JPH0297854A - Heat pump type air conditioner - Google Patents

Abstract

PURPOSE:To improve a startup performance of heating operation by preventing refrigerant from being melted into refrigerating machine oil. CONSTITUTION:During heating operation, a refrigerant which is adapted to close an on/off valve 12 and control a throttle means 7 in conformity with operating status, returns to a compressor 1 by way of a check valve 3, a four way valve 2, an indoor heat exchanger 5, a throttle means 7, an outdoor heat exchanger 6, a suction pipe 10, and an accumulator 9. When the operation is suspended, the throttle means 7 is closed, the both ends of the indoor heat exchanger 5 are closed with a check valve 2 and the throttle means 7 so that high pressure refrigerant may be stored in the indoor heat exchanger 5, thereby preventing its counter flow to the side of the compressor 1. During a start up time in heating operation, a four way valve 2 is positioned to heating service, an on/off valve 12 is opened, and a throttle means 7 is closed, thereby heating refrigerating machine oil in order to inhibit the melting of refrigerant and hence increasing a circulation of flow rate of the refrigerant in a refrigerant circuit. The on/off valve 12 is closed while the throttle means 7 is controlled to an opening in conformity with the operating status.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat pump type air conditioner.

[Prior Art] As a conventional heat pump type air conditioner of this type, the technology disclosed in Japanese Patent Application Laid-Open No. 63-32261 can be mentioned.

FIG. 7 is a refrigerant circuit diagram showing a conventional heat pump type air conditioner.

In the figure, (51) is a compressor, (52) is a four-way valve that can be switched to heating or cooling position, (53) is an indoor heat exchanger, and (54) is a throttle consisting of an expansion valve whose opening can be controlled. Means (55) is an outdoor heat exchanger, (56) is a bypass pipe, one end of which is connected to a refrigerant pipe (57) between the throttle means (54) and the outdoor heat exchanger (55). At the same time, the other end is connected to the suction pipe (58) of the compressor (51). (59) is the bypass pipe (56)
The on-off valve disposed above, (60) is a sensor that detects the temperature of the compressor (51), and (61) is a sensor that detects the temperature of the refrigerant gas sucked into the compressor (51).

Next, the operation of the conventional heat pump air conditioner configured as described above will be explained.

During normal heating operation, the four-way valve (52) is switched to the heating position, the on-off valve (59) is closed, and the throttle means (54) is controlled to an opening degree according to the operating situation. The refrigerant discharged from the compressor (51) passes through the four-way valve (52) and flows into the indoor heat exchanger (53) as shown by the solid arrow, where it heats the indoor air by heat radiation. It enters the outdoor heat exchanger (55) through the throttle means (54) and the refrigerant pipe (57), where it is evaporated and cooled by heat absorption from the outside air, and then the four-way valve (52) and the suction pipe (58) The process then returns to compression 1 (51).

During normal cooling operation, the four-way valve (52) is switched to the cooling position, the on-off valve (59) is closed, and the throttle means (54) is controlled to an opening degree depending on the operating situation. The refrigerant discharged from the compressor (51) is then transferred to the four-way valve (52), the outdoor heat exchanger (55L refrigerant piping (
57), throttle means (54), indoor heat exchanger (53), four-way valve (52), and suction pipe (58) to the compressor (51).
Return to

By the way, when the heating operation is stopped, particularly when the outside temperature is low, the refrigerant dissolves into the refrigerating machine oil of the compressor (51). Therefore, when heating operation is started in this state, the amount of refrigerant circulated is small, so the heat radiation period in the indoor heat exchanger (53) is reduced, and the speed of temperature rise of the indoor air is reduced.

Therefore, prior to the above-mentioned normal heating operation, a start-up operation is performed as follows.

When the outside temperature is about 15°C, start-up operation is performed by setting the four-way valve (52) to the heating position (solid line position in the figure), opening the on-off valve (59), and widening the opening of the throttle means (54). It will be done. Then, the refrigerant discharged from the compression tl (51) passes through the four-way valve (
52), passes through the indoor heat exchanger (53) and the throttle means (54) to reach the refrigerant pipe (57), which is branched off and mostly passes through the bypass pipe (56) and the on-off valve (59) to the suction pipe. (58), the remainder passes through the outdoor heat exchanger (55), four-way valve (52), and suction pipe (58), joins with the previously branched refrigerant, and returns to the compressor (51).

In this case, since the opening degree of the throttle means (54) is large, the refrigerant is hardly throttled and most of it flows into the compressor (51) through the bypass pipe (56) with low flow resistance. Therefore, the specific volume of the refrigerant sucked into the compressor (51) decreases, and the discharge amount and discharge pressure of the compressor (51) increase. As a result, the temperature of the compressor (51) rises, and the refrigerant dissolved in the refrigerating machine oil in the compressor (51) is gasified and separated from the refrigerating machine oil.

As a result of this start-up operation, when the temperature of the compressor (51) reaches a predetermined temperature, the sensor (60) detects this, the on-off valve (59) is closed, and the throttle means (54) is controlled to an opening degree according to the operating situation, and the above-mentioned normal heating operation is started.

On the other hand, when the outside temperature is around 110 degrees Celsius, the four-way valve (52
) to the cooling position (dotted line position in the figure), open the on-off valve (59),
Start-up operation is performed with the throttle means (54) fully open.

In this case, the refrigerant discharged from the compression IN (51) is
It passes through the four-way valve (52), the outdoor heat exchanger (55), the bypass pipe (56), the on-off valve (59) and the suction pipe (58) and returns to the compression II (51) in the form of a gas refrigerant. Therefore, the temperature and pressure of the refrigerant discharged from the compressor (51) rise, and the refrigerant dissolved in the refrigerating machine oil of the compressor (51) is gasified and separated from the refrigerating machine oil, and the refrigerant enters the refrigerant circuit. The amount of refrigerant circulated increases. As a result of this start-up operation, when the temperature of the compressor (51) reaches a predetermined temperature, the sensor (60) detects this and the four-way valve (52) is switched to the heating position and opened/closed. valve(
59) is closed, and the throttle means (54) is controlled to an opening degree according to the operating conditions, and the above-mentioned normal heating operation begins.

[Problem to be Solved by the Invention] However, as described above, the conventional heat pump type air conditioner is not equipped with a means for suppressing refrigerant from penetrating into the refrigerating machine oil when compression II (51) is stopped. Therefore, a large amount of refrigerant dissolves into the refrigerating machine oil while the compressor (51) is stopped. Therefore, before starting normal heating operation,
It was necessary to perform a long FJ & short start-up operation to heat the refrigerating machine oil and expel the refrigerant from it. As a result, the indoor temperature could not be raised rapidly.

In addition, when a conventional heat pump air conditioner is operated from defrost 1, it is necessary to perform the start-up operation when the outside temperature is about -10°C after the defrost operation is completed, and compression II (51) is required. The sucked refrigerant liquefies and the refrigerating machine oil is cooled to a low temperature. As a result, the solubility of the refrigerant in the refrigerating machine oil increases, and compression 1 (51) is started with a large amount of refrigerant accumulated, which is what is called a sleep start.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a heat pump air conditioner that can efficiently suppress the infiltration of refrigerant into refrigerating machine oil and improve the start-up performance of heating operation.

[Means for Solving the Problems] The heat pump type air conditioner of the present invention as set forth in claim 1 includes a compressor, a four-way valve that can be switched between a heating position and a cooling position, and a four-way valve that flows toward the compressor from the four-way valve. A check valve that prevents backflow of refrigerant, a throttle means that can control the opening and is located between the indoor heat exchanger and the outdoor heat exchanger, and an accumulator that is located on the suction side of the compressor; It consists of an on-off valve disposed on a bypass pipe connecting the accumulator and the discharge side of the compressor.

The heat pump air conditioner of the present invention as set forth in claim 2 includes a compressor, a four-way valve that can be switched between a heating position and a cooling position, and a check valve that prevents the refrigerant from flowing backward from the four-way valve toward the compressor. , a throttle means that can control the opening degree arranged between the indoor heat exchanger and the outdoor heat exchanger, an accumulator arranged on the suction side of the compressor, and a heater that heats the refrigerating machine oil in the compressor. It is composed of.

The heat pump type air conditioner of the present invention as set forth in claim 3 includes a compressor, a four-way valve that can be switched between a heating position and a cooling position, and a check valve that prevents backflow of refrigerant from the four-way valve toward the compressor. , a throttle means that can control the opening degree arranged between the indoor heat exchanger and the outdoor heat exchanger, an accumulator arranged on the suction side of the compressor, and a heater that heats the refrigerating machine oil in the compressor. , a defrost on-off valve disposed on the defrost piping, and a capillary tube disposed on the pressure reducing piping.

The heat pump type air conditioner of the present invention described in claim 4 includes a compressor with a built-in motor, an inverter that changes the frequency of the motor, a four-way valve that can be switched to a heating position and a cooling position, and a four-way valve. A check valve that prevents the backflow of refrigerant toward the compressor, a throttle means that can control the opening and is located between the indoor heat exchanger and the outdoor heat exchanger, and a throttle means that is located on the suction side of the compressor. It consists of an accumulator, a defrost on-off valve disposed on the defrost piping, and a capillary tube disposed on the pressure reducing piping.

[Function] In the heat pump air conditioner according to the first aspect, the throttling means is closed when the heating operation is stopped.

Therefore, the refrigerant is confined within the seedling heat exchanger between the check valve and the throttling means, and dissolution of the refrigerant into the refrigerating machine oil in the compressor is suppressed. During start-up operation, the four-way valve is switched to the heating position, the on-off valve is opened, and the throttle means is switched to closed. Therefore, the refrigerant is circulated in a circuit from the compressor to the accumulator via the bypass pipe, and the refrigerating machine oil in the compressor is maintained at a high temperature. Therefore, the solubility of the refrigerant in the refrigerating machine oil decreases, making it difficult for the refrigerant to dissolve.

During normal heating operation, the on-off valve is closed and the throttle means is switched to an opening degree that corresponds to the operating situation.

In the heat pump air conditioner according to the second aspect of the invention, the throttle means is closed when the heating operation is stopped.

Therefore, similarly to the above-mentioned invention, dissolution of the refrigerant into the refrigerating machine oil is suppressed. Further, the heater is activated a predetermined time before starting the heating operation, and the refrigerating machine oil is heated to a high temperature, thereby reducing the solubility of the refrigerant in the refrigerating machine oil. During normal heating operation, the heater is stopped, and the throttle means is switched to an opening degree that corresponds to the operating conditions.

In the heat pump type air conditioner according to the third aspect of the present invention, the throttling means is closed when the heating operation is stopped, thereby suppressing the infiltration of the refrigerant into the refrigerating machine oil. Further, the heater is activated a predetermined time before starting the defrost operation. Therefore, the solubility of the refrigerant in the refrigerating machine oil decreases. In this state, the four-way valve is set to the heating position, the throttling means is opened, and the defrost opening/closing valve is opened to start defrosting operation. Then, the heater is stopped, the defrost opening/closing valve is closed, and the throttle means is switched to be controlled to an opening degree that corresponds to the operating conditions, thereby transitioning to normal heating operation.

In the heat pump air conditioner according to the fourth aspect of the present invention, the throttling means is closed when the heating operation is stopped, thereby suppressing the refrigerant from entering the refrigerating machine oil. During defrost single operation, the four-way valve is placed in the heating position, the throttling means is closed, the defrost opening/closing valve is opened, and the compressor motor is driven by the inverter at a frequency with large heat loss. Therefore, the refrigerating machine oil is heated by the heat generated by the motor, and the solubility of the refrigerant in the refrigerating machine oil decreases. Then, the frequency of the motor is returned to the normal value, the defrost opening/closing valve is closed, and the throttle means is switched to be controlled to an opening degree according to the operating conditions, and normal heating operation is started.

[Example] The present invention will be explained in detail below.

FIG. 1 is a refrigerant circuit diagram of a heat pump air conditioner according to the first embodiment of the present invention, and FIG. 2 is a characteristic showing temporal changes in the discharge pressure and suction pressure of the compressor in the refrigerant circuit of FIG. 1. 3 is a refrigerant circuit diagram of a heat pump type air conditioner according to the second embodiment of the present invention, and FIG. 4 shows temporal changes in the discharge pressure and suction pressure of the compressor in the refrigerant circuit of FIG. 3. Characteristic diagram shown, No. 5
The figure is a refrigerant circuit diagram of a heat pump type air conditioner according to a third embodiment of the present invention, and FIG. 6 is a refrigerant circuit diagram of a heat pump type air conditioner according to a fourth embodiment of the present invention. Note that in the figures, the same reference numerals and symbols indicate the same or equivalent parts.

First Embodiment> In Fig. 1, (1) is a compressor that compresses refrigerant using external power (q), and (2) is connected to the discharge side of the compressor (1) and is connected to the heating position and the cooling position. The four-way valve (3) is a check valve disposed on the discharge pipe (4) between the four-way valve (2) and the compressor (1);
) to the compressor (1).

(5) is an indoor heat exchanger to which high temperature refrigerant is supplied from the compressor (1) via the check valve (3) and the four-way valve (2) in the heating position, and (6) is from the compressor 1 (1). An outdoor heat exchanger to which high-temperature refrigerant is supplied via a check valve (3) and a four-way valve (2) in the cooling position, and (7) are the indoor heat exchanger (5) and the outdoor heat exchanger (6). This is a throttling means such as an expansion valve whose opening degree can be controlled and which is disposed on the refrigerant pipe (8) between the refrigerant pipe and the refrigerant pipe (8).

(9) is an accumulator disposed on the suction side of the compressor (1), and (11) is a suction pipe (10) between the suction side of the accumulator (9) and the four-way valve (2) and the check valve ( 3
), (12) is an on-off valve disposed on the bypass pipe (11), and (13) detects the temperature of the compressor (1). It is a sensor that

Next, the operation of the heat pump air conditioner of the first embodiment configured as described above will be explained.

During normal cooling operation, the four-way valve (2) is switched to the cooling position, the on-off valve (12) is closed, and the throttle means (7) is controlled to an opening degree depending on the operating situation. And the compressor (
1) The refrigerant discharged from the four-way valve (2), the outdoor heat exchanger (6), the refrigerant pipe (8), the throttle means (7), the indoor heat exchanger (5), the four-way valve (2), and the suction It returns to the compressor (1) via the pipe (10) and the accumulator (9).

During normal heating operation, the four-way valve (2) is switched to the heating position, the on-off valve (12) is closed, and the throttle means (7) is switched to be controlled to an opening degree depending on the operating situation. The refrigerant discharged from the compressor (1) is transferred to the check valve (3), the four-way valve (2), the indoor heat exchanger (5), the throttle means (7), as shown by the solid arrow in the figure. Outdoor heat exchanger (6
), the four-way valve (2), the suction pipe (10) and the accumulator (9) before returning to the compressor (1).

When the heating operation is stopped, the throttle means (7) is closed.

Therefore, both ends of the indoor heat exchanger (5) are closed by the check valve (2) and the throttle means (7), and the high-pressure refrigerant is distributed within the indoor heat exchanger (5) as it is during operation. is stored in Therefore, backflow of the high-pressure refrigerant toward the compressor (1) is prevented, and dissolution of the refrigerant into the refrigerating machine oil in the compressor (1) is suppressed.

At the start of the heating operation, the four-way valve (2) is placed in the heating position, the on-off valve (12) is opened, and the throttle means (7) is closed, and a start-up operation is performed for a predetermined period of time. Then, the high temperature, high pressure refrigerant gas discharged from the compressor (1) returns to the compressor (1) through the bypass pipe (11) and the accumulator (9), as shown by the dotted arrow. In this case, an indoor heat exchanger (5
) and the outdoor heat exchanger (6), the suction temperature and discharge temperature of the compressor (1) rise rapidly, causing the cylinder and refrigerating machine oil in the compressor (1) to Heated to high temperatures. Therefore, the solubility of the refrigerating machine oil decreases in inverse proportion to its temperature, the refrigerant dissolved in the refrigerating machine oil is gasified and separated, and the refrigerant sucked into the compressor @ (1) is dissolved in the refrigerating machine oil. It becomes difficult to melt. As a result, the flow rate of refrigerant circulating in the refrigerant circuit increases.

When the temperature of the compressor (1) reaches a predetermined temperature, the sensor (13) detects it, and based on this, the on-off valve (12) is opened and the throttle means (7) is operated. The opening degree is controlled according to the situation, and the operation shifts to the normal heating operation described above.

In this way, the P1-pump air conditioner of the first embodiment has a compressor (1), a four-way valve (2), a check valve (3),
Indoor heat exchanger (5), outdoor heat exchanger (6), throttling means (
7), an accumulator (9), a bypass pipe (11), and an on-off valve (12).

Therefore, in the heat pump type air conditioner of the first embodiment, by closing the throttle means (7) when the heating operation is stopped, it is possible to suppress the refrigerant from entering the refrigerating machine oil. Also, at the start of heating operation, a four-way valve (2
) is placed in the heating position, the on-off valve (12) is opened, and the throttling means (7) is closed to perform start-up operation for a predetermined period of time, thereby heating the refrigerating machine oil and melting the refrigerant. The circulation flow rate of refrigerant can be increased. Then, by closing the on-off valve (12) and switching the throttle means (7) so that the opening degree is controlled according to the operating conditions, normal heating operation can be started early.

As a result, in FIG. 2, the discharge pressure of the compressor (1) changes as shown by Ha, and the suction pressure changes as shown by Ib. That is, there is already a pressure difference between the discharge pressure Ia and the suction pressure Ib at the start of the heating operation. Although the suction pressure Ib gradually decreases at the beginning of the start-up operation, it does not fall below the pressure during stable operation, so a low pressure pull-in phenomenon does not occur. Further, the discharge pressure Ha does not change at the beginning of the start-up operation due to the check valve (3), but increases rapidly from the time when the on-off valve (12) is switched to close.

In addition, in FIG. 2, [a and nb indicate the discharge pressure and suction pressure of the compressor in the conventional heat pump air conditioner shown in FIG. 7, and as is clear from comparison with this, According to the heat pump type air conditioner of the first embodiment, the time required for starting the heating operation is significantly shortened compared to the conventional one, and the indoor temperature can be rapidly raised.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. In the drawings, the same reference numerals and symbols as in the first embodiment indicate the same or corresponding components as in the first embodiment, and redundant explanation will be omitted here.

The heat pump type air conditioner of this second embodiment is different from the first embodiment in the means for heating compressed 1(1) refrigerating machine oil at the start of heating operation. That is, in this second embodiment, the bypass piping (1
1) and the on-off valve (12) are omitted, and instead of the third
As shown in the figure, a heater (15) for heating refrigerating machine oil is attached to the compressor (1). (16) is the heater (
15).

Next, the operation of the heat pump type air conditioner of the second embodiment configured as described above will be explained.

During normal heating operation, the four-way valve (2) is switched to the heating position (and the throttle means (7) is switched to be controlled to an opening degree depending on the operating situation. Therefore, the compressor (1) The refrigerant discharged from the check valve (3), four-way valve (2), indoor heat exchanger (5), throttling means (7), outdoor heat exchanger (6), four-way valve (2), and accumulator ( 9
) and returns to the compressor (1).

Also, l! ! When the chamber operation is stopped, the throttle means (7) is opened as in the first embodiment. Therefore, the high-pressure refrigerant is confined within the indoor heat exchanger (5) with the same refrigerant distribution during operation, and the refrigerant is prevented from dissolving into the refrigerating machine oil in the compressor (1).

On the other hand, the heater (1
5) is started, and the cylinder and refrigerating machine oil in the compressor (1) are heated to a high temperature.

Therefore, the solubility of the refrigerant in the refrigerating machine oil decreases inversely proportional to the temperature, and the refrigerant dissolved in the refrigerating machine oil is gasified and separated. 1) It becomes difficult for the refrigerant sucked into the refrigerator to dissolve into the refrigerating machine oil.

And compression! I! When the temperature of (1) reaches a predetermined temperature, the sensor (13) detects it, and the throttle means (7) is switched to be controlled to an opening degree according to the operating situation. The operation shifts to the normal heating operation described above.

As described above, the heat pump air conditioner of the second embodiment includes a compressor (1), a four-way valve (2), a check valve (3), an indoor heat exchanger (5), and an outdoor heat exchanger (6). ), aperture means (7
), an accumulator (9), and a heater (15) for heating refrigerating machine oil.

Therefore, in the heat pump type air conditioner of the second embodiment, by closing the throttle means (7) when the heating operation is stopped, it is possible to suppress the refrigerant from entering the refrigerating machine oil. Moreover, by operating the heater (15) a predetermined time before starting the heating operation, it is possible to heat the refrigerating machine oil and melt the refrigerant, thereby increasing the circulating flow rate of the refrigerant in the refrigerant circuit.

As a result, in FIG. 4, the discharge pressure of the compressor (1) changes as shown by E and the suction pressure changes as shown by Ib. That is, there is already a pressure difference between the discharge pressure Ia and the suction pressure Ib at the start of the heating operation. Although the suction pressure Ib gradually decreases at the beginning of the start-up operation, it does not fall below the pressure during stable operation, so a low pressure pull-in phenomenon does not occur. Moreover, unlike the case of the first embodiment, the discharge pressure Ha rises rapidly at the same time as the heating operation starts due to the operation of the heater (15). Therefore, compared to the first embodiment, normal heating operation can be started earlier.

<Third Example> Next, a third embodiment of the present invention will be described with reference to FIG.

In addition, in the figures, the same reference numerals as in the second embodiment indicate the same or corresponding components as those in the second embodiment, and redundant explanation will be omitted here.

In addition to the configuration of the second embodiment, the heat pump type air conditioner of this third embodiment includes a refrigerant circuit for performing defrost operation in cold weather. That is, in FIG.
(17) is a defrost pipe that connects the discharge pipe (4) between the compressor (1) and the check valve (3) and the refrigerant pipe (8) between the outdoor heat exchanger (6) and the throttle means (7). , (18) is a defrost on-off valve disposed on the defrost pipe (17), (19) is a pressure reducing pipe connecting the discharge side of the defrost on-off valve (18) and the suction pipe (10), (20)
) is a capillary tube disposed on the vacuum pipe (19).

Next, the operation of the heat pump type air conditioner of the third embodiment configured as described above will be explained.

Normal l! When operating the J chamber, the defrost on/off valve (18)
is closed, the four-way valve (2) is switched to the heating position, and the throttle means (7) is switched to be controlled to an opening degree depending on the operating situation. Therefore, the compressor (1)
The refrigerant discharged from the check valve (3), four-way valve (2>,
Indoor heat exchanger (5), throttling means (7), outdoor heat exchanger (
6), the four-way valve (2), and the accumulator (9) before returning to the compressor (1).

Further, when the heating operation is stopped, the throttle means (7) is opened as in each of the above embodiments. Therefore, the high-pressure refrigerant is confined within the indoor heat exchanger (5) with the same refrigerant distribution during operation, and the refrigerant is prevented from dissolving into the refrigerating machine oil in the compressor (1).

On the other hand, at a predetermined time before the start of the defrost operation, power supply to the heater (15) is started, and the cylinder and refrigerating machine oil in the compressor (1) are heated to a high temperature. Therefore, the solubility of refrigerant in refrigeration oil decreases inversely with temperature,
The refrigerant dissolved in the refrigerating machine oil is gasified and separated, and as a result, the flow rate of refrigerant circulating in the refrigerant circuit increases.

Next, the heater (15) is kept energized and the four-way valve (
Defrost operation is started by setting 2) to the heating position, closing the throttle means (7), and opening the defrost on-off valve (18). Then, most of the high temperature refrigerant gas discharged from the compressor (1), which serves as a heat source for defrosting, passes through the defrost on-off valve (1).
8) is open, the compressor (1), defrost on-off valve (18), outdoor heat exchanger (6), four-way valve (2), suction pipe (10), and accumulator are opened, as shown by the solid arrows. (9) and then circulates within the circuit returning to the compressor (1). In addition, some high-temperature refrigerant gas flows from the defrost on-off valve (18) to the pressure reduction pipe (19), as shown by the broken line arrow.
After being depressurized through the capillary tube (20),
It flows into the suction pipe (10), joins with the refrigerant used for defrosting, and flows through the accumulator (9) to the compressor (
Return to 1).

During this defrost operation period, the heater (15) continues to be energized, and the high-temperature refrigerant branched to the capillary tube (20) suppresses the drop in refrigerant temperature during defrost attack, so the compressor (1) Refrigerating machine oil is kept at a high temperature. Also, during the defrost operation period, both ends of the indoor heat exchanger (5) are closed by the check valve (2) and the throttling means (7), so that high-pressure refrigerant is not transferred to the compressor (1) side. Backflow is prevented.

In this way, when the defrost operation is completed, the defrost on-off valve (18) is opened and the throttle means (7) is switched to be controlled to an opening degree according to the operating situation.
Then, the power supply to the heater (15) is stopped, and the normal heating operation described above is started.

As described above, the heat pump air conditioner of the third embodiment includes a compressor (1), a four-way valve (2), a check valve (3), an indoor heat exchanger (5), and an outdoor heat exchanger (6). ), aperture means (7
), accumulator (9), heater for refrigerating machine oil (
15), a defrost on-off valve (18) disposed on the defrost pipe (17), and a capillary tube (20) disposed on the pressure reduction pipe (19).

Therefore, in the heat pump type air conditioner of the third embodiment, by closing the throttle means (7) when the heating operation is stopped, it is possible to suppress the refrigerant from entering the refrigerating machine oil. In addition, the heater (
By operating 15), the amount of refrigerant dissolution loss during this period can be reduced, and the defrost operation can be performed efficiently with an abundant refrigerant flow rate. the result,
This prevents the compressor (1) from starting during a sleep period, and significantly reduces the time required to start up heating operation.
It can quickly raise the temperature inside the room. Note that the discharge pressure and suction pressure of the compressor (1) change as shown in FIG. 4, as in the second embodiment.

<Fourth Example> Next, a fourth embodiment of the present invention will be described with reference to FIG.

In addition, in the drawings, the same reference numerals as those in the third embodiment indicate constituent parts that are the same as or correspond to those in the third embodiment, and redundant explanation will be omitted here.

The heat pump type air conditioner of this fourth embodiment is different from the third embodiment in the means for heating the refrigerating machine oil of the compressor (1) during defrost operation. That is, in FIG. 6, (23) is a motor that is built in the compressor (1) and receives power from it, and (24) is an inverter that changes the frequency of the motor (23). and power supply (16)
installed in the electrical circuit between the The heating means of this fourth embodiment is a motor (23) during defrost operation.
) is driven by an inverter (24) at a set frequency with a large heat loss, and the refrigerating machine oil of the compressor (1) is heated by the heat generated by the motor (23). Note that (25) is a sensor that detects the temperature of the refrigerant discharged from the outdoor heat exchanger (6), and the lead wire (
through the throttle means (7) consisting of a temperature-type automatic expansion valve.
)It is connected to the.

Next, the operation of the heat pump type air conditioner of the fourth embodiment configured as described above will be explained.

During normal heating operation and when heating operation is stopped, the heat pump air conditioner of the fourth embodiment operates in the same manner as the third embodiment.

At the start of defrost operation, the four-way valve (2) is switched to the heating position, the throttle means (7) is closed, the defrost on-off valve (18) is opened, and the inverter (2)
4) sets a frequency for the motor (23) that causes large heat loss and poor motor efficiency.

When the compressor (1) is started in this state, the compressor (1)
Since the defrost on-off valve (18) is open, most of the high-temperature refrigerant gas discharged from the compressor (1), the defrost on-off valve (18), and Outdoor heat exchanger (6), four-way valve (2
), is circulated in a circuit that returns to the compressor (1) via the suction pipe (10) and the accumulator (9). In addition, some high-temperature refrigerant gas is depressurized from the defrost on-off valve (18) through the pressure reduction pipe (19) and the capillary tube (20), and then flows into the suction pipe (10), as shown by the dashed arrow. It joins with the refrigerant used for defrosting, and returns to the compressor (1) via the accumulator (9).

During this defrost operation period, the motor (23) is driven by the inverter (24) at a frequency with large heat loss, so the heat generated by the motor (23) causes the compressor (
1) The cylinder and refrigerating machine oil inside are heated to a high temperature. In addition, the high-temperature refrigerant branched to the capillary tube (20) side suppresses a drop in the refrigerant temperature during defrost, so the refrigerating machine oil in the compressor (1) is maintained at a high temperature.

Therefore, the solubility of the refrigerant in the refrigerant oil decreases in inverse proportion to its temperature, and the refrigerant dissolved in the refrigerant oil is gasified and separated, and as a result, the flow rate of the refrigerant circulating in the refrigerant circuit is reduced. To increase. Also, during the defrost operation period, both ends of the indoor heat exchanger (5) are closed by the check valve (2) and the throttling means (7), so the high-pressure refrigerant compressor (1
) side is prevented.

As a result of this defrost operation, when the temperature of the refrigerant discharged from the outdoor heat exchanger (6) reaches a predetermined temperature, it is detected by the sensor (2).
5) is detected, the throttle means (7) is switched to be controlled to an opening degree according to the operating situation, the defrost on-off valve (18) is closed, and the inverter (24
) sets the motor (23) to a normal frequency with less heat loss, and shifts to the above-described normal heating operation.

As described above, the heat pump type air conditioner of the fourth embodiment includes a compressor (1) with a built-in motor (23), an inverter (24) for changing the frequency of the motor (23), a western valve (2), Check valve (3), indoor heat exchanger (5), chamber, external heat exchanger (6), throttling means (7), accumulator (9)
), a defrost on-off valve (18) disposed on the defrost pipe (17), and a capillary tube (20) disposed on the pressure reduction pipe (19).

Therefore, in the beat pump type air conditioner of the fourth embodiment, by closing the throttle means (7) when the heating operation is stopped, it is possible to suppress the refrigerant from entering the refrigerating machine oil. In addition, during the defrost operation period, the inverter (24) sets the motor (23) to a frequency with large heat loss, and the refrigerating machine oil is heated by the heat generated by the motor (23), so the refrigerant flows into the refrigerating machine oil. The zeta defrost operation can be carried out efficiently by suppressing melt penetration.

As a result, it is possible to prevent the device from starting up while asleep, and it is also possible to rapidly increase the temperature in the room. In this fourth embodiment as well, the discharge pressure and suction pressure of the compression 1 liter (1) change as shown in FIG. 4, as in the second embodiment.

[Effects of the Invention] As detailed above, the heat pump air conditioner of the present invention described in claim 1 includes a compressor, a four-way valve that can be switched to a heating position and a cooling position, and a four-way valve that can be switched between a heating position and a cooling position. A check valve that prevents the backflow of refrigerant toward the compressor, a throttle means that can control the opening and is located between the indoor heat exchanger and the outdoor heat exchanger, and a throttle means that is located on the suction side of the compressor. an accumulator,
It consists of an on-off valve disposed on a bypass pipe connecting the accumulator and the discharge side of the compressor.

Therefore, when the heating operation is stopped, the refrigerant is confined in the indoor heat exchanger between the check valve and the throttle means, and it is possible to prevent the refrigerant from entering the refrigerating machine oil due to backflow. In addition, at the start of heating operation, the refrigerant discharged from the compressor circulates through the bypass piping and the accumulator.
The refrigerating machine oil in the compressor can be efficiently heated to increase the circulation flow rate of refrigerant, and as a result, the indoor temperature can be rapidly warmed.

The heat pump air conditioner according to claim 2 further includes a compressor, a four-way valve that can be switched between a heating position and a cooling position, and a check valve that prevents the refrigerant from flowing backward from the four-way valve toward the compressor. , a throttle means that can control the opening degree arranged between the indoor heat exchanger and the outdoor heat exchanger, an accumulator arranged on the suction side of the compressor, and a heater that heats the refrigerating machine oil in the compressor. It is composed of Therefore, similarly to the invention of claim 1, it is possible to suppress the refrigerant from entering the solution when the heating operation is stopped. In addition, by activating the heater a predetermined time before starting heating operation, the refrigerating machine oil in the compressor can be heated in a short time, and as a result, the indoor temperature can be rapidly raised with a high circulating flow rate of refrigerant. can.

Furthermore, the heat pump air conditioner according to claim 3 includes a compressor, a four-way valve that can be switched between a heating position and a cooling position, and a check valve that prevents refrigerant from flowing backward from the four-way valve toward the compressor. , a throttle means that can control the opening degree arranged between the indoor heat exchanger and the outdoor heat exchanger, an accumulator arranged on the suction side of the compressor, and a heater that heats the refrigerating machine oil in the compressor. , a defrost on-off valve disposed on the defrost piping, and a capillary tube disposed on the pressure reducing piping. Therefore, similarly to the first aspect, it is possible to suppress the refrigerant from entering the solution when the heating operation is stopped. Further, since the heater is operated during a period from a predetermined time before the start of the defrost operation until the end of the defrost operation, the defrost operation can be performed efficiently in a short time. As a result, the start-up performance of the heating operation is improved, and the room can be rapidly heated.

The heat pump type air conditioner according to claim 4 includes a compressor with a built-in motor, an inverter that changes the frequency of the motor, a four-way valve that can be switched to a heating position and a cooling position, and a compressor that compresses air from the four-way valve. A check valve that prevents the backflow of refrigerant toward the compressor, a throttle means that can control the opening and is located between the indoor heat exchanger and the outdoor heat exchanger, and a throttle means that is located on the suction side of the compressor. It consists of an accumulator, a defrost on-off valve disposed on the defrost piping, and a capillary tube disposed on the pressure reducing piping. Therefore, similarly to the first aspect, it is possible to suppress the refrigerant from entering the solution when the heating operation is stopped.

Also, during the defrost operation period, the motor is driven by the inverter at a frequency with a large heat loss.
Since the refrigerating machine oil is heated by the heat generated by the motor, efficient defrost operation can be performed with a simple configuration.

As a result, the start-up performance of the heating operation can be improved and the room can be rapidly heated.

[Brief explanation of the drawing]

Fig. 1 is a refrigerant circuit diagram of a heat pump air conditioner according to the first embodiment of the present invention, and Fig. 2 shows the temporal changes in the discharge pressure and suction pressure of the compressor in the refrigerant circuit of Fig. 1 compared to the conventional one. FIG. 3 is a refrigerant circuit diagram of a heat pump air conditioner according to the second embodiment of the present invention, and FIG. 4 is a characteristic diagram showing the relationship between the discharge pressure and suction pressure of the compressor in the refrigerant circuit of FIG. Fig. 5 is a refrigerant circuit diagram of a heat pump type air conditioner according to the third embodiment of the present invention, and Fig. 6 is a refrigerant circuit diagram of a heat pump type air conditioner according to the fourth embodiment of the present invention. Refrigerant circuit diagram of air conditioner FIG. 7 is a refrigerant circuit diagram showing a conventional heat pump type air conditioner. In the figure: 1: Compressor 3: Check valve 5: Indoor heat exchanger 7: Throttling means 9: Accumulator 11: Bypass piping 15: Heater 2: Four-way valve 4: Discharge piping 6: Outdoor heat exchanger 8: Refrigerant piping 10: Suction piping 12: On-off valve 17: Defrost piping 18: Defrost on-off valve 19: Depressurization piping 20: Capillary tube 23: Motor 24: Inverter. In the drawings, the same reference numerals and the same symbols indicate the same or equivalent parts. Agent: Patent attorney Masuo Odai and two others: Compressor 4: Discharge piping 7: Throttle means 5 Figure 17: Defrost piping Figure 6 23: Motor

Claims (4)

[Claims] (1) A compressor that receives external power to compress refrigerant; a four-way valve that is connected to the discharge side of the compressor and can be switched between a heating position and a cooling position; and a compressor that compresses refrigerant from the four-way valve to the compressor. a check valve that prevents backflow; an indoor heat exchanger to which refrigerant is supplied from the compressor through a four-way valve in a heating position; and an outdoor heat exchanger to which refrigerant is supplied from the compressor through a four-way valve in a cooling position. a heat exchanger; an opening controllable throttle means disposed between the indoor heat exchanger and the outdoor heat exchanger; an accumulator disposed on the suction side of the compressor; and a suction side of the accumulator. 1. A heat pump air conditioner characterized by comprising an on-off valve disposed on bypass piping connecting the side and the discharge side of the compressor. (2) a compressor that compresses refrigerant using external power; a four-way valve that is connected to the discharge side of the compressor and can be switched between a heating position and a cooling position; and a compressor that compresses refrigerant from the four-way valve to the compressor. a check valve that prevents backflow; an indoor heat exchanger to which refrigerant is supplied from the compressor through a four-way valve in a heating position; and an outdoor heat exchanger to which refrigerant is supplied from the compressor through a four-way valve in a cooling position. a heat exchanger; an opening-controllable throttle means disposed between the indoor heat exchanger and the outdoor heat exchanger; an accumulator disposed on the suction side of the compressor; A heat pump air conditioner characterized by comprising a heater that heats refrigerating machine oil. (3) a compressor that compresses refrigerant using external power; a four-way valve that is connected to the discharge side of the compressor and can be switched between a heating position and a cooling position; and a compressor that compresses refrigerant from the four-way valve to the compressor. a check valve that prevents backflow; an indoor heat exchanger to which refrigerant is supplied from the compressor through a four-way valve in a heating position; and an outdoor heat exchanger to which refrigerant is supplied from the compressor through a four-way valve in a cooling position. a heat exchanger; an opening-controllable throttle means disposed between the indoor heat exchanger and the outdoor heat exchanger; an accumulator disposed on the suction side of the compressor; a heater that heats refrigerating machine oil; an on-off valve disposed on a defrost pipe that connects the discharge side of the compressor and the refrigerant pipe between the outdoor heat exchanger and the throttling means; a discharge side of the on-off valve; A heat pump air conditioner comprising: a capillary tube disposed on a decompression pipe connecting the accumulator. (4) a compressor with a built-in motor that obtains power, an inverter that changes the frequency of the motor, a four-way valve that is connected to the discharge side of the compressor and can be switched between a heating position and a cooling position; and from the four-way valve. a check valve that prevents refrigerant from flowing backwards toward the compressor; an indoor heat exchanger to which refrigerant is supplied from the compressor through the four-way valve in the heating position; and an indoor heat exchanger to which the refrigerant is supplied from the compressor through the four-way valve in the cooling position. an outdoor heat exchanger to which refrigerant is supplied; a throttle means that can control the opening degree and is disposed between the indoor heat exchanger and the outdoor heat exchanger; and an accumulator that is disposed on the suction side of the compressor. and a defrost on-off valve disposed on a defrost pipe connecting the discharge side of the compressor and the refrigerant pipe between the outdoor heat exchanger and the throttling means, and a discharge side of the defrost on-off valve and the accumulator. A heat pump type air conditioner characterized by comprising a capillary tube arranged on a connected decompression pipe.