Solar-aided coal-fired flexible power generation system and operation method thereof

Patent metadata

Field	Value
Publication number	US-11560879-B2
Application number	US-201917427644-A
Country	US
Kind code	B2
Filing date	Jun 22, 2019
Priority date	Mar 11, 2019
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

A solar-aided coal-fired flexible power generation system and an operating method thereof are provided. The system includes a coal-fired thermal power generation system and a high-temperature heat storage system coupled with solar thermal power generation; wherein a heat storage medium heater is arranged in the boiler flue; the flow rates of heat storage medium entering the solar heat collection device and the heat storage medium heater are adjusted by the regulating valve and the pump, eliminating irradiation fluctuation influences and maintaining stable power; a heat storage medium tank is used for peak shaving to reduce steam turbine output under stable boiler combustion; the flow and temperature of the feedwater entering the heat storage medium and feedwater heat exchanger are adjusted to realize rapid load cycling. The present invention can realize solar and coal-fired generation coupling, reduce coal consumption, and greatly improve the flexibility and economy.

First claim

What is claimed is:

1. A solar-aided coal-fired flexible power generation system, comprising: a coal-fired thermal power generation system and a high-temperature heat storage system coupled with solar thermal power generation; wherein:
the coal-fired thermal power generation system comprises a boiler ( 1 ), a steam turbine high pressure cylinder ( 2 ), a steam turbine middle and low pressure cylinder ( 3 ), a condenser ( 4 ), a condensate pump ( 5 ), a low pressure heater ( 6 ), a deaerator ( 7 ), a feedwater pump ( 8 ) and a high pressure heater and regulating valve group ( 9 ) which are connected in sequence; wherein a heat storage medium heater ( 10 ) is also arranged in a flue of the boiler ( 1 ); a superheated steam outlet of the boiler ( 1 ) is connected with an inlet of the steam turbine high pressure cylinder ( 2 ); a feedwater inlet of the boiler ( 1 ) is connected with a feedwater outlet of the high pressure heater and regulating valve group ( 9 ); a steam outlet of the steam turbine high pressure cylinder ( 2 ) is connected with a steam inlet of the steam turbine middle and low pressure cylinder ( 3 ) of the steam turbine via the boiler ( 1 ); a first-stage steam extraction outlet of the steam turbine middle and low pressure cylinder ( 3 ) of the steam turbine is connected with a steam inlet of the high pressure heater and regulating valve group ( 9 ) through a pipeline, and a second-stage steam extraction outlet of the steam turbine middle and low pressure cylinder ( 3 ) is connected with a steam inlet of the deaerator ( 7 ) through a pipeline, and a third-stage steam extraction outlet of the steam turbine middle and low pressure cylinder ( 3 ) is connected with a steam inlet of the low pressure heater ( 6 ) through a pipeline; a steam outlet of the steam turbine middle and low pressure cylinder ( 3 ) is connected with a steam inlet of the condenser ( 4 ); a water working fluid outlet of the condenser ( 4 ) is connected with a water working fluid inlet of the low pressure heater ( 6 ) through the condensate pump ( 5 ); a water working fluid outlet of the low pressure heater ( 6 ) is connected with a water working fluid inlet of the deaerator ( 7 ); and
the high-temperature heat storage system coupled with solar thermal power generation comprises a solar heat collection device ( 11 ), a heat storage medium pump ( 12 ), a cold heat storage medium tank ( 13 ), a cold-hot heat storage medium tank connection valve ( 14 ), a hot heat storage medium tank ( 15 ), a thermal storage medium tank outlet regulating valve ( 17 ) and a heat storage medium and feedwater heat exchanger ( 16 ) which are connected in sequence, further comprising a solar heat storage medium regulating valve ( 18 ); an inlet of the solar heat collection device ( 11 ) is connected to a cold heat storage medium outlet of the cold heat storage medium tank ( 13 ) through the solar heat storage medium regulating valve ( 18 ) and the heat storage medium pump ( 12 ); the cold heat storage medium outlet of the cold heat storage medium tank ( 13 ) is also connected with an inlet of the heat storage medium heater ( 10 ) through the heat storage medium pump ( 12 ); an outlet of the solar heat collection device ( 11 ) is connected to a right inlet of the hot heat storage medium of the hot heat storage medium tank ( 15 ) through a pipeline; an outlet of the heat storage medium heater ( 10 ) is connected with a left inlet of the hot heat storage medium of the hot heat storage medium tank ( 15 ) through a pipeline; a heat storage medium outlet of the heat storage medium and feedwater heat exchanger ( 16 ) is connected with a cold heat storage medium inlet of the cold heat storage medium tank ( 13 ) through a pipeline, and a heat storage medium inlet of the heat storage medium and feedwater heat exchanger ( 16 ) is connected to an outlet of the hot heat storage medium tank ( 15 ) through the heat storage medium tank outlet regulating valve ( 17 ); a feedwater outlet of the heat storage medium and feedwater heat exchanger ( 16 ) is connected to the feedwater inlet of the boiler ( 1 ) through a pipeline; a feedwater inlet of the heat storage medium and feedwater heat exchanger ( 16 ) is connected to a water working fluid outlet of the feedwater pump ( 8 ); the cold heat storage medium tank ( 13 ) and the hot heat storage medium tank ( 15 ) of the high-temperature heat storage system are connected via the cold-hot heat storage medium tank connection valve ( 14 ).

2. The solar-aided coal-fired flexible power generation system, as recited in claim 1 , wherein the high pressure heater and regulating valve group ( 9 ) is arranged with a first-stage high pressure heater ( 901 ), a second-stage high pressure heater ( 902 ) and a third-stage high pressure heater ( 903 ), and also comprises a first-stage high pressure heater inlet regulating valve ( 904 ), a two-stage high pressure heater inlet regulating valve ( 905 ), a third-stage high pressure heater inlet regulating valve ( 906 ) and a third-stage high pressure heater outlet regulating valve ( 907 ); wherein a feedwater outlet of the third-stage high pressure heater ( 903 ) is the feedwater outlet of the high pressure heater and regulating valve group ( 9 ); a feedwater inlet of the first-stage high pressure heater ( 901 ) is a feedwater inlet of the high pressure heater and regulating valve group ( 9 ); and a feedwater outlet of a first-stage high pressure heater ( 901 ) is connected with a feedwater inlet of the second-stage high pressure heater ( 902 ) through a pipeline; a feedwater outlet of the second-stage high pressure heater ( 902 ) is connected with a feedwater inlet of the third-stage high pressure heater ( 903 ) through a pipeline; the steam outlet of the steam turbine high pressure cylinder ( 2 ) is connected to a superheated steam inlet of the second-stage high pressure heater ( 902 ) through a pipeline; a first-stage steam extraction outlet of the steam turbine high pressure cylinder ( 2 ) is connected with a steam inlet of the third-stage high pressure heater ( 903 ) through a pipeline; a first-stage steam extraction outlet of the steam turbine middle and low pressure cylinder ( 3 ) is connected with a steam inlet of the first-stage high pressure heater ( 901 ) through a pipeline.

3. The solar-aided coal-fired flexible power generation system, as recited in claim 1 , wherein the feedwater inlet of the heat storage medium and feedwater heat exchanger ( 16 ) is connected with the feedwater inlet of the first-stage high pressure heater ( 901 ) through the first-stage high pressure heater inlet regulating valve ( 904 ), and is connected with the feedwater inlet of the second-stage high pressure heater ( 902 ) through the second-stage high pressure heater inlet regulating valve ( 905 ), and is connected with the feedwater inlet of the third-stage high pressure heater ( 903 ) through the third-stage high pressure heater inlet regulating valve ( 906 ), and is also connected with the feedwater outlet of the third-stage high pressure heater ( 903 ) through the third-stage high pressure heater outlet regulating valve ( 907 ); the feedwater outlet of the heat storage medium and feedwater heat exchanger ( 16 ) is also connected with the feedwater outlet of the third-stage high pressure heater ( 903 ).

4. The solar-aided coal-fired flexible power generation system, as recited in claim 1 , wherein the heat storage medium used in the high-temperature heat storage system coupled with solar thermal power generation is the single-phase flow medium such as molten salt or heat transfer oil.

5. The solar-aided coal-fired flexible power generation system, as recited in claim 1 , wherein the temperature of the flue gas at the flue of the boiler ( 1 ) where the heat storage medium heater ( 10 ) is located is between 550° C. and 700° C.

Assignees

• Univ Xi An Jiaotong

Inventors

• Yan Hui
• Liu Ming
• Chong Daotong
• Wang Jinshi
• Chen Weixiong
• Yan Junjie

Classifications

• F01K11/02

  the engines being turbines · CPC title

• F01D15/10 Primary

  Adaptations for driving, or combinations with, electric generators · CPC title

• F03G6/067 Primary

  Binary cycle plants where the fluid from the solar collector heats the working fluid via a heat exchanger · CPC title

• F01K3/12

  having two or more accumulators · CPC title

• Y02E10/46

  Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines · CPC title