JPH11287569A - Refrigerant heater, outdoor machine unit and air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a manufacturing cost for a cylindrical body by eliminating the necessity of providing a half-slit sleeve, such as a conventional outer cylinder, in the cylindrical body and reduce a working cost for fixing a refrigerant pipeline by eliminating the necessity of applying works, such as conventional pipe expanding, caulking and the like. SOLUTION: In a refrigerant heater, provided with a combustion unit, generating combustion gas, an outer cylinder 53, through which the combustion gas is passed along the inner surface of the same, and a refrigerant pipeline 52, provided along the outer surface of an outer cylinder 53, heat exchange is effected between refrigerant, passed through the refrigerant pipeline 52 after liquefied in an indoor heat exchanger, and combustion gas, generated in the combustion unit, to heat and evaporate the refrigerant upon heating operation in an air conditioner. In such a refrigerant heater, the refrigerant pipeline 52 is provided along the side surface of the outer cylinder 53 under meandering condition and is bound to a pipeline fixing cover 55, attached to the circumference of the outer cylinder 53, to contact the same to the side surface of the outer cylinder 53 by a pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant heating type air conditioner for heating a liquid refrigerant and circulating it as a gas refrigerant during a heating operation.

[0002]

2. Description of the Related Art In recent years, an air conditioner employing a refrigerant heating system has been developed in addition to an air conditioner which performs heating using a heat pump. Refrigerant-heated air conditioners include an indoor heat exchanger, a compressor, an outdoor heat exchanger, an expansion valve, etc., as well as a refrigerant heater that heats and evaporates liquid refrigerant instead of the outdoor heat exchanger during heating operation. Is provided in an outdoor unit, and a fuel such as kerosene or propane gas is burned in a refrigerant heater to generate a combustion gas, and the combustion gas is further heated to vaporize a liquid refrigerant.

The refrigerant-heated air conditioner has the following advantages over a heat pump type air conditioner and a fan heater. (1) In a heat pump type air conditioner, heat exchange in an outdoor heat exchanger (heats a liquid refrigerant with outdoor air to vaporize and evaporate the liquid refrigerant) particularly when the outdoor temperature becomes extremely low in a cold region or the like. Is not sufficiently performed, and a desired heating state may not be realized. In contrast, in the air conditioner of the refrigerant heating type, the liquid refrigerant is forcibly heated and vaporized by the refrigerant heater, so that a stable heating operation is performed without being affected by the outdoor temperature to achieve a desired heating state. can do. (2) In a heat pump type air conditioner, when frost adheres to the outdoor heat exchanger and heat exchange cannot be performed sufficiently, the heating operation is stopped and the cooling operation is temporarily performed to perform the outdoor heat exchanger. Since the so-called defrosting operation of removing frost by radiating heat is performed every several hours, comfort may be impaired. On the other hand, in the air conditioner of the refrigerant heating type, it is not necessary to perform the defrost operation, so that a stable heating operation can always be performed even in a low-temperature and high-humidity state, and a desired heating state can be realized. (3) In the fan heater, since the combustion gas is exhausted into the room, it is necessary to periodically ventilate the room, and the heating efficiency is poor. On the other hand, in the air conditioner of the refrigerant heating type, the refrigerant heater is housed in the outdoor unit, and the combustion gas is discharged indoors, so that the frequency of ventilation is less, and the improvement of the heating efficiency can be expected.

Here, the refrigerant heater will be described. The refrigerant heater takes in outdoor air and supplies it to the downstream combustion section, and the combustion that mixes and burns the air and fuel supplied from the supply section to generate high-temperature combustion gas And a heat exchange unit for heating the liquid refrigerant by the combustion gas generated in the combustion unit.

FIG. 9 shows the heat exchange section. In the heat exchange section, a refrigerant pipe 2 for circulating a high-temperature and high-pressure liquid refrigerant liquefied in the indoor heat exchanger and sending it to the compressor is provided on a side surface of the heat exchange section main body 1 heated by the combustion gas. It is configured. The heat exchange unit main body 1 is disposed inside the outer cylinder 3 with a sufficient gap provided between the bottomed cylindrical outer cylinder 3 to which the refrigerant pipe 2 is attached and the inner surface of the outer cylinder 3. And a bottomed cylindrical inner cylinder 4. The outer cylinder 3 has an open end facing the combustion portion, and is arranged inside the outer cylinder 3 with the open end of the inner cylinder 4 opened.

The outer cylinder 3 is an integrally molded product of aluminum, and a plurality of fins 3a are provided on the inner surface along the longitudinal direction for securing a large heat receiving area and effectively absorbing the heat of the combustion gas. . The refrigerant pipe 2 is a copper pipe, and is provided in a meandering manner so as to reciprocate in the longitudinal direction of the outer cylinder 3 in order to secure a larger contact area with the heat exchange unit main body 1.

As shown in FIG. 10, the refrigerant pipe 2 is fitted inside a half sleeve 3b integrally formed along the longitudinal direction on the side surface of the outer cylinder 3 to expand the pipe itself from the inside. The half sleeve 3b is fixed to the outer cylinder 3 by a method such as caulking for deforming the half sleeve 3b inward.

[0008]

The following problems have been pointed out in the conventional refrigerant heater. (1) The method of fixing the refrigerant pipe by expanding the pipe is excellent in the adhesion between the outer cylinder and the refrigerant pipe, but it is very difficult to expand the diameter of the pipe, and the processing cost increases. (2) In the method of fixing the refrigerant pipe by caulking, it is necessary to secure a predetermined inner diameter without crushing the refrigerant pipe, and the processing cost is increased, though not as much as expansion.

The present invention has been made in view of the above circumstances, and has as its object to reduce the manufacturing cost of a refrigerant heater by reducing the manufacturing cost of an outer cylinder and the processing cost required for fixing a refrigerant pipe. I have.

[0010]

According to the present invention, the following configuration is employed to solve the above-mentioned problems. That is, the refrigerant heater according to claim 1 is a combustion unit that burns air and fuel taken from outside to generate a combustion gas,
A cylindrical body disposed in communication with the combustion section and through which combustion gas flows along an inner surface, and a refrigerant pipe attached to an outer surface of the cylindrical body, and indoor heat exchange during a heating operation in the air conditioner. A refrigerant heater that liquefies the refrigerant and then exchanges heat between the refrigerant passed through the refrigerant pipe and the combustion gas generated in the combustion section, heats and vaporizes the refrigerant, and sends it to the compressor. Further, there is provided a pipe fixing means for restraining the refrigerant pipe in a state of being pressed against a side surface of the cylindrical body.

In this refrigerant heater, the refrigerant pipe is
By being restrained by the pipe fixing means, the cylindrical body is deformed in a direction in which the cylindrical body is tightened from the periphery, and is pressed against the side surface of the cylindrical body. This eliminates the need to provide a half sleeve as in the conventional outer cylinder on the cylindrical body, and reduces the manufacturing cost of the cylindrical body. In addition, there is no need to perform processing such as pipe expansion or swaging, and processing costs for fixing the refrigerant pipes are reduced.

According to a second aspect of the present invention, in the refrigerant heater, the pipe fixing means also serves as a heat shield cover for suppressing heat dissipation from the cylindrical body.

In this refrigerant heater, since the pipe fixing means for pressing the refrigerant pipe against the side surface of the cylindrical body also serves as a heat shield cover, the thermal efficiency is improved, and the heat exchanger can be downsized to reduce the manufacturing cost. It becomes possible.

According to a third aspect of the present invention, in the refrigerant heater, the refrigerant pipe is provided in a meandering manner so as to reciprocate in a circumferential direction with respect to a side surface of the cylindrical body. .

In this refrigerant heater, the refrigerant pipe is bent beforehand in a meandering state along a plane, and then rounded to the diameter of the cylinder or a diameter larger than that, and the pipe is fixed by the pipe fixing means. Since it is pressed against the side surface, processing and assembly become easy.

According to a fourth aspect of the present invention, in the refrigerant heater, the refrigerant pipe is provided in a meandering manner so as to reciprocate in a longitudinal direction with respect to a side surface of the cylindrical body. .

In this refrigerant heater, the refrigerant pipe is bent beforehand in a meandering state along a plane, and then rounded to the diameter of the cylinder or a diameter larger than that, and the pipe is fixed by the pipe fixing means. Since it is pressed against the side surface, processing and assembly become easy.

According to a fifth aspect of the present invention, there is provided an outdoor unit, wherein the refrigerant heater according to the first, second, third or fourth aspect and the compression for sucking and compressing the refrigerant vaporized in the refrigerant heater and sending it to the indoor heat exchanger. Machine.

In this outdoor unit, the manufacturing cost of the outdoor unit itself can be reduced by providing the refrigerant heater whose cost is reduced.

The outdoor unit according to a sixth aspect is characterized in that either the refrigerant heater or the outdoor heat exchanger is selectively operated to heat and vaporize the refrigerant liquefied in the indoor heat exchanger. Is what you do.

In this outdoor unit, even if the refrigerant heating operation has to be stopped due to running out of fuel or the like,
By switching to heat pump operation and operating it, heating can be continued.

According to a seventh aspect of the present invention, there is provided an air conditioner which heats indoor air by condensing and liquefying the refrigerant delivered from the outdoor unit during a heating operation. And an indoor unit having an exchanger.

In this air conditioner, the production cost of the air conditioner itself can be reduced by providing the outdoor unit whose production cost is reduced.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a refrigerant heater, an outdoor unit and an air conditioner according to the present invention will be described with reference to FIGS. The air conditioner shown in FIG. 1 includes an indoor unit 10 and an outdoor unit 20. The indoor unit 10 has an indoor heat exchanger that evaporates and evaporates a low-temperature and low-pressure liquid refrigerant to remove heat from indoor air during a cooling operation, and condenses and liquefies a high-temperature and high-pressure gas refrigerant during a heating operation to warm indoor air. 11 are provided.

The outdoor unit 20 includes an outdoor heat exchanger 21 for condensing and liquefying a high-temperature and high-pressure gas refrigerant during cooling operation and radiating heat to outdoor air, and either the indoor heat exchanger 11 or the outdoor heat exchanger 21. A compressor 22 that compresses a gas refrigerant sucked from the compressor and discharges the refrigerant as a high-temperature and high-pressure gas refrigerant, an accumulator 23 that stores a liquid component contained in the gas refrigerant flowing into the compressor 22, and a compressor 22 that is compressed by the compressor 22 A four-way valve 24 for selectively sending a high-temperature and high-pressure gas refrigerant to either the indoor heat exchanger 11 or the outdoor heat exchanger 21
And a capillary tube 25 that decompresses and expands the high-temperature and high-pressure liquid refrigerant sent from the outdoor heat exchanger 21 during the cooling operation to make it a low-temperature and low-pressure liquid refrigerant, and heats the high-temperature and high-pressure liquid refrigerant during the heating operation. And a refrigerant heater 26 which is a high-temperature and high-pressure gas refrigerant.

During the heating operation, the refrigerant heater 26 is supplied from the fuel tank 27 provided adjacent to the outdoor unit 20 to the constant oil level unit 2.
The fuel such as kerosene and propane gas supplied by the operation of the electromagnetic pump 29 through the fuel gas 8 generates high-temperature combustion gas, and the high-temperature and high-pressure liquid refrigerant liquefied in the indoor heat exchanger 11 by the combustion gas Is heated to obtain a high-temperature and high-pressure gas refrigerant.

[0027] As shown in FIG.
An air supply unit 30 that takes in outdoor air and supplies the air to a subsequent combustion unit, a combustion unit 40 that mixes the air supplied from the air supply unit 30 with a fuel such as kerosene or propane gas, and burns the mixture.
A heat exchange unit 50 is provided for heating the liquid refrigerant by the combustion gas generated in the combustion unit 40.

The air supply section 30 includes a cylindrical casing 31 in which one or a plurality of fans 32 and a drive motor 33 for rotating the fans 32 are housed. An air intake 34 for taking in outdoor air is provided on a side surface of the casing 31. The air taken into the casing 31 by the rotation of the fan 32 flows along the side surface of the drive motor 33, and is supplied to the combustion section 40 from a communication port 35 provided in the casing 31.

The combustion section 40 is configured by housing a combustion cylinder 42 having a bottomed cylindrical shape in a cylindrical casing 41 fixed to one end surface of the casing 31 close to the drive motor 33. As shown in FIG. 3, the casing 41 has fins 41 a which pivot around the combustion cylinder 42 and form a flow of air flowing from one side surface which forms an obtuse angle with respect to an air inflow hole 42 a to be described later. It is provided adjacent to 35.

On the side wall of the combustion cylinder 42, an air inlet 42a through which a part of the air supplied from the air supply section 30 (hereinafter referred to as primary air) flows into the interior of the combustion cylinder 42 is provided. The side wall of the cylinder 42 is opened in parallel with the tangential direction. The opening 42b of the air inflow hole 42a is
Has a round shape which is wide on the outer wall surface side and gradually contracts while forming a curved surface toward the inside.

A fuel supply nozzle 43 for injecting fuel toward the inside of the combustion cylinder 42 is inserted into the air inflow hole 42a. The fuel supply nozzle 43 is connected to the electromagnetic pump 29 described above.
Are arranged in parallel with the direction in which the air inflow holes 42a are arranged and with a gap provided between the air inflow holes 42a and the inner surface of the air inflow holes 42a.

Further, on the side wall of the combustion cylinder 42, the combustion cylinder 4
A plurality of auxiliary air inflow holes 42c for allowing air to flow into the interior of the vehicle 2 are provided. These auxiliary air inflow holes 42c are provided in a portion of the inner wall surface of the combustion cylinder 42 where the fuel injected from the fuel supply nozzle 43 collides, and are circumferentially spaced along the side wall of the combustion cylinder 42, In addition, each is provided in a direction parallel to a tangent to the side wall of the combustion cylinder 42.

The air supplied from the air supply section 30 flows into the combustion cylinder 42 through a gap provided between the air inlet 42a and the fuel supply nozzle 43 and the auxiliary air inlet 42c, and the air is supplied. The air flowing in from the inflow holes 42a flows in one direction along the inner wall surface of the combustion tube 42 to form a swirl flow, and the air flowing in through the auxiliary air inflow holes 42c merges with the swirl flow to increase the flow force. Has been strengthened.

The combustion cylinder 42 is provided on the side wall of the combustion cylinder 42.
A heater 44 for heating and evaporating and evaporating the fuel supplied to the inside of the chamber is embedded so as to surround a vaporization chamber S1 described later. The fuel supply nozzle 43 is disposed in the same cross section as the heater 44, and the heater 44 is embedded at a position facing the fuel supply nozzle 43 in front of the injection direction.

A cylindrical projection 45 is provided upright at the center of the inner bottom surface of the combustion cylinder 42. At the center of the protruding portion 45, an air passage 45a through which the remaining air (hereinafter, referred to as secondary air) supplied from the air supply portion 30 flows toward a combustion chamber S2 described later is provided. Opened in the axial direction. An inner surface of the air passage 45 a is provided with a tapered surface 45 c which is narrow at an opening 45 b located on the outer bottom surface of the combustion cylinder 42 and gradually increases toward the tip of the projection 45. The secondary air supplied from the air supply unit 30 flows into the combustion chamber S2 through the air passage 45a.

Inside the combustion cylinder 42, a vaporization chamber partition 46 which forms a vaporization chamber S1 with the inner bottom surface is installed horizontally with respect to the bottom surface of the combustion cylinder 42. The vaporization chamber partition wall 46 is formed in a circular shape in accordance with the space inside the combustion cylinder 42, and at the center thereof is provided a cylindrical part 46 a formed in a state where a gap is provided between the side wall of the projection 45. The gap provided between the side surface of the projection 45 and the cylindrical portion 46a forms a flow path for allowing the premixed gas to flow from the vaporization chamber S1 to the combustion chamber S2. The primary air that has flowed into the combustion cylinder 42 is
In 1, it is mixed with fuel to become a premixed gas, and the protrusion 4
5, and flows out of the vaporizing chamber S1 through a gap with the cylindrical portion 46a.

Further, the interior of the combustion cylinder 42 is divided into a vaporization chamber S1 and a combustion chamber S2 by a burner partition 47 provided with a plurality of flame holes 47a for injecting and burning a premixed gas. The flame holes 47a are arranged at regular intervals along the circumferential direction of the combustion cylinder 42. The premixed gas flowing out of the vaporization chamber S1 flows so as to diffuse outward along the inner surface of the recess 47b and is ejected from each of the flame holes 47a.

An ignition plug 49 is provided in the combustion chamber S2 for igniting the premixed gas ejected from the flame hole 47a. The premixed gas injected into the combustion chamber S2 is ignited by the ignition plug 49, burns together with the secondary air, becomes high-temperature combustion gas, and flows into the heat exchange section 50.

The heat exchanging section 50 includes a heat exchanging section main body 51 fixed to an open end of the casing 41b on the combustion gas outflow direction side.
A refrigerant pipe 5 that circulates a high-temperature and high-pressure liquid refrigerant liquefied in the indoor heat exchanger 11 and sends out the refrigerant to the compressor 22
2 is provided in a bent state.

The heat exchange section main body 51 is provided with a sufficient gap between the bottomed cylindrical outer cylinder (cylindrical body) 53 to which the refrigerant pipe 52 is attached and the inner surface of the outer cylinder 53. A bottomed cylindrical inner cylinder 54 disposed inside the cylinder 53, with the open end of the outer cylinder 53 facing the combustion section 40, and the open end of the inner cylinder 54 opened inside the outer cylinder 53. It is arranged in the state where it was done. A tubular pipe fixing cover (pipe fixing means) 55 also serving as a heat shield cover is placed over the refrigerant pipe 52 provided around the outer cylinder 53, and a heat exchange unit main body is provided on the bottom surface of the outer cylinder 53. An exhaust pipe 56 for discharging the combustion gas flowing inside 51 to the outside is connected.

A plurality of grooves 53a are formed on the inner surface of the outer cylinder 53 along the longitudinal direction. The groove 53a is formed over the entire circumference on the inner surface of the outer cylinder 53.
Are provided with irregularities on the inner surface. Inner cylinder 54
Is provided with a spiral plate 54a spirally formed in the longitudinal direction.

In order to secure a larger contact area with the heat exchange section main body 51, the refrigerant pipe 52 is, as shown in FIG.
It is attached in a meandering manner so as to reciprocate in the circumferential direction with respect to the side surface of the outer cylinder 53.

The pipe fixing cover 55 has a shape in which a part of the side face is cut along the longitudinal direction, and a small hole is provided in the cut edge 55a which is turned outward. As shown in FIG. 5, the refrigerant pipe 52 is restrained by the pipe fixing cover 55, and is pressed against the side surface of the outer cylinder 53 by fastening the stopper 55 b such as a nut.

The combustion gas that has flowed into the heat exchange section 50 flows into the inner cylinder 54 and makes a U-turn on the bottom surface.
When it returns to the opening end of the above, a U-turn is made again, and a turbulent state in which the flow is slow is established. Then, heat is exchanged with the liquid refrigerant flowing toward the bottom surface of the outer cylinder 53 while rotating between the outer cylinder 53 and the inner cylinder 54 along the spiral plate 54 a and flowing through the refrigerant pipe 52. In this process, the temperature of the combustion gas becomes 1
The temperature is lowered from 200 to 1300 ° C. to about 200 ° C., and finally discharged from the exhaust pipe 56 to the outside.

In the air conditioner configured as described above,
During the cooling operation, the four-way valve 24 includes the compressor 22 and the outdoor heat exchanger 21, the indoor heat exchanger 11 and the accumulator 23,
Are connected to each other. From this state, the high-temperature and high-pressure gas refrigerant discharged from the compressor 22 is sent to the outdoor heat exchanger 21.

The high-temperature and high-pressure gas refrigerant is condensed and liquefied in the outdoor heat exchanger 21 and radiates heat to outdoor air to become a high-temperature and high-pressure liquid refrigerant. Further, the high-temperature and high-pressure liquid refrigerant is reduced in pressure in the process of passing through the capillary tube 25, becomes a low-temperature and low-pressure liquid refrigerant, and is sent to the indoor unit 10 via the check valve 60.

The low-temperature and low-pressure liquid refrigerant sent to the indoor unit 10 is evaporated and vaporized in the indoor heat exchanger 11, cools by removing heat from the indoor air, and becomes a low-temperature and low-pressure gas refrigerant. Sent to

The low-temperature and low-pressure gas refrigerant sent to the outdoor unit 20 flows into the accumulator 23 via the four-way valve 24 and the check valve 61, and is sucked into the compressor 21 after the liquid component is separated. The gas refrigerant sucked into the compressor 21 is compressed by the operation of the compressor 21, becomes a high-temperature and high-pressure gas refrigerant, and is sent to the outdoor heat exchanger 21 again.

On the other hand, during the heating operation, the four-way valve 24
Is in a state where the compressor 22 and the indoor heat exchanger 11 are connected, and the outdoor heat exchanger 21 and the accumulator 23 are connected. From this state, the high-temperature and high-pressure gas refrigerant discharged from the compressor 22 is supplied to the indoor heat exchanger 1 of the indoor unit 10.
Sent to 1.

The high-temperature and high-pressure gas medium is condensed and liquefied in the indoor heat exchanger 11 and radiated to indoor air to be heated, and then sent to the outdoor unit 20 as a high-temperature and high-pressure liquid refrigerant.
The high-temperature and high-pressure liquid refrigerant sent to the outdoor unit 20 is prevented from flowing into the outdoor heat exchanger 21 by the check valve 60, but the electromagnetic valve 62 is opened and the refrigerant provided in the refrigerant heater 26 is opened. It flows into the pipe 52.

The liquid refrigerant flowing into the refrigerant pipe 52 exchanges heat with the outer cylinder 53 heated by the heat of the combustion gas, is vaporized, and flows into the accumulator 23 as a high-temperature and high-pressure gas refrigerant. After the liquid components are separated, the compressor 21
Inhaled. The gas refrigerant sucked into the compressor 21 is compressed by the operation of the compressor 21, becomes a high-temperature and high-pressure gas refrigerant, and is sent to the indoor heat exchanger 11 again.

In the air conditioner configured as described above,
When the refrigerant pipe 52 is restricted by the pipe fixing cover 55, the refrigerant pipe is deformed in a direction in which the outer cylinder 53 is tightened from the periphery, and is pressed against the side surface of the outer cylinder 53. For this reason, it is not necessary to provide a half-split sleeve like the conventional outer cylinder in the outer cylinder 53, so that the manufacturing cost of the outer cylinder 53 is reduced, and it is not necessary to perform processing such as conventional pipe expansion and swaging. Since the processing cost for fixing the refrigerant pipe 52 is reduced, the manufacturing cost of the refrigerant heater 26 can be reduced. Further, by reducing the manufacturing cost of the refrigerant heater 26, the outdoor unit 2 having the refrigerant heater 26 can be used.
Further, the manufacturing cost of the air conditioner including the outdoor unit 20 can be reduced.

In the first embodiment, in order to secure a larger contact area with the heat exchange unit main body 51, the refrigerant pipe 52 is meandering so as to reciprocate in the circumferential direction with respect to the side surface of the outer cylinder 53. However, as shown in FIG. 6 or FIG. 7, the refrigerant pipe 52 ′ may be provided in a meandering manner so as to reciprocate in the longitudinal direction with respect to the side surface of the outer cylinder 53. Absent.

Next, a second embodiment of the refrigerant heater, the outdoor unit and the air conditioner according to the present invention will be described with reference to FIG. The components already described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
The air conditioner shown in FIG. 8 has a so-called refrigerant heating type heat pump that can selectively perform either a refrigerant heating operation performed by activating the refrigerant heater 26 or a conventional heat pump operation when performing heating. It is an air conditioner of the combined type.

The air conditioner has an outdoor unit 20
In addition, the capillary tube 70 which decompresses and expands the high-temperature and high-pressure liquid refrigerant sent from the indoor heat exchanger 11 during the heating operation to be a low-temperature and low-pressure liquid refrigerant, and is closed from the outdoor heat exchanger 21 during the cooling operation to be sent out An electromagnetic valve 71 is provided to prevent the flow of the high-temperature and high-pressure liquid refrigerant and to open the high-temperature and high-pressure liquid refrigerant to the capillary tube 70 during the heating operation.

In the air conditioner configured as described above,
Since the solenoid valve 71 is closed during the cooling operation, the first
A cooling cycle similar to that of the air conditioner described in the embodiment is realized.

On the other hand, during the heating operation, for example, when all the fuel in the fuel tank 27 has been consumed,
The electromagnetic valve 62 is closed and the electromagnetic valve 71 is opened, the refrigerant heating operation is stopped, and the heat pump operation is started. That is, the high-temperature and high-pressure gas refrigerant discharged from the compressor 22 is sent to the indoor heat exchanger 11 of the indoor unit 10.

The high-temperature and high-pressure gas refrigerant is condensed and liquefied in the indoor heat exchanger 11, radiates heat to indoor air and is heated, and then is sent to the outdoor unit 20 as a high-temperature and high-pressure liquid refrigerant.
The high-temperature and high-pressure liquid refrigerant sent to the outdoor unit 20 is prevented from flowing into the outdoor heat exchanger 21 by the check valve 60,
The closed electromagnetic valve 62 prevents the refrigerant from flowing into the refrigerant heater 26, but is decompressed in the process of opening the electromagnetic valve 71 and passing through the capillary tube 70, and becomes a low-temperature and low-pressure liquid refrigerant to form an outdoor heat exchanger. 21.

The low-temperature and low-pressure liquid refrigerant is evaporated and vaporized in the outdoor heat exchanger 21 and takes heat from outdoor air to become a low-temperature and low-pressure gas refrigerant, which flows into the accumulator 23 via the four-way valve 24 and the check valve 61. After the liquid component is separated, it is sucked into the compressor 22. The gas refrigerant sucked into the compressor 22 is compressed into a high-temperature and high-pressure gas refrigerant, and is sent to the indoor heat exchanger 11 again. Note that the switching between the refrigerant heating operation and the heat pump operation can be performed not only automatically upon detection of running out of fuel but also artificially as necessary.

According to the air conditioner configured as described above, even if the fuel runs out during the refrigerant heating operation, the heating can be continued by switching to the heat pump operation and operating. Even if the fuel is not exhausted, the operation cost can be reduced by switching between the refrigerant heating operation and the heat pump operation as necessary.

[0061]

As described above, according to the refrigerant heater according to the present invention, the refrigerant pipe is deformed in the direction in which the cylinder is clamped from the periphery by the restriction of the refrigerant pipe by the pipe fixing means, so that the cylinder is formed. Is pressed against the side of This eliminates the need to provide a half sleeve as in the conventional outer cylinder on the cylindrical body, thereby reducing the manufacturing cost of the cylindrical body,
Since there is no need to perform the conventional processing such as pipe expansion and swaging, and the processing cost for fixing the refrigerant pipe is reduced, the manufacturing cost of the refrigerant heater can be reduced.

Further, since the pipe fixing means also serves as a heat-shielding cover for suppressing the diffusion of heat from the cylindrical body, the heat efficiency is improved and the manufacturing cost of the refrigerant heater is reduced by reducing the size of the heat exchanger. Can be reduced.

The refrigerant pipe was previously bent in a meandering state along a plane, then rounded to the diameter of the cylindrical body or larger, and meandered so as to reciprocate in the circumferential direction with respect to the side surface of the cylindrical body. By being attached to the state, processing and assembling are facilitated, whereby the productivity of the refrigerant heater can be improved.

After the refrigerant pipe was bent in a meandering state along a plane in advance, it was rounded to the diameter of the cylindrical body or a diameter larger than that, and meandered back and forth in the longitudinal direction with respect to the side surface of the cylindrical body. By being attached to the state, processing and assembling are facilitated, whereby the productivity of the refrigerant heater can be improved.

According to the outdoor unit of the present invention, the manufacturing cost of the outdoor unit including the refrigerant heater can be reduced by reducing the manufacturing cost of the refrigerant heater.

Further, by selectively operating either the refrigerant heater or the outdoor heat exchanger to heat and vaporize the liquefied refrigerant in the indoor heat exchanger, the refrigerant heating operation is stopped due to running out of fuel or the like. Even in the case where it is unavoidable, heating can be continued by switching to and operating the heat pump operation. Further, even if the fuel is not exhausted, the operation cost can be reduced by switching between the refrigerant heating operation and the heat pump operation as needed.

According to the air conditioner of the present invention, the production cost of the outdoor unit can be reduced, thereby reducing the production cost of the air conditioner itself having the outdoor unit. And a high-performance air conditioner can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a refrigerant heater, an outdoor unit, and an air conditioner according to the present invention.

FIG. 2 is a side sectional view of a refrigerant heater.

FIG. 3 is a side sectional view particularly showing a combustion part in the refrigerant heater shown in FIG. 2;

FIG. 4 is an exploded perspective view particularly showing a heat exchange section of the refrigerant heater shown in FIG.

FIG. 5 is a side view of the heat exchange unit shown in FIG.

FIG. 6 is an exploded perspective view showing another form of the heat exchange section shown in FIG.

FIG. 7 is a side view of the heat exchange unit shown in FIG.

FIG. 8 is a schematic configuration diagram illustrating a second embodiment of a refrigerant heater, an outdoor unit, and an air conditioner according to the present invention.

FIG. 9 is a perspective view of a heat exchange section of a refrigerant heater provided in a conventional refrigerant heating type air conditioner.

FIG. 10 is a cross-sectional view showing a method of fixing a refrigerant pipe in the heat exchange section shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Indoor unit 11 Indoor heat exchanger 20 Outdoor unit 21 Outdoor heat exchanger 26 Refrigerant heater 30 Air supply part 40 Burning part 50 Heat exchange part 51 Heat exchange part main body 52 Refrigerant pipe 53 Outer cylinder (cylindrical body) 54 Inside Pipe 55 Pipe fixing cover (Piping fixing means)

Claims (7)

[Claims] A combustion unit that combusts air and fuel taken from outside to generate a combustion gas; a cylinder disposed in communication with the combustion unit and through which the combustion gas flows along an inner surface; A refrigerant pipe attached to the outer surface of the cylindrical body, between the refrigerant liquefied in the indoor heat exchanger during the heating operation in the air conditioner and then passed through the refrigerant pipe and the combustion gas generated in the combustion section. A refrigerant heater that heat-exchanges, heats and vaporizes the refrigerant, and sends the refrigerant to the compressor, wherein pipe fixing means is provided for restraining the refrigerant pipe in a state of being pressed against the side surface of the cylindrical body. A refrigerant heater characterized in that: 2. The refrigerant heater according to claim 1, wherein said pipe fixing means also serves as a heat shield cover for suppressing heat dissipation from said cylindrical body. 3. The refrigerant pipe in the refrigerant heater is provided in a meandering manner so as to reciprocate in a circumferential direction with respect to a side surface of the cylindrical body. Refrigerant heater. 4. The refrigerant pipe according to claim 1, wherein a refrigerant pipe in the refrigerant heater is provided in a meandering manner so as to reciprocate in a longitudinal direction with respect to a side surface of the cylindrical body. Refrigerant heater. 5. A refrigerant heater according to claim 1, 2, 3, or 4, and a compressor for sucking and compressing the refrigerant vaporized in the refrigerant heater and sending it to an indoor heat exchanger. Outdoor unit. 6. The outdoor unit according to claim 5, wherein one of the refrigerant heater and the outdoor heat exchanger is selectively operated to heat and vaporize the refrigerant liquefied in the indoor heat exchanger. unit. 7. An outdoor unit having the outdoor heat unit according to claim 5 or 6, and an indoor heat exchanger that heats indoor air by condensing and liquefying the refrigerant delivered from the outdoor unit during the heating operation. An air conditioner comprising: