CN110608432A - A steam reheating system for domestic waste incineration waste heat boiler using main steam heating - Google Patents

Abstract

The invention relates to a steam reheating system for improving energy utilization efficiency by improving steam parameters of a garbage incinerator, which comprises main components of a waste heat boiler, a superheater, a steam reheater, a steam-water separator, a high-pressure cylinder and a low-pressure cylinder of a steam turbine, a condenser, a deaerator, a feed pump and the like. The main steam of the boiler enters a high-pressure cylinder of the steam turbine and a steam reheater in two paths respectively. The main steam enters a steam-water separator after acting in a high-pressure cylinder of the steam turbine, the separated water enters a deaerator, the steam enters a steam reheater and exchanges heat with the other path of main steam, and the reheated superheated steam is introduced into a low-pressure cylinder of the steam turbine to act. The system not only improves the energy utilization efficiency of the waste incinerator, but also avoids the corrosion of a steam reheating pipeline, and improves the equipment stability and the economic benefit of the waste incineration plant.

Description

A steam reheating system for domestic waste incineration waste heat boiler using main steam heating

technical field

The invention relates to a high-steam parameter domestic waste incineration power generation system, which is a system in which steam exhausted from a high-pressure cylinder of a steam turbine is separated from steam and water, heated by main steam in a steam reheater, and then enters a low-pressure cylinder of a steam turbine to perform work, thereby improving waste incineration. Improve the energy utilization efficiency of the furnace, and at the same time reduce the hazards of high-temperature corrosion of waste incinerators with high steam parameters.

Background technique

Domestic waste incineration can make urban domestic waste harmless, reduce its volume, and turn it into a resource. It is the best solution to the problem of garbage siege, so it is widely used. In my country, domestic waste treatment subsidies and electricity sales are important sources of income for waste incineration plants. As the industry becomes more and more market-oriented, government subsidies for waste treatment are getting less and less, and waste incinerators are increasingly relying on Therefore, improving power generation efficiency is the primary task of many waste incinerators.

Domestic waste incinerators usually use main steam with parameters of 400°C and 4MPa to generate electricity, but this steam parameter limits the energy utilization efficiency of waste incinerators. The power generation efficiency of waste incinerators using the above parameters is generally 23%. In order to improve the power generation efficiency of waste incinerators, in recent years, more and more waste incineration plants have increased the heat exchange ratio of superheaters in boilers to increase steam parameters to 450-485°C and increase steam pressure to improve power generation efficiency. However, limited by objective conditions such as high-temperature corrosion of boilers and dryness requirements of turbine end blades, if the traditional method is continued, the steam parameters cannot be further improved. Therefore, steam reheating can be adopted, without increasing the steam temperature Improve the overall thermal efficiency of the incineration plant.

Contents of the invention

In order to further improve the power generation efficiency of the waste incinerator, the present invention comprehensively adopts the high and low pressure cylinders of the steam turbine, the steam-water separation of the reheated steam, the intermediate reheating of the steam outside the furnace, and the heating of the main steam to improve the energy utilization efficiency of the waste incineration rate. Reduces high temperature corrosion of boilers and dryness limitation of last stage blades of steam turbines.

The technical solution adopted by the present invention to solve the technical problem is: a domestic waste incineration waste heat boiler steam reheating system heated by main steam. The main steam of the boiler enters the high-pressure cylinder of the steam turbine and the steam reheater respectively in two ways. The main steam enters the steam-water separator after doing work in the high-pressure cylinder of the steam turbine, and the separated saturated water enters the deaerator, and the saturated steam enters the steam reheater to exchange heat with another main steam, and the reheated superheated steam enters the low-pressure steam turbine cylinder work.

Furthermore, in the waste heat boiler 1, the heat generated by waste incineration is absorbed by water through the heat exchanger; the saturated steam from the steam drum 2 absorbs more energy in the superheater 12 and becomes the main steam of the high-temperature and high-pressure system; the steam from the superheater 12 The main steam enters the steam turbine high-pressure cylinder 5 and the steam reheater 4 respectively in two ways; the main steam enters the steam-water separator 10 after the steam turbine high-pressure cylinder 5 does work; the steam-water separator 10 separates saturated water from saturated steam, and the saturated steam enters The steam reheater 4 exchanges heat with the main steam from the superheater 2, and after being heated to superheated steam, it enters the steam turbine low-pressure cylinder 6 to expand and generate power; the saturated water separated by the steam-water separator 10 enters the deaerator 9; the steam turbine low-pressure cylinder The exhaust steam of 6 enters the condenser 8 to condense; the saturated water obtained by the condenser 8 then enters the steam drum 2 through the deaerator 9, the feed water pump 11, the economizer 3, etc., and starts the next steam-water circulation process.

The beneficial effect of the present invention is that the steam reheating technology is used to improve the energy utilization efficiency of the waste incinerator; it avoids placing the reheater tube bundle with poor heat exchange effect in the waste heat boiler flue with high temperature corrosion hazards, reducing The pipe corrosion of the steam reheating system has been reduced, and the equipment stability and economic benefits of the waste incineration plant have been increased; device) only provides main steam, so this reheat system can be used in the main control, multi-turbine (2 and above) incineration power generation system.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of a steam reheating system of a domestic waste incineration waste heat boiler using main steam heating according to the present invention.

In the figure 1. Waste heat boiler, 2. Steam drum, 3. Economizer, 4. Steam reheater, 5. High pressure cylinder of steam turbine, 6. Low pressure cylinder of steam turbine, 7. Generator, 8. Condenser, 9. Deaerator, 10. Steam-water separator, 11. Feed water pump.

Detailed ways

The present invention is a steam intermediate reheating system that improves energy utilization efficiency by improving the steam parameters of a waste incinerator. This embodiment is implemented on the premise of the technical solution of the present invention, and provides detailed implementation methods and specific operations process, but the protection scope of the present invention is not limited to the following examples.

The system consists of waste heat boiler 1, steam drum 2, economizer 3, steam reheater 4, steam turbine high-pressure cylinder 5, steam turbine low-pressure cylinder 6, generator 7, condenser 8, deaerator 9, steam-water separator 10, Feedwater pump 11 and other major equipment components.

(1) In waste heat boiler 1, the heat generated by waste incineration is absorbed by water through a heat exchanger;

(2) The saturated steam from the steam drum 2 absorbs more energy in the superheater 12 and becomes the main steam of the high-temperature and high-pressure system;

(3) The main steam from the superheater 12 enters the steam turbine high-pressure cylinder 5 and the steam reheater 4 respectively in two ways;

(4) The main steam enters the steam-water separator 10 after the steam turbine high-pressure cylinder 5 does work;

(5) The steam-water separator 10 separates the saturated water from the saturated steam, wherein the saturated steam enters the steam reheater 4, exchanges heat with the main steam from the superheater 2, and enters the steam turbine low-pressure cylinder 6 after being heated to superheated steam to expand and generate power ;

(6) the saturated water obtained by steam-water separator 10 separation enters deaerator 9;

(7) The exhausted steam in the low-pressure cylinder 6 of the steam turbine enters the condenser 8 to condense;

(8) The saturated water obtained by the condenser 8 then enters the steam drum 2 through the deaerator 9, the feed water pump 11, the economizer 3, etc., and starts the next steam-water circulation process.

The present invention will be further described below in conjunction with embodiment.

Example 1

The water-cooled wall above the refractory pouring material in the first flue of waste heat boiler 1 and the water-cooled wall of the second flue are protected by Inconel625 surfacing welding. The temperature and pressure of the main steam from the superheater 12 are 485°C and 13MPa respectively. The main steam at 485°C and 13MPa in the device 12 decomposes the temperature and pressure of the steam at 195°C and 1.4MPa returned from the high-pressure cylinder 5 to 320°C and 1.4MPa to become superheated steam, and the superheated steam (320°C, 1.4MPa) enters the low-pressure cylinder 6 of the steam turbine to do work. In the condenser 8, the exhaust steam from the low-pressure cylinder 6 of the steam turbine is cooled to supersaturated water at 25°C and 0.003MPa. The supersaturated water passes through the deaerator 9, economizer 3, The steam drum 2 enters the next steam-water circulation process.

Claims (9)

1. A steam reheating system of a household garbage incineration waste heat boiler heated by main steam is characterized in that the main steam of the boiler enters a steam turbine high-pressure cylinder and a steam reheater respectively in two paths; the steam enters a steam-water separator after acting in a high-pressure cylinder of the steam turbine, the separated saturated water enters a deaerator, the saturated steam enters a steam reheater to exchange heat with the other path of main steam, and the reheated superheated steam enters a low-pressure cylinder of the steam turbine to act; the heat source of the steam reheater is the boiler main steam from the superheater.

2. The steam reheating system of the household garbage incineration waste heat boiler adopting main steam for heating as claimed in claim 1, characterized in that in the waste heat boiler (1), heat generated by garbage incineration is absorbed by water through a heat exchanger; saturated steam from the steam drum (2) absorbs more energy in the superheater (12) and becomes system main steam with high temperature and high pressure; main steam from the superheater (12) enters a high-pressure steam turbine cylinder (5) and a steam reheater (4) in two paths respectively; the main steam enters a steam-water separator (10) after acting in a steam turbine high-pressure cylinder (5); the steam-water separator (10) separates saturated water from saturated steam, wherein the saturated steam enters the steam reheater (4) to exchange heat with main steam from the superheater (2), and after the steam is heated to superheated steam, the steam enters the low-pressure cylinder (6) of the steam turbine to expand to work and generate power; saturated water obtained by the separation of the steam-water separator (10) enters a deaerator (9); the exhaust steam of the low-pressure cylinder (6) of the steam turbine enters a condenser (8) for condensation; saturated water obtained by the condenser (8) then enters the steam drum (2) through the deaerator (9), the water feed pump (11) and the economizer (3) to start the next steam-water circulation process.

3. The steam reheating system of the household garbage incineration waste heat boiler adopting main steam for heating as claimed in claim 2, characterized in that the steam reheater (4) is a shell-and-tube heater, the tube side of the main steam heat exchanger (4) from the superheater (12) is used as a heating medium, and the return steam from the outlet of the steam turbine high-pressure cylinder (5) is heated.

4. The steam reheating system of the household garbage incineration waste heat boiler adopting main steam for heating as claimed in claim 2, characterized in that a steam-water separator (10) is adopted to separate the two-phase components of steam and water discharged from the high-pressure cylinder (5) of the steam turbine.

5. The steam reheating system of the household garbage incineration waste heat boiler adopting main steam for heating as claimed in claim 2, characterized in that a high-pressure cylinder (5) and a low-pressure cylinder (6) of a steam turbine are adopted, and exhaust steam of the high-pressure cylinder (5) is heated to be used as inlet steam of the low-pressure cylinder (6).

6. The steam reheating system of a household garbage incineration waste heat boiler adopting main steam for heating as claimed in claim 2, wherein the pressure of reheat steam from the steam reheater is not lower than 1.4MPa, and the temperature is not lower than 320 ℃.

7. The steam reheating system of the household garbage incineration waste heat boiler adopting main steam for heating is characterized in that the Inconel625 overlaying welding protection is adopted for the upper portion of the first flue and the second flue of the waste heat boiler (1).

8. The steam reheating system of a household garbage incineration waste heat boiler adopting main steam for heating as claimed in claim 2, characterized in that the main steam pressure from the waste heat boiler (1) is not lower than 13MPa, and the temperature is not lower than 440 ℃.

9. The steam reheating system of the household garbage incineration waste heat boiler adopting the main steam for heating as claimed in claim 2, wherein at least 2 waste heat boilers are arranged in the system, the main steam is connected in parallel through a main pipe, and at least 2 steam turbine power generation systems are arranged in the system at the same time.