JP5455573B2 - Multi-tube boiler - Google Patents

Description

  The present invention relates to a multi-tube boiler that heats a water tube by surrounding the combustion chamber in an annular shape with a number of vertical water tubes and performing combustion in the combustion chamber.

  A boiler having a shape in which a combustion chamber is provided in the center, the periphery of the combustion chamber is annularly surrounded by a number of vertical water pipes, and the outside of the annular water pipe row is a combustion gas passage is known. In the boiler, a burner is provided at the upper part of the combustion chamber, a high-temperature combustion gas is generated by burning a flame in the combustion chamber, and the combustion gas is brought into contact with the surface of the water tube surrounding the combustion chamber so that Heat the can water. The combustion gas first heats the portion of the water pipe facing the combustion chamber, and then heats the water pipe from the side of the combustion gas passage. Each water pipe is placed at a distance from the adjacent water pipe, and the combustion gas generated in the central combustion chamber is sent to the combustion gas passage through the gap between each water pipe, and the combustion gas passes through the water pipe gap. Sometimes the water tube is heated. Water pipe gaps are provided around the entire circumference of the combustion chamber, and the combustion gas is distributed radially from the combustion chamber toward the water pipe gap to flow the water pipes uniformly without heating concentrating on specific water pipes. Can do.

  In this case, if there is variation in the size of the gap between the water pipes, the amount of combustion gas flowing for each gap is different. In the manufacturing process, the variation in the gap is made as small as possible, but the variation in the location of the water pipe also occurs due to the shrinkage of the water pipe due to heat input during welding. I couldn't lose it. If there is variation in the size of the gap, there will be water pipes that heat up due to a large amount of gas passing, and water pipes that will heat down because of a small amount of gas passing. When the amount varies, the amount of heat absorbed by the entire water pipe decreases.

  In the invention described in Japanese Patent Laid-Open No. 57-65501, a spacer made of a round bar or the like is provided in a part of a water pipe gap surrounding the combustion chamber. The purpose of providing the spacer here is to cover the outside of the upper half of the water pipe with a refractory material so that it is not included in the heat transfer area, but by properly installing the spacer in the water pipe gap, It is also possible to obtain an effect of uniforming. However, as described in Japanese Patent Application Laid-Open No. 57-65501, when installing a round bar spacer, the installation position may be shifted in the front-rear direction between the water pipes because the spacer is a round bar. As a result, there was a problem that the size of the water pipe gap changed.

JP-A-57-65501

  The problem to be solved by the present invention is to provide a multi-tube boiler capable of further increasing the amount of heat absorbed by the water pipe in a boiler having a structure in which the water pipe is arranged so as to surround the periphery of the combustion chamber.

According to the first aspect of the present invention, a combustion chamber is provided in the center, the periphery of the combustion chamber is annularly surrounded by a number of vertical water pipes, the outside of the annular water pipe row is set as a combustion gas passage, and adjacent in the annular water pipe row. By leaving a gap between each water pipe, the high-temperature combustion gas generated in the combustion chamber heats the portion of the water pipe facing the combustion chamber and then flows to the combustion gas passage through the water pipe gap. In a boiler configured to heat a water pipe also from the side of the water pipe, a ring-shaped spacer is installed on the outer peripheral surface of the water pipe by passing the water pipe through the central space of a ring-shaped spacer having a predetermined thickness. and to so that determine the size of the water tubes gap an annular water pipe string by bite the spacer between the spacers provided at different heights of the water tube, the thickness of the spacer height position of the water pipe Depending characterized in that to adjust the width of the gap between water pipe by varied.

  The invention according to claim 2 is the above multi-tube boiler, wherein the ring-shaped spacer has a structure in which a part of the ring is notched, and the inner diameter of the ring is the same as the outer diameter of the water pipe or the outer diameter of the water pipe It is also characterized by being slightly smaller.

  Since the thinnest part of the water pipe gap is determined by the thickness of the ring-shaped spacer, the size of the gap does not change depending on the installation state of the spacer, and the size of each water pipe gap can be made uniform. Therefore, the heat absorption amount in the entire water pipe can be increased. The inner diameter of the ring-shaped spacer is the same as or slightly smaller than the outer diameter of the water pipe, and since the ring is partially cut away, If it is made to pass, the spacer can be held at a predetermined position simply by removing the force that opened the notch, and the workability during assembly can be improved. In addition, the size of the water pipe gap can be adjusted by changing the thickness of the spacer according to the spacer installation position, and the parameters related to the performance of the boiler by inducing the flow of combustion gas according to the size of the water pipe gap. It can also be said to adjust.

Cross-sectional view of a boiler implementing the present invention Longitudinal sectional view of a boiler implementing the present invention Explanatory drawing extracting the spacer installation part

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a boiler embodying the present invention, FIG. 2 is a longitudinal cross-sectional view of a boiler embodying the present invention, and FIG. 3 is an extracted spacer installation portion of the boiler embodying the present invention. It is explanatory drawing.

  The boiler is provided with a combustion chamber 1 in the center, and a combustion device 11 for generating a downward flame is attached to the upper portion of the combustion chamber 1. A large number of vertical water pipes 2 are arranged in an annular shape so as to surround the central combustion chamber 1, and water pipe gaps 3 are respectively provided between adjacent water pipes. A furnace tube 8 is installed outside the annular water tube row, and a space formed between the water tube 2 and the furnace tube 8 is used as a combustion gas passage 9. A combustion gas outlet 10 for discharging the combustion gas flowing in the combustion gas passage 9 to the outside of the boiler is provided at the lower portion of the furnace cylinder 8, and an exhaust cylinder 7 for discharging combustion exhaust gas is connected to the combustion gas outlet 10. doing.

  Below the half of the water pipe 2, a round bar 4 is provided to close the water pipe gap 3, and the water pipe gap 3 is provided only above the round bar 4. A ring-shaped spacer 5 is provided in the portion where the water pipe gap is opened. The spacer 5 has a predetermined thickness and is formed by cutting out a part of the ring, and the inner diameter of the ring is the same as or slightly smaller than the outer diameter of the water pipe 2. The spacers are a spacer 5A installed at a height position A near the top of the water pipe 2 shown in FIG. 2, and a spacer 5B installed at a height position B slightly above the upper end of the round bar 4. Installed in two stages. The spacer 5 is installed by skipping one water pipe arranged in a ring, and the water pipe in which the spacer 5 is installed and the water pipe in which the spacer 5 is not installed are alternately arranged.

  When the spacer 5 is installed in the water pipe 2, the inner diameter of the spacer 5 is increased by applying a force in the direction of opening the spacer notch 6, and the central space of the spacer 5 is passed through the water pipe in that state. When the force that has opened the spacer notch 6 is removed after that, the spacer 5 is tightened and the spacer 5 remains in the predetermined position. When the spacer 5 is welded to the water pipe 2 Even work becomes easier.

  The spacer 5 is a protrusion projecting from the surface of the water pipe 2 in the circumferential direction, and the water pipe provided with the spacer 5 can define a water pipe gap 3 between the right and left water pipes. What is necessary is just to provide in either. In other words, by alternately arranging water pipes provided with spacers 5 and water pipes not provided, water pipe gaps 3 corresponding to the thickness of spacer 5 can be provided between the water pipes, and the size of each water pipe gap 3 is made uniform. can do.

  When a flame is burned in the combustion chamber 1, the heat of the flame first heats the portion facing the combustion chamber 1 on the front side of the water pipe 2. Since the combustion chamber 1 and the combustion gas passage 9 outside the water tube row are connected by the water pipe gap 3, the combustion gas in the combustion chamber 1 goes to the combustion gas passage 9 through the water pipe gap 3. The water pipe gaps 3 are located between the water pipes around the circumference of the upper part of the combustion chamber, and the water pipe gaps are vertically long and narrow, so that the combustion gas becomes a large number of thin flows that spread radially. It flows through the gap 3 part. At this time, since the combustion gas flowing through the water pipe gap 3 flows on the surface of the water pipe, the water pipe is heated, and since the size of each water pipe gap 3 is made uniform by the spacer 5, the combustion gas is uniform between the water pipe gaps. And each water pipe can absorb an approximately equal amount of heat. If there is a deviation in the amount of combustion gas flowing radially from the combustion chamber 1 to the water pipe gap 3, the amount of heat absorbed by the water pipe will also be shifted, and in this case, the heat absorption amount in the entire water pipe will be reduced. End up. By averaging the combustion gas flow rate between the water pipe gaps and eliminating the variation in the amount of heat absorption in each water pipe, the amount of heat absorption in the entire water pipe can be increased. Thereafter, the combustion gas flows through the combustion gas passage 9 and heats the portion of the water pipe facing the combustion gas passage 9, and is discharged outside through the combustion gas outlet 10 and the exhaust pipe 7.

  Further, the water pipe gap 3 can be adjusted by the thickness of the spacer 5, and the thickness of the spacer 5A provided at the height position A is different from the thickness of the spacer 5B provided at the height position B. The size can be adjusted to induce combustion gases.

  For example, when the thickness of the spacer 5A is larger than the thickness of the spacer 5B, the width A of the water pipe gap at the height position A becomes larger than the width B of the water pipe gap at the height position B. When the width of the water pipe gap increases at the top, the combustion gas passing through the water pipe gap 3 will flow more in the water pipe gap at the top of the water pipe. The combustion gas that has passed through the water pipe gap 3 heats the portion of the water pipe 2 facing the combustion gas passage 9 while flowing downward through the combustion gas passage 9. Therefore, the heating amount of the water pipe can be increased by sending a large amount of combustion gas into the upper part of the combustion gas passage 9. When the gap at the height position A is increased by increasing the thickness of the spacer 5A, the amount of combustion gas flowing from the upper part in the combustion gas passage 9 increases, so the portion of the water pipe facing the combustion gas passage 9 The amount of heat absorption can be increased. However, widening the gap in the upper portion of the water pipe means that the water pipe gap near the combustion device 11 is widened, and the combustion gas before the completion of the combustion reaction is likely to be sent to the combustion gas passage 9. By passing through the water pipe gap before finishing the combustion reaction, if the amount of combustion gas cooled early by the water pipe increases, the problem that the amount of CO generated increases easily occurs.

  On the contrary, when the thickness of the spacer 5B is larger than the thickness of the spacer 5A, the width B of the water pipe gap at the height position B is increased, and the width A of the water pipe gap at the height position A is reduced. In this case, the combustion gas passing through the water pipe gap 3 flows more in the water pipe gap in the middle of the water pipe, and the amount of combustion gas flowing from the upper part in the combustion gas passage 9 is reduced. Less heat is absorbed. However, by separating the gap widening position from the combustion apparatus 11, the amount of combustion gas that passes through the water pipe gap and is cooled by the water pipe before the completion of the combustion reaction is reduced, and the amount of CO generated can be reduced. Thus, the flow of combustion gas can be induced by adjusting the thickness of the spacer 5, and the performance of the boiler such as the heat absorption amount and the CO generation amount can be adjusted.

DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 Water pipe 3 Water pipe gap 4 Round bar 5A A part spacer 5B B part spacer 6 Spacer notch part 7 Exhaust pipe 8 Furnace cylinder 9 Combustion gas passage 10 Combustion gas outlet 11 Combustion device

Claims (2)

A combustion chamber is provided in the center, and the combustion chamber is surrounded by a large number of vertical water pipes. The outside of the annular water pipe row is used as a combustion gas passage, and there is a gap between adjacent water pipes in the annular water pipe row. The high-temperature combustion gas generated in the combustion chamber heats the portion of the water pipe facing the combustion chamber, then flows through the water pipe gap to the combustion gas passage, and also heats the water pipe from the combustion gas passage side. In the boiler, the ring-shaped spacer is installed on the outer peripheral surface of the water pipe by passing it through the central space of the ring-shaped spacer having a predetermined thickness, and the spacer is put between adjacent water pipes. and to so that determine the size of the water tubes gap an annular water pipe string by a spacer provided at different heights of the water tube, the thickness of the spacer is changed in accordance with the height position of the water pipe Multitubular boiler, characterized in that to adjust the width of the tube between the gap.  2. The multi-tube boiler according to claim 1, wherein the ring-shaped spacer has a structure in which a part of the ring is cut out, and the inner diameter of the ring is the same as or slightly smaller than the outer diameter of the water pipe. A multi-tube boiler characterized by

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