JPH0278870A - Cooling and heating device - Google Patents

Abstract

PURPOSE:To permit cooling operation and heating operation simultaneously while selecting one of them freely by an arbitrary indoor unit by a method wherein pipelines between units, which connect an outdoor unit to a plurality of indoor units, are constituted of three pieces of refrigerant pipes consisting of a high-pressure gas pipe, a low-pressure gas pipe and a liquid pipe. CONSTITUTION:When two rooms are to be cooled and one room is to be heated, cooling command is outputted from the cooling and heating switching means 21a, 21c of two sets of indoor units 5a, 5c, for example, then, respective indoor side switching valves 15a, 15c are closed and the other indoor side switching valves 16a, 16c are closed while heating command is outputted from the cooling and heating switching means 21b of one set of indoor unit 5b, then, the indoor side switching valve 15b is opened and the other indoor side switching valve 16b is closed. Simultaneously, a capacity control means 23 receives the command of two rooms cooling and one room heating from cooling and heating switching means 21a, 21b, 21c and outputs the signal of cooling > heating whereby an outdoor side switching valve 9a is opened and the other outdoor switching valves 9b, 10a, 10b are closed.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is composed of an outdoor unit and a plurality of indoor units, and can cool or heat all of the plurality of rooms at the same time, cool one room at the same time, etc. The present invention relates to a multi-room air conditioning system that heats rooms.

(B) Prior art A multi-room air conditioning system that can simultaneously cool or heat all of multiple rooms and simultaneously cool one room and heat the other rooms is disclosed in Japanese Patent Publication No. 52-24710. -24
This is disclosed in Japanese Patent Publication No. 711, Japanese Patent Publication No. 52-27459, and Publication Utility Model Publication No. 3020-1983.

(c) Problems to be solved by the invention
The device presented in Publication No. 24711 requires as many four-way switching valves and outdoor heat exchangers as there are indoor units, which complicates the piping circuit configuration, increases manufacturing costs, and requires two units for each indoor unit. Since the inter-unit piping must be drawn out from the outdoor unit, the number of inter-unit piping increases, resulting in troublesome piping work. Moreover, during air-conditioning operation that simultaneously cools one room and heats another room, the outdoor heat exchanger that corresponds to each indoor unit acts as a condenser and an evaporator, respectively, and discards heat outdoors.
The problem was that heat could not be recovered.

In addition, the above-mentioned Japanese Patent Publication No. 52-27459 and Utility Model Publication No. 5
In the device presented in Publication No. 4-3020, during air conditioning operation that cools multiple rooms and heats other rooms at the same time, the combination of rooms that can be cooled and rooms that can be heated is determined, and air conditioning operation can be performed freely in each room. This method has the disadvantage that it is not easy to use and cannot be used selectively.

It is an object of the present invention to solve the above-mentioned problems and to provide a multi-room air conditioning system that automatically performs heating and cooling operations for each indoor unit.

Means for Solving the Problems The present invention connects an outdoor heat exchanger to a refrigerant discharge pipe and a refrigerant suction pipe of a compressor via an outdoor switching valve, and connects an inter-unit pipe to the discharge pipe. A high-pressure gas pipe read directly;
Each indoor heat exchanger is configured with a low pressure gas pipe branch-connected to the suction pipe and a liquid pipe connected to a plurality of outdoor heat exchangers. It is branched and connected via an inner switching valve, and connected to the liquid pipe via a refrigerant pressure reducer, and issues a cooling command when the indoor temperature of each indoor unit exceeds the set temperature, and issues a heating command when it falls below the set temperature. Air conditioning/heating switching means for switching each indoor switching valve;
A capacity switching means is provided for switching the outdoor switching valve according to the heating and cooling load of each indoor unit.

(*) Effect When a cooling command is issued from the air conditioning/heating switching means of all indoor units, each indoor switching valve is set to the cooling state, and the outdoor switching valve is also set to the cooling state by the capacity switching means, and the compressor The discharged refrigerant flows in parallel from the discharge pipe to each outdoor heat exchanger, where it is condensed and liquefied, and then distributed to the refrigerant pressure reducer of each indoor unit via the liquid pipe, and then evaporated in each indoor heat exchanger. After being vaporized, it passes through a low-pressure gas pipe and a refrigerant suction pipe in sequence and is sucked into a compressor. In this way, all rooms can be cooled with each indoor heat exchanger acting as an evaporator.

Further, when a heating command is issued from the air conditioning/heating switching means of all the indoor units, each indoor switching valve is set to the heating state, and the outdoor switching valve is also set to the heating state by the capacity switching means, so that the compressor is not fully discharged. The refrigerant is distributed to each indoor heat exchanger through a discharge pipe and a high-pressure gas pipe, where it is condensed and liquefied, passed through each refrigerant pressure reducer, and combined in a liquid pipe, and then distributed to each outdoor heat exchanger. After being evaporated and vaporized, the refrigerant is sucked into the compressor through the refrigerant suction pipe. In this way, all rooms can be heated with each indoor heat exchanger acting as a condenser.

Furthermore, if a cooling command is issued from the air conditioning/heating switching means of any two indoor units at the same time, the respective indoor switching valves are set to the cooling state, and a heating command is issued from the air conditioning/heating switching means of one indoor unit. When the indoor switching valve is set to the heating state, the outdoor switching valve is set to the cooling state by the capacity switching means, and part of the refrigerant discharged from the compressor flows to the outdoor heat exchanger, while the remaining The refrigerant flows through the high-pressure gas pipe to the indoor heat exchanger of the heating indoor unit, and is condensed and liquefied in the indoor heat exchanger and the outdoor heat exchanger. The refrigerant condensed and liquefied in these heat exchangers is distributed to the refrigerant pressure reducer of each indoor unit via liquid pipes, then evaporated in each indoor heat exchanger, and then transferred to low pressure gas pipes and refrigerant. It passes through the suction pipe and is then sucked into the compressor. In this way, one room is heated by the indoor heat exchanger acting as a condenser, and two rooms are cooled by the other indoor heat exchanger acting as an evaporator.

(f) Embodiment The embodiment of the present invention will be explained based on the drawings.
) and a gas-liquid separator (4), (5a
) (5b) (5c) is an indoor heat exchanger (6a) (6b>
(6c) and an outdoor heat exchanger (3a).
) (3b) to the refrigerant discharge pipe (7) and refrigerant suction pipe (8) of the compressor (2) through the outdoor switching valves (9a) (10a),
(9b) (10b), while the outdoor unit (1) and indoor unit (5a) (5b) (5c
) to connect the inter-unit piping (11) to the refrigerant discharge pipe (
7), a high-pressure gas pipe (12) branch-connected to the refrigerant suction pipe (8), a low-pressure gas pipe (13) branch-connected to the refrigerant suction pipe (8), and a liquid pipe connected to the outdoor heat exchanger (3a) (3b). (14) and each indoor heat exchanger (6a) (6b) (6c)
The high-pressure gas pipe (12) and the low-pressure gas pipe (13) are equipped with indoor switching valves (15a), (16a), (15b), respectively.
16b), (15c) and (16c), and is connected to the liquid pipe (14) via refrigerant pressure reducers (17a), (17b), and (17c) such as electric expansion valves.

(18a) (18b) are auxiliary refrigerant pressure reducers such as electric expansion valves interposed in the liquid pipe (14), (19a) (19b) are outdoor blowers, (20a) (20b) (20c) are indoor blowers, (21a, 21b, and 21c) are temperature sensors (21c) that measure the indoor temperature of each indoor unit (5a), (5b, and 5c).
2a), (22b), and (22c), and when the detected temperature exceeds the set temperature, a cooling command is issued, and when it falls below the set temperature, a heating command is issued, and the respective indoor switching valves (15a) (16a) are activated.
), (15b)(16b), (15c)(16
(23) is an indoor unit); and outdoor switching valves (9a) (10a) (9b) (10b) (7
), capacity control of the variable capacity compression type 1m (2), and speed adjustment of the outdoor blower (19g) (19b).

Next, the driving operation will be explained. All indoor units (5a) (5
b) Air conditioning/heating switching means (21a) (21b) (5c)
When a cooling command is issued from 21c), each of the three indoor switching valves (15a) (15b and 15c) closes, and the other indoor switching valve (16a), (16b), and (16c) opens, and the respective indoor air Y! L machine (20a) (20b) (20
c) is driven, and the capacity switching means (23) receives a command for cooling all rooms from the respective air conditioning/heating switching means (21a) (21b) (21c) and issues a cooling signal, and one of the outdoor switching valves (9a) ) (9b) opens and the other outdoor switching valve (10a/10b) closes, and the variable capacity compressor (2) and outdoor blower (19a) (19b) are driven.

Therefore, the refrigerant discharged from the variable capacity compressor (2) sequentially flows through the discharge pipe (7), the outdoor switching valve (9, a) (9b), and the outdoor heat exchanger (3a) (3b). After being condensed and liquefied, it passes through the liquid pipe (14) to each indoor unit (5a) (
5b) (5c) (7) Refrigerant pressure reducer (17a) (17b)
(17c), where it is depressurized. After that, after being evaporated in each indoor heat exchanger (6a) (6b) (6c), the indoor switching valve (16a) < 16b) (16c)
), low pressure gas pipe (13), suction pipe (8), gas-liquid separator (
4) and is sucked into the variable capacity compressor (2).

Each indoor heat exchanger (6a
) (6b) All rooms are cooled at the same time in (6c).

During such cooling operation, for example, the indoor unit (5b) and/or
Or, when the indoor temperature in (5c) reaches the set temperature and the cooling operation stops and the cooling load decreases, the variable capacity compressor (2
), and one of the outdoor switching valves (
9a) (10b) is closed and the outdoor blower (19b) stops operating, and this outdoor heat exchanger (3b) stops functioning as a condenser and operates with compressor function power and condenser capacity commensurate with the cooling load. be done.

Conversely, when a heating command is issued from the air conditioning/heating switching means (21g>(21b>(21c)) of all the indoor units (5a) (5b) (5c), one of the indoor switching valves (15) is issued.
a) (15b) (15c) closes, the other indoor switching valve (16a) (16b) (16c) closes, and the capacity switching means (z3) switches between the respective air conditioning switching means (21a) (
21b)<21c), a heating signal is issued in response to a command for heating all rooms, one of the outdoor switching valves (9a) (9b) closes, and the other outdoor switching valve (10a) (10b) opens.

Therefore, the refrigerant discharged from the variable capacity compressor (2) sequentially passes through the discharge pipe <7>, the high pressure gas pipe (12), the indoor switching valves (15a) (15b) (15c), and the indoor heat exchanger (
6a) (6b) (6c), and after being condensed and liquefied there, the refrigerant is distributed to each refrigerant pressure reducer (17a) (17b) (17
The pressure is reduced in step c) and the liquid is merged in the pipe (14), and then evaporated in the outdoor heat exchanger (3a) (3b). ), the gas-liquid separator (4), and is sucked into the variable capacity compressor (2). In this way, each indoor heat exchanger (
6a) (6b) (6c) All rooms are heated at the same time.

During such heating operation, for example, the indoor unit (5b) and/or
Or, when the indoor temperature in (5c) reaches the set temperature and the heating operation stops and the heating load becomes small, the variable capacity compressor (2
), and one of the outdoor switching valves (
9b) (10b) is closed and the outdoor blower (19b) stops operating, and this outdoor heat exchanger (3b) stops functioning as an evaporator, and operates with compression function power and evaporator capacity commensurate with the heating load. be done.

In addition, when cooling two units and heating one room at the same time, for example, when a cooling command is issued from the air conditioning/heating switching means (21a) (21c) of any two indoor units (5a) (5c), the respective indoor units When the switching valves (15g) (15c) close, the other indoor switching valves (16a) (16c) open, and a heating command is issued from the air conditioning/heating switching means (21b) of one indoor unit (5b), one indoor switching valve (15b
) opens, the other indoor switching valve <16b) closes, and the capacity control means (23) switches to the heating/cooling switching means (21g).
(21b) Upon receiving the command for dual cooling and single room heating from (21c), it issues a cooling>heating signal, and one of the outdoor switching valves (9a
) opens and the other outdoor switching valve (9b) (10a
)(10b) closes.

Therefore, a part of the refrigerant discharged from the variable capacity compressor (2) sequentially passes through the discharge pipe (7) and the outdoor switching valve (9a) and flows only to one outdoor heat exchanger (3a), while the remaining Indoor unit 1 where refrigerant heats through high pressure gas pipe (12)
- (5b) indoor switching valve (15b), indoor heat exchanger (
6b), and is condensed and liquefied in this indoor heat exchanger (6b) and outdoor heat exchanger (3a). The refrigerant condensed and liquefied in these heat exchangers (6b) and (3a) is transferred to the liquid pipe <1
4), the refrigerant is depressurized by the refrigerant pressure reducers (17a) (17c) of the indoor units (5a) (5c), and then evaporated by the respective indoor heat exchangers (6g>(6b). The low pressure gas pipe (13) passes through the indoor switching valve (16a) (16c).
), and is suctioned into the variable capacity compressor (2) through the suction pipe (8) and the gas-liquid separator (4) in sequence. In this way, the indoor heat exchanger (6b) acting as a condenser heats the room, and the other indoor heat exchanger (6a) acting as an evaporator heats the room.
) (6c) can cool two air conditioners. - During such simultaneous cooling and heating operation, the refrigerant pressure reducer (17b) of the indoor unit (5b) is fully opened to prevent refrigerant pressure loss, but the liquid refrigerant pressure in the liquid pipe (14) does not become unbalanced. The pressure is 1 with the auxiliary pressure reducer (18a).
Tiyt is being done.

Moreover, if such simultaneous heating and cooling operation is performed in the summer when the outside air temperature is high, the outdoor blower (1
Even if 9a) is operated at high speed, the heat source cannot be sufficiently extracted from the outside air, resulting in a decrease in cooling capacity. In this operating state, the outdoor switching valve (9b) opens in response to a signal from the capacity switching means (23), and a portion of the refrigerant discharged from the discharge pipe (7) flows to the other outdoor heat exchanger (3b). After being condensed and liquefied, it passes through the auxiliary refrigerant pressure reducer (18b) and merges into the liquid pipe (14).The outdoor heat exchanger (3b), which acts as a condenser, further draws heat from the outside air and cools the room. Prevent a decline in performance. In addition, during this summer operation, for example, when the indoor temperature of the indoor unit (5c) reaches the set temperature and the cooling operation is stopped by a signal from the air conditioning/heating switching means (21c), and the cooling load becomes small, the heat source is drawn from the outside air. Since the amount may be small, for example, one of the outdoor switching valves (9a) (10a) is closed by the capacity switching means (23), and only the other outdoor heat exchanger (3b) acts as a condenser.

Next, when cooling one room and heating two rooms, this is possible by operating the auxiliary refrigerant pressure reducer (18a). For example, the heating/cooling switching means ( When a heating command is issued from 21a) (21c), the indoor switching valves (15a) (15c) open,
The other indoor switching valve (16a) (16c) is closed, and the heating/cooling switching means (21b) of one indoor unit (5b) is closed.
), one of the indoor switching valves (1
5b) closes, the other indoor switching valve (16b) opens, and the capacity control means (23>
) (21b) (21c) - In response to a command for heating two indoor cooling units, a heating signal for cooling is issued, and one outdoor switching valve (10
a) opens and the other outdoor switching valve (9a) (9b)
(10c) closes.

Therefore, the refrigerant discharged from the variable capacity compressor (2) passes through the discharge pipe (7) and the high-pressure gas pipe (12) in order and is distributed to the indoor switching valves (15a) and (15c) for indoor heat exchange. It is condensed and liquefied in vessels (6a) and (6c). Then, this liquefied refrigerant is transferred to each fully opened refrigerant pressure reducer (17a) (
17c) and flows into the liquid pipe (14), and after a part of the liquid refrigerant in this liquid pipe is depressurized by the refrigerant pressure reducer (17b), it is sent to the indoor heat exchanger (6b), and the remaining liquid refrigerant is auxiliary. After being depressurized in the refrigerant pressure reducer (18a), the refrigerant is evaporated and vaporized in the outdoor heat exchanger (38), and then passed through the suction pipe (8) and the gas-liquid separator (4) in order to be sucked into the variable capacity compressor (2). I can do it.

Indoor heat exchanger (6a) that acts as a condenser in this way
(6c) heats the two rooms, and another indoor heat exchanger (6b), which acts as an evaporator, cools the room.

If such simultaneous heating and cooling operation is performed in winter when the outside air temperature is low, the outdoor blower (19g
), even if it rotates at high speed, it cannot draw enough heat from the outside air and the heating capacity decreases. In such an operating state, a signal from the capacity switching means (23) causes the outdoor switching valve (
10b) opens, the auxiliary refrigerant pressure reducer (18b) operates, and the other outdoor heat exchanger (3b) also acts as an evaporator, thereby preventing a decrease in heating capacity. During this winter operation, for example, when the indoor temperature of the indoor unit (5c) reaches the set temperature and the heating operation is stopped by a signal from the air conditioning/heating switching means (21c) and the heating load becomes small, the heat source from the outside air is switched off. Since the amount to be pumped out may be small, the capacity switching means (23) can be used, for example, to select one of the outdoor switching valves (9a) (1).
0b) is closed and only the other outdoor heat exchanger (3b) acts as an evaporator.

In this way, each indoor unit (5a) (5b) (5c)
After comparing the indoor temperature and the set temperature, automatic heating and cooling operation is performed at will according to the cooling command and the heating command issued from the heating and cooling switching means (21a, 21b, and 21c), and the temperature is adjusted according to the size of the heating and cooling load. Accordingly, the outdoor heat exchangers (3a) and (3b) are operated as a condenser or an evaporator by the capacity switching means (23) to efficiently carry out air-conditioning and heating operations, and also act as an evaporator and a condenser during simultaneous air-conditioning and heating operations. Each working indoor heat exchanger (6a) (6b)
Heat recovery is performed in (6c), making it possible to further improve operating efficiency.

In addition, when the outdoor heat exchanger <3g) (3b), which acts as an evaporator during full-room operation, becomes frosted, one of the outdoor switching valves (9a) is switched off by a signal from the capacity switching means (23). When the outdoor heat exchanger (3a) is opened, the other outdoor switching valve (10a) is closed and a part of the high temperature discharged refrigerant is guided from the discharge pipe (7) to one outdoor heat exchanger (3a), thereby removing the outdoor heat exchanger (3a). After frosting, this one outdoor switching valve (9a)
is closed, and the other outdoor switching valve (10a) is opened to make one of the outdoor heat exchangers (3a) act as an evaporator again. At the same time, the outdoor switching valve (9b) is opened, and the outdoor switching valve (tab) is closed. The outdoor heat exchanger (3a) is closed and a part of the high temperature discharged refrigerant is guided from the discharge pipe (7) to the other outdoor heat exchanger (3b) to defrost this outdoor heat exchanger (3b). ) (3b) All room heating operation continues while defrosting alternately.

In addition, for simultaneous heating and cooling operation in which one of the outdoor heat exchangers (3a) (3b) acts as an evaporator and the other stops working,
One outdoor heat exchanger (3a) acting as an evaporator
When the outdoor heat exchanger (3a) is defrosted, one of the outdoor switching valves (9a) (10a) is switched by the signal from the capacity switching means (23) to defrost the outdoor heat exchanger (3a), and at the same time, the other outdoor switching valve ( 9b) (10b) to connect the outdoor heat exchanger (3b)
) acts as an evaporator to continue simultaneous heating and cooling operations.

In the above embodiment, three indoor units (5a) (5b)
) (5c), but even in the case of four or more indoor units with different capacities, it is sufficient to simply branch connect to the inter-unit piping (11), and connect the outdoor heat exchanger according to the number of indoor units. Alternatively, the number of outdoor heat exchangers or the number of outdoor units can be easily increased by branching and connecting the outdoor units. In addition, as the variable capacity compressor (2), a frequency conversion type, a pole number conversion type, an unloader type compressor, etc. may be used.

In addition, in the above embodiment, the switching valve (9a) (10g>,
(9b) (10b) , (15a) (16a> ,
Two-way valves were used for (15b), (16b>, (15c), and (16c), respectively, but instead of these, switching valves (9a>(1
A total of five three-way valves may be used, such as 0a) being a three-way valve and switching valves (9b) and (10b) being three-way valves.

In addition, in the above embodiment, a plurality of outdoor heat exchangers (3a>(3
b) was formed separately, but these outdoor heat exchangers (3a)
(3b) may be formed integrally.

(G) Effects of the Invention In the present invention, the inter-unit piping connecting an outdoor unit and a plurality of indoor units is composed of three types of refrigerant pipes: a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe. You can combine any number of units by simply branching them to the inter-unit piping, and you can freely select simultaneous cooling and heating operations for multiple indoor units as well as simultaneous cooling and heating operations for any indoor unit. Moreover, these simultaneous cooling operation, simultaneous heating operation, and simultaneous cooling and heating operation are automatically performed by comparing the indoor temperature of each indoor unit with the set temperature and by the cooling command and the heating command issued from the heating and cooling switching means. At the same time, the outdoor heat exchanger acts as a condenser or an evaporator according to a command issued from the capacity control means according to the size of the cooling/heating load,
Efficient heating and cooling operation can be performed.

Furthermore, during simultaneous heating and cooling operations, the indoor heat exchanger that functions as a condenser and the indoor heat exchanger that functions as an evaporator are connected in series, so that efficient operation can be achieved through heat recovery.

[Brief explanation of the drawing]

The drawing is a refrigerant circuit diagram of a heating and cooling device showing an embodiment of the present invention. (1)...Outdoor unit, (2)...Compressor,
(3a) (3b)...Outdoor heat exchanger, (5a) (5
b) (5c)...indoor unit, <6a) (6
(6c) Indoor heat exchanger, (7) Refrigerant discharge pipe, (8) Refrigerant suction pipe, (9a) (10a
), <9b) (10b)...Outdoor side switching valve, (
11>...Piping between units, (12)...High pressure gas pipe, (13)...Low pressure gas pipe, (14")...
・Liquid pipes, (15a) (16a), (15b) (1
6b), (15c) (16c) - Indoor side switching valve, (17a) (17b) (17c)... Refrigerant pressure reducer, <21a) (21b) (21c)... Air conditioning/heating switching means, (23 )...Capacity switching means.

Claims (1)

[Claims] 1. In a heating and cooling system in which an outdoor unit with a built-in compressor and an outdoor heat exchanger and multiple indoor units with built-in indoor heat exchangers are connected by inter-unit piping, the outdoor heat exchanger is connected to the refrigerant of the compressor. a high-pressure gas pipe that is branch-connected to the discharge pipe and the refrigerant suction pipe via an outdoor switching valve, and a high-pressure gas pipe that is branch-connected to the discharge pipe for inter-unit piping; and a low-pressure gas pipe that is branch-connected to the suction pipe; It is composed of a plurality of outdoor heat exchangers and connected liquid pipes, and each indoor heat exchanger is branch-connected to the high pressure gas pipe and the low pressure gas pipe via an indoor switching valve, and the liquid pipe is connected to the high pressure gas pipe and the low pressure gas pipe through an indoor switching valve. an air-conditioning/heating switching means connected to via a refrigerant pressure reducer, and issuing a cooling command when the indoor temperature of each indoor unit exceeds a set temperature, and issuing a heating command when the indoor temperature falls below the set temperature to switch the respective indoor switching valves; A heating and cooling device characterized by comprising: capacity switching means for switching an outdoor switching valve according to the heating and cooling load of each indoor unit.