exchanger 11 through the exhaust steam outlet branch pipe 21, and the heater 14 is connected to the first connecting pipeline 141 and The second connecting pipeline 142 is connected to the hybrid heat exchanger 11 , and the heater 14 can use the heat in the exhaust air discharged from the deaerator 9 to heat the air in the air inlet pipe, as shown in FIG. 1 .

In this embodiment, the high-efficiency heat utilization system for recovering exhaust steam from the deaerator while heating the heater further includes a drain tank 12 , and the first liquid outlet 112 of the hybrid heat exchanger 11 is connected to the inlet of the drain tank 12 . The outlet of the drain tank 12 is connected to the inlet of the deaerator 9 through a water delivery line 22 on which a drain pump 13 is arranged. The drain pump 13 is connected with an electric valve 15 in parallel.

In this embodiment, the first liquid inlet 113 of the hybrid heat exchanger 11 is connected to the cooling water supply line 23 . The water delivery pipeline 22 is connected with a condensed water supply pipeline 24 for supplying condensed water to the condensed water system. The water delivery pipeline 22 is connected with an industrial domestic heat user supply pipeline 25 for supplying domestic hot water.

In this embodiment, the first gas outlet 114 of the hybrid heat exchanger 11 is connected to the inlet of the heater 14 through the first connecting pipeline 141 , and the second liquid inlet 115 of the hybrid heat exchanger 11 is connected through the second connecting pipeline 142 Connect with the outlet of heater 14. The top of the hybrid heat exchanger 11 is provided with an exhaust port 116 . Both the first connecting pipeline 141 and the second connecting pipeline 142 are provided with electric valves, as shown in FIG. 1 and FIG. 2 .

The following introduces the principle of the high-efficiency heat utilization system for recovering the exhaust steam of the deaerator while heating the heater: the system mainly includes a boiler 1, a high-temperature rotary air preheater 2, a low-temperature rotary air preheater 3, smoke water Heat exchanger 4, steam turbine high pressure cylinder 5, steam turbine medium pressure cylinder 6 and steam turbine low pressure cylinder 7, generator 8, deaerator 9, condenser 10, hybrid heater 11, drain tank 12, drain pump 13 and heater fan14.

The system has a high-temperature rotary air preheater 2, a smoke-water heat exchanger 4, a low-temperature rotary air preheater 3, a steam turbine high-pressure cylinder 5, a steam turbine medium-pressure cylinder 6 and The low-pressure cylinder 7 of the steam turbine is connected in series with the generator 8, and the low-pressure cylinder 7 of the steam turbine sends the condensed water to 8# low-pressure heater H8, 7# low-pressure heater H7, 6# low-pressure heater H6, and 5# low-pressure heater in turn through the condenser 10 The heater H5 is then sent to the deaerator 9, and the condensed water passing through the deaerator 9 is sent to the 3# high pressure heater H3, 2# high pressure heater H2, and 1# high pressure heater H1 in turn, and the exhaust steam of the deaerator passes through The exhaust steam outlet branch pipe 21 is connected to the inlet of the low-temperature section of the hybrid heat exchanger 11, the drain tank 12 and the drain pump 13, and then connected to the drain port of the deaerator. The first gas inlet 111 of the device 11 (the spare port is connected to the low-temperature section), can be directly connected to the deaerator 9 and the exhaust gas into the hybrid heat exchanger 11 to take over when there are few equipment interfaces, and the heater 14 passes through the valve pipe It is connected with the first gas outlet 114 and the second liquid inlet 115 (the inlet and outlet of the high temperature section) of the hybrid heat exchanger 11 . The heater 14 and the hybrid heat exchanger 11 all adopt mature products in the current market.

The above-mentioned high-efficiency heat utilization system for recycling the exhaust steam of the deaerator and heating the heater at the same time, on the exhaust side of the deaerator head, the exhaust steam at about 150°C to 170°C flows through the hybrid heat exchanger in sequence 11 and the drain box 12 return the deaerator 9 through the drain pump 13.

When the cooling water source supplied by the cooling water supply line 23 uses desalted water or condensed water, the non-condensable gas is emptied through the exhaust port 116 of the hybrid heat exchanger 11, and the desalted water or condensed water after absorbing heat enters the drain tank 12, Returning to the deaerator 9 through the drain pump 13 realizes recovery of waste heat and waste energy.

When the cooling water source supplied by the cooling water supply line 23 adopts domestic water, demineralized water and condensed water, the condensed water mixes with the cooling water and enters the drain tank 12, and returns to the deaerator 9 through the drain pump 13, and a part is drawn out to be supplied by the condensed water. The pipeline 24 enters the condensate water system, a part of it is supplied to domestic hot water through the industrial domestic heat user supply pipeline 25, and the rest is returned to the deaerator 9 to realize recovery of working fluid and heat.

The air heater 14 extracts part of the hot steam in the hybrid heat exchanger 11 to preheat the cold air in the air inlet duct before entering the air preheater, increases the temperature of the cold air, and reduces the temperature of the cold air in the air preheater. Heat absorption. The condensed and exothermic steam is filled into the corresponding drain pipes through the drain box 12 and the drain pump 13 .

In the case of sufficient exhaust steam energy, the heater 14 is connected to the hybrid heat exchanger 11 through the corresponding pipeline valve, and a part of the heat in the hybrid heat exchanger 11 is used to heat the condensed water, and the rest is used for the high temperature of the heat exchanger side. The heat energy in the heater system heats the cold air in the heater system, so that the utilization rate of energy consumption is maximized while the exhaust steam of the deaerator is basically unchanged. In the case of insufficient exhaust steam energy, when the temperature of demineralized water or condensed water reaches 70°C, the heating of condensed water is stopped through valve control, and the high-grade steam extracted from the hybrid heat exchanger 11 is drawn into the heater 14 and cooled with cold air according to the site operation conditions. Heat exchange, increase the temperature of the cold air, and maximize the utilization rate of energy consumption. Use the heat energy of the exhausted steam of the low-grade deaerator to replace the heat energy used for heating industrial domestic water, desalted water or condensed water, and introduce it into the heating system on the boiler side to heat the cold air, so as to improve the thermal power conversion efficiency of the unit , to better realize energy counterparts and cascade utilization, and achieve the purpose of improving the utilization rate of power generation energy.

The above is only a specific embodiment of the present invention, and cannot limit the scope of the invention, so the replacement of its equivalent components, or the equivalent changes and modifications made according to the patent protection scope of the present invention, should still fall within the scope of this patent. category. In addition, the technical features and technical features, technical features and technical solutions, and technical solutions and technical solutions in the present invention can be used in free combination.

Claims (10)

1. a kind of heat the heat energy effective utilization system of warm-air drier it is characterised in that this use for reclaiming oxygen-eliminating device exhaust steam simultaneously Include boiler (1), oxygen-eliminating device (9), hybrid in the heat energy effective utilization system reclaiming oxygen-eliminating device exhaust steam and heating warm-air drier simultaneously Heat exchanger (11), warm-air drier (14), oxygen-eliminating device (9) is connected with boiler (1), and warm-air drier (14) is arranged at the blast pipe of boiler (1) Road, the first gas entrance of arm (21) and direct contact heat exchanger (11) is drawn in the weary gas outlet of oxygen-eliminating device (9) by exhaust steam (111) connect, warm-air drier (14) passes through the first connecting pipeline (141) and the second connecting pipeline (142) and direct contact heat exchanger (11) connect, the air in this intake stack of heat in the weary gas that warm-air drier (14) can be discharged using oxygen-eliminating device (9).

2. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 1, It is characterized in that, this is used for reclaiming oxygen-eliminating device exhaust steam and heats the heat energy effective utilization system of warm-air drier simultaneously and also includes drain tank (12), first liquid outlet (112) of direct contact heat exchanger (11) is connected with the entrance of drain tank (12).

3. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 2, It is characterized in that, the outlet of drain tank (12) is connected with the entrance of oxygen-eliminating device (9) by waterline (22), waterline (22) It is provided with drainage pump (13).

4. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 3, It is characterized in that, drainage pump (13) is parallel with electrodynamic valve (15).

5. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 1, It is characterized in that, the first liquid entrance (113) of direct contact heat exchanger (11) is connected with chilled(cooling) water supply (CWS) pipeline (23), cooling water Supply line (23) is provided with valve.

6. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 3, It is characterized in that, waterline (22) is connected with condensate supply line (24).

7. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 3, It is characterized in that, waterline (22) is connected with industrial life heat user supply line (25).

8. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 1, It is characterized in that, first gas outlet (114) of direct contact heat exchanger (11) pass through the first connecting pipeline (141) and warm-air drier (14) entrance connects, and the second liquid entrance (115) of direct contact heat exchanger (11) passes through the second connecting pipeline (142) and warm braw The outlet of machine (14) connects.

9. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 8, It is characterized in that, the first connecting pipeline (141) and the second connecting pipeline (142) are equipped with electrodynamic valve.

10. the heat energy effective utilization system simultaneously heating warm-air drier for reclaiming oxygen-eliminating device exhaust steam according to claim 1, It is characterized in that, the top of direct contact heat exchanger (11) is provided with air vent (116).