CN114909193A - Thermal power generating unit flexible operation system based on molten salt heat storage - Google Patents

Abstract

The present disclosure proposes a flexible operation system for thermal power units based on molten salt heat storage, including: a boiler device, a low temperature tank, a high temperature tank, a first heat exchanger and a second heat exchanger; The liquid end is connected to the liquid outlet end of the low temperature tank, the liquid end of the heat absorption passage of the first heat exchanger is connected to the liquid inlet end of the high temperature tank, and the steam inlet end of the heat release passage of the first heat exchanger is separated from the steam and water of the boiler device The steam outlet end of the first heat exchanger is connected with the liquid outlet end of the heat release passage of the first heat exchanger and the liquid inlet end of the water cooling wall of the boiler device is connected. In the flexible operation system of thermal power unit based on molten salt heat storage disclosed in the present disclosure, the flexible operation of thermal power unit is realized, and the peak shaving capability of the thermal power unit is effectively improved.

Description

A flexible operation system for thermal power units based on molten salt heat storage

technical field

The present disclosure relates to the technical field of thermal power units, in particular to a flexible operation system for thermal power units based on molten salt heat storage.

Background technique

In recent years, the scale and proportion of renewable energy power generation such as wind power and photovoltaics have increased significantly. However, renewable energy has the characteristics of volatility and intermittency. After connecting to the power grid, conventional thermal power units need to increase the capacity of auxiliary services such as peak shaving and peaking. Under the dual background of coal-fired power generating units occupying the main power source position and large-scale unstable renewable energy urgently needing to be connected to the grid, the load regulation capacity of thermal power generating units in my country needs to be improved urgently.

At present, the way to achieve deep peak regulation of thermal power units by reducing the minimum output of the boiler unit is mostly limited by the minimum steady combustion load of the boiler unit. When the steady combustion load of the boiler unit is too low, the burners, coal mills, fans and other equipment Unable to operate stably under too low load, resulting in thermal power unit unable to operate under too low load for a long time; at the same time, the way to achieve deep peak regulation of thermal power unit by reducing the minimum output of boiler unit is also limited by the minimum inlet flue temperature of the denitrification device , When the steady combustion load of the boiler device is too low, the temperature of the exhaust end of the boiler device is also low, which leads to the reduction of the catalyst activity in the denitration device, resulting in a sharp drop in the denitration efficiency of the denitration device, which cannot meet the smoke exhaust requirements of thermal power units. Therefore, the present disclosure proposes a flexible operation system for thermal power units based on molten salt heat storage, so as to improve the peak shaving capability of thermal power units.

SUMMARY OF THE INVENTION

The present disclosure aims to solve one of the technical problems in the related art at least to a certain extent.

Therefore, the purpose of the present disclosure is to provide a flexible operation system for thermal power units based on molten salt heat storage.

In order to achieve the above object, the present disclosure provides a flexible operation system for thermal power units based on molten salt heat storage, including: a boiler device, a low temperature tank, a high temperature tank, a first heat exchanger and a second heat exchanger; the first heat exchanger The liquid inlet end of the heat absorption passage of the heat exchanger is connected with the liquid outlet end of the low temperature tank, the liquid outlet end of the heat absorption passage of the first heat exchanger is connected with the liquid inlet end of the high temperature tank, and the first heat exchanger is connected with the liquid inlet end of the high temperature tank. The steam inlet end of the heat release passage of the heat exchanger is connected with the steam outlet end of the steam-water separator of the boiler device, and the liquid outlet end of the heat release passage of the first heat exchanger is connected with the liquid inlet end of the water cooling wall of the boiler device; The liquid inlet end of the heat release passage of the second heat exchanger is connected to the liquid outlet end of the high temperature tank, and the liquid outlet end of the heat release passage of the second heat exchanger is connected to the liquid inlet end of the low temperature tank, The liquid inlet end of the heat absorption passage of the second heat exchanger is connected to the liquid outlet end of the feed water pump of the boiler device, and the liquid outlet end of the heat absorption passage of the second heat exchanger is connected to the economizer of the boiler device connected to the liquid inlet.

Optionally, the boiler device includes: a furnace body; a water-cooling wall, the water-cooling wall is arranged on the inner wall of the furnace body; the steam-water separator, the liquid outlet end of the steam-water separator is connected to the water-cooling wall The liquid inlet end of the steam-water separator is connected to the liquid outlet end of the water cooling wall; the economizer is arranged in the smoke outlet end of the furnace body, so The liquid outlet end of the economizer is connected with the liquid inlet end of the water cooling wall; the high pressure heater, the liquid outlet end of the high pressure heater is connected with the liquid inlet end of the economizer, and the high pressure heater is connected with the liquid inlet end of the economizer. The steam inlet end is respectively connected with the steam outlet end of the high pressure cylinder of the steam turbine and the steam outlet end of the medium pressure cylinder of the steam turbine; the feed water pump, the liquid outlet end of the feed water pump is connected with the liquid inlet end of the high pressure heater; A superheater group, the superheater group is arranged in the furnace body, the steam inlet end of the superheater group is connected with the steam outlet end of the steam-water separator, and the steam outlet end of the superheater group is connected with the high pressure The inlet end of the cylinder is connected.

Optionally, the flexible operation system of the thermal power unit further includes: a recirculation pump, the recirculation pump is arranged between the liquid outlet end of the heat absorption passage of the first heat exchanger and the liquid inlet end of the water cooling wall. The liquid inlet end of the recirculation pump is connected with the liquid outlet end of the heat absorption passage of the first heat exchanger, and the liquid outlet end of the recirculation pump is connected with the liquid inlet end of the water cooling wall.

Optionally, the superheater group includes: a horizontal low temperature superheater, the steam inlet end of the horizontal low temperature superheater is connected to the steam outlet end of the steam-water separator; a vertical low temperature superheater, the vertical low temperature superheater is The steam inlet end is connected with the steam outlet end of the horizontal low temperature superheater; the partition screen superheater, the steam inlet end of the partition screen superheater is connected with the steam outlet end of the vertical low temperature superheater; the high temperature superheater, the The steam inlet end of the high temperature superheater is connected with the steam outlet end of the partition screen superheater; the final stage superheater, the steam inlet end of the final stage superheater is connected with the steam outlet end of the high temperature superheater, the The steam outlet end of the final stage superheater is connected with the steam inlet end of the high pressure cylinder of the steam turbine; wherein, the partition screen superheater, the high temperature superheater, the final stage superheater, the vertical low temperature superheater, the horizontal The low temperature superheater and the economizer are sequentially distributed along the direction from the furnace hearth of the furnace body to the smoke outlet end of the furnace body.

Optionally, the flexible operation system of the thermal power unit further includes: a first valve body, the first valve body is arranged at the steam outlet end of the steam-water separator and the steam inlet of the heat release passage of the first heat exchanger. The second valve body, the second valve body is arranged on the pipeline between the steam outlet end of the steam-water separator and the steam inlet end of the horizontal low temperature superheater; the third A valve body, the third valve body is arranged on the pipeline between the liquid outlet end of the feed pump and the liquid inlet end of the high-pressure heater; the fourth valve body, the fourth valve body is arranged at the on the pipeline between the liquid outlet end of the feed water pump and the liquid inlet end of the heat absorption passage of the second heat exchanger.

Optionally, the boiler device further includes: a high temperature reheater, the high temperature reheater is arranged in the furnace body, and the high temperature reheater is located in the final stage superheater and the vertical low temperature superheater between, the steam inlet end of the high temperature reheater is connected with the steam outlet end of the high pressure cylinder; the last stage reheater is arranged in the furnace body, and the last stage reheater is The heater is located between the last stage superheater and the high temperature reheater, the steam inlet end of the last stage reheater is connected with the steam outlet end of the high temperature reheater, and the last stage reheater The steam outlet end is connected with the steam inlet end of the medium pressure cylinder.

Optionally, the flexible operation system of the thermal power unit further includes: a third heat exchanger; the heat absorption passage of the third heat exchanger is arranged between the liquid outlet end of the heat absorption passage of the first heat exchanger and the Between the liquid inlet ends of the high temperature tank, the liquid inlet end of the heat absorption passage of the third heat exchanger is connected to the liquid outlet end of the heat absorption passage of the first heat exchanger, and the suction passage of the third heat exchanger is connected. The liquid outlet end of the heat passage is connected with the liquid inlet end of the high temperature tank; the heat release passage of the third heat exchanger is arranged between the steam inlet end of the last stage reheater and the steam outlet of the high temperature reheater The steam inlet end of the heat release passage of the third heat exchanger is connected with the steam outlet end of the high temperature reheater, and the steam inlet end of the last stage reheater is respectively connected with the third heat exchanger. The steam outlet end of the heat release passage of the reheater is connected with the steam outlet end of the high temperature reheater.

Optionally, the flexible operation system of the thermal power unit further includes: a fifth valve body, the fifth valve body is arranged at the steam inlet end of the heat release passage of the third heat exchanger and the outlet of the high temperature reheater. On the pipeline between the steam ends; the sixth valve body, the sixth valve body is arranged on the pipeline between the steam inlet end of the last stage reheater and the steam outlet end of the high temperature reheater .

Optionally, the flexible operation system of the thermal power unit further includes: a low-temperature molten salt pump, which is arranged at the liquid inlet end of the heat absorption passage of the first heat exchanger and the liquid outlet end of the low temperature tank. When connected, the liquid inlet end of the low temperature molten salt pump is connected with the liquid outlet end of the low temperature tank, and the liquid outlet end of the low temperature molten salt pump is connected with the liquid inlet end of the heat absorption passage of the first heat exchanger connected; seventh valve body, the seventh valve body is arranged on the pipeline between the liquid inlet end of the heat absorption passage of the first heat exchanger and the liquid outlet end of the low temperature molten salt pump; high temperature molten salt The high temperature molten salt pump is arranged between the liquid inlet end of the heat release passage of the second heat exchanger and the liquid outlet end of the high temperature tank, and the liquid inlet end of the high temperature molten salt pump is connected to the The liquid outlet end of the high temperature tank is connected, and the liquid outlet end of the high temperature molten salt pump is connected with the liquid inlet end of the heat release passage of the second heat exchanger; the eighth valve body, the eighth valve body is arranged on the On the pipeline between the liquid inlet end of the heat release passage of the second heat exchanger and the liquid outlet end of the high temperature molten salt pump.

Optionally, the flexible operation system of the thermal power unit further includes: a denitration device, the smoke inlet end of the denitration device is connected to the smoke outlet end of the boiler device.

The technical solutions provided by the present disclosure may include the following beneficial effects:

When the power demand is small and the thermal power unit is required to have deep peak shaving, the minimum stable combustion load of the boiler unit is guaranteed, and the output of the boiler unit is reduced by the molten salt heat storage, thereby increasing the peak shaving depth of the thermal power unit and improving the peak shaving of the thermal power unit. Moreover, the heat stored in the molten salt is used to increase the inlet water temperature of the economizer, thereby increasing the temperature of the exhaust end of the boiler device, thereby ensuring the denitrification efficiency of the denitrification device and meeting the smoke exhaust requirements of thermal power units; When the thermal power unit is at its peak, the heat stored in the molten salt is used to ensure the inlet water temperature of the economizer, so as to reduce the heating amount of the outlet steam of the steam turbine to the effluent water of the feed pump, thereby improving the working capacity of the steam turbine and realizing the thermal power unit. Peak power generation. As a result, the flexible operation of the thermal power unit is realized, and the peak shaving capability of the thermal power unit is effectively improved.

Additional aspects and advantages of the present disclosure will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the present disclosure.

Description of drawings

The above and/or additional aspects and advantages of the present disclosure will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

1 is a schematic structural diagram of a flexible operation system for thermal power units based on molten salt heat storage proposed by an embodiment of the present disclosure;

2 is a schematic structural diagram of a flexible operation system for thermal power units based on molten salt heat storage proposed by an embodiment of the present disclosure;

3 is a schematic structural diagram of a flexible operation system for thermal power units based on molten salt heat storage proposed by an embodiment of the present disclosure;

As shown in the figure: 1. Boiler unit, 2. Low temperature tank, 3. High temperature tank, 4. First heat exchanger, 5. Second heat exchanger, 6. Furnace body, 7. Water wall, 8. Separation of steam and water boiler, 9, economizer, 10, high pressure heater, 11, feed water pump, 12, recirculation pump, 13, horizontal low temperature superheater, 14, vertical low temperature superheater, 15, partition screen superheater, 16, high temperature superheater valve, 17, final stage superheater, 18, first valve body, 19, second valve body, 20, third valve body, 21, fourth valve body, 22, high temperature reheater, 23, final stage reheat Heater, 24, third heat exchanger, 25, fifth valve body, 26, sixth valve body, 27, low temperature molten salt pump, 28, seventh valve body, 29, high temperature molten salt pump, 30, eighth valve body.

Detailed ways

Embodiments of the present disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure and should not be construed as a limitation of the present disclosure. On the contrary, the embodiments of the present disclosure include all changes, modifications and equivalents falling within the spirit and scope of the appended claims.

As shown in FIG. 1 , an embodiment of the present disclosure proposes a flexible operation system for thermal power units based on molten salt heat storage, including a boiler device 1 , a low temperature tank 2 , a high temperature tank 3 , a first heat exchanger 4 and a second heat exchanger 5. The liquid inlet end of the heat absorption passage of the first heat exchanger 4 is connected to the liquid outlet end of the low temperature tank 2, and the liquid outlet end of the heat absorption passage of the first heat exchanger 4 is connected to the liquid inlet end of the high temperature tank 3. The steam inlet end of the heat release passage of the heat exchanger 4 is connected to the steam outlet end of the steam-water separator 8 of the boiler unit 1, and the liquid outlet end of the heat release passage of the first heat exchanger 4 is connected to the liquid inlet end of the water wall 7 of the boiler unit 1. , the liquid inlet end of the heat release passage of the second heat exchanger 5 is connected to the liquid outlet end of the high temperature tank 3, the liquid outlet end of the heat release passage of the second heat exchanger 5 is connected to the liquid inlet end of the low temperature tank 2, and the second heat exchanger 5 is connected to the liquid inlet end of the low temperature tank 2. The liquid inlet end of the heat absorption passage of the heat exchanger 5 is connected to the liquid outlet end of the feed pump 11 of the boiler unit 1 , and the liquid outlet end of the heat absorption passage of the second heat exchanger 5 is connected to the liquid inlet end of the economizer 9 of the boiler unit 1 .

Therefore, as shown in FIG. 2 , when the electricity demand is small, the boiler device 1 is at the minimum stable combustion load, and the low-temperature molten salt enters the high-temperature tank 3 from the low-temperature tank 2 through the heat absorption passage of the first heat exchanger 4 , and part of the steam in the steam-water separator 8 enters the water-cooled wall 7 after passing through the heat release path of the first heat exchanger 4, so that the heat in part of the steam in the steam-water separator 8 is released into the low-temperature molten salt, The low temperature molten salt is changed into high temperature molten salt, and the high temperature molten salt is stored in the high temperature tank 3;

Wherein, as shown in FIG. 1 , when the temperature of the exhaust end of the boiler device 1 is low, the low-temperature molten salt is heated by part of the steam in the steam-water separator 8 , and the high-temperature molten salt in the high-temperature tank 3 passes through the second heat exchanger 5 . into the low temperature tank 2, and part of the effluent from the feed pump 11 enters the economizer 9 after passing through the heat absorption path of the second heat exchanger 5, so that the heat of the high temperature molten salt is released into the economizer 9. Part of the effluent from the feed water pump 11 enters the economizer 9 after being heated.

As shown in FIG. 3 , when the electricity demand is large, the steam in the steam-water separator 8 does not enter the heat release path of the first heat exchanger 4 , and the high-temperature molten salt in the high-temperature tank 3 passes through the second heat exchanger 5 . After the heat release passage, it enters into the low temperature tank 2, and all the effluent of the feed pump 11 enters the economizer 9 after passing through the heat absorption passage of the second heat exchanger 5, so that the heat of the high temperature molten salt is released to the feeder. All the effluent of the water pump 11 and the whole effluent of the feed pump 11 are heated and then enter the economizer 9 .

It can be understood that when the power demand is small and the thermal power unit is required to have deep peak shaving, the minimum stable combustion load of the boiler unit 1 is guaranteed, and the output of the boiler unit 1 is reduced through the molten salt heat storage, thereby increasing the thermal power unit’s peak shaving depth. , improve the peak shaving ability of thermal power units, and use the heat stored in molten salt to increase the inlet water temperature of the economizer 9, thereby increasing the temperature of the flue gas outlet of the boiler device 1, thereby ensuring the denitration efficiency of the denitrification device, and meeting the requirements of the thermal power unit. Smoke exhaust requirements; when the power demand is large and the thermal power unit is at its peak, the heat stored in the molten salt is used to ensure the inlet water temperature of the economizer 9, so as to reduce the heating capacity of the outlet steam of the steam turbine to the outlet water of the feed pump 11, thereby Improve the working ability of steam turbines and realize the peak power generation of thermal power units. As a result, the flexible operation of the thermal power unit is realized, and the peak shaving capability of the thermal power unit is effectively improved.

Among them, part of the steam in the steam-water separator 8 releases heat and enters the water-cooled wall 7, thereby increasing the flow of the working medium in the water-cooling wall 7, reducing the steam volume of the boiler device 1, reducing the output of the boiler device 1, and then increasing thermal power. The peak shaving depth of the unit.

It should be noted that the first heat exchanger 4 and the second heat exchanger 5 both include a heat absorption channel and a heat release channel for heat exchange. The heat absorption channel and the heat release channel can exchange heat directly or through The heat transfer medium transfers heat indirectly.

As shown in FIG. 1 , in some embodiments, the boiler device 1 includes a furnace body 6 , a water wall 7 , a steam-water separator 8 , an economizer 9 , a high-pressure heater 10 , a feed pump 11 and a superheater group, and the water wall 7 It is arranged on the inner wall of the furnace body 6, the liquid outlet end of the steam-water separator 8 is connected with the liquid inlet end of the water cooling wall 7, the liquid inlet end of the steam water separator 8 is connected with the liquid outlet end of the water cooling wall 7, and the economizer 9 is provided In the smoke outlet end of the furnace body 6, the liquid outlet end of the economizer 9 is connected with the liquid inlet end of the water wall 7, the liquid outlet end of the high pressure heater 10 is connected with the liquid inlet end of the economizer 9, and the high pressure heater The steam inlet end of 10 is respectively connected with the steam outlet end of the high pressure cylinder of the steam turbine and the steam outlet end of the medium pressure cylinder of the steam turbine, the liquid outlet end of the feed pump 11 is connected with the liquid inlet end of the high pressure heater 10, and the superheater group is arranged in the furnace body. 6, the steam inlet end of the superheater group is connected with the steam outlet end of the steam-water separator 8, and the steam outlet end of the superheater group is connected with the steam inlet end of the high pressure cylinder.

It can be understood that the water-cooled wall 7 absorbs the radiant heat released by the flame and high-temperature flue gas in the furnace body 6, and the water or steam in the water-cooled wall 7 enters the steam-water separator 8 for steam-water separation, and the water in the steam-water separator 8 returns. Continue to use it in the water wall 7. When the electricity demand is small, as shown in Figure 2, the steam in the steam-water separator 8 enters the heat release path of the first heat exchanger 4 for heat release, so as to reduce the boiler size. The output of the device 1; when the electricity demand is large, as shown in Figure 3, all the steam in the steam-water separator 8 enters the superheater group to increase the output of the boiler device 1.

When the electricity demand is small and the temperature of the exhaust end of the boiler device 1 is relatively high, as shown in FIG. 2 , the external water or deoxygenated water is pressurized and transported by the feed pump 11 and passes through the high-pressure heater 10 and the economizer 9 in sequence. Afterwards, it enters into the water cooling wall 7 to ensure the water supply of the boiler device 1; when the electricity demand is small and the temperature of the exhaust end of the boiler device 1 is low, as shown in Figure 1, part of the external water or deoxygenated water is supplied to The water pump 11 is pressurized and transported and enters the water wall 7 after passing through the high pressure heater 10 and the economizer 9 in sequence. The rest of the external water or deoxygenated water is pressurized and transported by the pump 11 and passes through the second heat exchanger 5 for heat absorption. The passage and economizer 9 enter into the water cooling wall 7 to increase the temperature of the flue gas outlet of the boiler device 1; when the demand for electricity is high, as shown in Figure 3, the external water or deoxygenated water is increased by the feed pump 11. It is transported under pressure and sequentially passes through the heat absorption passage of the second heat exchanger 5 and the economizer 9 and then enters the water cooling wall 7 to increase the output of the boiler device 1 .

It should be noted that the steam turbine includes a high-pressure cylinder, a medium-pressure cylinder and a low-pressure cylinder, and the main steam generated by the boiler unit 1 passes through the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder in turn and enters the condenser after performing work, and the condenser will perform work. The latter steam is condensed into condensed water, and the condensed water is heated by a low-pressure heater and then enters the deaerator, and the effluent of the deaerator is deaerated water. Among them, the low-pressure heater heats the condensed water through the steam outlet of the medium-pressure cylinder and the low-pressure cylinder, and the heated steam enters the liquid outlet of the condenser. The deaerated water is heated, and the heated steam enters the liquid inlet end of the deaerator.

As shown in FIG. 1 , in some embodiments, the flexible operation system of the thermal power unit further includes a recirculation pump 12 , and the recirculation pump 12 is arranged at the liquid outlet end of the heat absorption passage of the first heat exchanger 4 and the liquid inlet of the water cooling wall 7 The liquid inlet end of the recirculation pump 12 is connected with the liquid outlet end of the heat absorption passage of the first heat exchanger 4 , and the liquid outlet end of the recirculation pump 12 is connected with the liquid inlet end of the water cooling wall 7 .

It can be understood that the recirculation pump 12 pressurizes and transports the effluent water from the heat absorption passage of the first heat exchanger 4 to the water cooling wall 7 to ensure stable heat release of part of the steam in the steam-water separator 8 .

As shown in FIG. 1, in some embodiments, the superheater group includes a horizontal low temperature superheater 13, a vertical low temperature superheater 14, a partition screen superheater 15, a high temperature superheater 16 and a final stage superheater 17, and the horizontal low temperature superheater 13 The steam inlet end is connected with the steam outlet end of the steam-water separator 8, the steam inlet end of the vertical low temperature superheater 14 is connected with the steam outlet end of the horizontal low temperature superheater 13, and the steam inlet end of the partition screen superheater 15 is connected with the vertical low temperature superheater. The steam outlet end of 14 is connected, the steam inlet end of the high temperature superheater 16 is connected with the steam outlet end of the partition screen superheater 15, the steam inlet end of the final stage superheater 17 is connected with the steam outlet end of the high temperature superheater 16, and the final stage superheater 17 is connected with the steam outlet end of the high temperature superheater 16. The steam outlet end of the superheater 17 is connected to the steam inlet end of the high pressure cylinder of the steam turbine;

Among them, the partition screen superheater 15, the high temperature superheater 16, the final stage superheater 17, the vertical low temperature superheater 14, the horizontal low temperature superheater 13 and the economizer 9 are along the direction from the furnace chamber of the furnace body 6 to the smoke outlet end of the furnace body 6. distributed sequentially.

It can be understood that the steam in the steam-water separator 8 passes through the horizontal low-temperature superheater 13, the vertical low-temperature superheater 14, the partition screen superheater 15, the high-temperature superheater 16 and the final superheater 17, and then is heated to meet the requirements of the high-pressure cylinder of the steam turbine. The main steam, the main steam enters the high pressure cylinder of the steam turbine to do work, so as to realize the power generation of the thermal power unit.

As shown in FIG. 1 , in some embodiments, the flexible operation system of the thermal power unit further includes a first valve body 18 , a second valve body 19 , a third valve body 20 and a fourth valve body 21 , and the first valve body 18 is arranged on the On the pipeline between the steam outlet end of the steam-water separator 8 and the steam inlet end of the heat release passage of the first heat exchanger 4, the second valve body 19 is arranged on the steam outlet end of the steam-water separator 8 and the horizontal low temperature superheater 13. The third valve body 20 is arranged on the pipeline between the inlet end of the feed pump 11 and the inlet end of the high-pressure heater 10, and the fourth valve body 21 is arranged on the pipeline between the inlet end of the feed pump 11 and the inlet end of the high pressure heater 10. 11 is connected to the pipeline between the liquid outlet end of the second heat exchanger 5 and the liquid inlet end of the heat absorption passage of the second heat exchanger 5 .

It can be understood that when the electricity demand is small, as shown in FIG. 2 , the opening degrees of the first valve body 18 and the second valve body 19 are adjusted, so that part of the steam in the steam-water separator 8 enters the first heat exchanger The heat is released in the heat release passage of 4, and the rest of the steam enters the horizontal low temperature superheater 13, the vertical low temperature superheater 14, the partition screen superheater 15, the high temperature superheater 16 and the final superheater 17 for heat absorption. At the same time, the boiler When the temperature of the smoke outlet of the device 1 is relatively high, as shown in Figure 2, the third valve body 20 is opened, and the fourth valve body 21 is closed, so that all the effluent water of the feed pump 11 enters the high pressure heater 10 to absorb heat, and the boiler device When the temperature of the smoke outlet of 1 is low, as shown in FIG. 1, adjust the opening of the third valve body 20 and the fourth valve body 21, so that part of the water from the feed pump 11 enters the high pressure heater 10 to absorb heat, and the rest The effluent enters the heat absorption passage of the second heat exchanger 5 to absorb heat.

When the demand for electricity is large, as shown in FIG. 3 , the first valve body 18 and the third valve body 20 are closed, and the second valve body 19 and the fourth valve body 21 are opened, so that all the steam in the steam-water separator 8 is sequentially Enter the horizontal low temperature superheater 13, the vertical low temperature superheater 14, the partition screen superheater 15, the high temperature superheater 16 and the final stage superheater 17 for heat absorption, so that all the water from the feed pump 11 enters the second heat exchanger 5 absorbs heat in the heat-absorbing path.

Therefore, through the arrangement of the first valve body 18 , the second valve body 19 , the third valve body 20 and the fourth valve body 21 , it is convenient for the steam in the steam-water separator 8 to pass through the heat release passage of the first heat exchanger 4 and level with The distribution between the low-temperature superheaters 13 and the distribution of the effluent from the feed water pump 11 between the high-pressure heater 10 and the heat absorption passage of the second heat exchanger 5 make the overall use more convenient.

As shown in FIG. 1 , in some embodiments, the boiler device 1 further includes a high temperature reheater 22 and a final stage reheater 23 , the high temperature reheater 22 is arranged in the furnace body 6 , and the high temperature reheater 22 is located at the end Between the stage superheater 17 and the vertical low temperature superheater 14, the steam inlet end of the high temperature reheater 22 is connected to the steam outlet end of the high pressure cylinder, the final stage reheater 23 is arranged in the furnace body 6, and the final stage reheater 23 is located between the final stage superheater 17 and the high temperature reheater 22, the steam inlet end of the final stage reheater 23 is connected to the steam outlet end of the high temperature reheater 22, and the steam outlet end of the final stage reheater 23 is connected to the middle The inlet end of the pressure cylinder is connected.

It can be understood that the steam output from the high-pressure cylinder of the steam turbine passes through the high-temperature reheater 22 and the final-stage reheater 23 in turn and is heated into reheated steam that meets the use of the intermediate-pressure cylinder of the steam turbine, and the reheated steam enters the intermediate-pressure cylinder of the steam turbine. Doing work in order to realize the power generation of thermal power units.

As shown in FIG. 1 , in some embodiments, the flexible operation system of the thermal power unit further includes a third heat exchanger 24 , and the heat absorption passage of the third heat exchanger 24 is arranged at the liquid outlet of the heat absorption passage of the first heat exchanger 4 Between the end connected with the liquid inlet end of the high temperature tank 3, the liquid inlet end of the heat absorption passage of the third heat exchanger 24 is connected with the liquid outlet end of the heat absorption passage of the first heat exchanger 4, and the suction passage of the third heat exchanger 24 The liquid outlet end of the heat passage is connected to the liquid inlet end of the high temperature tank 3, and the heat release passage of the third heat exchanger 24 is arranged between the steam inlet end of the final stage reheater 23 and the steam outlet end of the high temperature reheater 22. , the steam inlet end of the heat release passage of the third heat exchanger 24 is connected to the steam outlet end of the high temperature reheater 22, and the steam inlet end of the last stage reheater 23 is respectively connected with the steam outlet end of the heat release passage of the third heat exchanger 24 The end is connected to the steam outlet end of the high temperature reheater 22 .

Therefore, when the electricity demand is small, as shown in FIG. 2 , the boiler device 1 is at the minimum stable combustion load, and the low-temperature molten salt passes through the heat-absorbing passage of the first heat exchanger 4 and the third heat exchanger in sequence from the low-temperature tank 2 24 enters the high temperature tank 3, and part of the outlet steam from the high temperature reheater 22 enters the final reheater 23 after passing through the heat release passage of the third heat exchanger 24, and the rest of the outlet steam directly enters to the last stage reheater 23 , so that part of the heat of the steam from the high temperature reheater 22 is released to the high temperature molten salt in the heat absorption passage of the third heat exchanger 24 , so that the high temperature molten salt is further heated and stored. in high temperature tank 3.

When the demand for electricity is large, as shown in FIG. 3 , all the outlet steam from the high temperature reheater 22 directly enters the last stage reheater 23 to increase the output of the boiler device 1 .

It is understandable that when the power demand is small and the thermal power unit is required to have deep peak regulation, the minimum stable combustion load of the boiler unit 1 is guaranteed, and the output of the boiler unit 1 is further reduced by the molten salt heat storage, thereby increasing the thermal power unit again. peak depth, and further improve the peak shaving capability of thermal power units.

It should be noted that the third heat exchanger 24 includes a heat absorption channel and a heat release channel for heat exchange, and the heat absorption channel and the heat release channel can exchange heat directly or indirectly through a heat conduction medium.

As shown in FIG. 1 , in some embodiments, the flexible operation system of the thermal power unit further includes a fifth valve body 25 and a sixth valve body 26 . The sixth valve body 26 is arranged on the pipe between the steam inlet end of the final stage reheater 23 and the steam outlet end of the high temperature reheater 22 on the pipe between the end of the valve and the steam outlet end of the high temperature reheater 22 on the way.

It can be understood that when the electricity demand is small, as shown in FIG. 2 , the opening degrees of the fifth valve body 25 and the sixth valve body 26 are adjusted, so that part of the steam from the high temperature reheater 22 enters the third heat exchange. Heat is released in the reheater 24, and the rest of the outlet steam directly enters the final reheater 23 to absorb heat.

When the demand for electricity is large, as shown in FIG. 3 , the fifth valve body 25 is closed and the sixth valve body 26 is opened, so that all the outlet steam from the high temperature reheater 22 directly enters the final stage reheater 23 to absorb heat .

Therefore, the arrangement of the fifth valve body 25 and the sixth valve body 26 facilitates the distribution of the steam in the high temperature reheater 22 between the heat release passage of the third heat exchanger 24 and the last stage reheater 23, so that the The overall use is more convenient.

As shown in FIG. 1, in some embodiments, the flexible operation system of the thermal power unit further includes a low temperature molten salt pump 27, a seventh valve body 28, a high temperature molten salt pump 29 and an eighth valve body 30, and the low temperature molten salt pump 27 is arranged at Between the liquid inlet end of the heat absorption passage of the first heat exchanger 4 and the liquid outlet end of the low temperature tank 2, the liquid inlet end of the low temperature molten salt pump 27 is connected with the liquid outlet end of the low temperature tank 2, and the liquid inlet end of the low temperature molten salt pump 27 is connected. The liquid outlet end is connected to the liquid inlet end of the heat absorption passage of the first heat exchanger 4 , and the seventh valve body 28 is arranged at the liquid inlet end of the heat absorption passage of the first heat exchanger 4 and is connected to the liquid outlet end of the low temperature molten salt pump 27 . On the pipeline between, the high temperature molten salt pump 29 is arranged between the liquid inlet end of the heat release passage of the second heat exchanger 5 and the liquid outlet end of the high temperature tank 3, and the liquid inlet end of the high temperature molten salt pump 29 is connected to the high temperature tank. The liquid outlet end of 3 is connected, the liquid outlet end of the high temperature molten salt pump 29 is connected with the liquid inlet end of the heat release passage of the second heat exchanger 5, and the eighth valve body 30 is arranged at the inlet end of the heat release passage of the second heat exchanger 5. On the pipeline between the liquid end and the liquid outlet end of the high-temperature molten salt pump 29 .

It can be understood that the low temperature molten salt in the low temperature tank 2 is pressurized and transported by the low temperature molten salt pump 27 and enters the high temperature through the heat absorption passage of the first heat exchanger 4 and the heat absorption passage of the third heat exchanger 24 in sequence. In the tank 3, in order to ensure the stable heat absorption of the low temperature molten salt, the high temperature molten salt in the high temperature tank 3 is pressurized and transported by the high temperature molten salt pump 29 and enters the low temperature tank 2 after passing through the heat release path of the third heat exchanger 24. , in order to ensure the stable heat release of high temperature molten salt.

Through the arrangement of the seventh valve body 28 and the eighth valve body 30 , it is convenient to control the on-off of the passage between the low temperature tank 2 and the high temperature tank 3 , and the overall use is more convenient.

When the electricity demand is small, as shown in FIG. 2 , the low-temperature molten salt pump 27 and the seventh valve body 28 are turned on, so that the low-temperature molten salt in the low-temperature tank 2 enters the high-temperature tank 3 . When the temperature is low, turn on the high-temperature molten salt pump 29 and the eighth valve, so that the high-temperature molten salt in the high-temperature tank 3 enters into the low-temperature tank 2, and when the temperature of the smoke outlet of the boiler device 1 is high, close the high-temperature molten salt pump 29 and the eighth valve. Eighth valve.

When the demand for electricity is large, as shown in FIG. 3, the high-temperature molten salt pump 29 and the eighth valve are opened, so that the high-temperature molten salt in the high-temperature tank 3 enters the low-temperature tank 2, and the low-temperature molten salt pump 27 and the first valve are closed at the same time. Seven valve bodies 28 .

It should be noted that the first valve body 18 , the second valve body 19 , the third valve body 20 , the fourth valve body 21 , the fifth valve body 25 , the sixth valve body 26 , the seventh valve body 28 and the eighth valve body The body 30 may be a manual switch valve or an electromagnetic switch valve.

In some embodiments, the flexible operation system of the thermal power unit further includes a denitration device, and the smoke inlet end of the denitration device is connected to the smoke outlet end of the boiler device 1 .

It can be understood that the flue gas discharged from the boiler unit 1 is denitrified by the denitrification unit and then discharged to the outside to meet the smoke exhaust requirements of the thermal power unit. It is higher than the minimum inlet flue gas temperature of the denitrification device, thus ensuring the efficient denitrification of the denitration device.

It should be noted that, in the description of the present disclosure, the terms "first", "second", etc. are only used for description purposes, and cannot be understood as indicating or implying relative importance. Also, in the description of the present disclosure, unless stated otherwise, "plurality" means two or more.

Any description of a process or method in the flowcharts or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing a specified logical function or step of the process , and the scope of the preferred embodiments of the present disclosure includes alternative implementations in which the functions may be performed out of the order shown or discussed, including performing the functions substantially concurrently or in the reverse order depending upon the functions involved, which should It is understood by those skilled in the art to which the embodiments of the present disclosure pertain.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structures, materials, or features are included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present disclosure have been shown and described above, it should be understood that the above-described embodiments are exemplary and should not be construed as limitations of the present disclosure, and those of ordinary skill in the art may interpret the above-described embodiments within the scope of the present disclosure. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (10)

1. a thermal power unit flexible operation system based on molten salt heat storage, is characterized in that, comprising: boiler plant, low temperature tank, high temperature tank, the first heat exchanger and the second heat exchanger; The liquid inlet end of the heat absorption passage of the first heat exchanger is connected with the liquid outlet end of the low temperature tank, and the liquid outlet end of the heat absorption passage of the first heat exchanger is connected with the liquid inlet end of the high temperature tank, The steam inlet end of the heat release passage of the first heat exchanger is connected to the steam outlet end of the steam-water separator of the boiler device, and the liquid outlet end of the heat release passage of the first heat exchanger is connected to the water wall of the boiler device The liquid inlet end is connected; The liquid inlet end of the heat release passage of the second heat exchanger is connected to the liquid outlet end of the high temperature tank, and the liquid outlet end of the heat release passage of the second heat exchanger is connected to the liquid inlet end of the low temperature tank, The liquid inlet end of the heat absorption passage of the second heat exchanger is connected to the liquid outlet end of the feed water pump of the boiler device, and the liquid outlet end of the heat absorption passage of the second heat exchanger is connected to the economizer of the boiler device connected to the liquid inlet. 2. the thermal power unit flexible operation system based on molten salt heat storage according to claim 1, is characterized in that, described boiler plant comprises: furnace body; a water cooling wall, the water cooling wall is arranged on the inner wall of the furnace body; In the steam-water separator, the liquid-out end of the steam-water separator is connected with the liquid-inlet end of the water-cooling wall, and the liquid-inlet end of the steam-water separator is connected with the liquid-outlet end of the water-cooling wall; the economizer, the economizer is arranged in the smoke outlet end of the furnace body, and the liquid outlet end of the economizer is connected with the liquid inlet end of the water cooling wall; a high pressure heater, the liquid outlet end of the high pressure heater is connected with the liquid inlet end of the economizer, the steam inlet end of the high pressure heater is respectively connected with the steam outlet end of the high pressure cylinder of the steam turbine and the medium pressure of the steam turbine The steam outlet end of the cylinder is connected; For the feed water pump, the liquid outlet end of the feed water pump is connected to the liquid inlet end of the high-pressure heater; A superheater group, the superheater group is arranged in the furnace body, the steam inlet end of the superheater group is connected with the steam outlet end of the steam-water separator, and the steam outlet end of the superheater group is connected with the high pressure The inlet end of the cylinder is connected. 3. the thermal power unit flexible operation system based on molten salt heat storage according to claim 2, is characterized in that, described thermal power unit flexible operation system also comprises: A recirculation pump, the recirculation pump is arranged between the liquid outlet end of the heat absorption passage of the first heat exchanger and the liquid inlet end of the water cooling wall, and the liquid inlet end of the recirculation pump is connected to the liquid inlet end of the water cooling wall. The liquid outlet end of the heat absorption passage of the first heat exchanger is connected, and the liquid outlet end of the recirculation pump is connected with the liquid inlet end of the water cooling wall. 4. the thermal power unit flexible operation system based on molten salt heat storage according to claim 2, is characterized in that, described superheater group comprises: a horizontal low temperature superheater, the steam inlet end of the horizontal low temperature superheater is connected with the steam outlet end of the steam-water separator; a vertical low temperature superheater, the steam inlet end of the vertical low temperature superheater is connected with the steam outlet end of the horizontal low temperature superheater; a separation screen superheater, the steam inlet end of the separation screen superheater is connected with the steam outlet end of the vertical low temperature superheater; a high temperature superheater, the steam inlet end of the high temperature superheater is connected with the steam outlet end of the partition screen superheater; final stage superheater, the steam inlet end of the final stage superheater is connected with the steam outlet end of the high temperature superheater, and the steam outlet end of the final stage superheater is connected with the steam inlet end of the high pressure cylinder of the steam turbine; Wherein, the partition screen superheater, the high temperature superheater, the last stage superheater, the vertical low temperature superheater, the horizontal low temperature superheater and the economizer are located along the furnace of the furnace body. They are distributed in sequence to the direction of the smoke outlet end of the furnace body. 5. the thermal power unit flexible operation system based on molten salt heat storage according to claim 4, is characterized in that, described thermal power unit flexible operation system also comprises: a first valve body, the first valve body is arranged on the pipeline between the steam outlet end of the steam-water separator and the steam inlet end of the heat release passage of the first heat exchanger; a second valve body, the second valve body is arranged on the pipeline between the steam outlet end of the steam-water separator and the steam inlet end of the horizontal low-temperature superheater; a third valve body, the third valve body is arranged on the pipeline between the liquid outlet end of the feed pump and the liquid inlet end of the high-pressure heater; The fourth valve body is arranged on the pipeline between the liquid outlet end of the feed pump and the liquid inlet end of the heat absorption passage of the second heat exchanger. 6. the thermal power unit flexible operation system based on molten salt heat storage according to claim 4, is characterized in that, described boiler plant also comprises: A high temperature reheater, the high temperature reheater is arranged in the furnace body, and the high temperature reheater is located between the last stage superheater and the vertical low temperature superheater, and the feed of the high temperature reheater is The steam end is connected with the steam outlet end of the high pressure cylinder; A final-stage reheater, the final-stage reheater is arranged in the furnace body, and the final-stage reheater is located between the final-stage superheater and the high-temperature reheater, and the final-stage reheater is The steam inlet end of the reheater is connected with the steam outlet end of the high temperature reheater, and the steam outlet end of the last stage reheater is connected with the steam inlet end of the medium pressure cylinder. 7. the thermal power unit flexible operation system based on molten salt heat storage according to claim 6, is characterized in that, described thermal power unit flexible operation system also comprises: the 3rd heat exchanger; The heat absorption passage of the third heat exchanger is arranged between the liquid outlet end of the heat absorption passage of the first heat exchanger and the liquid inlet end of the high temperature tank, and the heat absorption passage of the third heat exchanger is connected. The liquid inlet end of the passage is connected with the liquid outlet end of the heat absorption passage of the first heat exchanger, and the liquid outlet end of the heat absorption passage of the third heat exchanger is connected with the liquid inlet end of the high temperature tank; The heat release passage of the third heat exchanger is arranged between the steam inlet end of the last stage reheater and the steam outlet end of the high temperature reheater, and the heat release passage of the third heat exchanger The steam inlet end is connected with the steam outlet end of the high temperature reheater, and the steam inlet end of the last stage reheater is respectively connected with the steam outlet end of the heat release passage of the third heat exchanger and the high temperature reheater connected to the steam outlet. 8. the thermal power unit flexible operation system based on molten salt heat storage according to claim 7, is characterized in that, described thermal power unit flexible operation system also comprises: a fifth valve body, the fifth valve body is arranged on the pipeline between the steam inlet end of the heat release passage of the third heat exchanger and the steam outlet end of the high temperature reheater; The sixth valve body is arranged on the pipeline between the steam inlet end of the last stage reheater and the steam outlet end of the high temperature reheater. 9. according to the thermal power plant flexible operation system based on molten salt heat storage described in any one of the claims 1-8, it is characterized in that, described thermal power plant flexible operation system also comprises: A low temperature molten salt pump, the low temperature molten salt pump is arranged between the liquid inlet end of the heat absorption passage of the first heat exchanger and the liquid outlet end of the low temperature tank, and the liquid inlet end of the low temperature molten salt pump is connected is connected with the liquid outlet end of the low temperature tank, and the liquid outlet end of the low temperature molten salt pump is connected with the liquid inlet end of the heat absorption passage of the first heat exchanger; a seventh valve body, the seventh valve body is arranged on the pipeline between the liquid inlet end of the heat absorption passage of the first heat exchanger and the liquid outlet end of the low temperature molten salt pump; High temperature molten salt pump, the high temperature molten salt pump is arranged between the liquid inlet end of the heat release passage of the second heat exchanger and the liquid outlet end of the high temperature tank, and the liquid inlet end of the high temperature molten salt pump is connected is connected with the liquid outlet end of the high temperature tank, and the liquid outlet end of the high temperature molten salt pump is connected with the liquid inlet end of the exothermic passage of the second heat exchanger; The eighth valve body is arranged on the pipeline between the liquid inlet end of the heat release passage of the second heat exchanger and the liquid outlet end of the high temperature molten salt pump. 10. according to the thermal power unit flexible operation system based on molten salt heat storage described in any one in claim 1-8, it is characterized in that, described thermal power unit flexible operation system also comprises: A denitration device, the smoke inlet end of the denitration device is connected with the smoke outlet end of the boiler device.

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