JPS6122749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in air conditioners.

The first objective of the present invention is to reduce the load of air conditioners or the installation of indoor units even when distribution of two-phase refrigerant during cooling is difficult or even when this distribution is ideally performed. This enables control appropriate to the load during cooling, which cannot be operated smoothly due to differences in refrigerant pressure loss due to differences in position.

The second purpose is to simplify and simplify the refrigerant system and reduce costs by using a capillary to control the amount of refrigerant being circulated and condensation easily during heating, and at the same time also using a return capillary.

To explain one example of a conventional air conditioner,
First, regarding the cooling operation, as shown in Fig. 1, the compressor 1
The high-pressure gas refrigerant discharged from the 4-way valve 15 (broken line in the figure) enters the outdoor coil 1 which operates as a condenser.
6, it is cooled by an outdoor fan 14, where it is condensed and becomes a liquid refrigerant, passing through a check valve 13 to the receiver 1.
0, leaving the non-condensable gas refrigerant or surplus refrigerant, and passing through the liquid side solenoid valves 4A, 4B, 4C, and from the liquid side operation valves 7A, 7B, 7c to the liquid piping 17A,
Each indoor unit A, B, C via 17B, 17C
is connected to. Next, the high pressure liquid refrigerant flowing into each indoor unit passes through the liquid side operation valves 24A, 24B, 24.
Each indoor coil 23A, which expands adiabatically through expansion valves 20A, 20B, and 20C through C, and works as an evaporator.
Indoor fans 22A, 22B, 2 with 23B and 23C
It is heated by 2C and evaporates to become a gas refrigerant, absorbing the latent heat of vaporization from the indoor air, thereby cooling the room. Next, the gas side operation valve 26A,
Gas piping 18A, 18B, 1 from 26B, 26C
Connected to the outdoor unit via 8C. The low pressure gas refrigerant returned to the outdoor unit via the gas side operating valves 8A, 8B, 8C is passed through the gas side solenoid valves 5A, 5B, 5C.
It passes through the four-way valve 15, the accumulator 11, and is sucked into the compressor 1 to form a cycle.

The liquid side solenoid valves 4A, 4B, and 4C are opened and closed according to the operation of the indoor units A, B, and C, and are opened and closed simultaneously with the gas side solenoid valves 5A, 5B, and 5C. Further, the liquid side operation valves 7A, 7B, and 7C do not necessarily need to be opened when the gas side solenoid valves 5A, 5B, and 5C have built-in check valves.

Regarding heating, the basic refrigeration cycle is the same as that for cooling, but the outdoor coil 16 acts as an evaporator, and each indoor coil 23A, 23B, 2
The main differences are that 3C functions as a condenser and that the four-way valve 15 is connected to the solid line side in the figure.

Then, the refrigerant discharged from the compressor 1 passes through the four-way valve 1.
5 to gas side solenoid valves 5A, 5B, 5C and gas side operation valves 8A, 8B, 8C to gas piping 18A,
It is connected to the gas side operation valves 26A, 26B, 26C of the indoor units A, B, C through 18B, 18C, and is cooled by the indoor fans 22A, 22B, 22C through the indoor coils 23A, 23B, 23C, and is condensed and liquefied. Here, the latent heat of condensation is released to the indoor air, so the indoor room is heated. Next, through the check valves 21A, 21B, 21C, the liquid side operation valves 24A, 24B, 24C, and the liquid pipes 17A, 17.
B, 17C, outdoor unit liquid side operation valve 7A, 7
B, 7C, through the liquid side solenoid valves 4A, 4B, 4C, passes through the receiver 10, expands adiabatically by the expansion valve 12, enters the outdoor coil 16, is heated by the outdoor fan 14, evaporates, and becomes a low-pressure gas refrigerant.Four-way valve 15 to the compressor 1 via the accumulator 11
is inhaled to form a cycle.

In order to keep the degree of superheat at the outlet of each indoor coil constant during cooling operation, expansion valves 20A, 20B, 2 are provided.
0C is used, and in order to adjust the degree of superheating, the temperature sensing cylinders 28A, 28B, 28 of the expansion valve detect the temperature of the outlet pipes of the indoor coils 23A, 23B, 23C.
C to indoor coil outlet piping 27A, 27B, 27C
Attach to. This temperature-sensitive cylinder has expansion valves 20A, 20
B, 20C and capillary tube 29A, 29
B, connected at 29C.

Note that when operating only indoor unit A during heating operation, for example, gas side solenoid valves 5B, 5C and liquid side solenoid valves 4B, 4C are closed, but indoor units B and C close gas side solenoid valves 5B, 5C, If the refrigerant leaks from the liquid-side solenoid valves 4B and 4C and condenses, this will gradually progress, resulting in a refrigerant shortage in the refrigerant cycle. The reason for this is that the indoor coil temperature of the indoor unit is about 20°C, whereas the condensation temperature of high-pressure refrigerant is about 40°C, so there is a temperature difference and the refrigerant condenses inside the indoor unit.

Furthermore, the above description has been made regarding the case where only indoor unit A is operated, but for example, when operating indoor unit A and switching to indoor unit B, a considerable amount of liquid refrigerant is stored in unit A during operation, and this state If unit B continues to operate as it is, unit B will operate with a lack of refrigerant, resulting in problems such as insufficient capacity and damage to the compressor. To prevent this, in order to connect the indoor unit that is not in operation to the piping equipment after the low pressure side expansion means of the refrigeration cycle, the liquid side operating valves 7A, 7B, 7C and the liquid side solenoid valve 4A,
Take a bypass circuit from between 4B and 4C and connect the check valves 9A, 9B, 9C and the refrigerant return capillary 6A,
6B and 6C are connected in series, respectively, and connected to the low pressure piping section between the expansion valve 12 and the outdoor coil 16.

At this time, in the case of the indoor unit in operation, for example, unit A, the pressure due to the refrigerant return capillary 6A is higher than the pressure drop in normal operation from the liquid side operation valve 7A through the liquid side solenoid valve 4A to the receiver 10 and the expansion valve 12. Since the drop is selected to be large, the amount of refrigerant flowing from the liquid side operation valve 7A to the refrigerant return capillary 6A is very small, and the refrigerant return capillaries 6A and 6B are connected to the rest units B and C.
of refrigerant will be recovered. The reason is that the expansion valve 12 changes its opening degree (resistance) depending on the load, and the opening degree (resistance) cannot be arbitrarily selected. On the other hand, the refrigerant return capillary can be arbitrarily selected to provide greater resistance than the degree of opening of the expansion valve in normal operation.

In this case, the indoor unit has expansion valves 20A and 20.
B, 20C, noise (refrigerant flow noise) and vibration (accompanied by refrigerant expansion) occur during cooling, which becomes a big problem especially as the overall noise level of indoor units has been decreasing recently. In addition, check valves 13, 21A, 21 are used on the bypass side of the expansion valves 20A, 20B, 20C for cooling and the expansion valve 12 for heating.
B and 21C were required, and the expansion valve and check valve were an obstacle to making it into a small indoor unit.

The present invention was developed as a result of intensive research to improve these drawbacks, and as a result, the expansion valves and check valves were removed from the indoor units A, B, and C, and the expansion valves were installed in the outdoor units.

That is, the present invention provides a heat pump air conditioner in which one outdoor unit equipped with a compressor and an outdoor heat exchanger is connected to a plurality of indoor units equipped with indoor heat exchangers. The same number of expansion units as the above-mentioned indoor units are constructed by connecting in parallel a cooling expansion mechanism equipped with a cooling expansion valve and a shutoff valve, and a heating expansion mechanism equipped with a heating capillary and a check valve, respectively. It is characterized by being connected to the refrigerant pipe in parallel with the refrigerant pipe.

Examples of the present invention will be shown and explained in detail.

Example 1 Regarding cooling operation As shown in Fig. 2, the compressor 1
The high pressure gas refrigerant discharged from
4, the refrigerant becomes a liquid refrigerant, enters the receiver 10, passes through the check valve 19, and enters the liquid side solenoid valve 4A,
4B, 4C, expands adiabatically with expansion valves 2A, 2B, 2C, connects to indoor units A, B, C via liquid side operation valves 7A, 7B, 7C, liquid side pipes 17A, 17B, 17C, and connects to indoor units A, B, C. Operation valves 24A, 24B,
Indoor coils 23A, 23B, 23 through 24C
At C, it is heated by indoor fans 22A, 22B, and 22C and evaporates, becoming a gas refrigerant and gas side operation valve 26.
Gas side piping 18A via A, 26B, 26C,
It is connected to the outdoor unit via 18B and 18C, and the gas side solenoid valve 5 is connected to the gas side operating valves 8A, 8B, and 8C.
After passing through A, 5B, and 5C, they join together and are sucked into the compressor 1 through the four-way valve 15 and the accumulator 11.

The temperature sensing tubes 28A, 28B, and 28C of the expansion valves are attached to the piping between the gas side operating valves 8A, 8B, and 8C and the gas side solenoid valves 5A, 5B, and 5C in the outdoor unit.

Note that in the above, the check valve 19 does not necessarily need to be installed, and the solenoid valve 4 may be any valve that blocks the flow of refrigerant. Further, the expansion valve 2 and the electromagnetic valve 4 may be installed first, and the expansion valve 2 may be a throttle capillary tube as long as it expands the refrigerant.

In this manner, depending on the operating status of indoor units A, B, and C, for example, when only indoor unit A is operated, the liquid side solenoid valve 4A and the gas side solenoid valve 5A are energized, and the refrigerant flows only to indoor unit A. In the case of two-room operation, for example, in the case of indoor units A and B, the liquid side solenoid valves 4A and 4B and the gas side solenoid valves 5A and 5B are opened.

Further, in the present invention, the compressor 1 is preferably one whose capacity is variable according to the load condition of the air conditioner, for example.
We have described a compressor in which the number of poles of the motor can be changed, such as operating the compressor motor with four poles when operating only one indoor unit, and operating with two poles when operating two or three indoor units simultaneously. A capacity control method using a refrigerant bypass method may also be used. It can also be applied when using a compressor whose capacity cannot be changed.

Next, regarding heating operation, contrary to the case of cooling, the four-way valve 15 becomes the circuit shown by the solid line in the diagram, and the high-pressure gas refrigerant discharged from the compressor 1 passes through the gas-side solenoid valves 5A, 5B, and 5C by the four-way valve 15. Gas piping 18A, via gas side operation valves 8A, 8B, 8C.
It is connected to indoor units A, B, C through gas side operation valves 26A, 26B, 26C through indoor coils 23A, 23B, 23C, and is cooled by indoor fans 22A, 22B, 22C and condensed into liquid refrigerant. The liquid side operation valves 24A, 24B,
Liquid side piping 17A, 17B, 17C via 24C
Connected to the outdoor unit via the liquid side operation valve 7A,
After passing through 7B, 7C, liquid side solenoid valves 4A, 4B, 4
Since C is de-energized during heating, it flows to the heating capillary 3A, 3B, 3C side, and the check valves 9A, 9
B and 9C, enters the outdoor unit 16 from the receiver 10, is heated and evaporated by the outdoor fan 14, and is sucked into the compressor 1 from the four-way valve 15 via the accumulator 11.

Note that in the above, the check valve 9 allows the refrigerant to flow only in the direction of the outdoor coil. Further, the order of the check valve 9 and the heating capillary tube 3 may be reversed.

Next, when one indoor unit, for example unit A, is operated, only the gas side solenoid valve 5A is opened and the solenoid valves 5B and 5C are closed. The refrigerant discharged from the four-way valve 15 passes only through the gas side solenoid valve 5A, and then passes through the gas side operating valve 8A, gas piping 18A, gas side operating valve 26A, indoor coil 23A, and liquid side operating valve 2.
4A, liquid piping 17A, liquid side operation valve 7A, heating capillary 3A, check valve 9A, receiver 10, outdoor coil 16, four-way valve 15, and accumulator 11.

On the other hand, solenoid valves 5B and 5 are installed in indoor units B and C.
If refrigerant remains in indoor units B and C due to leakage of C or switching of indoor units, the heating capillaries 3B and 3C function in the same way as the return capillaries 6B and 6C in FIG. By being connected to the low pressure circuit of the refrigerant cycle between the check valve 19 and the receiver 10 via the valves 9B and 9C, it is returned to the refrigeration cycle in operation.

Since the present invention is based on such a mechanism, it has the following effects.

(1) The expansion valve can be moved from the indoor unit to the outdoor unit as a refrigerant throttling mechanism during cooling operation, making it possible to eliminate noise caused by adiabatic expansion of the refrigerant. Also, noise is generated on the outdoor unit side, but since the outdoor unit has sources such as compressors and outdoor fans that generate much higher noise levels than the indoor unit, it is mixed and absorbed by these sounds, and almost no noise is heard outside. There is no inconvenience because I don't hear anything.

(2) The product price is reduced by changing the expansion valve to a capillary during heating operation, and the capillary acts as a heating capillary (throttling mechanism) for the operating unit, and there is a rest unit that is not operating. In this case, the refrigeration cycle can be simplified because it can also be used as a return capillary to prevent refrigerant from accumulating in the rest unit.

Embodiment 2 As shown in FIG. 3, the amount of refrigerant throttling during heating operation is finely controlled in accordance with the number of operating indoor units.

That is, the heating capillary (return capillary for the rest unit) is connected to the heating main capillary 3A,
3B, 3C and heating auxiliary capillary 3AB, 3
It is composed of both BC and 3AC,
This heating main capillary 3A, 3B, 3C is the second
Compared to the capillaries 3A, 3B, and 3C shown in the figure, the amount of restriction (resistance) is larger and the flow rate of refrigerant passing therethrough is reduced.

Therefore, in the case of indoor unit A only, the operation only during heating is performed by the check valve 9 via the liquid side operation valve 7.
The high-pressure liquid refrigerant that has passed through it mainly enters the main heating capillary 3A depending on the amount of restriction of the capillary, but at the same time enters the main heating capillaries 3B and 3C via the auxiliary heating capillaries 3AB and 3AC. Also, at this time, the pressure between the check valve 9B and the heating main capillary 3B becomes almost low pressure, so the liquid refrigerant remaining in the indoor unit B that is inactive returns to the cycle through the check valve 9B. be. The same applies to indoor unit C.

In this way, the main heating capillary 3A, the auxiliary heating capillary 3AB, and the main heating capillary 3B are connected in series, and the auxiliary heating capillary 3
This is the sum of the AC and heating main capillary 3C connected in series.

Note that the pressure is almost the same before and after the heating auxiliary capillary, and almost no refrigerant flows into the heating auxiliary capillary 3BC.

The same applies to the operation of only indoor unit B and indoor unit C.

Next, referring to the heating operation of two indoor units A and B, the high-pressure liquid refrigerant that passes through the liquid-side solenoid valves 7A and 7B and the check valves 9A and 9B mainly flows into the heating main capillaries 3A and 3B. However, a portion bypasses and passes through the heating main capillary 3C. That is, the liquid refrigerant from the indoor unit A passes through the auxiliary heating capillary 3AC, and the liquid refrigerant from the indoor unit B passes through the auxiliary heating capillary 3BC and enters the main heating capillary 3C. At this time, almost no refrigerant passes through the heating auxiliary capillary 3AB.

Also, the refrigerant remaining in the indoor unit C that is inactive is frozen through the check valve 9C and the heating main capillary 3C for the same reason as when one unit is in operation (pressure difference before and after the check valve 9C). Return during cycle.
The same applies to indoor units B, C, and indoor unit AC.

Next, a case where three indoor units are operated will be explained. That is, in Example 1, the heating capillary is selected to have an appropriate size when one or two indoor units are operating, so when three indoor units are operating, the refrigerant is in the heating capillary 3A. , 3B, and 3C at the same time, the amount of throttling is insufficient and the liquid tends to back up a little.

However, the heating main capillary 3 shown in FIG.
A, 3B, 3C are heating capillary 3 in Figure 2.
Since the amount of throttling is larger than that of A, 3B, and 3C, the amount of throttling is selected so that even if refrigerant flows into the three capillaries at the same time, there will be no liquid backlash, thereby preventing damage to the compressor.

In addition, in Example 1, the capillary 3 of the three
It is possible to select the best option when flowing refrigerant to A, 3B, and 3C, but in this case, conversely, when one or two indoor units are operating, the amount of refrigerant circulating decreases, causing overheating and compression. This may cause damage to the machine.

In this embodiment, fine control can be performed depending on the load.

Embodiment 3 As shown in FIG. 4, the cooling operation cycle is exactly the same as that in FIG. They have different mechanisms.

In the case of heating operation with one indoor unit A, most of the refrigerant that has passed through the liquid side operation valve 7A passes through the heating main capillary 3A, then the check valve 9A, and some of the refrigerant passes through the heating auxiliary capillary 3AB, 2AC and the heating main capillary. It passes through check valves 9B and 9C via check valves 9B and 3C, and then joins with the refrigerant through the check valve 9A and enters the receiver 10. The refrigerant from indoor units B and C is supplied to the heating main capillary 3 as in the second embodiment.
It is returned during the cycle via B and 3C.

In the case of heating operation of two indoor units A and B, the check valve 9 is connected to the heating main capillary 3A, 3B.
Passing through A and 9B and heating auxiliary capillary 3
The refrigerant is divided into those that pass through the heating main capillary 3C and the check valve 9C from AC and 3BC, and the refrigerant that returns from the idle indoor unit C is returned during the cycle via the heating main capillary 3C.

For operation of three indoor units, check valves 9A, 9 are connected from heating main capillary 3A, 3B, 3C.
B and 9C, the signals merge and enter the receiver 10.

Embodiment 4 As shown in FIG. 5, the heating expansion mechanism shown in FIG. Capillary 3A, 3
B and 3C are arranged in this order.

In the case of heating operation with one indoor unit A, most of the liquid refrigerant that has passed through the liquid side operation valve 7A passes through the check valve 9A and enters the heating main capillary 3A, and some of it is reversed from the heating auxiliary capillary 3AB, 3AC. Heating auxiliary capillary 3 passes through stop valves 9B and 9C.
B, 3C, after passing through, merges with the main stream and receiver 10
Return to Regarding the return refrigerant from the idle indoor units B and C, check valves 9B and 9 are connected in the same manner as in the embodiment.
C, it is connected to the low pressure side via the heating main capillaries 3B and 3C, so it is returned during the cycle.

The same applies to the operation of two or three units.

As detailed above, according to the present invention, the refrigerant control is provided outside the room, simplifying the refrigeration cycle, significantly reducing noise, and commercializing the product at a low price, making it extremely useful as an air conditioner. It is.

[Brief explanation of the drawing]

FIG. 1 is a mechanical explanatory diagram showing an example of a conventional air conditioner, and FIGS. 2 to 4 are an illustration of an example of the air conditioner of the present invention.
FIG. 5 is a diagram illustrating a modification of the heating expansion mechanism shown in FIG. 4. A, B, C... Indoor unit, 1... Compressor,
2A, 2B, 2C...Expansion valve, 3A, 3B, 3C
... Heating capillary, 4A, 4B, 4C ... Liquid side solenoid valve, 5A, 5B, 5C ... Gas side solenoid valve, 6
A, 6B, 6C...Refrigerant return capillary, 7
A, 7B, 7C...Liquid side operation valve, 8A, 8B, 8
C...Gas side operation valve, 9A, 9B, 9C...Check valve, 10...Receiver, 15...Four-way valve, 18
A, 18B, 18C...Gas piping, 20A, 20
B, 20C...Expansion valve, 21A, 21B, 21C
... Check valve, 22A, 22B, 22C ... Fan, 23A, 23B, 23C ... Indoor coil, 2
4A, 24B, 24C...liquid side operation valve, 26A,
26B, 26C...Gas side operation valve, 27A, 27
B, 27C...Piping, 28A, 28B, 28C...
...Temperature tube, 29A, 29B, 29C... Capillary tube.

Claims (1)

[Claims] 1. In a heat pump air conditioner that connects one outdoor unit equipped with a compressor and an outdoor heat exchanger to multiple indoor units equipped with indoor heat exchangers, the outdoor unit is equipped with a cooling expansion valve. The same number of expansion units as the above-mentioned indoor units are arranged in parallel, in which a cooling expansion mechanism each having a shutoff valve and a heating expansion mechanism each having a heating capillary and a check valve are connected in parallel. An air conditioner characterized by being connected to refrigerant piping.