JP4909093B2 - Multi-type air conditioner - Google Patents

Description

  The present invention relates to a multi-type air conditioner, and is particularly suitable for a multi-type air conditioner in which a plurality of outdoor units are connected to a plurality of indoor units and can be operated simultaneously with cooling and heating.

  As a conventional multi-type air conditioner, there is a refrigeration apparatus described in JP-A-6-257875 (Patent Document 1). This refrigeration apparatus includes a plurality of heat source units, a plurality of utilization units, a main liquid line, a main high-pressure gas line, a main low-pressure gas line, and a piping unit.

  The heat source unit includes a compressor, a heat source side heat exchanger whose one end is switchably connected to a discharge side and a suction side of the compressor and a liquid line is connected to the other end, and a heat source side provided in the liquid line And an expansion mechanism. And the base end of the gas line branched into a high-pressure passage allowing refrigerant flow from the compressor in the discharge direction and a low-pressure passage allowing refrigerant flow in the compressor suction direction are connected to the discharge side and suction side of the compressor. Switchable connection.

  The main liquid line, the main high-pressure gas line, and the main low-pressure gas line are connected to each liquid line, each high-pressure passage, and each low-pressure passage so that each heat source unit is connected in parallel.

  The utilization unit has a utilization side heat exchanger whose one end is connected to the main liquid line, and a utilization side expansion mechanism provided between the utilization side heat exchanger and the main liquid line. The other end of the use side heat exchanger is connected to the main high-pressure gas line and the main low-pressure gas line in a switchable manner.

  The piping unit includes a check valve that allows refrigerant to flow from the heat source unit to the main high-pressure gas line, and a check valve that allows refrigerant to flow from the main low-pressure gas line to the heat source unit.

JP-A-6-257875

  In the refrigeration apparatus of Patent Document 1, a cooling / heating simultaneous operation is realized by installing a piping unit having two check valves between a plurality of heat source units and a connecting pipe to a utilization unit. However, the manufacturing cost for the piping unit is required, and a large product installation area is required. Also, during cooling operation, the low-pressure gas refrigerant that returns from the low-pressure gas pipe to the outdoor unit enters the compressor suction pipe via the check valve, gas blocking valve, and four-way valve. The performance drop due to pressure drop is inevitable.

  The object of the present invention is to reduce the manufacturing cost and the installation area, and reduce the pressure loss of the low-pressure gas refrigerant pipe returning from the low-pressure gas connection pipe to the compressor, thereby improving the performance. It is to obtain a harmony machine.

In order to achieve the above object, the present invention includes a plurality of indoor units having an indoor heat exchanger and an indoor expansion valve, a compressor, a four-way valve that can be switched between a cooling operation side and a heating operation side, outdoor heat A plurality of outdoor units having an exchanger, an outdoor expansion valve, a liquid blocking valve, a high pressure gas blocking valve, and a low pressure gas blocking valve, and arranged between the indoor unit and the outdoor unit to flow a liquid refrigerant, A liquid connection pipe branched and connected to one side of each indoor unit and the liquid blocking valve of each outdoor unit, and arranged between the indoor unit and the outdoor unit to flow high-pressure gas refrigerant, A high-pressure gas connection pipe branched and connected to the other side of each indoor unit and the high-pressure gas blocking valve of each outdoor unit, and arranged between the indoor unit and the outdoor unit to flow low-pressure gas refrigerant The other side of each indoor unit and the low pressure gas blocking valve of each outdoor unit Low-pressure gas connection pipes that are branched and connected, and at least one of the plurality of outdoor units includes only one each of the four-way valve and the outdoor heat exchanger, A pipe connecting the low-pressure gas blocking valve and the compressor suction pipe, and a valve mechanism for blocking the flow of refrigerant between the four-way valve and the high-pressure gas blocking valve; There were mixed, when a state in which the valve mechanism is closed in the stop device, among the high-pressure liquid refrigerant condensed by the indoor heat exchanger of the indoor unit, the remainder other than the liquid refrigerant to be sent to the heating operation machine The opening of the outdoor expansion valve of the stop machine is reduced and the stop of the stop machine so that the liquid refrigerant of the stop machine evaporates by the outdoor heat exchanger of the stop machine after passing through the liquid blocking valve of the stop machine. The outdoor fan that blows air to the outdoor heat exchanger is driven to Gas refrigerant evaporated by the outdoor heat exchanger of the machine is to have a configuration which is compressed by the compressor of the heating operation machine after passing through the low pressure gas gate valve of the stop device.

A more preferable specific configuration example of the present invention is as follows.
(1) When the cooling load is large and the outdoor heat exchanger is used as a condenser, the four-way valve is switched to a cooling operation side to connect the discharge side of the compressor to the outdoor heat exchanger side and the compressor The four-way valve is connected to the high pressure gas blocking valve side when the heating load is large and the outdoor heat exchanger is used as an evaporator, or when the cooling load is large and the refrigerant is not used as an evaporator and pulled to the low pressure side. To the heating operation side, connecting the discharge side of the compressor to the high-pressure gas blocking valve side, and connecting the suction side of the compressor to the outdoor heat exchanger side.
(2) The valve mechanism is configured to allow a flow from the four-way valve to the refrigerant to the high-pressure gas blocking valve and to block a flow from the high-pressure gas blocking valve to the refrigerant. Being.
(3) the plurality of outdoor units are all the four-way Ben及 beauty the outdoor heat exchanger comprising only one each, with a pipe connecting the compressor suction pipe and the low pressure gas gate valve, the four-way valve And a high-pressure gas blocking valve with a valve mechanism for blocking the flow of refrigerant.
(4) The valve mechanism is constituted by an electromagnetic valve, and the electromagnetic valve is opened when the refrigerant discharged from the compressor is used for heating the indoor unit.
(5) When the valve mechanism is constituted by a solenoid valve, and all of the plurality of indoor units are a cooling operation unit or a stop unit and the high pressure gas connection pipe is used as a low pressure gas refrigerant flow path, Opening the valve mechanism of the outdoor unit and introducing low-pressure gas refrigerant from the high-pressure gas connection pipe to the suction side of the compressor .
( 7 ) When the plurality of outdoor units are heating operation units, the defrosting of the outdoor heat exchanger of each outdoor unit is performed alternately.

  According to the multi-type air conditioner of the present invention, the manufacturing cost can be reduced and the installation area can be reduced, and the pressure loss of the low-pressure gas refrigerant pipe returning from the low-pressure gas connection pipe to the compressor can be reduced. Performance can be improved.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent. In addition, this invention includes making it more effective by combining each embodiment suitably.
(First embodiment)
A multi-type air conditioner according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a refrigeration cycle diagram of the multi-type air conditioner 100 of the present embodiment (example of use of a check valve: heating + cooling).

  The multi-type air conditioner 100 includes two outdoor units 10a and 10b, four indoor units 40a, 40b, 40c, and 40d, and a control device that controls them. This multi-type air conditioner can be operated simultaneously with cooling and heating, and the indoor operation state can simultaneously include heating operation, cooling operation, and stop. Here, the number of connected outdoor units 10 may be more than two, and the number of connected indoor units 40 may be more or less than four. Note that alphabetic suffixes attached to the reference numerals 10a to 10b, 40a to 40d, and the like may be omitted when the parts are represented generically.

  The outdoor unit 10 is formed by including only one outdoor heat exchanger 14 and four-way valve 13, as in the case of a standard air conditioner outdoor unit.

The four-way valve 13 can be switched between a cooling operation side and a heating operation side by a control device. The cooling operation side of the four-way valve 13, as shown in the broken line of the four-way valve 13a of the outdoor unit 10a of FIG. 1 (solid line of the four-way valve 13b of the outdoor unit 10b), the discharge side of the outdoor heat exchanger of the compressor 11 14 is a state where the suction side of the compressor 11 is connected to the high-pressure gas blocking valve 32 side. For example, when the outdoor unit 10 has a large cooling load and uses the outdoor heat exchanger 14 as a condenser, the four-way valve 13 is on the cooling operation side and is in the outdoor cooling operation state. Further, the heating operation side of the four-way valve 13, as shown in solid lines of the four-way valve 13a of the outdoor unit 10a of FIG. 1 (dashed line of the four-way valve 13b of the outdoor unit 10b), the discharge side of the compressor 11 is a high pressure gas It is connected to the blocking valve 32 side, and the suction side of the compressor 11 is connected to the outdoor heat exchanger 14 side. For example, in the outdoor unit 10, when the heating load is large and the outdoor heat exchanger 14 is used as an evaporator, or when the cooling load is large and it is not used as an evaporator and pulled to the low pressure side, the four-way valve 13 becomes the heating operation side. The outdoor heating operation state is set.

  The low pressure gas blocking valve 33, the low pressure gas outdoor unit piping 34, and the check valve 38 are provided in the outdoor unit 10 of the present embodiment as parts that are not included in the standard outdoor unit of the air conditioner for cooling and heating. The low pressure gas blocking valve 33 and the low pressure gas outdoor unit piping 34 connect the low pressure gas connection piping 37 and the compressor suction piping. The check valve 38 is installed in a pipe between the four-way valve 13 and the high-pressure gas blocking valve 32 (high-pressure gas connection pipe 36), and allows the refrigerant to flow from the four-way valve 13 toward the high-pressure gas connection pipe 36. It is a valve that blocks the flow. The compressor suction pipe is a pipe connecting the four-way valve 13 and the suction side of the compressor 11.

  First, the outdoor unit 10a is in the outdoor heating operation, the outdoor unit 10b is in the cooling main operation of the outdoor cooling operation, the indoor unit 40a is in the cooling operation, the indoor unit 40b is in the heating operation, and the indoor units 40c and 40d are in the stopped state. The flow of the refrigerant in the air conditioning operation will be described.

  The state of the outdoor unit 10a in the first air conditioning operation is as follows: the compressor 11a is operated, the outdoor expansion valve 15a is closed, the outdoor fan 26a is stopped, the four-way valve 13a is on the heating operation side, the outdoor expansion valve 15a is closed, and the outdoor fan 26a. Is in a stopped state.

  In this state, the high-pressure gas refrigerant compressed by the compressor 11a flows through the compressor discharge-side check valve 12a and the four-way valve 13a to the high-pressure gas blocking valve 32a side. Here, there is a check valve 38a between the four-way valve 13a and the high-pressure gas blocking valve 32a. However, since the refrigerant flows in the direction from the four-way valve 13a to the high-pressure blocking valve 32a, the check valve 38a opens and the high-pressure gas refrigerant Is sent to the high pressure gas blocking valve 32a and the high pressure gas connection pipe 36 through the check valve 38a.

  The high-pressure gas refrigerant sent to the high-pressure gas connection pipe 36 is sent to the cooling / heating switching unit 50b because the high-pressure side opening / closing mechanism 52b is open, and is sent to the heating operation indoor unit 40b through the high-pressure side opening / closing mechanism 52b. The indoor heat exchanger 41b condenses and heats the room by the indoor unit 40b, and becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant passes through the opened indoor expansion valve 42b and is sent to the liquid connection pipe 35.

  Since the outdoor expansion valve 15a is closed and the outdoor fan 26a is in a stopped state, the outdoor heat exchanger 14a does not function as an evaporator, and is merely pulled to a low pressure through the four-way valve 13a.

  On the other hand, the state of the outdoor unit 10b in the first air conditioning operation is the state where the compressor 11b is operated, the outdoor expansion valve 15b is opened, the outdoor fan 26b is operated, and the four-way valve 13b is on the cooling operation side.

In this state, the high-pressure gas refrigerant compressed by the compressor 11b passes through the compressor discharge side check valve 12b and the four-way valve 13b, flows to the outdoor heat exchanger 14b side, condenses in the outdoor heat exchanger 14b, and becomes high pressure. It becomes a liquid refrigerant. The high-pressure liquid refrigerant passes through the outdoor expansion valve 15b, the receiver 25b, and the liquid blocking valve 31b and is sent to the liquid connection pipe 35. The compressor suction pipe and the high-pressure gas stop valve 32b (high-pressure gas connection pipe 36) appear to be connected via the four-way valve 13b, but there is a check valve 38b between the four-way valve 13b and the high-pressure gas stop valve 32b. The high-pressure gas refrigerant in the high-pressure gas connection pipe 36 does not enter the compressor suction pipe and does not enter the compressor 11b or the low-pressure gas outdoor unit pipe 34b. The check valve 38 permits a flow of the four-way valve 13 to the refrigerant to the high pressure gas gate valve 32, constituting a valve mechanism for blocking the flow of refrigerant from the high pressure gas gate valve 32 to the four-way valve 13.

  The high-pressure liquid refrigerant sent from the indoor unit 40b to the liquid connection pipe 35 and the high-pressure liquid refrigerant sent from the outdoor unit 10b to the liquid connection pipe 35 merge and are sent to the cooling operation indoor unit 40a. The liquid refrigerant sent to the indoor unit 40a is throttled by the indoor expansion valve 42a, is evaporated by the indoor heat exchanger 41a, cools the room by the indoor unit 40a, becomes a low-pressure gas refrigerant, and opens the cooling / heating switching unit 50a. The high pressure side opening / closing mechanism 51a is sent to the low pressure gas connection pipe 37.

  A part of the low-pressure gas refrigerant sent to the low-pressure gas connection pipe 37 is sent to the operating outdoor unit 10a, and the rest is sent to the operating outdoor unit 10b. The low-pressure gas refrigerant sent to the outdoor unit 10a is returned to the compressor 11a through the low-pressure gas blocking valve 33a and the low-pressure gas outdoor unit piping 34a, compressed by the compressor 11a, and circulated again. On the other hand, the remaining low-pressure gas refrigerant sent to the outdoor unit 10b is returned to the compressor 11b through the low-pressure gas blocking valve 33b and the low-pressure gas outdoor unit piping 34b, compressed by the compressor 11b, and circulated again. .

  The blocking valves 31 to 33 are closed until they are installed as a multi-type air conditioner, hold the refrigerant in the refrigeration cycle of the outdoor unit 10, and are used so that they are always opened after installation. A connection part with the gas connection pipe 36 and the low-pressure gas connection pipe 37 is configured.

  Next, the second air conditioning in which the outdoor unit 10a is in the outdoor heating operation, the outdoor unit 10b is in the heating main operation, the indoor unit 40a is in the cooling operation, the indoor unit 40b is in the heating operation, and the indoor units 40c and 40d are in the stopped state. The flow of refrigerant during operation will be described.

  The state of the outdoor unit 10a in the second air conditioning operation is the state where the compressor 11a is operated, the outdoor expansion valve 15a is opened, the outdoor fan 26a is operated, and the four-way valve 13a is on the heating operation side.

  In this state, the high-pressure gas refrigerant compressed by the compressor 11a flows through the compressor discharge-side check valve 12a and the four-way valve 13a to the high-pressure gas blocking valve 32a side. Here, there is a check valve 38a between the four-way valve 13a and the high-pressure gas blocking valve 32a. However, since the refrigerant flows in the direction from the four-way valve 13a to the high-pressure blocking valve 32a, the check valve 38a opens and the high-pressure gas refrigerant Is sent to the high pressure gas blocking valve 32a and the high pressure gas connection pipe 36 through the check valve 38a.

  The high-pressure gas refrigerant sent to the high-pressure gas connection pipe 36 is sent to the heating operation indoor unit 40b through the high-pressure side opening / closing mechanism 52b opened in the cooling / heating switching unit 50b, and condensed in the indoor heat exchanger 41b. The room with 40b is heated to become a high-pressure liquid refrigerant. The high-pressure liquid refrigerant passes through the indoor expansion valve 42b and is sent to the liquid connection pipe 35. A part of the high-pressure liquid refrigerant is sent to the cooling operation indoor unit 40a, and the rest is sent to the operating outdoor unit 10a.

  The high-pressure liquid refrigerant sent to the indoor unit 40a is throttled by the indoor expansion valve 42a, evaporates in the indoor heat exchanger 41a, cools the room by the indoor unit 40a, becomes a low-pressure gas refrigerant, and opens the cooling / heating switching unit 50a. The high pressure side opening / closing mechanism 51a is sent to the low pressure gas connection pipe 37. And it is sent to the outdoor unit 10a in operation, is returned to the compressor 11a through the low-pressure gas blocking valve 33a and the low-pressure gas outdoor unit piping 34a, is compressed by the compressor 11a, and is circulated again to the refrigeration cycle.

  On the other hand, the high-pressure liquid refrigerant sent to the outdoor unit 10a passes through the liquid blocking valve 31a and the receiver 25a, is throttled by the outdoor expansion valve 15a, evaporates in the outdoor heat exchanger 14a, and exchanges heat with the outside air. It becomes a gas refrigerant, passes through the four-way valve 13a, is returned to the compressor 11a, is compressed by the compressor 11a, and is circulated again to the refrigeration cycle.

  The state of the outdoor unit 10b in the second air conditioning operation is a state in which the compressor 11b is stopped, the outdoor expansion valve 15b is closed, and the outdoor fan 26a is stopped. The four-way valve 13b may be on the heating operation side or the cooling operation side. Here, although the high-pressure gas connection pipe 36 has a high pressure, since there is a check valve 38b between the four-way valve 13b and the high-pressure gas blocking valve 32b, even if the four-way valve 13b is on the cooling operation side, The refrigerant does not accumulate in the compressor 11b and the outdoor heat exchanger 14b after the four-way valve.

  Next, the third air conditioning operation when the outdoor unit 10a is the outdoor heating operation and the outdoor unit 10b is the heating / heating-based operation of the outdoor heating operation will be described.

  In the third air conditioning operation, the high-pressure gas refrigerant compressed by the compressor 11a is sent to the high-pressure gas connection pipe 36 by the four-way valve 13a and the check valve 38a. Similarly, the high-pressure gas refrigerant compressed by the compressor 11b is sent to the high-pressure gas connection pipe 36 by the four-way valve 13b and the check valve 38b. The high-pressure liquid refrigerant condensed in the indoor heat exchanger 41 of the indoor unit 10 is distributed to the outdoor units 10a and 10b, evaporated in the outdoor heat exchangers 14a and 14b, compressed by the compressors 11a and 11b, and recirculated. To do.

  Next, the fourth air conditioning operation in the case where the outdoor unit 10a is in the outdoor cooling operation, the outdoor unit 10b is in the cooling operation, or the outdoor unit 10a is in the outdoor cooling operation, and the outdoor unit 10b is in the outdoor cooling operation. The fifth air conditioning operation in this case will be described.

  In the fourth and fifth air conditioning operations, the check valve 38a is provided between the four-way valve 13a and the high-pressure gas blocking valve 32a, and the check valve 38b is provided between the four-way valve 13b and the high-pressure gas blocking valve 32b. Therefore, the high-pressure gas refrigerant does not flow into the compressors 11a and 11b from the high-pressure gas connection pipe 36, and a predetermined air conditioning operation is possible. However, the low-pressure gas refrigerant from the low-pressure gas connection pipe 37 passes through the low-pressure gas blocking valve 33a and the low-pressure gas outdoor unit pipe 34a, is compressed by the compressor 11a, and circulates again. Further, when the outdoor unit 10b in the fifth air conditioning operation is in the outdoor cooling operation, the low-pressure gas refrigerant is distributed to the outdoor unit 10b in addition to the outdoor unit 10a, and the low-pressure gas refrigerant sent to the outdoor unit 10b is low-pressure gas blocking It passes through the valve 33b and the low-pressure gas outdoor unit piping 34b, is compressed by the compressor 11b, and circulates again.

As described above, according to the present embodiment, the check valve 38 causes the high-pressure gas refrigerant to be sent from the four-way valve 13 to the high-pressure gas connection pipe 36 in the case of an outdoor unit during heating operation, and during cooling operation or when stopped. In the case of the inside outdoor unit, the high-pressure gas refrigerant in the high-pressure gas connection pipe 36 can be prevented from entering the compressor 11 and the outdoor heat exchanger 14 in the outdoor unit. In addition, since the low-pressure gas refrigerant pipe returning from the low-pressure gas connection pipe 37 to the compressor 11 is composed of the low-pressure gas outdoor unit pipe 34 directly connected from the low-pressure gas blocking valve 33 to the compressor suction pipe, the pressure in the four-way valve The pressure loss can be reduced as compared with the conventional example causing the loss, and the performance can be improved by that amount. Since the check valve 38 and the low-pressure gas outdoor unit pipe 34 are built in the outdoor unit 10, the manufacturing cost can be reduced and the installation area can be reduced as compared with the conventional example including the pipe unit.
(Second Embodiment)
Next, a multi-type air conditioner according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a refrigeration cycle system diagram of the multi-type air conditioner according to the second embodiment of the present invention (example of use of solenoid valve: heating + cooling). The second embodiment is different from the first embodiment in the points described below, and the other points are basically the same as those in the first embodiment, and thus redundant description is omitted.

  In the second embodiment, the check valve 38 between the four-way valve 13 and the high-pressure blocking valve 32 in the first embodiment is replaced with an electromagnetic valve 39. The electromagnetic valve 39 is controlled by the control device so as to have a function equivalent to that of the check valve 38. That is, in the case of the outdoor unit 10 during the outdoor heating operation, the electromagnetic valve 39 is opened and the refrigerant is controlled to be sent from the four-way valve 13 to the high-pressure gas connection pipe 36. In the case of the outdoor unit 10 during outdoor cooling operation or stopped, the solenoid valve 39 is closed to prevent the refrigerant in the high pressure gas connection pipe 36 from entering the compressor 11 and the outdoor heat exchanger 14 in the outdoor unit. Controlled.

  First, the case where the outdoor unit 10a is the outdoor heating operation and the outdoor unit 10b is the cooling main operation of the outdoor cooling operation will be described. Regarding the outdoor unit 10a, the compressor 11a is operated, the outdoor expansion valve 15a is closed, the outdoor fan 26a is stopped, the four-way valve 13a is on the heating operation side, and an electromagnetic valve 39a is provided between the four-way valve 13a and the high-pressure gas blocking valve 32a. There is. The high-pressure gas refrigerant compressed by the compressor 11a passes through the four-way valve 13a and reaches the electromagnetic valve 39a. The electromagnetic valve 39a is opened to allow the refrigerant to flow through the high-pressure blocking valve 32a. Regarding the outdoor unit 10b, the compressor 11b is operated, the outdoor expansion valve 15b is opened, the outdoor fan 26b is operated, the four-way valve 13b is on the cooling operation side, and an electromagnetic valve 39b is provided between the four-way valve 13b and the high-pressure gas blocking valve 32b. There is. When the electromagnetic valve 39b is opened, the high-pressure gas refrigerant enters the suction side of the compressor 11b that is performing the cooling operation through the four-way valve 13b, and the compressor 11b is overloaded, so that the electromagnetic valve 39b is closed.

  Next, the case where the outdoor unit 10a is in the outdoor heating operation and the outdoor unit 10b is in the stopped heating / heating main operation will be described. In the outdoor unit 10a, the electromagnetic valve 39a is opened in order to allow the refrigerant to flow through the high-pressure blocking valve 32a. In the outdoor unit 10b, the electromagnetic valve 39b is closed to prevent the high-pressure gas refrigerant from flowing into the outdoor unit 10b.

  Next, the case where the outdoor unit 10a is in the outdoor heating operation and the outdoor unit 10b is in the outdoor heating operation will be described. In both the outdoor unit 10a and the outdoor unit 10b, the electromagnetic valves 39a and 39b are opened to allow the refrigerant to flow through the high-pressure blocking valves 32a and 32b.

Next, a case where the outdoor unit 10a is in the outdoor cooling operation and the outdoor unit 10b is in the cooling operation, or a case where the outdoor unit 10a is in the outdoor cooling operation and the outdoor unit 10b is in the outdoor cooling operation will be described. In order to prevent the refrigerant in the high-pressure gas connection pipe 36 from flowing into the outdoor units 10a and 10b, the electromagnetic valves 39a and 39b are closed.
(Third embodiment)
Next, a multi-type air conditioner according to a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a refrigeration cycle system diagram of a multi-type air conditioner according to a third embodiment of the present invention (example of use of solenoid valves: all-room cooling). The third embodiment is different from the second embodiment in the following points, and the other points are basically the same as those in the second embodiment, and thus redundant description is omitted.

  In the third embodiment, the check valve between the four-way valve 13 and the high-pressure gas blocking valve 32 is replaced with the electromagnetic valve 39 as in the second embodiment. However, the electromagnetic valve is limited to the outdoor cooling operation. By opening the valve 39 and opening the high-pressure side opening / closing mechanism 51 of the cooling / heating switching unit, the low-pressure gas is distributed to each of the low-pressure gas connection pipe 37 and the high-pressure gas connection pipe 36 to reduce the connection pipe pressure loss and improve the performance. It is an example.

  Both the outdoor units 10a and 10b will be described in the cooling operation of the outdoor cooling operation, the indoor units 40a and 40b will be in the cooling operation, and the refrigerant flow when the indoor units 40c and 40d are stopped will be described.

  Regarding the outdoor unit 10a, the high-pressure gas refrigerant compressed by the compressor 11a passes through the four-way valve 13a, condenses in the outdoor heat exchanger 14a, and becomes high-pressure liquid refrigerant. The high-pressure liquid refrigerant passes through the outdoor expansion valve 15a, the receiver 25a, and the liquid blocking valve 31a and is sent to the liquid connection pipe 35. Similarly, in the outdoor unit 10b, the high-pressure liquid refrigerant is sent to the liquid connection pipe 35.

The high-pressure liquid refrigerant is sent to the indoor units 40a and 40b, throttled by the indoor expansion valves 42a and 42b, evaporated by the indoor heat exchangers 41a and 41b, becomes low-pressure gas refrigerant, and is sent to the cooling / heating switching units 50a and 50b. . Normally, during the cooling operation, the low pressure side opening / closing mechanisms 51a, 51b in the cooling / heating switching units 50a, 50b are opened and the high pressure side opening / closing mechanisms 52a, 52b are closed, but here the high pressure side opening / closing mechanisms 52a, 52b are also opened. Is done. May be used an electromagnetic valve and the check valve in parallel as the opening and closing mechanism, thereby the function of the check valve used in parallel without opening the electromagnetic valve, the pressure in the high pressure gas connection pipe 36 decreases In the case, the refrigerant can flow out. The low-pressure gas refrigerant sent to the cooling / heating switching units 50a, 50b is divided into the low-pressure gas connection pipe 37 and the high-pressure gas connection pipe 36 by opening both the low-pressure side opening / closing mechanisms 51a, 51b and the high-pressure side opening / closing mechanisms 52a, 52b. It is possible to reduce the pressure loss of the gas connection piping.

  The low-pressure gas refrigerant sent to the low-pressure gas connection pipe 37 is sent to the compressors 11a and 11b through the low-pressure gas blocking valves 33a and 33b and the low-pressure gas outdoor equipment pipes 34a and 34b of the outdoor units 10a and 10b. Circulate. The low-pressure gas refrigerant sent to the high-pressure gas connection pipe 36 passes through the high-pressure gas blocking valves 32a and 32b, the electromagnetic valves 39a and 39b, and the four-way valves 13a and 13b of the outdoor units 10a and 10b. It is sent to 11b and recirculated. Here, the direction in which the refrigerant flows through the electromagnetic valves 39a and 39b is opposite to that during outdoor heating operation, and a bidirectional electromagnetic valve may be used. Further, the check valve and the solenoid valve may be arranged in parallel so that the check valve flows in the outdoor heating operation and the solenoid valve opens and closes in the cooling operation. A solenoid valve may be used.

Even when the outdoor unit 10a is in the outdoor cooling operation and the outdoor unit 10b is stopped, the refrigerant circulates similarly in the outdoor unit 10a. Regarding the outdoor unit 10b, since the compressor 11b is stopped, the refrigerant does not flow, and the electromagnetic valve 39b may be open or closed.
(Fourth embodiment)
Next, a multi-type air conditioner according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a refrigeration cycle system diagram of a multi-type air conditioner according to a fourth embodiment of the present invention (use example of a heat exchanger for a stop outdoor unit). The fourth embodiment is different from the second and third embodiments in the following points, and the other points are basically the same as those of the second and third embodiments, and thus overlap. Description is omitted.

  In the fourth embodiment, as in the second and third embodiments, the check valve between the four-way valve 13 and the high-pressure gas blocking valve 32 is replaced with a solenoid valve. When the outdoor heating operation and the stop are mixed, by controlling the outdoor expansion valve 15b and the outdoor fan 26b of the stop outdoor unit 10b, the outdoor heat exchanger 14b is utilized as an evaporator, and the evaporator area is increased. This is an example of improving the performance.

  The refrigerant flow when the outdoor unit 10a is the outdoor heating operation, the outdoor unit 10b is the heating operation stopped, the indoor units 40a and 40b is the heating operation, and the indoor units 40c and 40d are stopped will be described.

  Regarding the outdoor unit 10a, the compressor 11a is operated, the outdoor expansion valve 15a is opened, the outdoor fan 26a is operated, the four-way valve 13a is on the heating operation side, and the electromagnetic valve 39a is opened. The high-pressure gas refrigerant compressed by the compressor 11a passes through the four-way valve 13a, the electromagnetic valve 39a, the high-pressure gas blocking valve 32a, and the high-pressure gas connection pipe 36 and is sent to the indoor units 40a and 40b. Here, since the solenoid valve 39b of the stop outdoor unit 10b is closed, the high-pressure gas refrigerant does not enter the outdoor unit 10b. The high-pressure liquid refrigerant condensed in the indoor units 40a and 40b passes through the cooling / heating switching units 50a and 50b and is sent to the liquid connection pipe 35. Here, since the outdoor heat exchanger 14b of the stop outdoor unit 10b is also used as an evaporator, a part of the high-pressure liquid refrigerant is sent to the outdoor unit 10a and the rest is sent to the outdoor unit 10b.

  First, the high-pressure liquid refrigerant sent to the outdoor unit 10a passes through the liquid blocking valve 31a and the receiver 25a, is throttled by the outdoor expansion valve 15a, evaporates in the outdoor heat exchanger 14a, and exchanges heat with the outside air. Then, it passes through the four-way valve 13a, is compressed again by the compressor 11a, and circulates in the refrigeration cycle.

On the other hand, the remaining high-pressure liquid refrigerant sent to the outdoor unit 10b passes through the liquid blocking valve 31b and the receiver 25b, is throttled by the outdoor expansion valve 15b, is evaporated by the outdoor heat exchanger 14b, and the outdoor fan 26b is driven. As a result, heat is exchanged with the outside air to form a low-pressure gas refrigerant, which passes through the four-way valve 13b and reaches the suction side of the compressor 11b. Here, since the compressor 11b is stopped, the low-pressure gas refrigerant is sent to the low-pressure gas outdoor unit piping 34b, the low-pressure gas blocking valve 33b, and the low-pressure gas connection piping 37. Then, it passes through the low-pressure gas blocking valve 33a and the low-pressure gas outdoor unit piping 34a of the outdoor unit 10a during operation, is compressed again by the compressor 11a, and circulates in the refrigeration cycle.
(Fifth embodiment)
Next, the multi type air conditioner of 5th Embodiment of this invention is demonstrated using FIG. FIG. 5 is a refrigeration cycle diagram (example of individual defrosting of an outdoor heat exchanger) of a multi-type air conditioner according to a fifth embodiment of the present invention. The fifth embodiment is different from the second embodiment in the following points, and the other points are basically the same as those in the second embodiment, and thus redundant description is omitted.

  In the fifth embodiment, when the outdoor heat exchangers 14 of the plurality of outdoor units 10 are frosted and the evaporation performance is reduced, the outdoor units 10 are not defrosted all at once in the reverse cycle. It is an example which defrosts individually. Since any one of the outdoor units 10 continues the outdoor heating operation, the heating operation of the indoor unit 40 is not stopped, and there is no discomfort due to the hot air stop.

  The refrigerant flow when the outdoor unit 10a is the outdoor heating operation, the outdoor unit 10b is the outdoor cooling operation corresponding to defrosting, the indoor units 40a and 40b are the heating operation, and the indoor units 40c and 40d are stopped will be described.

  Regarding the outdoor unit 10a, the compressor 11a is operated, the outdoor expansion valve 15a is opened, the outdoor fan 26a is operated, the four-way valve 13a is on the heating operation side, and the electromagnetic valve 39a is opened. The high-pressure gas refrigerant compressed by the compressor 11a passes through the four-way valve 13a, the electromagnetic valve 39a, the high-pressure gas blocking valve 32a, and the high-pressure gas connection pipe 36, is used for heating in the indoor units 40a and 40b, and then condensed. The liquid refrigerant is sent to the liquid connection pipe 35 through the cooling / heating switching units 50a and 50b. This is continued even if the outdoor unit 10b is defrosting.

  Regarding the outdoor unit 10b, the compressor 11a is operated, the outdoor expansion valve 15b is opened, the outdoor fan 26b is stopped, the four-way valve 13b is on the cooling operation side, and the electromagnetic valve 39b is closed. The high-pressure gas refrigerant compressed by the compressor 11b passes through the four-way valve 13b and is used as a heat source for melting frost adhering to the heat exchanger surface of the outdoor heat exchanger 14b, condensing into high-pressure liquid refrigerant, and the outdoor expansion valve 15b. , And sent to the liquid connection pipe 35 through the receiver 25b.

  The high-pressure liquid refrigerant sent from the cooling / heating switching units 50a and 50b and the outdoor unit 10b is sent to the outdoor unit 10a during the outdoor heating operation, passes through the receiver 25a and the outdoor expansion valve 15a, and is exchanged with the outdoor air in the outdoor heat exchanger 14a. It exchanges heat and becomes a low-pressure gas refrigerant, and a part is compressed by the compressor 11a and recirculated. The remaining low-pressure gas refrigerant passes through the low-pressure gas outdoor unit piping 34a, the low-pressure gas blocking valve 33a, the low-pressure gas connection piping 37, the low-pressure gas blocking valve 33b, and the low-pressure gas outdoor unit piping 34b, and is compressed and recirculated by the compressor 11b. .

The outdoor unit side is not different from the simultaneous cooling and heating operation because only the outdoor heating operation and the outdoor cooling operation are mixed. However, since the indoor unit side does not have the cooling operation indoor unit, the low pressure gas connection pipe 37 is different from the simultaneous cooling and heating operation. There is no supply of low-pressure gas refrigerant from the indoor unit to the outdoor cooling operation unit via However, since the plurality of outdoor unit compressor suction pipes 34a and 34b are connected via the low pressure gas connection pipe 37, the low pressure gas refrigerant of the outdoor heating operation unit is distributed to the operating compressors 11a and 11b. The For this reason, the suction pressure is lowered and the high pressure ratio operation is not performed, and the compressors 11a and 11b can be operated within an appropriate range.
(Sixth embodiment)
Next, a multi-type air conditioner according to a sixth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a refrigeration cycle diagram of a multi-type air conditioner according to a sixth embodiment of the present invention (combination example with a cooling / heating simultaneous multi-dedicated outdoor unit). The sixth embodiment is different from the first embodiment in the points described below, and the other points are basically the same as those in the first embodiment, and therefore, redundant description is omitted.

  In the sixth embodiment, one unit is an ordinary outdoor unit 10a for simultaneous cooling and heating, and one unit is an example in which the outdoor unit 10b of the present invention is combined. This simultaneous cooling and heating outdoor unit 10a includes a plurality of four-way valves 13a and 16a, outdoor unit heat exchangers 14a and 17a, outdoor expansion valves 15a and 18a, and outdoor fans 26a and 27a. In the sixth embodiment, in order to cope with the case where the difference in indoor cooling / heating load is small, only one unit uses a simultaneous cooling / heating outdoor unit and a small heat exchanger formed by dividing the outdoor heat exchanger. Thus, power saving can be achieved. In this case, the outdoor unit 10a of the present invention may be moved when the normal outdoor unit 10a for cooling and heating is used as a master unit and the evaporation capability and the condensation capability of the entire outdoor unit are insufficient.

It is a refrigerating cycle system diagram by a 1st embodiment of the present invention. It is a refrigeration cycle system diagram by 2nd Embodiment of this invention. It is a refrigeration cycle system diagram by 3rd Embodiment of this invention. It is a refrigeration cycle system diagram by 4th Embodiment of this invention. It is a refrigeration cycle system diagram by 5th Embodiment of this invention. It is a refrigeration cycle system diagram by 6th Embodiment of this invention.

Explanation of symbols

  10a, 10b ... outdoor unit, 11a, 11b ... compressor, 12a, 12b ... compressor discharge side check valve, 13a, 13b ... four-way valve, 14a, 14b ... outdoor heat exchanger, 15a, 15b ... outdoor expansion valve, 16a ... Four-way valve, 17a ... Outdoor heat exchanger, 18a ... Outdoor expansion valve, 19a, 19b ... Check valve, 21a, 21b ... Check valve, 22a, 22b ... Check valve, 23a, 23b ... Solenoid valve, 24a 24b ... Check valve, 25a, 25b ... Receiver, 26a, 26b ... Outdoor fan, 31a, 31b ... Liquid blocking valve, 32a, 32b ... High pressure gas blocking valve, 33a, 33b ... Low pressure gas blocking valve, 34a, 34b ... Low pressure gas outdoor unit piping, 35 ... Liquid connection piping, 36 ... High pressure gas connection piping, 37 ... Low pressure gas connection piping, 38a, 38b ... Check valves, 39a, 39b ... Solenoid valves, 40a, 40b, 40c, 40 ... Indoor units, 41a, 41b, 41c, 41d ... Indoor heat exchangers, 42, 42a, 42b, 42c, 42d ... Indoor expansion valves, 50a, 50b, 50c, 50d ... Cooling / heating switching units, 51a, 51b, 51c, 51d ... low pressure side opening / closing mechanism, 52a, 52b, 52c, 52d ... high pressure side opening / closing mechanism, 100 ... multi-type air conditioner.

Claims (7)

A plurality of indoor units having an indoor heat exchanger and an indoor expansion valve;
A plurality of outdoor units having a compressor, a four-way valve switchable between a cooling operation side and a heating operation side, an outdoor heat exchanger, an outdoor expansion valve, a liquid blocking valve, a high pressure gas blocking valve and a low pressure gas blocking valve;
A liquid connection pipe arranged between the indoor unit and the outdoor unit to flow a liquid refrigerant and branched and connected to one side of each indoor unit and the liquid blocking valve of each outdoor unit;
A high-pressure gas connection pipe arranged between the indoor unit and the outdoor unit to flow a high-pressure gas refrigerant and branched and connected to the other side of each indoor unit and the high-pressure gas blocking valve of each outdoor unit When,
A low-pressure gas connection pipe arranged between the indoor unit and the outdoor unit to flow a low-pressure gas refrigerant and branched and connected to the other side of each indoor unit and the low-pressure gas blocking valve of each outdoor unit And comprising
At least one outdoor unit among the plurality of outdoor units includes only one each of the four-way valve and the outdoor heat exchanger, and includes a pipe connecting the low-pressure gas blocking valve and a compressor suction pipe, Provided with a valve mechanism that blocks the flow of refrigerant between the four-way valve and the high-pressure gas blocking valve,
When the to the outdoor unit of the heating operation machine and stopping machine mixed, a state in which the valve mechanism is closed in the stop device,
Of the high-pressure liquid refrigerant condensed by the indoor heat exchanger of the indoor unit, the remaining liquid refrigerant other than the liquid refrigerant sent to the heating operation machine passes through the liquid blocking valve of the stop machine, and then Driving the outdoor fan that blows air to the outdoor heat exchanger of the stop machine and throttles the opening of the outdoor expansion valve of the stop machine so as to evaporate by the outdoor heat exchanger,
The multi-type air conditioner characterized in that the gas refrigerant evaporated by the outdoor heat exchanger of the stop unit is compressed by the compressor of the heating operation unit after passing through the low-pressure gas blocking valve of the stop unit. . The multi-type air conditioner according to claim 1,
When the outdoor heat exchanger is used as a condenser with a large cooling load, the four-way valve is switched to the cooling operation side to connect the discharge side of the compressor to the outdoor heat exchanger side and to the suction side of the compressor Is connected to the high-pressure gas blocking valve side,
When the outdoor heat exchanger is used as an evaporator with a large heating load, or when the cooling load is large and is not used as an evaporator and is pulled to the low pressure side, the four-way valve is switched to the heating operation side so that the discharge side of the compressor is The multi-type air conditioner is connected to the high-pressure gas blocking valve side and the suction side of the compressor is connected to the outdoor heat exchanger side.   2. The multi-type air conditioner according to claim 1, wherein the valve mechanism allows a flow from the four-way valve to the refrigerant to the high-pressure gas blocking valve, and a flow from the high-pressure gas blocking valve to the refrigerant to the four-way valve. A multi-type air conditioner characterized in that it is configured to block air.   2. The multi-type air conditioner according to claim 1, wherein each of the plurality of outdoor units includes only one each of the four-way valve and the outdoor heat exchanger, and connects the low-pressure gas blocking valve and the compressor suction pipe. A multi-type air conditioner comprising a pipe and a valve mechanism for blocking a refrigerant flow between the four-way valve and the high-pressure gas blocking valve.   The multi-type air conditioner according to claim 1, wherein the valve mechanism is constituted by an electromagnetic valve, and the electromagnetic valve is opened when the refrigerant discharged from the compressor is used for heating the indoor unit. Air conditioner.   2. The multi-type air conditioner according to claim 1, wherein the valve mechanism is configured by a solenoid valve, all of the plurality of indoor units are cooling operation units or stop units, and the high-pressure gas connection pipe is used as a low-pressure gas refrigerant channel. In this case, the multi-type air conditioner is characterized in that the low-pressure gas refrigerant is introduced from the high-pressure gas connection pipe to the suction side of the compressor by opening the valve mechanism of the outdoor unit during compressor operation.   The multi-type air conditioner according to claim 1, wherein when the plurality of outdoor units are heating operation units, defrosting of the outdoor heat exchanger of each outdoor unit is performed alternately. Machine.

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