JP2845563B2 - Heat exchanger - Google Patents

Description

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 a combustion gas and uses the refrigerant in a cooling and heating device.

2. Description of the Related Art There is a refrigerant heating / heating machine as shown in FIG. 5 in which a refrigerant is used as a fluid to be heated and heated by a combustion gas to evaporate and vaporize a liquid refrigerant to select heat by latent heat for heating.
In this method, a heat exchanger 1 for combustion gas and a refrigerant and a radiator 2 are connected by a closed conduit 3 and the refrigerant is forcibly circulated by a refrigerant carrier 4 provided in the closed conduit 3. FIG.
This shows a conventional example of the heat exchanger 1 (Japanese Patent Laid-Open No. 59-107167).
A plurality of fins 5 are provided on a cylindrical inner peripheral surface extending in the horizontal direction extruded from a material such as aluminum, and a pipe holding portion 6 and a pipe 7 through which a refrigerant flows are provided in the axial direction of the outer peripheral surface. The combustion gas from the burner 8 flows in the horizontal horizontal direction to the cylindrical inner surface 9 to heat the refrigerant flowing in the horizontal horizontal pipe 7 sent by the refrigerant heater 4.

However, in this heating system, an external power is required for the refrigerant transport unit, and it is desired to reduce the running cost during the heating operation. Therefore, the applicant has first
It has been proposed to arrange a vertical refrigerant passage member outside the heat transfer partition tube having an enlarged slope below the parallel approaching surface with heat transfer fins. (Japanese Patent Application No. 61-249961) Problems to be Solved by the Invention To reduce the running cost during the heating operation, it is effective to eliminate the external power for transporting the refrigerant and carry out the heat transport without power. In the case of performing heating and heating of a refrigerant by non-powered heat transfer, natural circulation force due to buoyancy of a gas refrigerant generated by heating a liquid refrigerant is important. Conventionally, this type of heating device has a configuration like a refrigerant heating heat exchanger 1 as shown in FIG. 6 and the refrigerant flows through a horizontally extending pipe 7.
The gas component of the refrigerant in the gas-liquid two-layer mixed state being heated does not flow smoothly toward the outlet, causing refrigerant stagnation, causing local abnormal overheating, and the combustion chamber and the heat exchange unit are integrated. Therefore, since the heat exchange amount is not uniform depending on the combustion state, there is a problem in reliability of the equipment such as local overheating, thermal decomposition of the refrigerant or abnormal temperature rise of the equipment. Also, Japanese Patent Application
In the case of 61-249961, the heat transfer fin is constructed by bending a strip-shaped aluminum plate into a wave shape, so even if the precision of parts on the parallel surface with the heat transfer fin is highly controlled, it can be used during high temperature brazing. Deformation occurred, and it was difficult to completely adhere the heat transfer fins to the parallel approach surface over the entire area. Therefore, not only does the heat exchange efficiency decrease in accordance with the ratio of the heat transfer fins that do not adhere, but also the heat transfer fins that do not adhere become high in temperature and deform to cause stress in the entire heat exchanger, causing damage, or blocking the exhaust gas passage and burning. An abnormal condition has occurred. The present invention solves such a conventional problem, and a structure in which the entire area of the heat transfer fins and the adjacent surface is completely adhered to each other, so that the heat is uniformly heated by the heat of the combustion gas of the refrigerant heater heated by the burner or the like, and the efficiency is improved. An object of the present invention is to improve and stabilize thermal efficiency by transferring heat, and to provide a highly reliable system without generating a local high temperature of a fin.

Means for Solving the Problems The present invention provides a combustion chamber provided in communication with a burner connected to a fuel supply device, a combustion gas outlet provided in communication with a side surface of the combustion chamber, and a communication with the combustion gas outlet. A high-temperature gas passage, a heat transfer fin formed by dividing a hot gas passage through which a combustion gas passes through a plurality of fins in close contact with an outer peripheral heat transfer partition of the high-temperature gas passage, and an inner wall of the high-temperature gas passage. The outer wall of the high-temperature gas passage is constituted by a heat transfer partition and a double-walled structure formed by a refrigerant passage member in close contact with the outer heat transfer partition, and the remaining portion of the combustion chamber not in contact with the high-temperature gas passage. A heat insulating material covering an outer surface, and the heat transfer fins are formed of an extruded material, and are integrated with the heat transfer partition.

Function The present invention provides a heat-transfer fin made of an extruded material by the above-described structure, so that each dimension of the heat-transfer fin can be processed with high precision, and a residual stress as in the case of being bent in a wave shape. Therefore, the heat transfer fins and the heat transfer partition can be reliably brought into contact with all the end surfaces when brazing is performed so as to be integrated with the heat transfer partition. Therefore, the fixing pressure of the positioning jig during brazing can be set high, and the heat transfer fins and heat transfer partition can be brazed with high pressure and all surfaces in close contact. In all parts of the heat fin, the heat of the combustion gas is quickly transferred to the heat transfer partition. For this reason, all the portions of the heat transfer fins effectively act to improve and stabilize the thermal efficiency, and a highly reliable system is obtained without generating a local high temperature of the fin due to non-adhesion with the fin heat transfer partition. Further, the heat of the combustion gas applied to the inner wall is quickly transferred to the heat transfer partition in all parts of the inner wall by integrally forming the inner wall of the high-temperature gas passage and the heat transfer fin with the extruded molding material. Therefore, all parts of the inner wall also work effectively to improve and stabilize the thermal efficiency, and a high-reliability system can be obtained without generating a local high temperature of the inner wall due to non-contact between the fin and the inner wall. A natural circulation cycle of a refrigerant heater heated by a burner or the like, a large number of intimately attached to the outer peripheral heat transfer partition of the high-temperature gas passage through which combustion gas ejected from a combustion gas outlet provided in communication with a combustion chamber having an adiabatic configuration passes. By providing the exhaust pipe communicating with the fins, evaporation can be uniformly promoted from the refrigerant passage and the circulation amount of the refrigerant can be increased. The inner wall of the high-temperature gas passage is constituted by the combustion chamber and the outer heat transfer wall constituting the outer wall and the double wall structure constituted by the refrigerant passage member which is in close contact with the outer heat transfer partition, through the heat transfer fins from the inner wall. The heat transfer efficiency is increased because the heat is transferred to the coolant passage, and the double-walled construction of the coolant passage member having a multi-hole tube structure prevents the coolant from leaking into the combustion gas portion and connects the high-temperature combustion chamber and the coolant passage with the high-temperature gas passage. Therefore, the system is highly reliable without causing thermal decomposition and deterioration of the refrigerant due to local overheating.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 4, reference numeral 10 denotes a combustion chamber provided in communication with a burner 8 connected to a combustion supply device, 11 denotes a heat transfer partition, 12A and 12B denote high-temperature gas passages, and The exhaust gas pipe 13 communicates with a combustion gas outlet 13 and an exhaust pipe 24, and has an outer heat transfer partition 11 and an inner wall 14 partitioning the inner side from the combustion chamber 10. Reference numeral 15 denotes a refrigerant passage member thermally connected to the outer surface of the heat transfer partition 11, and a number of vertical passages 16 are provided. Reference numeral 17 denotes an inlet header pipe provided at the lower end of the refrigerant passage member 16, and 18 denotes 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, which are connected to the refrigerant circuit. An oil drain tube 21 is provided at the other end of the inlet header. The inlet header pipe 17 and the outlet header pipe 18 communicate with each other by a vertical passage 16. 22A and 22B are heat transfer fins provided so as to be in thermal contact with the inside of the heat transfer partition 11, and an extruded material forming a passage with a large number of fins is integrally formed on the heat transfer partition 11 by brazing or the like. Make up. The remaining outer surface of the combustion chamber 10 which is not in contact with the high-temperature gas passage 12 is provided with a heat insulating material 23 covering the entire surface. In addition, the hot gas passages 12A and 12B
A guide path 25 communicating from A to the exhaust pipe 24, and a guide path 26 communicating from the passage 12B to the exhaust pipe 24 through the outer periphery of the fins 22A and 22B are provided.

In the above configuration, the fuel supplied by the fuel supply device is burned by the burner 8, and the high-temperature gas generated in the combustion chamber 10 passes through the combustion gas outlet 13 and passes through the heat transfer fins 22A, 22B of the high-temperature gas passages 12A, 12B. Then, the air flows from the exhaust passages 25 and 26 to the exhaust pipe 24. The liquid refrigerant that has entered the inlet header pipe 17 through the refrigerant inlet pipe 17 is diverted from the lower part of the refrigerant passage member 15 to a plurality of vertical passages 16, and the heat transfer fins 22 </ b> A and 22 </ b> B generate combustion gas in the hot gas passage 12. Then, the heat is transferred from the thermally connected heat transfer partition 11 to the refrigerant passage member 15, and the refrigerant is heated in the vertical passage 16 of the refrigerant passage member 15 from the lower portion near the inlet header 17. Then, the heated liquid refrigerant starts vaporizing and evaporating, and bubbles are generated in the liquid to be in a gas-liquid two-phase state. Due to the buoyancy effect, the generated bubbles rise upward from below in the passage 16 provided in the longitudinal direction, and the refrigerant does not locally overheat, thereby reliably performing powerless heat transfer, and does not cause thermal decomposition of the refrigerant. Further passage 16
The upper and lower surfaces of the heat transfer fins 22A and 22B other than the heat transfer fins 22A and 22B also serve as heat transfer areas, and the hot gas passages 12A and 1
Heat is more efficiently absorbed from the heating fluid flowing through 2B, and the refrigerant in the gas-liquid two-phase state in the passage 16 is further heated to further increase the natural circulation force. The refrigerant that has reached the upper end of the passage 16 flows into the outlet header tube 18 and flows out of the refrigerant outlet tube 20 toward a radiator (not shown). Since the heat transfer fins 22A and 22B are formed of an extruded material, the dimensions of the heat transfer fins can be processed with high precision, and no residual stress is generated as in the case where the heat transfer fins are bent in a wave shape. When brazing to be integrated with the thermal bulkhead 11, the heat transfer fins 22
A, 22B and the heat transfer partition 11 can be reliably contacted on all end faces. Therefore, the fixing pressure of the positioning jig during brazing can be set to a large value, and the heat transfer fins 22A and 22B and the heat transfer partition 11 can be brazed in a state where all surfaces are in close contact at high pressure, so that the entire area is completely adhered. Thus, the heat of the combustion gas is quickly transferred to the heat transfer partition 11 in all the portions of the heat transfer fins 22A and 22B. Therefore, heat transfer fins
All parts of 22A, 22B work effectively to improve and stabilize thermal efficiency, and a highly reliable system that does not generate local high temperature of fins due to non-adhesion between fins 22A, 22B and heat transfer partition 11 Become. Further, the fin pitch and the fin thickness can be freely set by configuring the fin with an extruded material. By changing the pitch of the fins in accordance with the flow of the refrigerant, the distribution of the heat transfer capability is provided, and the heat exchange performance can be controlled regardless of the flow distribution of the combustion gas. Since the refrigerant flows mostly in the vicinity of the outlet pipe and the flow rate at the end of the flow is small, uniform heat transfer efficiency can be achieved by sequentially reducing the fin pitch in this portion, and overheating does not occur and the efficiency is high. Uniform heating also increases the bubble generation by uniformizing the flow in the passage 16 and reducing the flow resistance, increasing the bubble rising force and increasing the natural circulation force, and increasing the bubble rising force and increasing the natural circulation force. At the same time, a bubble pump action is generated that sends the refrigerant to the upper portion of the passage 16 with the liquid refrigerant that has not been vaporized yet.
Heat transfer fins provided at the top and bottom of the passage 16
The entire surface of the heat transfer partition 11 other than 22A and 22B also becomes a heat transfer area, absorbs heat more efficiently than the heating fluid flowing through the high-temperature gas passage 12, further heats the gas-liquid two-phase refrigerant in the passage 16, and further increases the natural circulation force. Increase. The refrigerant that has reached the upper end of the passage 16 flows into the outlet header tube 18 and passes through the refrigerant outlet tube 20 to a radiator (not shown).
Spill out towards. In this way, not only the natural circulation is enhanced by uniformly heating from the lower part to the upper part of the vertical passage 16, but also the natural circulation is achieved by reducing the pitch of the heat transfer fins 22 </ b> B at the lower part to further intensify the heating. The power can be further increased. Further, the inner wall of the high-temperature gas passage 12 is constituted by the combustion chamber 10 and an outer peripheral heat transfer partition 11 which constitutes an outer wall, and a double wall configuration constituted by a refrigerant passage member 15 which is in close contact with the outer peripheral heat transfer partition 11, From the heat transfer fins 22A and 22B to the refrigerant passage 16 to increase the heat transfer efficiency, and the double-walled structure composed of the refrigerant passage member 15 having a multi-hole tube structure prevents the refrigerant from leaking into the combustion gas portion and has a high temperature. The combustion chamber 10 and the refrigerant passage 16 are connected to the hot gas passages 12A and 12B.
This is a highly reliable system that does not cause thermal decomposition and deterioration of the refrigerant due to local overheating, or prevents abnormal temperature rise of equipment. High temperature gas passage 12 of combustion chamber 10
The remaining outer surfaces other than the inner wall 14 in contact with A and 12B are covered with a heat insulating material 23 to prevent heat radiation.

Further, the refrigerant passage member 16 is an aluminum multi-hole flat extruded tube having a large number of holes therein, and the heat transfer fins 22A, 22A
2B is made of extruded aluminum material, and the heat transfer partition 11 is made of aluminum on the inner and outer surfaces of a heat transfer partition 10 using this material as a brazing sheet in which a brazing material is pre-clad on the front and back of an aluminum core. By assembling using the heat transfer fins 22A, 22B and the refrigerant passage member 16 of the multi-hole flat extruded pipe made of aluminum and simultaneously brazing integrally, the pitch of the fins can be easily changed and thermally connected, and the contact thermal resistance is reduced. A heat exchanger having no heat transfer performance can be practically used at a low cost and at a low cost. As the shape of the extruded material made of aluminum as the heat transfer fins 22A and 22B, multi-holes as shown in FIG. 2 are provided to increase the heat transfer fin area per unit,
As shown in FIG.
The fins are projected on both sides in a skewer shape as shown in FIG. 4 to increase the heat transfer fin area per unit.

2 and 3, the heat transfer fins 22A, 22B and the inner wall 14 are integrated with each other by forming the inner wall 14 of the high-temperature gas passages 12A, 12B using an extruded material as shown in FIGS. The heat from the combustion chamber 10 is transferred to the refrigerant passage 16 with high heat exchange efficiency through the heat transfer fins 22A and 22B, thereby increasing the efficiency and reducing the size of the equipment. Further, the oil of the compressor is always dissolved in the refrigerant, and the oil gradually accumulates when the refrigerant is vaporized by the heater. If a large amount of oil accumulates, its viscosity and low heat conduction hinder vaporization and circulation of the refrigerant. Since the oil drain pipe 21 connected to the inlet header 17 at the bottom of the refrigerant passage 16 of the refrigerant passage member 15 is provided, when oil accumulates in the heater, the oil is discharged together with the refrigerant from the oil drain pipe to reliably heat the oil. It is a highly reliable system that does not cause thermal decomposition of the refrigerant due to local overheating by maintaining the uniform circulation of the refrigerant by removing it from the vessel.

Effects of the Invention As described above, according to the heat exchanger of the present invention, a combustion chamber provided in communication with a burner connected to a fuel supply device, and a combustion gas outlet provided in communication with a side surface of the combustion chamber, A high-temperature gas passage provided in communication with the combustion gas outlet, a heat transfer fin having a passage formed by dividing the high-temperature gas passage through which a combustion gas passes by a number of fins closely attached to an outer peripheral heat transfer partition; An inner wall of the passage is formed by the combustion chamber, an outer peripheral heat transfer partition constituting an outer wall of the high-temperature gas passage, and a double-walled structure formed by a refrigerant passage member in close contact with the outer peripheral heat transfer partition; The following effects can be obtained by a heat insulating material that covers the remaining outer surface that is not in contact with the passage, and the heat transfer fins are formed of an extruded material and integrated with the heat transfer partition.

(1) Since the heat transfer fins are made of extruded material, the dimensions of the heat transfer fins can be processed with high precision, and no residual stress is generated as in the case where the heat transfer fins are bent in a wave shape. When brazing to integrate with the partition walls, the heat transfer fins and the heat transfer partition walls can be securely in contact with all end surfaces. Therefore, the fixing pressure of the positioning jig during brazing can be set high, and the heat transfer fins and heat transfer partition can be brazed with high pressure and all surfaces in close contact. In all parts of the heat fin, the heat of the combustion gas is quickly transferred to the heat transfer partition. For this reason, all the portions of the heat transfer fins effectively act to improve and stabilize the thermal efficiency, and a highly reliable system is obtained without generating a local high temperature of the fin due to non-adhesion with the fin heat transfer partition.

(2) By forming the inner wall of the high-temperature gas passage integrally with the heat transfer fins using an extruded molding material, the heat of the combustion gas applied to the inner wall is quickly transferred to the heat transfer partition in all portions of the inner wall. As a result, the inner wall is also effective at all portions to improve and stabilize the thermal efficiency, and a high-reliability system is obtained without generating a local high temperature of the inner wall due to the non-adhesion between the fin and the inner wall.

(3) The pitch and the fin thickness of the fin can be freely set by configuring the fin with an extruded material. By changing the pitch of the fins in accordance with the flow of the refrigerant, the distribution of the heat transfer capability is provided, and the heat exchange performance can be controlled regardless of the flow distribution of the combustion gas. Since the refrigerant flows mostly in the vicinity of the outlet pipe and the flow rate at the end of the flow is small, uniform heat transfer efficiency can be achieved by successively reducing the fin pitch in this portion.

(4) The outer periphery of a large number of heat transfer fin high temperature gas passages which are in close contact with the outer periphery of the high temperature gas passage through which the combustion gas passes through a combustion gas outlet provided in communication with the combustion chamber having the heat insulation structure. A heat exchanger composed of a refrigerant passage member having a multi-hole tube configuration having a heat transfer partition and a vertical passage can make the temperature and flow of the combustion gas uniform, uniformly heat the respective parts of the refrigerant passage member, smoothly circulate the refrigerant, In addition, uniform heating without causing thermal decomposition of the refrigerant without causing local overheating of the refrigerant and without thermal decomposition of the refrigerant is also achieved. Is enhanced, the natural circulation force is strengthened, the heat exchange efficiency is increased, and the equipment can be made more compact. In addition, uniform heating prevents the refrigerant from overheating locally, resulting in thermal decomposition of the refrigerant or abnormal temperature of the equipment It is possible to improve the reliability by raising prevented.

(5) The non-powered heat transfer becomes possible by the bubble pump action by the rising bubble flow, and the heating with low running cost can be performed. In addition to increasing the natural circulation by uniformly heating from the lower part to the upper part of the vertical passage 16, the natural circulation force is further increased by making the pitch of the heat transfer fins 22 B smaller at the lower part to heat more strongly. Can be increased.

(6) The refrigerant wall member 15 is integrally formed with the outer peripheral heat transfer partition to prevent the refrigerant from leaking into the combustion gas portion by the double wall configuration, and to completely separate the high temperature combustion chamber and the refrigerant passage by the high temperature gas passage to locally overheat. It is a highly reliable system that does not cause the thermal decomposition and deterioration of the refrigerant due to the prevention of abnormal temperature rise of the equipment, has a simple configuration, can maintain airtightness, does not leak exhaust gas, and has a flame even if the refrigerant leaks The refrigerant gas does not come into direct contact with the fuel cell and has high safety.

(7) Since the fins are made of extruded material, the residual stress can be removed and all the fins can be in close contact with each other.
The heat transfer fins are high in safety and durability without being locally heated to a high temperature and deformed to generate stress in the entire heat exchanger and to cause damage or block the exhaust gas passage to cause abnormal combustion conditions.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a heat exchanger showing one embodiment of the present invention, FIG. 2 is a cross-sectional view of a refrigerant passage member and a heat transfer fin portion of the heat exchanger, and FIGS. FIG. 5 is a cross-sectional view of a heat transfer fin of the same device, FIG. 5 is a circuit configuration diagram of a conventional refrigerant heater, and FIG. 6 is an external perspective view of the conventional refrigerant heater. 8 Burner, 10 Combustion chamber, 11 Heat transfer bulkhead, 12
A, 12B: High-temperature gas passage, 13: Combustion gas outlet, 14 ...
Inner wall, 15: refrigerant passage member, 16: passage, 22A, 22B ...
fin.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadayoshi Ohashi 6,224, Kaiyamacho, Sakai City, Osaka Prefecture Inside Showa Aluminum Co., Ltd. (72) Inventor Minoru Takayama 6,224, Kaiyamacho, Sakai City, Osaka Prefecture Aluminium Showa (56) References JP-A-3-51664 (JP, A) JP-A-63-105395 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24H 9/00 F25B 41/00 F28D 7/00

Claims (2)

(57) [Claims] 1. A combustion chamber provided in communication with a burner connected to a fuel supply device, a combustion gas outlet provided in communication with a side surface of the combustion chamber, and a high-temperature gas provided in communication with the combustion gas outlet. A passage, a heat transfer fin having a passage formed by dividing a large number of fins in close contact with an outer peripheral heat transfer partition of the high temperature gas passage through which the combustion gas passes, and an inner wall of the high temperature gas passage comprising the combustion chamber; An outer peripheral heat transfer partition constituting an outer wall of the high-temperature gas passage and a double wall configuration formed by a refrigerant passage member in close contact with the outer peripheral heat transfer partition, and a heat insulating material covering the remaining outer surface of the combustion chamber not in contact with the high-temperature gas passage. A heat exchanger in which the heat transfer fins are formed of an extruded material and are integrated with the heat transfer partition. 2. The heat exchanger according to claim 1, wherein the inner wall of the high-temperature gas passage and the heat transfer fin are integrally formed by an extruded material.