RU2469956C1 - 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 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. Source water is heated in two stages: at the first stage, the source water is heated up to 30÷35°C in surface heater of source water of the first stage with deaerated make-up water, which is supplied after the heater to return pipeline of heating network with temperature of 30÷45°C, and at the second stage, the heating up to 35÷50°C is performed in surface heater of the second stage with superheated delivery water, which is supplied after heater of the second stage to pipeline of deaerated make-up water before the first stage heater.

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.

The analogue is known - a method for preparing makeup water of a heating system, in 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 in the upper part, for whereupon superheated network water is supplied to the vacuum deaerator as a heating agent, deaerated make-up water with a temperature of 50 ÷ 60 ° C is removed from the vacuum deaerator to the storage tank, and then it is fed to the heat return pipe with the same temperature ty (see AS No. 1303562, article “Actual problems of using vacuum deaerators in open heat supply systems” in the journal “Heat Power Engineering”, 1994, No. 8, p. 55, and 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, usually of 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 a heating system at a thermal power station by supplying to the return network pipe of deaerated under vacuum a make-up water with the lowest possible temperature and a corresponding increase in the generation of electric energy for heat 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 water of a heating system in a thermal power plant, in which the source water is heated to 35 ÷ 50 ° C, then decarbonized, deaerated under vacuum, for which superheated network water, deaerated feed water is supplied as a heating agent to the vacuum deaerator 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 the source water is heated in two stages, at the first stage, the source water is heated to 30 ÷ 35 ° C in a surface source water heater of the first stage with deaerated make-up water, which, after the heater, is fed into the return network pipe of the heating system with a temperature of 30 ÷ 45 ° C, at the second stage, heating to 35 ÷ 50 ° C is carried out in a surface heater of the second stage with superheated network water, which, after the heater of the second stage, is sent to the pipeline of the deaerated make-up water in front of the first stage heater.

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, the raw water pipe 6 is connected to the water treatment plant 5 of the heating system 6. The water treatment plant 5 is connected to the chemically treated water pipeline with a deaerator 7, which is connected to the storage tank 8 of the deaerated make-up water. The surface water heater 6 includes surface heaters of the first stage 9 and second stage 10. The heater 9 is connected via a heating medium to the deaerated make-up water pipeline between the storage tank 8 and the connection point to the network water pipe 4 to the heater 2. The heater 10 is connected via a heating medium to the heated network water pipe after the network heater 3. The heater 10 is connected by a chilled network water pipe to a deaerated make-up water pipe between the storage tank 8 and the heater Telem 9.

The method consists of the following operations.

The source water is heated in two stages, at the first stage, the source water is heated to 30 ÷ 35 ° C in a surface source water heater of the first stage 9 with deaerated make-up water, which after the heater is fed to the return network pipe of the heating system in front of the lower network heater 2 with a temperature of 30 ÷ 45 ° C. At the second stage, the source water is heated to 35 ÷ 50 ° C in the surface heater of the second stage 10 with heated mains water, which, after the second stage heater 10, is sent to the deaerated make-up water pipe before the first stage heater 9. Thanks to the supply of cooled to 30 ÷ into the return pipe 45 ° C deaerated make-up water lowers the temperature of the return mains water and increases on the turbine 1 the generation of electricity for heat consumption. Thanks to the two-stage heating, the technologically necessary temperature of the source water is provided in all modes of the method implementation. Due to the supply of network water after the heater 10 to the deaerated make-up water pipeline, the necessary cooling of this water in the heater 9 is provided before returning to the network pipeline before the heater 2.

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 electrical 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 is 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 the source water is heated in two stages, and in the first stage, the source water they are heated to 30–35 ° C in a surface source water heater of the first stage with deaerated make-up water, which, after the heater, is fed into a return network pipe of a heating network with a temperature of 30–45 ° C, and in the second stage, heating to 35–50 ° C is carried out in a surface the second stage heater with superheated mains water, which, after the second stage heater, is sent to the deaerated make-up water pipe before the first stage heater.

Images