Ejection-type heat pump waste steam recycling heating mode and system based on complete thermoelectricity decoupling

Abstract

The invention discloses an ejection-type heat pump waste system recycling heating mode and system based on complete thermoelectricity decoupling, and belongs to the technical field of thermoelectricity combined production and centralized heating. A multistage ejection-type decoupling device is arranged aiming at related thermoelectricity problems of thermal power plants, a high-pressure driving steam inlet of a gas distribution ejector is connected with a new steam pipe, a low-pressure steam inlet is connected with a high-pressure cylinder exhaust re-cooling pipe, a medium-pressure exhaust steam outlet is connected with a boiler reheater inlet, and a re-heating pipe is provided with an external supply steam extraction opening; a steam supply ejector adopts high-pressure re-heated steam forejecting medium-pressure cylinder exhaust steam to obtain intermediate-stage pressure; an injection-type heat pump adopts high-pressure steam for recycling waste heat of low-pressure cylinder waste steam for heating. According to the control principle, the outer supply steam extraction flow of the re-heating pipe is equal to the sum of the driving steam amount plus / minus the warm water amount ofthe gas distribution ejector; high-pressure cylinder gas inlet amount and the low-pressure cylinder gas inlet amount are close to equal-proportion change; the steam supply ejector and the ejection-type heat pump are both adjusted according to the thermal-side demands; the optimum ejection ratio of the ejector is adjusted on this basis, and then complete thermoelectricity decoupling with stepless adjustment is achieved.

Description

technical field [0001] The invention relates to an injection heat pump waste steam recovery heating supply method and system based on complete thermoelectric decoupling, and belongs to the technical field of combined heat and power generation and waste heat recovery heating supply. Background technique [0002] In the context of current industrial development and structural adjustment, China's power production is currently in a severe surplus situation, and a large number of wind power, photovoltaics, etc. have been abandoned, resulting in the need for large-scale thermal power generation units to participate in peak regulation. However, due to the inherent characteristics of heat and electricity involved in the cogeneration system, it usually adopts the operation mode of setting power by heat or heat by electricity. Therefore, the National Energy Administration has issued a number of policy measures to promote thermal power decoupling and deep regulation Peak, flexible tran...

AI Technical Summary

Problems solved by technology

A complete thermoelectric decoupling solution must solve the following six basic problems: one is the overheating of the reheater caused by the overheating of the boiler and the unbalanced flow of reheated steam; the other is the thrust balance of the turbogenerator rotor; the third is safety The problem of stable operation; the fourth is the problem of operating economy; the fifth is how to achieve a large-scale problem; the sixth is the problem of saving investment

[0004] According to the above analysis, the existing thermoelectric decoupling schemes and their main problems are summarized as follows: heat storage schemes and electric boiler schemes occupy a large area and have a large investment scale, and cannot be fully and deeply decoupled; zero-effort transformation of low-pressure cylinders, including optical axis schemes , and the scheme of directly reducing or closing the steam intake of the low-pressure cylinder, and introducing a small amount of cooling steam to cool the final stage and the exhaust port, has little effect on increasing the heat supply; the problem of the joint steam distribution scheme of high and low bypass is that When the load rate of power generation is low, the recent pressure of the reheater is greatly reduced due to the large reduction of the steam intake of the turbine, so that the volume flow rate is greatly increased, and the flow capacity and heat transfer of the reheater are greatly reduced, and the smoke temperature of the reheater is difficult to be effective reduce the temperature of the reheater and subsequent heating surfaces, and cause damage; cylinder drilling and steam extraction, low-vacuum circulating water heating, etc. cannot effectively reduce the load rate of power generation; direct drilling and extraction of main steam, or high-pressure cylinder Drilling holes in the cold section of the reheater at the steam outlet (cold re) to extract steam, or drilling holes in the hot section (hot re) at the outlet of the reheater to extract steam can greatly reduce the load rate of power generation, but the amount of steam extraction is relatively large There must be a series of safety problems such as the overheating of the reheater and the overrun of the axial thrust of the steam turbine.

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