Combined heat and power generation centralized heating system based on temperature counterpart gradient utilization

Abstract

The invention belongs to the technical field of energy sources, and particularly relates to a combined heat and power generation centralized heating system based on a temperature counterpart gradientutilization. According to the system, a circulating water is used for preheating a large-heat-net hot water, a water-supplying heater connected in series is used for heating the heat-supplying hot water of the large-heat-net step by step, and waste heat generated in the power generation process of a power plant is recycled; the hydrophobe and the exhaust steam condensate water of all the heaters inside the power plant are sequentially passed through four-stage series connection of water supply heaters, and then passed through a deaerator and a feed water pump, then the hydrophobe and the exhaust steam of all the heaters are returned to the boiler to be heated; the mode that a hot water absorption type heat pump and water-water heater are combined is used at the tail end to heat a secondarynet heat-supplying hot water in a hot water absorption type, so that the water return temperature of the-large-heat-net is reduced, and the temperature difference of the water supply and the water return of the large-heat-net is increased; and the water supply heaters are used for extracting the seam from a steam turbine and heating the heat-supplying hot water of the large-heat-net step by step,the water supply heaters are used for extracting the seam from the steam turbine and heating the hydrophobe and the exhaust steam condensate water in a step-by-step mode, so that the temperature counterpart gradient utilization of energy can be realized, the waste heat of the power plant is recycled as much as possible, and the heat efficiency of the system is improved.

Description

technical field [0001] The invention belongs to the field of energy technology, in particular to a centralized heat supply system for cogeneration of heat and power based on temperature counterpart cascade utilization. Background technique [0002] As a basic industry that has an overall and leading influence on the development of the national economy, the heating industry is closely related to people's lives. my country's urban central heating started in the 1950s. In recent years, my country's central heating business has developed rapidly, and the heat source of central heating is developing to large power plants. However, with the promotion of low-carbon economy and national energy conservation and emission reduction goals, the problems of low operating efficiency, excessive energy consumption and high heating cost of thermal power plants are particularly prominent. How to maximize energy saving and consumption reduction, improve comprehensive benefits, and reduce inve...

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Problems solved by technology

[0003] In the existing technology, the exhaust steam of the medium-pressure cylinder is often directly used to heat the return water of the large heating network or the exhaust steam of the medium-pressure cylinder is used to drive the heat pump to heat the return water of the large heating network. Complicated, high cost, did not optimize the effect of heat extraction

[0004] Chinese patent CN201710462791.3 discloses a thermal power unit waste heat cascade utilization heating system, which sequentially utilizes the exhaust heat of the low-pressure cylinder of the steam turbine, the heat of the exhaust steam of the low-pressure cylinder, and the heat of part of the exhaust steam of the medium-pressure cylinder, relying on the heat transfer effect of the heat exchanger to The return water of the heating network is heated in cascades, which increases the heatable return water of the heating network, improves the heating capacity of the unit, expands the heating area, and realizes the full use of heat in cascades; but in the cascade heating process of the heating system, the first The first-stage heating steam source comes from the exhaust steam of the medium-pressure cylinder and the partial extraction steam of the low-pressure cylinder, and the second-stage heating steam source comes from the exhaust steam of the medium-pressure cylinder, which is not a complete staged extraction steam, and most of them still use the exhaust steam of the medium-pressure cylinder Heat, did not fundamentally realize the cascade utilization of waste heat and optimize the system structure

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