CN-121993270-A - Steam heat storage system of coupled coal motor unit and capacity determination method

CN121993270ACN 121993270 ACN121993270 ACN 121993270ACN-121993270-A

Abstract

The invention provides a steam heat storage system of a coupled coal motor unit and a capacity determination method, and belongs to the technical field of coupled heat storage systems of coal motor units. The invention discloses a coal motor unit in a steam heat storage system of a coupling coal motor unit. The inlet end of the heat recovery system is connected with the outlet end of the turbine unit, and the outlet end of the heat recovery system is connected with the inlet end of the boiler. A steam-water mixed heater, a low-temperature water storage tank and a high-temperature water storage tank are arranged in the steam heat storage system of the coupled coal motor unit. The steam inlet of the steam-water mixing heater is connected with the steam turbine unit, the water inlet of the steam-water mixing heater is connected with the outlet of the low-temperature water storage tank, and the water outlet of the steam-water mixing heater is connected with the inlet of the high-temperature water storage tank. The inlet of the low-temperature water storage tank and the outlet of the high-temperature water storage tank are both connected with the condensed water outlet of the regenerative system. The invention solves the problem of potential safety hazard caused by insufficient deep peak regulation capability in the prior art.

Inventors

Lv kai
CHEN ZHENYU
WANG ZHU
LIU ZEFENG
WU DI
WAN XIAOYAN
WEN TING
XUE CHAONAN
WANG CHAOYANG
MA GUOFENG
LEI FAN
ZHENG HAO
Man jiufang
JIN SEN
ZHAO YINGQI

Assignees

西安热工研究院有限公司
西安交通大学

Dates

Publication Date: 20260508
Application Date: 20260325

Claims (10)

1. The steam heat storage system of the coupling coal motor group comprises a boiler (1) and a steam turbine group, and is characterized in that the coal motor group also comprises a heat return system; the inlet end of the heat recovery system is connected with the outlet end of the turbine unit, and the outlet end of the heat recovery system is connected with the inlet end of the boiler (1); The steam heat storage system of the coupling coal motor unit is provided with a steam-water mixed heater (14), a low-temperature water storage tank (15) and a high-temperature water storage tank (16), a steam inlet of the steam-water mixed heater (14) is connected with the steam turbine unit, a water inlet of the steam-water mixed heater (14) is connected with an outlet of the low-temperature water storage tank (15), a water outlet of the steam-water mixed heater (14) is connected with an inlet of the high-temperature water storage tank (16), and an inlet of the low-temperature water storage tank (15) and an outlet of the high-temperature water storage tank (16) are both connected with a condensed water outlet of the heat recovery system.
2. The steam heat storage system of a coupled coal motor unit according to claim 1, wherein the steam turbine unit comprises a high pressure cylinder (2), a medium pressure cylinder (3) and a low pressure cylinder (4) which are sequentially communicated, and an outlet of the low pressure cylinder (4) is connected with an inlet of a condenser (5).
3. The steam heat storage system of a coupled coal motor unit according to claim 1, wherein the heat recovery system comprises a condensate pump (6), a low-pressure heater unit (7), a deaerator (8), a water supply pump unit (9) and a high-pressure heater unit (10) which are sequentially communicated with the outlet of a condenser (5), and the outlet of the high-pressure heater unit (10) is connected with the inlet of a boiler (1).
4. The steam heat storage system of a coupled coal motor unit according to claim 1, wherein the coal motor unit is further provided with a heat supply regulating and controlling component for regulating and controlling heat supply parameters, and coupling of power generation and heat supply is achieved.
5. The steam heat storage system of the coupled coal motor unit according to claim 4, wherein the heat supply regulation and control assembly comprises a medium-low pressure communicating pipe heat supply butterfly valve (11), a steam extraction valve group (12) and a low pressure cylinder cooling steam regulating valve (13), the medium-low pressure communicating pipe heat supply butterfly valve (11) is arranged on communicating pipes of the medium pressure cylinder (3) and the low pressure cylinder (4), the steam extraction valve group (12) is arranged between a steam extraction port of the medium pressure cylinder (3) and a steam inlet of the steam-water mixed heater (14), and the low pressure cylinder cooling steam regulating valve (13) is used for introducing cooling steam into the low pressure cylinder (4).
6. A method for determining the capacity of a steam heat storage system of a coupled coal motor unit, characterized in that a steam heat storage system of a coupled coal motor unit according to any one of claims 1-5 is used, comprising the steps of: Acquiring the water volume stored in the steam heat storage system of the coupled coal motor unit and the daily average time length of the annual low electricity price of the coal motor unit per hour; The heat storage power and the heat storage duration are obtained based on the water volume stored in the steam heat storage system of the coupled coal motor unit and the annual low electricity price daily average duration of the coal motor unit per hour; obtaining heat storage capacity based on the heat storage power and the heat storage duration; Based on the heat storage capacity, the effective water storage capacity of the steam heat storage system of the coupled coal motor unit is obtained.
7. The method for determining the capacity of a steam heat storage system of a coupled coal motor unit according to claim 6, wherein the calculation formula of the effective water storage capacity of the steam heat storage system of the coupled coal motor unit is as follows: Wherein, the In order to couple the effective water storage volume of the steam heat storage system of the coal motor unit, For the heat storage capacity, The specific heat capacity of water stored in the steam heat storage system of the coupled coal motor unit, The temperature difference between the hot water stored in the steam heat storage system of the coupled coal motor unit and the cold water discharged by the steam heat storage system of the coupled coal motor unit is stored, The water density stored for the steam heat storage system of the coupled coal motor unit; Heat storage capacity The calculation formula of (2) is as follows: Wherein N is the heat storage power, Is the heat storage duration; the calculation formula of the heat storage power N is as follows: Wherein, the For the water volume stored in the steam heat storage system of the coupled coal motor unit in each hour, The water stored in the steam heat storage system of the coupled coal motor unit is watertight, The specific heat capacity of water stored in the steam heat storage system of the coupled coal motor unit, The temperature difference between the hot water and the cold water discharged by the steam heat storage system of the coupled coal motor unit is stored in the steam heat storage system of the coupled coal motor unit.
8. The capacity determining method of steam heat accumulating system of coupled coal motor unit of claim 7, heat accumulating period The method is characterized in that the average daily time length value of the low electricity price in the last year of the coal motor unit is obtained in an upward rounding mode.
9. The capacity determining method of the steam heat storage system of the coupled coal motor unit according to claim 8, wherein a calculation formula of the average daily time length of the last annual low electricity price of the coal motor unit is as follows: Wherein, the The average daily time length of the low electricity price of the last year of the coal motor group, For a low electricity price duration of a day within a coal electric motor group statistics period, For a day within the coal motor group statistics period, Is the natural days of the last year of the coal motor group.
10. The method for determining the capacity of a steam heat storage system of a coupled coal motor unit according to claim 9, wherein the coal motor unit counts a low electricity price duration of a day within a period Obtained by the following steps: acquiring the lowest value of the current electricity price and the power supply variation cost of the coal motor group; Comparing the lowest current price value with the coal motor group power supply variation cost, judging that the power low price period exists on the current day if the lowest current price value is smaller than or equal to the coal motor group power supply variation cost of the first set multiple, and judging that the power low price period does not exist on the current day if the lowest current price value is larger than the coal motor group power supply variation cost of the first set multiple; Counting the time of the lowest value of the current day electricity price lower than the second set multiple and the power supply variation cost of the coal motor group in the current day electricity low price period as the low electricity price time of a certain day in the coal motor group counting period 。

Description

Steam heat storage system of coupled coal motor unit and capacity determination method Technical Field The invention belongs to the technical field of coal motor unit coupling heat storage systems, and particularly relates to a steam heat storage system of a coupling coal motor unit and a capacity determination method. Background Along with the continuous acceleration of the construction process of a novel power system, the large-scale grid connection of new energy power generation such as wind and light becomes the core trend of energy transformation. However, the new energy output has obvious intermittence, volatility and unpredictability, and brings great challenges to the safe and stable operation of the power grid, so that the role of the coal motor unit serving as the core support main body of the power grid is changed from the traditional electric quantity supply main body to the flexible adjustment main body in an accelerating way, and the requirement for improving the power generation flexibility is also urgent. At present, core measures for improving the power generation flexibility of the coal motor group are mainly divided into two types, namely, the group is dug and submerged, the load adjusting range is widened through technical means such as optimizing a combustion system and improving control logic, and the like, and the power assisting group is coupled with an energy storage system, and the load fluctuation is stabilized by means of the charge and discharge characteristics of energy storage equipment, so that the power assisting group can quickly respond to the power grid peak shaving requirement. The energy storage system for peak shaving is mostly in a heat storage type, and is suitable for a cogeneration unit. However, for the pure condensing unit and the heating unit in the non-heating period, due to the lack of constraint and support of heating load, flexible peak regulation cannot be realized by means of a heat storage system, and the self-submerged mode can be relied on, and the process is influenced by multiple factors such as the minimum stable combustion load of a boiler, so that the problems of low load capacity (minimum output of 30%Pe), high energy consumption (30%Pe coal consumption increased by about 25%), outstanding deep rapid peak regulation safety problems (vibration of a steam inlet valve, valve rod breakage, blade breakage, rotor crack and the like) exist, and adverse effects on flexible power generation can be brought. For example, patent application document CN119982125A discloses a green electricity heat storage system for reducing the emission intensity of coal electricity and carbon, which uses waste new energy power, takes molten salt as medium, stores the new energy power in high-temperature molten salt, and converts the energy release stage into high-parameter steam to enter a steam turbine for power generation, but the deep peak regulation capability of the green electricity heat storage system is insufficient, which also causes potential safety hazards. Disclosure of Invention The invention aims to provide a steam heat storage system of a coupled coal motor unit and a capacity determination method, which are used for solving the problem of potential safety hazards caused by insufficient deep peak regulation capability in the prior art. In order to achieve the above purpose, the present invention adopts the following technical scheme: In a first aspect, the invention provides a steam heat storage system of a coupled coal motor unit, wherein the coal motor unit comprises a boiler and a steam turbine unit; The inlet end of the heat recovery system is connected with the outlet end of the turbine unit, and the outlet end of the heat recovery system is connected with the inlet end of the boiler; The steam heat storage system of the coupled coal motor unit is internally provided with a steam-water mixed heater, a low-temperature water storage tank and a high-temperature water storage tank, a steam inlet of the steam-water mixed heater is connected with the steam turbine unit, a water inlet of the steam-water mixed heater is connected with an outlet of the low-temperature water storage tank, a water outlet of the steam-water mixed heater is connected with an inlet of the high-temperature water storage tank, and an inlet of the low-temperature water storage tank and an outlet of the high-temperature water storage tank are both connected with a condensed water outlet of the heat recovery system. The invention is further improved in that the steam turbine unit comprises a high-pressure cylinder, a medium-pressure cylinder and a low-pressure cylinder which are sequentially communicated, and an outlet of the low-pressure cylinder is connected with an inlet of a condenser. The invention is further improved in that the heat recovery system comprises a condensate pump, a low-pressure heater group, a deaerator, a water supply pump group and a high-pressure heater group, wherei