Combined cycle heat supply and power peak regulation coupling system based on energy cascade utilization and operation method thereof

Abstract

The invention relates to a combined cycle heat supply and power peak regulation coupling system based on energy cascade utilization and an operation method thereof. The combined cycle heat supply andpower peak regulation coupling system comprises a gas turbine unit and a steam turbine unit; The gas turbine unit comprises a gas turbine compressor, a gas turbine combustion chamber, a gas turbine and a first generator; the steam turbine unit comprises a waste heat boiler, a steam turbine high-pressure cylinder, a steam turbine low-pressure cylinder, a second generator, a condenser, a condensatewater pump, a shaft seal heater, a deaerator, a temperature and pressure reducing device, acting equipment, power equipment, a pressure matcher, a steam heat accumulator, a heat grid heater, a hydrophobic heat exchanger, a heat grid circulating pump, a water storage tank and a circulating water pump; according to the invention, different steam temperature and pressure reducing modes are utilized to provide required heat sources for external heating, an integrated design of a steam extraction system is carried out based on the principle of the energy cascade utilization, and a steam heat storage system is coupled, so that the thermoelectric decoupling operation capability of a 9E type combined cycle unit is improved when the external heating demand is met.

Description

technical field [0001] The invention belongs to the technical field of improving the flexibility of thermal power units, and in particular relates to a combined cycle heating and power peak regulation coupling system based on energy cascade utilization and an operating method thereof. Background technique [0002] At present, my country's policies are gradually emphasizing the promotion of new energy sources and reducing the proportion of thermal power units, which makes the development of thermal power units face severe challenges. At present, in order to improve the comprehensive energy utilization efficiency of thermal power units and strive for more utilization hours of power generation, deeply excavating the heating capacity of thermal power units has attracted more and more attention from all walks of life. Gas-fired cogeneration is a form of energy utilization that produces heat and electricity at the same time. It uses high-grade heat for power generation and low-gra...

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Problems solved by technology

[0003] At present, the main problem faced by the central heating system of gas-fired cogeneration is that the heat-to-power ratio is low. The heat-to-power ratio generated by conventional gas-fired cogeneration combinations has certain limitations. The smaller it is, taking a 100,000 kW unit as an example, its heat-to-electricity ratio is about 0.7

Especially in the face of the current severe situation of deep peak regulation of thermal power, the units often operate under low load conditions. At this time, the external heating capacity of the units is lower, which has a serious impact on the safety of heating supply.

However, the existing technology such as the patent "A Combined Cycle Heat and Power Cogeneration System (Patent No. 201310401252.0)" is to use high exhaust steam extraction to reduce temperature and reduce pressure to supply heat to the outside. The technical defects are: (1) No consideration of energy The cascade utilization of direct temperature reduction and pressure reduction has a large loss of working capacity; (2) The need for deep peak regulation of thermal power is not considered. In order to meet the external heat supply, the unit needs to operate at a high load, and the peak regulation capacity of the unit is poor

Existing technologies such as the patented "gas-steam combined cycle heating system (Patent No. 201710534092.5)" use mid-exhaust steam extraction or low-pressure supplementary steam from waste heat boilers to provide the outside world with the steam required for heating and cooling. The low-pressure supplementary steam can be transported to the steam pipe of the adjacent machine. The characteristic of this technology is that it only considers the external heating demand, but does not consider the power peak-shaving demand of the unit. The peak shaving capacity of the excavator

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