JPH06265232A - Device for air conditioning - Google Patents

Abstract

PURPOSE:To ensure in a specified range the degree of supercooling of the refrigerant on the inflow side of the first flow rate-controlling device by a method wherein a first degree of supercooling, calculated from the results of detection by a second pressure detective means and a second temperature detective means, is preset and a second flow rate-controlling device is so controlled as to have the degree of supercooling within the targeted range. CONSTITUTION:A second pressure detective means 16 is provided in a discharge line from a compressor 1 and a second temperature detective means 18 is provided at an intermediate point in a line connecting a heat exchanger 13a and a first flow rate-controlling device 6. A decision is made as regards a targeted range of control of the first degree of supercooling, which is the degree of supercooling at the outlet of a heat source machine calculated from the pressure detected by a second pressure detective means 16 and from the result of detection by a second temperature detective means. This targeted range controls a second flow rate-controlling device 12a. Another pressure detective means 16 and other temperature detective means 17, 19 also control the second flow rate-controlling device 12a. Therefore the flow rate of the refrigerant flowing into an indoor apparatus can be controlled appropriately by a first flow-rate controller 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat source unit having a compressor and a heat source unit side heat exchanger, an indoor side heat exchanger, and a first unit connected to one end corresponding to the heat source unit side heat exchanger. The present invention relates to an air conditioner which is connected by piping to an indoor unit equipped with the flow control device.

[0002]

2. Description of the Related Art A conventional device of this type is shown in FIG. In the figure, A is a heat source unit, and B, C, and D are indoor units connected in parallel with each other, which will be described later, and have the same configuration. Reference numeral 1 is a compressor, 2 is a four-way valve for switching the direction of refrigerant flow, 3 is a heat source unit side heat exchanger, 4 is an accumulator, and a heat source unit A is configured by connecting these devices by piping. 5 are indoor units B, C, D respectively
The indoor side heat exchanger 6 is connected to one end of the indoor side heat exchanger 5 corresponding to the heat source side heat exchanger 3 and is superheated on the refrigerant outlet side of the indoor side heat exchanger 5 during cooling, and is heated during heating. It is the 1st flow control device controlled by the degree of supercooling. 7 is a first connection pipe on the heat source machine side, one end of which is connected to the four-way valve 2, 7b, 7
c and 7d are indoor first connection pipes, one end of which is connected to one end of an indoor unit that serves as an outlet when the indoor heat exchanger 5 is cooled.
Reference numeral 9 denotes the other end of the first connection pipe 7 on the heat source device side and the first end on the indoor side.
Of the connection pipes 7b, 7c, 7d of the first connection point, 8 is the second connection pipe of the heat source unit side, 8b, 8c, whose one end is connected to the heat source unit side heat exchanger 3 8d is a second connection pipe on the indoor side, one end of which is connected to the first flow control device 6, 10 is the other end of the second connection pipe 8 on the heat source device side, and a second connection pipe 8b on the indoor side, It is a second connection point that connects the other ends of 8c and 8d. In the figure, solid arrows indicate the flow direction of the refrigerant during the cooling operation, and dashed arrows indicate the flow direction of the refrigerant during the heating operation.

Next, the operation during the cooling operation will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the heat source unit side heat exchanger 3 via the four-way valve 2 and exchanges heat with outdoor air or the like to be liquefied. The liquefied liquid refrigerant reaches the second connection point 10 through the second connection pipe 8 on the heat source unit side, is branched there, and passes through the second connection pipes 8b, 8c, 8d on the indoor side to the indoor unit B, respectively. It flows into C and D. The refrigerant flowing into each of the indoor units B, C, D is decompressed to a low pressure by the first flow rate control device 6 controlled by the superheat degree of the outlet of the indoor heat exchanger 5, and the indoor air in the indoor heat exchanger 5 is reduced. It heats and evaporates and is gasified to cool the room. The refrigerant in the gas state is used for the first connection pipe 7 on the indoor side.
b, 7c, 7d and merge at the first connection point 9, and the first connection pipe 7 on the heat source machine side, the 4-way valve 2, the accumulator 4
After that, it is sucked into the compressor 1. In this way, the refrigeration cycle is formed.

Next, the operation during the heating operation will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 reaches the first connection point 9 via the four-way valve 2 and the first connection pipe 7 on the heat source device side, and is branched here to be divided into the first indoor side. Connection pipe 7
After passing through b, 7c and 7d, they flow into the indoor units B, C and D, respectively. The refrigerant that has flowed into each of the indoor units B, C and D exchanges heat with the indoor air in the indoor heat exchanger 5 and is condensed and liquefied to heat the room. Then, the refrigerant in the liquid state is depressurized to a low pressure by the first flow rate control device 6 controlled by the degree of supercooling at the outlet of the indoor heat exchanger 5, and the indoor second connection pipe 8b, After joining 8c and 8d at the second connection point 10, they flow through the second connection pipe 8 on the heat source machine side into the heat exchanger 3 on the heat source machine side, where they exchange heat with outdoor air or the like and are gasified. To do. The gasified gas refrigerant is sucked into the compressor 1 via the four-way valve 2 and the accumulator 4. In this way, the refrigeration cycle is formed.

[0005]

Since the conventional air conditioner is configured as described above, in the cooling operation, when the indoor unit is installed above the heat source unit, the heat source unit is not installed. While the refrigerant liquefied in the side heat exchanger rises in the second connection pipe on the heat source unit side, it becomes a gas-liquid two-phase state due to the pressure drop of the liquid head, and the flow rate of the refrigerant flowing into the indoor unit is first However, there is a problem that it is difficult to control the flow rate control device. Further, in the cooling operation, when the second connection pipe on the heat source device side and the second connection pipe on the indoor side are long, the refrigerant liquefied in the heat source device side heat exchanger is connected to the second connection pipe on the heat source device side. It is difficult to control the flow rate of the refrigerant flowing into the indoor unit into the gas-liquid two-phase state due to the pressure drop due to the friction loss while flowing through the pipe and the second connection pipe on the indoor side by the first flow rate control device. There was a problem that became. Further, in the cooling operation, when the refrigerant charge amount is large, the first flow rate control device controls the outlet of the indoor heat exchanger to be in an overheated state, and thus the excess refrigerant is stored in the accumulator. Not distributed, but distributed in the heat source side heat exchanger. Therefore, the proportion of the liquid refrigerant in the heat source side heat exchanger increases, the heat exchange amount in the heat source side heat exchanger decreases, the high pressure rises, and the pressure switch (such as the discharge pipe of the compressor) ( However, there is a problem in that (not shown) operates abnormally and the power consumption of the compressor increases. Further, in the cooling operation, the discharge temperature of the compressor is changed when the compressor operates at a high compression ratio, when the compressor is overloaded at high pressure and low pressure, or when the refrigerant is running low. There is a problem that the reliability of the compressor is remarkably deteriorated because the temperature rises excessively and the life is remarkably shortened.

In the heating operation, when the load on the indoor unit side is small and the load on the heat source unit side heat exchanger is large (in the case of an air-cooling type heat exchanger, the suction air temperature of the heat exchanger, the water cooling type). If the inlet water temperature of the heat exchanger is high, etc.), the discharge pressure of the compressor rises and the pressure switch (not shown) provided in the discharge pipe of the compressor, etc.
However, there was a problem that continuous operation was impossible, such as the fact that it operated and stopped abnormally. In the heating operation, the discharge temperature of the compressor changes when the compressor operates at a high compression ratio, when the compressor is overloaded at high pressure or low pressure, or when the refrigerant is running low. There is a problem that the reliability of the compressor is remarkably deteriorated because the temperature rises excessively and the life is remarkably shortened. The present invention has been made to solve the above problems, and in the cooling operation, even when the indoor unit is installed above the heat source unit, it is liquefied by the heat source unit side heat exchanger. Even if there is a pressure drop for the liquid head while the refrigerant is rising in the second connection pipe on the heat source unit side,
Even when the second connection pipe on the heat source unit side and the second connection pipe on the indoor side are long, the refrigerant liquefied in the heat exchanger on the heat source unit side is connected to the second connection pipe on the heat source unit side and the indoor side. Even if there is a pressure drop due to friction loss while flowing through the second connecting pipe, the liquid state is not maintained but the gas-liquid two-phase state is maintained, and the flow rate of the refrigerant flowing into the indoor unit is controlled by the first flow rate control. An object is to obtain an air conditioner that can be easily controlled by the device. Further, another invention of the present invention is that in the cooling operation, even when the refrigerant charge amount is large, the ratio of the liquid refrigerant of the heat source side heat exchanger does not increase so much, and therefore the high pressure does not rise and is abnormal. An object of the present invention is to obtain an air conditioner that does not stop and the power consumption of the compressor does not increase. Another object of the present invention is to obtain an air conditioner with high reliability of the compressor in the cooling operation without constantly raising the discharge temperature of the compressor.

Another aspect of the present invention is that, in heating operation, the load on the indoor unit side is small and the load on the heat source unit side heat exchanger is large (heat exchange in the case of an air-cooling type heat exchanger). Even if the suction air temperature of the compressor and the inlet water temperature of the heat exchanger in the case of a water-cooled heat exchanger are high), the discharge pressure of the compressor does not rise and continuous operation without abnormal stop is possible. The purpose is to obtain a possible air conditioner. Another object of the present invention is to obtain an air conditioner with a highly reliable compressor, in which the discharge temperature of the compressor does not always rise excessively during heating operation.

[0008]

According to a first aspect of the present invention, there is provided an air conditioner, which is a heat source machine having a compressor and a heat source side heat exchanger, an indoor heat exchanger, and the indoor heat exchanger. In a refrigerant circuit in which an indoor unit having a first flow rate controller connected to one end corresponding to the heat source machine side heat exchanger is pipe-connected, the heat source machine side heat exchanger and the first flow rate control A bypass pipe branching from the middle of the pipe connecting the device and reaching the suction side low-pressure pipe of the compressor via the second flow rate control device; one end of the bypass pipe on the compressor side; and the second pipe.
And a heat exchange section for exchanging heat between the heat source unit side heat exchanger and the pipe connecting the first flow rate control device, and the discharge of the compressor. From the detected pressure detected by the second pressure detecting means provided in the pipe and the detected temperature detected by the second temperature detecting means provided between the heat exchange section and the first flow rate control device. The cooling-time flow rate control device control means for controlling the second flow rate control device is provided so that the calculated first subcooling degree falls within a preset target range.

An air conditioner according to a second aspect of the present invention further comprises height difference input means for inputting in accordance with the height difference between the heat source unit side heat exchanger and the indoor unit mounting position,
The subcooling degree control target range determining means for determining the target range of the first supercooling degree according to the input value of the height difference inputting means is provided. An air conditioner according to claim 3 of the present invention is provided with a pipe length input means for inputting in accordance with a length of a connection pipe connecting the heat source unit and the indoor unit, and an input value of the pipe length input unit is set. Accordingly, the subcooling degree control target range determining means for determining the target range of the first supercooling degree is provided.

According to a fourth aspect of the present invention, there is provided an air conditioner comprising a compressor, a heat source side heat exchanger, an indoor side heat exchanger, and the indoor side heat exchanger. In a refrigerant circuit in which an indoor unit having a first flow rate control device connected to one end corresponding to an exchanger is connected by piping, a pipe connecting the heat source unit side heat exchanger and the first flow rate control device Detected pressure detected by the second pressure detecting means provided in the bypass pipe branched from the middle and reaching the suction side low pressure pipe of the compressor through the second flow rate control device and the discharge pipe of the compressor. And the second degree of supercooling calculated from the detected temperature detected by the third temperature detecting means provided in the pipe connecting the heat source side heat exchanger and the first flow rate control device. Cooling-time flow rate control device control for controlling the second flow rate control device It is provided with a means. An air conditioner according to claim 5 of the present invention includes a heat source device including a compressor and a heat source device side heat exchanger, an indoor heat exchanger, and the heat source device side heat exchanger of the indoor heat exchanger. In a refrigerant circuit in which an indoor unit having a first flow rate control device connected to one end corresponding thereto is connected by piping, a branch is made from the middle of the pipe connecting the heat source unit side heat exchanger and the first flow rate control device. A bypass pipe that reaches the suction-side low-pressure pipe of the compressor via the second flow control device, and a pipe that connects the compressor-side end of the bypass pipe and the second flow control device, With a heat exchange section for exchanging heat between the heat source unit side heat exchanger and a pipe connecting the first flow rate control device, and a fourth temperature detecting means provided in the discharge pipe of the compressor. When the detected temperature detected exceeds a preset temperature, the second flow It is provided with a a cooling time of the flow control device control means for increasing the opening degree of the control device.

An air conditioner according to a sixth aspect of the present invention is a heat source device comprising a compressor, a switching valve, a heat source side heat exchanger, an indoor side heat exchanger, and the indoor side heat exchanger. In a refrigerant circuit in which an indoor unit having a first flow rate control device connected to one end corresponding to the machine side heat exchanger is pipe-connected, the heat source device side heat exchanger and the first flow rate control device are connected to each other. A second pipe provided in the discharge pipe of the compressor, and a bypass pipe connecting the connecting pipe, the pipe connecting the switching valve and the indoor heat exchanger via a third flow control device. Of the second pressure detection means and the second
The heating-time flow rate control device control means for controlling the opening degree of the third flow rate control device based on the pressure detected by the pressure detection device.

An air conditioner according to a seventh aspect of the present invention is a heat source device comprising a compressor, a switching valve, a heat source side heat exchanger, an indoor side heat exchanger, and the indoor side heat exchanger. In a refrigerant circuit in which an indoor unit having a first flow rate control device connected to one end corresponding to the machine side heat exchanger is pipe-connected, the heat source device side heat exchanger and the first flow rate control device are connected to each other. The bypass pipe connecting the connecting pipe, the pipe connecting the switching valve and the indoor heat exchanger via the third flow control device, and the discharge pipe of the compressor at the fourth temperature. A heating time flow rate control device control means for controlling the opening degree of the flow rate control device to increase when the temperature detected by the fourth temperature detection device exceeds a set temperature during heating operation. Is provided.

[0013]

In the air conditioner according to the first aspect of the present invention, during the cooling operation, a part of the liquid refrigerant liquefied in the heat source side heat exchanger flows into the bypass pipe to a low pressure by the second flow control device. It is decompressed and becomes a low-temperature gas-liquid two-phase state. Flows into the accumulator. On the other hand, the high temperature liquid refrigerant liquefied in the heat source side heat exchanger is sufficiently supercooled by the low temperature gas-liquid two-phase refrigerant whose pressure is reduced to a low pressure by the second flow rate control device in the heat exchange section, and The pressure detected by the second pressure detecting means provided in the discharge pipe and the detected temperature detected by the second temperature detecting means provided between the heat exchange section and the first flow rate control device. Even if the indoor unit is installed above the heat source unit, the second flow rate control device is controlled so that the first degree of supercooling calculated from the above becomes a preset target range. Even if there is a pressure drop for the liquid head while the refrigerant liquefied in the heat exchanger on the heat source unit side is rising in the second connecting pipe on the heat source unit side, the second connecting pipe on the heat source unit side , The pressure of the friction loss while flowing through the indoor second connection pipe Even the lower retaining the liquid material does not become a gas-liquid two-phase state.

In the air conditioner according to the second aspect of the present invention, during the cooling operation, the target range of the first degree of subcooling is determined according to the height difference between the heat source unit side heat exchanger and the indoor unit mounting position. Is determined and the second flow rate control device is controlled, the refrigerant liquefied in the heat source unit side heat exchanger is liquefied in the heat source unit side even when the indoor unit is installed above the heat source unit. When the connection pipe of No. 2 is rising, even if there is a pressure drop for the liquid head, the gas-liquid two-phase state is not obtained and the liquid state is maintained.

In the air conditioner according to claim 3 of the present invention, during the cooling operation, the target range of the first degree of subcooling is determined according to the length of the connecting pipe connecting the heat source unit and the indoor unit. Is determined and the second flow rate control device is controlled, there is a pressure drop corresponding to the friction loss while flowing through the second connection pipe on the heat source unit side and the second connection pipe on the indoor side. Holds the liquid state without becoming the gas-liquid two-phase state.

In the air conditioner according to the fourth aspect of the present invention, during the cooling operation, part of the refrigerant liquefied in the heat source side heat exchanger flows into the second flow rate control device and flows into the accumulator. When the proportion of the liquid refrigerant in the heat source unit side heat exchanger increases, the second refrigerant provided in the discharge pipe of the compressor
Calculated from the detected pressure detected by the pressure detecting means and the detected temperature detected by the third temperature detecting means provided in the pipe connecting the heat source side heat exchanger and the first flow rate control device. Since the degree of supercooling of No. 2 becomes large, the opening degree of the second flow rate control means is adjusted so that a part of the liquid refrigerant in the heat source side heat exchanger is bypassed to the accumulator via the second flow rate control device. Therefore, the proportion of the liquid refrigerant in the heat source unit side heat exchanger is kept within a certain range.

In the air conditioner according to the fifth aspect of the present invention, when the temperature detected by the fourth temperature detecting means provided in the discharge pipe of the compressor rises during the cooling operation, the opening degree of the second flow control device is changed. Of the liquid refrigerant that has been adjusted and liquefied in the heat source side heat exchanger, the amount that flows into the accumulator through the second flow rate control device can be increased to lower the suction temperature of the compressor, and the discharge temperature of the compressor can be reduced. Also decreases.

In the air conditioner according to claim 6 of the present invention, when the pressure detected by the second pressure detecting means rises during the heating operation, one of the high-temperature and high-pressure gas refrigerant discharged from the compressor and passing through the switching valve. The portion flows into the bypass pipe by an appropriate amount by the third flow rate control device, is reduced to a low pressure by the third flow rate control device, and merges with the refrigerant that has passed through the indoor unit.

In the air conditioner according to claim 7 of the present invention, when the temperature detected by the fourth temperature detecting means provided in the discharge pipe of the compressor rises during the heating operation, the temperature is discharged from the compressor, Of the high-temperature and high-pressure gas refrigerant that has passed through the switching valve, the amount that passes through the third flow rate control device can be increased, and the discharge temperature of the compressor can also be reduced.

[0020]

【Example】

Example 1. An embodiment of the present invention will be described below. FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to an embodiment of the present invention. In the figure, A,
B, C, D and 1,3,4,5,6,7,7b, 7c,
7d, 8, 8b, 8c, 8d, 9 and 10 are the same as those of the conventional air conditioner shown in FIG. 9, and the description thereof is omitted here. Reference numeral 2 is a switching valve, and a 4-way valve is used in this embodiment. 11a is the heat source unit side heat exchanger 3 and the first
Bypass pipe connecting the pipe connecting to the flow control device 6 and the pipe connecting the four-way valve 2 which is the suction side low pressure pipe of the compressor and the accumulator 4, 12a indicates the bypass pipe 1
A second flow rate control device (here, an electric expansion valve) provided in the middle of the pipe 1a, and a pipe 13a connecting the heat source unit side heat exchanger 3 and the branch portion 11c of the bypass pipe 11a,
A heat exchange part for exchanging heat between the second flow rate control device 12a of the bypass pipe 11a and a pipe portion between one end of the bypass pipe 11a and the compressor 1, and 14 is an intermediate pipe connecting the four-way valve 2 and the accumulator 4. Is a first pressure detecting means, 15 is a first temperature detecting means provided in the middle of the pipe between the heat exchange part 13a and one end of the bypass pipe 11a on the compressor 1 side, 16
Is a second pressure detecting means provided in the discharge pipe of the compressor 1, 17 is a third temperature detecting means provided in the middle of the pipe connecting the heat source unit side heat exchanger 3 and the heat exchange section 13a, 18
Is a second temperature detecting means provided in the middle of the pipe connecting the heat exchange section 13a and the first flow rate control device 6,
Reference numeral 9 is a fourth temperature detecting means provided in the discharge pipe of the compressor 1.

The solid line arrows in the figure indicate the direction of the refrigerant flow during the cooling operation, and the broken line arrows indicate the direction of the refrigerant flow during the heating operation. The operation on the refrigerant side during the heating operation is completely the same as that of the conventional air conditioner shown in FIG. The operation on the refrigerant side during the cooling operation is exactly the same as that of the conventional air conditioner shown in FIG. 9 except for the portions related to the heat exchange section 13a and the bypass pipe 11a, and therefore the description thereof is omitted. A portion related to 13a and the bypass pipe 11a will be described. That is, the liquid refrigerant liquefied in the heat source unit side heat exchanger 3 passes through the heat exchange section 13a, and then a part thereof flows into the bypass pipe 11a and is depressurized to a low pressure by the second flow rate control device 12a. It becomes a two-phase state, merges with the refrigerant gasified in the heat exchange section 13a and gasified in the indoor heat exchanger 5, and flows into the accumulator 4. On the other hand, in the heat exchange section 13a, the high temperature liquid refrigerant liquefied in the heat source unit side heat exchanger 3 is sufficiently cooled by the low temperature refrigerant flowing through the bypass pipe 11a to become a liquid refrigerant with a high degree of supercooling, and a part of it is The remaining refrigerant flowing into the bypass pipe 11a flows into the second connection pipe 8 on the heat source machine side and reaches the second connection point 10. Since it is a liquid refrigerant that is sufficiently cooled in the heat exchange section 13a and has a large degree of supercooling, the indoor units B, C, and D are different from the heat source unit A.
Even if it is installed above the liquid head, even though there is a pressure drop corresponding to the liquid head, the gas is not in the gas-liquid two-phase state at the second connection point 10 and the inlet portion of each first flow rate control device 6, The state can be maintained, and the flow rate of the refrigerant flowing into each indoor unit B, C, D can be easily controlled by the first flow rate control device 6. In addition, since the liquid refrigerant is sufficiently cooled in the heat exchange section 13a and has a large degree of supercooling, the second connection pipe 8 on the heat source unit side and the second connection pipes 8b, 8c, 8d on the indoor side are connected. Even if the length is long, despite the pressure drop due to friction, the second connection point 10 and the inlet portion of each first flow rate control device 6 do not become a gas-liquid two-phase state but maintain a liquid state. Therefore, the flow rate of the refrigerant flowing into each indoor unit B, C, D can be easily controlled by the first flow rate control device 6. In addition, when excess refrigerant is generated (when the refrigerant is overfilled, etc.), the bypass pipe 11a from the high pressure liquid line to the accumulator 4 is increased by slightly increasing the opening degree of the second flow rate control device 12a. It becomes a liquid bypass, the ratio of the liquid refrigerant in the heat source unit side heat exchanger 3 decreases, and the surplus refrigerant is distributed to the accumulator 4. Therefore, the heat source side heat exchanger 3
The amount of heat exchange of the compressor increases, the high pressure decreases, and the power consumption of the compressor decreases.

When the opening degree of the second flow control device 12a is slightly increased, the bypass pipe 11a is
Since it becomes a liquid bypass from the high-pressure liquid line to the accumulator 4, the superheat degree of the suction gas refrigerant of the compressor 1 decreases and the discharge temperature of the compressor 1 also decreases. Therefore, the compressor 1
It is possible to suppress the decrease in the life of the compressor and improve the reliability of the compressor 1. Next, the control content of the second flow rate control device 12a during the cooling operation will be described with reference to the block diagram shown in FIG. 20 is a height difference input means for inputting the height difference (difference in installation height) between the heat source unit A and the indoor units B, C, D, 21 is the second connection pipe 8 on the heat source unit side, and the second connection pipe on the indoor side. It is a pipe length input means for inputting the lengths of the connection pipes 8b, 8c, 8d. A heat source unit 22 is calculated from the detected pressure of the second pressure detection unit 16 and the detected temperature of the second temperature detection unit 18 according to the input value of the height difference input unit 22 and the input value of the pipe length input unit 21. control target range in the first degree of subcooling SC _c is the degree of subcooling at the outlet of the a (upper limit value SC _c1 and the lower limit value SC _c2)
The subcooling degree control target range determining means, which determines the cooling degree, 23 is a cooling-time flow rate control device controlling means, and the first pressure detecting means 1
Based on the superheat degree SH ₀ at the outlet of the heat exchange section 13a of the refrigerant flowing through the bypass pipe 11a calculated from the detected pressure of No. 4 and the detected temperature of the first temperature detecting means 15, the first supercooling degree SC _c is SC. The second pressure control device 12a is controlled so that _c1 ≧ SC _c ≧ SC _c2 , and the second pressure detecting means 1
The second degree of supercooling SC ₀ , which is the degree of supercooling at the outlet of the heat source unit side heat exchanger 3 calculated from the detected pressure of 6 and the temperature detected by the third temperature detecting means 17, does not exceed the upper limit value SC _0max . (That is, SC ₀ ≦ SC _0max ) so that the second flow rate control device is controlled so that the temperature T _d detected by the fourth temperature detecting means 19 does not exceed the upper limit value T _dmax (that is, T The second flow control device 12a so that _d ≦ T _dmax )
Is to control.

The first degree of supercooling SC _c required to maintain the liquid state at the second connection point 10 and the inlet of each first flow rate control device 6 is determined by the heat source unit A and the indoor units B, C. , D, and the lengths of the second connection pipe 8 on the heat source device side and the second connection pipes 8b, 8c, 8d on the indoor side, the height difference is input to the height difference input means 20. , The pipe length is inputted to the pipe length input means 21, and the control target range (upper limit value SC _c1 , lower limit value) of the first supercooling degree SC _c is inputted from the respective input values by the supercooling degree control target range determining means 22. SC _c2 ) is determined. Further, it shows a relationship between the opening and the first subcooling degree SC _c of the second flow rate control device 12a in FIG. When the opening degree of the second flow rate control device 12a is small, the flow rate of the refrigerant flowing through the bypass pipe 11a is small, so that the superheat degree SH _{0 at} the outlet of the heat exchanging portion 13a of the bypass pipe 11a is large, and the heat exchanging portion 13a.
The proportion of the superheated gas on the side of the bypass pipe 11a of a is large. Therefore, the amount of heat exchange in the heat exchange section 13a is small, and the first degree of supercooling SC _c is small. That is, SH ₀
In a large area, when the opening degree of the second flow rate control device 12a is decreased, the flow rate of the refrigerant flowing through the bypass pipe 11a is decreased, and the ratio of SH ₀ and the superheated gas on the bypass pipe 11a side of the heat exchange section 13a is increased. As a result, the amount of heat exchange decreases, so the first degree of supercooling SC _c decreases, but conversely, when the opening degree of the second flow rate control device is increased, the flow rate of the refrigerant flowing through the bypass pipe 11a increases, and SH ₀ and The first supercooling degree SC _c increases because the proportion of the superheated gas on the bypass pipe 11a side of the heat exchange section 13a decreases and the heat exchange amount increases (the "superheat region" on the left side of the alternate long and short dash line in FIG. 3). ). On the other hand, when the opening degree of the second flow rate control device 12a is large,
Because the flow rate of the refrigerant flowing through the bypass pipe 11a is large.

The outlet of the heat exchange section 13a of the bypass pipe 11a becomes wet, and the bypass pipe 1 of the heat exchange section 13a
There is no superheated gas portion on the 1a side, but bypass piping 11a
That the outlet of the heat exchange section 13a is wet means that it is a gas-liquid two-phase flow, and friction in the pipe downstream of the heat exchange unit 13a of the bypass pipe 11a is greater than that in the case where there is a superheated gas portion. The pressure loss due to the loss is large. When the opening degree of the second flow rate control device 12a increases in this region, as the refrigerant flowing through the bypass pipe 11a increases,
The pressure loss due to friction loss in the downstream portion of the heat exchange section 13a of the bypass pipe 11a rapidly increases, and the bypass pipe 11a
The representative pressure (static pressure) of the heat exchange section 13a increases, the temperature on the low temperature side of the heat exchange section 13a increases, and the heat exchange amount decreases. As a result, the first supercooling degree SC _c decreases. However, conversely, when the opening degree of the second flow rate control device 12a decreases, the flow rate of the refrigerant flowing through the bypass pipe 11a decreases, so that the pressure loss due to the friction loss in the downstream portion of the heat exchange section 13a of the bypass pipe 11a is small, and Piping 11
The temperature on the upstream side of “a” also decreases, and the heat exchange amount increases. As a result, the first supercooling degree SC _c increases (“wet area” on the right side of the alternate long and short dash line in FIG. 3). Further, in this region (region where the outlet of the heat exchange unit 13a of the bypass pipe 11a is in a wet state), when the opening degree of the second flow rate control device 12a increases, a flow rate larger than the amount that can be evaporated in the heat exchange unit 13a is generated. The liquid refrigerant supplied to the bypass pipe 11a and distributed in the condensing part comes to be distributed in the low pressure part, and is no longer in a liquid single-phase state between the heat source unit side heat exchanger 3 and the heat exchange part 13a.
Becomes entrained gas-liquid two-phase state of gas, the heat exchange amount of the heat exchange portion 13a is not increased, the degree of supercooling that is, the first degree of subcooling SC _c of the outlet of the heat exchange portion 13a is reduced. Further, in this region, when the opening degree of the second flow rate control device 12a is decreased, the liquid refrigerant distributed in the low pressure part is distributed in the condensing part, and the heat source unit side heat exchanger 3 and the heat exchanging part 13a. the refrigerant state between the reduced gas component, the first degree of subcooling SC _c increases. From the above characteristics, if SH ₀ is greater than a certain value SH _B (SH ₀ > SH _B ), it is determined that the temperature is in the “overheat region”, and if SC _c <SC _c2 , the second flow rate is determined. If the opening degree of the control device 12a is increased to _satisfy SC _c ≧ SC _c2 and SC _c > SC _c1 , the opening degree of the second flow rate control device 12a is decreased to SC.
By setting _c ≤SC _c1 , the first supercooling degree SC _c can be set within the control target range. If SH ₀ is below a certain value (SH ₀ ≦ SH _B ), it is determined that the condition is “wet”, and SC _c <SC _c2 , the opening of the second flow control device 12a. To reduce SC _c ≧ S
If C _c2 and SC _c > SC _c1 , then the opening degree of the second flow rate control device 12a is increased to _satisfy SC _c ≦ SC _c1 so that the first supercooling degree SC _c falls within the control target range. Can be

Next, the control contents of the cooling-time flow rate control device control means 23 will be described with reference to the flowchart of FIG. In step 51, SH ₀ is calculated from the detected pressure of the first pressure detecting means 14a and the detected temperature of the first temperature detecting means 15, and the detected pressure of the second pressure detecting means 16 and the second temperature detecting means 18 are calculated. The first supercooling degree SC _c is calculated from the detected temperature of No. 2, and the second supercooling degree Sc ₀ is calculated from the detected pressure of the second pressure detecting means 16 and the detected temperature of the third temperature detecting means 17. Proceed to step 52. In step 52, the detected temperature T _{d of} the fourth temperature detecting means 19 is set to the preset upper limit value T.
_It is determined whether or not it is larger than _dmax. If T _d > T _dmax , the _routine proceeds to step 53, where the opening of the second flow control device 12a is increased, and if T _{d ≤T dmax, the routine} proceeds to step 54. In step 54, it is determined whether the second degree of supercooling SC ₀ is larger than a preset upper limit value SC _0max , and SC ₀ > SC.
If it is _0max , the _routine proceeds to step 55, where the second flow rate controller 12
The opening degree of a is increased, and if SC ₀ ≦ SC _0max , step 5
Go to 6. In step 56, it is determined whether or not greater than SH _B which SH ₀ is set in advance, the process proceeds to SH _0> SH _B If step 57, the process proceeds to SH ₀ ≦ SH _B if step 62. In step 57, the first supercooling degree SC _c
Is greater than the upper limit value SC _c1 of the control target range determined by the supercooling degree control target range determining means 22, and if SC _c > SC _c1 , the process proceeds to step 58, and the second flow rate controller 12a Is decreased, and if SC _c ≦ SC _c1 , the _routine proceeds to step 59. In step 59, it is judged whether or not the first supercooling degree SC _c is smaller than the lower limit value SC _c2 of the control target range determined by the supercooling degree control target range determining means 22. If SC _c <SC _c2 , step 60, the opening degree of the second flow rate control device 12a is increased, and SC _c
If ≧ SC _c2 , the _routine proceeds to step 61, where the opening of the second flow control device 12a is maintained. On the other hand, in step 62, the first subcooling degree SC _c is the subcooling degree control target range determining means 2
It is determined whether or not it is larger than the upper limit value SC _c1 of the control target range determined by 2. If SC _c > SC _c1 , step 6
3 to increase the opening degree of the second flow rate control device 12a,
If SC _c ≤SC _c1 , the process proceeds to step 64. Step 6
4, the first supercooling degree SC _c is the lower limit value SC of the control target range determined by the supercooling control target range determining means 22.
_It is determined whether or not it is smaller than _{c2, and} if SC _c <SC _c2 , the _routine proceeds to step 65, where the opening of the second flow control device 12a is decreased, and if SC _c ≧ SC _c2 , the _routine proceeds to step 66, where the second The opening degree of the flow rate control device 12a is maintained. Step 5
2nd at 3,55,58,60,61,63,65,66
After increasing / decreasing / maintaining the opening degree of the flow control device 12a, the process returns to step 51 again.

Example 2. Hereinafter, the first embodiment of the present invention will be described.
Another embodiment different from the above will be described. 5 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a second embodiment of the present invention, FIG. 6 is a control block diagram during heating operation, and a control block diagram during cooling is shown in FIG. Same as).
In the figure, A, B, C, D and 1, 3, 4, 5, 6,
7,7b, 7c, 7d, 8,8b, 8c, 8d, 9,1
No. 0 is the same as the conventional air conditioner shown in FIG. 9, and the description thereof is omitted here. Reference numeral 2 is a switching valve, and a four-way valve is used in this embodiment. Reference numeral 11b is a bypass pipe connecting the heat source unit side heat exchanger 3 and the first flow rate control device 6 with a pipe connecting the four-way valve 2 and the indoor side heat exchanger 5, and 12b is a bypass pipe. A third flow rate control device (here, an electric expansion valve) provided in the middle of the pipe 11b, 13b is a pipe connecting the heat source unit side heat exchanger 3 and the first flow rate control device 6, and a bypass pipe 11b. Of the third flow rate control device 12b and one end on the side of the four-way valve 2 for exchanging heat with each other, 14 to 23 are the first embodiment.
Since it is the same as, the description is omitted here. Reference numeral 24 is a heating-time flow rate control device control means for controlling the third flow rate control device 12b based on the output signal of the second pressure detection means 16 and the output signal of the second temperature detection means 19 during the heating operation.

The solid arrows in the figure indicate the direction of refrigerant flow during cooling operation, and the broken arrows indicate the direction of refrigerant flow during heating operation. The operation on the refrigerant side during the cooling operation is the same as that of the air conditioner of the first embodiment shown in FIG. The operation on the refrigerant side during the heating operation is exactly the same as that of the conventional air conditioner shown in FIG. 9 except for the portions related to the heat exchange section 13b and the bypass pipe 11b, and therefore the description thereof is omitted. A portion related to 13b and the bypass pipe 11b will be described. That is, when the load on the indoor unit side is small and the load on the heat source unit side heat exchanger is large (in the case of an air-cooled heat exchanger, the intake air temperature of the heat exchanger, and in the case of a water-cooled heat exchanger, When the inlet water temperature of the heat exchanger is high), the third flow rate control device 12b is controlled by the heating flow rate control device control means 24 so that the pressure detected by the second pressure detection means 16 falls within a certain range. Then, a part of the high-temperature high-pressure gas refrigerant discharged from the compressor 1 and passing through the 4-way valve 2 flows into the bypass pipe 11b, and the indoor units B, C, and D are connected to the second connection pipe 8 on the indoor side.
b, 8c, 8d, the second connection pipe 10, the second heat source device side
The low-temperature low-pressure gas-liquid two-phase refrigerant that has flowed into the heat source unit A through the connection pipe 8 and is condensed and liquefied by the heat exchange section 13b.
After the pressure is reduced by the third flow rate control device 12b, the indoor units B, C,
It joins the gas-liquid two-phase refrigerant flowing from D into the heat source unit A. As a result, since a part of the refrigerant is condensed in the heat exchange section 13b, there is the same effect as if the load on the indoor unit side increased by acting as if the condenser increased, so the discharge pressure of the compressor was increased. It is possible to operate continuously without abnormal stop without rising. Further, when the discharge temperature of the compressor 1 exceeds the upper limit value, the heating-time flow rate control device control means 24 causes the third time.
Of the high-temperature high-pressure gas refrigerant discharged from the compressor 1 and passing through the four-way valve 2 flows into the bypass pipe 11b and is discharged from the indoor units B, C, D The low-temperature low-pressure gas-liquid two-phase refrigerant that has flowed into the heat source unit A via the second inner connecting pipes 8b, 8c, 8d, the second connecting point 10, and the second connecting pipe 8 on the heat source unit side, and the heat exchange section. The heat is exchanged in 13b to be condensed and liquefied, the pressure is reduced in the third flow rate control device 12b, and the refrigerant is combined with the gas-liquid two-phase refrigerant flowing from the indoor units B, C, and D into the heat source unit A. As a result, since a part of the refrigerant is condensed in the heat exchange section 13b, there is the same effect as if the load on the indoor unit side increased by acting as if the condenser increased, so the discharge pressure of the compressor was increased. And the discharge temperature are also reduced, the life of the compressor is not shortened, and the reliability of the compressor is significantly improved.

Next, the control contents of the third flow rate control device control means 24 will be described with reference to the flowchart of FIG. FIG. 7 is a flowchart showing the control contents of the heating-time flow rate control device control means 24. In step 41, it is determined whether the detected pressure P _{d of} the second pressure detecting means 16 is larger than the preset first set pressure P ₁ or the detected temperature T _{d of} the fourth temperature detecting means 19 is preset. _Is determined to be greater than the upper limit value T _dmax , and at least P _d > P ₁ or T
If either _d > T _dmax, the _routine proceeds to step 42, where the opening degree of the third flow rate control device 12b is increased, and then step 41
Returning to step 4, if P _{d ≤P 1} and T _{d ≤T dmax} , step 4
Go to 3. Proceed to the second set pressure P ₂ to determine a smaller or not P _d <P ₂ if step 44 In step 43 P _d is set smaller than the first set pressure P ₁ in advance third flow rate The opening degree of the control device 12b is decreased and the process returns to step 41. If P _d > P ₂ , the third flow rate control device 12
The opening of b is left unchanged, and the process returns to step 41. In this way, the third flow rate controller 12b and the second pressure detecting means 16 for detecting the pressure P _d is constant range and the heating time of the flow control device controlling means as the discharge temperature of the compressor is equal to or less than the upper limit value Controlled by 24.

Example 3. In the above embodiment, the first connection pipe 7 on the heat source device side and the first connection pipes 7b, 7 on the indoor side are provided.
c and 7d are connected at one point of the first connection point 9, and the second connection pipe 8 on the heat source unit side and the second connection pipe 8 on the indoor side
Although b, 8c, and 8d are connected at one point of the second connection point 10, as shown in FIG.
Even when there are a plurality of connecting points, the same operational effect is obtained.

Embodiment 4 In the above embodiment, three indoor units are connected to one heat source unit, but the number of indoor units may be one, or
Similar effects can be obtained with two or more than four units.

[0031]

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

In the air conditioner according to claim 1,
A bypass pipe that branches from the middle of the pipe connecting the heat source side heat exchanger and the first flow rate control device and reaches the suction side low pressure pipe of the compressor via the second flow rate control device; A heat exchange section for exchanging heat between a pipe connecting one end of the compressor and the second flow rate control device and a pipe connecting the heat source side heat exchanger and the first flow rate control device; A pressure detected by a second pressure detecting means provided in the discharge pipe of the compressor, and a second temperature detecting means provided between the heat exchange section and the first flow rate control device. By providing the cooling-time flow rate control device control means for controlling the second flow rate control device so that the first degree of supercooling calculated from the detected temperature is within the preset target range, The first flow rate control device always ensures the degree of supercooling of the inflow side refrigerant within a predetermined range Rukoto can, the flow rate of refrigerant flowing into the indoor unit can be accurately controlled by the first flow rate controller.

In the air conditioner according to claim 2,
Further, a height difference input means for inputting according to the height difference between the heat source side heat exchanger and the indoor unit mounting position, and supercooling for determining the first target subcooling degree range according to the input value of the height difference input means. By providing the degree control target range determination means,
Even if there is a large difference in height between the mounting position of the heat source side heat exchanger and the mounting position of the indoor unit, the subcooling degree of the inflow side refrigerant of the first flow rate control device is ensured within a predetermined range, and the liquid single phase state is always maintained. Therefore, the flow rate of the refrigerant supplied to the indoor unit can be accurately controlled by the first flow rate control device.

Further, in the air conditioner according to the third aspect, the pipe length input means for further inputting in accordance with the length of the connecting pipe connecting the heat source side heat exchanger and the first flow rate control device of the indoor unit. And the supercooling degree control target range determining means for determining the target range of the first supercooling degree in accordance with the input value to the pipe length input means, whereby the connecting pipe is long and the friction loss is large. Even if there is a pressure loss due to the first flow rate control device, it is possible to secure the subcooling degree of the refrigerant on the inflow side of the first flow rate device within a predetermined range and always maintain the liquid single-phase state. It can be precisely controlled by the control device.

Further, in the air conditioner according to a fourth aspect of the present invention, the heat source unit side heat exchanger is branched from the middle of the pipe connecting the first flow rate control device to the compressor through the second flow rate control device. By-pass piping reaching the suction-side low-pressure piping, detected pressure detected by second pressure detecting means provided in the discharge piping of the compressor, the heat source side heat exchanger, and the first flow rate control device A cooling-time flow rate control device control means for controlling the second flow rate control device based on a second degree of supercooling calculated from a detected temperature detected by a third temperature detection means provided in a pipe connecting By providing the, it is possible to suppress the proportion of the liquid refrigerant in the heat exchanger on the heat source unit side within a certain range, the pressure on the high pressure side of the compressor rises excessively, and the protective device operates, and the consumption of the compressor is reduced. Preventing an increase in power It can be.

In the air conditioner according to claim 5,
A bypass pipe that branches from the middle of the pipe connecting the heat source side heat exchanger and the first flow rate control device and reaches the suction side low pressure pipe of the compressor via the second flow rate control device, and the discharge of the compressor. When the detected temperature detected by the fourth temperature detecting means provided in the pipe exceeds a preset temperature, the cooling-time flow rate control device control means is controlled to increase the opening degree of the second flow rate control device. The provision of and has the effect that the discharge gas temperature of the compressor does not always rise excessively and the reliability of the compressor is improved.

In the air conditioner according to claim 6,
A pipe connecting the heat source unit side heat exchanger and the first flow rate control device and a pipe connecting the switching valve and the indoor side heat exchanger are connected via a third flow rate control device. The bypass pipe, the second pressure detecting means provided in the discharge pipe of the compressor, and the opening degree of the third flow rate control device during heating operation based on the pressure detected by the second pressure detecting means. In the heating operation, the load on the indoor side is small and the load on the heat source unit side heat exchanger is large (in the case of the air-cooling type heat exchanger, the heat exchanger is provided). Even if the intake air temperature of the compressor is high, and in the case of a water-cooled heat exchanger, the inlet water temperature of the heat exchanger is high), the discharge pressure of the compressor does not rise excessively and operation can be continued without abnormal stop. it can.

In the air conditioner according to claim 7,
By-pass pipe connecting between the pipe connecting the heat source unit side heat exchanger and the first flow rate control device and the pipe connecting the switching valve and the indoor side heat exchanger via the third flow rate control device And a fourth temperature detecting means provided in the discharge pipe of the compressor, and when the temperature detected by the fourth temperature detecting means exceeds a set temperature during the heating operation, the opening degree of the flow rate control device of the third is changed. By providing the heating-time flow rate control device that controls to increase, even in the heating operation, even if the load on the indoor unit side is small and the load on the heat source side heat exchanger is large, the discharge gas temperature of the compressor is increased. There is an effect that the reliability of the compressor is improved without increasing excessively.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a second air conditioner according to the first embodiment of the present invention.
It is a control block diagram showing the control contents of the flow control device.

FIG. 3 is a characteristic diagram showing the relationship between the opening degree of the second flow rate control device of the air conditioner according to the embodiment of the present invention and the first degree of supercooling.

FIG. 4 is a flowchart showing the control contents of the cooling-time flow rate control device control means of the air conditioner according to the first embodiment of the present invention.

FIG. 5 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a second embodiment of the present invention.

FIG. 6 is a third air conditioner according to the second embodiment of the present invention.
It is a control block diagram showing the control contents of the flow control device.

FIG. 7 is a flowchart showing the control contents of a heating time flow rate control device control means of an air conditioner according to a second embodiment of the present invention.

FIG. 8 is an overall configuration diagram centering on a refrigerant system of an air conditioner according to a third embodiment of the present invention.

FIG. 9 is an overall configuration diagram centering on a refrigerant system of a conventional air conditioner.

[Explanation of symbols]

 1 Compressor 2 4-way valve 3 Heat source side heat exchanger 5 Indoor side heat exchanger 6 First flow rate control device 11a, 11b Bypass piping 12a Second flow rate control device 12b Third flow rate control device 13a, 13b Heat Exchange unit A Heat source unit B, C, D Indoor unit 14 First pressure detecting unit 15 First temperature detecting unit 16 Second pressure detecting unit 17 Third temperature detecting unit 18 Second temperature detecting unit 19 Fourth Temperature detection means 20 Height difference input means 21 Pipe length input means 22 Supercooling degree control target range determination means 23 Cooling time flow rate control device control means 24 Heating time flow rate control device control means

Claims (7)

[Claims] 1. A heat source unit including a compressor and a heat source unit side heat exchanger, an indoor side heat exchanger, and a first unit connected to one end of the indoor side heat exchanger corresponding to the heat source unit side heat exchanger. In the refrigerant circuit in which the indoor unit equipped with the first flow rate control device is pipe-connected, the second flow rate control device is branched from the middle of the pipe connecting the heat source unit side heat exchanger and the first flow rate control device. A bypass pipe that reaches the suction side low-pressure pipe of the compressor, a pipe that connects one end of the bypass pipe on the compressor side to the second flow rate control device, and a heat source side heat exchanger. A heat exchange section for exchanging heat with a pipe connecting to the first flow rate control device; a detected pressure detected by a second pressure detecting means provided in the discharge pipe of the compressor; A second temperature detecting means provided between the heat exchange section and the first flow rate control device. And a cooling-time flow rate control device control means for controlling the second flow rate control device so that the first degree of supercooling calculated from the detected temperature detected by the second temperature control device falls within a preset target range. An air conditioner characterized by the above. 2. A height difference input means for inputting in accordance with a height difference between the heat source side heat exchanger and the indoor unit mounting position is provided, and the first subcooling is performed according to an input value of the height difference input means. The air conditioner according to claim 1, further comprising supercooling degree control target range determining means for determining a target range of the degree of cooling. 3. A pipe length input means for inputting according to the length of a connection pipe connecting the heat source side heat exchanger and the first flow rate control device of the indoor unit is provided, and the input value of the pipe length input means. The air conditioner according to claim 1, further comprising supercooling degree control target range determining means for determining a target range of the first supercooling degree according to the above. 4. A heat source unit including a compressor and a heat source unit side heat exchanger, an indoor side heat exchanger, and a first unit connected to one end of the indoor side heat exchanger corresponding to the heat source unit side heat exchanger. In the refrigerant circuit in which the indoor unit equipped with the first flow rate control device is pipe-connected, the second flow rate control device is branched from the middle of the pipe connecting the heat source unit side heat exchanger and the first flow rate control device. A bypass pipe that reaches the suction side low-pressure pipe of the compressor, a pipe that connects one end of the bypass pipe on the compressor side to the second flow rate control device, and a heat source side heat exchanger. A heat exchange section for exchanging heat with a pipe connecting to the first flow rate control device; a detected pressure detected by a second pressure detecting means provided in the discharge pipe of the compressor; The first provided on the pipe connecting the heat source unit side heat exchanger and the first flow rate control device. The cooling-time flow rate control device control means for controlling the second flow rate control device based on the second degree of supercooling calculated from the temperature detected by the temperature detection means of No. 3 is provided. Air conditioner. 5. A heat source unit having a compressor and a heat source unit side heat exchanger, an indoor side heat exchanger, and a first unit connected to one end of the indoor side heat exchanger corresponding to the heat source unit side heat exchanger. In the refrigerant circuit in which the indoor unit equipped with the first flow rate control device is pipe-connected, the second flow rate control device is branched from the middle of the pipe connecting the heat source unit side heat exchanger and the first flow rate control device. A bypass pipe that reaches the suction side low-pressure pipe of the compressor, a pipe that connects one end of the bypass pipe on the compressor side to the second flow rate control device, and a heat source side heat exchanger. The heat exchange part for exchanging heat with the pipe connecting the first flow rate control device and the temperature detected by the fourth temperature detecting means provided in the discharge pipe of the compressor are preset. If the set temperature is exceeded, the opening degree of the second flow rate control device will be increased. An air conditioner characterized by being provided with a cooling-time flow rate control device control means for performing such control. 6. A heat source unit including a compressor, a switching valve, and a heat source unit side heat exchanger, and an indoor side heat exchanger, and one end of the indoor side heat exchanger corresponding to the heat source unit side heat exchanger. First done
In a refrigerant circuit pipe-connected to an indoor unit equipped with the flow rate control device, a pipe connecting the heat source unit side heat exchanger and the first flow rate control device, the switching valve and the indoor side heat exchanger By-pass pipe connecting between the pipe connecting with and through the third flow rate control device, second pressure detecting means provided in the discharge pipe of the compressor, and during heating operation,
An air-conditioning apparatus comprising: a heating time flow rate control device control means for controlling the opening of the third flow rate control device based on the pressure detected by the second pressure detection means. 7. A heat source unit including a compressor, a switching valve, and a heat source unit side heat exchanger, and an indoor side heat exchanger, and one end of the indoor side heat exchanger corresponding to the heat source unit side heat exchanger. First done
In a refrigerant circuit pipe-connected to an indoor unit equipped with the flow rate control device, a pipe connecting the heat source unit side heat exchanger and the first flow rate control device, the switching valve and the indoor side heat exchanger By-pass pipe connecting between the pipe connecting to and via the third flow rate control device, fourth temperature detecting means provided in the discharge pipe of the compressor, and during heating operation,
An air-flow controller for heating, which controls to increase the opening of the third flow controller when the temperature detected by the fourth temperature detector exceeds a set temperature. Harmony device.