JPH0639203Y2 - Boiler that reduces steaming time - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a steam boiler having a short steaming time and a high load bearing capacity.

[Conventional technology]

In the conventional steam boiler, the relationship among the amount of water held, the load bearing capacity, and the steaming time is as shown by the lines l ₁ and l ₂ in FIG.

In other words (when the heat transfer area of the boiler is constant), increasing the amount of retained water as A ₁ → B ₁ → C ₁ can improve the resistance to load fluctuations, that is, the load resistance as A ₂ → B ₂ → C _2. You can do it.

[Problems to be solved by the device]

However, when the load bearing capacity of this boiler is improved, the steaming time (the time required from the start of boiler operation until the generation of steam of a predetermined temperature and pressure) is A ₃ → B ₃ → C ₃ . It will be long. For example, in the case of a boiler in which a combustion chamber is composed of multiple pipe water pipes, if a large diameter water pipe is adopted, the number of components can be small and the amount of water held can be increased, but the steaming time becomes longer. , The product value will be low.

As described above, in the conventional boiler, the steaming time and the load bearing capacity are contradictory matters, and the boiler having the amount of water held is used in consideration of the balance between them. However, there is a problem that it is difficult to make a boiler having a short load and strong load bearing capacity.

An object of the present invention is to economically provide a boiler for shortening the steaming time in which the conventional problems are appropriately solved.

[Means for Solving the Problems]

According to the present invention, a large number of water pipes 2 are arranged in an annular shape, the upper end of each water pipe 2 is connected to an upper drum 3, and the lower end is connected to a lower drum 4 to form a combustion chamber 1 therein. In a multi-tube once-through boiler in which a water supply pipe 6 having a water supply pump 5 is provided in a drum 4, an inner pipe 7 is concentrically provided inside the water pipe 2 to divide the water pipe 2 into an inner chamber and an outer chamber. In addition, the upper portion of the inner pipe 7 is connected to the outer chamber of the water pipe 2 with the opening end as an open end, and the inner pipe 7 is provided with a communication mechanism for flowing boiler water from the outer chamber of the water pipe 2 to the inner chamber. is there.

[Action]

In the steam boiler of the present invention, the boiler water is supplied to the inner tube outer chamber prior to the inner tube inner chamber in the water tube to start the operation of the boiler. Since the apparent amount of water in the pipe is reduced to the amount equivalent to the outer chamber of the inner pipe because of the inner pipe, the boiler water in this outer chamber boils within a short time after the boiler operation starts, and the desired temperature, Steam of pressure is generated, the boiler water fills the inner tube inner chamber of the water tube after the start of the startup, and then this boiler water also boils and the entire boiler enters a steady operation state, and the load bearing capacity of the boiler is expected. The boiler operates as a small water holding type boiler at the start of operation, and thereafter acts as a large water holding type boiler, and the steaming time is short and the load bearing capacity is strong.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. In this multi-tube once-through boiler, a large number of water tubes 2 are annularly arranged around a combustion chamber 1. The upper ends of these water pipes are connected to the upper drum 3, and the lower ends thereof are connected to the lower drum 4. A water supply pump 5 is connected to the lower drum via a water supply pipe 6.

An inner pipe 7 is provided inside each of the water pipes 2 so as to be substantially concentric with the water pipe 2 to form the inner chamber, and an upper end opening of the inner pipe 7 is located above the water pipe 2. Further, a communication mechanism is formed between a lower end position inside each inner pipe 7 and a lower end position inside the lower drum 4 by a communication pipe 9 having a manual valve (or an automatic opening / closing valve) 8. The shape of the communication pipe 9 is as shown in FIG. 2, but FIG. 1 simply shows that the inner pipe 7 and the lower drum 4 communicate with each other in a flow sheet manner. That is, the second
As shown in the figure, the communication pipe 9 is composed of an annular portion and four branch portions radially connected to the annular portion and having a manual valve 8. In this way, while providing a plurality of branch parts,
The reason why the manual valve 8 is provided at each branch is to supply boiler water to each inner pipe 7 at a more uniform flow rate, but a structure in which one branch and one manual valve are provided may be used. it can.

In FIG. 1, H ₁ is the combustion start / stop water level of the burner 10, H ₂ is the water level of the feed pump ON, and H ₃ is the water level of the feed pump OFF.

Next, the operation mode of the once-through boiler will be described. After closing all the manual valves 8 in advance, the water supply pump 5 is operated to start supplying the boiler water to the lower drum 4.
In this case, the boiler water is supplied to the portion of the lower drum 4 and the water pipe 2 excluding the inner pipe 7, that is, the outer chamber, but when the water level reaches H ₁ , the burner 10 is ignited to start combustion of the boiler. Then, when the water level reaches H ₃ , water supply is stopped.
After that, the ON / OFF of the water supply pump 5 is controlled so that the water level of the outer portion of the inner pipe 7 of the water pipe 2 becomes H ₂ or more and H ₃ or less, and if the water level falls to H ₁ for some reason, Burner 10 stops burning. During this period, the inner chamber in the inner pipe 7 remains empty, so the amount of water held by the boiler is
The boiler water is significantly reduced compared to the conventional boiler which is not provided, and moreover, the boiler water held in the outer chamber of the inner pipe 2 is outside the inner pipe 7 and is directly heated via the boiler heat transfer surface. In a very short time, steam with a predetermined temperature and pressure starts to be generated.

Thus, after the steam from the boiler water outside the inner pipe 7 is supplied to a desired place for a predetermined time, each manual valve 8 is opened with a small opening, and the boiler water is started to be supplied to the inner pipe 7 at a small flow rate. 7 Continue to generate steam from outside. Then, when the water levels of the boiler water inside and outside the inner pipe 7 become substantially equal, the manual valve 8 is fully opened to increase the amount of water held by the boiler to a value during steady operation. 7 Steam is generated from the water held inside and outside the room.

It should be noted that all of the boiler operation operations can be performed by automatic control.

As described above, in this boiler, the time required to reach the water level H ₁ at the time of water supply is shortened by the volume of the inner pipe 7 as compared with the conventional boiler in which the inner pipe 7 is not provided. The water level at the time of stoppage and the heat transfer surface that receives heat from the combustion chamber are the same, but the amount of retained water is reduced by almost the volume of the inner pipe 7, and the temperature rise and pressure rise time of the generated steam are shortened accordingly. After all, the steaming time is shortened by the total time obtained when water is supplied and when water supply is stopped.

Another embodiment shown in FIG. 3 Next, the communication mechanism by opening a small hole ₇₁ in the lower end of the inner tube 7 into a plurality annular instead of the manual valve 8 is constructed. In this boiler, when the water level of the outer chamber of the inner pipe 7 in the water pipe 2 starts to increase due to the operation of the water supply pump 5, a constant water level difference occurs between the inner and outer chambers of the inner pipe 7. The water level difference, taking into account the boiler capacity and the like small holes 7 ₁ number is selected at design time by adjusting the area.

[Effect of device]

The steam boiler of the present invention divides the water pipe holding the can water into inner and outer parts by the inner pipe, supplies water to the outer chamber of the inner pipe to start the operation of the boiler, and then supplies water to the inner chamber of the inner pipe as well. Since it is configured to continue, the steam boiler that has a short steaming time and is robust against load fluctuations can be provided with a simple structure and at a low cost, and its operation and maintenance can be easily performed. is there.

[Brief description of drawings]

1 is a schematic vertical sectional view of an embodiment of the present invention, FIG. 2 is a bottom view thereof, FIG. 3 is a schematic vertical sectional view of another embodiment, and FIG. 4 is a graph showing characteristics of a conventional steam boiler. Is. 1 ... combustion chamber, 2 ... water pipe, 3 ... upper drum, 4 ... lower drum, 5 ... feed water pump, 6 ... water supply pipe, 7 ... inner tube, 7 ₁ ... small hole, 8 ... manual valve, 9 ... communication pipe, 10 ... Burner.

Claims (1)

[Scope of utility model registration request] 1. A large number of water pipes 2 are arranged in an annular shape, and each water pipe 2
The upper end of the upper drum 3 and the lower end of the lower drum 4
In a multi-tube once-through boiler in which a combustion chamber 1 is formed inside and a water supply pipe 6 with a water supply pump 5 is provided in the lower drum 4, an inner pipe 7 is concentrically provided inside the water pipe 2. The water pipe 2 is provided so as to divide the water pipe 2 into an inner chamber and an outer chamber, and the upper portion of the inner pipe 7 is connected to the outer chamber in the water pipe 2 as an open end. A boiler for shortening steaming time, which is provided with a communication mechanism for flowing boiler water into the inner chamber.