CN-115021279-B - Fire-storage combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot

CN115021279BCN 115021279 BCN115021279 BCN 115021279BCN-115021279-B

Abstract

The invention relates to a fire-storage combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot, which comprises a composite energy storage subsystem, a condensate throttling frequency modulation response subsystem, a boiler overshoot control subsystem and a boiler overshoot control subsystem, wherein the composite energy storage subsystem is used for realizing the targeted participation of different types of frequency modulation instruction demands of different types of batteries, the condensate throttling frequency modulation response subsystem is used for participating in auxiliary adjustment when the composite energy storage subsystem cannot meet the power grid frequency modulation response demands, the frequency modulation response subsystem is used for controlling the composite energy storage subsystem, the condensate throttling frequency modulation response subsystem, the boiler overshoot control subsystem and a main steam modulation door of a steam turbine to participate in frequency modulation response together according to received frequency modulation instructions, and the boiler overshoot control subsystem is used for setting overshoot on the basis of load instructions when the frequency modulation response subsystem receives long-term large-amplitude frequency modulation instructions. Compared with the prior art, the invention has the advantages of reducing the power generation coal consumption and equipment abrasion to the greatest extent, prolonging the service life of the battery of the energy storage system, reducing the initial investment cost and the like.

Inventors

ZHU JIAQI
HE BIN
LI QINGYOU
LI RAN
XU ZHIHAI

Assignees

上海申能新动力储能研发有限公司

Dates

Publication Date: 20260505
Application Date: 20220524

Claims (5)

1. The utility model provides a fire that based on compound energy storage, condensate frequency modulation and boiler overshoot stores up united frequency modulation system for improve thermal power generating unit and participate in the frequency modulation response through the load regulation mode of main steam regulating valve throttle, the steam turbine is connected through main steam regulating valve to the boiler, and the low pressure heat exchanger is connected to the steam turbine, and the steam turbine is connected to the one end of condenser, and the low pressure heat exchanger is connected through the condensate pump to the other end, and boiler water supply equipment is connected to the other end of low pressure heat exchanger, its characterized in that includes: The composite energy storage subsystem is used for realizing the targeted participation of different types of batteries in different types of frequency modulation instruction requirements; The condensate throttling frequency modulation response subsystem is used for participating in auxiliary regulation when the composite energy storage subsystem cannot meet the frequency modulation response requirement of the power grid; the frequency modulation response subsystem is used for controlling the composite energy storage subsystem, the condensate throttling frequency modulation response subsystem, the boiler overshoot control subsystem and the main steam modulation door of the steam turbine to participate in frequency modulation response according to the received frequency modulation instruction and the actual output of the unit; the boiler overshoot control subsystem is connected with the adjusting valve between the boiler and the water supply equipment and between the boiler and the coal supply equipment, and is used for setting overshoot on the basis of a load instruction and adjusting the amount of water and coal entering the boiler when the frequency modulation response subsystem receives a long-time and large-amplitude frequency modulation instruction; The frequency modulation response subsystem controls the composite energy storage subsystem, the condensate throttling frequency modulation response subsystem, the boiler overshoot control subsystem and the main steam modulation door of the steam turbine to jointly participate in frequency modulation response according to the received frequency modulation instruction and the actual output of the unit, wherein the joint participation in frequency modulation response comprises joint participation in a primary frequency modulation mode and joint participation in a secondary frequency modulation mode; the frequency modulation response subsystem controls the composite energy storage subsystem, the condensate throttling frequency modulation response subsystem, the boiler overshoot control subsystem and the main steam modulation door according to the received frequency modulation instruction and the actual output of the unit to jointly participate in the frequency modulation response, and comprises the following specific contents of jointly participating in a primary frequency modulation mode: the frequency modulation response subsystem sends an instruction to a BESS controller of the composite energy storage subsystem, and the BESS controller calculates a power set value of the composite energy storage subsystem by combining the first battery charge state and feeds back the set value to the frequency modulation response subsystem; The condensate throttling response module adjusts the condensate flow according to key operation parameters, thereby controlling the steam quantity entering the low-pressure heater and participating in primary frequency modulation response; When the primary frequency modulation requirement exceeds the frequency modulation response capacity of the composite energy storage subsystem and the condensate throttling response module, if the primary frequency modulation requirement is a load reduction requirement, the primary frequency modulation response requirement is met by reducing the opening of the main steam regulating valve; The frequency modulation response subsystem controls the composite energy storage subsystem, the condensate throttling frequency modulation response subsystem, the boiler overshoot control subsystem and the main steam modulation door of the steam turbine to jointly participate in the frequency modulation response according to the received frequency modulation instruction and the actual output of the unit, and comprises the following specific contents of jointly participating in a secondary frequency modulation mode: The frequency modulation response subsystem generates a load demand instruction according to the secondary frequency modulation instruction of the power grid and the actual load of the unit, and transmits the load demand instruction to a BESS controller of the composite energy storage subsystem, and the BESS controller calculates a power set value of the composite energy storage subsystem by combining the charge state of the second battery and feeds back the set value to the frequency modulation response subsystem; The condensation throttling response module adjusts the condensation flow according to the key operation parameters, thereby controlling the steam quantity entering the low-pressure heater to participate in response; when the secondary frequency modulation instruction exceeds the capacities of the composite energy storage subsystem and the condensate throttling response module, if the load is reduced, the opening of the main steam regulating valve is reduced to meet the requirement; When the frequency modulation response subsystem receives the frequency modulation command which is more than 50% of the rated power of the composite energy storage system for two continuous minutes, the secondary frequency modulation command is issued to the boiler overshoot control subsystem, and the boiler overshoot control subsystem superimposes overshoot on the basis of the secondary frequency modulation command, controls the water and coal quantity entering the boiler and overshoot the boiler load of the thermal power generating unit.
2. The fire and storage combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot of claim 1, wherein the composite energy storage subsystem comprises a first battery for participating in short-time high-rate grid frequency modulation instructions, primary frequency modulation, and a second battery for participating in long-time low-rate grid frequency modulation instructions, secondary frequency modulation.
3. The fire and energy combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot of claim 2, wherein the composite energy storage subsystem further comprises a first battery, a second battery, a DC/DC converter, a DC/AC inverter rectifier and a BESS controller, wherein the first battery and the second battery are respectively connected in series with one DC/DC converter, the output ends of the two DC/DC converters are connected with the DC/AC inverter rectifier, the DC/AC inverter rectifier is connected with a high-voltage factory transformer, the high-voltage factory transformer is connected between a generator and a main transformer, one end of the BESS controller is respectively connected with a load, the DC/AC inverter rectifier, the first battery, the second battery and each DC/DC converter, and the other end of the BESS controller is connected with the frequency modulation response subsystem.
4. The fire storage combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot according to claim 3, wherein the condensate throttling frequency modulation response subsystem comprises a condensate throttling response module, a low-pressure heater bypass door and a connecting pipe system, wherein the condensate throttling response module is used for participating in response according to the capability of the condensate throttling frequency modulation response subsystem, the low-pressure heater bypass door is used for adjusting the condensate amount entering a low-pressure heater, the condensate throttling response module is connected with the low-pressure heater bypass door, one end of the low-pressure heater bypass door is connected between the low-pressure heater and a condensate pump, the other end of the low-pressure heater bypass door is connected with a boiler water supply device, and the condensate throttling frequency modulation response subsystem is used for adjusting the condensate amount entering the low-pressure heater by controlling the opening of the low-pressure heater bypass door, so as to indirectly adjust the steam extraction amount of a steam turbine.
5. The fire and storage combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot of claim 2, wherein the first battery is a carbon-based capacitor battery and the second battery is a lithium iron phosphate battery.

Description

Fire-storage combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot Technical Field The invention relates to the technical field of thermal power generating unit frequency modulation, in particular to a fire storage combined frequency modulation system based on composite energy storage, condensate water frequency modulation and boiler overshoot. Background Along with the upgrading of carbon reaching peaks and carbon neutralization targets into national strategy, the economic and social development starts to be comprehensively and environmentally transformed, the installed capacity of new energy power such as wind power, photovoltaic, hydropower and the like further continuously and rapidly increases, and the fluctuation and intermittence of the power generation output of the new energy have increasingly serious influence on the stable operation of the power grid. In order to ensure the safety and stability of the operation of the power grid, the thermal power generating unit receives more frequent frequency modulation instructions as a power grid supporting power source, and the frequency modulation depth requirement is also larger and larger. The thermal power generating unit generally participates in frequency modulation response in a load regulation mode of throttling by a main steam regulating valve, and the mode has the advantages of timely response and large regulation capacity, but also has the defects of large throttling loss, high power generation coal consumption and serious equipment abrasion. In recent years, a fire-storage combined frequency modulation technology appears, as shown in fig. 2, the technology generally adopts a lithium iron phosphate battery energy storage system to assist in the frequency modulation response of a thermal power unit, so as to release the opening of a main throttle valve to a certain extent and reduce the throttle loss of a valve, however, through practical application, the fire-storage combined frequency modulation technology generally has the defects of large battery capacity, high initial investment, short battery life and poor economy, and meanwhile, the capability of releasing the opening of the main throttle valve is limited, and the throttle loss of the valve is not obviously improved. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a fire-storage combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot, the valve of the main steam regulating valve of the thermal power generating unit can be fully opened, so that the power generation coal consumption and equipment abrasion are reduced to the greatest extent, the service lives of batteries of the energy storage systems can be comprehensively prolonged through different types of energy storage systems, and the initial investment cost is reduced. The aim of the invention can be achieved by the following technical scheme: Fire that is based on compound energy storage, condensate frequency modulation and boiler overshoot stores up united frequency modulation system, this system is used for improving thermal power generating unit and participates in the frequency modulation response through the load regulation mode of main steam regulating valve throttle, and the steam turbine is connected through main steam regulating valve to the boiler, and the low pressure heat exchanger is connected to the steam turbine, and the steam turbine is connected to the one end of condenser, and the low pressure heat exchanger is connected through the condensing pump to the other end, and boiler water supply equipment is connected to the other end of low pressure heat exchanger, and this system specifically includes: The composite energy storage subsystem is used for realizing the targeted participation of different types of batteries in different types of frequency modulation instruction requirements; The condensate throttling frequency modulation response subsystem is used for participating in auxiliary regulation when the composite energy storage subsystem cannot meet the frequency modulation response requirement of the power grid; the frequency modulation response subsystem is used for controlling the composite energy storage subsystem, the condensate throttling frequency modulation response subsystem, the boiler overshoot control subsystem and the main steam modulation door of the steam turbine to participate in frequency modulation response according to the received frequency modulation instruction and the actual output of the unit; The boiler overshoot control subsystem is connected with the adjusting valve between the boiler and the water supply equipment and between the boiler and the coal supply equipment, and is used for setting overshoot on the basis of the load instruction and adjusting the amount of water and coal entering the boiler whe