Steam extraction power generation and heat supply system of coupling steam extraction and condensing backpressure heat supply and operation method

Abstract

The invention discloses a steam extraction power generation and heat supply system of coupling steam extraction and condensing backpressure heat supply and an operation method. The system comprises asteam turbine medium pressure cylinder, a steam turbine low pressure cylinder, a steam condenser, a radial turbo, a cooling device, a steam-water heat exchanger, a first water drain heat exchanger, afirst station heating network heater, a second water drain heat exchanger, a generator and various steam and water pipelines and valves connected with the steam turbine medium pressure cylinder, the steam turbine low pressure cylinder, the steam condenser, the radial turbo, the cooling device, the steam-water heat exchanger, the first water drain heat exchanger, the first station heating network heater, the second water drain heat exchanger and generator; a cooling steam pipeline is connected with the inlet pipe position of the steam turbine low pressure cylinder, and a cooling device and a regulating valve are arranged on the cooling steam pipeline; one part of steam extracted from the steam turbine medium pressure cylinder enters the first station heating network heater to supply heat, and the other part of the steam enters the radial turbo to apply work; drained water produced after heat exchange is performed on the steam through the steam-water heat exchanger and the first stationheating network heater enters into the two water drain heat exchangers to perform cascaded heating on part of heating network return water; and by changing the operation modes of the system in heatingseason and non-heating season, the high-efficiency operation of the system is realized. The system realizes cascaded heating of a heating network, and lowers irreversible losses in the heat exchangeprocess.

Description

technical field [0001] The invention belongs to the technical field of heat and power cogeneration and energy saving, and in particular relates to a heat supply system and an operation method for coupling condensate pumping back heat supply with steam extraction and power generation. Background technique [0002] At present, my country's energy structure is constantly being transformed and upgraded, the proportion of new energy is gradually increasing, and the proportion of traditional thermal power is decreasing year by year. In order to meet the grid's ability to absorb new energy, this requires increasing the flexibility of thermal power units and thermal and electrical decoupling capabilities. In the past two years, with the advancement of thermal power flexibility work by the National Energy Administration, more and more thermal power units have undergone different forms of flexibility technology transformation to achieve thermoelectric decoupling capabilities, such as o...

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Problems solved by technology

However, for thermal power units, the design heating extraction pressure is basically greater than 0.2MPa, while the required temperature of the heating network water at the beginning and end of heating is only about 80°C, and there is a large loss of available energy in the heat exchange between the two

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