JPH0781522B2 - Boiler equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler device, and more particularly to a boiler device having a valve device that requires heat retention in a closed state in a system.

<Prior art> The bypass control valve used in the start-up bypass system of the boiler device operates at the time of starting and stopping the boiler device, but maintains a fully closed state during normal operation, and also reduces the boiler load suddenly. It is possible to operate at any time when there is an abnormality such as.

If such a control valve is not warmed sufficiently while maintaining the fully closed state, a high temperature fluid flows when it is opened rapidly and the valve is partially rapidly heated, which causes thermal stress. .

Generally, as a method of performing warming, a bypass system in which a small bypass valve and a pressure reducing orifice are connected in series is used, and this bypass system is connected from the inlet pipe of the control valve to the outlet pipe by bypassing the vicinity of the control valve, A small amount of high-temperature fluid was flown into the bypass system to indirectly keep the control valve warm.

FIG. 3 is a system diagram of a conventional boiler device provided with such a control valve. The boiler body 1 includes a economizer 2, a water wall 3, a cage wall 4, a steam separator 5, a primary superheater 6, and a secondary superheater 7.
The steam that is more mainly configured and that is generated in the boiler body 1 is sent to the high-pressure turbine 9 through the main steam pipe 8.

The steam discharged from the high-pressure turbine 9 is returned to the reheated air 50 through the low-temperature reheat steam pipe 11 to be heated, and is aerated to the reheat turbine 10 through the high-temperature reheat steam pipe 12. Turbine exhaust is condensed in a condenser 13, increased in pressure by a condensate pump 14, and then supplied to a economizer 2 through a low pressure feed water heater 15, a deaerator 16, a feed water pump 17, and a high pressure feed water heater 18. It

When the boiler device having such a configuration is started, the hot water separated by the steam separator 5 is circulated to the inlet of the economizer 2 by the circulation pump 19, and the excess hot water is collected from the control valve 35b to the condenser. It is sent to 13 and the water level of the steam separator 5 is controlled. Further, the bypass steam branched from the main steam pipe 8 is sent to the condenser 13 from the control valve 35a for turbine bypass.

A front stop valve 34a is provided on the upstream side of the control valve 35a.
A warming pipe 33a is connected by branching on the upstream side of 34a. The warming pipe 33a is arranged near the front stop valve 34a and the control valve 35a, bypasses them, and is connected to the outlet side pipe 36a of the control valve 35a. A warming source valve 32a is provided in the middle of the warming pipe 33a.

A front stop valve 34b is also provided on the upstream side of the control valve 35b, and the warming pipe 33b is branched off further upstream of the front stop valve 34b.
Are connected. This warming pipe 33b has a front stop valve 3
4b and the control valve 35b are arranged in proximity to bypass them, and are connected to the outlet side pipe 36b of the control valve 35b. A warming source valve 32b is provided in the middle of the warming pipe 33b.

The warming source valves 32a and 32b can be opened and closed automatically as solenoid valves or piston valves, and the front stop valve 34 can be used during normal operation of the boiler.
With a and 34b fully closed, the warming source valves 32a and 32b are opened, and high-temperature fluid is constantly allowed to flow through the warming pipes 33a and 33b.
Heat 34a, 34b and control valves 35a, 35b. When the boiler is started, the front stop valves 34a, 34b and the control valves 35a, 35b are fully opened,
The warming source valves 32a and 32b are closed. In the figure, 20 is a heater reducer, and 24 is an inlet pipe.

<Problems to be Solved by the Invention> In this conventional boiler device, as shown in FIG. 3, the outlet sides of the warming pipes 33a and 33b are both connected to the condenser 13 side, respectively, and are constantly fed during normal operation of the boiler. The warming high-temperature fluid for warming flows into the condenser 13 as it is to become water. Therefore, the amount of heat of the high-temperature fluid that has flowed for warming causes heat loss in the boiler device, which is extremely uneconomical.

Also, since the warming pipes 33a and 33b are provided with decompression orifices (not shown), the warming pipes
From the outlets of 33a, 33b, a high temperature fluid for warming is ejected toward the pipe walls of the outlet side pipes 36a, 36b. During normal operation of the boiler, the stop valves 34a, 34b and the control valves 35a, 35b are fully closed, and no fluid is flowing through the outlet side pipes 36a, 36b.Therefore, the high temperature fluid from the warming pipes 33a, 33b is directly In addition, there is a problem that the pipe walls of the outlet side pipes 36a and 36b collide with each other, and the pipe walls are thereby worn.

The object of the present invention is to eliminate such drawbacks of the prior art,
It is an object of the present invention to provide a boiler device which minimizes heat loss and reduces abrasion of a pipe wall due to injection of a warming high temperature fluid.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the present invention has a warming pipe having an inlet portion on the upstream side of a valve device that requires heat retention when closed and a warming source valve provided midway. Is disposed close to the valve device or in addition to the pipe on the downstream side of the valve device, and by flowing a high-temperature fluid through the warming pipe when the valve device is closed, the valve device is indirectly operated. It is intended for a boiler device that heats and keeps warm.

Further, the outlet side of the warming pipe is connected to the pipe connected to the inlet side of the heat exchanger and through which the fluid flows.

<Operation> As described above, in the present invention, since the outlet side of the warming pipe is connected to the pipe connected to the heat exchanger, the high temperature fluid such as steam or high temperature water discharged from the warming pipe is directly heat-exchanged. It can be used by being installed in a condenser, and it requires less heat loss than the conventional system that flows into a condenser.
It is economical.

Also, by connecting the outlet side of the warming pipe to the pipe through which the fluid is flowing, it acts as a cushioning material for the fluid ejected from the fluid warming pipe flowing through the pipe,
Wear holes on the pipe wall are suppressed, and the useful life of the pipe wall can be extended.

<Example> Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view showing a heat retaining structure of a control valve, and FIG. 2 is a system diagram of a boiler device according to an embodiment.

First, the heat retaining structure of the valve will be described with reference to FIG. 31 in the figure
Is an inlet pipe, 32 is a warming source valve, 33 is a warming pipe, 34 is a stop valve, 35 is a control valve, 36 is an outlet pipe, 37 is a support band, and 38 is a heat insulating material.

The warming pipe 33 has a valve body having a front stop valve 34 at its upstream end.
It is connected on the upstream side of the valve element (not shown) of 34, and is arranged in proximity to the valves 34, 35 and the outlet pipe 36 by using a plurality of support bands 37.

During normal operation of the boiler device, the front stop valve 34 and the control valve 35 are fully closed, the warming source valve 32 is opened, and the high temperature fluid flows through the warming pipe 33 little by little. At that time, the support band 37 functions as an effective heat transfer means and also serves as a heat insulating material.
Due to the heat retaining function of 38, the high temperature fluid flowing through the warming pipe 33 indirectly heats the valves 34 and 35 and the outlet pipe 36.

In the case of this embodiment, the warming pipe 33 is positioned parallel to the inlet pipe 31 and the outlet pipe 36. However, the warming pipe 33 may be wound around the inlet pipe 31 and the outlet pipe 36, or a fin may be attached to the warming pipe 33. May be attached.

As shown in FIG. 2, such a heat retaining structure is applied to the front stop valve 34a and the control valve 35a for the turbine bypass, and the front stop valve 34b and the control valve 35b for controlling the water level of the steam separator.

The outlet side of the warming pipe 33a to which the control valve 35a for turbine bypass is applied is connected to the low temperature reheat steam pipe 11 connected to the inlet side of the reheater 50 which is one of the heat exchangers. The steam flowing through the warming pipe 33a merges with the steam flowing through the low temperature reheat steam pipe 11 and is reheated.

On the other hand, the outlet side of the warming pipe 33b applied to the control valve 35b for controlling the water level of the steam separator is connected to the inlet pipe 24 connected to the inlet side of the secondary superheater 7, which is one of the heat exchangers. The hot water that is connected and flows into the warming pipe 33b joins the hot water flowing through the inlet pipe 24 and is heated.

<Effects of the Invention> As described above, the present invention connects the outlet side of the warming pipe to the pipe connected to the heat exchanger, so that high temperature fluid such as steam or high temperature water discharged from the warming pipe is It can be used as it is by introducing it to the heat exchanger, and it is economical because it has less heat loss than the conventional system that flows into the condenser, and the fluid flows through the outlet side of the warming pipe. By connecting it to the existing pipe, the fluid flowing through the pipe acts as a cushioning material for the fluid ejected from the warming pipe, wear of the pipe wall is suppressed, and the useful life of the pipe wall can be extended. It has features.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a heat retaining structure of a valve used in an embodiment of the present invention, FIG. 2 is a system diagram of a boiler device according to an embodiment of the present invention, and FIG. 3 is a system diagram of a conventional boiler device. Is. 1 …… Boiler body, 7 …… Secondary superheater, 11 …… Low temperature reheat steam pipe, 24 …… Inlet pipe, 31 …… Inlet pipe, 32a, 32b ……
Warming valve, 33a, 33b …… Warming piping, 34
a, 34b ... Front stop valve, 35a, 35b ... Control valve, 36 ... Outlet piping, 50 ... Reheater.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masao Sasaki, 6-9 Takara-cho, Kure-shi, Hiroshima Babkotsk Hitachi Co., Ltd., Kure Factory (56) References JP-B 40-704 (JP, B1) JP-B Sho 59 -3608 (JP, B2)

Claims (1)

[Claims] Claim: What is claimed is: 1. A warming pipe having an inlet portion upstream of a valve device which needs to be kept warm when closed, and a warming source valve provided in the middle of the valve device. Placed close to the pipe on the side, and by flowing a high-temperature fluid through the warming pipe when the valve device is closed, in a boiler device that indirectly heats and heats this valve device, on the inlet side of the heat exchanger. A boiler device, wherein an outlet side of the warming pipe is connected to a pipe which is connected and through which a fluid flows.