JPH0566058A - Heat exchanger - Google Patents

Abstract

PURPOSE:To normalize the protection of a heat exchanger and the operation of a system by immediately sensing if refrigerant is heated such as if the refrigerant is insufficient in a refrigerant heater in the exchanger for heating the refrigerant by high temperature gas such as combustion gas, etc., to utilize it for a room cooler/heater. CONSTITUTION:The heat exchanger comprises a heat transfer fitting 24 in close contact with the outer peripheral heat transfer partition wall 11 of a high temperature gas passage 12, and temperature sensing means 25 in a refrigerant passage member 15 opposed to the fitting 24. Since the temperature of the means 25 is abruptly raised and the means 25 is operated without response delay, the refrigerant can be, if the refrigerant is heated, immediately sensed at its temperature thereby to normalize the protection of the exchanger and the operation of a system, and thermal decomposition, deterioration of the refrigerant do not occur.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A conventional refrigerant heating / heating machine as shown in FIG. 4 is one in which a refrigerant is used as a fluid to be heated and is heated by combustion gas to evaporate a liquid refrigerant to carry heat by latent heat for heating. There is. This is a heat exchanger 1 for combustion gas and refrigerant
And the radiator 2 are connected to each other by the sealed pipeline 3, and the refrigerant is forcedly circulated by the refrigerant carrier 4 provided in the sealed pipeline 3. FIG. 5 shows a conventional example of the heat exchanger 1 (Japanese Patent Laid-Open No. 59-107167), in which a plurality of fins 5 are provided on a cylindrical inner circumferential surface extending in the horizontal direction, and the outer circumferential surface is axially oriented. The pipe holder 6 and the pipe 7 through which the refrigerant flows are provided. The combustion gas from the burner 8 flows horizontally to the inner surface of the cylinder in the horizontal direction, and the horizontal pipe is sent by the refrigerant carrier 4. It heats the refrigerant flowing inside 7. A temperature detector 9 is attached to the surface between the pipe holding portions 6 and controls so as to stop heating when the temperature of the refrigerant rises abnormally.

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

[0004]

In order to reduce the running cost during heating operation, it is effective to transfer heat without power by eliminating external power for transferring the refrigerant. 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, in the above-mentioned conventional structure, the refrigerant flows in the pipe 7 extending in the horizontal direction, so that the gas component of the refrigerant which is heated and is in the gas-liquid two-phase mixed state does not flow smoothly toward the outlet, so that the refrigerant stagnates. Occurs, and local abnormal overheating is generated, and since the combustion chamber and the heat exchange section are integrated, the heat exchange amount becomes uneven due to the combustion state, resulting in local overheating, thermal decomposition of the refrigerant, abnormal temperature rise of equipment, etc. There was a problem in the reliability performance of the equipment.

Further, when the temperature of the refrigerant rises abnormally, after the latent heat of the refrigerant changes, the temperature of the refrigerant rapidly rises due to a change of sensible heat, so that the response due to the heat capacity of the temperature detector is delayed, and the refrigerant overheats. There was a problem with the reliability of the equipment due to thermal decomposition, deterioration of performance and corrosion.

The present invention is intended to solve the above-mentioned problems, in which the natural circulation cycle of a refrigerant heater heated by a burner or the like is smoothly circulated by enhancing the natural circulation force by rising bubbles.
In addition to more efficient heat transfer to improve thermal efficiency,
This guides the hot combustion gas from the combustion chamber to the heat exchange section uniformly to maintain the uniform circulation of the refrigerant so that the thermal decomposition of the refrigerant does not occur.In addition, when the refrigerant heater runs out of refrigerant, the refrigerant is immediately overheated. The purpose is to detect equipment and protect equipment and normalize system operation.

[0008]

In order to achieve the above object, the present invention has a combustion chamber provided in communication with a burner connected to a fuel supply device and a combustion gas outlet of the combustion chamber. A high temperature gas passage, a large number of fins closely attached to the outer peripheral heat transfer partition of the high temperature gas passage, and a refrigerant passage member integrated with the outer peripheral heat transfer partition forming the outer wall of the high temperature gas passage,
The heat transfer fitting is provided in close contact with the outer peripheral heat transfer partition of the high temperature gas passage, and the temperature detecting means is provided in the refrigerant passage member facing the heat transfer fitting.

[0009]

According to the present invention, the combustion gas ejected from the combustion gas outlet provided in communication with the combustion chamber in the natural circulation cycle of the refrigerant heater heated by the burner or the like is brought into close contact with the heat transfer partition wall on the outer periphery. Between the large number of heat transfer fins and the high temperature gas passage, the temperature and flow of the combustion gas in the heat exchanger can be made uniform, while the refrigerant flow is divided into the respective refrigerant passages of the refrigerant passage member, It receives heat in the middle of this refrigerant passage and gasifies it, uniformly heats each part of the refrigerant passage member and circulates the refrigerant smoothly, and also ensures non-powered heat transfer without locally overheating the refrigerant to thermally decompose the refrigerant. Does not happen. Then, the heat transfer fitting closely attached to the outer peripheral heat transfer partition of the high-temperature gas passage, and the temperature detection means provided in the refrigerant passage member facing the heat transfer fitting, the refrigerant heater, when the refrigerant is insufficient, the refrigerant, When it overheats, this is immediately detected to protect the equipment and normalize the system operation.

During operation, the heat of the high temperature combustion gas is received by the heat transfer fins and the heat transfer metal fittings, and is transferred from the outer peripheral heat transfer partition to the refrigerant passage member to heat the refrigerant. Since the refrigerant in the refrigerant passage receives heat, a part of the refrigerant changes its latent heat to vaporize, so that it is always constant according to the pressure of the refrigerant. The temperature detecting means receives heat from the heat transfer fittings and radiates the heat to the refrigerant passage member to maintain a constant temperature. When the filling amount decreases or the circulation amount decreases, such as the refrigerant leaking to the outside, the temperature of the refrigerant sharply rises due to the latent heat change and the sensible heat change. Therefore, the amount of heat radiated to the refrigerant passage member of the temperature detecting means is sharply reduced, and the amount of heat from the heat transfer metal fitting is not changed, so that the temperature of the temperature detecting means rises rapidly and the temperature detecting means operates without a response delay.

Therefore, when the refrigerant overheats due to lack of refrigerant in the refrigerant heater, the temperature of the temperature detecting means can immediately detect the temperature, normalize the protection of the equipment and the operation of the system, and the thermal decomposition and deterioration of the refrigerant. The system can be made highly reliable without any occurrence.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 2, 10 is a combustion chamber provided in communication with a burner 8 connected to a fuel supply device, 11 is a heat transfer partition, and 12 is a high temperature gas passage, which is in close contact with the heat transfer partition 11. It has a combustion gas outlet 13 and an exhaust passage 14 which are provided in communication with the combustion chamber 10. Reference numeral 15 denotes a refrigerant passage member that is thermally connected to the outer surface of the heat transfer partition wall 11, and has a large number of vertical passages 16. Reference numeral 17 is an inlet header pipe provided at the lower end of the refrigerant passage member 16, and 18 is the refrigerant passage member 1.
6 is an outlet header pipe provided at the upper end of 6, and is connected with an inlet pipe 19 and an outlet pipe 20, respectively, and is connected to the refrigerant circuit by each of them, and the other end of the inlet header pipe 17 is bent downward and is an oil drain pipe. 21 is provided. The inlet header pipe 17 and the outlet header pipe 18 are each a vertical passage 1
6 communicate with each other. Reference numeral 22 is a heat transfer fin provided inside the heat transfer partition wall 11 so as to be in thermal contact therewith, and a plurality of heat transfer fins are provided. The combustion chamber 10 is provided with a heat insulating material 23 that covers the entire outer surface of the combustion chamber 10 that is not in contact with the hot gas passage 12.
A part of the outer peripheral heat transfer partition wall 11 of the high-temperature gas passage 12 is provided with a heat transfer metal fitting 24 in close contact with the heat transfer metal partition 11, and the temperature of the refrigerant passage member 15 facing the heat transfer metal fitting 24 is increased as a temperature detecting means. The thermistor 25 is attached. In this embodiment, the heat transfer fitting 24 and the heat transfer fin 2
2. The heat transfer partition wall 11 is made of aluminum, and the heat transfer metal fitting 24 is fitted to the heat transfer fins 22 and brazed to the heat transfer partition wall 11 so as to be in close contact with the heat transfer partition wall 11 and the heat transfer metal fitting 24.
Is provided. A hole that penetrates through the heat transfer metal fitting 24 and the heat transfer partition wall 11 and reaches the vicinity of the refrigerant passage 16 of the refrigerant passage member 15 is provided at substantially the center of the heat transfer metal fitting 24, and the temperature thermistor 25 is coated with a heat conductive material. Insert it and hold it with the fixture 26,
The temperature sensitive portion of the temperature thermistor 25 is located at the tip and is located near the refrigerant passage 16. Reference numeral 27 is a controller that controls the system by the detection output of the temperature thermistor 24. 29 is an exhaust pipe.

In the above construction, 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 is separated into upper and lower high temperature gases. It passes through the passage between the passage 12 and the heat transfer fin 22, and flows from the upper and lower exhaust passages 14 as shown by arrows to the exhaust pipe 29. On the other hand, the liquid refrigerant that has passed through the refrigerant inlet pipe 19 and entered the inlet header pipe 17 has a larger number of vertical refrigerant passages 1 than the lower portion of the refrigerant passage member 15.
6, the heat is transferred from the combustion gas to the refrigerant passage member 15 by the heat transfer fins 22 from the combustion gas flowing in the high temperature gas passage 12, and the refrigerant in the refrigerant passage 16 in the vertical direction of the refrigerant passage member 15 is transferred. Is sufficiently heated from the lower part near the inlet header 17. 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. Due to the buoyancy effect, the generated bubbles rise upward from below in the refrigerant passage 16 provided in the vertical direction. In particular, combustion gas is used in the combustion chamber 10.
Since the heat is transferred to the refrigerant in the high temperature gas passage 12 after exiting the combustion gas outlet 13 from the combustion gas outlet 13, the temperature and flow of the combustion gas become uniform, and each part of the refrigerant passage member can be uniformly heated to evaporate the refrigerant smoothly and uniformly, and The refrigerant is not locally overheated and the non-powered heat transfer is surely performed so that the refrigerant is not thermally decomposed. Then, by uniform heating, the flow rate of each of the refrigerant passages 16 becomes uniform and the resistance is reduced as a whole, and the bubble ascending force is strengthened and the natural circulation force is strengthened to generate a bubble pump action for sending the refrigerant to the upper part. Further, the heat transfer partition walls 11 other than the heat transfer fins 22 provided on the upper and lower portions of the refrigerant passage 16 are also provided.
The entire surface also becomes a heat transfer area and efficiently absorbs heat from the heating fluid flowing through the high temperature gas passage 12 to further heat the gas-liquid two-phase refrigerant in the refrigerant passage 16 to further increase the natural circulation force.
The refrigerant reaching the upper end of the refrigerant passage 16 has the outlet header pipe 18
To the radiator (not shown) from the refrigerant outlet pipe 20.

Further, a double wall structure is formed by an outer peripheral heat transfer partition wall 11 which forms the outer wall by forming the inner wall of the high temperature gas passage 12 by the combustion chamber 10 and a refrigerant passage member 15 in close contact with the outer peripheral heat transfer partition wall 11. As a result, heat is transferred from the inner wall to the refrigerant passage 16 through the heat transfer fins 22, so that the heat transfer efficiency is increased and the leakage of the refrigerant to the combustion gas portion is prevented by the double wall structure constituted by the refrigerant passage member 15 having the multi-hole pipe structure. And high temperature combustion chamber 1
Since 0 and the refrigerant passage 16 are completely separated by the high temperature gas passage 12, the refrigerant is not thermally decomposed or deteriorated due to local overheating, so that the system has high reliability. Hot gas passage 1 of combustion chamber 10
The remaining outer surface not in contact with 2 is 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 22 are formed by bending a strip-shaped aluminum plate in a wavy shape or by an aluminum extruded material. In addition, the heat transfer partition wall 11 is made of an aluminum core material, and a brazing sheet is preliminarily clad with a brazing material. This material is used as a brazing sheet. A heat exchanger having excellent heat transfer performance without contact heat resistance, which is assembled by using a heat transfer fin 22 made of aluminum and a coolant passage member 16 of a multi-hole flat extrusion tube made of aluminum, and at the same time can be thermally connected by integrally brazing Can be put to practical use at a low cost and at a low cost.

During operation, the heat of the combustion gas flowing through the hot gas passage 12 is received by the heat transfer fins 22 as well as the heat transfer metal fittings 24. This heat is transferred from the outer peripheral heat transfer partition wall 20 to the refrigerant passage member 1
Heat is transferred to 5 to heat the refrigerant. Since the refrigerant in the refrigerant passage 16 receives heat and a part thereof is vaporized and changes in latent heat, the temperature is always constant according to the pressure of the refrigerant. Since a temperature thermistor 25 is provided as a temperature detecting means in the refrigerant passage member 15 facing the heat transfer fitting 24, the temperature detecting means 25 is
It receives heat from the heat transfer metal fitting 24 and radiates it to the refrigerant passage member 15 to maintain a constant temperature. Therefore, the temperature thermistor 2
Since the portion of No. 5 near the conductive metal fitting 24 is kept higher than the temperature of the thermistor, it is possible to prevent the response delay due to the heat capacity of the temperature thermistor 25. When the filling amount is reduced or the circulation amount is reduced, such as when the refrigerant leaks to the outside, the temperature rises rapidly when the refrigerant changes its latent heat and then its sensible heat. Therefore, the amount of heat radiated to the refrigerant passage member 15 of the temperature detecting means 25 decreases sharply, while the amount of heat from the heat transfer fins 22 does not change, the temperature of the temperature detecting means 25 increases rapidly and is detected without a response delay and controlled. The device 27 operates.

Therefore, when the refrigerant is overheated due to a shortage of the refrigerant in the refrigerant heater, the temperature of the temperature detecting means 25 can immediately detect the temperature, normalize the protection of the equipment and the operation of the system, and the thermal decomposition of the refrigerant. , A highly reliable system without deterioration.

When much oil is accumulated, its viscosity and low heat conduction impede vaporization and circulation of the refrigerant. In this case, as in the case where the amount of the refrigerant decreases, the amount of the refrigerant flowing in the refrigerant passage 16 decreases, and when the amount of the refrigerant decreases less than a predetermined amount, all of the gas is vaporized (gasified) and the temperature rises due to sensible heat. The temperature of a certain temperature thermistor 25 rises. Based on this detection output, the oil drain pipe 2 connected to the inlet header 17 provided at the bottom of the refrigerant passage 16 which is the refrigerant passage member 15.
It is a highly reliable system in which the oil is reliably removed from the heater by discharging from No. 1 and the uniform circulation of the refrigerant is maintained so that the refrigerant is not thermally decomposed due to local overheating.

FIG. 3 shows another embodiment. The same parts as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted. Different parts will be mainly described. The heat transfer fitting 24 is provided with a gas passage 28 whose both ends communicate with a high temperature gas passage through which combustion gas passes. During operation, the heat of the combustion gas flowing through the high-temperature gas passage 12 flows through the gas passage 28 together with the outer periphery of the heat transfer fitting 24, and receives the heat. Therefore, the heat transfer fitting 24 receives a large amount of heat from the combustion gas and is in equilibrium in a state where the amount of heat radiated to the refrigerant is also large, so that the temperature gradient between the heat transfer fitting 24 and the refrigerant passage 16 becomes large. Therefore, when the refrigerant is overheated, the temperature of the temperature detecting means 25 is kept higher than that of the heat transfer metal fitting 24 and flows into the refrigerant passage 16 to stop the flow of a large amount of heat in equilibrium. The temperature of the temperature detecting means 25 rises quickly, and the temperature detecting means 25 can detect this immediately and normalize the protection of the equipment and the operation of the system, resulting in a highly reliable system without thermal decomposition and deterioration of the refrigerant.

According to the structure of this embodiment, the heat transfer metal fittings 24 that are in close contact with the outer peripheral heat transfer partition wall 11 of the high temperature gas passage 12,
By providing the temperature detecting means in the refrigerant passage member 15 that opposes the heat transfer metal fitting, when the refrigerant is overheated due to lack of the refrigerant in the refrigerant heater or the like, the temporal response of the temperature detecting means. Is improved, and this is immediately detected to protect the equipment and normalize the operation of the system.

[0022]

As described above, in the heat exchanger of the present invention, the combustion chamber provided in communication with the burner connected to the fuel supply device and the high temperature gas provided in communication with the combustion gas outlet of the combustion chamber. A passage, a large number of fins closely attached to the outer peripheral heat transfer partition of the high temperature gas passage, and the inner wall of the high temperature gas passage formed of the combustion chamber, together with the outer peripheral heat transfer partition forming the outer wall of the high temperature gas passage. Since the refrigerant passage member, the heat transfer metal fitting in close contact with the outer peripheral heat transfer partition of the high temperature gas passage, and the temperature detecting means provided in the refrigerant passage member facing the heat transfer metal fitting are as follows: Expected to be effective.

(1) In the natural circulation cycle of the refrigerant heater heated by a burner or the like, the temperature and flow of the combustion gas can be made uniform, so that each part of the refrigerant passage member is uniformly heated and the refrigerant is circulated smoothly, and Non-powered heat transfer is reliably performed without locally heating the refrigerant, and thermal decomposition does not occur. When the refrigerant heater runs short of the refrigerant, for example, when the refrigerant is heated, it can be immediately detected without delay in response to normalize the protection of the device and the operation of the system, and the thermal decomposition and deterioration of the refrigerant can be prevented.

(2) Non-powered heat transfer is possible due to the bubble pump action by the rising bubble flow, and heating with low running cost is possible.

(3) Since it is a double wall in which the refrigerant passage member is integrally formed with the outer peripheral heat transfer partition, the leakage of the refrigerant to the combustion gas portion is prevented and the high temperature combustion chamber and the refrigerant passage are completely formed by the high temperature gas passage. Since it is separated, thermal decomposition and deterioration of the refrigerant due to local overheating does not occur, or it is a highly reliable system by preventing abnormal temperature rise of the equipment, it has a simple configuration and can maintain airtightness, and exhaust gas does not leak, refrigerant leaked Also in this case, the refrigerant gas does not come into direct contact with the fire, and the safety can be improved.

(4) By providing the heat transfer fitting with the gas passage through which the combustion gas passes, when the refrigerant is overheated, the temperature of the temperature detecting means is such that the temperature of the heat transfer fitting is kept higher and flows into the refrigerant passage. Since a large amount of heat in equilibrium stops the flow, temperature detection means can immediately detect this and normalize the protection of equipment and system operation, thermal decomposition of refrigerant,
It can be done without deterioration.

(5) Generally, when a large amount of oil is accumulated in the heater, its viscosity and low heat conduction hinder vaporization and circulation of the refrigerant. Then, as in the case where the amount of refrigerant is reduced, when the refrigerant flow rate is less than a predetermined value, all is vaporized (gasified) and a temperature rise due to sensible heat occurs. Therefore, in the present invention, the temperature of the temperature detecting means rises, and this detection output Since it is discharged from the oil drain pipe connected to the inlet header at the bottom of the refrigerant passage member of the refrigerant passage member, oil is reliably removed from the heater to maintain uniform circulation of the refrigerant, causing thermal decomposition of the refrigerant due to local overheating. Moreover, it is possible to prevent deterioration of oil at high temperature.

[Brief description of drawings]

FIG. 1 is a sectional view of a heat exchanger according to an embodiment of the present invention.

FIG. 2 is a sectional view of the refrigerant passage member portion.

FIG. 3 is a partial sectional view of a heat exchanger according to another embodiment.

FIG. 4 is a circuit configuration diagram of a conventional refrigerant heater.

FIG. 5 is an external perspective view of a conventional refrigerant heater.

[Explanation of symbols]

 8 Burner 10 Combustion Chamber 11 Heat Transfer Partition 12 High Temperature Gas Passage 13 Combustion Gas Outlet 14 Exhaust Portion 15 Refrigerant Passage Member 16 Refrigerant Passage 22 Heat Transfer Fin 24 Heat Transfer Metal Fitting 25 Temperature Detection Means 28 Gas Passage

Claims (3)

[Claims] 1. A combustion chamber provided in communication with a burner connected to a fuel supply device, a high temperature gas passage provided in communication with a combustion gas outlet in the combustion chamber, and an outer peripheral heat transfer partition of the high temperature gas passage. A large number of heat transfer fins in close contact with each other, a refrigerant passage member integrated with an outer peripheral heat transfer partition wall forming the outer wall of the high temperature gas passage, and a heat transfer metal fitting in close contact with the outer peripheral heat transfer partition wall located in the high temperature gas passage, A heat exchanger in which temperature detecting means is provided in the refrigerant passage member facing the heat transfer fitting. 2. The heat exchanger according to claim 1, wherein a hole is provided penetrating from the heat transfer metal fitting to the refrigerant passage member facing the heat transfer metal fitting, and the temperature detecting means is inserted into the hole. 3. The heat exchanger according to claim 1, wherein the heat transfer fitting is provided with a gas passage whose both ends communicate with the high temperature gas passage.