JP2003343936A - Refrigeration cycle system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a current refrigeration cycle system that performance thereof is lowered by a pressure loss by the liquid head in the case of installation in a multistory building having a large height difference. <P>SOLUTION: This refrigeration cycle system is provided with a first refrigeration cycle having high-pressure piping and low-pressure piping in a direction crossing floors of the multistory building and a second refrigeration cycle having gas pipes and liquid pipes in the floor-direction of the predetermined story. This refrigeration cycle system also has a first intermediate heat exchanger provided in a piping, which is annularly connected to the high-pressure piping, to exchange the heat between the first refrigeration cycle and the second refrigeration cycle during the warm-up operation, and a second intermediate heat exchanger provided in a piping, which is annularly connected to the low-pressure piping, to exchange the heat between the first refrigeration cycle and the second refrigeration cycle during the cooling operation. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating cycle device, and more particularly to a refrigerating cycle device which does not deteriorate in performance even when installed in a high-rise building with a large height difference.

[0002]

2. Description of the Related Art Generally, in a multi-room air conditioner, which is an individually distributed air conditioner installed in a building such as a building, when it is installed in a high-rise building having a large height difference, that is, an outdoor unit is installed on a rooftop or the like. Outdoors during heating operation when installed in high places and indoor units installed on each floor, and during cooling operation when outdoor units installed in low places such as underground and indoor units installed on each floor. There has been a problem that the connection pipe connecting the unit and the indoor unit is lengthened to increase the pressure loss, and further, the pressure loss due to the liquid head due to the difference in height is also added and the performance is significantly reduced.

This will be described with reference to FIG. In FIG. 12, the refrigeration cycle apparatus includes an outdoor unit 100 installed on the roof and floors F1, F2, ..., Fn from the upper floors.
Indoor units 110a and 110 respectively installed in
b, ..., 110n and the liquid pipe 12 connecting them.
0, gas pipe 121 is mainly configured. Also,
A compressor 101 and a four-way valve 10 are provided in the outdoor unit 100.
2. The outdoor heat exchanger 103 is housed, and the indoor units 110a, 110b, ..., 110n have expansion devices 111a, 111b ,.
2a, 112b, ..., 112n are stored.

Next, the operation will be described. During heating operation, the first port 102a and the second port 102b of the four-way valve 102
Are connected, and the third port 102c and the fourth port 102d are connected. Then, the gas refrigerant discharged from the compressor 101 flows in the order of the four-way valve 102 and the gas pipe 121 to reach the indoor heat exchangers 112a, ..., 112n, and the indoor heat exchanger 112.
, 112n are condensed and liquefied. The condensed and liquefied refrigerant is reduced in pressure by the second expansion devices 111a, ..., 111n to become a low-pressure two-phase refrigerant, then flows through the liquid pipe 120 to the outdoor heat exchanger 103, and is evaporated in the outdoor heat exchanger 103. It vaporizes and returns to the compressor 101 via the four-way valve 102.

Here, in the indoor unit 110n installed on the lowest floor Fn, in the pipe from the second expansion device 111n to the outdoor heat exchanger 103, the pressure loss due to the horizontal pipe in the horizontal direction, that is, the floor direction, A pressure loss due to the liquid head occurs in the vertical direction, that is, the vertical pipe (height difference) in the floor direction, and the pressure at the outlet of the second expansion device 111n rises, resulting in a pressure difference at the inlet and outlet of the second expansion device 111n. It may decrease. Then, this second diaphragm device 11
There is a problem in that when the refrigeration cycle device is installed in a high-rise building, the refrigerant circulation amount is decreased due to the decrease in the pressure difference at the 1n inlet / outlet port.

Further, as a refrigeration cycle apparatus applicable to a high-rise building having a large height difference, for example, there is one disclosed in Japanese Patent Laid-Open No. 6-265173 as shown in FIG. In FIG. 13, a heat storage tank 200 that serves as a cold heat source and a heat storage tank 201 that serves as a hot heat source are installed in the upper part of the building, and the first heat exchangers 210a and 210b serving as condensers are provided on each floor F1, F2 ,. , And second heat exchangers 211a, 211b, ... serving as evaporators, respectively, and a plurality of indoor units 220 on each floor F1, F2 ,.
a, 220b, ... Are installed.

The heat storage tank (cold heat source) 200 and the heat exchangers 210a, 210b, ... Are connected by a cold water forward pipe 230a and a cold water return pipe 230b to form a closed circuit (first closed circuit). Pump the cold water sealed inside.
Each first heat exchanger 21 by circulating by 1
0a, 210b, ... Is supplied with cold heat.
Further, the heat storage tank (heat source) 201 and each heat exchanger 211a,
, 211b, ... Are connected to each other by a hot water forward pipe 232a and a hot water return pipe 232b to form a closed circuit (second closed circuit), and the hot water sealed inside is circulated by a pump 233 to make each second. Heat exchangers 211a, 211
Heat is supplied to b, ....

Further, each of the indoor units 220a, 220b, ... Installed on each floor F1, F2, ... Has a cooling coil and a heating coil inside, and one of the coils can be selected by a switching mechanism (not shown). Is configured so that it can be used as a cooling unit or a heating unit. The cooling coil is the refrigerant vapor pipe 240.
is connected to the corresponding heat exchangers 210a, 210b, ... Via a cooling piping system composed of a and the refrigerant liquid pipe 240b,
The heating coil includes a refrigerant vapor pipe 241a and a refrigerant liquid pipe 241.
b corresponding heat exchanger 211 via the heating piping system
a, 211b, ... Refrigerant is enclosed in the first closed circuit and the second closed circuit, respectively, and is configured to cool or heat the room by natural circulation of the refrigerant.

In this configuration, in order to perform the cooling operation,
The indoor units 220a, 220b, ... Are switched to a cooling unit and the cooling coil evaporates the refrigerant liquid to remove heat from the room to cool the internal air and perform cooling. Further, in order to perform the heating operation, the indoor units 220a, 220b, ...
Was switched to a heating unit, and the heating coil was used to condense the refrigerant vapor and heat the room to heat the inside air for heating.

Further, as a conventional refrigeration cycle apparatus, there is one disclosed in Japanese Patent Laid-Open No. 306849/1993 as shown in FIG. In FIG. 14, the heat source side cooling cycle 3
00, the heat source side heating cycle 301, and the refrigerant transfer device 3
02 bypass port of the refrigerant transfer device provided in the middle of the communication pipe that connects the discharge port and the suction port of 02, the heat source side unit 303, and the use side units 304a, 304b, 3
It is configured by a cooling auxiliary unit (not shown) located above 04c, a heating auxiliary unit 305 located below, and a utilization side refrigerant cycle 306 formed by connecting these in an annular shape. When there is a difference in height between the heat source side unit 303 and the use side units 304a, 304b, 304c, the load of the refrigerant transfer device 302 is reduced, that is, the refrigerant transfer device bypass valve and the first auxiliary heat exchanger 307 for heating.
By utilizing the natural circulation of the refrigerant during the cooling or heating operation of the use side refrigerant cycle by using, the refrigerant carrier device is downsized and the high head performance is improved.

[0011]

However, the conventional refrigeration cycle apparatus shown in FIG. 13 has two heat sources, a cold heat source and a hot heat source, and uses a heat storage tank for them, so that the apparatus becomes large in size. There was a problem of doing. In addition, since a refrigerant cycle for cooling and heating the cold heat source and the hot heat source, respectively, is required, heat exchange loss from the cooling and heating refrigerant cycle to the heat carrier medium (water) occurs,
There is a problem that power consumption increases. Furthermore, there is a problem that power consumption increases because a pump for transporting the cold heat and the hot medium is required.

Further, in the conventional refrigeration cycle apparatus shown in FIG. 14 which is separated into the heat source side refrigerant cycle and the use side refrigerant cycle, the heat source side heating cycle is installed on the lowest floor in order to utilize the natural circulation of the refrigerant. It will pass through the heating auxiliary unit located below the side unit,
As described above, there is a problem that the performance of the heat source side refrigerant cycle is deteriorated. Furthermore, since the heat source side refrigerant cycle and the use side refrigerant cycle are separated, the floor direction (vertical direction) and the floor direction (horizontal direction) of the use side refrigerant cycle are constituted by the same refrigerant circuit system, and the use side refrigerant cycle There is a problem in that the increase in the amount of the refrigerant charged affects the entire system when the refrigerant leaks and it is difficult to ensure the safety of the system.

The present invention has been made to solve the above-mentioned problems, and even when installed in a high-rise building having a large height difference, the performance is small, the size is small, the energy saving is excellent, and the freezing is highly safe. It is intended to provide a cycle device.

[0014]

A refrigeration cycle apparatus according to the present invention comprises at least one compressor and at least one compressor.
An outdoor heat exchanger of a stand, a first expansion device whose opening can be changed, a high pressure pipe installed in a floor direction of a building having a plurality of floors, and a first refrigerant cycle having a low pressure pipe, and the opening of which can be changed A second expansion device, an indoor heat exchanger, a gas pipe installed in the floor direction of each floor, and a liquid pipe, and a second refrigerant cycle installed on a predetermined floor of the building, A first intermediate heat exchanger that is provided in a pipe that is annularly connected to the pipe and that performs heat exchange between the first refrigerant cycle and the second refrigerant cycle during heating operation, and is annularly connected to the low-pressure pipe. A second intermediate heat exchanger that is provided in the pipe and that performs heat exchange between the first refrigerant cycle and the second refrigerant cycle during the cooling operation is provided.

Further, the first intermediate heat exchanger is located below the indoor heat exchanger, and the second intermediate heat exchanger is located above the indoor heat exchanger.

Furthermore, a pipe connected to the high-pressure pipe in an annular shape, a first gas-liquid separator provided on the refrigerant inflow side of the first intermediate heat exchanger, and a pipe connected to the low-pressure pipe in an annular shape, A second gas-liquid separator was provided on the refrigerant inflow side of the second intermediate heat exchanger.

The refrigeration cycle apparatus according to the present invention includes a compressor, at least one outdoor heat exchanger, a first expansion device having a variable opening degree, and high-pressure piping installed in a floor direction of a building having a plurality of floors. , And a first refrigerant cycle having low-pressure pipes, a second expansion device whose opening degree can be changed, an indoor heat exchanger, gas pipes installed in the floor direction of each floor, and liquid pipes. A second refrigerant cycle installed on a predetermined floor, which is connected to the high-pressure pipe or the low-pressure pipe through a pipe by controlling opening / closing of a valve, and heat in the first refrigerant cycle and the second refrigerant cycle. An intermediate heat exchanger for exchanging and a refrigerant liquid conveying means for forcibly circulating the refrigerant in the second refrigerant cycle are provided.

Further, the refrigerant liquid transfer means is provided in the gas pipe.

Further, the refrigerant liquid transfer means is provided in the liquid pipe.

Further, the first expansion device is arranged below the indoor heat exchanger installed on the lowest floor.

Further, the compressor and the outdoor heat exchanger are arranged in the upper layer portion.

Further, at least one outdoor heat exchanger is arranged between the compressor and the high pressure pipe, and at least one outdoor heat exchanger is arranged between the compressor and the low pressure pipe. And

Further, the compressor has a four-way valve provided on the discharge side of the compressor, the outdoor heat exchanger is connected to the four-way valve via a pipe, and further provided in a pipe connecting the four-way valve and the low pressure pipe. , Provided in the first check valve for flowing the refrigerant only from the low pressure pipe to the four-way valve and the pipe connecting the outdoor heat exchanger and the high pressure pipe, and only in the direction from the outdoor heat exchanger to the high pressure pipe A second check valve that allows the refrigerant to flow, and a pipe that connects the suction side of the first check valve and the suction side of the second check valve, are provided from the suction side of the first check valve to the first check valve. A third check valve that allows the refrigerant to flow only in the suction side of the second check valve, and a pipe that connects the discharge side of the first check valve and the discharge side of the second check valve. ,
A fourth check valve is provided which allows the refrigerant to flow only in the direction from the discharge side of the first check valve to the discharge side of the second check valve.

Further, the compressor is arranged below the indoor heat exchanger installed on the bottom floor, and the first expansion device and the outdoor heat exchanger are located below the indoor heat exchanger installed on the bottom floor. It is supposed to be placed in.

Further, a heat exchanger for recovering waste heat is provided in the first refrigerant cycle.

Further, different refrigerants are filled in the first refrigerant cycle and the second refrigerant cycle.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 is a configuration diagram showing a refrigeration cycle device according to the first embodiment. Figure 1
The middle and refrigeration cycle devices include an outdoor unit 10 arranged on the upper floor of a high-rise building 1 having a large height difference, particularly on the roof, and indoor units 30a installed on each floor F1, ..., Fn.
, 30n, branch units 50a, ..., 50n and a terminating unit 70 arranged in the underground B1 below the indoor unit 30n installed on the lowest floor.

The outdoor unit 10 is connected to the high-pressure pipe 81 and the low-pressure pipe 82 which are the first pipes provided in the floor direction, and the high-pressure pipe 81 and the low-pressure pipe 82 are provided in the terminal unit 70. It is connected through a changeable first expansion device 71 to form a heat source side refrigerant cycle. Next, of the use-side refrigerant cycles to which the indoor units 30a, ..., 30n are connected, the indoor unit 30a installed on the uppermost floor F1 will be taken as an example to describe the configuration. The indoor unit 30a is connected to a gas pipe 83a and a liquid pipe 84a, which are second pipes installed in the floor direction, and the gas pipe 83a and the liquid pipe 84a are three-way valves 51a and 52 provided in the branch unit 50a.
It is connected to the intermediate heat exchangers 53a and 54a via a to form a utilization side refrigerant cycle. Here, the heat source side refrigerant cycle (first refrigerant cycle) uses a vapor compression type refrigerant cycle using a compressor, and the use side refrigerant cycle (second refrigerant cycle) uses a natural circulation cycle without a compressor. ing.

In the outdoor unit 10, a compressor 11 for compressing a refrigerant gas, outdoor heat exchangers 12a and 12b,
13a, 13b, a blower (not shown) for blowing outside air to the outdoor heat exchangers 12a, 12b, an accumulator 14 for preventing liquid return to the compressor 11, and open / close valves 15, 16, 17, 18 , 19, 20 and pipes for connecting them are built in. Here, the compressor 1
For example, a constant speed compressor having a fixed frequency is used as 1.

On the other hand, in the branch unit 50a, intermediate heat exchangers 53a and 54a, third throttling devices 55a and 56a, which are provided in third pipes 85a and 86a which are annularly connected in the first pipe, and indoor units Three-way valves 51a and 52a for connecting 30a to either one of the intermediate heat exchangers 53a or 54a are incorporated. Here, the installation positions of the intermediate heat exchangers 53a and 54a are natural circulation operation using the indoor heat exchanger 31a as an evaporator during cooling operation, and natural circulation operation using the indoor heat exchanger 31a as a condenser during heating operation. Is installed so that That is, the intermediate heat exchanger 53a is installed above the indoor heat exchanger 31a so as to obtain a predetermined height difference, and the intermediate heat exchanger 54a is provided above the indoor heat exchanger 31a so as to obtain a predetermined height difference. Is also installed below. Here, as the intermediate heat exchangers 53a and 54a, for example, plate heat exchangers suitable for heat exchange between liquids are used. Further, the branch unit 50a includes a gas pipe 83a and a liquid pipe 84a.
Is connected to the indoor unit 30a via. Also,
The ends of the high-pressure pipe 81 and the low-pressure pipe 82 are the termination unit 7
0 is connected via a first expansion device 71 incorporated therein, and in the terminating unit 70, a pressure detector 73, a first
A temperature detector 72 is provided.

Further, in the indoor unit 30a, the indoor heat exchanger 31a, the second expansion device 32a for adjusting the flow rate of the refrigerant flowing to the indoor heat exchanger 31a, and the indoor air are forced out of the indoor heat exchanger 31a. A blower (not shown) for blowing air to the surface and piping for connecting them are built in. Further, a second temperature detector 33a is provided on the gas side of the indoor heat exchanger 30a, and a third temperature detector 34a is provided on the liquid side.
Is provided. One end of the indoor heat exchanger 31a has a second
It is connected to the liquid pipe 84a through the expansion device 32a, and the other end is connected to the gas pipe 83a. In addition, in FIG.
Although one indoor unit 30a is used, a plurality of indoor units 30a may be installed for one branch unit 50a.

Next, the operation will be described. Note that FIG.
In this case, since the frequency of the compressor 11 is fixed, the outdoor heat exchangers 12a, 12b, 13 are changed according to changes in the cooling load and the heating load.
By changing the number of a and 13b used, the cooling capacity and the heating capacity corresponding to the load are exerted.

First, the operation when the cooling load is large and there is no heating load will be described. The on-off valves 15, 17, 19, 20 in the outdoor unit 10 are closed, and the on-off valves 16,
18 is open. The third expansion device 55a in the branch unit 50a is set to an appropriate opening so that the refrigerant at the outlet of the intermediate heat exchanger 53a becomes superheated gas, and the third expansion device 56a is fully closed. The three-way valves 51a and 52a in the branch unit 50a are connected so that the refrigerant in the use-side refrigerant cycle passes through the intermediate heat exchanger 53a. The opening settings of the first expansion device 71 in the terminal unit 70 and the second expansion device 32a in the indoor unit 30a will be described later.

At this time, the high-temperature and high-pressure refrigerant vapor discharged from the compressor 11 passes through the on-off valve 16 and the outdoor heat exchanger 1
It is completely condensed and liquefied in 2a and 12b, and flows into the high-pressure pipe 81. The liquid refrigerant flowing vertically through the high pressure pipe 81 is
The pressure is reduced by the first expansion device 71 of the terminal unit 70, becomes a low-pressure two-phase refrigerant, and flows into the low-pressure pipe 82. Low pressure piping 8
The refrigerant that has risen vertically in 2 evaporates and vaporizes in the intermediate heat exchangers 53a, ..., 53n installed on each floor, passes through the on-off valve 18 in the outdoor unit 10, returns to the compressor 11 via the accumulator 14. At this time, a part of the low-pressure two-phase refrigerant passing through the low-pressure pipe 82 flows into the third pipes 85a, ..., 85n, and the refrigerant flow rate is adjusted by the third expansion device 55a, and then the intermediate heat exchanger 53a. Flow into. Intermediate heat exchanger 53
At a, the refrigerant in the heat source side refrigerant cycle evaporates and the refrigerant in the utilization side refrigerant cycle condenses. The refrigerant gas evaporated by receiving the latent heat of condensation of the use side refrigerant cycle in the intermediate heat exchanger 53a returns to the low pressure pipe 82 through the third pipe 85a.
When the cooling load is high, the low-pressure two-phase refrigerant rising in the low-pressure pipe 82 is the intermediate heat exchangers 53a, ..., 5 installed on each floor.
Since it completely evaporates and vaporizes in 3n, it passes through the open / close valve 18 without passing through the outdoor heat exchangers 13a and 13b in the outdoor unit 10, and returns to the compressor 11 via the accumulator 14.

Next, the operation of the use side refrigerant cycle will be described. In the use-side refrigerant cycle, the intermediate heat exchanger 53a operates as a condenser and the indoor heat exchanger 31a operates as an evaporator. The refrigerant liquid condensed in the intermediate heat exchanger 53a descends by gravity due to the height difference with the indoor heat exchanger 31a, passes through the liquid pipe 84a through the three-way valve 52a,
After the refrigerant flow rate is adjusted by the second expansion device 32a, the refrigerant flows into the indoor heat exchanger 31a. The refrigerant evaporated and vaporized in the indoor heat exchanger 31a passes through the gas pipe 83a, returns to the intermediate heat exchanger 53a via the three-way valve 51a, and thereby the natural refrigerant circulation of the use side refrigerant cycle is established.

Further, the cooling load is in an intermediate state (for example, 50%).
Load) and there is no heating load, the on-off valve 15,
17, 17 and 18 are closed and the on-off valves 16, 19 and 20 are opened, and the flow of the refrigerant in the outdoor unit 10 is different from that when the cooling load is large. That is, since the cooling load is in the intermediate state, the refrigerant flowing up the low-pressure pipe 82 and flowing into the outdoor unit 10 has a degree of dryness (= mass flow rate of gas refrigerant / (mass flow rate of gas refrigerant) that slightly contains unevaporated liquid. + Mass flow rate of liquid refrigerant)) is high and gas-liquid two-phase state
The non-evaporated liquid passes through the opening / closing valve 19 in the outdoor unit 10,
It evaporates in the outdoor heat exchanger 13a and returns to the compressor 11 via the on-off valve 20 and the accumulator 14. Since the open / close valve 20 is open, the refrigerant does not flow to the outdoor heat exchanger 13b having a large flow resistance, but when the flow resistance of the open / close valve 20 is large and the refrigerant also flows to the outdoor heat exchanger 13b, An on-off valve may be further provided in the middle of the pipe connecting the outdoor heat exchangers 13a and 13b.

When the cooling load is small and there is no heating load, the on-off valves 15, 17, 18, 20 are closed, the on-off valves 16, 19 are opened, and the flow of the refrigerant in the outdoor unit 10 is as described above. When the cooling load is large, it is different from the intermediate case. That is, the refrigerant that rises in the low-pressure pipe 82 and flows into the outdoor unit 10 is in a gas-liquid two-phase state with a low dryness that contains a large amount of unevaporated liquid, and the unevaporated liquid passes through the on-off valve 19 in the outdoor unit 10. After that, the outdoor heat exchanger 1
It vaporizes in both 3a and 13b, and returns to the compressor 11 via the accumulator 14.

In the heating operation when the heating load is large and there is no cooling load, the on-off valve 1 in the outdoor unit 10 is
6, 17, 18, 20 are closed, and the on-off valves 15, 19 are opened. Third expansion device 56 in the branch unit 50a
"a" is set to an appropriate opening such that the refrigerant at the outlet of the intermediate heat exchanger 54a becomes supercooled liquid, and 55a is fully closed. The three-way valves 51a and 52a in the branch unit 50a are connected so that the refrigerant in the use-side refrigerant cycle passes through the intermediate heat exchanger 54a.

At this time, the high-temperature and high-pressure refrigerant vapor discharged from the compressor 11 passes through the on-off valve 15 and the high-pressure pipe 81.
Flow into. The gas refrigerant flowing down the high-pressure pipe 81 in the vertical direction is transferred to the intermediate heat exchangers 54a, ..., 54 installed on each floor.
The first throttle device 71 of the terminal unit 70 is condensed and liquefied by n.
The pressure is reduced by and becomes a low-pressure two-phase refrigerant and flows into the low-pressure pipe 82. The refrigerant that has risen vertically in the low-pressure pipe 82 passes through the on-off valve 19 in the outdoor unit 10, and then the outdoor heat exchanger 1
3a, 13b both evaporate and vaporize, accumulator 14
And returns to the compressor 11. At this time, part of the high-pressure gas refrigerant passing through the high-pressure pipe 81 is part of the third pipe 86a, ..., 86n.
To the intermediate heat exchanger 54a after the refrigerant flow rate is adjusted by the third expansion device 56a. Intermediate heat exchanger 54
In a, the refrigerant in the heat source side refrigerant cycle is condensed and the refrigerant in the utilization side refrigerant cycle is evaporated. The refrigerant gas condensed by receiving the latent heat of vaporization of the utilization side refrigerant cycle in the intermediate heat exchanger 54a returns to the high pressure pipe 81 again through the third pipe 86a. When the heating load is high, the high-pressure gas refrigerant descending the high-pressure pipe 81 is the intermediate heat exchanger 54a installed on each floor.
, 54n is completely condensed and liquefied, and therefore becomes supercooled liquid before the first expansion device 71 of the terminal unit 70.

Next, the use side refrigerant cycle will be described. In the utilization side refrigerant cycle, the intermediate heat exchanger 54a operates as an evaporator and the indoor heat exchanger 31a operates as a condenser. The refrigerant gas evaporated in the intermediate heat exchanger 54a is the three-way valve 51a.
Through the gas pipe 83a to flow into the indoor heat exchanger 31a. The refrigerant liquid condensed and liquefied in the indoor heat exchanger 31a is
After the refrigerant flow rate is adjusted by the second expansion device 32a, it passes through the liquid pipe 84a, the three-way valve 52a, and the intermediate heat exchanger 54a.
By returning to, the natural circulation of the refrigerant in the refrigerant cycle on the utilization side is established.

The heating load is in an intermediate state (for example, 50% load)
And there is no cooling load, the on-off valves 15, 18, 20
Is closed and the on-off valves 16, 17, 19 are opened, and the flow of the refrigerant in the outdoor unit 10 is different from that when the heating load is large. That is, the outdoor heat exchanger 12
At a, the refrigerant condenses to some extent (eg, dryness 0.5),
The refrigerant flowing down the high-pressure pipe 81 is in a gas-liquid two-phase state having a high degree of dryness containing a large amount of uncondensed gas. The uncondensed gas is distributed to the branch units 50a, ..., 50n installed on each floor.
Of these, since it condenses in the intermediate heat exchanger in which the heating operation is performed, the supercooled liquid is completely condensed before the first expansion device 71 in the terminal unit 70. Then, the first diaphragm device 7
The pressure is reduced in 1 to form a low-pressure gas-liquid two-phase refrigerant, and the low-pressure pipe 82
After passing through the on-off valve 19 in the outdoor unit 10,
It is vaporized by the outdoor heat exchangers 13a and 13b and returned to the compressor 11 via the accumulator 14.

When the heating load is small and there is no cooling load, the on-off valves 15, 17, 18, 20 are closed and the on-off valve 1
When 6 and 19 are opened and the flow of the refrigerant in the outdoor unit 10 is large, the heating load is different from that in the intermediate state. That is, the outdoor heat exchangers 12a, 1
Since the refrigerant is almost condensed and liquefied in 2b, the refrigerant descending through the high-pressure pipe 81 is in a gas-liquid two-phase state with a low degree of dryness containing a small amount of uncondensed gas. Since the uncondensed gas is condensed in the intermediate heat exchangers in the branch units 50a, ..., 50n installed on each floor that perform heating operation, it is completely condensed before the first expansion device 71 in the terminal unit 70. It becomes supercooled liquid.

Next, a case where the cooling load and the heating load are mixed will be described. When both the cooling and heating loads are in the intermediate state, the on-off valves 15 and 18 are closed, and the on-off valve 1
6, 17, 19, 20 are open. At this time, the refrigerant discharged from the compressor 11 is condensed in the outdoor heat exchanger 12a to some extent (for example, a dryness of 0.5), and the uncondensed gas is heated in the intermediate heat exchangers 54a, ..., 54n. Therefore, the refrigerant is a completely condensed supercooled liquid before the first expansion device 71 in the terminal unit 70.
This supercooled liquid becomes a low-pressure gas-liquid two-phase refrigerant in the first expansion device 71 and rises in the low-pressure pipe 82. The gas-liquid two-phase refrigerant that has risen in the low-pressure pipe 82 evaporates in the intermediate heat exchangers 53a, ..., 53n in which the cooling operation is performed. The unevaporated liquid refrigerant flowing through the low-pressure pipe 82 passes through the open / close valve 19 in the outdoor unit 10, evaporates in the outdoor heat exchanger 13a, and opens / closes the open / close valve 20.
After passing through, it returns to the compressor 11 via the accumulator 14.

When both cooling and heating loads are large,
Open / close valves 16, 17, 19, 20 are closed, open / close valves 15, 1
8 is opened. Therefore, the outdoor heat exchangers 12a, 12
The operation is performed without using b, 13a, and 13b. Also, when both cooling and heating loads are small,
Open / close valves 15, 17, 18, 20 are closed, open / close valves 16, 1
9 is opened. At this time, as in the case where the cooling load is small and there is no heating load and the heating load is small and there is no cooling load, the operation in which the intermediate heat exchangers 53a, ..., 53n and 54a ,. Will be seen.

Next, a method of controlling the first diaphragm device 71 will be described. First expansion device 71 in the terminal unit 70
The opening degree of is controlled based on the detection values of the pressure detector 72 and the first temperature detector 73. That is, the saturated liquid temperature T is first calculated based on the pressure value detected by the pressure detector 72.
Convert SL1. The difference between the saturated liquid temperature TSL1 and the refrigerant liquid temperature TL1 detected by the first temperature detector 73, that is, the degree of supercooling (TSL1-TL1), approaches the preset target degree of supercooling SC1. The first diaphragm device 71 is controlled. Further, the target degree of supercooling SC1 is preferably set to about 10 to 15 ° C. so that the indoor heat exchangers 31a, ..., 31n installed on each floor can obtain sufficient heating capacity. In the present embodiment, the pressure detector 72 is used as the means for detecting the saturated liquid temperature TSL1, but the temperature detector may be a high pressure pipe 81 or a third pipe 8.
It may be installed in the middle of 6a, ..., 86n to directly detect the saturated liquid temperature. Further, the installation position of the pressure detector 72 is not limited to the position just before the first expansion device 71,
It may be installed anywhere in the high-pressure pipe from the compressor 11 to the first expansion device 71.

Next, a method of controlling the second expansion device 32a in the indoor unit 30a will be described. During the cooling operation, the detected value T1 of the second temperature detector 33a on the gas side of the indoor heat exchanger 31a and the third temperature detector 34 on the liquid side of the indoor heat exchanger 31a.
The difference (T1−T2) from the detected value T2 of a is controlled so as to approach the preset target superheat degree SH1.
The target superheat degree SH1 is determined by the temperature drop accompanying the pressure loss of the refrigerant in the indoor heat exchanger 31a and the target superheat degree at the gas side outlet of the indoor heat exchanger 31a. For example, R4
Like a non-azeotropic mixed refrigerant such as 07C, the saturated gas temperature rises as the dryness increases in a gas-liquid two-phase state under a certain pressure, and the temperature difference between the saturated liquid and the saturated gas is several degrees Celsius. For such a refrigerant, the target value should be determined in consideration of the temperature increase Tgr [deg]. As an example, the temperature drop due to the pressure loss from the inlet to the outlet of the indoor heat exchanger 31a is 2 [deg], the superheat degree of the refrigerant at the gas side outlet of the indoor heat exchanger 31a is 5 [deg], from the saturated liquid. If the temperature rise to the saturated gas is Tgr = 5 [deg], SH1 = 5-2
The target value is + 5 = 8 [deg]. Also, the target superheat degree SH
1 is preferably set to about 5 to 10 ° C. so that sufficient heat exchange is performed in the indoor heat exchanger 31a. The method of controlling the opening degree of the second expansion device 31a can be similarly applied to the other second expansion devices 31b, ..., 31n.

Further, during the heating operation, the saturated liquid temperature TSL2 is converted based on the pressure value detected by the pressure detector (not shown) installed in the use side refrigerant cycle, and the saturated liquid temperature TSL2 and the third temperature are converted. The difference from the refrigerant liquid temperature TL2 detected by the detector 34a, that is, the degree of supercooling (TSL2-T
L2) is a preset target supercooling degree SC
The second diaphragm device 32a is controlled so as to approach 2. Further, the target degree of supercooling SC2 is preferably set to about 10 to 15 ° C. so that sufficient heating capacity can be obtained in the indoor heat exchanger 31a.

The method of controlling the third expansion devices 55a and 56a in the branch unit 50a is the same as the method of controlling the opening of the second expansion device 32a. That is, the third diaphragm device 5
5a is similar to the case of the cooling operation of the second expansion device 32a,
Detection value T4 of a fourth temperature detector (not shown) installed on the gas side of the intermediate heat exchanger 53a in the third pipe 85a and detection of a sixth temperature detector (not shown) installed on the liquid side. The difference (T4-T5) from the value T5 is controlled so as to approach the preset target superheat degree SH2. In addition, the third expansion device 56a is based on the pressure value detected by the pressure detector (not shown) installed in the third pipe 86a, as in the case of the heating operation of the second expansion device 32a. Temperature TSL3
Is calculated and the difference between the saturated liquid temperature TSL3 and the refrigerant liquid temperature TL3 detected by the sixth temperature detector (not shown), that is, the degree of supercooling (TSL3-TL3), is set to a preset target excess temperature. The third expansion device 56a is controlled so as to approach the cooling degree SC3.

Although the frequency of the compressor 11 is fixed in FIG. 1, the outdoor heat exchanger is divided and used according to the cooling or heating load, but the frequency of the compressor 11 can be changed. In this case, the frequency of the compressor 11 may be changed according to the load, and it is possible to cope with this without dividing the outdoor heat exchanger. Further, by combining the control of the air flow rate of the outdoor blower, the control accuracy can be further improved, the control time can be shortened, and the control range can be widened. Further, although FIG. 1 shows an example in which the outdoor heat exchangers 13a and 13b are connected in series, they may be connected in parallel. In this case, even if the outdoor heat exchanger 13a is frosted during the heating operation, the heating operation can be continued by switching the operation to the outdoor heat exchanger 13b. Although the defrosting operation when the outdoor heat exchangers 13a and 13b are frosted during the heating operation is not described in this embodiment, a four-way valve that is a refrigerant flow path switching device is provided during the heat source side refrigerant cycle. If so, defrosting operation can be easily realized.

Further, in FIG. 1, the outdoor heat exchangers 12a, 12b and 13a, 13b in the outdoor unit 10 are divided into two, but the invention is not particularly limited to this, and it is configured to be divided into a plurality of three or more. You may. In this case,
The outdoor heat exchangers 12a and 12b and the outdoor heat exchanger 13
It is necessary to increase the number of on-off valves 15 to 20 corresponding to the number of divisions of a and 13b.

In this way, the refrigerant pipe is divided into the floor direction (vertical direction) and the floor direction (horizontal direction), and the first expansion device is arranged below the indoor heat exchanger installed on the lowest floor. By configuring the refrigerant circuit of the heat source side refrigerant cycle only in the floor direction, it is possible to prevent performance deterioration due to pressure loss in the floor direction, and refrigeration with little performance deterioration even when installed in a building with a high height difference. A cycle device can be provided. Further, since the third expansion device capable of changing the opening degree is provided in the third pipe, an appropriate heat exchange amount corresponding to the indoor cooling or heating load can be reliably obtained with the intermediate heat exchanger, and the efficiency is high. It becomes possible to drive.

Further, since the number of heat source devices is one, the system can be downsized, and the heat exchange loss is only the intermediate heat exchanger as compared with the conventional example in which the cold water or the hot water in the heat storage tank is conveyed. Electric power can be reduced, and in addition, since a pump for transporting the heat medium is not required, power consumption can be reduced accordingly. Furthermore, since the heat source side refrigerant cycle and the use side refrigerant cycle are separated and the natural refrigerant circulation that requires no power other than the indoor blower is used, the power consumption of the use side refrigerant cycle can be reduced. In addition, the refrigerant cycle is divided into a heat source side refrigerant cycle and a use side refrigerant cycle, and the floor and floor directions of the use side refrigerant cycle are configured as separate cycles, so the amount of refrigerant enclosed in the use side refrigerant cycle is reduced. Therefore, it is possible to secure the safety of the system by reducing the influence of the refrigerant leakage.

Embodiment 2. FIG. 2 is a configuration diagram of the outdoor unit according to the second embodiment. In addition, in FIG.
The same configurations and corresponding configurations are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 2, an outdoor unit 10 includes a compressor 11 capable of changing a frequency for compressing a refrigerant gas, a four-way valve 21 which is a refrigerant flow path switching device, and an outdoor heat exchanger 1.
2, a blower (not shown) for blowing the outside air to the outdoor heat exchanger 12, an accumulator 14 for preventing liquid return to the compressor 11, and a high-pressure pipe 81 connected to the outdoor unit 10. A first non-return valve for supplying a high-pressure gas or a high-pressure two-phase refrigerant, which is provided in a pipe connecting the four-way valve 21 and the low-pressure pipe 82 and allows the refrigerant to flow only from the low-pressure pipe 82 to the four-way valve 21. A valve 22, a second check valve 23 provided in a pipe connecting the outdoor heat exchanger 12 and the high-pressure pipe 81, and flowing a refrigerant only in a direction from the outdoor heat exchanger 12 to the high-pressure pipe 81; Is provided in the pipe connecting the suction side of the check valve 22 and the suction side of the second check valve 23.
The third check valve 24 that allows the refrigerant to flow only in the direction from the suction side of the first check valve 22 to the suction side of the second check valve 23, and the discharge side of the first check valve 22 and the second check valve 24. No. 4, which is provided in a pipe connecting to the discharge side of the check valve 23 and flows the refrigerant only from the discharge side of the first check valve 22 to the discharge side of the second check valve 23.
Check valve 25 of FIG.

The first port 21a of the four-way valve 21 is on the discharge side of the compressor 11, the second port 21b is a pipe to which the first check valve 22 and the fourth check valve 25 are connected, and 3 mouths 21c
Is connected to the suction side of the compressor 11 via the accumulator 14,
The fourth port 21d is connected to one end of the outdoor heat exchanger 12, respectively.

Next, the operation of the outdoor unit 10 will be described. First, the cooling operation will be described, but here, it is assumed that the frequency of the compressor 11 is changed according to the magnitude of the cooling load. First, the four-way valve 21 inside the outdoor unit 10 is set so that the first port 21a and the fourth port 21d communicate with each other and the second port 21b and the third port 21c communicate with each other. At this time, the high-temperature and high-pressure vapor refrigerant discharged from the compressor 11 is condensed and liquefied in the outdoor heat exchanger 12, and the second check valve 2
3 and flows into the high-pressure pipe 81. The liquid refrigerant flowing vertically through the high-pressure pipe 81 is decompressed by the first expansion device 71 at the lower end shown in FIG.
Inflow to 2. The refrigerant that has risen vertically in the low-pressure pipe 82 is used for the indoor units 30a, ..., 30n installed on each floor.
After completely evaporating and evaporating in the outdoor unit 10, the second check valve 22 passes through the first check valve 22 and the second port 21 of the four-way valve 21.
From b through the third port 21c into the accumulator 14,
Return to the compressor 11. At this time, a part of the low-pressure two-phase refrigerant, which is decompressed by the first expansion device 71 at the lower end and rises in the low-pressure pipe 82, flows into the intermediate heat exchanger 53a via the third expansion device 55a. In the intermediate heat exchanger 53a, the refrigerant gas evaporated by receiving the latent heat of condensation of the use side refrigerant cycle is transferred to the third pipe 85a.
Through the low pressure pipe 82 again.

Next, the heating operation will be described. Here, the frequency of the compressor 11 is also changed according to the heating load. First, the four-way valve 21 inside the outdoor unit 10 is set so that the first port 21a and the second port 21b communicate with each other and the third port 21c and the fourth port 21d communicate with each other. At this time, the high-temperature and high-pressure refrigerant compressed by the compressor 11 flows from the first port 21 a of the four-way valve 21 to the second port 21 b, the fourth check valve 25, and the high-pressure pipe 81. The refrigerant gas flowing vertically through the high-pressure pipe 81 is condensed and liquefied in the indoor units 30a, ..., 30n installed on each floor, and is decompressed by the first expansion device 71 at the lower end shown in FIG. And flows into the low pressure pipe 82. The refrigerant that has risen vertically in the low-pressure pipe 82 passes through the third check valve 24 in the outdoor unit 10 and is evaporated and vaporized in the outdoor heat exchanger 12, and the four-way valve 21 from the fourth port 21d to the third port 21.
After passing through c, it enters the accumulator 14 and returns to the compressor 11. At this time, part of the refrigerant passing through the high-pressure pipe 81 is the third part.
It flows into the intermediate heat exchanger 54a via the expansion device 56a. The refrigerant gas condensed by receiving the latent heat of vaporization of the use-side refrigerant cycle in the intermediate heat exchanger 54a joins the high-pressure pipe 81 again through the third pipe 86a.

When the cooling load and the heating load are mixed, the heat exchange amount of the outdoor heat exchanger 12 is changed to cope with the change. That is, when the cooling load is larger than the heating load,
The refrigerant gas discharged from the compressor 11 in the outdoor heat exchanger 12 is not completely condensed and liquefied, but is allowed to flow into the high-pressure pipe 81 while leaving uncondensed gas. Thereby, it is possible to supply the refrigerant gas to the indoor unit where the heating load is generated,
A cooling operation and a heating operation can be performed at the same time. Also,
When the heating load is larger than the cooling load, the refrigerant is decompressed by the first expansion device 71 at the lower end and becomes the low-pressure two-phase refrigerant and flows into the low-pressure pipe 82, but the refrigerant that has risen vertically in the low-pressure pipe 82 is Since the indoor unit where the cooling load is generated evaporates slightly, the outdoor unit 10 is kept in a dry state.
Flow into. Therefore, in the outdoor heat exchanger 12, it is only necessary to completely evaporate and evaporate the non-evaporated gas, and the heat exchange amount is reduced as compared with the case where the cooling load is not generated. As a method of controlling the heat exchange amount of the outdoor heat exchanger 12, for example, the air flow rate of a blower (not shown) for the outdoor heat exchanger 12 is changed, or the outdoor heat exchanger 12 is divided into a plurality of parts. It is conceivable to change the number of divided outdoor heat exchangers used according to the required heat exchange amount.

By doing so, the four-way valve 21 and the first
Check valve 22, second check valve 23, third check valve 24,
Even an existing cooling / heating simultaneous operation model having the fourth check valve 25 can be applied to a high-rise building without being significantly changed.

Embodiment 3. FIG. 3 is a configuration diagram of the outdoor unit according to the third embodiment. In addition, in FIG.
The same configurations and corresponding configurations are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 3, the outdoor unit 10 has an outdoor heat exchanger 26 arranged side by side in addition to the outdoor heat exchanger 12, and one end of the outdoor heat exchanger 26 has a first check valve 22 and a first check valve 22. The check valve 25 of No. 4 is connected by a pipe, and the other end is connected to the second port 21b of the four-way valve 21.

In such a configuration, since the non-evaporated liquid evaporates in the outdoor heat exchanger 26 during the cooling operation and the non-condensed gas condenses during the heating operation, the load which cannot be dealt with by changing the frequency of the compressor 11 is applied. It will be possible to deal with it. Also,
Since the outdoor heat exchangers 12 and 26 are provided with the outdoor fan 27 common to the outdoor heat exchangers 12 and 26, the outdoor unit 1 is different from the outdoor heat exchangers 12 and 26, respectively.
0 can be made small.

Fourth Embodiment FIG. 4 is a connection configuration diagram of a branch unit and an indoor unit installed on each floor according to the fourth embodiment. In addition, in FIG. 4, the same configuration as in FIG.
The same reference numerals are given to the corresponding components and the description thereof will be omitted. In FIG. 4, the gas-liquid separator 57 is installed in the third pipe 85a, and the gas-liquid separator 58 is installed in the third pipe 86a. Further, the lower part of the gas-liquid separator 57 is the third expansion device 55.
a, the upper part of the gas-liquid separator 58 is a third expansion device 56a,
Each is connected via a pipe.

Next, the operation will be described. In the cooling operation, the refrigerant liquid completely condensed in the outdoor unit 10 flows into the high-pressure pipe 81, and the liquid refrigerant flowing down the high-pressure pipe 81 in the vertical direction is decompressed by the first expansion device 71 of the terminal unit 70 to generate the low-pressure two-phase. It becomes a refrigerant and flows into the low-pressure pipe 82. The refrigerant that has risen vertically in the low-pressure pipe 82 evaporates and vaporizes in the intermediate heat exchangers 53a, ..., 53n installed on each floor, and flows into the outdoor unit 10. At this time, a part of the low-pressure two-phase refrigerant passing through the low-pressure pipe 82 flows into the gas-liquid separator 57a, and the refrigerant liquid separated from the gas-liquid is adjusted in the refrigerant flow rate by the third expansion device 55a, and then the intermediate heat is discharged. It flows into the exchanger 53a.
In the intermediate heat exchanger 53a, the refrigerant in the heat source side refrigerant cycle is evaporated and the refrigerant in the utilization side refrigerant cycle is condensed. The refrigerant gas that has evaporated by receiving the latent heat of condensation of the use-side refrigerant cycle in the intermediate heat exchanger 53a returns to the low-pressure pipe 82 again via the third pipe 85a. The gas refrigerant separated by the gas-liquid separator 57a bypasses the intermediate heat exchanger 53a and joins the third pipe 85a.

During the heating operation, the refrigerant is condensed and liquefied in the outdoor unit 10 to some extent, and the refrigerant descending through the high-pressure pipe 81 is
It becomes a gas-liquid two-phase state with high dryness including uncondensed gas.
This uncondensed gas is used in the branch unit 50 installed on each floor.
, 50n among the a, ..., 50n are condensed in the intermediate heat exchanger in which the heating operation is performed, and are completely condensed before the first expansion device 71 in the terminal unit 70. The low-pressure gas-liquid two-phase refrigerant whose pressure has been reduced by the first expansion device 71 rises in the low-pressure pipe 82 and flows into the outdoor unit 10. At this time, a part of the high-pressure two-phase refrigerant passing through the high-pressure pipe 81 flows into the gas-liquid separator 58a,
The refrigerant gas separated into gas and liquid flows into the intermediate heat exchanger 54a after the refrigerant flow rate is adjusted by the third expansion device 56a. In the intermediate heat exchanger 54a, the refrigerant in the heat source side refrigerant cycle is condensed and the refrigerant in the utilization side refrigerant cycle is evaporated. The refrigerant liquid condensed by receiving the latent heat of vaporization of the use side refrigerant cycle in the intermediate heat exchanger 54a returns to the high pressure pipe 81 again via the third pipe 86a. The liquid refrigerant separated by the gas-liquid separator 58a bypasses the intermediate heat exchanger 54a and passes through the third pipe 86.
Join a.

Thus, the third pipes 85a and 86a are
Since the gas-liquid separators 57a and 58a are provided therein, the liquid and the gas can be reliably supplied to the intermediate heat exchangers 53a and 54a, respectively, and the refrigerant noise is generated when the gas-liquid two-phase flow passes through the expansion device. It is possible to prevent the noise from being generated and reduce the jarring sound.

Embodiment 5. FIG. 5 is a connection configuration diagram of a branch unit and an indoor unit installed on each floor in the fifth embodiment. Note that in FIG. 5, the same configuration as in FIG.
The same reference numerals are given to the corresponding components and the description thereof will be omitted. In the branch unit 50a in FIG. 5, the opening / closing valve 59 is provided in the third pipe 85a annularly connected to the low pressure pipe 82, and the opening / closing valve 60 is provided in the third pipe 86a annularly connected to the high pressure pipe 81. Has been. Also, the refrigerant liquid pump 6
The refrigerant liquid transfer means mainly composed of 1 and the four-way valve 62 is connected to the liquid pipe 84a. There are no particular restrictions on the height difference between the intermediate heat exchanger and the indoor heat exchanger and the installation position of the intermediate heat exchanger.

Next, the operation will be described. During the cooling operation, the open / close valve 60 and the third expansion device 56a are closed, the open / close valve 59 is opened, and the third expansion device 55a is set to an appropriate opening degree. At this time, part of the low-pressure two-phase refrigerant passing through the low-pressure pipe 82 flows into the third pipe 85a, and the third expansion device 55a.
After the flow rate of the refrigerant is adjusted by, the refrigerant flows into the intermediate heat exchanger 53a. In the intermediate heat exchanger 53a, the refrigerant in the heat source side refrigerant cycle is evaporated and the refrigerant in the utilization side refrigerant cycle is condensed.
The refrigerant gas evaporated by receiving the latent heat of condensation of the use-side refrigerant cycle in the intermediate heat exchanger 53a passes through the on-off valve 59 and then the third
It returns to the low pressure pipe 82 again via the pipe 85a.

Next, the use side refrigerant cycle will be described. In the utilization side refrigerant cycle, the intermediate heat exchanger 53a operates as a condenser and the indoor heat exchanger 31a operates as an evaporator. The refrigerant liquid condensed in the intermediate heat exchanger 53a flows into the refrigerant liquid pump 61 via the four-way valve 62. The refrigerant discharged from the refrigerant liquid pump 61 passes through the four-way valve 62, the refrigerant flow rate is adjusted by the second expansion device 32a, and then the indoor heat exchanger 31a.
Flow into. The refrigerant evaporated and vaporized in the indoor heat exchanger 31a passes through the gas pipe 83a and returns to the intermediate heat exchanger 53a, so that the forced circulation cycle by the refrigerant liquid pump of the use side refrigerant cycle is established.

FIG. 6 shows the refrigerant flow in the cooling operation on the pressure-enthalpy diagram. In FIG. 6, a is an operation on the pressure-enthalpy diagram of the heat source side refrigerant cycle, and a is an operation on the pressure-enthalpy diagram of the utilization side refrigerant cycle. The evaporating pressure A of the use side refrigerant cycle rises as compared with the evaporating pressure B of the heat source side refrigerant cycle, but the pressure difference is smaller than the performance decrease due to the height difference when operating only in the heat source side cycle. As performance improves. In addition, the refrigerant flow in the heating operation is also shown on the pressure-enthalpy diagram similar to the cooling operation, and the condensation pressure of the usage-side refrigerant cycle is lower than the condensation pressure of the heat-source-side refrigerant cycle, but the pressure difference is It is smaller than the performance deterioration due to the height difference when operating only on the heat source side cycle, and as a result, the performance is improved.

Next, the heating operation will be described. During heating operation, the on-off valve 59 and the third expansion device 55a are closed,
The on-off valve 60 is opened and the third expansion device 56a is set to an appropriate opening. At this time, part of the high-pressure two-phase refrigerant passing through the high-pressure pipe 81 flows into the third pipe 86a, and the refrigerant flow rate is adjusted by the third expansion device 56a, and then the intermediate heat exchanger 53a.
Flow into. In the intermediate heat exchanger 53a, the refrigerant in the heat source side refrigerant cycle is condensed and the refrigerant in the utilization side refrigerant cycle is evaporated. Further, the refrigerant liquid condensed by receiving the latent heat of vaporization of the utilization side refrigerant cycle in the intermediate heat exchanger 53a returns to the high-pressure pipe 81 again through the third pipe 86a after passing through the opening / closing valve 60.

Next, the use side refrigerant cycle will be described. In the use side refrigerant cycle, the intermediate heat exchanger 53a operates as an evaporator and the indoor heat exchanger 31a operates as a condenser. The refrigerant gas evaporated in the intermediate heat exchanger 53a is supplied to the gas pipe 83
It passes through a and flows into the indoor heat exchanger 31a. The refrigerant liquid condensed and liquefied in the indoor heat exchanger 31a is supplied to the second expansion device 32a.
After the flow rate of the refrigerant is adjusted by, the liquid flows through the liquid pipe 84a, the four-way valve 62, and then the refrigerant liquid pump 61. The refrigerant liquid discharged from the refrigerant liquid pump 61 returns to the intermediate heat exchanger 53a via the four-way valve 62, whereby a forced circulation cycle using the refrigerant liquid pump 61 of the user side refrigerant cycle is established.

As described above, by providing the refrigerant liquid transfer means in the use side refrigerant cycle, only one intermediate heat exchanger is required, and further, there is no restriction on the installation of the intermediate heat exchanger. Therefore, the branching unit can be simplified and a system having a high degree of freedom in installation can be constructed.

Sixth Embodiment FIG. 7 is a connection configuration diagram of a branch unit and an indoor unit installed on each floor in the sixth embodiment. In addition, in FIG. 7, the same configuration as in FIG.
The same reference numerals are given to the corresponding components and the description thereof will be omitted. In FIG. 7, in the branch unit 50a, the opening / closing valve 59 is provided in the third pipe 85a annularly connected to the low pressure pipe 82, and the opening / closing valve 60 is provided to the third pipe 86a annularly connected in the high pressure pipe 81. It is provided. Further, a refrigerant gas transfer means mainly composed of the refrigerant gas pump 61 and the four-way valve 62 is connected to the gas pipe 83a.

Next, the operation will be described. The operation in the branch unit 50a in the cooling operation is the same as that shown in the fifth embodiment, so only the operation in the use side refrigerant cycle will be described. In the use-side refrigerant cycle, the intermediate heat exchanger 53a is the condenser and the indoor heat exchanger 3
1a operates as an evaporator. The refrigerant liquid condensed in the intermediate heat exchanger 53a flows into the indoor heat exchanger 31a after the refrigerant flow rate is adjusted by the second expansion device 32a. The refrigerant evaporated and vaporized in the indoor heat exchanger 31a passes through the gas pipe 83a, the four-way valve 62, and then flows into the refrigerant gas pump 61. The refrigerant gas discharged from the refrigerant gas pump 61 returns to the intermediate heat exchanger 53a through the gas pipe 83a after passing through the four-way valve 62, and thus the forced circulation cycle by the refrigerant gas pump of the use side refrigerant cycle is established.

Next, regarding the operation in the heating operation, the operation in the branch unit 50a is the same as that of the fifth embodiment, so only the use side refrigerant cycle will be described. In the use side refrigerant cycle, the intermediate heat exchanger 5
3a operates as an evaporator, and the indoor heat exchanger 31a operates as a condenser. The refrigerant gas evaporated in the intermediate heat exchanger 53a passes through the gas pipe 83a, passes through the four-way valve 62, and then flows into the refrigerant gas pump 61. The refrigerant gas discharged from the refrigerant gas pump 61 flows into the indoor heat exchanger 31a via the four-way valve 62. The refrigerant liquid condensed and liquefied in the indoor heat exchanger 31a is
After the refrigerant flow rate is adjusted by the second expansion device 32a, the forced circulation cycle using the refrigerant gas pump 61 of the use side refrigerant cycle is established by passing through the liquid pipe 84a and returning to the intermediate heat exchanger 53a.

FIG. 8 shows the refrigerant flow in this heating operation on the pressure-enthalpy diagram. In FIG. 8, a is an operation on the pressure-enthalpy diagram of the heat source side refrigerant cycle, and a is an operation on the pressure-enthalpy diagram of the utilization side refrigerant cycle. When the refrigerant gas pump is used, the condensing pressure A of the use side refrigerant cycle rises as compared with the condensing pressure B of the heat source side refrigerant cycle, so that it is possible to blow out at a higher temperature than in the case of only the heat source side refrigerant cycle.
Further, by using the indoor heat exchange 31a as a heat exchanger for water or brine, high temperature water such as hot water can be supplied. Further, the refrigerant flow in the cooling operation is also shown on the pressure-enthalpy diagram similar to that in the heating operation, and the evaporating pressure of the use side refrigerant cycle is lower than the evaporating pressure of the heat source side refrigerant cycle. Low temperature blowing is possible compared with the case of only. Furthermore, by using the indoor heat exchange 31a as a heat exchanger for water or brine, it is possible to supply low-temperature water such as freezing.

As described above, since the refrigerant gas transfer means is provided during the use side refrigerant cycle, only one intermediate heat exchanger is required, and further there is no restriction on the installation of the intermediate heat exchanger. The branch unit can be simplified and a system with a high degree of freedom in installation can be constructed. Further, it is possible to supply high-temperature water such as high-temperature blowout and hot water supply, and low-temperature water such as low-temperature blowout and freezing, as compared with the case of only the heat source side refrigerant cycle.

Embodiment 7. 9: is a block diagram which shows the refrigerating-cycle apparatus in Embodiment 7. In FIG. 1, the outdoor unit 10 is installed in underground B1 and the terminal unit 70 is installed in the rooftop of a building.

Even in this way, the same operation as in FIG. 1 can be performed. Moreover, since the installation unit is taken and the heavier outdoor unit 10 is installed in the underground B1, a high-rise building with a small load capacity on the rooftop floor or a high-rise building with no space on the rooftop and sufficient space underground It becomes possible to provide a refrigerating cycle device.

Eighth Embodiment 10: is a block diagram which shows the structure of the refrigerating-cycle apparatus in Embodiment 8. In the refrigerating-cycle apparatus of FIG. 1, the outdoor unit 10 is installed in underground B1 and the termination | terminus unit 70 is the rooftop of a building. When installed, the outdoor unit 10 mainly comprises only the compressor 11 and the accumulator 14, and the outdoor heat exchanger 1
2a, 12b, 13a, 13b with the first expansion device 71 in the termination unit 70 as the center, and the outdoor heat exchangers 12a, 12
b and the outdoor heat exchangers 13a and 13b are installed. Note that, in FIG. 10, the same components as those shown in FIG. 1 and the same components as those in FIG.

Next, the operation will be described. First, in the cooling operation when the cooling load is large and there is no heating load, the on-off valves 15, 17, 19, 20 in the terminal unit 70 are closed and the on-off valves 16, 18 are opened. The third expansion device 55a in the branch unit 50a is set to an appropriate opening, and the third expansion device 56a is fully closed. The three-way valves 51a and 52a in the branch unit 50a are connected so that the refrigerant in the use-side refrigerant cycle passes through the intermediate heat exchanger 53a. It should be noted that the setting of the opening degree of the first expansion device 71 in the terminal unit 70 is the same as that in the first embodiment, and thus detailed description thereof will be omitted.

The high-temperature and high-pressure refrigerant gas discharged from the compressor 11 rises in the high-pressure pipe 81 and flows into the terminal unit 70. The outdoor heat exchanger 12b in the terminal unit 70,
It is completely condensed and liquefied in 12a, is decompressed by the first expansion device 71, becomes a low-pressure two-phase refrigerant, passes through the on-off valve 18, and flows into the low-pressure pipe 82. The liquid refrigerant flowing down the low-pressure pipe 82 in the vertical direction is transferred to the intermediate heat exchangers 53a, ...
It vaporizes and vaporizes at 53n, flows into the outdoor unit 10, passes through the accumulator 14, and returns to the compressor 11. At this time, part of the low-pressure two-phase refrigerant passing through the low-pressure pipe 52 is part of the third pipe 85.
, 85n, the refrigerant flow rate is adjusted by the third expansion device 55a, and then flows into the intermediate heat exchanger 53a. In the intermediate heat exchanger 53a, the refrigerant in the heat source side refrigerant cycle is evaporated and the refrigerant in the utilization side refrigerant cycle is condensed. The refrigerant gas evaporated by receiving the latent heat of condensation of the use side refrigerant cycle in the intermediate heat exchanger 53a returns to the low pressure pipe 82 again. When the cooling load is high, the low-pressure two-phase refrigerant descending the low-pressure pipe 82 is
, 53n installed on each floor are completely evaporated and vaporized, and the compressor 11 is passed through the accumulator 14.
Return to. The operation of the use-side refrigerant cycle, the case where the cooling load is in the intermediate state and there is no heating load, or the case where the cooling load is small and there is no heating load is the same as in the first embodiment, and therefore detailed description will be omitted.

Next, the heating operation when the heating load is large and there is no cooling load will be described. In this case, the on-off valves 16, 17, 18, 20 in the terminal unit 70 are closed and the on-off valves 15, 19 are opened. In addition, the third expansion device 56a in the branch unit 50a is set to an appropriate opening, and the third expansion device 55a is fully closed. Further, the three-way valves 51a and 52a in the branch unit 50a are connected so that the refrigerant in the utilization side refrigerant cycle passes through the intermediate heat exchanger 54a. It should be noted that the setting of the opening degree of the first expansion device 71 in the terminal unit 70 is the same as that in the first embodiment, and thus detailed description thereof will be omitted.

At this time, the high temperature and high pressure refrigerant gas discharged from the compressor 11 rises in the high pressure pipe 81. When the heating load is high, the high pressure gas refrigerant rising in the high pressure pipe 81 is
, 54n installed in each floor, the high-pressure pipe 81 is raised while condensing and liquefying, and the terminating unit 7
It flows into 0. At this time, part of the high-pressure gas refrigerant passing through the high-pressure pipe 81 flows into the third pipes 86a, ..., 86n, the refrigerant flow rate is adjusted by the third expansion device 56a, and then flows into the intermediate heat exchanger 54a. . In the intermediate heat exchanger 54a, the refrigerant in the heat source side refrigerant cycle is condensed and the refrigerant in the utilization side refrigerant cycle is evaporated. The refrigerant liquid condensed by receiving the latent heat of vaporization of the use-side refrigerant cycle in the intermediate heat exchanger 54a returns to the high-pressure pipe 81 again. The liquid refrigerant flowing into the terminal unit 70 passes through the on-off valve 15 and is decompressed by the first expansion device 71 to become a low-pressure two-phase refrigerant. This low-pressure two-phase refrigerant evaporates and vaporizes in the outdoor heat exchangers 13b and 13a, and flows into the low-pressure pipe 82 via the opening / closing valve 19. The gas refrigerant flowing down the low-pressure pipe 82 in the vertical direction flows into the outdoor unit 10, returns to the compressor 11 via the accumulator 14. It should be noted that the operation in the use-side refrigerant cycle and the heating load in an intermediate state with no cooling load, and the case where the heating load is small and there is no cooling load are the same as those in the first embodiment, and detailed description thereof will be omitted. Also, when both cooling load and heating load are large,
In the case of the intermediate state, the operation when it is small is almost the same as that of the first embodiment, and therefore its explanation is omitted.

As described above, the outdoor unit 10 accommodating the compressor 11 and the accumulator 14 which are heavy objects is installed in the underground B.
Since it is installed in No. 1, it is possible to provide a refrigeration cycle apparatus suitable for a high-rise building or the like where the rooftop floor has a small withstand load.

Ninth Embodiment FIG. 11 is a configuration diagram of an outdoor unit according to the ninth embodiment, in which hot water 9 recovered by exhaust heat from a distributed power source such as a micro gas turbine or a fuel cell is collected.
Exhaust heat recovery heat exchanger 28 using 0, three-way valves 29a and 29b for switching the refrigerant flow path between the outdoor heat exchanger 12 and the exhaust heat recovery heat exchanger 28, respectively, are installed, and further three compressors are installed. 11a, 11b and 11c are provided. An inverter compressor whose frequency can be changed is used as the compressors 11a, 11b, 11c. Also,
11, the same components as those in FIG. 1 and the corresponding components are designated by the same reference numerals, and the description thereof will be omitted.

In this configuration, since a plurality of compressors are provided, the frequency control of the compressors as well as the number of the compressors can be performed, highly efficient operation is realized even for a small load, and energy saving is achieved. be able to. In addition, even if one compressor fails, the remaining compressors can continue to operate, and the failed compressor can be replaced without stopping the entire system, resulting in a highly reliable system. Can be built. Furthermore, since the exhaust heat of the distributed power sources is collected, a system with high thermal energy efficiency of the entire building can be constructed.

In FIG. 11, the method of independently controlling the heat source side refrigerant cycle and the use side refrigerant cycle is shown. However, by obtaining information on the pipe temperature and the refrigerant pressure of the indoor unit,
The control of the heat source side refrigerant cycle and the control of the utilization side refrigerant cycle may be coordinated by controlling the opening degree of the first expansion device 71. Further, the refrigerant of the heat source side refrigerant cycle and the refrigerant of the utilization side refrigerant cycle are, for example, R407 in the heat source side refrigerant cycle.
C. If the heat source side refrigerant cycle and the use side refrigerant cycle, such as R410A, are filled in the use side refrigerant cycle, it is possible to perform highly efficient operation.

[0089]

As described above, according to the present invention, it is possible to provide a refrigeration cycle apparatus in which the performance is small even when installed in a building with a high height difference.

[Brief description of drawings]

FIG. 1 is a diagram showing a refrigerant circuit configuration of a refrigeration cycle device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an outdoor unit configuration of a refrigeration cycle apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a diagram showing an outdoor unit configuration of a refrigeration cycle device according to a third embodiment of the present invention.

FIG. 4 is a diagram showing a branch unit configuration of a refrigeration cycle apparatus according to Embodiment 4 of the present invention.

FIG. 5 is a diagram showing a refrigerant circuit configuration of a refrigeration cycle device according to a fifth embodiment of the present invention.

FIG. 6 is a diagram showing operations on the pressure-enthalpy diagram of the heat source side refrigerant cycle and the use side refrigerant cycle according to the fifth embodiment of the present invention.

FIG. 7 is a diagram showing a branch unit configuration of a refrigeration cycle device according to a sixth embodiment of the present invention.

FIG. 8 is a diagram showing operations on the pressure-enthalpy diagram of the heat source side refrigerant cycle and the use side refrigerant cycle according to the sixth embodiment of the present invention.

FIG. 9 is a diagram showing a refrigerant circuit configuration of a refrigeration cycle device according to a seventh embodiment of the present invention.

FIG. 10 is a diagram showing a refrigerant circuit configuration of a refrigeration cycle device according to Embodiment 8 of the present invention.

FIG. 11 is a diagram showing an outdoor unit configuration of a refrigeration cycle apparatus according to Embodiment 9 of the present invention.

FIG. 12 is a diagram showing a refrigerant circuit configuration of a conventional refrigeration cycle apparatus.

FIG. 13 is a diagram showing a refrigerant circuit configuration of a conventional refrigeration cycle device using natural refrigerant circulation.

FIG. 14 is a diagram showing a refrigerant circuit configuration of a conventional refrigeration cycle device using a refrigerant liquid pump.

[Explanation of symbols]

1 high-rise building, 10 outdoor unit, 11 compressor, 12 outdoor heat exchanger, 13 outdoor heat exchanger, 1
4 accumulators, 15 open / close valves, 16 open / close valves,
17 on-off valves, 18 on-off valves, 19 on-off valves, 2
0 on-off valve, 21 four-way valve, 22 first check valve,
23 Second Check Valve, 24 Third Check Valve, 25
4th check valve, 26 outdoor heat exchanger, 27 blower,
28 heat exchanger for exhaust heat recovery, 29 three-way valve, 30
Indoor unit, 31 Indoor heat exchanger, 32 Second expansion device, 33 Second temperature detector, 34 Third temperature detector, 50 Branch unit, 51 Three-way valve, 52 Three-way valve, 53 Intermediate heat exchanger, 54 Intermediate heat Exchange,
55 third expansion device, 56 third expansion device, 57 gas-liquid separator, 58 gas-liquid separator, 59 on-off valve, 60
Open / close valve, 61 Refrigerant liquid pump, 62 4-way valve, 7
0 terminal unit, 71 1st expansion device, 72 pressure detector, 73 1st temperature detector, 81 high pressure piping,
82 low-pressure pipe, 83 second pipe, 84 second pipe, 85 third pipe, 86 third pipe, 90 hot water.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) F25B 5/04 F25B 5/04 B 6/04 6/04 B 7/00 7/00 D 41/04 41 / 04 C (72) Inventor Osamu Morimoto 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor ▲ Takashi Shigeo 2-3-3, Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor Nobuhiro Yoshikawa 2-3-3, Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. (72) Inventor Takashi Ikeda 2-3, Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd. In-house F-term (reference) 3L060 AA03 AA08 CC12 DD07 EE04 EE09 EE10 EE44 3L092 GA10 HA01 HA02 JA01 JA03 KA17 LA02

Claims (12)

[Claims] 1. At least one compressor, at least one
An outdoor heat exchanger of a stand, a first expansion device whose opening can be changed, a high pressure pipe installed in a floor direction of a building having a plurality of floors, and a first refrigerant cycle having a low pressure pipe, and the opening of which can be changed Refrigeration having a second expansion device, an indoor heat exchanger, a gas pipe installed in the floor direction of each floor, and a liquid pipe, and a second refrigerant cycle installed on a predetermined floor of the building A first intermediate heat exchanger, which is a cycle device, provided in a pipe annularly connected to the high-pressure pipe, and performing heat exchange between the first refrigerant cycle and the second refrigerant cycle during a heating operation. And a second intermediate heat exchanger that is provided in a pipe annularly connected to the low-pressure pipe and that performs heat exchange between the first refrigerant cycle and the second refrigerant cycle during a cooling operation. Refrigeration cycle device characterized by. 2. The first intermediate heat exchanger is located below the indoor heat exchanger, and the second intermediate heat exchanger is located above the indoor heat exchanger. The refrigeration cycle apparatus according to 1. 3. A pipe connected annularly to the high-pressure pipe, wherein a first gas-liquid separator is provided on the refrigerant inflow side of the first intermediate heat exchanger, and a pipe connected annularly to the low-pressure pipe. The refrigeration cycle apparatus according to claim 1 or 2, wherein a second gas-liquid separator is provided on the refrigerant inflow side of the second intermediate heat exchanger. 4. A first compressor having a compressor, at least one outdoor heat exchanger, a first expansion device having a variable opening degree, a high pressure pipe installed in a floor direction of a building having a plurality of floors, and a low pressure pipe. Of the refrigerant cycle, a second expansion device whose opening can be changed, an indoor heat exchanger, a gas pipe installed in the floor direction of each floor, and a liquid pipe, and are installed on a predetermined floor of the building. A refrigeration cycle apparatus including a second refrigerant cycle, which is connected to the high-pressure pipe or the low-pressure pipe via a pipe by controlling opening / closing of a valve, and includes the first refrigerant cycle and the second refrigerant cycle. A refrigeration cycle apparatus comprising: an intermediate heat exchanger for exchanging heat between and, and a refrigerant liquid transfer means for forcibly circulating the refrigerant in the second refrigerant cycle. 5. The refrigeration cycle apparatus according to claim 4, wherein the refrigerant liquid transfer means is provided in the gas pipe. 6. The refrigeration cycle apparatus according to claim 4, wherein the refrigerant liquid transfer means is provided in the liquid pipe. 7. The refrigeration cycle apparatus according to claim 1, wherein the first expansion device is arranged below an indoor heat exchanger installed on the lowest floor. 8. The refrigeration cycle apparatus according to claim 1, wherein the compressor and the outdoor heat exchanger are arranged in an upper layer portion. 9. At least one outdoor heat exchanger is arranged between the compressor and the high pressure pipe, and at least one outdoor heat exchanger is arranged between the compressor and the low pressure pipe. The refrigeration cycle apparatus according to claim 8, wherein. 10. A four-way valve provided on the discharge side of the compressor, wherein the outdoor heat exchanger is connected to the four-way valve via a pipe, and further to a pipe connecting the four-way valve and the low-pressure pipe. A first check valve that is provided to flow the refrigerant only from the low-pressure pipe in the direction of the four-way valve and a pipe that connects the outdoor heat exchanger and the high-pressure pipe to the high-pressure pipe from the outdoor heat exchanger. A second check valve that allows the refrigerant to flow only in the direction of the pipe, and a pipe that connects the suction side of the first check valve and the suction side of the second check valve, are provided in the first check valve. A third check valve that allows the refrigerant to flow only from the suction side of the check valve to the suction side of the second check valve, the discharge side of the first check valve, and the second check valve.
No. 4 check valve which is provided in a pipe connecting to the discharge side of the check valve and flows the refrigerant only in the direction from the discharge side of the first check valve to the discharge side of the second check valve. The refrigeration cycle apparatus according to claim 8, further comprising: 11. The refrigeration cycle apparatus according to claim 1, wherein a heat exchanger for recovering waste heat is provided in the first refrigerant cycle. 12. The refrigeration cycle apparatus according to claim 1, wherein the first refrigerant cycle and the second refrigerant cycle are filled with different refrigerants.