JP2010156490A - Air conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning device suppressing growing of ice on the bottom plate of an outdoor unit without using an electric heater. <P>SOLUTION: In this air conditioning device 1, the circulating direction of a refrigerant in defrosting operation is opposite to that in heating operation, and a hot gas bypass 10h is disposed. One end A1 of the hot gas bypass 10h is connected to the discharge pipe 10a of a compressor 21, and the other end C1 is connected to a liquid pipe 10c connecting an expansion valve 24 to an indoor heat exchanger 41. The hot gas bypass 10h is disposed on the bottom plate 2b of the outdoor unit 2, and passes near drain ports 86a-86e. In the defrosting operation, pressure difference is generated between both ends of the bypass, and a high-pressure refrigerant flows into the hot gas bypass 10h from a discharge pipe 10a side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air conditioner using a vapor compression refrigeration cycle.

  Since the outdoor heat exchanger of the air conditioner functions as a refrigerant evaporator during heating operation, moisture contained in outdoor air is condensed on the surface of the outdoor heat exchanger. In this state, when the outdoor heat exchanger is exposed to a low temperature environment, the condensed water freezes, and the surface of the outdoor heat exchanger is covered with ice, so that the heat exchange performance is deteriorated. The ice covering the surface of the outdoor heat exchanger melts by flowing hot gas through the outdoor heat exchanger during the defrosting operation, but the drain water generated at that time accumulates on the bottom plate that supports the outdoor heat exchanger and again to freeze. The ice that grows by repeating this presses on the outdoor heat exchanger, and further contacts with an outdoor fan arranged in the vicinity of the outdoor heat exchanger, thereby inhibiting the rotation of the outdoor fan.

In order to avoid such a situation, a technique has been proposed in which an electric heater is installed on the upper surface side of the bottom plate to prevent the drain water from freezing (see, for example, Patent Document 1). According to the invention according to Patent Document 1, since the water melted by the electric heater is drained through the drain hole provided in the bottom plate, the growth of ice on the upper surface of the bottom plate is suppressed. However, in the air conditioning apparatus as described above, since it is necessary to newly include an electric heater, the number of parts is increased and the cost is increased.
JP 2008-96018 A

  The subject of this invention is providing the air conditioning apparatus which can suppress the growth of the ice on an outdoor unit bottom plate, without using an electric heater.

  The air conditioner according to the first aspect of the invention performs the heating operation by circulating the refrigerant in the order of the compressor, the indoor heat exchanger, the expansion mechanism, and the outdoor heat exchanger, and the circulation direction of the refrigerant during the defrosting operation is the heating operation. It is an air conditioner dedicated to heating that is the opposite of time, and includes a bypass and a second heating target member. The bypass bypasses a part of the refrigerant toward the outdoor heat exchanger during the defrosting operation. A 2nd heating object member is heating objects other than the outdoor heat exchanger heated with a refrigerant | coolant at the time of a defrost operation, and is heated with the refrigerant | coolant which passes a bypass. One end of the bypass is connected to the discharge pipe of the compressor, and the other end is connected to a pipe connecting the expansion mechanism and the indoor heat exchanger.

  In this air conditioner, there is no pressure difference between both ends of the bypass during the heating operation, so that the refrigerant does not flow into the bypass. During the defrosting operation, a pressure difference occurs between both ends of the bypass, and the refrigerant flows into the bypass from the discharge pipe side. As a result, the ice that has started to grow on the second member to be heated is melted by the heat radiation of the high-pressure refrigerant that circulates in the bypass, so that the ice growth is suppressed. In addition, during the defrosting operation, the refrigerant flows due to the pressure difference between both ends of the bypass, so that it is economical that there is no need to provide a specific valve in the bypass.

  The air conditioner according to a second aspect of the present invention is the air conditioner according to the first aspect of the present invention, wherein the second member to be heated is located below the outdoor heat exchanger. The bypass is disposed on the second heating target member.

  In this air conditioner, even when the water generated in the defrosting operation stays in the second heating target member and freezes, the ice is melted for each defrosting operation, so that ice accumulates on the second heating target member. Is suppressed, and the outdoor heat exchanger or the like above the second heating target member is prevented from being pressed.

  An air conditioner according to a third aspect of the present invention is the air conditioner according to the second aspect of the present invention, wherein the second heating target member has a drain outlet that penetrates in the vertical direction. The bypass passes near the drain.

  In this air conditioner, even when the drain outlet is blocked by freezing of water, ice is melted and drained every time the defrosting operation is performed, so that the accumulation of ice on the second heating target member is suppressed. Thus, it is possible to prevent the outdoor heat exchanger or the like above the second heating target member from being pressed.

  An air conditioner according to a fourth aspect of the present invention is the air conditioner according to the first aspect of the present invention, wherein the bypass is provided with a throttle portion that reduces the cross-sectional area of the refrigerant flow passage. In this air conditioner, during the defrosting operation, the ratio between the refrigerant flowing through the outdoor heat exchanger and the refrigerant flowing through the bypass is kept constant.

  In the air conditioner according to the first aspect of the present invention, the ice that has started to grow on the second member to be heated is melted by the heat radiation of the high-pressure refrigerant that circulates in the bypass, so that the ice growth is suppressed. Further, there is no need to provide a specific valve for the bypass, which is economical.

  In the air conditioner according to the second or third invention, the accumulation of ice on the second heating target member is suppressed, and the outdoor heat exchanger or the like above the second heating target member is prevented from being compressed. Is done.

  In the air conditioner according to the fourth aspect of the present invention, the ratio of the refrigerant flowing through the outdoor heat exchanger and the refrigerant flowing through the bypass is kept constant during the defrosting operation.

  Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention.

<Air conditioning device>
FIG. 1 is a refrigerant circuit diagram of an air conditioner using a refrigeration apparatus according to an embodiment of the present invention. In FIG. 1, in an air conditioner 1, an outdoor unit 2 as a heat source side device and an indoor unit 4 as a usage side device are connected by a refrigerant pipe, and a refrigerant circuit 10 for performing a vapor compression refrigeration cycle is formed. Yes.

  The outdoor unit 2 contains a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an expansion valve 24, an accumulator 25, an outdoor fan 26, a capillary tube 28, and an electromagnetic induction heating unit 6. The indoor unit 4 houses an indoor heat exchanger 41 and an indoor fan 42.

  The refrigerant circuit 10 includes a discharge pipe 10a, a gas pipe 10b, a liquid pipe 10c, an outdoor liquid pipe 10d, an outdoor gas pipe 10e, an accumulator pipe 10f, a suction pipe 10g, and a hot gas bypass 10h.

  The discharge pipe 10 a connects the compressor 21 and the four-way switching valve 22. The gas pipe 10 b connects the four-way switching valve 22 and the indoor heat exchanger 41. The liquid pipe 10 c connects the indoor heat exchanger 41 and the expansion valve 24. The outdoor liquid pipe 10 d connects the expansion valve 24 and the outdoor heat exchanger 23. The outdoor gas pipe 10 e connects the outdoor heat exchanger 23 and the four-way switching valve 22.

  The accumulator pipe 10 f connects the four-way switching valve 22 and the accumulator 25. The electromagnetic induction heating unit 6 is attached to a part of the accumulator tube 10f. Of the accumulator tube 10f, at least in the heated portion covered by the electromagnetic induction heating unit 6, the periphery of the copper tube is covered with a stainless steel tube. Of the piping constituting the refrigerant circuit 10, the portion other than the stainless steel tube is a copper tube.

  The suction pipe 10g connects the accumulator 25 and the suction side of the compressor 21. The hot gas bypass 10h connects a branch point A1 provided in the middle of the discharge pipe 10a and a branch point C1 provided in the middle of the liquid pipe 10c.

  The hot gas bypass 10h is provided with a capillary tube 28 that reduces the cross-sectional area of the refrigerant flow passage. During the defrosting operation, the refrigerant that circulates through the outdoor heat exchanger 23 and the refrigerant that circulates through the hot gas bypass 10h. The ratio is kept constant.

  The four-way switching valve 22 can switch between a heating operation cycle and a defrosting operation cycle. In FIG. 1, the connection state for performing the heating operation is indicated by a solid line, and the connection state for performing the defrosting operation is indicated by a dotted line. During the heating operation, the indoor heat exchanger 41 functions as a condenser, and the outdoor heat exchanger 23 functions as an evaporator. During the defrosting operation, the outdoor heat exchanger 23 functions as a condenser, and the indoor heat exchanger 41 functions as an evaporator.

  An outdoor fan 26 that sends outdoor air to the outdoor heat exchanger 23 is disposed in the vicinity of the outdoor heat exchanger 23. An indoor fan 42 that sends room air to the indoor heat exchanger 41 is disposed in the vicinity of the indoor heat exchanger 41.

  The control unit 11 includes an outdoor control unit 11a and an indoor control unit 11b. The outdoor control unit 11a and the indoor control unit 11b are connected by a communication line 11c. And the outdoor control part 11a controls the apparatus arrange | positioned in the outdoor unit 2, and the indoor control part 11b controls the apparatus arrange | positioned in the indoor unit 4. FIG.

(Appearance of outdoor unit)
FIG. 2 is an external perspective view of the outdoor unit viewed from the front side. 2, the outer shell of the outdoor unit 2 includes a top plate 2a, a bottom plate (invisible) facing the top plate 2a, a front panel 2c, a fan guard 2k, a right side panel 2f, and a left side panel facing the right side panel 2f. (Invisible), a substantially rectangular parallelepiped shape is formed by the rear panel (invisible) facing the front panel 2c and the fan guard 2k.

(Inside the outdoor unit)
FIG. 3 is a perspective view of the outdoor unit from which the front panel, the right side panel, and the back panel are removed. In FIG. 3, the outdoor unit 2 is divided into a blower room and a machine room by a partition plate 2h. An outdoor heat exchanger 23 and an outdoor fan (invisible) are arranged in the blower room, and an electromagnetic induction heating unit 6, a compressor 21, and an accumulator 25 are arranged in the machine room.

  FIG. 4 is a perspective view of the outdoor unit from which members other than the bottom plate, the outdoor heat exchanger, and the outdoor fan are removed. In FIG. 4, the outdoor heat exchanger 23 is a fin-and-tube heat exchanger formed in an L shape. Two outdoor fans 26 are arranged between the fan guard 2k (see FIG. 3) and the outdoor heat exchanger 23 so as to be adjacent to each other in the vertical direction via a support base. As the outdoor fan 26 rotates, outdoor air is sucked from the vents of the left side panel and the rear panel, passes between the fins of the outdoor heat exchanger 23, and is blown out from the fan guard 2k.

(Structure near the bottom plate of the outdoor unit)
FIG. 5 is a plan view of the outdoor unit from which members other than the bottom plate and the machine room are removed. In FIG. 5, the outdoor heat exchanger 23 is drawn by a two-dot chain line so that the position of the outdoor heat exchanger 23 can be understood. The hot gas bypass 10h is arranged on the bottom plate 2b, extends from the machine room side where the compressor 21 is located to the blower room side, goes around the blower room side bottom, and returns to the machine room side. About half of the total length of the hot gas bypass 10 h is located below the outdoor heat exchanger 23. Further, drainage ports 86a to 86e penetrating the bottom plate 2b in the thickness direction are formed in a portion of the bottom plate 2b located below the outdoor heat exchanger 23.

(Electromagnetic induction heating unit)
FIG. 6 is a cross-sectional view of the electromagnetic induction heating unit. In FIG. 6, the electromagnetic induction heating unit 6 is arranged so as to cover the heated portion of the accumulator tube 10f from the radially outer side, and heats the heated portion by electromagnetic induction heating. The heated portion of the accumulator tube 10f has a double tube structure with an inner copper tube and an outer stainless steel tube 100f. The stainless steel material used for the stainless steel pipe 100f is a ferritic stainless steel containing 16 to 18% chromium, or a precipitation hardening system containing 3 to 5% nickel, 15 to 17.5% chromium, and 3 to 5% copper. Stainless steel is selected.

  The electromagnetic induction heating unit 6 is first positioned on the accumulator tube 10 f, then the vicinity of the upper end is fixed by the first hex nut 61, and finally the vicinity of the lower end is fixed by the second hex nut 66.

  The coil 68 is spirally wound around the outside of the bobbin main body 65. The coil 68 is accommodated inside the ferrite case 71. The ferrite case 71 further accommodates a first ferrite part 69 and a second ferrite part 70.

  The first ferrite portion 69 is formed of ferrite having a high magnetic permeability, and forms a path of magnetic flux together with the stainless steel tube 100f when a current is passed through the coil 68. The first ferrite part 69 is located on both ends of the ferrite case 71.

  The second ferrite portion 70 is different in position and shape from the first ferrite portion 69, but its function is the same as that of the first ferrite portion 69, and is disposed in the vicinity of the outside of the bobbin main body 65 in the accommodating portion of the ferrite case 71. The

<Operation of air conditioner>
The air conditioner 1 can be switched to either the heating operation or the defrosting operation by the four-way switching valve 22.

(Heating operation)
In the heating operation, the four-way switching valve 22 is set to the state shown by the solid line in FIG. When the compressor 21 is operated in this state, the refrigerant circuit 10 performs a vapor compression refrigeration cycle in which the outdoor heat exchanger 23 serves as an evaporator and the indoor heat exchanger 41 serves as a condenser.

  The high-pressure refrigerant discharged from the compressor 21 is condensed by exchanging heat with indoor air in the indoor heat exchanger 41. Then, the air whose temperature has increased due to heat exchange with the refrigerant is blown out into the air-conditioning target space. The condensed refrigerant is decompressed when passing through the expansion valve 24, and then evaporates by exchanging heat with outdoor air in the outdoor heat exchanger 23. The refrigerant that has passed through the outdoor heat exchanger 23 is sucked into the compressor 21 and compressed.

  When the heating operation is started, particularly when the compressor 21 is not sufficiently warmed, the electromagnetic induction heating unit 6 heats the accumulator pipe 10f, so that the compressor 21 can compress the warmed refrigerant. As a result, the temperature of the gas refrigerant discharged from the compressor 21 rises, and the lack of heating capacity at startup is compensated.

(Defrosting operation)
When the heating operation is performed, moisture contained in the air condenses on the surface of the outdoor heat exchanger 23, forms frost or freezes, covers the surface of the outdoor heat exchanger 23, and reduces the heat exchange performance. For this reason, defrosting operation is performed in order to melt frost or ice adhering to the outdoor heat exchanger 23.

  In the defrosting operation, the four-way switching valve 22 is set to the state indicated by the dotted line in FIG. When the compressor 21 is operated in this state, the refrigerant circuit 10 performs a vapor compression refrigeration cycle in which the outdoor heat exchanger 23 serves as a condenser and the indoor heat exchanger 41 serves as an evaporator.

  The high-pressure refrigerant discharged from the compressor 21 is condensed by exchanging heat with outdoor air in the outdoor heat exchanger 23. The frost or ice covering the outdoor heat exchanger 23 is melted by the heat radiation from the refrigerant. The refrigerant which has dissipated heat and is condensed is reduced in pressure when passing through the expansion valve 24, and then is evaporated by exchanging heat with indoor air in the indoor heat exchanger 41. At this time, the indoor fan 42 is stopped. This is because when the indoor fan 42 is operated, the cooled air is blown into the air-conditioning target space and the comfort is impaired. The refrigerant that has passed through the indoor heat exchanger 41 is sucked into the compressor 21 and compressed.

  Further, during the defrosting operation, the electromagnetic induction heating unit 6 heats the accumulator tube 10f, so that the compressor 21 can compress the warmed refrigerant. As a result, the temperature of the gas refrigerant discharged from the compressor 21 increases, and the defrosting capability is improved.

  Further, during the defrosting operation, the hot gas bypass 10h has a high pressure at point A1 and a low pressure at the point C1, causing a pressure difference, so that the high pressure refrigerant discharged from the compressor 21 also flows through the hot gas bypass 10h. Even when ice is growing on the bottom plate 2b of the outdoor unit 2, the ice is melted by heat radiation from the refrigerant passing through the hot gas bypass 10h. The water generated at that time is drained from the drain ports 86a to 86e. Further, since the drain ports 86a to 86e are also heated by the hot gas bypass 10h, the drain ports 86a to 86e are prevented from being blocked by freezing.

  FIG. 7 is a time chart showing the operation of the four-way switching valve and the compressor before and after the defrosting operation. In FIG. 7, when a defrost request signal is transmitted and a predetermined time has elapsed, the four-way switching valve 22 is switched from the state indicated by the solid line (heating side) in FIG. 1 to the state indicated by the dotted line (defrosting side). The operating frequency of the compressor 21 changes to a preset frequency after the four-way switching valve 22 is switched. Further, in the air conditioner 1, since the defrost request signal is used as a starting point until the four-way switching valve 22 is switched to the defrost side, the control for reducing the operating frequency of the compressor 21 is performed. Impact is reduced when the direction of circulation is reversed.

  And when the defrost operation is complete | finished, the four-way selector valve 22 switches to the heating side. Further, in the air conditioner 1, since the control for stopping the operation of the compressor 21 is performed before the four-way switching valve 22 is switched to the heating side, the four-way switching valve 22 is switched to the heating side. The impact is suppressed.

<Features>
The air conditioner 1 is a heating-only air conditioner in which the refrigerant circulation direction during the defrosting operation is opposite to that during the heating operation, and includes a hot gas bypass 10h. One end A1 of the hot gas bypass 10h is connected to the discharge pipe 10a of the compressor 21, and the other end C1 is connected to the liquid pipe 10c connecting the expansion valve 24 and the indoor heat exchanger 41. The hot gas bypass 10h is disposed on the bottom plate 2b of the outdoor unit 2 and passes through the vicinity of the drain ports 86a to 86e. During the defrosting operation, a pressure difference occurs between both ends of the bypass, and the high-pressure refrigerant flows into the hot gas bypass 10h from the discharge pipe 10a side. As a result, the ice that has started to grow on the bottom plate 2b is melted by the heat radiation of the high-pressure refrigerant flowing through the hot gas bypass 10h, so that the ice grows and the outdoor heat exchanger 23 and the outdoor fan 26 above the bottom plate 2b. It is prevented that pressure is applied. Moreover, since it is not necessary to provide a specific valve in the hot gas bypass 10h, it is economical.

  The present invention is useful for an air conditioner for cold regions.

The refrigerant circuit figure of the air conditioning apparatus using the freezing apparatus which concerns on one Embodiment of this invention. The external appearance perspective view of the outdoor unit seen from the front side. The perspective view of the outdoor unit which removed the front panel, the right side panel, and the back panel. The perspective view of the outdoor unit which removed members other than a baseplate, an outdoor heat exchanger, and an outdoor fan. The top view of the outdoor unit which removed members other than a baseplate and a machine room. Sectional drawing of an electromagnetic induction heating unit. The time chart which shows operation | movement of the four-way switching valve before and behind defrost operation, and a compressor.

Explanation of symbols

2b Bottom plate (second heating target member)
10h Hot gas bypass 21 Compressor 23 Outdoor heat exchanger 24 Expansion valve 28 Capillary tube (throttle part)
41 Indoor heat exchangers 86a to 86e

Claims (4)

The refrigerant is circulated in the order of the compressor (21), the indoor heat exchanger (41), the expansion mechanism (24), and the outdoor heat exchanger (23) to perform the heating operation, and the circulation direction of the refrigerant during the defrosting operation. Is an air conditioner dedicated to heating that is the reverse of the heating operation,
A bypass (10h) for bypassing a part of the refrigerant toward the outdoor heat exchanger (23) during the defrosting operation;
A heating target other than the outdoor heat exchanger (23) heated by the refrigerant during the defrosting operation, a second heating target member (2b) heated by the refrigerant passing through the bypass (10h);
With
One end of the bypass (10h) is connected to a discharge pipe (10a) of the compressor (21), and the other end is connected to a pipe (10c) connecting the expansion mechanism (24) and the indoor heat exchanger (41). It is connected,
Air conditioner. The second heating target member (2b) is located below the outdoor heat exchanger (23),
The bypass (10h) is disposed on the second heating target member (2b).
The air conditioning apparatus according to claim 1. The second heating target member (2b) has drain ports (86a to 86e) penetrating in the vertical direction,
The bypass (10h) passes through the vicinity of the drain ports (86a to 86e).
The air conditioning apparatus according to claim 2. The bypass (10h) is provided with a throttle part (28) for reducing the cross-sectional area of the refrigerant flow passage.
The air conditioning apparatus according to claim 1.

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