JPH0718596B2 - Heat exchanger - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger that heats a refrigerant with a high temperature gas such as combustion gas and uses the refrigerant in a heating and cooling device.

2. Description of the Related Art A refrigerant heating and heating device as shown in FIG. 5 is known as a device for heating by using a refrigerant as a fluid to be heated and heating by combustion gas to evaporate a liquid refrigerant to carry heat by latent heat for heating. ing. This refrigerant heating and heating apparatus connects a heat exchanger 1 for combustion gas and a refrigerant and a radiator 2 with a sealed pipe line 3 and forcibly circulates the refrigerant by a refrigerant carrier 4 provided in the sealed pipe line 3. is there. The heat exchanger 1 is shown in an enlarged manner in FIG. 6, in which a plurality of fins 6 are provided on the inner peripheral surface of a cylindrical body 5 extending in the horizontal direction, and a pipe holding portion 7 is provided on the outer peripheral surface of the cylindrical body 5 in the axial direction. The burner 9 is provided with a pipe 8 in which a refrigerant flows inside is embedded in the pipe holding portion 7.
The combustion gas from the inside is horizontally flown into the cylindrical body 5 to heat the refrigerant sent by the refrigerant carrier 4 and flowing in the pipe 8.

However, this heating system requires external power to carry the refrigerant, and it is desired to reduce the running cost during heating operation.

Therefore, in order to reduce the running cost during the heating operation, it is effective to remove the external power for carrying the refrigerant and carry the heat without power. When performing refrigerant heating and heating by non-powered heat transfer, the natural circulation force due to the buoyancy of the gas refrigerant generated by heating the liquid refrigerant is important. However, the conventional refrigerant heating and heating apparatus uses the heat exchanger 1 as shown in FIG. 6, and since the refrigerant flows in the pipe 8 extending in the horizontal direction, it is heated and is in a gas-liquid two-phase mixed state. The gas component of the refrigerant does not flow smoothly toward the outlet, causing stagnation of the refrigerant, causing local abnormal overheating, and because the combustion chamber and heat exchange part are integrated, the amount of heat exchange is uneven depending on the combustion state. Therefore, there are problems such as local overheating, thermal decomposition of the refrigerant, and abnormal temperature rise of the equipment.

The present invention solves such a problem, and it is possible to reduce the running cost by enabling non-powered conveyance, and to improve the reliability by preventing thermal decomposition of the refrigerant and abnormal temperature rise of the equipment. That is the purpose.

Means for Solving the Problems In order to solve this problem, the present invention provides a combustion chamber having one end side in communication with a burner connected to a fuel supply device, and a combustion chamber provided in communication with the other end side of the combustion chamber. A combustion gas outlet, a high temperature gas passage communicating with the combustion gas outlet, and a plurality of upper and lower passages provided in close contact with a heat transfer partition wall covering the high temperature gas passage in the high temperature gas passage and having a large number of passages in the vertical direction. A step heat transfer fin, a refrigerant passage member in close contact with the outer surface of the heat transfer partition wall, and a heat insulating material covering the inner surface of the combustion chamber,
The passage length of any one of the plurality of heat transfer fins is made longer than the passage length of the other heat transfer fins.

With this configuration, the natural circulation cycle of the refrigerant heating device heated by a burner or the like is transferred to the transfer partition wall of the high temperature gas passage through which the combustion gas ejected from the combustion gas outlet provided in communication with the combustion chamber of the heat insulating structure passes. By dividing with multiple heat transfer fins that are in close contact and making the passage length of one of the heat transfer fins longer than the passage length of the other heat transfer fin, the combustion gas can be made to flow uniformly on the heat transfer surface. The parts of the refrigerant passage member can be uniformly heated, the refrigerant can be circulated smoothly, and the non-powered heat transfer can be reliably carried out without locally overheating the refrigerant to prevent thermal decomposition of the refrigerant.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1 to FIG. 4, reference numeral 11 denotes a combustion chamber provided at one end thereof in communication with a burner 12 connected to a fuel supply device. The combustion chamber 11 is provided with a high temperature gas passage closely attached to a heat transfer partition wall 13. The other end of the member 14 communicates with the combustion gas outlet 15. In addition,
The hot gas passage member 14 has an exhaust pipe 16. Specifically, the hot gas passage member 14 is combined with the transmission partition wall 13 to form a hot gas passage. A refrigerant passage member 17 that is thermally connected is provided on the outer surface of the heat transfer partition wall 13, and the refrigerant passage member 17 is provided with a large number of passages 18 oriented in the vertical direction. An inlet header pipe is provided at the lower end of the refrigerant passage member 17.
19 is provided, and an outlet header tube 20 is provided at the upper end of the refrigerant passage member 17. An inlet pipe 21 is connected to one end of the inlet header pipe 19, an outlet pipe 22 is connected to one end of the outlet header pipe 20, and each is connected to the refrigerant circuit. An oil drain pipe 23 bent downward is provided at the other end of the inlet header pipe 19. Further, the inlet header pipe 19 and the outlet header pipe 20 communicate with each other through the vertical passage 18. Inside the hot gas passage, the combustion gas outlet 15 is provided so as to be in thermal contact with the inner surface of the heat transfer partition wall 13.
The heat transfer fins 24 and 25 are provided at positions sandwiching from above and below, and these are bent in a wavy shape. By the way, the combustion chamber
Reference numeral 11 is a cylinder, and a heat insulating material 26 is provided on the inner surface thereof. Further, the heat transfer fins 24, 25 are provided with a large number of passages 24a, which are vertically oriented in a state of being attached to the heat transfer partition wall 13.
An exhaust passage which forms the heat transfer fins 24, 25 and passes through the outer periphery of the heat transfer fins 24, 25 in a state where the heat transfer fins 24, 25 are covered with the high temperature gas passage member 14 and gathers at the lower center of the lower heat transfer fins 25. 27 are to be formed. The exhaust passage 27 communicates with the exhaust pipe 16. The length of the passage 25a of the heat transfer fin 25 is equal to that of the passage 2 of the heat transfer fin 24.
It is longer than the length of 4a.

In the above structure, the fuel supplied by the fuel supply device is burned by the burner 12, and the high temperature gas generated in the combustion chamber 11 passes through the combustion gas outlet 15 and the heat transfer fins inside the high temperature gas passage.
The gas flows from the exhaust passage 27 to the exhaust pipe 16 through the passages 24a and 25a of 24 and 25. The liquid refrigerant that has entered the inlet header pipe 19 through the inlet pipe 21 is divided into a plurality of vertical passages 18 from the lower portion of the refrigerant passage member 17, while the heat transfer fins 24 and 25 are formed into the passages 24a and 2a.
The heat of the high temperature gas flowing in 5a is transferred to the refrigerant passage member 17,
As a result, the refrigerant in the vertical passage 18 of the refrigerant passage member 17 is sufficiently heated from the lower portion near the inlet header pipe 19. Then, the heated liquid refrigerant starts vaporization and evaporation, and becomes a gas-liquid two-phase state in which bubbles are generated in the liquid. The generated bubbles rise in the vertical passage 18 due to the buoyancy effect, and in particular, since the combustion gas leaves the combustion gas outlet 15 from the combustion chamber 11 and then transfers heat to the refrigerant in the high temperature gas passage, the temperature of the combustion gas increases. To make the flow uniform,
Each part of the refrigerant passage member 17 can be uniformly heated, the refrigerant is evaporated smoothly and uniformly, the refrigerant is not locally overheated, and the non-powered transfer is surely performed, and the thermal decomposition of the refrigerant does not occur. Uniform heating also increases the bubble generation by reducing the flow resistance in the passage 18, the bubble rising force is strengthened and the natural circulation force is strengthened, and the liquid refrigerant that has not yet vaporized is passed to the upper part of the passage 18. A bubble pump action that sends the refrigerant occurs.

The length of the passage 25a of the heat transfer fin 25 is equal to the length of the heat transfer fin 24.
By setting the passage 24a longer than the length of the passage 24a, the gas passage resistance on the heat transfer fin 25 side is increased, so that the combustion gas flows uniformly through the heat transfer fins 24, 25. That is, the combustion gas passage resistance of the passage through which the combustion gas passes from the combustion chamber 11 through the combustion gas outlet 15 and through the high temperature gas passage to the exhaust pipe 16 can be optimally set by the length of the fin. Further, in this embodiment, the passage 25a of the heat transfer fin 25 on the exhaust pipe 16 side is made longer than the passage 24a of the heat transfer fin 24 over the entire region. for that reason,
Heat transfer fins 25 near the exhaust pipe 16 and passages for the exhaust pipe 16
The heat transfer fin 24 having a large passage resistance having 24a and 27 can be set to the same resistance, the combustion gas can be made to flow uniformly, and the heat transfer amount of each part of the heat transfer fin can be made uniform. In addition, the flow resistance of the combustion gas can be controlled by providing a distribution of the flow rate resistance according to the length of the fins according to the flow of the refrigerant. Further, the heat transfer partition wall 1 other than the portions where the heat transfer fins 24 and 25 are provided
The surface 3 also serves as a heat transfer surface, which absorbs heat more efficiently than the high temperature gas flowing in the high temperature gas passage and further heats the gas-liquid two-phase refrigerant in the passage 18 to further increase the natural circulation force. aisle
The refrigerant reaching the upper end of 18 flows into the outlet header pipe 20 and flows out from the outlet pipe 22 toward a radiator (not shown). As described above, not only the natural circulation is enhanced by uniformly heating the lower part of the vertical passage 18 from the upper part, but also the natural circulation force is further increased by strongly heating the heat transfer fins 25 in the lower part. In addition, the hot gas passage member 14
The heat transfer partition wall 13 is attached together with the combustion chamber 11 and the refrigerant passage member 17 is attached to the heat transfer partition wall 13 so that the heat of the hot gas from the combustion chamber 11 is transferred to the heat transfer fins 24, 25. Can be efficiently transmitted to the passage 18, and since the refrigerant passage member 17 has a multi-tube double wall structure, it is possible to prevent the refrigerant from leaking to the combustion gas portion. Further, the high temperature combustion chamber 11 and the passage 18 are connected to the high temperature gas passage member.
Since the gas is completely separated in the high temperature gas passage formed by 14, the refrigerant is not thermally decomposed or deteriorated due to local overheating, and abnormal temperature rise of the device can be prevented to improve reliability.

Further, the refrigerant passage member 17 is an aluminum multi-tube flat extrusion pipe having a large number of passages inside, and the heat transfer fins
24 and 25 are formed by bending a band-shaped aluminum plate in a wave shape, and the heat transfer partition wall 13 is assembled as a brazing sheet in which a brazing material is clad in advance on the front and back of the aluminum core material, and at the same time, heat is generated by integrally brazing. A heat exchanger that can be electrically connected, has excellent heat transfer performance without contact heat resistance, is lightweight, and is low in cost.

Further, the high temperature gas passage member 14 is a brazing sheet in which a brazing material is clad on one side of an aluminum core material in advance, and the heat from the combustion chamber 11 is transferred by being integrally formed with the heat transfer fins 24, 25 by brazing. Heat fin 2
Heat can be transferred to the passage 18 through 4,25 with high heat exchange efficiency, and the efficiency can be improved and the device can be made compact. The use of aluminum for the high-temperature gas passage member 14 and brazing with the heat transfer partition wall 13 has a simple structure and can maintain airtightness, exhaust gas does not leak, and safety is high.

In addition, a passage that communicates with the heat insulating material 26 of the combustion chamber 11 and the passage 18 of the refrigerant passage member 17 (for example, a forward pipe to a radiator of a sealed pipe).
When these are provided so as to be in close contact with each other, the heat radiated from the heat insulating material 26 is transferred to the refrigerant circuit, resulting in a more efficient system. By the way, the oil of the compressor is always dissolved in the refrigerant, and the oil gradually accumulates when the refrigerant is vaporized by the heater. When a large amount of oil accumulates, it impedes the vaporization and circulation of the refrigerant due to its viscosity and low heat conduction. Therefore, since the oil drain pipe 23 is provided so as to be connected to the inlet header pipe 19 at the bottom of the passage 18 of the refrigerant passage member 17, when the oil is collected in the heater, the oil is discharged from the oil drain pipe 23 together with the refrigerant. By reliably removing oil from the heater and maintaining uniform circulation of the refrigerant, thermal decomposition of the refrigerant due to local overheating can be eliminated and reliability can be improved.

EFFECTS OF THE INVENTION As described above, according to the present invention, a combustion chamber having one end side in communication with the burner connected to the fuel supply device, and a combustion gas outlet provided in communication with the other end side of the combustion chamber, A high temperature gas passage provided in communication with the combustion gas outlet and a plurality of upper and lower heat transfer fins provided in close contact with a heat transfer partition wall covering the high temperature gas passage in the high temperature gas passage and having a large number of vertical passages. A refrigerant passage member that is in close contact with the outer surface of the heat transfer partition wall, and a heat insulating material that covers the inner surface of the combustion chamber, and the passage length of any one of the plurality of heat transfer fins may be different. The heat transfer fin has a length longer than the passage length, and the following effects can be obtained.

That is, since the passage lengths of the plurality of heat transfer fins are different from each other, the passage length on the heat transfer fin side having a long passage is lengthened to increase the gas passage resistance. Flows evenly through the heat transfer fins. That is, the resistance of the combustion gas passing through the hot gas passage after exiting the combustion gas outlet from the combustion chamber can be optimally set by the length of the fin. Therefore, the passage resistance of each heat transfer fin can be set to the same resistance, the combustion gas can be made to flow uniformly, and the heat transfer amount of each part of the heat transfer fin can be made uniform. This prevents the refrigerant from decomposing and deteriorating due to local overheating, and enables highly efficient heat exchange. In addition, the flow resistance of the combustion gas can be controlled by providing a distribution of flow rate resistance depending on the length of the fins according to the flow of the refrigerant. Further, a plurality of heat transfer fins in close contact with the heat transfer partition are provided in the high temperature gas passage through which the combustion gas ejected from the combustion gas outlet provided in communication with the combustion chamber of the heat insulating structure passes, and the heat transfer partition and the refrigerant passage are provided. With a heat exchanger configured with members, the temperature and flow of the combustion gas can be made uniform, each part of the refrigerant passage member can be heated uniformly, the refrigerant can circulate smoothly, and the refrigerant is not overheated without powering. The transport can be performed reliably and the thermal decomposition of the refrigerant can be prevented. Uniform heating reduces the resistance of the flow in the passage of the refrigerant passage member to increase bubble generation, the bubble rising force is strengthened and the natural circulation force is strengthened, the heat exchange efficiency is increased, and the device is made compact. In addition, uniform heating prevents local abnormal overheating of the refrigerant, thereby improving reliability by preventing abnormal temperature rise of the device. Further, since the non-powered heat transfer is possible, the running cost can be reduced.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention.
FIG. 2 is a vertical cross-sectional view of the heat exchanger, FIG. 2 is a horizontal cross-sectional view of the refrigerant passage member, FIG. 3 is an exploded perspective view of the heat exchanger, FIG. 4 is a configuration diagram inside the hot gas passage, and FIG. FIG. 6 is a circuit diagram of a conventional refrigerant heating / heating device, and FIG. 6 is a perspective view of a conventional heat exchanger. 11 …… Combustion chamber, 12 …… Burner, 13 …… Heat transfer partition, 14 ……
Hot gas passage member, 15 ... Combustion gas outlet, 16 ... Exhaust pipe, 17 ... Refrigerant passage member, 18 ... Passage, 19 ... Inlet header pipe, 20 ... Outlet header pipe, 24, 25 ... Transmission Heat fins, 24a, 25a ... passages, 26 ... Insulation.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsunori Sakuratake 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A combustion chamber whose one end side communicates with a burner connected to a fuel supply device, a combustion gas outlet which communicates with the other end side of the combustion chamber, and a combustion gas outlet which communicates with this combustion gas outlet. A high temperature gas passage provided, a plurality of upper and lower heat transfer fins provided in close contact with the heat transfer partition wall covering the high temperature gas passage in the high temperature gas passage and having a large number of vertical passages, and an outer surface of the heat transfer partition wall. And a heat insulating material that covers the inner surface of the combustion chamber, and the passage length of any one of the plurality of heat transfer fins is greater than the passage length of the other heat transfer fins. A heat exchanger with a longer length.