Heating and steam extraction heat supply system of absorption heat pump

Abstract

The invention relates to a heating and steam extraction heat supply system of an absorption heat pump. The heating and steam extraction heat supply system comprises an intermediate-pressure cylinder, a low-pressure cylinder, a condenser, the absorption heat pump, a peak heater, a drain pump, a fifth low-pressure heater, an electric butterfly valve, electric gate valves, an electric adjusting valve, a circulating water pump, a heat supply network water supply pipeline and a heat supply network water return pipeline. The heating and steam extraction heat supply system mainly aims at the heating and steam extraction heat supply renovation project of a subcritical 300MW-level steam turbine; and according to the fundamental principle of the heating and steam extraction heat supply system, exhausted steam of the intermediate-pressure cylinder of the steam turbine is utilized as a high-temperature heat source of the absorption heat pump, circulating water of the condenser is utilized as a low-temperature heat source of the absorption heat pump, heat supply network circulating water is heated, and then the heat supply network circulating water is supplied to a heat user after being further heated through the peak heater. In the heating period, the absorption heat pump keeps operating at full load to the greatest extent, and the adjusting requirement of heat supply load changes is met through adjustment of the peak heater. According to the heating and steam extraction heat supply system, the aims of achieving energy gradient utilization of the exhausted steam of the intermediate-pressure cylinder, recycling waste heat of exhausted steam of the low-pressure cylinder and improving the economical performance of a unit are achieved, and the good economical performance and operation flexibility are achieved.

Description

technical field [0001] The invention belongs to the technical field of energy saving of thermal power plants, and is directly applied to a subcritical 300MW steam turbine heating extraction and heat supply transformation project to realize cogeneration of heat and power and improve unit cycle efficiency. Background technique [0002] At present, the main domestic heating extraction and heat supply transformation scheme is to drill holes in the medium and low pressure connecting pipes of the steam turbine, and lead the exhaust steam of the medium pressure cylinder into the heating network heater to heat the circulating water of the heating network to achieve external heating. The transformation plan is simple to implement for steam turbines with a capacity of 200MW and below, and the initial investment is small. There are already a large number of mature cases in China. High (above 0.7Mpa, far greater than the steam pressure 0.2-0.3MPa required by the heating network heater t...

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Problems solved by technology

The transformation plan is simple to implement for steam turbines with a capacity of 200MW and below, and the initial investment is small. There are already a large number of mature cases in China. High (above 0.7Mpa, far greater than the steam pressure 0.2-0.3MPa required by the heating network heater to heat the circulating water of the heating network), the general practice of some power plants is to decompress it through the pressure reducing valve and then enter the heating network heater for heating The heating network circulates water to realize external heating, which wastes high-quality steam to a certain extent

In addition, in order to cool the exhaust steam of the low-pressure cylinder of the steam turbine, the condenser needs a large amount of circulating water to absorb the waste heat of the exhaust steam of the low-pressure cylinder, and then discharge the heat into the environment, which is a kind of thermal pollution to the environment

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