JPH0317443A - Heat exchanger - Google Patents

Abstract

PURPOSE:To make a uniform temperature at a thermal transmitting fin of a refrigerant passage member and expand a degree of prevention against a corrosion of combustion gas by a method wherein a thickness of a wall at the thermal transmitting fin of a refrigerant passage member formed with a passage is made thicker than a wall thickness of a wall opposite to the thermal transmitting fin. CONSTITUTION:A refrigerant passage member 15 connected thermally to an outer surface of a thermal transmitting wall partition member 11 is provided with several longitudinal passages 16. A wall 15a at the thermal transmitting fin 22A of the refrigerant passage forming passages 16 and an opposite wall 15b are provided to cause a wall thickness of the wall 15a to be larger than the wall 15b. Liquid refrigerant passed through a refrigerant inlet pipe 17 and entered an inlet header pipe 17 is divided to flow from a lower part of the refrigerant passage member 15 into several longitudinal passages 16. The thermal transmitting fins 22A and 22B transmit heat from the combustion gas within the hot gas passage 12 to the refrigerant passage member 15 thermally connected so as to sufficiently heat the refrigerant within the longitudinal passages 16 in the refrigerant passage member 15. The liquid refrigerant may start to its gasification and evaporation, resulting in forming two-phase state of gas and liquid. The generated air bubbles rise in the passage 16 and the combustion gas may transmit heat to the refrigerant with the hot gas passage 12.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a heat exchanger that heats a refrigerant with high-temperature gas such as combustion gas and is used in air-conditioning equipment. 2. Description of the Related Art A refrigerant heater as shown in FIG. 5 uses a refrigerant as the fluid to be heated, heats it with combustion gas, evaporates the liquid refrigerant, and transports the heat using latent heat to perform heating. In this system, a heat exchanger l for combustion gas and refrigerant and a radiator 2 are connected through a sealed pipe 3, and the refrigerant is forcibly circulated by a refrigerant conveying device 4 such as a refrigerant pump or a compressor installed in the sealed pipe 3. It is something. FIG. 6 shows a conventional example of the heat exchanger 1 (Japanese Unexamined Patent Publication No. 59-107167).
A pipe holding part 6 and a pipe 7 made of copper material through which the refrigerant flows are provided in the axial direction of the outer peripheral surface, and the combustion gas from the burner 8 flows horizontally and laterally into the cylindrical inner surface 9. This heats the refrigerant flowing through the horizontal pipe 7 that is sent by the refrigerant heater 4. However, this heating system requires external power to transport the refrigerant, and it is desired to reduce running costs during heating operation, including improving heat exchange efficiency.

In addition, as conventionally known techniques for this type of heat exchange device, Japanese Patent Laid-Open No. 63-105395 and Utility Model Laid-Open No. 63-1794
There is one shown in Publication No. 64.

These devices use refrigerant passage members that form many refrigerant passages in the vertical direction, but they also reduce the flow resistance of the refrigerant, increase the efficiency of heat exchange from the combustion gas of the burner to the refrigerant, and allow the refrigerant to flow from the heat transfer fins to the refrigerant. Smooth heat transfer to passage members, uniform temperature, and simplification and miniaturization of the heat exchange device structure! I! It has a problem. Problems to be Solved by the Invention In order to reduce running costs during heating operation, it is effective to eliminate external power for transporting refrigerant and transport heat without power. When performing refrigerant heating and heating using non-powered heat transfer, the natural circulation force of the gas refrigerant generated when the liquid refrigerant is heated is important. Conventionally, this type of heating device has a configuration such as a refrigerant heating heat exchanger 1 as shown in FIGS. 5 and 6, in which the refrigerant flows horizontally in a pipe 7 as one continuous passage. As a result, the gas fraction of the heated refrigerant in a two-phase gas-liquid state does not flow smoothly toward the outlet, resulting in stagnation of the refrigerant, resulting in localized abnormal overheating and large flow resistance of the refrigerant. Heat exchange efficiency is also low. In addition, since the combustion chamber and heat exchange section are integrated, the amount of heat exchanged is uneven depending on the combustion state, resulting in local overheating, which can lead to thermal decomposition of the refrigerant or abnormal temperature rises in the equipment, leading to issues with equipment reliability. .

Furthermore, in the conventional known techniques disclosed in Japanese Unexamined Patent Publication No. 63-105395 and Japanese Utility Model Application No. 63-179464, the heat transfer fin side of the refrigerant passage member forming a large number of passages is Heat is concentrated and received through heat transfer fins. For this reason, the thickness of the heat transfer fin side of the refrigerant passage member must be thicker than the side opposite the heat transfer fin to ensure smooth heat transfer, otherwise the temperature will likely become uneven in some areas and the refrigerant will not be heated efficiently. Furthermore, the thermal stress generated in the refrigerant passage members is large, which poses problems in terms of durability. The conventionally known technology has the above-mentioned problem because the thickness of the refrigerant passage member on the heat transfer fin side and the opposite side are the same. Also, the sulfur content in combustion gas. The fins and refrigerant passage members on the fin side are in a severe corrosive environment due to condensed water, etc. and high-temperature gas, and it is necessary to prevent fluorocarbon refrigerant from leaking into combustion gas and turning into harmful gas due to pitting corrosion, etc., and conventionally known techniques There are issues with these.

Furthermore, the known technology has problems in that the refrigerant passage members are provided on both sides of the combustion chamber, and the structure is complicated, such as using pipes to communicate them, and the heat capacity is large, and the cost is high.

The present invention is the same as the above conventional example! It solves the problem of $111 by uniformly heating the refrigerant, improving heat exchange efficiency, smoothing the flow of the refrigerant, uniform temperature distribution and safety of the heat exchange device, improving durability, simplifying the structure and making it more compact. . The purpose is to reduce costs. Means for Solving the Problems In order to solve the above problems, the heat exchange device of the present invention includes a refrigerant passage member having a plurality of vertical passages, and an inlet communicating with the passages and fixed to the refrigerant passage member. A heso goo tube and an outlet hesogoo tube, a heat transfer partition member closely fixed to one side of the refrigerant passage member, a heat transfer fin fixed to the heat transfer partition member, and a heat transfer fin side of the refrigerant passage member forming the passage. The thickness of the wall is thicker than the thickness of the wall on the opposite side from the heat transfer fins.

Effects of the present invention With the above-described structure, the temperature on the heat transfer fin side of the refrigerant passage member becomes uniform, and the margin against corrosion of combustion gas is increased. Since the refrigerant flows through one refrigerant passage member, the refrigerant is evenly divided. Furthermore, the basic structure is simplified with only one side of the refrigerant passage member. EXAMPLES Hereinafter, examples of the present invention will be explained based on the attached drawings. In FIGS. 1 to 4, 10 is a combustion chamber provided in communication with a burner 8 connected to a fuel supply device, U is a heat transfer partition member, and 12 is a high temperature gas passage, which is a heat transfer partition member. It has a combustion gas outlet 13 and an exhaust passage 14 which are provided in close contact with the combustion chamber 11 and communicated with the combustion chamber IO. A refrigerant passage member 15 is thermally connected to the outer surface of the heat transfer partition member 11, and is provided with a large number of vertical passages 16. This passage 16
There is a wall 15a on the side of the heat transfer fins 22A of the refrigerant passage member 15 forming the refrigerant passage member 15, and a wall 15b on the opposite side.The wall 15a is thicker than the wall 15b. 17 is an inlet header pipe provided at the lower end of the refrigerant passage member 15, and 18 is an outlet header pipe provided at the upper end of the refrigerant passage member 16, which connects the inlet pipe 19 and the outlet pipe 20, respectively, to the refrigerant circuit. At the other end of the inlet header pipe 17, an oil drain pipe 21 is bent downward. The inlet header pipe 17 and the outlet header pipe l8 are each communicated by a longitudinal passage l6. 22A and 22B are heat transfer fins provided so as to be in thermal contact with the inside of the heat transfer partition member 11, and are bent into a wave shape to form a large number of heat transfer fins. A heat insulating material 23 is provided to cover the entire remaining outer surface of the combustion chamber 10 that does not come in contact with the high temperature gas passage 12. The combustion gas outlet 13 has heat transfer fins 22A and 22B which are divided vertically by a large number of fins and have passages arranged above and below, and upper and lower passages 824 divided by the fins. 25 through the outer periphery of the heat transfer fins 22 and the exhaust passage 26. 27 and heat transfer fins 22
An exhaust pipe 28 communicating with the lower part of the exhaust pipe 28 is provided.

In the above horizontal command, the fuel supplied by the fuel supply device is combusted in the burner 8, and the high temperature gas generated in the combustion chamber 10 passes through the combustion gas outlet 13 between the heat transfer fins 22A and 22B of the high temperature gas passage 12. Passage 24. 25 and the exhaust passage 26. 27 and exhaust through an exhaust pipe 28.

The liquid refrigerant that has entered the inlet header pipe l7 through the refrigerant inlet pipe 17 is divided into a number of vertical passages l6 from the lower part of the refrigerant passage member 15, and the heat transfer fins 22A and 22B transfer the combustion gas in the hot gas passage 12. The heat is transferred to the thermally connected refrigerant passage member I5, and the refrigerant in the longitudinal passage l6 of the refrigerant passage member I5 is sufficiently heated. The heated liquid refrigerant then begins to vaporize and enters a gas-liquid two-phase state in which bubbles are generated in the liquid. The generated bubbles rise from below to above in the vertically provided passage 16 due to the buoyancy effect, and in particular, heat is transferred to the refrigerant in the high temperature gas passage 12 after the combustion gas exits the combustion gas outlet 13 from the combustion chamber IO. The uniform heating also reduces the flow resistance in the passage 16, thereby increasing the generation of bubbles, increasing the bubble rising force, increasing the natural circulation force, and bringing the liquid refrigerant that has not yet vaporized into the passage 16. A bubble pump action occurs that sends the refrigerant to the top. Further passage 1
Heat transfer fins 22A, 2 provided also at the upper and lower parts of 6
The entire heat transfer partition wall 1l other than 2B becomes a heat transfer area and absorbs heat more efficiently than the heated fluid flowing through the high temperature gas passage 12.
This further increases the natural circulation force by further heating the gas-liquid two-phase refrigerant inside. The refrigerant that has reached the upper end of the passage 1G flows into the outlet pipe 18 and flows out from the refrigerant outlet pipe 20 toward a radiator (not shown).

In this way, by heating from the bottom to the top of the vertical passage 16, not only the natural circulation is enhanced, but also the natural circulation force is further increased by intense heating by the heat transfer fins 22B at the bottom. Effects of the Invention As described above, the heat exchange device of the present invention comprises: a refrigerant passage member forming a large number of longitudinal passages; an artificial header pipe and an outlet header pipe that communicate with the passages and are fixed to the refrigerant passage member; The heat transfer partition member closely fixed to one side of the refrigerant passage member, the heat transfer fins fixed to the heat transfer partition member, and the thickness of the heat transfer fin side of the refrigerant passage member that formed the passage are opposite to that of the heat transfer fins. The following effects can be expected by making the plate thicker than the side plate.

(1) By making the thickness of the wall of the refrigerant passage member on the heat transfer fin side thicker than on the side opposite to the heat transfer fin, the wavy fins are fixed at regular intervals and tightly fixed to the heat transfer partition member, which causes a temperature difference. The temperature of the refrigerant passage member becomes uniform, and the refrigerant in the passage can be efficiently heated, and thermal stress is suppressed to prevent deformation. This prevents damage and improves safety against corrosion from combustion gas. It also prevents overheating and thermal decomposition of the refrigerant due to local temperature differences.

Furthermore, by bending the upper and lower parts of the refrigerant passage member toward the opposite side of the heat transfer fins, for example, even if the thickness of the outer wall decreases during processing at this bent part, the thickness of the wall before processing can be made thicker. Therefore, it is thicker than or the same thickness as the wall of the refrigerant passage member on the opposite side of the heat transfer fins. Therefore, there are no problems with pressure resistance or corrosion resistance at this bent portion.

Figure (2) By uniformly heating the refrigerant in the passage, the bubble pump effect is further enhanced, allowing for smooth flow of the refrigerant and non-motorized refrigerant transport, allowing heating with low running costs. (3) The refrigerant passage member is only on one side, allowing for significant simplification and miniaturization of the horizontal line.

[Brief explanation of drawings]

Claims (1)

[Claims] a refrigerant passage member forming a large number of vertical passages; an inlet header pipe and an outlet header pipe that communicate with the passages and are fixed to the refrigerant passage member; a heat transfer partition member closely fixed to one side of the refrigerant passage member; A heat exchange device in which the heat transfer fins fixed to the heat transfer partition member and the refrigerant passage member forming the passage are thicker on the side of the heat transfer fins than on the side opposite to the heat transfer fins.