JP2009243727A - Blow tank drain cooling method and its system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein conventionally, high temperature drain from inside a boiler building of a thermoelectric power plant is collected in a blow tank and is cooled only by cooling water in a drain line from the blow tank to a drain tank, and control of the temperature of the drain flowing into the drain tank could not be accurately controlled since the amount of cooling water is controlled by the temperature immediately after a blow tank outlet, leading to an increase in the cooling water. <P>SOLUTION: In the blow tank drain cooling method and its system, a temperature decreasing unit 3 for decreasing the temperature of the drain by the cooling water 4 is provided in the drain line laid from the blow tank 1 for collecting the high temperature drain of various drains 2 installed in the boiler building of the thermoelectric power plant to the drain tank 5, the drain is cooled by air by a cooling device 6 using air flowing into the boiler building, and the cooling water amount of the temperature decreasing unit 3 is controlled by the drain temperature after being cooled. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and a system for reducing and cooling high-temperature wastewater while draining from a blow tank that collects high-temperature wastewater from various drains installed in a boiler building of a thermal power plant to a drainage tank.

Conventionally, high temperature drainage from steam pipe drains installed in boiler buildings of thermal power plants and high temperature drainage during blow due to boiler pressure drop are collected in a blow tank, and the collected high temperature drainage is discharged from the blow tank. The drain line leading to the water tank was cooled only by cooling water.
Moreover, the control of the inflow temperature of the waste water flowing into the drain tank is performed by controlling the amount of cooling water with a temperature adjustment valve that operates according to the temperature immediately after the blow tank outlet.

  Therefore, there is a possibility that the temperature of the wastewater flowing into the drainage tank cannot be accurately controlled, and there is a problem that leads to an increase in the amount of cooling water.

  Therefore, the present invention provides a temperature reducer that reduces the temperature by cooling water in the drain pipe from the blow tank that collects high-temperature drainage from various drains installed in the boiler building of the thermal power plant to the drainage tank. And a cooling system for blow tank drainage, which is provided with a cooling device that uses air flowing into the boiler building to cool the air, detects the drainage temperature after cooling, and controls the cooling water amount of the desuperheater, and its system Is to provide.

  The present invention also provides a blow tank drainage cooling method and system in the above blow tank drainage cooling method and system, wherein a cooling device is provided for cooling by using the inflow air due to the negative pressure of the boiler building. It is.

  The present invention also provides a blow tank drain cooling method and system in which an air inflow port is provided in a side wall of a boiler building in the blow tank drain cooling method and system.

  The present invention also provides a blow tank drain cooling method and system in which a cooling device is provided outside the boiler building in the above blow tank drain cooling method and system.

  According to the blow tank drainage cooling method and system according to the present invention, the cooling water is reduced by the cooling water from the blow tank that collects high-temperature drainage from various drains installed in the boiler building of the thermal power plant to the drain pipe that goes to the drainage tank. In addition to reducing the temperature by providing a temperature reducer, it also cools the air by providing a cooling device that uses the air flowing into the boiler building, detects the temperature of the drainage after cooling, and controls the amount of cooling water in the temperature reducer The high temperature wastewater from the blow tank to the drainage tank can be air-cooled by the cooling device using the air flowing into the boiler building, so that it can be cooled by an inexpensive and simple cooling device. Not only can the cooling rate of the cooler cooling water be lowered, but the amount of cooling water can be reduced and cooling by air cooling can be performed. By detecting the temperature of the waste water flowing into the drain tank after, by controlling the amount of cooling water desuperheater, there is an effect that can accurately and reliably drainage temperature cooling.

  Further, the present invention does not require a blower or the like by providing a cooling device for cooling using the inflow air due to the negative pressure of the boiler building in the blow tank drainage cooling method and system described above. Therefore, there is an effect that the cooling device can be configured inexpensively and reliably.

  Moreover, this invention provides an air inflow part in the side wall part of a boiler building by having the structure which provides an air inflow part in the side wall part of a boiler building in said blow tank waste water cooling method and its system. In addition, the cooling device can be provided at a position that does not take up a place along the side wall.

  Further, the present invention provides the cooling method and system for blow tank drainage as described above, wherein the cooling device is provided outside the boiler building, so that the cooling device does not get in the way inside the boiler building and the outside air is sufficiently discharged. There is an effect that can be used for cooling.

  The present invention will be described below with reference to the illustrated embodiments.

In the illustrated embodiment, reference numeral 1 denotes a blow tank, which is formed from various drains 2 such as a main steam pipe drain, a furnace burner section soot blow drain, a superheater section soot blow drain, and a main water pipe drain disposed in a boiler building of a thermal power plant. High temperature waste water is introduced. The high-temperature waste water in the blow tank 1 is introduced into the temperature reducer 3 through the drain pipe 11 having the on-off valve 21, is cooled by the cooling water 4, and is sent to the drain tank 5.
In the drainage cooling system for the blow tank 1 according to the present invention, the drainage pipes 12, 15, 16 extending from the temperature reducer 3 to the drainage tank 5 are each provided with a cooling device 6 that cools the wastewater by the inflow air flowing into the boiler building. However, it is provided through the water distribution pipes 13 and 14.
22, 23, and 24 are open / close valves provided in the drain lines 15, 13, and 14, respectively, by closing the open / close valve 22 in the drain line 15 and opening the open / close valves 23 and 24 in the drain lines 13 and 14. The waste water is introduced from the temperature reducer 3 to the cooling device 6 and then sent to the drain tank 5.
In the case of the present invention, a negative pressure is applied to the boiler building so that the air in the boiler building is not scattered outside, and the outside air is always provided to the side wall of the boiler building configured to flow into the boiler building. The cooling device 6 is provided adjacent to the vicinity of the air inlet portion, and the cooling pipe of the cooling device 6 is configured to be cooled by the incoming air.
The cooling pipe of the cooling device 6 may be provided at the building side or at the air inlet, but if it is provided outside, it will not interfere with the boiler building and will fully utilize the outside air. And can be cooled.
Reference numeral 7 denotes a waste water temperature detection unit, which is provided between the drain lines 14 and 16 between the cooling device 6 and the drain tank 5. In the embodiment, the drainage temperature detection unit 7 is provided in the drainage pipe 16 near the drainage tank 5, detects the temperature of the drainage flowing into the drainage tank 5 after cooling by air cooling of the cooling device 6, and the detection. By controlling the amount of the cooling water 4 of the temperature reducer 3 by the automatic control valve 8 based on the temperature, the temperature reduction state of the high temperature waste water by the temperature reducer 3 is controlled to reduce the use of the cooling water. The drainage temperature can be cooled accurately and efficiently.

Explanatory drawing which shows the principle of this invention system roughly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blow tank 2 Various drains 3 Reducer 4 Cooling water 5 Drain tank 6 Cooling device 7 Drain temperature detection part 8 Automatic control valve 11-16 Drain line 21-24 Open / close valve

Claims (8)

A temperature reducer is installed in the drainage pipe from the blow tank that collects high-temperature drainage from various drains installed in the boiler building of the thermal power plant to the drainage tank. A blow tank drainage cooling method in which a cooling device using inflow air is provided to cool the air, detect the drainage temperature after cooling, and control the amount of cooling water in the desuperheater. The blow tank drainage cooling method according to claim 1, further comprising a cooling device that cools by using inflow air due to negative pressure of the boiler building. The blow tank drainage cooling method according to claim 1 or 2, wherein an air inflow port portion is provided in a side wall portion of the boiler building. The blow tank drainage cooling method according to claim 1, 2, or 3, wherein the cooling device is provided outside the boiler building. A high-temperature wastewater from various drains installed in the boiler building of the thermal power plant is collected in a blow tank, and a temperature reducer is installed in the middle of the drainage pipe that drains it into the drainage tank. A blow tank drainage cooling system which is provided with a cooling device for cooling using air flowing into the boiler building, detects the drainage temperature after cooling toward the drainage tank, and controls the cooling water amount of the desuperheater. 6. The blow tank drain cooling system according to claim 5, further comprising a cooling device for cooling by using the inflow air due to the negative pressure of the boiler building. The blow tank drain cooling system according to claim 5 or 6, wherein the blow tank drain cooling system is provided with an air inlet portion on a side wall portion of the boiler building. The blow tank drain cooling system according to claim 5, 6 or 7, wherein the blow tank drain cooling system is provided with a cooling device provided outside the boiler building.

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