JPH0367960A - Air conditioner - Google Patents

Abstract

PURPOSE:To prevent overheating and accelerated wear-out of cylinders during capacity control operation by a method wherein an on-off valve, which opens and closes a liquid refrigerant supply circuit, is opened during capacity control operation by means of closing refrigerant suction passages of cylinders of a multiple-cylinder compressor, and closed during stoppage of the multiple-cylinder compressor. CONSTITUTION:During capacity control operation of a multiple-cylinder compressor 1 by means of cylinder unloading, a solenoid on-off valve 31 is opened in connection with the operation of the multiple-cylinder compressor 1, and the liquid refrigerant is fed from a feeding port 30a to a second cylinder 1b through a liquid refrigerant supply circuit 29 so that lubrication is maintained by the refrigerating machine oil contained in the refrigerant. As a result, heating inside the second cylinder 1b is controlled and accelerated wear-out is prevented by the liquid refrigerant flowing into it. When the multiple-cylinder compressor 1 which has been out of operation is started, the solenoid on-off valve 31 provided on the liquid refrigerant supply circuit 29 is opened a specified time period after the compressor 1 is started, so that the refrigerant and the refrigerating machine oil are prevented from flowing outside the multiple- cylinder compressor 1 from the feeding port 30a through the liquid refrigerant supply circuit 29.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air conditioner that performs capacity control by controlling the opening and closing of refrigerant suction passages to the cylinders of a multi-cylinder compressor.

[Conventional technology]

FIG. 6 is a refrigerant circuit diagram showing a conventional air conditioner.

In the figure, (1) is the first cylinder (1a) with the same capacity.
This is a multi-cylinder compressor consisting of a high-pressure shell type two-cylinder rotary compressor that is driven by one motor (2) and compresses a gas refrigerant. The first cylinder (1a) and the second cylinder
It is cooled by refrigerant gas discharged from the cylinder (lb). (3) indicates the direction of the solid line when the refrigerant circuit is in cooling operation;
In the case of heating, a four-way switching valve that switches in the direction of the dotted line, (the main is the outdoor heat exchanger (4a), the blower! 51, and the check valve (7)
) are connected in parallel expansion 11! an outdoor heat exchanger equipped with an oval (6); (12) is a first indoor heat exchanger (12);
a), a first chamber (1) equipped with an expansion mechanism (8) in which a blower (13) and a check valve (9) are connected in parallel; (15) is a side heat exchange device; indoor heat exchanger (15
(16) is an accumulator, and (16) is an accumulator; (16
) are connected by refrigerant piping to form a refrigeration cycle.

(+7) (+8) is an electromagnetic on-off valve connected to the inlet side of the first and second indoor heat exchangers (+2) (15) during cooling operation, and this electromagnetic on-off valve <17) (18) By opening and closing the first and second indoor heat exchange devices (+
2) Control the operation of (15). (19) is a refrigerant suction path consisting of a refrigerant pipe connecting the outlet side of the accumulator (16) and the input side of the multi-cylinder compressor (1), and this refrigerant suction path (19) is connected to the first cylinder. A refrigerant suction passage (19a) that communicates with the second cylinder (1b) via an on-off valve (20) (
22) It is divided into two parts. (23) and (24) are electromagnetic on-off valves connected in series, and the above electromagnetic on-off valve (23)
is connected to the refrigerant suction path (21) of the second cylinder'' (1b) of the multiple cylinder compressor (1) through the refrigerant pipe (25), and the electromagnetic on-off valve (24) is connected to the refrigerant suction path (21) of the second cylinder'' (1b) of the multiple cylinder compressor (1) through the refrigerant pipe (26). fi (connected to the discharge side of 11. The series connection point of the electromagnetic on-off valve (23) and the electromagnetic on-off valve (24) is connected to the electromagnetic on-off valve (20) through a refrigerant pipe (27). There is.

FIGS. 8 and 7 are longitudinal sections of the on-off valve (20).

In the figure, (20b) is formed on the side surface of the on-off valve body (20a), and is a first coupling hole connecting the refrigerant suction passage (21), and <20c) is formed on the upper end of the on-off valve body (20a). a second coupling hole connecting the refrigerant suction path (22), (
20d) is formed at the lower end of the on-off valve body (20a),
There is a third coupling hole that connects the refrigerant pipe (27), and these first coupling hole (20b) to third coupling hole (20d) communicate with each other through a communication hole (20e). (2Of) slides in the communication hole (20e) and connects to the first coupling hole (20e).
a slider that opens and closes communication between b) and the second coupling hole (20c) and closes communication between the first and second coupling holes (20b) (20c) and the third coupling hole (20d'l); The on-off valve (20) is configured as described above, and for example, when the compression 1 fl] is in operation, the solenoid on-off valve (24) in Fig. 6 is closed and the solenoid on-off valve (23) is open. ,
The refrigerant pipe (27) and the refrigerant suction passage (21) are electrically connected through the electromagnetic on-off valve (23) (3) (4), and the refrigerant pipe (
The pressure inside the 27L refrigerant suction passage (21) is equal to the pressure inside the refrigerant suction passage (22
), the slider (2Of) is pushed down by the flow of the refrigerant as shown in Figure 8, and the first and second coupling holes (20b) (20c) are brought into conduction and the refrigerant flows through the first
and the second cylinder (Ia) (lb), and the multi-cylinder compressor (1) is in full operation at 100% capacity.

Also, when the multiple cylinder compressor (1) is in operation, the electromagnetic on-off valve (
24) is opened and the electromagnetic on-off valve (23) is closed, the pressure in the refrigerant pipe (27) becomes the same as the discharge pressure, and the refrigerant suction passage (
22) becomes higher than the pressure at slider (20f)
is pushed up as shown in Figure 7, the flow of refrigerant to the second cylinder (1b) is closed, and the multi-cylinder compressor (]) is supplied with refrigerant only to the first cylinder (1a). , the cylinder will be operated at 50% capacity.

Since conventional air conditioners were configured as described above, for example, during cooling operation and defrost I operation, high-temperature and high-pressure refrigerant discharged from the multiple cylinder compressor (1) is passed through the four-way switching valve (3). It is then sent to the outdoor heat exchanger (4), where it exchanges heat with the air sent from the blower (5) and is liquefied here. Next, this liquefied refrigerant, that is, the liquid refrigerant, is depressurized by a check valve (gamma, an electromagnetic on-off valve (171 (+8), and an expansion mechanism +8) 00), and then transferred to the indoor heat exchanger (12).
At (15), it exchanges heat with the air sent from the blower (+3) (+4) and is vaporized again. After the vaporized refrigerant passes through the four-way switching valve (31) and the accumulator (16), one side goes through the refrigerant suction passage (19) (+9a) to the first cylinder (1a), and the other side goes through the refrigerant suction passage (19) (+9a), and the other side goes through the four-way switching valve (31) and the accumulator (16). Solenoid on-off valve (23) (1,7) (+8) is open, solenoid on-off valve (2
4) is sucked into the second cylinder (l b ) through the refrigerant suction path <19) (22), the opening/closing valve (20>), and the refrigerant suction path (21) when closed.

During cylinder operation, that is, when one of the solenoid on-off valves (+7) (+8) is open and the other is closed, the solenoid on-off valve (24) is open, and the solenoid on-off valve (23) is closed, the on-off valve (20 ) The circuit from the refrigerant suction passage (22) to the refrigerant suction passage (21) is closed by the slider (2Of), so the refrigerant is not supplied to the second cylinder (1b) and the first cylinder < 1a) only. In this way, a refrigeration cycle is formed.

Further, during heating operation, the refrigerant circuit is switched in the direction of the dotted line by the four-way switching valves (5) (6) (3), and the refrigerant flows in the direction shown by the dotted arrow. i.e. multiple cylinder compressor (1)
The high-temperature, high-pressure refrigerant discharged from the 4-way switching valve (3) is sent to the indoor heat exchanger (12), (151), where it exchanges heat with the air sent from the blower (+3) (14). Next, during full operation, this liquefied refrigerant, that is, liquid refrigerant, passes through the check valve (91 (II)) and the electromagnetic on-off valve (+7) (+8) to expand (8!). 6)
The pressure is reduced. The depressurized refrigerant is transferred to the outdoor exchanger (4a)
It exchanges heat with the air sent from the blower (5) and is vaporized again.

The vaporized refrigerant is transferred through a four-way switching valve (31,
16), one side is the refrigerant suction passage (+9) (1
9a) to the first cylinder (la), and the other side is the refrigerant suction passage (19) (22), and the on-off valve (20L) to the second cylinder (1b) through the refrigerant suction passage (21). During cylinder operation, the slider (20) of the on-off valve (20)
f) from the refrigerant suction passage (22) to the refrigerant suction passage (21).
) is closed, so that the refrigerant is not supplied to the second cylinder <Ib), but only to the first cylinder (1a).

In this way, a refrigeration cycle is formed.

[Problem to be solved by the invention]

In the above-mentioned air conditioner, when the refrigerant suction path is closed during capacity control operation using the cylinder, refrigerant is not supplied to the cylinder whose refrigerant suction path is closed, so the refrigerating machine oil circulating in the refrigerant is However, since the cylinders are driven by the motor in this state, there is a problem in that the wear of the cylinders is accelerated and the life of the multiple cylinder compressor is significantly shortened. Furthermore, during capacity control operation using the body cylinders, as described above, the cylinders are driven by the motor without being supplied with refrigerant, so the pressure inside the cylinders decreases and the high-temperature, high-pressure refrigerant gas in the multi-cylinder compressor is reduced. There is a problem in that the refrigerant gas flows into the cylinder, is recompressed, becomes high temperature and high pressure refrigerant gas, heats the cylinder, accelerates wear, and significantly shortens the life of the multiple cylinder compressor.

This invention was made to solve this problem. During capacity control operation by closing the refrigerant suction passage, in cylinders to which refrigerant is not supplied, the capacity is increased without promoting excessive heat and wear. The purpose is to provide an air conditioner that can be operated in a controlled manner.

[Means to solve the problem]

In the air conditioner according to the present invention, liquid refrigerant is supplied, which is condensed in either the first or second heat exchanger, to the refrigerant suction side of a predetermined cylinder whose refrigerant suction circuit is controlled to open and close. a circuit, an on-off valve for controlling the opening and closing of the liquid refrigerant supply circuit, and after a predetermined period of time after starting the multiple cylinder compressor, the on-off valve is opened during capacity control operation by closing at least the refrigerant suction circuit; The compressor is equipped with an on-off valve control device that controls the on-off valve to close while the multiple cylinder compressor is stopped.

[For production]

In this invention, the on-off valve that opens and closes the liquid refrigerant supply circuit that supplies liquid refrigerant to the predetermined cylinders whose refrigerant suction passages are controlled to open and close is operated after a predetermined period of time has elapsed since the start-up of the multi-cylinder compressor, at least in the cylinders. The opening/closing control is performed so that it opens during capacity control operation by closing the refrigerant suction passage, and closes when the multiple cylinder compressor is stopped.

〔Example〕

FIG. 1 is a refrigerant circuit diagram of an air conditioner showing an embodiment of the present invention. In FIG. 1, fl] to (27) indicate the same or equivalent parts as those of the conventional air conditioner described above, and therefore the explanation thereof will be omitted. (28) is the outdoor heat exchanger (4
) and the first and second indoor heat exchange devices <12) (15)
A liquid pipe (29) consisting of a refrigerant pipe connecting between the liquid pipe (28) and an inlet (30a) opening into the refrigerant suction chamber of the second cylinder (1b) of the multi-cylinder compressor (1)
(31) is an electromagnetic on-off valve that opens and closes the two liquid refrigerant supply circuits; (32) is an electromagnetic on-off valve that controls opening and closing of the electromagnetic on-off valve (31) and a multi-cylinder compressor (1); ) is an equipment operation determining device that controls the start and stop of the equipment.

FIG. 2 is a block diagram showing an embodiment of the device operation determining device. In Fig. 2, (33) is a selection circuit that selects whether to operate or stop the air conditioner, and (34) is a selection circuit that selects whether to operate or stop the air conditioner, and (34) which operates the multiple cylinder compressor (1) according to the operation or stop output signal of the selection circuit (33). (10) An electromagnetic switch for starting and stopping control, (35) is a timer counter.

FIG. 3 is a cross-sectional view of the second cylinder (Ib) of the multiple cylinder compressor (1). In FIG. 3, the upper end surface side of the second cylinder <lb) is the first cylinder <1a
) and the second cylinder (lb) is airtightly provided with a partition plate (not shown), and a lower bearing (30
) is installed in an airtight manner. (lb-1) is the cylinder wall of the second cylinder (1b), (41) is the drive shaft (41a) that is connected to the motor (2) and rotates in the direction of the solid arrow
> is an eccentric portion formed integrally with the drive shaft (4I), (
42) is a rolling piston fitted into the eccentric portion (41a), (43) is a component of the cylinder wall (Ib-1), the rolling piston (42), the partition plate (not shown), and the lower bearing ( A cylinder chamber (44) surrounds the cylinder chamber (43) with a compression chamber (30).
43a) and the refrigerant suction chamber (43b), and the tip of the vane (44) is pressed against the outer periphery of the rolling piston (42) by a spring (not shown). 42) as the vane groove (
4, 4a) Slide inside. (45) is a refrigerant suction port provided in the cylinder wall <Ib1) and opening into the refrigerant suction chamber (43b), which constitutes the refrigerant suction path (21). (30a) is an injection port provided in the lower bearing (30) and opening into the refrigerant suction chamber (43b);
It is connected to the liquid refrigerant supply circuit (29), and liquid refrigerant is supplied from the liquid refrigerant supply circuit (29). (46) is the compression chamber (
43a) is a discharge port through which the compressed refrigerant is discharged.

Next, the operation of the air conditioner configured as described above is explained in the fourth step.
This will be explained with reference to the figures. FIG. 4 is a flowchart 1 explaining the operation of the device operation determination device. First, when the selection circuit (33) constituting the equipment operation determining device (32) selects the operation of the air conditioner (step (36)), an operation signal is output from the selection circuit (33), and this operation signal The electromagnetic switch (34) closes, power is supplied to the multiple cylinder compressor (1), and the multiple cylinder compressor (1)
is activated (step (37)).

On the other hand, when the multiple cylinder compressor (1) starts, the timer counter (35) starts counting time at the same time as this startup, and the timer counter (35) starts counting time for a preset predetermined time, that is, the multiple cylinder compressor (1) starts and the liquid pipe (28 ) increases to a pressure equivalent to the discharge pressure of the multiple cylinder compressor (1) (11), and the pressure of the second cylinder (1) of the multiple cylinder compressor (1) increases.
After a predetermined period of time has elapsed until the pressure becomes higher than the pressure at the injection port (30a) in b), the count is increased and the electromagnetic on-off valve (
31) to open (step (39)). Solenoid on-off valve (
31) through the liquid refrigerant supply circuit (29),
High-pressure liquid refrigerant is condensed in the outdoor heat exchanger (4a) during cooling operation, and in the first and second heat exchangers <12a) (15a) during heating operation, and is condensed in the multiple cylinder compressor (15a). ) The injection port (30a) provided in the second cylinder (1b) of
supplied to

In the second cylinder (1b), the cylinder chamber (43
) is partitioned by a vane (44) into a compression chamber (43a) and a refrigerant suction chamber <4.3b), and this partitioned refrigerant suction chamber (43b) has a refrigerant suction port (45) and an injection port (30a). sucks refrigerant from. The drive shaft (44) rotates in the direction of the solid arrow due to the force of the motor (22), and the rolling piston (42) also rotates, thereby compressing the refrigerant in the compression chamber (43a) and discharging it. It is discharged from the outlet (46).

(12) Therefore, when the multi-cylinder compressor (1) is in capacity control operation using the cylinders, when refrigerant is not supplied to the refrigerant suction port (45) of the second cylinder (1b) through the refrigerant suction passage (21), Also, by opening the electromagnetic on-off valve (31) in conjunction with the operation of the multi-cylinder compressor (1), the liquid refrigerant is transferred from the inlet (30a) to the second cylinder (Ib) through the liquid refrigerant supply circuit (two). Since the liquid refrigerant is injected, lubrication is ensured by the refrigerating machine oil contained in the liquid refrigerant, and heating inside the second cylinder (1b) is suppressed by the inflow of the liquid refrigerant, thereby preventing acceleration of wear.

In addition, the second
Although the amount of liquid refrigerant supplied to the second cylinder (1b) is relatively small, the liquid refrigerant supplied to the second cylinder (lb) becomes a low-pressure, low-temperature liquid refrigerant and is sucked through the refrigerant suction port (45). Since the temperature of the refrigerant is lowered, it is possible to suppress an excessive rise in the discharge gas temperature of the multiple cylinder compressor (1) during full operation.

Furthermore, when the stopped multi-cylinder compressor (1) starts, the pressure in the liquid pipe (28) rises to the same pressure as the discharge pressure of the multi-cylinder compressor (1), and the second cylinder compressor (13) (14) After startup until the pressure in the refrigerant suction chamber (43b) of the ring (Ibl) decreases and the pressure in the liquid pipe (28) becomes higher than the pressure in the refrigerant suction chamber (43b) of the second cylinder (lb). For a predetermined period of time, the refrigerant and the refrigerating machine oil contained therein try to flow out from the second cylinder (1b) by the rotating rolling piston (42).
) starts to rise from the pressure at the time of suction and rises to a pressure lower than the discharge pressure, depending on the rotation of the rolling piston (42) and its position. For example, suction pressure 4 kg
/c1112, if the discharge pressure is 18kg/c+n2, 1
Since the pressure in the liquid pipe (28) does not rise to 10 kg/c+n2 or more, the compressor (
Refrigerant and refrigerator oil will flow out from 1). Therefore, the electromagnetic on-off valve (31) provided in the liquid refrigerant supply circuit (29)
) for multiple cylinder pressures 1i! The liquid refrigerant supply circuit (29
) can prevent refrigerant and refrigerating machine oil from leaking to the outside of the multiple cylinder compression fi (11).

Also, when the operating multi-cylinder compressor (1) stops, the refrigerant in the second cylinder (1b) immediately after the stop is
The temperature rises to the saturation pressure, and in order to balance the pressure, the refrigerant and the refrigerating machine oil contained in it try to flow out from the second cylinder (1b). By closing the on-off valve (31) in conjunction with the stop of the multiple cylinder compressor (1), refrigerant is supplied to the outside of the multiple cylinder compressor (1) from the inlet (30a) through the liquid refrigerant supply circuit (29). and can prevent refrigerating machine oil from flowing out.

In addition, when the multiple cylinder compressor (1) is stopped, if the multiple cylinder compressor fi (1) is located at a lower position than the liquid pipe (28), or due to the influence of the ambient temperature, the multiple cylinder compressor When the pressure inside the compressor (1) is lower than the pressure in the liquid pipe (28), the liquid refrigerant in the liquid pipe (28) tries to flow into the multi-cylinder compressor (1), but the liquid refrigerant supply By closing the electromagnetic on-off valve (31) provided in the circuit (29) in conjunction with the operation of the multi-cylinder compressor (1), the liquid refrigerant supply circuit (two) and the injection port are connected to the liquid pipe (28). (30) can prevent liquid refrigerant from flowing into the multi-cylinder compressor (1).

(15> (16) In the above embodiment, the liquid refrigerant supply circuit (29) is connected from the liquid pipe (28) of the refrigerant circuit to the refrigerant suction chamber (43b) of the second cylinder (1h) corresponding to the on-off valve (20). ), but it may be connected to any refrigerant suction side of the second cylinder (1b), for example, a refrigerant suction path formed between the on-off valve (20) and the second cylinder (1b). Similar effects can be obtained by connecting to (21).

Moreover, in the above embodiment, the device operation determination device! (32)
opens the electromagnetic on-off valve (31) after a predetermined time from the startup of the multiple cylinder compressor (1), but the equipment operation determining device (32) opens the above-mentioned predetermined time from the startup of the multiple cylinder compressor fi The electromagnetic on-off valve (31) may be opened later and only during capacity control operation using the body cylinder. A block diagram of an embodiment of this device operation determining device (32) is shown in FIG. The difference in Fig. 5 from Fig. 3 is that the timer counter (35) counts up and outputs the open signal of the electromagnetic on-off valve (31) after a predetermined period of time, and the output signal of the electromagnetic on-off valve (31) outputs from the selection time 1\8 (33). Both signals, including the cylinder capacity control operation signal, are input into an AND circuit (46), and the electromagnetic on-off valve (31) is controlled to open and close by ANDing the two signals.

Furthermore, in the above embodiments, an air conditioner using a high-pressure shell type two-cylinder rotary compressor that cools the compressor motor with gas refrigerant after compression has been described. Low pressure shell type 2 that cools
It may also be a cylinder rotary compressor. Moreover, a multiple cylinder compressor having two or more cylinders may be used.

〔Effect of the invention〕

This invention includes a liquid refrigerant supply circuit that supplies liquid refrigerant condensed in either the first or second heat exchanger constituting the refrigeration cycle to the refrigerant suction side of a cylinder whose refrigerant suction passage is controlled to open and close. , after a predetermined period of time from the startup of the multiple cylinder compressor, at least during capacity control operation by closing the refrigerant suction passage, an on-off valve for opening and closing the liquid refrigerant supply circuit is opened, and closed while the multiple cylinder compressor is stopped. With this configuration, liquid refrigerant is supplied to the cylinder whose refrigerant suction passage is closed during the capacity control operation, and the refrigerating machine oil contained in the liquid refrigerant prevents overheating of the cylinder and acceleration of wear (17) (18). , and immediately after starting and stopping the multiple cylinder compressor, the refrigerant and refrigerating machine oil are prevented from flowing out from the multiple cylinder compressor to the liquid pipe side via the liquid refrigerant supply circuit, and the multiple cylinder pressure li is prevented.
Liquid refrigerant is prevented from flowing into the multiple cylinder compressor from the liquid pipe through the liquid refrigerant supply circuit during machine stoppage, and the reliability of the air conditioner is improved.

[Brief explanation of drawings]

Fig. 1 is a refrigerant circuit diagram of an air conditioner showing an embodiment of the present invention, Fig. 2 is a block diagram showing an embodiment of the equipment operation determining device, and Fig. 3 is a refrigerant circuit diagram showing an embodiment of the device operation determining device. FIG. 4 is a flowchart 1 to 1 showing the operation of the device operation determining device, FIG. 5 is a block diagram showing another embodiment of the device operation determining device, and FIG. 6 is a flowchart showing the operation of the device operation determining device. The refrigerant circuit diagrams, FIGS. 7 and 8 are longitudinal sectional views showing the detailed structure of the on-off valve shown in FIG. 6. In the figure, (28) is a liquid pipe, (29) is a liquid refrigerant supply circuit, (30) is an inlet, (31) is an electromagnetic shut-off valve, and (32) is a liquid refrigerant supply circuit.
) is an equipment operation determining device. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A refrigeration cycle configured by sequentially connecting a plurality of cylinder compressors having a plurality of cylinders, a four-way switching valve, a first heat exchanger, an expansion mechanism, and a second heat exchanger through refrigerant piping, Capacity control is performed by controlling opening and closing of a refrigerant suction passage to a predetermined cylinder of a multi-cylinder compressor, in which the liquid refrigerant condensed in either the first or second heat exchanger is transferred to the predetermined cylinder. a liquid refrigerant supply circuit that supplies the refrigerant to the refrigerant suction side of the cylinder, an on-off valve that opens and closes the liquid refrigerant supply circuit, and a predetermined period of time after the activation of the multi-cylinder compressor, at least due to the closing of the refrigerant suction passage. An air conditioner comprising an on-off valve control device that controls opening and closing of the on-off valve so that the on-off valve is opened during capacity control operation and closed when the multiple cylinder compressor is stopped.