RU2469955C1 - Method of vacuum deaeration of make-up water of heating network at thermal power plant - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: method involves heating of source water to 35÷50°C in surface heater, which is then decarbonised, deaerated in vacuum; for that purpose, superheated delivery water is supplied to vacuum deaerator as heating medium, deaerated make-up water with temperature of 50÷60°C is removed from vacuum deaerator to storage tank and then to return pipeline of the heating network. As heating medium in surface heater of source water there used is deaerated make-up water that is supplied after the heater to return pipeline of heating network with temperature of 30÷45°C.

EFFECT: invention allows increasing the electric energy yield on heat consumption due to refusing to use as heating medium for heating of source water prior to vacuum deaeration of high potential steam.

1 dwg

Description

The invention relates to the field of power engineering and can be used at thermal power plants.

Analogs are known - methods for vacuum deaeration of heating system feed water at a thermal power plant, by which the source water is heated to 35 ÷ 50 ° C in a surface heater, then decarbonized, for this purpose air is supplied to the decarbonizer at the bottom of the column, and water is deaerated to the upper part under vacuum, for which superheated network water, deaerated make-up water with a temperature of 50 ÷ 60 ° C, and sometimes 60 ÷ 70 ° C are taken from the vacuum deaerator to the storage tank as a heating agent, and then this the temperature is fed into the return pipe of the heating system (see AS No. 1303562, article "Actual problems of using vacuum deaerators in open heating systems" in the journal "Heat Power Engineering", 1994, No. 8, p. 55, as well as AS No. 1267015). The analogue described in A.S. No. 1267015, adopted as a prototype.

The disadvantages of the analogue and prototype are the reduced cost-effectiveness of the vacuum deaeration method due to the mixing of make-up water deaerated under vacuum, which has a sufficiently high temperature, with return network water, which has a much lower temperature for most of the year. Due to the addition of make-up water, the temperature of the return network water rises, which leads to a decrease in the highly economical generation of electricity from the heat consumption of cogeneration turbines of a thermal power plant. In addition, to reduce the cost-effectiveness of the methods-analogues and prototype contributes to the use for heating the source water of significant quantities of steam, as a rule, a relatively high potential.

The technical result achieved by the present invention is to increase the efficiency of the method of vacuum deaeration of make-up water of the heating system at a thermal power station by supplying to the return network pipe of deaerated under-vacuum make-up water with the lowest possible temperature and a corresponding increase in the generation of electric energy for thermal consumption, as well as due to refusal to use high-steam steam as a heating medium for heating source water before vacuum deaeration potential.

To achieve this result, a method is proposed for vacuum deaeration of heating system feed water at a thermal power plant, in which the source water is heated to 35 ÷ 50 ° C in a surface heater, then deaerated under vacuum, for which superheated network water deaerated is supplied as a heating agent to the vacuum deaerator make-up water with a temperature of 50 ÷ 60 ° C is removed from the vacuum deaerator to the storage tank and then served in the return pipe of the heating system.

The peculiarity lies in the fact that deaerated make-up water is used as a heating medium in the surface source water heater, which, after the heater, is fed into the return pipe of the heating system with a temperature of 30 ÷ 45 ° C.

Next, we consider the information confirming the possibility of carrying out the invention with obtaining the desired technical result.

The drawing shows a fragment of a schematic diagram of a thermal power plant with a vacuum deaeration plant, explaining the method. The station contains a cogeneration turbine 1 with lower and upper steam extraction, which are connected to the lower 2 and upper 3 network heaters. The lower 2 and upper 3 network heaters are connected via a heated medium to the network water pipe 4. A raw water pipe 6 is connected to the water treatment plant 5 of the heating system 6. Water treatment plant 5 is connected by a chemically purified water pipeline to a deaerator 7, which is connected to the storage tank 8 of the deaerated make-up water. In the pipeline of deaerated make-up water between the storage tank 8 and the point of connection to the return pipe of the supply water 4 to the heater 2, a surface heater 9 is included, which is connected through the cooling medium to the raw water pipe 6 before the water treatment plant 5.

The method consists of the following operations.

The raw feed water is heated to a temperature of 35 ÷ 50 ° C in a surface heater 9 with deaerated make-up water before feeding the latter into the return network pipe 4. Next, the initial water is deaerated under vacuum, for which superheated network water is supplied as a heating agent to the vacuum deaerator. Deaerated make-up water with a temperature of 50 ÷ 60 ° C is removed from the vacuum deaerator to the storage tank, then it is used as a heating medium in a surface source water heater, due to which it is cooled to a temperature of 30 ÷ 45 ° C, after which it is fed to the return network pipeline 4 in front of the lower network heater 2. Due to the supply to the return pipe of deaerated make-up water cooled to 30 ÷ 45 ° C, the temperature of the return network water is lowered and the generation of electricity for heat consumption is increased on the turbine 1 nii.

Thus, an increase in the efficiency of the method of vacuum deaeration of makeup water of the heating system at a thermal power plant is achieved by supplying makeup water deaerated under vacuum with the lowest possible temperature and a corresponding increase in the generation of electric energy from heat consumption into the return network pipeline, as well as by refusing to use as a heating medium for heating the source water before vacuum deaeration of high potential steam.

Claims (1)

A method for vacuum deaeration of heating system feed water at a thermal power plant, comprising heating the source water to 35 ÷ 50 ° C in a surface heater, which is then deaerated under vacuum, for which superheated network water, deaerated make-up water with a temperature of 50 are supplied to the vacuum deaerator ÷ 60 ° C is removed from the vacuum deaerator to the storage tank and then fed to the return pipe of the heating network, characterized in that as the heating medium in the surface source water heater, de erirovannuyu makeup water, after which the preheater is fed into the heating system return pipe at a temperature of 45 ÷ 30 ° C.

Images