Steam exhaust waste heat indirect recovery heat supply system of steam extraction and condensation steam turbine generator unit

Abstract

The invention belongs to the technical field of coke dry quenching in the coking industry, and particularly relates to a steam exhaust waste heat indirect recovery heat supply system of a steam extraction and condensation steam turbine generator unit, which is characterized by comprising an absorption heat pump unit, a peak heat exchanger, a heat exchange station and a heat supply network circulating water pump, a medium outlet of the condenser is connected with the evaporator or the cooling tower, heat supply network return water of the heat exchange station is communicated with the absorber through a heat supply network return water pipeline, and the condenser is connected with the peak heat exchanger. An inlet of the generator is connected with a steam extraction pipeline of the steam extraction and condensation steam turbine generator unit, and an outlet of the generator is connected with a condensate water outlet of the peak heat exchanger. The heat supply network circulating water pump is arranged on the heat supply network water return pipeline. The absorption heat pump unit has the beneficial effects that the absorption heat pump is applied to supply heat, only a small amount of extracted steam is used as a driving heat source to recover low-temperature latent heat carried in dead steam in the operation process of the absorption heat pump unit, the vacuum of the steam turbine is kept not damaged, and the steam turbine operates safely.

Description

Technical Field

[0001] The present invention belongs to the technical field of coke dry quenching in the coking industry, and particularly relates to an indirect heat recovery heating system for the waste heat of the exhaust steam of a steam extraction condensing steam turbine generator set. Background Art

[0002] The coke dry quenching waste heat power generation system is an important part of the entire coke dry quenching process system. The coke dry quenching boiler absorbs the heat of the circulating gas to generate steam, and the steam drives a steam turbine generator set to generate electricity and heat to realize the recovery of the sensible heat of the red coke. The coke dry quenching waste heat power generation system is the main measure for circular economy and energy conservation in the coke dry quenching device.

[0003] At present, combined heat and power (CHP) central heating is the main heating method in northern towns of China. With the acceleration of the urbanization process, there is a shortage of central heating heat sources in cities, and it is necessary to increase heating heat sources. The coke dry quenching waste heat power generation project in the intercity coking plant can provide heating heat sources for surrounding towns. There are two traditional coke dry quenching waste heat power generation and heating methods: one is to use the low-pressure extraction steam of the steam turbine as the heating steam source, which enters the steam-water heat exchanger to heat the return water of the secondary network. The low-temperature exhaust steam of the steam turbine enters the condenser for cooling, and the circulating cooling water takes away a large amount of latent heat of vaporization in the exhaust steam and dissipates it in the cooling tower. This treatment method causes a large amount of energy waste. The other is low-vacuum heating. Under the condition of keeping the exhaust pressure of the unit not exceeding the design value, the vacuum degree of the unit is destroyed, the exhaust steam temperature of the steam turbine is increased, and the circulating cooling water at about 40 °C is directly supplied to the heat user for heating. Low-vacuum heating can recover the low-grade heat energy carried by the exhaust steam of the steam turbine, but due to the decrease in the vacuum degree, the power generation is reduced, and the heating temperature is limited by the exhaust pressure of the unit, and it cannot meet the water temperature requirements of the heating primary network, so its application is limited.

[0004] An absorption heat pump is a cyclic system that uses a low-grade heat source to pump heat from a low-temperature heat source to a high-temperature heat source. It is an effective device for recovering and utilizing low-temperature heat energy, and has the dual functions of saving energy and protecting the environment. Absorption heat pumps can be divided into two categories. The first type of absorption heat pump, also known as a heat-boosting heat pump, uses a small amount of high-temperature heat source (such as steam, high-temperature hot water, combustion heat of combustible gas, etc.) as the driving heat source to generate a large amount of medium-temperature useful heat energy. That is, driven by high-temperature heat energy, the heat energy of the low-temperature heat source is raised to medium temperature, thereby improving the utilization efficiency of heat energy. The performance coefficient of the first type of absorption heat pump is greater than 1, generally 1.5 - 2.5. The second type of absorption heat pump, also known as a temperature-rising heat pump, uses a large amount of medium-temperature heat source to generate a small amount of high-temperature useful heat energy. That is, driven by medium-low temperature heat energy, using the heat potential difference between a large amount of medium-temperature heat source and low-temperature heat source, the heat generated is less than but at a higher temperature than the medium-temperature heat source, and part of the medium-low heat energy is transferred to a higher temperature level, thereby improving the utilization grade of the heat source. Summary of the Invention

[0005] The object of the present invention is to provide an indirect heat recovery heating system for the exhaust steam waste heat of a steam extraction condensing steam turbine generator set, to overcome the deficiencies of the prior art, and to solve the problems of waste of latent heat of exhaust steam and limited heating temperature. By using a small amount of extracted steam as the driving heat source during the operation of the absorption heat pump unit to recover the low-temperature latent heat carried by the exhaust steam, the vacuum of the steam turbine is not damaged, ensuring the safe operation of the steam turbine; combined with a peak heat exchanger, the hot water supply temperature reaches the standard of the first-level heating network, and the hot water temperature can be adjusted according to the heating load.

[0006] To achieve the above object, the present invention is realized through the following technical solutions:

[0007] An indirect heat recovery heating system for the exhaust steam waste heat of a steam extraction condensing steam turbine generator set, characterized by comprising an absorption heat pump unit, a peak heat exchanger, a heat exchange station, and a heat network circulating water pump. The absorption heat pump unit is a single-effect lithium bromide absorption heat pump unit, including a generator, a condenser, an evaporator, an absorber, and a heat exchanger. The inlet of the evaporator is connected to the return water pipe of the circulating cooling water of the condenser in the steam extraction condensing steam turbine generator set through a branch pipe in front of the cooling tower. The outlet of the evaporator is connected to the inlet of the circulating cooling water of the condenser. The outlet of the circulating cooling water of the condenser is connected to the evaporator or the cooling tower. The return water of the heat network of the heat exchange station is connected to the inlet of the cooling water of the absorber through a heat network return water pipe. The outlet of the cooling water of the condenser is connected to the inlet of the medium of the peak heat exchanger. The outlet of the medium of the peak heat exchanger is connected to the water inlet of the heat exchange station. The inlet of the generator is connected to the extraction steam pipe of the steam extraction condensing steam turbine generator set, and the outlet of the generator is connected to the condensate outlet of the peak heat exchanger. The extraction steam pipe is also connected to the heat source inlet of the peak heat exchanger. A heat network circulating water pump is provided on the heat network return water pipe.

[0008] The steam extraction condensing steam turbine generator set is also connected to a coke dry quenching boiler, a demineralized water tank, a heat pipe heat exchanger, and a deaerator. The main steam pipe of the coke dry quenching boiler is connected to the steam extraction condensing steam turbine generator set. The drain pipe of the coke dry quenching boiler is connected to the deaerator through the main feed water pipe. The inlet side of the deaerator is connected to the outlet of the heat pipe heat exchanger. The inlet of the heat pipe heat exchanger is connected to the demineralized water tank.

[0009] The single-effect lithium bromide absorption heat pump unit is a first-class absorption heat pump, and both the generator and the condenser are in the high-pressure area, while both the absorber and the evaporator are in the low-pressure area.

[0010] The peak heat exchanger is a plate-type steam-water heat exchanger.

[0011] The condensate outlet is connected to the demineralized water tank.

[0012] The steam extraction condensing steam turbine generator set has two operating conditions: steam extraction condensing operation and pure condensing operation. It operates in steam extraction condensing mode during the heating season and can choose steam extraction condensing or pure condensing operation in the non-heating season.

[0013] The return water of the heat network in the heat exchange station enters the absorption heat pump unit, is heated to 79 °C, and then sent to the peak heat exchanger to exchange heat with the extraction steam of the steam turbine, the temperature rises to 90 - 120 °C, and then it is sent back to the heat exchange station to supply heat to users.

[0014] The water output from the demineralized water tank is sent to the heat pipe heat exchanger for heat exchange. After the temperature rises to about 60 - 70 °C, it enters the deaerator for deaeration treatment and then serves as the feed water for the coke dry quenching boiler. The water output from the deaerator is pressurized by the boiler feed water pump and sent to the coke dry quenching boiler to generate high-temperature and high-pressure or medium-temperature and medium-pressure superheated steam, which is supplied to the extraction condensing steam turbine generator set.

[0015] The exhaust steam in the condenser exchanges heat with the circulating cooling water, is condensed into water and then sent back to the demineralized water tank by the condensate pump. The circulating cooling water absorbs heat and the temperature rises to 38 - 40 °C, and then returns to the absorption heat pump unit or the cooling tower for cooling.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1) Applying the absorption heat pump for heating, during the operation of the absorption heat pump unit, only a small amount of extraction steam is used as the driving heat source to recover the low-temperature latent heat carried in the exhaust steam, the vacuum of the steam turbine can be maintained without being damaged, ensuring the safe operation of the steam turbine. By recovering the low-temperature heat of the circulating cooling water in the condenser, indirectly recovering the latent heat of vaporization of the exhaust steam of the extraction condensing steam turbine generator set, improving the quality of the low-temperature waste heat for heating, avoiding the waste of energy caused by the discharge of the exhaust steam waste heat of the steam turbine into the atmosphere and forming heat pollution to the environment, greatly increasing the energy utilization rate of the coke dry quenching system, and playing an important role in energy conservation and emission reduction;

[0018] 2) The absorption heat pump combined with the peak heat exchanger can produce hot water at 90 - 120 °C, meeting the standards of the urban heating primary network, with a longer transmission distance and a wider range of radiated heat users, solving the problem of insufficient urban heating around the coking plant, expanding the heating capacity of the coking plant, and having significant economic benefits and good social benefits;

[0019] 3) The circulating cooling water releases heat and cools down in the absorption heat pump unit and then returns to the condenser to absorb the latent heat of vaporization of the exhaust steam of the steam turbine. It belongs to a closed system without evaporation consumption, and a large amount of circulating cooling water and the power consumption of the cooling tower fan can be saved during the heating season;

[0020] 4) The extraction condensing steam turbine unit operates in the extraction-condensing mode during the heating season, and in the non-heating season, it can operate in the extraction-condensing or pure condensing mode according to whether hot water or extraction steam for production is needed. The operating conditions can be adjusted according to the requirements of the coking plant, with strong process flexibility;

[0021] 5) The system is applicable to various types of coke dry quenching extraction condensing water-cooled generator sets, with wide applicability. Description of the Drawings

[0022] Figure 1 It is a schematic process flow diagram of an embodiment of the present invention;

[0023] Figure 2 It is a schematic block diagram of the structure of an absorption heat pump unit in an embodiment of the present invention;

[0024] In the figure: 1 - coke dry quenching boiler, 2 - demineralized water tank, 3 - deaerating feed water pump, 4 - heat pipe heat exchanger, 5 - deaerator, 6 - boiler feed water pump, 7 - extraction condensing steam turbine generator set, 8 - condenser, 9 - circulating cooling water pump, 10 - condensate pump, 11 - cooling tower, 12 - absorption heat pump unit, 13 - peak heat exchanger, 14 - heat exchange station, 15 - heat network circulating water pump, 16 - demineralized water pipeline, 17 - deaerating feed water pipeline, 18 - deaerating return water pipeline, 19 - deaerated water pipeline, 20 - main feed water pipeline, 21 - main steam pipeline, 22 - exhaust steam pipeline, 23 - condensate pipeline, 24 - circulating cooling water feed pipeline, 25 - circulating cooling water return pipeline, 26 - extraction pipeline, 27 - condensate water pipeline, 28 - heat network return water pipeline, 29 - intermediate hot water pipeline, 30 - heat network supply pipeline, 31 - 34 - switching valves. Detailed implementation manners

[0025] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with specific embodiments. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments.

[0026] In order to more clearly illustrate the specific implementation manners of the present invention or the technical solutions in the prior art, the specific embodiments required for use in the description of the specific implementation manners or the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some implementation manners of the present invention. For those of ordinary skill in the art, without creative efforts, other specific embodiments can also be obtained based on these specific embodiments.

[0027] Generally, the components of the embodiments of the present invention described and shown in the specific embodiments here can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the specific embodiments is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention.

[0028] Such as Figure 1-2As shown in the figure, it is a schematic process flow diagram of an indirect recovery heating system for the waste steam waste heat of a dry coke quenching power generation water cooling unit according to an embodiment of the present invention, including an absorption heat pump unit 12, a peak heat exchanger 13, a heat exchange station 14, and a heat network circulating water pump 15. The absorption heat pump unit 12 is a single-effect lithium bromide absorption heat pump unit, including a generator, a condenser, an evaporator, an absorber, and a heat exchanger. The inlet of the evaporator is connected to the circulating cooling water return pipe 25 of the condenser 8 in the extraction condensing steam turbine generator set 7 through a front branch pipe of the cooling tower. The outlet of the evaporator is connected to the circulating cooling water inlet of the condenser 8. The circulating cooling water outlet of the condenser 8 is connected to the evaporator or the cooling tower 11 through a circulating cooling water supply pipe 24. The switching is completed by switching valves 31-34. A circulating cooling water pump 9 is provided on the circulating cooling water supply pipe 24. The waste steam in the extraction condensing steam turbine generator set 7 is sent to the steam inlet of the condenser 8 through a waste steam pipe 22. The heat network return water of the heat exchange station 14 is connected to the cooling water inlet of the absorber through a heat network return pipe 28. The cooling water outlet of the condenser is connected to the medium inlet of the peak heat exchanger 13. The medium outlet of the peak heat exchanger 13 is connected to the water inlet of the heat exchange station 14. The inlet of the generator is connected to the extraction pipe 26 of the extraction condensing steam turbine generator set 7. The outlet of the generator is connected to the condensate outlet of the peak heat exchanger 13. The extraction pipe 26 is also connected to the heat source inlet of the peak heat exchanger 13. The heat network circulating water pump 15 is provided on the heat network return pipe 28.

[0029] The waste steam in the condenser 8 exchanges heat with the circulating cooling water, is condensed into water, and then is sent back to the demineralized water tank 2 by a condensate pump 10 through a condensate pipe 23. The circulating cooling water absorbs heat and the temperature rises to 38-40°C, and then returns to the absorption heat pump unit 12 or the cooling tower 11 for cooling.

[0030] The circulating cooling water return pipe 25 from the condenser 8 is sent to the evaporator of the absorption heat pump unit 12 through a front branch pipe of the cooling tower 11. After the heat is absorbed by the heat pump working medium, the circulating cooling water supply pipe 24 returns to the condenser 8 to absorb the latent heat of vaporization of the steam turbine waste steam pipe 22. At the heating end of the absorption heat pump unit 12, the heat network return water 28 from the heat exchange station 14 is pressurized by the heat network circulating water pump 15 and enters the heat pump unit 12. After being heated to intermediate hot water 29 (about 79°C), it is sent to the peak heat exchanger 13 to exchange heat with the steam turbine extraction pipe 26, and the temperature rises to 90-120°C to meet the temperature requirements of the heating primary network, and then is sent back to the heat exchange station 14 to supply heat to users, completing the hot water cycle. The steam turbine extraction steam 26 is sent to the generator of the absorption heat pump unit 12 as a driving heat source. After condensing and releasing heat, it becomes condensate, and is sent back to the deaerator 5 or the demineralized water tank 2 together with the condensate of the peak heat exchanger through a condensate pipe 27.

[0031] The extraction condensing steam turbine generator set 7 is also connected to the coke dry quenching boiler 1, demineralized water tank 2, heat pipe heat exchanger 4, and deaerator 5. The main steam pipe 21 of the coke dry quenching boiler 1 is connected to the extraction condensing steam turbine generator set 7. The drain pipe of the coke dry quenching boiler 1 is connected to the deaerator 5 via the main feed water pipe 20. The inlet side of the deaerator 5 is connected to the outlet of the heat pipe heat exchanger 4, and the inlet of the heat pipe heat exchanger 4 is connected to the demineralized water tank 2.

[0032] The single-effect lithium bromide absorption heat pump unit 12 is the first type of absorption heat pump, where the generator and condenser are both in the high-pressure area, and the absorber and evaporator are both in the low-pressure area.

[0033] The peak heat exchanger 13 is a plate-type steam-water heat exchanger, which can adjust the hot water heating temperature according to the change of heating load. When the temperature rises and the heating load decreases, the steam inlet flow of the peak heat exchanger 13 is reduced to lower the hot water heating temperature; when the temperature drops and the heating load increases, the steam inlet flow of the peak heat exchanger 13 is increased to raise the hot water heating temperature; the heating design should meet the requirements of the maximum heating load.

[0034] The extraction condensing steam turbine generator set 7 has two operating conditions: extraction condensing condition and pure condensing condition. It operates in extraction condensing mode during the heating season and can choose extraction condensing or pure condensing operation in the non-heating season. The coke dry quenching boiler 1 generates high-temperature and high-pressure or medium-temperature and medium-pressure superheated steam to supply the extraction condensing steam turbine generator set 7. In the non-heating season, the extraction condensing steam turbine generator set 7 operates in pure condensing mode. The superheated steam generated by the coke dry quenching boiler 1 expands and does work in the extraction condensing steam turbine generator set 7 and becomes exhaust steam, which is discharged into the condenser 8 from the exhaust port. The switching valves 33 and 34 are opened, and the switching valves 31 and 32 are closed. The circulating cooling feed water (≤32°C) in the sump of the cooling tower 11 is pressurized by the circulating cooling water pump 9 and sent to the condenser 8 to exchange heat with the exhaust steam. The return water of the circulating cooling water absorbs heat and the temperature rises to 38 - 40°C and returns to the cooling tower 11 for cooling. The exhaust steam is condensed into condensate and sent back to the demineralized water tank 2 by the condensate pump 10; during the heating season, the extraction condensing steam turbine generator set 7 operates in extraction condensing mode. A part of the steam is extracted from the extraction port and sent to the absorption heat pump unit 12 and the peak heat exchanger 13, and the other part of the steam completely does work and becomes exhaust steam, which is discharged into the condenser 8 from the exhaust port. The switching valves 31 and 32 are opened, and the switching valves 33 and 34 are closed. The exhaust steam exchanges heat with the circulating cooling water feed water (≤32°C) in the condenser 8, is condensed into condensate and sent back to the demineralized water tank 2 by the condensate pump 10. The return water of the circulating cooling water absorbs heat and the temperature rises to 38 - 40°C and returns to the absorption heat pump unit 12 for heat release and cooling.

[0035] The return water of the heat network in the heat exchange station 14 enters the heat pump through the heat network return water pipe 28, is heated to 79°C, and then sent to the peak heat exchanger 13 through the intermediate hot water pipe 29 to exchange heat with the steam extracted from the steam turbine, and the temperature rises to 90 - 120°C, and then is sent back to the heat exchange station 14 through the heat network supply pipe 30 to supply heat to users.

[0036] The water outlet of the demineralized water tank 2 is sent to the heat pipe heat exchanger 4 for heat exchange through the demineralized water pipeline 16 and the deaerating feed water pipeline 17. An deaerating feed water pump 3 is provided on the demineralized water pipeline 16. After the water outlet temperature of the heat pipe heat exchanger 4 rises to about 60 - 70 °C, it enters the deaerator 5 through the deaerated return water pipeline 18 for deaeration treatment and then serves as the feed water for the coke dry quenching boiler 1. The water outlet of the deaerator 5 is pressurized by the boiler feed water pump 6 on the deaerated water pipeline 19 and sent to the coke dry quenching boiler 1 to generate high-temperature and high-pressure or medium-temperature and medium-pressure superheated steam, which is supplied to the extraction condensing steam turbine generator set 7.

[0037] In the embodiment of the present invention, the extraction steam of the coke dry quenching power generation water-cooled unit is used as the driving heat source. The absorption heat pump unit indirectly recovers the waste steam waste heat by recovering the heat of the circulating cooling water to produce heating hot water; the peak heat exchanger uses the adjustable extraction steam of the coke dry quenching power generation water-cooled unit to secondary heat the heating hot water produced by the absorption heat pump unit. The high-temperature hot water after secondary heating can meet the requirements of the first-level heat supply network. The peak heat exchanger can also adjust the hot water temperature according to the change of the heat supply load. This system can effectively recover the waste steam waste heat of the coke dry quenching power generation water-cooled unit, generate high-temperature heat network water to centrally heat the towns around the coking plant, and improve the heat supply capacity and energy utilization efficiency of the coke dry quenching waste heat system.

[0038] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An indirect waste heat recovery heating system for the exhaust steam of a back-pressure condensing steam turbine generator set, characterized in that, It includes an absorption heat pump unit, a peak heat exchanger, a heat exchange station and a heat network circulating water pump. The absorption heat pump unit is a single-effect lithium bromide absorption heat pump unit, which includes a generator, a condenser, an evaporator, an absorber and a heat exchanger. The inlet of the evaporator is connected to the circulating cooling water return pipe of the condenser in the extraction condensing steam turbine generator set through the front branch pipe of the cooling tower. The outlet of the evaporator is connected to the inlet of the circulating cooling water of the condenser. The outlet of the circulating cooling water of the condenser is connected to the evaporator or the cooling tower. The heat network return water of the heat exchange station is connected to the cooling water inlet of the absorber through the heat network return water pipe. The cooling water outlet of the condenser is connected to the medium inlet of the peak heat exchanger. The medium outlet of the peak heat exchanger is connected to the water inlet of the heat exchange station. The inlet of the generator is connected to the extraction steam pipe of the extraction condensing steam turbine generator set. The outlet of the generator is connected to the condensate outlet of the peak heat exchanger. The extraction steam pipe is also connected to the heat source inlet of the peak heat exchanger. A heat network circulating water pump is provided on the heat network return water pipe.

2. The indirect heat recovery heating system for the exhaust steam waste heat of a steam extraction condensing steam turbine generator set according to claim 1, characterized in that The extraction condensing steam turbine generator set is also connected to a coke dry quenching boiler, a demineralized water tank, a heat pipe heat exchanger and a deaerator. The main steam pipe of the coke dry quenching boiler is connected to the extraction condensing steam turbine generator set. The drain pipe of the coke dry quenching boiler is connected to the deaerator through the main feed water pipe. The water inlet side of the deaerator is connected to the outlet of the heat pipe heat exchanger. The inlet of the heat pipe heat exchanger is connected to the demineralized water tank.

3. An indirect waste heat recovery heating system for the exhaust steam of a back-pressure condensing steam turbine generator set according to claim 1, characterized in that, The single-effect lithium bromide absorption heat pump unit is a first-class absorption heat pump. The generator and the condenser are both in the high-pressure area, and the absorber and the evaporator are both in the low-pressure area.

4. The indirect heat recovery heating system for the exhaust steam waste heat of a steam extraction condensing steam turbine generator set according to claim 1, characterized in that The peak heat exchanger is a plate-type steam-water heat exchanger.

5. The indirect heat recovery heating system for the exhaust steam waste heat of an extraction condensing steam turbine generator set according to claim 1, characterized in that, The condensate outlet is connected to the demineralized water tank.

6. The indirect heat recovery heating system for the exhaust steam waste heat of a back-pressure condensing steam turbine generator set according to claim 1, wherein, The extraction condensing steam turbine generator set has two operating conditions: extraction condensing condition and pure condensing condition. It operates in extraction condensing mode during the heating season and can operate in extraction condensing or pure condensing mode during the non-heating season.

7. An indirect waste heat recovery heating system for the exhaust steam of an extraction condensing steam turbine generator set according to claim 1, characterized in that, The heat network return water of the heat exchange station enters the absorption heat pump unit, is heated to 79 °C and then sent to the peak heat exchanger to exchange heat with the extraction steam of the steam turbine, and is heated to 90 - 120 °C, and then sent back to the heat exchange station to supply heat to users.

8. The indirect heat recovery heating system for the exhaust steam waste heat of a backpressure condensing steam turbine generator set according to claim 2, characterized in that The water from the demineralized water tank is sent to the heat pipe heat exchanger for heat exchange. After the temperature rises to about 60 - 70 °C, it enters the deaerator for deaeration treatment and then serves as the feed water for the coke dry quenching boiler. The water outlet of the deaerator is pressurized by a boiler feed water pump and sent to the coke dry quenching boiler to generate high-temperature and high-pressure or medium-temperature and medium-pressure superheated steam, which is supplied to the extraction condensing steam turbine generator set.

9. The indirect heat recovery heating system for the exhaust steam waste heat of a back-pressure condensing steam turbine generator set according to claim 1, wherein The exhaust steam in the condenser exchanges heat with the circulating cooling water, is condensed into water and then sent back to the demineralized water tank by a condensate pump. The circulating cooling water absorbs heat and the temperature rises to 38 - 40 °C, and then returns to the absorption heat pump unit or the cooling tower for cooling.

Images