JPH07310962A - Heat pump multizone type air conditioner - Google Patents

Abstract

PURPOSE:To eliminate the excess capacity, the generation of a flowing sound due to the excess flow of cooling by providing a throttle mechanism for heating in which a throttle and a check valve are connected in series with one another in parallel with an electronic expansion vale, and fully closing the valve except at the time of heating or cooling the indoor air. CONSTITUTION:Since electronic expansion valves 16a, 16b are fully closed except at the time of heating or cooling the indoor air, the valves 16a, 16b in indoor units 2a, 2b are fully closed at the time of cooling and heating in the units 2a, 2b which do not need the cooling/heating of the indoor air at the time of stopping via a thermostat, blowing or stopping, and the flow of refrigerant passing therethrough is interrupted. At the time of heating, the flow of a fine predetermined rate of the refrigerant is obtained through throttle mechanisms 19a, 19b for heating in which throttles (capillary tubes) 17a, 17b and check valves 18a, 18b arranged in parallel with the valves 16a, 16b are located in series. Thus, the excess capacity, the generation of a flowing sound due to the excess flow of the refrigerant do not occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type multi-type air conditioner.

[0002]

2. Description of the Related Art Conventionally, for example, as shown in FIG. 2, a multi-type air conditioner in which one outdoor unit 1 and a plurality (two in the figure) of indoor units 2a and 2b are connected by a refrigerant pipe. There is an opportunity.

The outdoor unit 1 is provided with a compressor 3, a four-way switching valve 4, an outdoor heat exchanger 5, a fan 6, a motor 7, an accumulator 8 and the like, and an expansion valve 10 and a check valve 11 are provided in a liquid pipe 9. It is installed in parallel.

The indoor units 2a and 2b include indoor heat exchangers 12a and 12b, fans 13a and 13b, and a motor 14, respectively.
The liquid pipes 15a, 15b are provided with electronic expansion valves 16a, 16b.

During the cooling operation, the gas refrigerant discharged from the compressor 3 enters the outdoor heat exchanger 5 via the four-way switching valve 4 as shown by the solid arrow, and is introduced by the fan 6 driven by the motor 7 there. The heat is radiated to the outside air to be condensed and liquefied. The liquid refrigerant enters the indoor units 2a and 2b via the check valve 11. And the electronic expansion valve 16
After being adiabatically expanded by being squeezed by a and 16b, it enters the indoor heat exchangers 12a and 12b, where the motor 14
The indoor air introduced by the fans 13a and 13b driven by a and 14b is evaporated and vaporized by cooling the indoor air. This gas refrigerant returns to the outdoor unit 1 and is sucked into the compressor 3 via the four-way switching valve 4 and the accumulator 8.

During the heating operation, the four-way switching valve 4 is switched in the reverse manner to the above, and the gas refrigerant discharged from the compressor 3 is, as shown by the broken line arrow, the four-way switching valve 4, the indoor units 2a, 2
indoor heat exchangers 12a and 12b in b, electronic expansion valve 16
a, 16b, the expansion valve 10 in the outdoor unit 1, the outdoor heat exchanger 5, the four-way switching valve 4, and the accumulator 8 are returned in this order to the compressor 3.

By operating a controller (not shown) connected to the indoor units 2a and 2b, individual operation / stop, operation mode switching (cooling, heating, ventilation, etc.), room temperature setting, etc. can be performed and set. It is automatically operated / stopped so that it is maintained at room temperature (hereinafter, "thermo operation /
"Stop").

When the thermostat is stopped, the air is blown and stopped (the other indoor units are operated), for example, the indoor unit 2a is in the thermostop or the blow operation is stopped and the indoor unit 2b is in operation. The electronic expansion valve 16a in the indoor unit 2a is fully closed, and the inflow of the refrigerant into the indoor heat exchanger 12a is shut off. However, when the electronic expansion valve 16a is fully closed during the heating operation, the refrigerant accumulates in the indoor heat exchanger 12a. Therefore, in order to prevent this, the electronic expansion valve 16a is set to a very small opening to allow a very small amount of the refrigerant to flow. ing.

When the indoor units 2a and 2b are stopped (the outdoor unit 1 and the compressor 3 are stopped), the indoor unit 2a and 2b side electronic expansion valves 16a and 16b are fully opened.

[0010]

The above-mentioned conventional multi-type air conditioner has the following problems to be solved.

That is, in the conventional multi-type air conditioner, when a certain indoor unit is in any of thermo-stop, blow operation, and stop (other indoor units are operating),
For example, in FIG. 2, when the indoor unit 2a is in the above-described state such as a thermo stop and the indoor unit 2b is in operation, the electronic expansion valve 16a of the indoor unit 2a is fully closed during the cooling operation, and the indoor heat during the heating operation. In order to prevent the refrigerant from accumulating in the exchanger 12a, the opening degree is made very small and a small amount of refrigerant is made to flow.

However, there are variations in the accuracy of the electronic expansion valve opening in the minute opening area, and there is a problem that excess capacity of the refrigerant (room temperature rise) and refrigerant flow noise (see note) occur. .

Note: Although there is a refrigerant flow noise during operation, it is canceled by the noise of the blower and does not pose a problem. The blower is stopped during the stop, which may cause a problem.

In order to solve the above problems, the present invention provides a flow path in which a throttle and a check valve are connected in series in parallel with the electronic expansion valve, and the electronic expansion valve is fully closed to accurately detect a small amount of refrigerant in the attached flow path. An object is to provide a heat pump type multi-air conditioner that flows into the air.

[0015]

The present invention is intended to provide a heat pump type multi-air conditioner described in the following (1) and (2) as a means for solving the above problems.

(1). For one outdoor unit equipped with compressor, four-way switching valve, outdoor heat exchanger, and fan,
In a heat pump type multi-air conditioner in which a plurality of indoor units equipped with an electronic expansion valve, an indoor heat exchanger, and a fan are connected, and the plurality of indoor units can be operated individually, in parallel with the electronic expansion valve In addition, a throttle and a check valve are connected in series, and a throttle mechanism for heating operation that flows a set minute refrigerant amount only during heating is installed, and the electronic expansion valve is used for indoor air heating or cooling by an indoor unit. A heat pump type multi air conditioner characterized by being fully closed except when.

(2). The heat pump type multi-air conditioner according to (1) above, wherein the throttle is composed of a capillary tube.

[0018]

Since the present invention is constructed as described above, it has the following actions.

(1). In the above configuration (1), a throttle mechanism for heating operation in which a throttle and a check valve are connected in series is provided in parallel with the electronic expansion valve, and the electronic expansion valve is fully closed except when heating or cooling the indoor air. Therefore, in an indoor unit that does not require cooling / heating of the indoor air, such as when the thermostat is stopped, the air is blown, or is stopped (other indoor units are operating), the electronic expansion valve in the indoor unit is used for both the cooling operation and the heating operation. Is fully closed, and the flow of refrigerant therethrough is shut off.However, during heating operation, a throttle and a check valve that are installed in parallel with the electronic expansion valve are arranged in series for heating operation. It is possible to ensure the flow of a minute predetermined amount of the refrigerant through the throttle mechanism. That is,
Since a very small amount of refrigerant flows accurately through a highly accurate flow path consisting of a throttle and a check valve, excess capacity and flowing noise due to excessive refrigerant flow do not occur as in the past.

Since the check valve is provided in the heating operation throttle mechanism, the flow of the refrigerant is completely shut off during the cooling operation.

(2). In the configuration of (2) above, since the aperture of the configuration of (1) is composed of a capillary tube, a highly accurate and simple aperture can be obtained.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.

The same components as those in the conventional example are designated by the same reference numerals, and the description thereof will be omitted unless necessary.

FIG. 1 is a refrigerant system diagram of the present embodiment. In the figure, a plurality of (two in the figure) indoor units 2a, 2b are provided with electronic expansion valves 16a, 16b in the liquid pipes 15a, 15b.
In parallel with this, heating operation throttle mechanisms 19a and 19b in which throttles composed of capillary tubes 17a and 17b and check valves 18a and 18b are arranged in series are interposed.

However, in any of the indoor units 2a, 2b which does not require cooling / heating of the indoor air, such as when the thermostat is stopped, the air is blown, or stopped, the (indoor units 2a, 2)
b is any other operating condition), for example, the indoor unit 2
a is either a thermo stop, blow operation, stop, etc.,
If the indoor unit 2b is in operation, the electronic expansion valve 16a in the outdoor unit 2a is fully closed during both the cooling operation and the heating operation.

Then, during the cooling operation, the indoor heat exchanger 1
The inflow of the refrigerant into 2a is completely cut off, and the indoor heat exchanger 1
The cooling capacity of 2a can be eliminated.

During heating operation, the heating operation throttle mechanism 19
Since a small predetermined flow rate of the refrigerant flows through a, it is possible to minimize the heating capacity of the indoor heat exchanger 12a and prevent the refrigerant from accumulating inside.

Then, the heating operation throttle mechanisms 19a, 19
The inner diameters and lengths of the capillary tubes 17a and 17b forming b are set so that a predetermined minute refrigerant flow rate is caused to flow, and there is a manufacturing error as in the past due to only the opening degree of the electronic expansion valves 16a and 16b. As a result, there is no variation in the flow rate of the minute refrigerant, and therefore, problems such as excess capacity (room temperature increase) and large refrigerant flow noise due to excessive refrigerant flow do not occur.

Although the capillary tube is used as the diaphragm in this embodiment, the invention is not limited to this, and other suitable diaphragm may be used.

As described above, according to this embodiment, during the heating operation,
When one of the indoor units 2a, 2b is in a thermo-stopped, blown, or stopped state, the electronic expansion valves 16a, 16
Since the corresponding one of b is fully closed, and one of the corresponding throttle mechanisms for heating operation 19a, 19b accurately flows a minute flow rate of the refrigerant, the electronic expansion valves 16a, 16b are required as in the conventional case.
Compared to the case where the corresponding one of
The flow rate accuracy is remarkably high, and there is an advantage that an excessive flow does not cause excess capacity and a large flow noise does not occur.

[0031]

Since the present invention is constructed as described above, it has the following effects.

That is, according to the present invention, a throttle mechanism for heating operation is provided, in which an electronic expansion valve in each indoor unit has a throttle and a check valve arranged in series in parallel with the electronic expansion valve. In an indoor unit that does not require cooling / heating of indoor air such as when the thermostat is stopped or when the air blow operation is stopped (other indoor units are in operation), the electronic expansion valve in the indoor unit is fully operated during cooling operation and heating operation. Since it is closed, the flow of the refrigerant passing through it is blocked, but during heating operation, a small predetermined amount of refrigerant passes through the heating operation throttle mechanism that is interposed in parallel with the electronic expansion valve. The flow of is secured.

The inner diameter and the length of the capillary tube constituting the heating operation throttling mechanism are set so as to flow a predetermined minute refrigerant flow rate, which is the same as in the conventional case in which the minute refrigerant amount is flown by slightly opening the electronic expansion valve. Due to manufacturing errors, the minute refrigerant flow rate does not vary, and the refrigerant does not flow too much. Therefore, problems such as excess capacity (room temperature increase) and refrigerant flow noise due to excessive refrigerant flow do not occur.

Since the check valve is provided in the heating operation throttle mechanism, the inflow of the refrigerant into the indoor heat exchanger is completely shut off during the cooling operation.

[Brief description of drawings]

FIG. 1 is a refrigerant system diagram according to an embodiment of the present invention,

FIG. 2 is a refrigerant system diagram of a conventional heat pump type multi-type air conditioner.

[Explanation of symbols]

 1 outdoor unit 2a, 2b indoor unit 3 compressor 4 four-way switching valve 5 outdoor heat exchanger 12a, 12b indoor heat exchanger 16a, 16b electronic expansion valve 17a, 17b capillary tube 18a, 18b check valve 19a, 19b for heating operation Aperture mechanism

Claims (2)

[Claims] 1. A plurality of indoor units including an electronic expansion valve, an indoor heat exchanger, and a fan, as opposed to one outdoor unit including a compressor, a four-way switching valve, an outdoor heat exchanger, and a fan. In a heat pump type multi-air conditioner that can be connected to each other to individually operate the plurality of indoor units, a throttle and a check valve are connected in series in parallel with the electronic expansion valve, and set only during heating. A heat pump type multi-air conditioner, characterized in that a throttle mechanism for heating operation for flowing a small amount of refrigerant is interposed and the electronic expansion valve is fully closed except when indoor air is heated or cooled by an indoor unit. 2. The heat pump type multi-air conditioner according to claim 1, wherein the throttle is composed of a capillary tube.