JPH0730881B2 - Extraction method and extraction device for vacuum boiler - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vacuum boiler for generating hot water for hot water supply or heating, and more specifically, a can body having an internal pressure of atmospheric pressure or less, and a can body thereof. Heating means for heating the heat transfer medium enclosed in
A controller for adjusting the heating means so that the heat transfer liquid reaches the first set temperature, a heat exchanger for taking out heat for heating the fluid to be heated by the vapor in the can body, and a cover for the body in the can body. Extraction of a vacuum boiler provided with extraction means for discharging a condensable gas, and heat extraction control means for reversibly suppressing or stopping heat extraction by the heat exchanger in association with the operation of the extraction means. A method and an extraction device.

[Conventional technology]

In the vacuum boiler, by operating the extraction pump, to extract the non-condensable gas such as hydrogen and nitrogen, which is a factor that inhibits heat exchange in the heat exchanger, from the inside of the can to the outside, for example, , When extracting the heat while taking out the heat by the heat exchanger, the heat exchange in the heat exchanger, that is,
As a result of the steam being actively condensed on the heat exchanger surface as usual, the non-condensable gas is pulled to the heat exchanger side together with the steam, and the non-condensable gas is extracted by the extraction means (that is, the suction part by the extraction pump). Therefore, a large amount of non-condensable gas remains in the can even when the extraction pump is operated.

On the other hand, in the above vacuum boiler, which is provided with a heat extraction control means and is configured to stop or suppress the heat extraction by the heat exchanger at the time of bleeding, the condensation of steam on the surface of the heat exchanger at the time of bleeding is prevented. By suppressing or stopping the non-condensable gas to create a condition in which the non-condensable gas easily flows toward the extraction means, there is an advantage that the discharge of the non-condensable gas in the can can be facilitated and accelerated.

A technique conventionally known as a bleeding technique of a vacuum boiler having such an advantage is, as shown in Japanese Patent Laid-Open No. 192705/1982, as a heat extraction control means, to be heated to a heat exchanger during bleeding. A means for stopping or reducing the supply of fluid is provided, and at the time of bleeding by operating the bleeding pump, the heat extraction control means improves the bleeding performance only by facilitating and speeding the discharge of the condensable gas. This is the technology that I tried.

[Problems to be Solved by the Invention]

However, in the case of the above-mentioned conventional technique, since the air is extracted by simply suppressing or stopping the heat extraction in the heat exchanger by the heat extraction control means, the inside of the can is normally performing heat extraction by the heat exchanger. Therefore, air is extracted in a depressurized state at that time. Therefore, air is extracted in a state where the pressure difference between the inside of the can and the outside (atmosphere) is large, resulting in a large load on the extraction pump and providing heat extraction control means. In order to realize high-performance extraction by taking advantage of the ease and speed of non-condensable gas discharge, a large extraction capacity was required for the extraction pump. In other words, if the discharge capacity of the extraction pump is small, the discharge itself by the extraction pump takes time, although it is intended to facilitate and speed up the discharge of non-condensable gas by providing a heat extraction control means. It is not possible to achieve high performance of extraction air during the period.

An object of the present invention is to realize a high-performance bleed air that utilizes the ease and speed of non-condensable gas discharge by providing a heat extraction means while using a bleed air pump having a small discharge capacity. In point.

[Means for Solving the Problems]

The feature of the vacuum boiler bleeder according to the present invention is that the heat transfer medium is heated so as to reach the third set temperature which is higher than the first set temperature during the bleeding by the bleeding means.

Further, the vacuum boiler bleeding apparatus according to the present invention is characterized in that, when bleeding by the bleeding means, the heating means is operated so that the heat transfer liquid becomes a third set temperature which is higher than the first set temperature. A heating control means is provided.

[Action]

According to the bleeding method of the present invention, during bleeding by operating the bleeding means in a state in which heat extraction by the heat exchanger is suppressed or stopped, not only the heating action on the heat medium liquid is continued, but also the first set temperature. That is, since the heat transfer liquid is heated to the third preset temperature higher than the normal temperature when heat is taken out by the heat exchanger, the steam generation due to the heat transfer liquid heating during the extraction is more active than the normal time. The pressure inside the can can be increased by performing the above.

As a result, during bleeding, the pressure difference between the inside of the can and the outside can be reduced, and the load on the bleeding pump can be reduced.

Further, according to the bleeding device of the present invention, the heating control means, during the bleeding by operating the bleeding means in a state in which the heat extraction by the heat exchanger is suppressed or stopped, the heating action of the heating means on the heating medium liquid. Not only is it continued, but the heating means is operated to heat so that the heat transfer liquid becomes the first set temperature, that is, the third set temperature higher than the temperature at the normal time when heat is taken out by the heat exchanger. Since it is configured, similarly to the above method, during extraction, steam generation by heating the heat medium liquid can be performed more actively than in the normal time, and the internal pressure of the can can be increased.

As a result, during bleeding, the pressure difference between the inside of the can and the outside can be reduced, and the load on the bleeding pump can be reduced.

〔The invention's effect〕

Therefore, according to the present invention, even though a bleed pump having a small discharge capacity is used, as the discharge performance of the bleed pump, non-cohesive gas discharge by suppressing or stopping heat exchange in the heat exchanger during bleed We provide the extraction technology of the vacuum boiler that can achieve high performance corresponding to the simplification and speedup of heat generation, and can achieve high-performance extraction by making use of the ease and speed of discharge by providing the desired heat extraction control means. I can do it now.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to FIG.

The vacuum boiler has a pump body (1) having an internal pressure equal to or lower than atmospheric pressure and containing a heat transfer medium, a heating unit for heating the heat transfer medium, and a load (2). 3), a heat exchanger (4) for taking out heat for heating the water to be heated circulated through the heating medium vapor in the can body (1), a controller (5), and the can body ( 1) An extraction device for discharging the non-condensable gas in the outside to the outside.

The lower part of the can body (1) is formed in the liquid distillation section (1A), and the upper part thereof is formed in the reduced pressure steam chamber (1B).

The heating means includes a furnace (6) for heating the heat transfer medium inserted in the liquid distillation section (1A) of the can body (1), and a combustion furnace for heating the heat transfer medium (6). ) And a burner (7) with a blower (7a).

The heat exchanger (4) is arranged in the reduced pressure steam chamber (1B).

The controller (5) is basically an operation switch (8).
Is turned on, the burner (7) is burnt, and
After the pump (3) is operated, the heat transfer liquid is brought to the first set temperature by the setter (9) based on the temperature detected by the liquid temperature sensor (S ₁ ) for detecting the temperature of the heat transfer liquid. The temperature control is performed to adjust the opening of the fuel valve (10) provided in the fuel supply path to the burner (7).

The air extraction device includes an air extraction means, a heat extraction control means, and a heating control means.

The bleeding means is provided with a gas fraction (11) communicating with the depressurized vapor chamber (1B) of the can body (1) for retaining the non-condensable gas, and the non-condensable gas is externally supplied to the gas fraction (11) ( The air extraction path (12) for discharging to the atmosphere) is connected to the extraction air path (12),
The check valve (13) for allowing only one-way gas flow from the gas distillation (11) to the outside and the extraction pump (14) for discharging gas are provided with the check valve (13) on the gas distillation (11) side. And is provided with valve means and control means.

The extraction pump (14) is a diaphragm type general-purpose small vacuum pump.

The valve means includes the check valve (1) in the bleed passage (12).
Intermediate part (12) located between 3) and the bleed pump (14)
It is a means for communicating and blocking a) from the outside. Specifically, a branch pipe (15) for communicating it with the outside is connected to the intermediate portion (12a), and an opening / closing valve (16) using a solenoid valve is interposed in the branch pipe (15). There is.

The control means is a gas temperature sensor for detecting the temperature in the gas fraction (11) when the temperature detected by the liquid temperature sensor (S ₁ ) is equal to or higher than a second preset temperature lower than the first preset temperature ( When the operating condition is such that the difference between the temperature detected by S ₂ ) and the temperature detected by the liquid temperature sensor (S ₁ ) exceeds the first set value, the open / close valve (16) is opened and the extraction pump (1
4) actuated, then set time [bleed pump (14)
Is a sufficient time until it stops in a steady operating state, which is generally several seconds such as 5 seconds. ], The on-off valve (16) is closed, and the difference between the temperatures detected by the liquid temperature sensor (S ₁ ) and the gas temperature sensor (S ₂ ) is less than the second set value which is smaller than the first set value. When this occurs, the extraction pump (14) is stopped. That is, basically, the liquid temperature and gas distillation (1
By determining whether or not the non-condensable gas remains in the gas fraction (11) based on the temperature difference from the gas temperature in 1), and by controlling the start / stop of the extraction pump (14) based on that determination. , Automatic bleeding is performed, but after bleeding is started, the load on the bleeding pump (14) is eliminated by opening the open / close valve (16) for a set time and communicating the suction port of the bleeding pump (14) with the atmosphere. The start-up operation that enables the operation of the extraction pump (14) is automatically performed. This control means is incorporated in the controller (5).

The heat extraction control means stops the pump (3) under the above-mentioned operating conditions and when the temperature detected by the liquid temperature sensor (S ₁ ) is not less than the second preset temperature and not more than the first preset temperature. Is a means for reversibly stopping the heat extraction by the heat exchanger (4), and is incorporated in the controller (5).

The heating control means, when the operating conditions described above,
By operating the fuel valve (10) to the larger opening side,
The heating means is a means for heating the heat medium liquid so that the liquid temperature becomes a third set temperature which is higher than the first set temperature, and is incorporated in the controller (5).

The second set temperature is determined by the performance of the extraction pump (14), and the third set temperature is the maximum temperature that can be heated.

Incidentally, examples of the second set temperature and the third set temperature are 75 ° C. and 90 ° C., and the first set temperature is an intermediate temperature between them, for example, 85 ° C. In addition, the extraction pump (1
As an example of a real number of the temperature difference for operating 4), it is 10 ° C., and the temperature difference for stopping the extraction pump (14) is smaller than that, and it is preferably 0 ° C.

According to the configuration of the above embodiment, when the automatic extraction is started under the above-mentioned operating conditions, at the same time, the stop of the heat extraction in the heat exchanger (4) is started, and the heat exchanger (4) is started.
At this point, the condensation of steam in the heat exchanger started, the flow of steam to the heat exchanger (4) side disappeared, and the non-condensable gas easily flowed to the gas distillation (11). The heating rise is started, the internal pressure of the decompression steam chamber (1B) rises, the load on the extraction pump (14) is reduced, and the capacity of the extraction pump (14) increases. Therefore, bleeding can be performed efficiently.

[Another embodiment]

As shown in FIG. 2, the valve means is provided with a three-way valve (V) which can be switched between a state where the intermediate portion (12a) is inserted into the outside and a state where it is not communicated with the outside.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of essential parts showing another embodiment of the present invention. (1) …… can body, (4) …… heat exchanger.

Claims (2)

[Claims] 1. A can body (1) having an internal pressure equal to or lower than atmospheric pressure, heating means for heating a heat medium liquid enclosed in the can body (1), and the heat medium liquid having a first set temperature. A controller (5) for adjusting the heating means so that the heat exchanger (4) for taking out heat for heating the fluid to be heated by the vapor in the can body (1), and the can body ( 1) bleeding means for discharging the non-condensable gas in the inside, and in conjunction with the operation of the bleeding means,
In a vacuum boiler provided with heat extraction control means for reversibly suppressing or stopping heat extraction by the heat exchanger (4), a third boiler having a temperature higher than the first set temperature when the air is extracted by the air extracting means. A method for extracting air from a vacuum boiler that heats a heat transfer liquid to a set temperature. 2. A can body (1) having an internal pressure equal to or lower than atmospheric pressure, a heating means for heating the heat medium liquid enclosed in the can body (1), and the heat medium liquid having a first set temperature. A controller (5) for adjusting the heating means so that the heat exchanger (4) for taking out heat for heating the fluid to be heated by the vapor in the can body (1), and the can body ( 1) bleeding means for discharging the non-condensable gas in the inside, and in conjunction with the operation of the bleeding means,
In a vacuum boiler provided with heat extraction control means for reversibly suppressing or stopping heat extraction by the heat exchanger (4), a third boiler having a temperature higher than the first set temperature when the air is extracted by the air extracting means. A bleeder for a vacuum boiler provided with heating control means for operating the heating means so that the heat transfer liquid becomes a set temperature.