CN217538922U - A solar-assisted coal-fired power generation system with deep peak regulation - Google Patents

Abstract

The utility model discloses a solar-assisted coal-fired power generation system with deep peak regulation, comprising a photothermal subsystem and a coal-fired power generation system. The photothermal subsystem includes a solar heat collector, an oil-salt heat exchanger, a cold molten salt tank, Hot molten salt tank, oil storage tank, brine heat exchanger and oil-water heat exchanger; heating the feed water of boilers in coal-fired power generation systems through oil-water heat exchangers; Heat, so as to carry out deep peak regulation; through the oil-salt heat exchanger to store the heat in the molten salt, or release the heat in the molten salt to heat the feed water of the boiler in the coal-fired power generation system through the oil-water heat exchanger. The deep peak-shaving solar-assisted coal-fired power generation system of the utility model ensures that the solar-coal complementary power generation system participates in deep peak-shaving while stabilizing and safe output.

Description

A solar-assisted coal-fired power generation system with deep peak regulation

technical field

The utility model relates to the technical field of solar-coal complementary power generation systems, in particular to a solar-assisted coal-fired power generation system with deep peak regulation.

Background technique

In the new energy utilization technology, the deep coupling of solar thermal power generation and coal-fired power generation system can share steam turbines and other power and power generation equipment, which solves the problem of high initial investment in solar thermal power generation, and can also improve the efficiency of solar thermal power generation; It can reduce the coal consumption of coal-fired units, significantly reduce the consumption of fossil fuels and carbon dioxide emissions, and also reduce the power generation load of coal-fired units and realize flexible operation.

Solar-coal complementary power generation system, also known as solar-assisted coal-fired power generation system, is a thermal system that is deeply coupled by conventional coal-fired power generation system and solar thermal power generation system in the process of photothermal conversion and thermal power conversion. Solar heat is directly or indirectly introduced into the thermal power system to achieve complementary utilization of energy and clean coal-fired power generation. In the existing solar-coal complementary power generation technology, there are four types of solar side, trough type, tower type, dish type and linear Fresnel type, and the coupling with the coal-fired power generation system is also more diverse.

Most of the existing solar-coal complementary power generation systems are not equipped with a heat storage system on the solar side, so the output heat varies with the change of the solar radiation intensity and cannot output stably, although the coal-fired system can supplement the solar side to a certain extent. Power changes, but it has a great impact on the overall stability and safety of the system; systems with heat storage often use solar heat and heat storage for heat exchange, and the heat storage is exchanged with a heat exchanger at a certain stage in the coal-fired power generation system. In this way, the efficiency of solar thermal power generation is low, thus reducing the overall efficiency of the system. In addition, the introduction of solar energy has caused a certain pressure on the power grid to reduce peaking, and it is difficult for the existing solar-coal complementary power generation system to participate in deep peaking while ensuring the stable and safe output of the system.

Utility model content

The purpose of the utility model is to provide a solar-assisted coal-fired power generation system with deep peak regulation, so as to solve the above problems in the prior art and ensure that the solar-coal complementary power generation system can participate in deep peak regulation while stabilizing and safe output.

For achieving the above object, the utility model provides the following scheme:

The utility model provides a solar-assisted coal-fired power generation system with deep peak regulation, comprising a photothermal subsystem and a coal-fired power generation system, wherein the photothermal subsystem includes a solar heat collector, an oil-salt heat exchanger, a cold molten salt tank, hot molten salt tank, oil storage tank, brine heat exchanger and oil-water heat exchanger; the oil outlet of the oil storage tank is communicated with the oil inlet of the solar thermal collector, and the solar thermal collector The oil outlet is communicated with the oil inlet of the oil-water heat exchanger through the first connecting pipe, the oil outlet of the oil-water heat exchanger is communicated with the oil storage tank, and the oil-water heat exchanger is used for heating the fuel. Feed water for boilers in coal power generation systems;

One end of the oil flow channel of the oil-salt heat exchanger is communicated with the first connecting pipe, and the other end is communicated with the oil storage tank, and one end of the salt flow channel of the oil-salt heat exchanger is communicated with the cold melt The salt tank is in communication with the other end of the hot molten salt tank, the cold molten salt tank is in communication with the inlet of the salt flow channel of the brine heat exchanger, and the hot molten salt tank is in communication with the salt flow channel of the brine heat exchanger. The outlet of the salt flow channel is communicated; the extraction steam of the steam turbine in the coal-fired power generation system can be passed into the salt water heat exchanger, and the outlet of the water flow channel of the salt water heat exchanger is communicated with the coal-fired power generation system Drain in the return line.

Preferably, the solar heat collecting device is formed by connecting a plurality of trough solar heat collecting devices in series.

Preferably, the communication pipe between the oil flow channel of the oil-salt heat exchanger and the first connection pipe is a second connection pipe, and the first connection pipe is provided with a first valve and a second valve, so The interface between the second connecting pipe and the first connecting pipe is located between the first valve and the second valve, and the first valve is closer to the oil-water heat exchanger than the second valve, so The second connecting pipe is provided with a third valve; the third valve is a two-way valve, and both the first valve and the second valve are one-way valves.

Preferably, the coal-fired power generation system includes the steam turbine, the generator set, and a condenser, a condensate pump, a shaft seal heater, a deaerator, a feed water pump, a third high-pressure regenerative heater, a second A high-pressure regenerative heater and a first high-pressure regenerative heater, the steam inlet of the condenser is communicated with the steam outlet of the low-pressure cylinder of the steam turbine, and the water outlet of the first high-pressure regenerative heater is connected to the steam outlet of the low-pressure cylinder of the steam turbine. The water supply port of the boiler is connected, the first-stage extraction steam of the high-pressure cylinder of the steam turbine is passed into the first high-pressure regenerative heater, and the second-stage extraction steam of the high-pressure cylinder of the steam turbine is passed into the second high-pressure regenerative heating The extraction steam of the medium pressure cylinder of the steam turbine is passed into the third high-pressure regenerative heater, and four low-pressure regenerative heaters are connected in series between the shaft seal heater and the deaerator. The extraction steam of the low-pressure cylinder is passed into the four low-pressure regenerative heaters.

Preferably, the hydrophobic water outlet of the first high-pressure regenerative heater is also communicated with the water inlet of the second high-pressure regenerative heater, and the hydrophobic water outlet of the second high-pressure regenerative heater passes through a fourth connecting pipe It is communicated with the water inlet of the third high-pressure regenerative heater.

Preferably, the inlet of the water channel of the brine heat exchanger is communicated with the steam outlet of the secondary extraction steam of the high-pressure cylinder of the steam turbine through a third connecting pipe, and a fourth valve is provided on the third connecting pipe; The outlet of the water channel of the brine heat exchanger communicates with the fourth connection pipe.

Preferably, the water outlet of the second high-pressure regenerative heater is communicated with the water inlet of the oil-water heat exchanger, and the water outlet of the oil-water heat exchanger is communicated with the water supply port of the boiler.

The utility model also provides a control method for the above-mentioned deep peak-shaving solar-assisted coal-fired power generation system, comprising the following steps:

S1: First determine whether there is light and whether deep peak shaving is required. If there is light, go to step S2, otherwise go to step S3; when the coal-fired power generation system needs to perform deep peak regulation, the part of the steam turbine in the coal-fired power generation system The extraction steam is passed into the brine heat exchanger to heat the molten salt to realize heat storage. After the extraction and heat exchange, it is returned to the return water pipeline of the coal-fired power generation system for drainage, and the brine is heat exchanged without deep peak regulation. The water inlet of the appliance is closed;

S2: Determine whether the heat Q ₁ collected by the solar heat collector is greater than the heat Q ₂ required by the oil-water heat exchanger to heat the boiler feed water, if Q ₁ >Q ₂ , go to step S2-1, if Q ₁ =Q ₂ , then Go to step S2-2, if Q ₁ <Q ₂ then go to step S2-3;

S2-1: Pass the oil output of the solar heat collector into the oil-water heat exchanger and the oil-salt heat exchanger at the same time, and heat the feed water of the boiler in the coal-fired power generation system through the oil-water heat exchanger , and heat the molten salt through the oil-salt heat exchanger for heat storage;

S2-2: Passing the oil output of the solar heat collector only into the oil-water heat exchanger, and heating the feed water of the boiler in the coal-fired power generation system through the oil-water heat exchanger;

S2-3: only pass the oil from the solar heat collector into the oil-salt heat exchanger, and heat the molten salt through the oil-salt heat exchanger to store heat;

S3: Close the oil outlet of the solar heat collector, use the heat storage of the molten salt in the hot molten salt tank to heat the oil in the oil storage tank through the oil-salt heat exchanger, and use the heated oil to pass through The oil-water heat exchanger heats the feed water of the boiler in the coal-fired power generation system.

The utility model has achieved the following technical effects with respect to the prior art:

The deep peak-shaving solar-assisted coal-fired power generation system of the utility model ensures that the solar-coal complementary power generation system participates in deep peak-shaving while stabilizing and safe output. In the utility model, by adding molten salt heat storage and oil-salt heat exchanger on the light-heat side, the heat collected by the solar heat collecting device is “cut peak and filled valley”, and the stable output is realized through the control and conversion of the operation mode; The addition of brine heat exchangers enables the solar thermal side heat storage system not only to play a role in the solar thermal side, but also to play a role in deep peak shaving to store excess heat. Peak shaving costs. The heat storage system in the utility model, which is composed of cold molten salt tank, hot molten salt tank, oil-salt heat exchanger, brine heat exchanger, etc., can not only realize the stable output of light-heat and coal-fired coupling, but also can participate in the coal-fired unit. In-depth peak shaving, greatly improving the actual efficiency of the solar-coal complementary system.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only of the present invention. For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of a solar-assisted coal-fired power generation system for deep peak regulation of the present invention;

Among them: 100. Solar-assisted coal-fired power generation system for deep peak regulation; 200. Coal-fired power generation system; 300. Photothermal subsystem; 1. Solar heat collector; 2. Oil storage tank; 3. Oil-water heat exchanger; 4 , oil-salt heat exchanger; 5, cold molten salt tank; 6, hot molten salt tank; 7, brine heat exchanger; 8, boiler; 9, high pressure cylinder; 10, medium pressure cylinder; 11, low pressure cylinder; 12, Generator; 13, condenser; 14, condensate water pump; 15, shaft seal heater; 16, low pressure regenerative heater; 17, deaerator; 18, feed water pump; 19, third high pressure regenerative heater; 20 21, the first high pressure regenerative heater; 22, the first valve; 23, the second valve; 24, the third valve; 25, the fourth valve.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The purpose of the utility model is to provide a solar-assisted coal-fired power generation system with deep peak regulation, so as to solve the above problems in the prior art and ensure that the solar-coal complementary power generation system can participate in deep peak regulation while stabilizing and safe output.

In order to make the above objects, features and advantages of the present utility model more clearly understood, the present utility model will be described in further detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1 : this embodiment provides a solar-assisted coal-fired power generation system 100 with deep peak regulation, including a photothermal subsystem 300 and a coal-fired power generation system 200 , and the photothermal subsystem 300 includes a solar heat collector 1, Oil-salt heat exchanger 4, cold molten salt tank 5, hot molten salt tank 6, oil storage tank 2, brine heat exchanger 7 and oil-water heat exchanger 3; oil outlet of oil storage tank 2 and solar heat collector 1 The oil inlet of the solar heat collector 1 is connected with the oil inlet of the oil-water heat exchanger 3 through the first connecting pipe, and the oil outlet of the oil-water heat exchanger 3 is communicated with the oil storage tank 2, and the oil-water exchange The heater 3 is used to heat the feed water of the boiler 8 in the coal-fired power generation system 200;

One end of the oil flow channel of the oil-salt heat exchanger 4 is communicated with the first connecting pipe, and the other end is communicated with the oil storage tank 2. One end of the salt flow channel of the oil-salt heat exchanger 4 is communicated with the cold molten salt tank 5, and the other end Connected with the hot molten salt tank 6, the cold molten salt tank 5 is communicated with the inlet of the salt flow channel of the brine heat exchanger 7, and the hot molten salt tank 6 is communicated with the outlet of the salt flow channel of the brine heat exchanger 7; coal-fired power generation system The extraction steam of the steam turbine in 200 can be passed into the brine heat exchanger 7, and the outlet of the water flow channel of the brine heat exchanger 7 is connected to the return water pipeline in the coal-fired power generation system 200 for draining.

In this embodiment, the solar heat collecting device 1 is formed by using a plurality of trough solar heat collecting devices 1 connected in series. The communication pipe between the oil flow channel of the oil-salt heat exchanger 4 and the first connecting pipe is the second connecting pipe, the first connecting pipe is provided with a first valve 22 and a second valve 23, and the second connecting pipe is connected to the first connecting pipe. The interface of the connecting pipe is located between the first valve 22 and the second valve 23, and the first valve 22 is closer to the oil-water heat exchanger 3 than the second valve 23. The second connecting pipe is provided with a third valve 24; the third valve 24 It is a two-way valve, and both the first valve 22 and the second valve 23 are one-way valves.

The coal-fired power generation system 200 includes a steam turbine, 12 sets of generators, a condenser 13, a condensate water pump 14, a shaft seal heater 15, a deaerator 17, a feed water pump 18, a third high-pressure regenerative heater 19, The second high pressure regenerative heater 20 and the first high pressure regenerative heater 21, the steam inlet of the condenser 13 is connected to the steam outlet of the low pressure cylinder 11 of the steam turbine, and the water outlet of the first high pressure regenerative heater 21 is connected to the boiler The water supply port of The extraction steam of the medium-pressure cylinder 10 is passed into the third high-pressure regenerative heater 19, four low-pressure regenerative heaters 16 are connected in series between the shaft seal heater 15 and the deaerator 17, and the extraction steam of the low-pressure cylinder 11 is passed into Four low pressure regenerative heaters 16 .

The hydrophobic water outlet of the first high-pressure regenerative heater 21 is also communicated with the water inlet of the second high-pressure regenerative heater 20, and the hydrophobic water outlet of the second high-pressure regenerative heater 20 is connected to the third high-pressure regenerative heater through a fourth connection pipe. The water inlet of the heater 19 is communicated.

The inlet of the water channel of the brine heat exchanger 7 is communicated with the steam outlet of the secondary extraction steam of the high-pressure cylinder 9 of the steam turbine through the third connecting pipe, and the third connecting pipe is provided with a fourth valve 25; The outlet of the water channel is communicated with the fourth connection pipe. The water outlet of the second high pressure regenerative heater 20 is communicated with the water inlet of the oil-water heat exchanger 3 , and the water outlet of the oil-water heat exchanger 3 is communicated with the water supply port of the boiler 8 .

It should be noted that, in practical application, this embodiment does not need to be limited, but the outlet of the water flow channel of the brine heat exchanger 7 must be connected to the steam outlet of the secondary extraction steam of the high-pressure cylinder 9 of the steam turbine. It is necessary to make part of the extraction steam of the steam turbine pass through the brine heat exchanger 7 to heat the molten salt for heat storage, and at the same time achieve the purpose of peak regulation; in the same way, it is not necessary to make the oil-water heat exchanger 3 be heated with the first high-pressure regenerative heating. The heaters 21 are connected in parallel so as to replace the first high-pressure regenerative heater 21 to assist the heating of the water supply of the boiler 8. The specific pipeline connection settings can be appropriately adjusted as required. It is only necessary to use the oil-water heat exchanger 3 to assist the heating of the boiler 8. Just give water.

This embodiment also provides a control method for the above-mentioned deep peak-shaving solar-assisted coal-fired power generation system 100, including the following steps:

S1: First determine whether there is light and whether deep peak shaving is required. If there is light, go to step S2; otherwise, go to step S3; The extraction steam is passed into the brine heat exchanger 7 to heat the molten salt to realize heat storage, and after the extraction and heat exchange, it is returned to the return water pipeline of the coal-fired power generation system 200 for draining. the water inlet is closed;

S2: Determine whether the heat Q ₁ collected by the solar heat collector 1 is greater than the heat Q ₂ required by the oil-water heat exchanger 3 to heat the water inlet of the boiler 8 , if Q ₁ >Q ₂ , go to step S2-1, if Q ₁ = Q ₂ , then go to step S2-2, if Q ₁ <Q ₂ , go to step S2-3;

S2-1: Pass the oil from the solar heat collector 1 into the oil-water heat exchanger 3 and the oil-salt heat exchanger 4 at the same time, and heat the feed water of the boiler 8 in the coal-fired power generation system 200 through the oil-water heat exchanger 3, and Heat storage by heating the molten salt through the oil-salt heat exchanger 4;

S2-2: Pass the oil output of the solar heat collector 1 into the oil-water heat exchanger 3 only, and heat the feed water of the boiler 8 in the coal-fired power generation system 200 through the oil-water heat exchanger 3;

S2-3: Only pass the oil from the solar heat collector 1 into the oil-salt heat exchanger 4, and heat the molten salt through the oil-salt heat exchanger 4 to store heat;

S3: Close the oil outlet of the solar thermal collector 1, use the heat storage of the molten salt in the hot molten salt tank 6 to heat the oil in the oil storage tank 2 through the oil-salt heat exchanger 4, and use the heated oil The liquid heats the feed water of the boiler 8 in the coal-fired power generation system 200 through the oil-water heat exchanger 3 .

By configuring hot molten salt tanks of different capacities and switching to use these hot molten salt tanks, it can be ensured that the system switches between steps S2-1 and S2-2 during the day when the system is full of sunshine, and the whole system switches between steps S2-1 and S2-2 at night. In order to operate in the state of step S3, the fluctuation of the light and heat output caused by the operation of step S2-3 should be avoided as much as possible.

In the description of the present invention, it should be noted that the terms "first", "second" and the like are only used for the purpose of description, and should not be construed as indicating or implying relative importance.

In this specification, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; meanwhile, for those of ordinary skill in the art, According to the idea of the present invention, there will be changes in the specific implementation and application scope. In conclusion, the content of this specification should not be construed as a limitation on the present invention.

Claims (7)

1. A solar-assisted coal-fired power generation system for deep peak regulation, characterized in that it includes a photothermal subsystem and a coal-fired power generation system, and the photothermal subsystem includes a solar heat collector, an oil-salt heat exchanger, a cold melting Salt tank, hot molten salt tank, oil storage tank, brine heat exchanger and oil-water heat exchanger; the oil outlet of the oil storage tank is communicated with the oil inlet of the solar heat collecting device, and the solar heat collecting device The oil outlet is communicated with the oil inlet of the oil-water heat exchanger through the first connecting pipe, the oil outlet of the oil-water heat exchanger is communicated with the oil storage tank, and the oil-water heat exchanger is used to heat the oil-water heat exchanger. Feed water for boilers in coal-fired power generation systems; One end of the oil flow channel of the oil-salt heat exchanger is communicated with the first connecting pipe, and the other end is communicated with the oil storage tank, and one end of the salt flow channel of the oil-salt heat exchanger is communicated with the cold melt The salt tank is in communication with the other end of the hot molten salt tank, the cold molten salt tank is in communication with the inlet of the salt flow channel of the brine heat exchanger, and the hot molten salt tank is in communication with the salt flow channel of the brine heat exchanger. The outlet of the salt flow channel is communicated; the extraction steam of the steam turbine in the coal-fired power generation system can be passed into the salt water heat exchanger, and the outlet of the water flow channel of the salt water heat exchanger is communicated with the coal-fired power generation system Drain in the return line. 2 . The solar-assisted coal-fired power generation system for deep peak regulation according to claim 1 , wherein the solar heat collecting device is formed by connecting a plurality of trough solar heat collecting devices in series. 3 . 3 . The solar-assisted coal-fired power generation system for deep peak regulation according to claim 1 , wherein the connecting pipe between the oil flow channel of the oil-salt heat exchanger and the first connecting pipe is the second connecting pipe. 4 . a connecting pipe, the first connecting pipe is provided with a first valve and a second valve, the interface between the second connecting pipe and the first connecting pipe is located between the first valve and the second valve, And the first valve is closer to the oil-water heat exchanger than the second valve, and a third valve is arranged on the second connecting pipe; the third valve is a two-way valve, and the first valve is connected to the second valve. The second valves are all one-way valves. 4 . The solar-assisted coal-fired power generation system for deep peak regulation according to claim 1 , wherein the coal-fired power generation system comprises the steam turbine, the generator set, and the condenser, the condensate pump, the shaft and the connected pipeline in sequence. 5 . Sealed heater, deaerator, feed water pump, third high pressure regenerative heater, second high pressure regenerative heater and first high pressure regenerative heater, the steam inlet of the condenser is connected to the low pressure cylinder of the steam turbine The water outlet of the first high-pressure regenerative heater is connected to the water supply port of the boiler, and the first-stage extraction steam of the high-pressure cylinder of the steam turbine is passed into the first high-pressure regenerative heater, The secondary extraction steam of the high pressure cylinder of the steam turbine is passed into the second high pressure regenerative heater, the extraction steam of the medium pressure cylinder of the steam turbine is passed into the third high pressure regenerative heater, and the shaft seal is heated Four low-pressure regenerative heaters are also connected in series between the deaerator and the deaerator, and the extraction steam from the low-pressure cylinder is passed into the four low-pressure regenerative heaters. 5 . The solar-assisted coal-fired power generation system for deep peak regulation according to claim 4 , wherein the drain water outlet of the first high-pressure regenerative heater is also connected to the inlet of the second high-pressure regenerative heater. 6 . The water outlet is communicated, and the drain water outlet of the second high-pressure regenerative heater is communicated with the water inlet of the third high-pressure regenerative heater through a fourth connecting pipe. 6 . The solar-assisted coal-fired power generation system for deep peak regulation according to claim 5 , wherein the inlet of the water channel of the brine heat exchanger is connected to the second stage of the high-pressure cylinder of the steam turbine through a third connecting pipe. 7 . The steam outlet of the extraction steam is connected, and the third connecting pipe is provided with a fourth valve; the outlet of the water flow channel of the salt water heat exchanger is connected with the fourth connecting pipe. 7 . The solar-assisted coal-fired power generation system for deep peak regulation according to claim 4 , wherein the water outlet of the second high-pressure regenerative heater is in communication with the water inlet of the oil-water heat exchanger, and the The water outlet of the oil-water heat exchanger is communicated with the water supply port of the boiler.

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