JPH02169969A - Heat exchanger - Google Patents

Abstract

PURPOSE:To prevent thermal decomposition of refrigerant by composing the spontaneous circulation cycle of a refrigerant heater of a heat transfer partition member having many heat transfer fins in close contact with a high temperature gas passage for passing burnt gas injected from a burnt gas outlet communicating with a combustion chamber and a refrigerant passage member of a porous tube having longitudinal passages. CONSTITUTION:High temperature gas generated in a combustion chamber 10 is passed through a burnt gas outlet hole 13, passages 34, 35 between the heat transfer fins 22A, 22B of a high temperature gas passage 12, and discharged via exhaust passages 26, 27 from an exhaust tube 28. Liquid refrigerant fed through a refrigerant inlet tube 17 into an inlet header tube 19 is branched from the bottom of a refrigerant passage member 15 to many longitudinal passages 16. The heat transfer fins 22A, 22B transfers heat from the burnt gas in the high temperature gas passage 12 to the thermally coupled refrigerant passage member 15 to sufficiently heat the refrigerant in the longitudinal passages 16 of the refrigerant passage member 15. The liquid refrigerant heat thereat starts to be vaporized to become vapor/liquid mixture state for generating bubbles in the liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial 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 for combustion gas and a refrigerant and a plumber are connected through a sealed pipe 3, and the refrigerant is forcibly circulated by a refrigerant conveyor provided in the sealed pipe 3.

Figure 6 shows a conventional example of heat exchanger l (Japanese Unexamined Patent Publication No. 5
9-107167), a plurality of fins J are provided on the cylindrical inner peripheral surface extending in the horizontal direction, and a pipe holding part B and a pipe 7 through which the refrigerant flows are provided in the axial direction of the outer peripheral surface. The combustion gas flows horizontally and horizontally around the inner surface of the cylinder to heat the refrigerant flowing in the horizontally horizontal pipe 7 sent by the refrigerant heater.

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

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 by non-powered heat transfer, the natural circulation force due to the buoyancy 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 exchanger/like as shown in FIG. The gaseous components of the refrigerant in the state do not flow smoothly toward the outlet, resulting in stagnation of the refrigerant and local abnormal overheating.Also, since the combustion chamber and heat exchange section are integrated, the amount of heat exchanged does not reach the combustion state. Due to the uniformity of the film, local overheating occurs, leading to thermal decomposition of the refrigerant or abnormal temperature rises in the equipment, which pose problems in terms of equipment reliability.

The present invention solves these conventional problems by smoothly circulating the natural circulation cycle of a refrigerant heater heated with a burner or the like by increasing the natural circulation force due to the rise of air bubbles, and improving thermal efficiency by more efficient heat transfer. This technology ensures non-powered heat transfer and does not cause thermal decomposition of the refrigerant, and evenly guides high-temperature combustion gas from the combustion chamber to the heat exchange section to maintain uniform circulation of the refrigerant, causing thermal decomposition of the refrigerant. The aim is to create a highly reliable system without any problems.

Means for Solving the Problems The present invention provides a plate-shaped heat transfer partition member, fixes a refrigerant passage member in close contact with one surface, and attaches a combustion chamber end plate to a frame-shaped mounting annular edge on the other surface. is fixed, a high-temperature gas passage is formed between the heat transfer partition member and the end plate of the combustion chamber, a combustion gas outlet hole is bored in the center of the end plate of the combustion chamber, and a burner connected to a fuel supply device is installed. The combustion chamber housing is fixed, and heat transfer fins each having a large number of fin pieces are provided above and below the heat transfer partition member at a position corresponding to the combustion gas outlet hole, and between the fin pieces and between the heat transfer fins, heat transfer fins are provided. High-temperature gas passages are formed on the top and bottom, left and right sides, an exhaust section is provided at the bottom, header pipes are connected to the refrigerant passage member on the top and bottom, and a heat insulating material is provided on the inner wall of the combustion chamber housing. be.

Effect of the present invention With the above-described configuration, combustion gas passes through a natural circulation cycle of a refrigerant heater heated by a burner or the like, which is ejected from a combustion gas outlet hole provided in communication with a combustion chamber having an adiabatic configuration. The structure is composed of a heat transfer partition member having heat transfer fins formed as a large number of single fin pieces that are in close contact with the high-temperature gas passage, and a refrigerant passage member having a multi-hole pipe structure having vertical passages, so that the temperature and flow of the combustion gas can be controlled. It is possible to uniformly heat each part of the refrigerant passage member, to circulate the refrigerant smoothly, and to reliably carry out non-motorized heat transfer without locally overheating the refrigerant, so that thermal decomposition of the refrigerant does not occur. Then, the combustion gas outlet hole is provided with a heat transfer fin that is divided vertically by a large number of fin pieces to form a passage above and below, and the other of the upper and lower passages that are divided by the heat transfer fin is brought together through the outer periphery of the heat transfer fin. By providing an exhaust passage that communicates with the lower part of the heat transfer fins of the exhaust passage, it is possible to uniformly promote evaporation from the lower part of the refrigerant passage and increase the amount of refrigerant circulated.

The high temperature gas passage member on the inner wall of the high temperature gas passage is constituted by the combustion chamber, the high temperature gas passage is constituted by the heat transfer partition member forming the outer wall, and the high temperature gas passage is constituted by a refrigerant passage member in close contact with the heat transfer partition member. Due to the double wall structure, heat is transferred from the high temperature gas passage member on the inner wall to the refrigerant passage through the heat transfer fins, increasing heat transfer efficiency. The wall structure prevents refrigerant from leaking into the combustion gas section, and the high-temperature combustion chamber and refrigerant passage are completely separated by the high-temperature gas passage, resulting in a highly reliable system without thermal decomposition or deterioration of the refrigerant due to local overheating.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

1 is a cross-sectional view of an embodiment of the heat exchanger of the present invention, FIG. 2 is a cross-sectional view of a refrigerant passage member of the present invention, FIG. 3 is an exploded perspective view of the heat exchanger of FIG. 1, and FIG. The figure shows a cross-sectional view of the combustion gas passage section of the heat exchanger of FIG. 1.

In FIGS. 1 to 4, IO is a combustion chamber provided in communication with a burner t connected to a fuel supply device, IOA is a combustion chamber housing, // is a plate-shaped heat transfer partition member, /2A is a box-shaped combustion chamber end plate having a frame-shaped mounting annular edge /2B, and the mounting annular edge /2f3 is tightly fixed to the heat transfer partition member //, and the combustion chamber end plate /2A and A high temperature gas passage 12 is formed between the heat transfer partition members 77. A combustion gas outlet hole /3 is formed in the center of the combustion chamber end plate 72A, and an exhaust passage /4 is provided in the high temperature gas passage /2.

lj is a refrigerant passage member thermally connected to the outer surface of the heat transfer partition member ll, and is provided with a large number of vertical passages 16. /7 is an inlet header pipe provided at the lower end of refrigerant passage member /6, and 78' is refrigerant passage member l! These are outlet header pipes installed at the upper end, each of which is connected to an outlet pipe 20, which is connected to the refrigerant circuit, and the other end of the inlet header pipe 7 is bent downward to drain oil. tube 21
This is provided. Inlet header pipe 17 and outlet header pipe/
The ♂ are connected to each other by a longitudinal passage /6.

22, 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 fin pieces. The remaining inner wall surface of the combustion chamber 10 that is not in contact with the high temperature gas passage/2 is provided with a heat insulating material 23 that covers the entire surface.

The combustion gas outlet hole 13 is divided vertically by a plurality of fin pieces to form a passage above and below, and the heat transfer fin 22A122B, and the upper and lower passages 2≠, which are divided by these fins, are connected to the other of the heat transfer fins 22A, 22f3. Exhaust passages 27 that pass through the outer periphery and converge. ．． 27 and an exhaust pipe 2r communicating with the lower part of the heat transfer fins 22B.The operation of the heat exchanger of the present invention will be described.

In the above configuration, the fuel supplied by the fuel supply device is supplied to the burner? The high temperature gas generated in the combustion chamber IO passes through the combustion gas outlet hole 13, passes through the passage 2≠, 2j between the heat transfer fins 22A122f3 of the high temperature gas passage/2,
Exhaust from the exhaust pipe 2g from the exhaust passages 2o and 27.

The liquid refrigerant that has entered the inlet header pipe through the refrigerant inlet pipe is divided into a number of vertical passages from the lower part of the refrigerant passage member. Heat is transferred from the combustion gas to the thermally connected refrigerant passage member /j, and the refrigerant in the longitudinal passage /4 of this refrigerant passage member I 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 l6 due to the buoyancy effect, and in particular, the combustion gas is transferred from the combustion chamber 10 to the refrigerant in the high temperature gas passage /2 after exiting the combustion gas outlet hole /3. Since the temperature of the combustion gas is constant and stable, the temperature and flow of the combustion gas can be made uniform by ejecting it from one outlet, and each part of the refrigerant passage member can be uniformly heated, allowing the refrigerant to flow smoothly and uniformly. To evaporate the refrigerant and to reliably carry out non-motive heat transfer without locally overheating the refrigerant, thereby preventing thermal decomposition of the refrigerant.

Uniform heating also reduces the flow resistance in the passage/6, increasing bubble generation, increasing the bubble rising force, strengthening the natural circulation force, and moving the liquid refrigerant that has not yet vaporized into the passage/6. A bubble pump action occurs that sends the refrigerant to the top. Furthermore, the heat transfer partition members other than the heat transfer fins 22A and 122B provided at the upper and lower parts of the passageway/B have a total surface heat transfer area, which absorbs heat more efficiently than the heated fluid flowing through the high temperature gas passageway 12, and the air inside the passageway/6 The refrigerant in the liquid two-phase state is further heated to further increase the natural circulation force.

The refrigerant that has reached the upper end of the passageway /6 flows into the outlet header pipe /♂ 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 passageway/B, not only the natural circulation is enhanced, but also the natural circulation force is further increased by strongly heating the lower part by the heat transfer fins 22B.

Exhaust pipe 2 from combustion gas outlet hole/3! Passage 2 up and down the combustion gas passage leading to r! ;Divided by S26, 2g exhaust pipe on the bottom
Since the combustion gas outlet hole 13 is provided with a passage 2! The path to the exhaust pipe 2g can be shortened through the
Flow through the passage 2 more than Otsu. Therefore, the refrigerant in the passage 16 is sufficiently and uniformly heated in the lower part, so that the bubble pump action is strengthened and the circulation force can be increased. Then, the combustion gas that passed through the heat transfer fins 22A122f3 passes through the exhaust passages 2 and 2.
7 also passes through the heat transfer partition member/l and heat is transferred to the refrigerant, so the heat transfer area becomes larger and the heat exchange efficiency can be increased.

Further, the inner wall of the high temperature gas passage /2 is constituted by the combustion chamber end plate /2A of the combustion chamber 10, and the heat transfer partition member // constituting the outer wall, and the refrigerant passage member l! which is in close contact with this heat transfer partition member //! The heat transfer fins 22 are connected from the inner wall to the double wall structure.
The heat transfer efficiency increases because the heat is transferred to the refrigerant passage/B through A and 22B, and the double wall structure composed of the refrigerant passage member/J with a multi-hole tube structure prevents the refrigerant from leaking into the combustion gas section and reduces high temperature. Since the combustion chamber 10 and the refrigerant passage/6 are completely separated by the high temperature gas passage/2, there is no thermal decomposition or deterioration of the refrigerant due to local overheating, and the system is highly reliable as it prevents abnormal temperature rises in equipment. The remaining casing i that does not come into contact with the high temperature gas passage 12 of 10
The inner wall surface of the OC is covered with a heat insulating material 23 to prevent heat radiation.

Furthermore, the refrigerant passage member 16 is made of a multi-hole flat extruded tube made of aluminum with many holes inside, and the heat transfer fins 22A
, 22B is constructed by bending a band-shaped aluminum plate into a wave shape, and the heat transfer partition member// is a heat transfer plate using this material as a plating sheet in which the front and back sides of an aluminum core material are clad in advance with brazing filler metal. Heat transfer fins 22A, 22B made of aluminum and a refrigerant passage member made of a multi-hole flat extruded tube made of aluminum are provided on the inner and outer surfaces of the partition wall member//.
! It is possible to thermally connect the heat exchanger by assembling the heat exchanger and integrally brazing it at the same time, and it is possible to put into practical use a heat exchanger that has heat transfer performance with no contact thermal resistance and is lightweight and low cost.

Further, the combustion chamber 10 forming the inner wall of the high temperature gas passage/2
Combustion chamber end plate / 2A, which becomes the outer wall of the combustion chamber, is used as a plating sheet in which one side of an aluminum core material is pre-clad with brazing material, and integrated with heat transfer fins 2.2A and 22B by body brazing. With this configuration, heat from the combustion chamber 10 is transferred to the heat transfer fins 22 through 22B and the combustion chamber end plate/2A to the refrigerant passage/B with high heat exchange efficiency, increasing efficiency and making the equipment more compact. becomes.

The combustion chamber 10 that constitutes the inner wall of the high-temperature gas passage
Combustion chamber end plate 7.2 of the outer wall of the combustion chamber is integrally brazed with aluminum and 1-1 heat transfer partition member// with a simple structure, and it is possible to maintain airtightness and ensure safety without leaking exhaust gas. 0 In addition, a passage communicating with the passage /6 of the refrigerant passage member /j (for example, a sealed Conduit 3
By configuring the radiator 3 and the inlet pipe) in close contact with each other, the heat radiated to the outside from the heat insulating material 23 is transferred to the refrigerant circuit, resulting in an even more efficient system.

Compressor oil is always dissolved in the refrigerant, and as the refrigerant is vaporized in the heater, the oil gradually accumulates. When a large amount of oil accumulates, its viscosity and low heat conductivity impede the vaporization and circulation of the refrigerant.

The refrigerant passage member /j is equipped with an oil drain pipe 2/ that bends downward and connects to the inlet header 17 at the bottom of the refrigerant passage /B, so if oil accumulates in the heater, it will be discharged from the oil drain pipe together with the refrigerant. and ensure that oil is removed from the heater.
By maintaining uniform circulation of the refrigerant, thermal decomposition of the refrigerant due to local overheating does not occur, resulting in a highly reliable system.

Effects of the Invention According to the configuration of the present invention, (1) a heat transfer partition wall of the high temperature gas passage through which combustion gas passes through the combustion gas ejected from a combustion gas outlet hole provided in communication with a combustion chamber having an adiabatic structure; The temperature and flow of combustion gas is controlled by a heat exchanger configured by closely adhering a refrigerant passage member with a multi-hole tube structure having vertical passages to a heat transfer partition member having heat transfer fins forming a large number of closely attached fin pieces. It is possible to uniformly heat each part of the refrigerant passage member, circulate the refrigerant smoothly, and ensure non-motorized heat transfer without causing local overheating of the refrigerant, and uniform heating without causing thermal decomposition of the refrigerant. In addition, bubble generation is increased by reducing the flow resistance in the passage / 6, and in particular, by providing upper and lower combustion gas passages,
By installing the exhaust pipe close to the bottom, the bottom of the refrigerant passage member is heated uniformly and strongly, so the rising force of the -layer bubbles is strengthened, the natural circulation force is strengthened, the heat exchange efficiency is increased, and the equipment is made more compact. Furthermore, by preventing local abnormal overheating of the refrigerant through uniform heating, it is possible to improve reliability by preventing thermal decomposition of the refrigerant or abnormal temperature rise of equipment.

(2) Non-powered heat transfer is possible due to the bubble pump action of the rising bubble flow, allowing heating at low running costs.

(3) The double-wall structure in which the refrigerant passage member /j is integrated with the heat transfer partition member prevents leakage of refrigerant into the combustion gas section, and the high-temperature combustion chamber and refrigerant passage are completely separated by the high-temperature gas passage. It is a highly reliable system that eliminates thermal decomposition and deterioration of the refrigerant due to local overheating, and prevents abnormal temperature rises in equipment.It has a simple configuration, maintains airtightness, prevents exhaust gas from leaking, and prevents refrigerant from leaking. Even in the event of a leak, the refrigerant gas does not come into direct contact with the fire, making it highly safe.

(4) The combustion chamber end plate/2A, which constitutes the inner wall of the high-temperature gas passage and serves as the outer wall of the combustion chamber, is made of this material as a plating sheet in which one side of an aluminum core is pre-clad with a brazing material, and integrally brazed. By integrating the heat transfer fin outer wall and exhaust passage, heat from the combustion chamber is transferred to the refrigerant passage through the heat transfer fins and exhaust passage with high heat exchange efficiency, increasing efficiency and making equipment more compact. Therefore, integral brazing has a simple structure, can maintain airtightness, and has high safety with no leakage of exhaust gas.

(5) Construct a passage communicating with the passage of the refrigerant passage member (for example, a closed pipe leading to a radiator) closely around the outer periphery of the heat insulating material covering the remaining inner wall that is not in contact with the high-temperature gas passage of the combustion chamber. Then, the heat radiated externally from the insulation material is transferred to the refrigerant circuit, making the system even more efficient.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the heat exchanger of the present invention, Fig. 2 is a sectional view of a refrigerant passage member of the invention, Fig. 3 is an exploded perspective view of the heat exchanger of Fig. 1, and Fig. 4 1 is a sectional view of a combustion gas passage portion of a heat exchanger, FIG. 5 is a circuit diagram of a conventional refrigerant heater, and FIG. 6 is an external perspective view of a conventional refrigerant heater. ? = Burner 10: Combustion chamber, //: Heat transfer partition member, /2: High temperature gas passage, /2A: Combustion chamber end plate, /3: Combustion gas outlet hole, /4t
: Exhaust part, /j: Refrigerant passage member, /B: Passage, /7
: Inlet header pipe, /♂: Outlet header pipe, /ri, 2
0 Two-person tube, outlet tube, Kononi oil drain tube, 22A, 22B = heat transfer fin.

Claims (1)

[Claims] A plate-shaped heat transfer partition member is provided, a refrigerant passage member is fixed in close contact with one surface, and a combustion chamber end plate is fixed at the frame-shaped mounting annular edge on the other surface, and the combustion chamber is connected to the heat transfer partition member. A high-temperature gas passage is formed between the end plates of the combustion chamber, a combustion gas outlet hole is formed in the center of the end plate of the combustion chamber, and a combustion chamber housing equipped with a burner connected to a fuel supply device is fixed. A heat transfer fin having a large number of fin pieces is provided above and below the heat transfer partition member at a position corresponding to the gas outlet hole, and high temperature gas passages are formed between the fin pieces and above, below, left and right of the heat transfer fin. The heat exchanger is provided with an exhaust part in the lower part, header pipes are connected above and below to the refrigerant passage member, and a heat insulating material is provided on the inner wall of the combustion chamber casing.