SU1379467A1 - Method of protecting high-pressure preheters - Google Patents

Abstract

The invention makes it possible to increase the reliability of operation of high pressure heaters. When leaks appear in the heat exchange surfaces 8, one of the heaters is triggered by emergency protection, which is carried out in two stages. At the first stage, when the readings of one of the differential pressure gauges 12, installed between inlet 10 and feedwater output, increase sharply, and the reading of the control differential meter 13 remains unchanged, a pulse signal is sent to the actuator of the inlet valve 3. The latter disconnects the heater group and passes the nutrient water bypass bypass 9. In the second stage, when the protection in the first stage does not work, and the liquid level in the heaters' enclosures or in one of them continues to increase, when the second emergency level is reached are any of the signal pressure switches 14 connected to the positive pulse tube in the upper portion of the housing, and the minus at the bottom, to disable the preheater and the feed pump. 1 il.

Description

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ABOUT

The invention relates to the energy sector and can be used in high pressure heaters (LDPE) of the high pressure regeneration system of steam turbine power plants.

The purpose of the invention is to increase the reliability of LDPE.

The drawing shows a schematic diagram of a PVD protection system for implementing the proposed method.

The diagram shows a feed pump 1, connected by feedwater pipeline 2 to the inlet valve 3, behind which is installed a control throttle washer A, Generating a pressure drop at a nominal flow rate of not more than 1.5 MPa. Pipeline 2 feed water surface heaters are connected in series: the first is the heater 5, and the last is the heater 6, behind which the check valve 7 is installed

along the feed water heaters. The outlet from the last preheater 6, the feed water through the pipeline 2 through the check valve 7 is directed to the boiler or steam generator. When leaks appear in the heat exchange surfaces 8, one of the heaters is triggered by emergency protection, which is carried out in two stages.

In the first stage, when the readings of one of the differential pressure gauges 12 sharply increase, and the readings of the control differential pressure gauge 13 remain unchanged,

a pulse signal is supplied to the actuator of the inlet valve 3, which turns off the LDPE group and passes the feed water through the fast bypass 9. In the second stage, when the protection is

the first stage does not work, and the liquid level in the LDPE housings or in one of them continues to grow; when the second emergency level is reached, a signal is given from any of the differential

Valves 3 and 7 are designed to protect 25 meters 14 to shut off the LDPE and LDPE in case of liquid overflow from rupture of the heat exchange surfaces 8 and are interconnected by a pipeline - a fast bypass 9. Between inlet 10 and outlet 11 of feed water Differential gauges 12 are installed on each heater. A differential differential pressure gauge 13 is installed on the throttle washer D, indicating the pressure drop across the washer. On each, with a preheater, differential gauges 14 are installed, connected by a positive impulse tube in the upper part of the body and a negative one in the lower part.

body pump.

Claims (1)

Formula Eteni The method of protection of high pressure heaters in the event of a leak in the heat exchange surface, carried out in two stages, by measuring the liquid level in the heater bodies, disconnecting the feedwater and steam heaters in the first stage, and disconnecting the heaters and the feedwater pump to the specified limit value in the second stage, characterized in that, in order to increase the reliability of operation, the pressure drop across the throttle washer installed on the pipe is additionally measured as follows. Feed water pump 1 through line 2 through the inlet valve 3, the throttle washer 4 and the inlet water supply circuit for the feedwater supply in the sub-sub 10 is fed into the first preheater 5 along the feed water, the heat exchange surface 8 passes through the outlet body 11 through the outlet nozzle 11. Then the water through the pipeline 2 enters the following Compiled by M. Lazutov Editor N. Rogulich Tehred L. Oliynyk 50 The heaters, and the water pressure drop at the inlet and outlet of the preheater determine the difference between the measured differences and, if the latter is increased to a predetermined limit value, the first stage of protection is performed. Proofreader L. Pilipenko Order 958/34 Circulation 492 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 14 meters to turn off LDPE and power body pump. Formula Eteni The method of protection of high pressure heaters in the event of a leak in the heat exchange surface, carried out in two stages, by measuring the liquid level in the heater bodies, disconnecting the feedwater and steam heaters in the first stage, and disconnecting the heaters and the feedwater pump to the specified limit value in the second stage, characterized in that, in order to increase the reliability of operation, the pressure drop across the throttle washer installed on the pipe The heaters, and the water pressure drop at the inlet and outlet of the preheater determine the difference between the measured differences and, if the latter is increased to a predetermined limit value, the first stage of protection is performed. Proofreader L. Pilipenko Subscription