JPS5924153A - Heat pump type refrigeration cycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump type refrigeration cycle.

In a conventional heat pump type refrigeration cycle, as shown in FIG. 1, a compressor 1. Four-way valve 2. Outdoor heat exchanger 3. The expansion device 4 and the indoor heat exchanger 5 are sequentially connected in an annular manner, and during cooling operation, the high temperature and high pressure refrigerant scum from the compressor I is sent to the outdoor heat exchanger 3 as shown by the solid line arrow, where it is condensed. It is evaporated in the indoor heat exchanger 5 via the expansion device 4, and during heating operation, the high-temperature, high-pressure refrigerant scum from the compressor I is reversely circulated as shown by the broken line arrow to perform heating.

Generally, in this type of refrigeration cycle, when the pressure haI is stopped, the refrigerant in the cycle flows from the high pressure side to the low pressure side.
Gradually the pressure will balance, but this balancing usually takes 2 to 3 minutes. Further, regarding the restart of the compressor 1, there is a characteristic that if the pressure difference between the discharge side and the suction side is large, it will be difficult to start the compressor 1 and an overcurrent will flow.

Therefore, conventionally, a three-minute delay method has been adopted for safety.

However, in such a refrigeration cycle, if there is a 3-minute delay, even if the room temperature drops below the lower limit of the thermostat due to load conditions, it will not restart if it is within 3 minutes; There was a drawback that the room temperature deviated significantly from the set temperature.

Another problem is that when compressor 1 is stopped and restarted from a pressure-balanced state, it takes a certain amount of time to return to the steady pressure state, and during this time, sufficient capacity cannot be obtained and efficiency decreases. There was a drawback to that.

The present invention was made with the aim of eliminating the above two drawbacks, and aims to shorten the pressure lance time when the compressor is stopped, and shorten the rise time when the compressor is restarted. It provides a heat pump type refrigeration cycle.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Fig. 2 is a refrigerant circuit diagram of the heat pump refrigeration cycle according to the present invention, Fig. 3 is an explanatory diagram of the operation of the compressor and the first to fifth solenoid valves in the refrigeration cycle during cooling, and Fig. 4 is the heating FIG.

Note that solid arrows indicate the flow of refrigerant during cooling operation, thick lines indicate when the compressor is operating, and thin lines indicate when the compressor is stopped. Moreover, the broken line arrow indicates the flow of refrigerant during heating operation, the thick line indicates when the compressor is operating, and the thin line indicates when the compressor is stopped.

In FIG. 2, 11 is a compressor for compressing refrigerant gas, and one end of an outdoor heat exchanger 13 is connected to one end opening of the compressor 11 via a first electromagnetic valve 101. At the other end of the compressor 13 there is a fifth valve which is closed when the compressor 11 stops operating.
One end of the indoor heat exchanger 16 is connected to the other end of the indoor heat exchanger 16 through a second solenoid valve 14 and an expansion device 15, and the other end of the compressor 11 is connected to the other end of the indoor heat exchanger 16 through a second solenoid valve 201. Connecting end openings.

And a first bypass flow path that communicates between the flow path between the compressor II and the first solenoid valve +01 and the flow path between the indoor heat exchanger 16 and the second solenoid valve 201! 8, and a third solenoid valve 10 is provided in this first bypass flow path 18.
2, and also communicates the flow path between the first solenoid valve +01 and the outdoor heat exchanger 13 and the flow path between the second solenoid valve 201 and the compressor 11. A passage 19 is provided, and a fourth electromagnetic valve 202 is interposed in this second bypass passage j9.

3 and 4 show the compressor 11 in the heat pump type refrigeration cycle. First solenoid valve-I 01 , second solenoid valve 201 . Third solenoid valve 102. Fourth solenoid valve 202. and the operating state of the fifth solenoid valve 14 during cooling operation and heating operation, and when the compressor 11 is stopped and restarted, each solenoid valve is
It works as shown in the figure. That is, when the compressor 11 is stopped during cooling operation, the fifth solenoid valve 14 is first turned off as shown in FIG.
is closed, the compressor 11 is stopped with a slight delay, and even later, the first solenoid valve LO is closed and the third solenoid valve 102 is opened. In addition, when restarting the operation of the compressor 11, first the compressor 11 starts operation, and
, the third solenoid valve 102 closes, the first solenoid valve 101 opens with a slight delay, and the fifth solenoid valve 14 opens with a further delay.
will be developed. Note that during this cooling operation, the second solenoid valve 2
01 remains open, and the fourth electromagnetic valve 202 remains closed.

When the compressor 11 stops during heating operation, as shown in FIG. When the third solenoid valve 102 closes, the first solenoid valve 101 opens. In addition, when restarting the operation of the compressor 11, first the compressor 1
1, the first solenoid valve 102 closes as soon as operation starts, the third solenoid valve 102 opens with a slight delay, and the fifth solenoid valve 14 opens with a further delay. Note that during this heating operation, the second solenoid valve 201 maintains a closed state, and the fourth solenoid valve 202 maintains an open state.

Next, the operation of the refrigeration cycle will be explained.

First, during the initial cooling operation, the solenoid valve +01,14°20
1 is opened to drive the compressor 11, the high temperature and high pressure refrigerant gas compressed by the compressor 11 flows through the first solenoid valve lot to the outside heat exchanger 13, where it is condensed.
Indoor heat exchanger 1 via solenoid valve 14 and expansion device 15
Sent within 6.

The liquid refrigerant sent to the indoor heat exchanger 16 evaporates within the indoor heat exchanger I6, and at this time takes vaporization heat from the surroundings. After that, the refrigerant residue vaporized in the indoor heat exchanger 16 is returned to the compressor 11 through the second electromagnetic valve 20+. By repeating this operation, the room is cooled to a predetermined humidity by the indoor heat exchanger 16.

When the indoor temperature reaches a predetermined temperature, a thermostat (not shown) operates to first close the solenoid valve I4, then delay to stop the operation of the compressor II, and further delay to close the first solenoid valve I4. The compressor 11 is connected to the compressor 11 through the flow path 18 which is closed by the solenoid valve +01.
The pressure instantly flows to the low pressure side of the compressor 11, and the pressures on the discharge side and suction side of the compressor 11 are balanced. That is, the compressor 11 can be restarted at any time, and there is no need to restart the compressor 11 with a 3-minute delay as in the prior art.

Therefore, detailed control of room temperature is possible.

At this time, if the first solenoid valve +01 is closed before the compressor 11 is stopped, there is a risk that the high-pressure refrigerant side will be overcompressed, so the first solenoid valve +01 is closed after the compressor 11 is stopped. If controlled in this way, the fifth solenoid valve 14 and the first solenoid valve
1 and 7 are held between them.

Thereafter, when the room temperature rises and the thermostat detects this, the compressor 11 is restarted, but the time required for restart differs depending on the magnitude of the cooling load.

Therefore, the holding pressure state of the high-pressure refrigerant held between the first solenoid valve IQ+ and the fifth solenoid valve 14 also differs (i4
'<1. Therefore, if the stop time (time indicated by tc in FIG. 3) is long, the holding pressure will be low, and if the stop time tc is short, the holding pressure will be held high.
If the valve opening/closing timings of the first solenoid valve +01 and the fifth solenoid valve 14 (tel and j (time indicated by 5 in Fig. 3) are always kept constant, there may be the problem of overcompression if the stop is stopped for a short time. - The engine will operate in a less efficient state when restarting.

Therefore, the present invention temporally controls the valve opening/closing timings tel and tc5 by integrating the stop time [C, thereby constantly performing restart operation in an efficient state.

In other words, the opening timing te of the first solenoid valve 101 and the fifth solenoid valve I4 depends on the stop time tc of the compressor 11.
l and tc5 are determined, and when tc1 time elapses after the restart of the compressor 11, the conduit to the first solenoid valve 101 reaches a predetermined pressure and the first solenoid valve 101 is opened, and the compressor When tc5 hours have elapsed after the restart of No. 11, the pressure in the pipeline up to the fifth solenoid valve 14 reaches a predetermined pressure, and the fifth solenoid valve 14 is opened. be.

Next, heating operation will be explained. During heating operation, the third solenoid valve +02 and the fourth solenoid valve 202 are opened,
1st. The third solenoid valve 101, 201 is closed and the compressor 1
In this way, the refrigerant gas from the compressor 11 is transferred to the third solenoid valve 102. It flows through the first bypass passage 18 to the indoor heat exchanger 16 , where it is condensed, and then fed to the outdoor heat exchanger 13 through the expansion device 15 and the fifth electromagnetic valve 14 . That is, the indoor heat exchanger 16 acts as a condenser. The outdoor heat exchanger 13 then acts as an evaporator. and outdoor heat exchanger 1
The refrigerant gas evaporated in step 3 is returned to the compressor 11 through the second bypass passage I9 and the fourth solenoid valve 202.

After that, when the indoor temperature reaches a predetermined humidity due to the action of the indoor heat exchanger I6, the thermostat is activated and first the fifth solenoid valve 14 is stopped, and then the operation of the compressor 11 is stopped with a delay, and then the operation of the compressor 11 is stopped. The third solenoid valve 102 closes with a delay. At this time, the first solenoid valve IQ+ is switched to open, and the high-pressure refrigerant gas in the compressor 11 is passed through the first solenoid valve 101 and the second bypass passage 19 to a low pressure in the same way as in the cooling operation described above. The high-pressure refrigerant in the indoor heat exchanger 16 is maintained as it is while the pressure is balanced.

That is, the discharge and suction pressures of the compressor 11 are controlled by the first solenoid valve 101.
This action instantly balances the engine, allowing it to be restarted at any time.

When restarting, the compressor 11 is first started in the same manner as during cooling, and the first solenoid valve +01 is switched at the same time (may be delayed). Thereafter, after the compressor 11 is restarted based on the cumulative result of the stop time th of the compressor 11, th3
When the time elapses, the third solenoid valve 102 switches, and
When time s has elapsed, the fifth solenoid valve 14 is switched to enter normal heating operation.

In addition, at this time, the indoor fan shall be stopped or brought into a light breeze state to suppress the drop in high pressure due to heat exchange with the indoor temperature. Even if this is done, the indoor temperature will not drop suddenly like in the conventional case.

As described above, efficient operation can be achieved even during heating operation.

Generally, in the case of heating operation, the heating load is large, so the indoor temperature drops significantly during the 3 minute delay time after the compressor 11 stops, and the room temperature fluctuation range becomes wide, causing discomfort. With the configuration of the present invention, the room temperature can be reliably adjusted within the control range of the thermostat without compromising comfort.

Note that the same effect can be obtained even if the fifth solenoid valve 14 is inserted between the expansion device 15 and the indoor heat exchanger 16.

According to the present invention, the indoor temperature can be reliably adjusted within the range of thermostat control without sacrificing comfort, and the start-up time when restarting the compressor can be greatly shortened. In addition, when restarting the compressor, the valve opening/closing timing of the solenoid valve is controlled by integrating the compressor stop time, so restart operation is always performed in an efficient state.Figure 1 shows a conventional heat pump. A refrigerant circuit diagram of a type refrigeration cycle, FIG. 2 is a heat pump according to the present invention.

Refrigerant circuit diagram of a type refrigeration cycle, Figure 3 FIG. 4 is an explanatory diagram of the operation of the compressor and the first to fifth electromagnetic valves during cooling during the cycle, and FIG.

11: Compressor, 13: Outdoor heat exchanger, 14: Fifth electromagnetic valve, 15: Expansion device, 16: Indoor (1111 exchanger, 18: First 7.a, <S flow path, 19: second bypass flow path, giant 1: first solenoid valve, +02: third solenoid valve, 201° second solenoid 4 to, 202, fourth solenoid valve.

Claims (1)

[Claims] 1. A compressor, a first solenoid valve, an outdoor heat exchanger, an expansion device, an indoor heat exchanger, and a second solenoid valve are sequentially connected in an annular manner,
A first bypass flow path is provided that communicates a flow path between the compressor and the first solenoid valve and a flow path between the outdoor heat exchanger and the second solenoid valve; A second bypass flow path is provided that communicates the flow path between the outdoor heat exchanger and the flow path between the second solenoid valve and the compressor, and a third solenoid valve is provided in the first bypass flow path; In a heat pump refrigeration cycle in which a fourth solenoid valve is provided in the second bypass flow path and a fifth solenoid valve is provided between the outdoor heat exchanger and the indoor heat exchanger, compression is performed using a thermostand or the like. A heat pump type refrigeration cycle characterized by integrating the compressor stop time when the machine is stopped and controlling the opening/closing timing of the solenoid valve based on this result.