JPH037683Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvements in the heat transfer aspects of composite boilers used in ships.

The auxiliary boiler used on ships uses the waste heat contained in the exhaust gas of the ship's engine, and when there is insufficient heat in the exhaust gas due to changes in engine load or stoppage, reheating is performed using the combustion device attached to the auxiliary boiler. , a composite type that obtains the required amount of steam is common.

This composite type boiler is mainly known to have a structure with an intermediate water chamber as shown in FIG. 1, or a structure with a partition wall in a group of water tubes as shown in FIG. 2.

Among them, a composite boiler having a structure with an intermediate water chamber connects an upper header 1 and an intermediate header 13 with a large number of water tubes 14, and uses the water tube group as a heat transfer surface for engine exhaust gas. The header 13 and the lower header 2 are connected by a number of water pipes 15, and the water pipes are configured to function as a heat transfer surface for the combustion gas generated in the combustion chamber provided in the lower water chamber. Therefore, since a composite boiler with this structure includes an intermediate header, the structure is complicated and expensive, and the installation space is also large.

On the other hand, a composite boiler with a structure in which a group of water tubes has a partition wall connects the upper header 1 and the lower header 2 with a large number of water tubes 16, each gap between the water tubes is used as a gas passage, and a partition horizontally divides this gas passage. 2 at wall 17
The water tube group facing the upper gas passage functions as a heat transfer surface for engine exhaust gas, and the water tube group facing the lower gas passage functions as a heat transfer surface for combustion gas. Therefore, although a composite boiler with this structure has a simple structure and requires a small installation space, the gas passage between the water pipes can be divided into two by a partition wall.
Because of the structure, it is difficult to keep the space between the partition wall and the water pipe airtight to prevent gas leakage during manufacturing, and if the water pipe is damaged due to unforeseen circumstances and needs to be replaced. This partition wall has the drawback of being difficult to replace and requiring a long time to replace.

The present invention aims to solve the above-mentioned drawbacks by providing the following means: An annular upper header that functions as a steam chamber; A cylindrical lower header that functions as a water chamber; Or an inner water tube group that forms an annular water tube wall when indirectly connected by fins and functions as a heat transfer surface; The above upper and lower headers are connected to each other directly or indirectly by fins. forming a concentric annular water pipe wall on the outside of the inner water pipe group in the connected state;
an outer water tube group that also functions as a heat transfer surface; an exhaust gas passage that is located between the inner water tube group and the outer water tube group and communicates two openings extending over the entire length of the pipes provided in the outer water tube group; A group of intermediate water tubes that function as a heat transfer surface when a large number of them are arranged at arbitrary intervals in a communicating exhaust gas passage; A combustion chamber provided inside the inner water tube group; A group of intermediate water tubes installed in the upper header facing the combustion chamber. Combustion device; Flue connected to the lower header plate on the opposite side of the combustion chamber; Penetrates the lower header in the axial direction of the combustion chamber to communicate the combustion chamber and the flue, and functions as a heat transfer surface. The present invention provides a composite boiler consisting of the required number of smoke pipes;

This invention will be explained below with reference to the drawings. Figure 3
4 is a vertical cross-sectional view of one embodiment of the present invention, and FIG. 4 is a cross-sectional view taken at - in FIG. 3. In the figure, reference numeral 1 indicates an annular upper header that functions as a steam chamber, and 2 indicates a cylindrical lower header that functions as a water chamber.
2 denotes inner and outer water tube groups 3 and 4, and intermediate water tube group 8, which will be described later.
They are made to communicate with each other. Inner water tube group 3
The upper and lower pipe headers are connected to each other directly or indirectly through fins (not shown) to form a substantially annular water pipe wall, and function as a heat transfer surface. Similarly, the outer water tube group 4 also communicates with the upper and lower headers, is closely connected to each other, and is arranged concentrically outside the inner water tube group 3 to form a substantially annular water tube chamber, and is formed into a substantially annular water tube chamber. Functions as a surface. By removing a portion of the outer water tube group 4, openings 5 and 6 are provided over the entire length of the tube, and each opening is an annular exhaust gas passage formed between the inner and outer water tube groups 3 and 4. Communication is made at 7. The drawing shows a structure in which openings 5 and 6 are located on opposite sides of each other, and the exhaust gas is branched to both sides at the opening 5 and flows through the exhaust gas passage, then merges at the opening 6 and is discharged to the outside of the system. However, the invention is not limited to this, and the openings 5 and 6 are provided adjacent to each other, and a partition wall is provided between the openings 5 and 6, so that the exhaust gas flows in from the opening 5, circulates around the annular exhaust gas passage, and then passes through the opening. It is also possible to have a structure in which the gas is discharged from the section 6 to the outside of the system. The intermediate water pipe group 8 communicates the upper and lower headers, is arranged in large numbers at arbitrary intervals in the exhaust gas passage 7, and functions as a heat transfer surface. Reference numeral 9 in the figure is a combustion device installed inside the upper header that communicates with a combustion chamber 10, which will be described later, and is configured to operate when the steam signal is below a set value and to stop when it is above the set value. has been done.
The combustion chamber 10 is formed within an annular inner water tube group 3. Reference numeral 11 in the figure is a flue connected to the lower header plate on the opposite side of the combustion chamber, and guides combustion gas to the outside of the boiler system. The combustion chamber and the flue are communicated by flue pipe groups 12 which pass through the lower header in the axial direction of the combustion chamber and are provided at arbitrary intervals. That is, the combustion chamber 10 formed in the annularly formed inner water tube group 3, the above-mentioned combustion device 9, and the smoke tube group 12 are located substantially in a straight line. Next, the operation of the above structure will be explained based on the flow of combustion gas. When the boiler is started and the ship's engine is running, the engine exhaust gas and combustion gas from the combustion device are used until the steam pressure of the boiler reaches the set value.
Heating is performed to generate steam, and when the steam pressure reaches the set pressure, the combustion device is stopped and only the exhaust gas is heated and evaporated. When the steam pressure falls below a set value due to an increase in load or a decrease in the heat retained in the engine exhaust gas, the combustion device is activated and the exhaust gas and combustion gas are heated and evaporated again. When the ship's engine is stopped, the combustion device is operated under control using a steam pressure signal to heat and evaporate only the combustion gas.

At this time, engine exhaust gas flows in from the opening 5 of the outer water tube group 4. While passing through the exhaust gas passage, this exhaust gas exchanges heat with the inner and outer water tube groups 3 and 4 and the intermediate water tube group 8 to lower the exhaust gas temperature, and is discharged from the opening 6 to the outside of the boiler system. The water in each water pipe in contact with the exhaust gas is heated, turned into steam, and supplied to a load (not shown) from the upper header. When the combustion device is activated, combustion occurs in the combustion chamber. The combustion gas in the combustion chamber mainly performs radiant heat transfer to the inner water tube group 3 to lower its temperature and reach the smoke tube. The combustion gas that has reached the flue reaches the flue while further decreasing its temperature mainly due to convective heat transfer, and is discharged from the flue to the outside of the boiler system. Inner water tube group 3 due to combustion gas
The water heated in the flue section of the lower header becomes steam and is supplied to a load (not shown) from the upper header. Here, the flow of water (heated water) from the lower header 2 to the upper header is in the opposite direction to the flow of the combustion gas (both flow in opposite directions). The exchange efficiency is high, and the pressure loss is small because the combustion gases described above flow substantially in a straight line without being bent along the way.

The present invention is constructed as described above, and has a structure that does not have an intermediate water chamber or a partition wall as in the conventional case, and has a structure in which the entire length of the pipes of the intermediate water tube group is extended within the annular passage between the outer water tube group and the inner water tube group. They are installed at arbitrary intervals so that the exhaust gas can be used to effectively absorb heat, and the combustion gas that has passed through the inner water tube group and the center (combustion chamber) can be directed to actively heat the lower header. Since it is discharged to the outside through a smoke pipe, the efficiency of the boiler can be further increased. In particular, the flow of combustion gases described above flows from the combustion chamber toward the flue with almost no bending, so there is little pressure loss, and this flow is a counterflow in the opposite direction to the flow of water from the lower header to the upper header. Therefore, extremely high heat exchange efficiency can be obtained. Moreover, since the present invention has a simple structure as described above, it is easy to manufacture and can be made into a compact, high-pressure-resistant, low-cost composite boiler. Also, since there is no partition wall that crosses the water pipe group, the water pipes can be easily replaced in a short time.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional composite boiler.
FIG. 2 is a vertical cross-sectional view of another conventional composite boiler, and FIG. 3 is a vertical cross-sectional view of an embodiment of the present invention.
FIG. 4 is a cross-sectional view of FIG. 3. 1... Upper header, 2... Lower header, 3...
Inner water tube group, 4... Outer water tube group, 5... Opening,
6... Opening, 7... Exhaust gas passage, 8... Intermediate water pipe group, 9... Combustion device, 10... Combustion chamber, 11...
... Flue, 12 ... Flue pipe, 13 ... Intermediate pipe stopper, 1
4...Water pipe, 15...Water pipe, 16...Water pipe, 17
...Partition wall.

Claims (1)

[Scope of Claim for Utility Model Registration] The following means: Annular upper header 1 that functions as a steam chamber; Cylindrical lower header 2 that functions as a water chamber; An inner water tube group 3 that forms an annular water tube wall when indirectly connected and functions as a heat transfer surface; In this state, an outer water tube group 4 forms a concentric annular water tube wall outside the inner water tube group 3 and functions as a heat transfer surface; between the inner water tube group 3 and the outer water tube group 4; An exhaust gas passage 7 that communicates two openings 5 and 6 extending over the entire length of the pipes provided in the outer water tube group 4; A heat transfer surface in a state in which the upper and lower pipe headers are connected and a large number of them are arranged at arbitrary intervals in the exhaust gas passage 7. a combustion chamber 10 provided inside the inner water tube group 3; a combustion device 9 attached to the upper header facing the combustion chamber 10; a lower pipe on the opposite side from the combustion chamber A flue 11 connected to the header plate; a required number of flues 12 passing through the lower header in the axial direction of the combustion chamber to communicate the combustion chamber and the flue and functioning as a heat transfer surface; A characteristic composite boiler.