JPS60253772A - Liquid heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a furnace and smoke tube type liquid heating device, for example, a furnace and smoke tube type solution heating device used for heating an absorption solution (LiBr solution) in an absorption type water chiller/heater. Regarding equipment.

[Prior art]

An example of a furnace and smoke tube type liquid heating device used for heating an absorption solution in a conventional absorption type water chiller/heater will be explained with reference to FIGS. 7 and 8. FIG. 7 is a longitudinal sectional view of the heating device, and FIG. 8 is its I
- It is a cross-sectional view along the I line, and the code 1 in the figure is a furnace cylinder;
2 is a can body, 3 is a heat exchanger tube, 4 and 5 are grate, 6 is a rear continuous chamber (turn part), 7 is a front smoke amount, and 9 is a burner.

In the example shown in FIGS. 7 and 8, the combustion gas generated by the bar I9 first heats the solution around the furnace tube mainly by radiation heat transfer in the furnace tube 1, and then passes through the rear continuous chamber 1.
The liquid then enters the smoke tube group 3, where the surrounding solution is heated mainly by convection heat transfer. The temperature of the combustion gas is initially about 1500°C, but the temperature gradually decreases while exchanging heat with the solution, and in the rear chamber it reaches about 850°C.
The temperature in the front burning chamber 7 at the outlet of the smoke pipe group 3 is about 250°C.

Combustion gas passes through the front combustion chamber 7 and is discharged from the chimney 8 to the outside of the machine. The heating device shown in FIGS. 7 and 8 is of the so-called furnace tube and smoke tube type, and as shown in FIG. and smoke pipes, which have the following drawbacks:

(1) The length of the furnace tube and smoke pipe must be the same.

That is, when designing a furnace tube, the optimal furnace diameter and furnace length are determined from the flame length, cross section, product load, and combustion chamber load factor, taking into consideration the combustibility of the burner. On the other hand, for the λ smoke tube, the optimum value of the heat transfer tube diameter and heat transfer tube length can be determined from the heat transfer coefficient and allowable combustion gas passage pressure drop, but since there is a restriction on the required minimum length on the furnace cylinder side, the smoke tube is determined by the length of the furnace cylinder. It has to be matched, and depending on the amount of heat exchange in the flue, it may be longer than necessary.

This leads to an increase in the flow path pressure drop of the combustion gas, and to avoid this, there is waste such as increasing the diameter of the pipe (or increasing the number of smoke pipes. In other words, due to the structure, the furnace cylinder and smoke pipe are It is necessary to make the lengths the same, and the design is influenced by each other, making it impossible to create an optimal design.

(2) In the case of the above-mentioned conventional heating furnace, the heat transfer tube group and the furnace tube are attached to the same tube plate, but the furnace tube is heated to approximately 1000℃.
Since the combustion gas heating temperature of each heat exchanger tube group is approximately 500°C, it was necessary to take into account distortion due to the difference in thermal stress between the heat exchanger tube group and the furnace tube when designing the tube sheet. That is, for the reasons mentioned above, it was necessary to sufficiently ensure the thickness of the tube sheet and the shortest distance between the heat transfer tube group and the furnace cylinder, which is referred to as the pleating space. As a result, the amount of liquid held within the liquid heating device increases, resulting in an increase in price and weight.

(3) When using a heating device such as the one shown in Figure 7' to heat the absorption solution of an absorption type water chiller/heater, the heating fluid (combustion gas) is 'Form a flow path,
While lowering the temperature from about 1500℃ to about 250℃,
The fluid to be heated (absorbing solution) flows in at about 140°C, boils, separates the vapor, and flows out at about 160°C. However, the fluid to be heated does not form a fixed flow path inside the heating device, so Because it is in a stirred state like inside a rumbo, the temperature is almost uniform. That is, the state shown in A in FIG. 9 is considered to be close to that, and the temperature difference between the heated and heated fluids is Δt1 in state A and Δt' in state B, and the temperature difference in state B is larger than that in state A. Compared to state B, heat transfer is worse. For this reason, in the conventional example described above, there is room for improvement in the performance of the heater.

[Purpose of the invention]

An object of the present invention is to improve the drawbacks of the conventional furnace and smoke tube type liquid heating device.

[Structure of the invention]

The present invention provides a liquid heating device that accommodates a liquid to be heated between a tube plate that holds a furnace cylinder and heat transfer tubes, and a can body that surrounds the furnace cylinder and heat transfer tubes, in which the furnace cylinder and heat transfer tubes are separated from each other. It is a liquid heating device in which each can body is placed in a can body and exchanges heat with the liquid, and each can body is connected by a connecting pipe for heated combustion gas and the liquid to be heated, and the furnace cylinder and heat transfer tube group are optimized respectively. In addition to structurally solving the drawbacks of the prior art described in (2) above, the present invention enables a fixed flow of the liquid to be heated to be formed by inserting a partition plate into the can body. This improves heat transfer performance.

Next, the present invention will be explained in detail based on the drawings. Figure 1 shows an embodiment of the present invention, in which reference numeral 21 is a furnace cylinder, 22, 24 is a can body, 26 is a heat exchanger tube, and 25 is a combustion chamber. 26 is a gas communication passage, 26 is a heated liquid passage, 27 is a burner, 28
29 is the front baking chamber, 29 is the chimney, and 30 is the heated liquid inlet pipe.

In the liquid heating device shown in FIG. 1, the combustion furnace tube 21 and the heat transfer tube group 25 are housed in separate can bodies 22 and 24, respectively. Can bodies 22 and 24 are communicated by combustion gas and heated liquid passages 25 and 26. The combustion gas generated by the burner 27 first heats the liquid around the furnace tube in the furnace tube 21, and then passes through the combustion gas communication passage 25. , through the front smoke volume 28 and the chimney 29 to be discharged to the outside of the aircraft. On the other hand, the liquid to be heated is led into the can body 22 through the liquid inlet pipe 50, heated by the furnace tube, and then flows into the second can body 24 through the heated liquid passage 26 and heated by the heat transfer tube group. .

By adopting such a structure, the can body 22 housing the furnace tube 21 and the can body 24 housing the heat exchanger tube can be designed separately, and the furnace tube portion, furnace diameter, heat exchanger tube length, and tube body 24 can be designed separately. The diameter of the heat tubes and the arrangement of the heat transfer tube groups are optimal as they can be freely designed without being constrained by each other, compared to the conventional case where the furnace tube and the heat transfer tube group are housed in the same can body. This makes it possible to design In addition, when the conventional furnace tube and heat transfer tube group are housed in the same can body, the furnace tube 1 and the heat transfer tube group 3 are attached and fixed together to the same tube sheets 4 and 5, as shown in Fig. 7. be done.

During operation, the furnace tube is heated to approximately 1000℃ and the heat exchanger tube group is heated to approximately 550℃, so the amount of strain is different because the heating temperature of the combustion gas is different, but since they are fixed to the same tube sheet, the difference in strain is a relief. Without this, stress is generated and N is applied to the tube sheet. Therefore,
At the time of design, it is necessary to take this shadow 11# into consideration and provide the necessary thickness of the tube plate and the distance between the heat transfer tube group and the furnace cylinder.

However, in the present invention, there is no need to take such considerations at all, and the amount of liquid held in the machine and the weight of the machine are reduced, which is advantageous in terms of cost.

FIG. 2 is a diagram showing another embodiment of the present invention, in which the symbols 21 to 29 have the same meanings as in FIG. 34 indicates a partition plate, and 34 indicates a space at the inlet portion of the heated liquid in the can body 24.

In the embodiment shown in FIG. 2, the partition plate 33 is connected to the can body 2
The heated liquid is guided from the heated liquid inlet pipe 31 to the space 64 created in the can body 24 by the partition plate 53, where it exchanges heat with the downstream heated fluid. It is designed to be guided into the can body 22 by a rear connecting pipe 32, and thereafter heated in the same manner as in the apparatus shown in FIG. With this configuration, heat exchange is performed downstream of the heated liquid first, increasing the heat exchange efficiency, and as a result, the temperature of the exhaust combustion gas is reduced from approximately 250°C to approximately 200°C. It is possible to reduce the That is, heat exchange efficiency is improved by partially performing heat exchange in a countercurrent manner in order to promote heat transfer efficiency from combustion gas. Such a structure cannot be adopted with conventional heating devices and is round, and is only possible by housing the furnace cylinder portion and heat transfer tube S of the present invention in separate can bodies.

In addition, as shown in Fig. 3, a plurality of partition plates 63°56'...
is provided in the can body 24, and the liquid to be heated is introduced from the liquid to be heated inlet pipe 31 to the front smoke chamber side through the partition plate 63' of the space created in the can body 2'4 by the partition plate 33. It may be guided through the space in the direction indicated by the arrow to exchange heat with the downstream heating fluid, and then guided into the can body 22 through the communication pipe 62. In the embodiment shown in FIG. 3, a partition plate 66'' is provided on the passage 25 side of the can body 22, and the fluid to be heated is introduced from the outside of the partition plate into the can body 22 along the arrow. However, by doing so, it is possible to flow the fluid to be heated in opposition to the heating fluid, and the efficiency can be improved.

Still another embodiment will be explained based on FIG.

Each symbol in FIG. 4 has the same meaning as the symbol in FIG. 2. The characteristic of the apparatus shown in FIG. 4 is that the furnace tube is provided in the upper part and the heat exchanger tube group is provided in the lower part.

The liquid to be heated is first transferred from the pipe line 31 to the can body 22 containing the heat transfer tube.
Then, through the communication passage 26, it is introduced into the can body 24 in which the furnace cylinder 21 is housed.

On the other hand, the combustion gas passes through the furnace tube 21, the combustion gas passage 25, and the heat transfer tube group 23, passes through the front chamber 28, and exits to the chimney 29. With this configuration, the flow of the liquid to be heated and the flow of the combustion gas are opposed to each other, and the low-temperature liquid to be heated introduced into the can body 22 is heated by the heat transfer tube group and then transferred from the heat transfer tube group. Furthermore, since the furnace is heated by the high-temperature furnace cylinder, the heat exchange method is similar to a counterflow type, and the heat exchange efficiency is improved. This configuration is derived from the fact that the furnace cylinder part and the heat transfer part are made into side structures, and is unique to the present invention.

Furthermore, the embodiment shown in FIG. 5 is a combination of the previously described embodiments shown in FIGS. 2 and 4, and each reference numeral has the same meaning as that shown in FIG. . Lower can body 2
A partition plate 63 is provided at the inlet of the liquid to be heated, and the liquid to be heated is introduced from the pipe line 61 into the space 64 created in the can body 22 by the partition plate 33, and then flows into the can body 22. With this configuration, heat exchange is further performed in a countercurrent manner, and the heat exchange efficiency is further improved. In this example, two partition plates 33 are provided, but if necessary, one partition plate 33 or three or more partition plates 33 may be used.
Good too.

The structure of the partition plate is as shown in 33 in Fig. 6. It is stretched over the entire can body 1, and the holes are made loose so that the liquid to be heated can pass through the heat exchanger tube group, and the liquid can be removed from the can body through the gap. 2 may be allowed to flow.

[Brief explanation of the drawing]

1, 2, 3, 4, 5 and 6 are schematic cross-sectional views of the furnace and smoke tube type liquid heating device of the present invention for detailed explanation of the present invention, and FIG. 8 and 8 show a schematic cross-sectional view of a conventional furnace-fire-tube type fluid heating device, and FIG. 9 is a diagram for explaining the relationship between the temperature of the fluid to be heated and the temperature of the combustion gas in the conventional example. be. 1... Furnace barrel, 2... Can body, 6... Heat exchanger tube, 4.5
- Great, 6- Rear birth room, 7 Front continuous room,
9... Burner, 21... Furnace tube, 22.24... Can body, 23... Heat transfer tube, 25... Combustion gas communication passage,
26... Heated liquid passage, 27... Burner, 28...
- Front continuous chamber, 29... Chimney, 30.51... Heated liquid inlet pipe, 32. Connecting pipe, 53.53'. 53''...Partition plate, 34...Heated liquid inlet section agent Hirodo Nakamoto Bengami Shodo Yoshimine Katsura Figure 1 Figure 2 Figure 3 Figure 4 Figure 1 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1. In a liquid heating device that stores a liquid to be heated between a tube plate that holds a furnace cylinder and a heat transfer tube and a can body that surrounds the furnace cylinder and heat transfer tube, the furnace cylinder and the heat transfer tube A liquid heating device characterized in that the can bodies are housed in separate can bodies to exchange heat with the liquid, and the can bodies are connected by a communication pipe for heated combustion gas and the liquid to be heated. Z. The liquid according to claim 1, wherein the can body in which the heat transfer tubes are housed is divided by a partition plate, and the liquid to be heated is first introduced into the downstream side of the combustion gas in the divided can body. heating device. i. The liquid heating device according to claim 1, wherein a gap is provided between the partition plate and the heat transfer tube, and the gap is used as a communication path for the liquid to be heated before and after the partition plate. 4. The can body housing the heat transfer tubes was placed below the can body, and the furnace tube was placed above the can body, and the liquid to be heated was guided to the can body containing the heat transfer tubes at the bottom. 2. The liquid heating device according to claim 1, wherein the upper furnace tube is guided to the can body in which the upper furnace cylinder is housed, and the flow of the liquid to be heated and the flow of the combustion gas are opposed to each other.