JPH065122B2 - Steam generator used for steam heat transfer means - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention guides saturated steam generated by a steam generator to a heat radiating section using a steam pipe, and gives latent heat to a surrounding fluid in the heat radiating section to generate heat. After discharging, the condensed condensate is temporarily stored, then the heating of the steam generator is stopped and the inside of the steam generator is made into a vacuum state. The present invention relates to a steam generator used in a steam-type transfer means for returning heat inside and transferring heat by repeating this.

・ Prior art and its problems Conventional steam generators are designed to continuously generate steam while supplying water so that the boiler liquid level is kept roughly constant, but the generated steam is radiated. To the target part, and the latent heat is applied to the target in the heat dissipation part to temporarily store the condensed liquid, and when the amount of liquid in the steam generator decreases, the generation of steam is stopped and it is generated inside the steam generator. Condensed liquid once stored in the heat radiation part by vacuum is returned to the steam generator, and after the liquid is filled, steam is repeatedly generated to transfer heat energy to the destination by vapor pressure,
Next, the amount of liquid in the steam generator increases / decreases in the steam generator used for the method of causing condensate to flow back into the steam generator by the vacuum generated in the steam generator (hereinafter referred to as the intermittent vacuum return liquid method). As a result, the heat transfer area where the combustion gas flow and the liquid come into contact with each other changes, which is a phenomenon that is not found in ordinary boilers.

As the steam generator used in the intermittent vacuum liquid returning method, a kettle type as shown in FIG. 1 can be easily conceived, but the thermal efficiency is as low as about 50% and there is a problem in terms of running cost. In order to increase the efficiency, as shown in FIG. 2, the space formed by the bottom surface 06 of the steam generator and the burner 04 is used as a combustion chamber 05, and the bottom surface 06 is made to act as a primary heat transfer surface for transferring heat from the flame. Further, while the combustion gas passes through the flue 010 provided at the center of the steam generator, the flue wall 07
When it is made to act as a secondary heat transfer surface, saturated vapor is generated with high thermal efficiency in the full liquid state, but the heat transfer area in contact with the liquid decreases with the decrease in the liquid amount, and the thermal efficiency decreases. Not only that, even if the fuel supply to the burner 04 is stopped, the steam generator can be easily heated because the steam generator itself is overheated at a downstream point of the combustion gas flow where contact heat transfer with the liquid is not performed. Is not cooled, the vacuum generation is delayed and the reflux time of the condensate is prolonged, which is also a problem from the standpoint of durability.

-Structure of the present invention is to eliminate the above-mentioned drawbacks, and the structure is to guide saturated steam generated by a steam generator to a heat radiating section using a steam pipe, and to radiate latent heat to surrounding fluid in this heat radiating section. The condensate that has been condensed by being supplied with heat is temporarily stored, and then the heating of the steam generator is stopped to form a vacuum state inside the steam generator. In the steam generator used in the steam-type heat transfer means for performing heat transfer by recirculating in the steam generator, a primary heat transfer section is formed immediately above the fuel heating section, and the primary heat transfer section is further formed. A secondary heat transfer part heated by combustion gas is formed on the above, and a liquid tank having a volume of about 10 times the volume of the primary heat transfer part is formed above the secondary heat transfer part. The liquid tank and the primary heat transfer part are connected by a descending pipe. Of.

With the above configuration, 1/3 to 1/2 of the combustion heat generated in the combustion heating section is absorbed by the primary heat transfer section, and the rest is absorbed by the secondary heat transfer section. The heat medium in the primary and secondary heat transfer sections that is heated by this heat absorption becomes saturated vapor and rises into the liquid tank, and further passes through the steam pipe to reach the heat dissipation section where heat is released and condensed. To do. The condensed heat medium is temporarily stored in the liquid storage, or is used as a part of hot water for hot water supply.
Then, when the heating is continued and the generation of saturated steam continues and the liquid level in the steam generator approaches the bottom of the liquid tank, the heating source is stopped. When the heating source is stopped, the heat vapor is contained in the primary and secondary heat transfer parts, but the saturated vapor remaining in the space inside the liquid tank is rapidly cooled through the vessel wall and condensed,
A vacuum is created in the liquid tank. The heat medium condensed earlier by this vacuum action is returned to the liquid tank. Heat transfer is performed by repeating this.

In the above configuration, the capacity ratio between the liquid tank and the primary and secondary heat transfer parts is preferably about 10: 1, but this ratio should not be too close in view of the size and the like.

Example FIG. 3 shows an example of the present invention. Code 1
Is a burner, 3 is a primary heat transfer section, 2 is a combustion chamber provided between the burner 1 and the primary heat transfer section 3, 9 is a flue passage through which combustion exhaust gas flows, and fins 8 are attached inside thereof. ing. A liquid tank 6 is connected to the primary heat transfer section 3 by a secondary heat transfer section 4 and a liquid descending pipe 5. 7 is a steam outlet.

Next, the operation of the above embodiment will be described.

Initially the interior of the steam generator is filled with liquid. Burner 1
When the fuel is supplied to the fuel, the fuel burns in the combustion chamber 1, and 1/3 to 1/2 of the combustion heat is transferred to the fluid in the primary heat transfer section 3. Combustion gas enters the flue 9 rising from the center of the combustion chamber 2, and rises due to buoyancy due to the difference in specific weight from the surrounding atmosphere. A fin 8 is attached to a portion of the flue 9 that constitutes the secondary heat transfer section 4, and 1/2 to 2/3 of the heat energy of the combustion gas held at the flue inlet is secondarily transferred. Heat part 4
Tell the fluid inside.

As long as the liquid is in the liquid tank 6, the liquid descends through the descending pipe 5 in the liquid phase, a part of which is vaporized in the primary heat transfer part to change to steam, and further heated in the secondary heat transfer part. The volume ratio (void ratio) of the phase is increased to rise in the secondary heat transfer section toward the liquid tank 6. The fluid circulation occurs based on the specific weight difference between the fluid in the descending pipe 5 and the secondary heat transfer section 4, and the height h and the void fraction of the fluid in the secondary heat transfer tube 4 cause Circulating power is determined. That is, when h is large, the weight difference between the fluid inside the liquid descending pipe 5 and the secondary heat transfer portion 4 increases, and the circulation force increases, and when the combustion amount of the burner 1 increases, the evaporation of the fluid is promoted. The void rate increases and the circulation power increases.

The upward flow in the secondary heat transfer part where the proportion of steam has increased is the liquid tank 6
After being separated into gas and liquid, the steam is transferred from the steam outlet 7 to a heat radiating section connected by a steam conduit (not shown) at a vapor pressure and given by latent heat of condensation, and then temporarily stored in a condensed liquid reservoir (not shown).

The capacity ratio between the liquid tank 6 and the primary heat transfer section 3 is designed to be about 10: 1, and the inner wall of the liquid tank 6 in contact with the flue 9 holds a liquid film by the fluid flowing at high speed, so that the body is overheated. It is possible to stably generate saturated vapor until almost all of the liquid in the liquid tank 6 is vaporized and discharged without being discharged.

When the burner 1 is stopped when the liquid in the liquid tank 6 of the steam generator has evaporated, the steam generation stops, the chamber wall cools and a vacuum is generated inside, and the operation is temporarily accumulated in the condensate reservoir. The liquid flows back through the steam conduit in the steam generator. If the burner 1 is ignited after the liquid tank 6 is filled with the liquid, steam generation is restarted. In this way, steam generation, transportation,
Heat energy is transferred to the destination in the form of steam by repeating a series of operations including heat dissipation, liquid storage, vacuum generation, and reflux.

In this embodiment, the liquid tank and the heat transfer section are separated, and since the fluid is circulated between them, the body of the steam generator is not overheated, and the total liquid amount of the steam generator is It became possible to vaporize and discharge up to about 90%, and improved the thermal efficiency.

FIG. 5 shows a structure in which the main constituent parts of the first embodiment are changed so that they can be individually separated. Reference numeral 11 is a burner, 12 is a combustion chamber, 13 is a primary heat transfer section having fins attached to the periphery thereof, and 14 is a secondary heat transfer section having vertical fins 18 attached to the periphery thereof. Is installed between the outlet of the tank and the upper part of the liquid tank 16. Reference numeral 15 is a descending pipe that connects the liquid tank 16 and the primary heat transfer section 13,
A vapor outlet 17 is provided at the top of the liquid tank 16. Reference numeral 19 is a flue provided so that the combustion gas passing through the primary heat transfer section is discharged to the outside through the secondary heat transfer section.

The operation of the second embodiment is the same as the operation of the first embodiment, and is caused by the evaporation of a part of the fluid in the primary heat transfer section and the increase in the void rate of the fluid in the secondary heat transfer section. The vertical pipe 14 that acts as the liquid descending pipe 15 and the secondary heat transfer section
The fluid is circulated based on the difference in weight of the internal fluid.

Further, in the third embodiment shown in FIG. 6, the primary heat transfer portion 23 is provided at the lowermost portion of the vertical pipe, and the burner is burned sideways in accordance with this.

In the second and third embodiments, the main constituent parts of the steam generator are arranged separately, so that the steam generator can be easily disassembled and cleaned.

-Effect of the present invention With the above-mentioned configuration of the present invention, the following effects can be obtained.

Since the heat transfer area where the combustion gas and the fluid in the steam generator contact each other can be increased, the thermal efficiency increases.

The heat transfer rate increases because the heat medium flows at high speed in the heat transfer section of the steam generator.

About 80% of the combustion heat is transferred to the fluid in the primary and secondary heat transfer parts, and the liquid film is held in the liquid tank due to the high-speed flow of the fluid, so the steam generator body is overheated. Therefore, saturated steam can be generated stably.

Since the liquid tank is cooled rapidly by stopping heating, the liquid tank is evacuated in a short time and the return time is shortened.

[Brief description of drawings]

FIG. 1 is a sectional view of a general steam generator, FIG. 2 is a sectional view of a steam generator having primary and secondary heat transfer surfaces, and FIG. 3 is an embodiment of the steam generator according to the present invention. 4 is a sectional view taken along the line AA, and FIGS. 5 and 6 are other embodiments. 1 ... Burner, 2 ... Combustion chamber, 3 ... Primary heat transfer part, 4 ...
… Secondary heat transfer part, 5 …… Descent pipe, 6 …… Liquid tank, 7 ……
Steam outlet, 8 ... Fins, 9 ... Flue.

Claims (1)

[Claims] 1. A saturated steam generated by a steam generator is guided to a heat radiating section by using a steam pipe, and the heat radiating section gives latent heat to a surrounding fluid to release heat, and the condensed condensate is temporarily stored. Liquid, and then the heating of the steam generator is stopped to form a vacuum inside the steam generator, the condensate is circulated back into the steam generator by utilizing this vacuum action, and heat transfer is performed by repeating this. In the steam generator used for steam type heat transfer means, a primary heat transfer section is formed directly above the combustion heating section, and a secondary heat transfer section is further heated above the primary heat transfer section by the combustion gas. And a liquid tank having a volume of about 10 times the volume of the primary heat transfer section is formed above the secondary heat transfer section, and a liquid drop pipe is provided between the liquid tank and the primary heat transfer section. A steam generator used for steam-type heat transfer means.