JPS59217460A - Refrigeration cycle of air conditioner - 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 separate air conditioner (one-pump type air conditioner (hole refrigeration cycle) having an indoor side unit and an outdoor side unit).

Conventionally, there has been a refrigeration cycle for an air conditioner as described above, as shown in FIG.

In Fig. 1, 1 is the pressure mfii, 2 is the four-way valve, 3 is the outdoor heat exchanger, 4 is the distributor, 5 is the expansion valve, 6 is the connecting pipe, 7 is the indoor heat exchanger, 8 is the connecting pipe,
Reference numeral 9 denotes an accumulator, which is provided in at least the indoor heat exchanger 7 or the indoor unit in the separate air conditioning system, and each member not provided in the indoor unit 7) is provided in the outdoor unit 1.

In such a refrigeration cycle, during cooling operation of an air conditioner, high-temperature, high-pressure refrigerant discharged from a compressor 1 and frozen oil for lubrication mixed with this refrigerant are passed through a four-way valve 2 to an outdoor heat exchanger. 3, where the heat is exchanged to become a high-temperature, high-pressure liquid refrigerant, and this liquid refrigerant passes through the distributor 4, is depressurized by the expansion valve 5, and is strained into the indoor heat exchanger 7 through the connecting pipe 6. The power evaporates here and passes through the connecting pipe 8 to the four-way valve 2.
A circulation cycle is formed in which the air is sucked into the compressor 1 again through the accumulator 9.

However, in such a refrigeration cycle, the pressure 1alff1
When the refrigerant was started, the refrigerant that had been mixed into the refrigerating machine oil and was in a so-called stale state started to rise to 7 ohms, causing a large amount of refrigeration ().
The refrigerating machine oil is discharged, and the discharged refrigerating machine oil circulates through the refrigeration cycle and is compressed. It takes a long time for the compressor to return to the compression range (1), and the refrigerating machine oil in the compression range (1) decreases, causing poor lubrication of the compressor and scorching of the sliding parts. , These drawbacks also occur during heating operation.

Furthermore, when performing compression (capacity control operation or low load operation), the amount of refrigerant circulated decreases and the speed of the refrigerant flowing in the piping decreases, resulting in poor compression of the refrigerant oil (return to the outlet). Therefore, as mentioned above, there is a drawback of poor lubrication of the compression margin between the studs.

This invention attempts to eliminate the above-mentioned drawbacks of the conventional ones, and includes an oil separator between the discharge side of the compression allowance and the four-way valve, and bypasses the oil separator and accumulator via a solenoid valve. By connecting the above-mentioned solenoid valve with a control device and opening the compression for a certain period of time from the time of startup, the refrigerating machine oil is returned to the Akinimulator from the bypass path, thereby preventing poor lubrication of the compressor due to a lack of refrigerating machine oil. To provide a refrigeration cycle for an air conditioner that
"It has been the target.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In FIG. 2, parts that are the same as those in FIG. 1 are given the same reference numerals, and their explanation will be omitted. Reference numeral 10 denotes an oil separator, and this oil separator 10 is provided between the discharge side of the compression allowance 1 of the refrigeration cycle and the four-way valve 2, with two parts connected thereto.

Reference numeral 11 indicates a bypass passage connecting the lower part of the oil separator 10 and the 7-cumulator 9, and reference numeral 12 indicates a solenoid valve provided in the middle of the bypass passage 11.

FIG. 3 shows the electrical circuit of the control device according to this embodiment.

In Fig. 3, CM is an electric motor for compression <1, F and M are electric rocks for blowing air to the outdoor heat exchanger 3, and F
2M is a blower electric motor for blowing air to the indoor heat exchanger 7, SWl is an operation switch, SW2 is an air conditioning/heating selector switch, and 23~' are indoor temperature thermo switches. The contacts of the thermoswitch 23W are switched between (c) and (a), and when the temperature is lower than the set value, the contacts are switched between (b) and (c). 5
2F is the coil of the contactor for the air blower (Ikuyo Electric Iso F2M), and when this coil 52F is energized and excited, its contact 52
When the contact 52f is closed, the blower motor F2M is energized and operated, and then deenergized and deenergized, the contact 52f is opened and the blower motor F2M is stopped. Further, 52C is a contactor fill for the compression substitute electric motor CM and the blower electric motors F and M. When this fill 52C is energized and excited, its contact 52c is closed, and the compression (substitute electric motor tficM and blower electric motor F , M are operated and de-energized, the contact S2c is opened, and the compression substitute electric motor TF4 CM and the blower electric motor F1M are stopped. 21C is the solenoid valve 12
When this coil 21C is energized and excited, the solenoid valve 12 is opened, and when it is de-energized, the solenoid valve 12 is opened.
is closed. 21S4 is a coil of the four-way valve 2. When this fill 21S4 is energized and excited, the heating operation is performed in which refrigerant flows as shown by the broken line arrow in FIG. The four-way valve 2 is switched so that the cooling operation (or defrost operation) is performed. TM is a timer motor, which rotates when energized and stops rotating when de-energized.

jan is the contact point of the timer, and the set time (tm+ +t
m2), the timer motor rotates once, and at this time, the contact Lm is opened for the set time tln1, and the contact L+n is closed during the next set time tm2, and this process is repeated. Y is a time-limited relay, and when energized, this time-limited relay Y operates for a certain period of time L.
After m3, the contact y is closed, and thereafter, as long as the current is energized, the contact y is open. And coil 5 of the contactor
2C1 electromagnetic 012 coil 21C, timer motor TM
, the time-limited relay Y is connected in parallel to the contact point (c) of the indoor temperature thermoswitch 23W.

26S is a contact point of a thermos node attached to the suction pipe, which closes when the temperature falls below a certain set value and opens when the temperature rises above the set value. 26D1 is a contact point of the defrost start thermostat, which closes when the temperature falls below a set value and opens when the temperature rises above the set value.

61) 2 is a contact point of the defrost end thermostat,
It closes when the temperature falls below the set value and opens when the temperature rises above the set value. Note that the setting value of the defrosting start thermostat is lower than the setting value of the defrosting end thermostat (7f1). ×2 is the fill of the auxiliary relay, and the thermostat 26r), 26
Connected in series with D2, when energized and excited, its contact 2χ
a closes, contacts 2χ13゜2χc, 2χd, 2χe open, and when deenergized, contact 2χa opens and contacts 2χ1),
2χc, 2χd.

2χe closes. ×3 is the coil of the auxiliary relay,
It is connected in series with the contact 26S of the thermostat, and when it is energized and energized, its contact 3χa closes, and when it is deenergized and deenergized, its contact 3χa is opened. ×1 is the coil of the auxiliary relay, which is connected in series with the thermostat contact 261, )1.26D2 and in parallel with the auxiliary 1st filter ×2, and when energized 1j
Is that what happens when you get l+magnetized? Contact 1χa
is closed, and when deenergized and deenergized, contact 1χa opens. Also,
The fill 21 of the solenoid valve 12 is connected to the timer contact tn+, the time limit relay Y contact y, and the auxiliary relays X2 and x3 contact 2.
χa and 3χa are connected in parallel.

When the indoor temperature is higher than the setting value of the thermo switch 23w during cooling, when the operation switch S~'5 is turned on, the coil 52F of the contactor is energized and the contact 52f is closed, and the blower of the indoor heat exchanger is turned on. electric motor (number F2h=i
is started, the air conditioning/heating selector switch SW2 is set to the cooling side (d), and the contacts (a) and (c) of the thermo switch 231tl are activated.
is connected, the fill 52C of the contactor is excited and the contact 52c is closed, and the compressor electric motor CM starts to drive and the compressor 1 is started.

Further, since the time-limited relay Y is also energized, the contact y is closed, the coil 2IC of the solenoid valve is energized, the solenoid valve 12 is opened;), and the bypass path 11 is opened.

Furthermore, after the set time tm3 has elapsed, the time-limited relay Y is demagnetized and the contact y is opened, the coil 21C of the solenoid valve is demagnetized, the solenoid valve 12 becomes idle, and the bypass path 11 is closed. Note that this also applies to startup during heating. The timer motor TM is energized and continues to rotate for the set time t1.
When n+ has elapsed, contact ttn closes (toner 1), solenoid valve ty>coil 21 (J'rjh is magnetized and solenoid valve 12 is opened, and after set time t+n2, contact L111 is opened and coil 2IC is demagnetized. Solenoid valve 12 closes,
Thereafter, the above-described operation is repeated. Note that this also applies during heating.

During heating, when the indoor temperature is lower than the set value of the thermo switch 23', V, when the operation switch S'vV is turned on, the coil 52F of the contactor is energized, the contact 52[ is closed, and the indoor heat exchanger is closed. The blower electric Iso r-'2M is started, the air conditioning/heating selector switch SW2 is set to the heating side (E), the coil 21S of the four-way valve 2 is energized, and the heating operation is started, and the contacts (B) and (C) of the thermo switch 23tlI are activated.
is connected, the coil 52C of the contactor is energized, the contact 52c becomes idle, and the j-j transmission r1 is activated.

Since the time-limiting relay Y is also energized, the contact y becomes idle and the coil 21C of the solenoid valve is energized, so that the solenoid valve 12 is opened and the bypass path 11 is formed.

Furthermore, after the set time tτ03, the time-limited relay)' is demagnetized, the contact y is opened, the coil 2IC is demagnetized, the solenoid valve 12 is idle, and the bypass path 11 is closed.

The timer motor TM is energized and continues to rotate, and the filter 21C is energized after the set time t+n1 has elapsed, and is demagnetized after the set time 1+n2 has elapsed, and the solenoid valve 12 is opened and closed, as in the case of cooling mentioned above. Repeat the action.

In addition, when the heating temperature is low (the temperature of the thermostat set aside for the two suction pipes is below the set value), the contact 26
S is closed, the auxiliary relay coil x 3 is energized, the contact 3χa is closed, the solenoid valve coil 21C is energized, the solenoid valve 12 is opened, and the reno path 11 is opened.

Furthermore, defrosting is performed when the set temperature falls below the set value of the higher defrost end thermo stand, and that contact 26D2 closes, and then when it falls below the set value of the defrost start thermo stand. The contact 26D1 is closed,
Since the coil X2 of the auxiliary relay is excited and the contact 2χC is opened, the coil 21S of the four-way valve 2 is demagnetized and defrosting begins.

At the same time, contact 2χd of coil X2 of the auxiliary relay.

2χe is opened, and the indoor heat exchanger 7 is stopped, and the contact 2χa is opened, and the electromagnetic valve fill 2 is closed.
The IC 16j is magnetized, the solenoid valve 12 is opened, and the bypass passage 11 is opened. Further, the coil x1 of the auxiliary relay is energized to close the contact 1χa, and is connected in parallel to the contact 26D1 of the defrosting start thermostat. When defrosting starts, the temperature immediately rises by 1 from the set value of the defrosting start thermo stand, and its contact 2 becomes open.
Defrost end thermostat contact 26D7. Contact point 1χa,
Auxiliary relay coil X2. A circuit of XI is formed. When the temperature rises above the defrost thermostat set value,
Its contact 26+)2 becomes open, and the auxiliary relay coil
2゜Xl? The porcelain is polished and the frosting process is completed.

Next, the operation of the refrigeration cycle shown in FIG. 2 will be explained. In Fig. 2, solid arrows indicate the flow of refrigerant during cooling and defrosting operations, dashed arrows indicate the flow of refrigerant during heating, and dash-dotted lines indicate the flow of refrigerant and refrigeration in the bypass path (in private lodging).

During cooling operation, high-temperature, high-pressure refrigerant gas discharged from the compressor 1 and refrigerating machine oil enter the oil separator 10 from below, and the refrigerating machine oil is separated from the refrigerant gas and accumulates at the bottom of the oil separator 10. There is. The refrigerant gas separated from the refrigeration oil is transferred to oil separator 1.
0, passes through the four-way valve 2, reaches the outdoor heat exchanger 3, where it exchanges heat and becomes a high-temperature, high-pressure refrigerant liquid, passes through the distributor 4, is depressurized by the expansion valve 5, and is transferred to the connecting pipe 6.
It evaporates in the indoor heat exchanger 7 and then connects to the connecting pipe 8.
, the four-way valve 2, and the accumulator 9.

During this operation, the solenoid valve 12 located in the middle of the bypass path 11
If the oil separator 10 is closed, the solenoid valve 12 is opened by a signal, and the refrigerating machine oil accumulated at the bottom of the oil separator 10 passes through the bypass path 11 and closes the solenoid valve 12. The refrigerant gas is returned to the accumulator 9 through the compressor, and together with the low-temperature, low-pressure refrigerant gas that has returned from the indoor heat exchanger 7, it is compressed (returns to 1), and the refrigerating machine oil circulation circuit is significantly shortened. is almost the same during heating operation.

Therefore, if the distance between the indoor unit and the outdoor unit of the air conditioner is far apart, that is, the connection piping 6
, 8. Even if the refrigeration oil circulation circuit is short, passing through the bypass path 11, compression (; AC 1 refrigeration (no shortage of private lodging) will occur. Also, in the case of pressure 1 tliilt history 1 or capacity control type, During operation, the amount of circulating refrigerant discharged from the compressor decreases significantly, and even when the speed at which the refrigerant moves in the piping decreases, refrigeration (in private lodging houses, the distance of the circulation circuit is short) Therefore, there will be no shortage of refrigerated (minpaku) returns.

When the compressor 1 is started, the solenoid valve 12 is kept open for a certain period of time tm3 by the time-limited relay Y, so that when the compressor 1 is stopped, the refrigerant mixed in the refrigerating machine oil is removed. Even if a large amount of refrigerating machine oil or compressor 1 is discharged compared to normal continuous operation IL11 due to the 7 ohm start-up, the oil separator 10 separates the refrigerant from the refrigerating machine oil or refrigerant. It returns to the accumulator 9 via the bypass path 11 via the open electromagnetic valve 12 without circulating through the circuit, and returns to the compressor 1 together with the low-pressure gas, where it is compressed (de-refrigerated and refrigerated). It's hard to make up for it in a short time.

Furthermore, when the heating operation changes to the defrosting operation, the auxiliary relay coil x 2 is energized, the contact 2χa is closed, the solenoid valve coil 21C is energized, the solenoid valve 12 is opened, and at the same time, the four-way valve 2 is switched. . Therefore, the high-temperature, high-pressure refrigerant gas compressed by the compressor 1 passes through the oil separator 10, the four-way valve 2, and the outdoor heat exchanger 3, where it is defrosted and then disposed of. 4, the pressure is reduced by the expansion valve 5, the connection pipe 6, the indoor heat exchanger 7, the connection pipe 8, and the four-way valve 2 are returned to the accumulator 5].

At the same time, some of the high-temperature, high-pressure refrigerant scum that came out of the compressor 1
From the bottom of oil separator 1 () via 7X Ipass path 11,
It passes through the solenoid valve 2 and is returned to the aqueous L and rake (J).

In the accumulator 9, the low-pressure refrigerant gas is mixed with the low-temperature, low-pressure refrigerant gas that has passed through the indoor heat exchanger 7, which functions as an evaporator, and the high-temperature, high-pressure refrigerant gas that has passed through the bypass path 11. The pressure increases and returns to compression. As a result, it is possible to create a state in which the specific volume of the refrigerant scum is small and the circulation rate is large, thus making it possible to dissolve and remove "1-1" attached to the outdoor heat exchanger 3 in a short time. can.

When the temperature is low for heating, there is a risk that the heat will quickly reach the outdoor heat exchanger 3, so if the temperature falls below the set value of the thermostat attached to the suction pipe, its contact 26S will close, and the coil of the auxiliary relay 3 is energized and its contact 3
χa is closed, the solenoid valve coil 21C is energized, the solenoid valve 12 is opened, and a part of the high-temperature, high-pressure refrigerant gas discharged from sentence 1 is transferred to the accumulator via the oil separator 10 and the bypass path 11. The air is bypassed and returned, thereby increasing the heating capacity at low temperatures.

When using a variable capacity compression valve 1, double solenoid valve 122 for defrosting and heating at low temperatures is used.
In the state of ``open ys (y>
It is more effective in increasing heating capacity.

During cooling or heating operation, compression (for a certain period of time t after startup)
n)l continuous operation, and then the timer motor TM
The contact t111 becomes idle and the timer motor TM continues to rotate, so that the coil 2IC is energized for a set time Lm3 at intervals of tm2 and the solenoid valve 12 is opened, so that oil is stored in the oil separator 10. Frozen (homestay)
From the oil separator 1 ( ) via the bypass path 11 to the solenoid valve 12
It is returned to the accumulator 9 via the evaporator, and is compressed together with the low-temperature, low-pressure refrigerant power that has returned from the heat exchanger that serves as the evaporator. , the shortage will not occur.

Furthermore, since the refrigeration cycle of this embodiment is configured as a double series, the refrigerant accumulated in the connecting pipe 8 when the air conditioning system is stopped returns to the discharge side of the pressure *1i (11) by its own weight. Even if the oil is stored in the oil separator 1, it can be compressed and prevented from entering the discharge port. .

In addition, in the above embodiment, the compression stage is located outside the room (although the present invention is also applicable to a remote type air conditioner where the compression stage is located outside the room). Although an expansion valve is used as the throttling device in the embodiment described above, the present invention can also use a throttling device such as a cavillary tube, an electric expansion valve, or an orifice.
The throttle device can be placed anywhere between the indoor heat exchanger and the outdoor heat exchanger.

As explained above-1-, according to the present invention, an oil separator is provided between the discharge side of the compression chamber and the four-way valve, and the oil separator and the accumulation rake are connected via the solenoid valve by a bypass path. By opening the above solenoid valve, the refrigerating machine oil and high-temperature, high-pressure refrigerant gas are returned to the accumulator via the bypass path, so the installation distance between the indoor and outdoor units, that is, the connecting piping between these can be lengthened. It is easy to do this, and even if the refrigerant discharge amount is significantly reduced when variable capacity compression (branches are used), refrigeration (oil can be easily and sufficiently returned to compression). In particular, the control device is equipped with a means of opening the solenoid valve when the compressor is started and closing it after a certain period of time. Even if a large amount of refrigeration oil is discharged from the compression stage compared to during operation, the refrigerating machine oil can be easily returned to the compression stage in a short time, which improves the comfort of the heat pump.
The effect is that a highly reliable and highly accurate refrigeration cycle can be provided at low cost with a simple configuration.

[Brief explanation of drawings]

Fig. 1 is a structural explanatory diagram showing a refrigeration cycle of a conventional air conditioner, Fig. 2 is a structural explanatory diagram showing a refrigeration cycle according to a first embodiment of the present invention, and Fig. 3 is a structural explanatory diagram showing a refrigeration cycle according to an embodiment of the present invention. FIG. 3 is an electrical circuit diagram of the control device. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Four-way valve, 3... Outdoor heat exchanger, 1... Distributor, 5... Expansion valve, 6. S... Connection piping, 7... Outdoor heat exchanger, 5
"...Accumulator, 10...Oil separator, 11
... Bypass path, 12... Solenoid valve. Cki・1...Electric boat for compression rock 1\i, p: hi...Electric boat for blowing outdoor and indoor heat exchangers for rocky shore S Wl... Operation switch S~',...・Air conditioning/heating selector switch 23~'... Indoor temperature switch 52C, 52F
... Contactor coil 21C ... Solenoid valve coil 21S, ... Four-way valve coil T M ... Time motor Y ... Time limit relay 26D, 26D, ... Start defrosting, Defrost end thermostat contact 268...Thermostat contact XI, X2. X3... Auxiliary relay fill. In addition, the same symbols in the figures indicate the same or equivalent parts. 1982-'
13 tv 36 No. 2, Akira Zugo's name Air conditioner refrigeration cycle: 3 Name of person making the supplement Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 1, Agent (1) Invention of the specification Contents of the m16° correction in the detailed explanation (1) The word "thermostat" on page 7, line 6 of the specification is corrected to "thermostat j." (2) The word "thermostat" on page 7, line 20 of the same specification is corrected as "coil, 2. 7" should be corrected to "Coil 2/C". 272

Claims (1)

[Claims] In an air conditioner with a refrigeration cycle in which a pressure 1+i iso, a four-way valve, an outdoor heat exchanger, a throttling device, an indoor heat exchanger, and an accumulator are connected in a ring, it is installed between the discharge side of the compressor and the four-way valve. an oil separator, a bypass path connecting the oil separator and the accumulator via a solenoid valve, and a control device having means for opening the solenoid valve and closing it after a certain period of time when the pressure A11i is activated. (lf
The air conditioning system (the refrigeration cycle) is characterized by a wide range of features.