EP3040655A1

EP3040655A1 - Air conditioner

Info

Publication number: EP3040655A1
Application number: EP14867837.8A
Authority: EP
Inventors: Takahiro Kato; Keisuke Mitoma; Takashi Hamachiyo
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Priority date: 2013-12-02
Filing date: 2014-11-17
Publication date: 2016-07-06
Also published as: JP2015105813A; EP3040655A4; WO2015083529A1; JP6407522B2

Abstract

In this air conditioner, at least one indoor unit (3A, 3B) is connected to an outdoor unit (2) via crossover gas piping (4) and crossover liquid piping (5), and a gas-side shutoff valve (36) and a liquid-side shutoff valve (35) are provided in the crossover gas piping (4) and the crossover liquid piping (5) in the vicinity of a gas-side operation valve (19) and a liquid-side operation valve (20) provided in a coolant circuit (22) of the outdoor unit (2). An outdoor control device (27) is equipped with: an emergency shutdown control function for closing the liquid-side shutoff valve (35) in response to an emergency shutoff signal, causing operation to continue as a cooling cycle and, upon a low-pressure reaching a set pressure, closing the gas-side shutoff valve (36) and stopping the operation of the air conditioner (1); and an output terminal (37) for outputting a shutoff signal to the gas-side shutoff valve (36) and the liquid-side shutoff valve (35).

Description

Technical Field

The present invention relates to an air conditioner provided with a function for stopping the operation of the air conditioner in the event of an emergency such as a disaster or coolant leakage.

Background Art

A conventional air conditioner is provided with an emergency shutdown function for immediately stopping the operation of the air conditioner in response to an input signal from an external device or a unit built-in device when an emergency shutdown situation occurs, such as a disaster including an earthquake or a fire, or coolant leakage.
On the other hand, there are provided air conditioners configured to, when such an emergency shutdown situation occurs, close a solenoid valve or an electronic expansion valve provided in a high-pressure liquid piping of a coolant circuit, cause a refrigerating cycle to operate in a cooling cycle, move a coolant from an indoor unit to an outdoor unit and, upon the pressure of a low-pressure portion being equal to or less than a set pressure, close a solenoid valve provided in a low-pressure gas piping or maintain a four-way selector valve in a cooling position, thereby causing the coolant to be stored in an outdoor heat exchanger or the like of the outdoor unit and preventing coolant outflow to indoor areas (refer to Patent Documents 1 to 3).

Citation List

Patent Literature

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2000-28238A
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2000-274847A
Patent Document 3: Japanese Patent No. 3530983B

Summary of the Invention

Technical Problem

However, the air conditioners described in Patent Documents 1 to 3 are configured to include a valve such as a solenoid valve in the coolant circuit, the valve being opened/closed at the occurrence of an emergency shutdown situation, and to open/close the solenoid valve via a control device in order to move the coolant from the indoor unit to the outdoor unit and store the coolant in the outdoor unit at the occurrence of an emergency shutdown situation. According to such a configuration, it is not possible to select and use as desired any one of the air conditioners with and without an emergency shutdown control function.
Therefore, in order to make it possible to select and use as desired an air conditioner having either configuration, it is essential to produce in advance two types of air conditioners having different configurations as described above. This has led to decreases in production efficiency and complexities in product management.
In light of the above, an object of the present invention is to provide an air conditioner configured to selectively add an emergency shutdown control function thereto, and to simplify selection of an air conditioner from those with and without the emergency shutdown control function.

Solution to Problem

In order to solve the above-described problem, the air conditioner of the present invention provides the following means.
That is, the air conditioner according to the present invention includes an outdoor unit including an outdoor control device; at least one indoor unit connected to the at least one outdoor unit via crossover gas piping and crossover liquid piping; a gas-side operation valve and a liquid-side operation valve provided in a coolant circuit of the outdoor unit; and a gas-side shutoff valve and a liquid-side shutoff valve provided in the crossover gas piping and the crossover liquid piping in a vicinity of the gas-side operation valve and the liquid-side operation valve. The outdoor control device includes an emergency shutdown control function and an output terminal, the emergency shutdown control function being configured to close the liquid-side shutoff valve in response to an emergency shutoff signal, cause operation to continue as a cooling cycle, and close the gas-side shutoff valve and stop the operation of the air conditioner upon the pressure of a low-pressure portion reaching a set pressure, and the output terminal being configured to output a shutoff signal to the gas-side shutoff valve and the liquid-side shutoff valve.
According to the present invention, the air conditioner in which the indoor unit is connected to the outdoor unit via the crossover gas piping and the crossover liquid piping includes the gas-side shutoff valve and the liquid-side shutoff valve provided in the crossover gas piping and the crossover liquid piping in the vicinity of the gas-side operation valve and the liquid-side operation valve provided in the coolant circuit of the outdoor unit for connecting the crossover gas piping and the crossover liquid piping. Further, the outdoor control device includes the emergency shutdown control function configured to close the liquid-side shutoff valve in response to the emergency shutoff signal, cause operation to continue as the cooling cycle, and upon the pressure of the low-pressure portion reaching a set pressure, close the gas-side shutoff valve and stop the operation of the air conditioner; and the output terminal configured to output the shutoff signal to the gas-side shutoff valve and the liquid-side shutoff valve. Therefore, an air conditioner configured to include the emergency shutdown control function can be installed by providing the gas-side shutoff valve and the liquid-side shutoff valve in the crossover gas piping and the crossover liquid piping connected to the gas-side operation valve and the liquid-side operation valve in the outdoor unit, and electrically connecting the gas-side shutoff valve and the liquid-side shutoff valve to the output terminal of the outdoor control device to enable the gas-side shutoff valve and the liquid-side shutoff valve to be closed by the outdoor control device during onsite installation. On the other hand, an air conditioner configured to not include the emergency shutdown control function can be installed by directly connecting the crossover gas piping and the crossover liquid piping to the gas-side operation valve and the liquid-side operation valve without providing the gas-side shutoff valve and the liquid-side shutoff valve in the crossover gas piping and the crossover liquid piping. This makes it possible to achieve common use of the outdoor unit that includes the outdoor control device with the emergency shutdown control function and to easily select any one of the air conditioners with and without the emergency shutdown control function depending on the gas-side shutoff valve and the liquid-side shutoff valve being provided or not provided in the crossover gas piping and the crossover liquid piping during onsite installation, thereby making it possible to prevent decreases in production efficiency and eliminate complexities in product management.
Furthermore, the air conditioner of the present invention according to the above-described air conditioner is configured as a multi-type air conditioner having a plurality of the indoor units connected in parallel to the crossover gas piping and the crossover liquid piping, and includes a receiver provided in the coolant circuit of the outdoor unit.
According to the present invention, the air conditioner is configured as the multi-type air conditioner having the plurality of indoor units connected in parallel to the crossover gas piping and the crossover liquid piping, and includes the receiver provided in the coolant circuit of the outdoor unit. Therefore, during emergency shutdown control, it is possible to move the coolant from the plurality of indoor units to the outdoor unit, and store the coolant in devices, including an outdoor heat exchanger and the receiver, of the outdoor unit. Thus, by suitably setting a capacity of the receiver and the like and storing the coolant in the cycle into the outdoor unit, it is possible to reduce the risk of coolant outflow from the indoor units to indoor areas when an emergency shutdown situation occurs, such as a disaster or coolant leakage.
Furthermore, in the air conditioner of the present invention according to any one of the above-described air conditioners, the outdoor control device includes an immediate emergency shutdown function and the emergency shutdown control function, the immediate emergency shutdown function being configured to immediately stop the operation of the air conditioner in response to the emergency shutoff signal, the emergency shutdown control function being configured to stop the operation of the air conditioner after a coolant is moved to the outdoor unit by the emergency shutdown control in response to the emergency shutoff signal, and the outdoor control device is capable of selectively activate any one of the functions.
According to the present invention, the outdoor control device includes the immediate emergency shutdown function for immediately stopping the operation of the air conditioner in response to the emergency shutoff signal, and the emergency shutdown control function for stopping the operation of the air conditioner after the coolant is moved to the outdoor unit by the emergency shutdown control in response to the emergency shutoff signal, and the outdoor control device is capable of selectively activate any one of the functions. Therefore, the emergency shutdown function of the air conditioner performed by the outdoor control device can be selectively switched to any one of the immediate emergency shutdown function for immediately stopping the air conditioner in response to the emergency shutoff signal and the emergency shutdown control function for stopping the air conditioner after the coolant is moved to the outdoor unit, by a switch, for example. This makes it possible to select and set as desired any one of the emergency shutdown functions in accordance with the conditions of air conditioner installation and the like.
Furthermore, in the air conditioner of the present invention according to any one of the above-described air conditioners, the outdoor control device is configured to be activated in response to an input of the emergency shutoff signal from an external device or a unit built-in device.
According to the present invention, the outdoor control device can be activated in response to the input of the emergency shutoff signal from the external device or the unit built-in device, making it possible to activate the emergency shutdown function of the outdoor control device in response to the input of the emergency shutoff signal from the external device (such as a fire alarm or a seismometer) or the emergency shutoff signal from the unit built-in device (such as a coolant leakage detector). This allows the outdoor control device to fully exert the functions on a variety of emergency shutdown situations in order to urgently stop the air conditioner in a required state, thereby making it possible to achieve the initial object.

Advantageous Effects of Invention

Therefore, an air conditioner configured to include the emergency shutdown control function can be installed by providing the gas-side shutoff valve and the liquid-side shutoff valve in the crossover gas piping and the crossover liquid piping connected to the gas-side operation valve and the liquid-side operation valve in the outdoor unit, and electrically connecting the gas-side shutoff valve and the liquid-side shutoff valve to the output terminal of the outdoor control device to enable the gas-side shutoff valve and the liquid-side shutoff valve to be closed by the outdoor control device during onsite installation. On the other hand, an air conditioner configured to not include the emergency shutdown control function can be installed by directly connecting the crossover gas piping and the crossover liquid piping to the gas-side operation valve and the liquid-side operation valve without providing the gas-side shutoff valve and the liquid-side shutoff valve in the crossover gas piping and the crossover liquid piping. This makes it possible to achieve common use of the outdoor unit that includes the outdoor control device with the emergency shutdown control function and to easily select any one of the air conditioners with and without the emergency shutdown control function depending on the gas-side shutoff valve and the liquid-side shutoff valve being provided or not provided in the crossover gas piping and the crossover liquid piping during onsite installation, thereby making it possible to prevent decreases in production efficiency and eliminate complexities in product management.

Brief Description of Drawings

FIG. 1 is a configuration diagram of an air conditioner according to an embodiment of the present invention.
FIG. 2 is a flowchart of control during abnormal operation of the air conditioner illustrated in FIG. 1.

Description of Embodiments

The following is a description of an embodiment of the present invention with reference to FIGS. 1 and 2.
FIG. 1 illustrates a configuration diagram of an air conditioner according to the embodiment of the present invention, and FIG. 2 illustrates a flowchart of control during abnormal operation of the air conditioner.
An air conditioner 1 is a multi-type air conditioner having a plurality of indoor units 3A, 3B connected in parallel to one outdoor unit 2 via branching devices 6 located between the indoor units 3A, 3B, and crossover gas piping 4 and crossover liquid piping 5 that extend from the outdoor unit 2.
The outdoor unit 2 includes an inverter-driven compressor 10 that compresses a coolant, an oil separator 11 that separates oil from a coolant gas, a four-way selector valve 12 that switches circulation directions of the coolant, an outdoor heat exchanger 13 that causes heat to be exchanged between the coolant and outside air, an outdoor electronic expansion valve (EEVH) 14, a receiver 15 that stores a liquid coolant, a supercooling heat exchanger 16 that supercools the liquid coolant, an electronic expansion valve for supercooling (EEVSC) 17 that controls a coolant amount to be distributed to the supercooling heat exchanger 16, an accumulator 18 that separates a liquid portion from the coolant gas to be suctioned into the compressor 10 and causes only a gas portion to be suctioned into the compressor 10, a gas-side operation valve 19, and a liquid-side operation valve 20.
The above-described devices in the outdoor unit 2 are connected with each other via coolant piping 21 as known, and constitute the outdoor coolant circuit 22. Further, an oil return circuit 23 for returning the oil separated by the oil separator 11 in predetermined amounts as well as a high-pressure switch 24, a high-pressure sensor 25, a low-pressure sensor 26, an outdoor control device 27, an outdoor fan (not illustrated) that blows outside air to the outdoor heat exchanger 13, and the like are provided in the outdoor unit 2.
The crossover gas piping 4 and the crossover liquid piping 5 serve as coolant piping connected to the gas-side operation valve 19 and the liquid-side operation valve 20 in the outdoor unit 2. During onsite installation, the piping lengths are determined in accordance with a distance between the outdoor unit 2 and the plurality of indoor units 3A, 3B connected to the outdoor unit 2. A suitable number of the branching devices 6 are provided on the way of the crossover gas piping 4 and the crossover liquid piping 5, and a suitable number of indoor units 3A, 3B are connected in parallel via the branching devices 6. As a result, the refrigerating cycle (coolant circuit) 7 of one closed system is configured.
The indoor units 3A, 3B each include an indoor heat exchanger 28 that exchanges heat between the inside air and the coolant and uses the heat exchanged air for inside air conditioning, an indoor electronic expansion valve (EEVC) 29, an indoor fan (not illustrated) that circulates the inside air to the indoor heat exchanger 28, and the like. The indoor units 3A, 3B are connected to the branching devices 6 via branching gas piping 4A, 4B and branching liquid piping 5A, 5B on the indoor side.
A cooling operation of the air conditioner 1 described above is performed as follows.
High-pressure, high-temperature coolant gas that has been compressed and discharged by the compressor 10 is subjected to oil separation by the oil separator 11, separating the oil included in the coolant. Subsequently, the coolant gas is circulated toward the outdoor heat exchanger 13 by the four-way selector valve 12, and is subjected to heat exchange with the outside air blown by the outdoor fan in the outdoor heat exchanger 13 to be condensed and liquefied. This liquid coolant passes through the outdoor electronic expansion valve 14 and is temporarily stored in the receiver 15.
The circulation amount of the liquid coolant which has been adjusted by the receiver 15, flows through the liquid piping side via the supercooling heat exchanger 16. In this process, a portion of the liquid coolant is distributed from the liquid piping and subjected to heat exchange with coolant adiabatically expanded by the electronic expansion valve for supercooling (EEVSC) 17, imparting a degree of supercooling to the liquid coolant. This liquid coolant is introduced from the outdoor unit 2 to the crossover liquid piping 5 via the liquid-side operation valve 20. Furthermore, the liquid coolant introduced to the crossover liquid piping 5 is distributed to the branching liquid piping 5A, 5B of the indoor units 3A, 3B via the branching devices 6.
The liquid coolant distributed to the branching liquid piping 5A, 5B is introduced to the indoor units 3A, 3B, adiabatically expanded by the indoor electronic expansion valve (EEVC) 29 to form a gas-liquid two-phase flow, and introduced to the indoor heat exchanger 28. In the indoor heat exchanger 28, the inside air circulated by the indoor fan is subjected to heat exchange with the coolant so as to be cooled, and is used for indoor cooling. Meanwhile, the coolant is evaporated to become a gas, led to the branching devices 6 through the branching gas piping 4A, 4B, and merged with a coolant gas from the other indoor unit in the crossover gas piping 4.
The coolant gas merged in the crossover gas piping 4 returns once again to the outdoor unit 2. In the outdoor unit 2, the coolant gas, passing through the gas-side operation valve 19 and the four-way selector valve 12, is merged with the coolant gas from the supercooling heat exchanger 16 and then introduced to the accumulator 18. In the accumulator 18, the liquid portion included in the coolant gas is separated, and only the gas portion is suctioned into the compressor 10. This coolant is once again compressed in the compressor 10, and the cooling operation is performed by repeating the above cycle.
On the other hand, a heating operation is performed as follows.
High-pressure, high-temperature coolant gas that has been compressed and discharged by the compressor 10 is subjected to oil separation by the oil separator 11, separating the oil included in the coolant. The coolant gas is then circulated toward the gas-side operation valve 19 via the four-way selector valve 12. The coolant circulated toward the gas-side operation valve 19 is fed from the outdoor unit 2 through the crossover gas piping 4. Then, the coolant is introduced to the plurality of indoor units 3A, 3B via the branching devices 6 and through the branching gas piping 4A, 4B on the indoor side.
The high-pressure, high-temperature coolant gas introduced to the indoor units 3A, 3B is subjected to heat exchange with the inside air circulated via the indoor fan by the indoor heat exchanger 30, and the inside air is heated and then used for heating. Meanwhile, the liquid coolant condensed and liquefied by the indoor heat exchanger 28 is led to the branching devices 6 via the indoor electronic expansion valve (EEVC) 29 and through the branching liquid piping 5A, 5B, merged with the liquid coolant from the other indoor unit, and then returned to the outdoor unit 2 through the crossover liquid piping 5.
It should be noted that, during the heating operation, an opening of the indoor electronic expansion valve (EEVC) 29 in the indoor units 3A, 3B is controlled so that a coolant outlet temperature (hereinafter referred to as "heat exchange outlet temperature") of the indoor heat exchanger 28 that functions as a condenser, or the degree of supercooling of coolant becomes a target value. The coolant returned to the outdoor unit 2 is led to the supercooling heat exchanger 16 via the liquid-side operation valve 20, supercooled in the same manner as during cooling, and introduced to and temporarily stored in the receiver 15, thereby adjusting the circulation amount. This liquid coolant is supplied to the outdoor electronic expansion valve (EEVH) 14, adiabatically expanded, and then introduced to the outdoor heat exchanger 13.
In the outdoor heat exchanger 13, the coolant is subjected to heat exchange with the outside air blown via the outdoor fan so as to absorb heat from the outside air, thereby evaporating the coolant to be a gas. This coolant is passed from the outdoor heat exchanger 13 via the four-way selector valve 12, merged with the coolant gas from the supercooling heat exchanger 16, and introduced to the accumulator 18. In the accumulator 18, the liquid portion included in the coolant gas is separated, and only the gas portion is suctioned into the compressor 10 and once again compressed by the compressor 10. The heating operation is performed by repeating the above cycle.
Furthermore, in the present embodiment, the outdoor control device 27 that controls the operation of the air conditioner 1 includes an emergency shutdown controller that urgently stops the operation of the air conditioner 1 when an emergency shutdown situation occurs, such as a disaster including an earthquake and a fire, or coolant leakage.
This emergency shutdown controller is composed of an immediate emergency shutdown portion 32 that immediately stops the operation of the air conditioner 1 upon an emergency shutoff signal being inputted from an external device 30 (such as a fire alarm or a seismometer) or a unit built-in device 31 (such as a coolant leakage detector), and an emergency shutdown controller 33 that stops the operation of the air conditioner 1 after moving the coolant in the indoor units 3A, 3B to the outdoor unit 2. The emergency shutdown controller is configured to selectively activate any one of the immediate emergency shutdown portion 32 and the emergency shutdown controller 33 by a switch 34.
The immediate emergency shutdown portion 32 has a function of immediately stopping the operation of the air conditioner 1 upon the emergency shutoff signal being inputted from the external device 30 or the unit built-in device 31.
On the other hand, the emergency shutdown controller 33 has a function of stopping the operation of the air conditioner 1 after the coolant in the indoor units 3A, 3B is pumped and moved to the outdoor unit 2, that is, after a so-called pump-down operation is performed, as illustrated in FIG. 2. The function of this emergency shutdown controller 33 is described in detail below on the basis of FIG. 2.
First, upon the emergency shutoff signal being inputted from the external device 30 or the unit built-in device 31 in step S1, the flow proceeds to step S2 in which the liquid-side shutoff valve 35 is closed. Subsequently, the flow proceeds to step S3 in which whether or not the cooling operation is in progress is determined. If the cooling operation is in progress, the refrigerating cycle 7 is maintained in the cooling cycle and the flow proceeds to step S4. If the heating operation is in progress, the flow proceeds to step S5 in which the heating cycle is switched to the cooling cycle, and then the flow proceeds to step S4. In step S4, operation is continued with a drive frequency of the compressor 10 set to a set frequency.
The pump-down operation by this cooling cycle causes the coolant in the indoor units 3A, 3B to be pumped into a device, such as the outdoor heat exchanger 13 or the receiver 15 in the outdoor unit 2, or the coolant piping. During the pump-down operation, low pressure is monitored by the low-pressure sensor 26 in step S6, and upon the detection value of the low-pressure sensor 26 being equal to or less than the value of a set pressure by the pumping of the coolant to the outdoor unit 2, the flow proceeds to step S7 in which a gas-side shutoff valve 36 is closed and the compressor 10 is stopped, thereby stopping the operation of the air conditioner 1. As a result, the operation of the air conditioner 1 can be stopped with the coolant stored in the outdoor unit 2.
Further, the liquid-side shutoff valve 35 and the gas-side shutoff valve 36 to be closed by the emergency shutdown controller 33 during emergency shutdown are solenoid valves. As illustrated in FIG. 1, the liquid-side shutoff valve 35 and the gas-side shutoff valve 36 are installed in the crossover gas piping 4 and the crossover liquid piping 5 in the vicinity of the gas-side operation valve 19 and the liquid-side operation valve 20 provided in the outdoor coolant circuit 22 of the outdoor unit 2. Then, these liquid-side shutoff valve 35 and gas-side shutoff valve 36 are installed so as to connect to the crossover gas piping 4 and the crossover liquid piping 5 and electrically connected to a signal output terminal 37 of the outdoor control device 27 during onsite installation of the air conditioner 1. Thus, the liquid-side shutoff valve 35 and gas-side shutoff valve 36 are closed in response to the shutoff signal from the emergency shutdown controller 33 during emergency shutdown as described above.
According to the configuration as described above, the present embodiment has the following action and effects.
In the above-described air conditioner 1, upon the occurrence of an emergency shutdown situation, such as a disaster including an earthquake and a fire or coolant leakage, a method of urgently stopping the air conditioner 1 by the outdoor control device 27 after receiving the emergency shutoff signal from the external device 30 (such as a fire alarm or a seismometer) or the unit built-in device 31 (such as a coolant leakage detector) that has detected the emergency shutdown situation can be switched to the following (1) or (2) by the switch 34.

(1) Selectively set the immediate emergency shutdown portion 32 and, upon the emergency shutoff signal being inputted, immediately stop the operation of the air conditioner 1.
(2) Selectively set the emergency shutdown controller 33 and, upon the emergency shutoff signal being inputted, stop the operation of the air conditioner 1 after the coolant in the indoor units 3A, 3B is pumped and moved to the outdoor unit 2, that is, after the so-called pump-down operation is performed.

In the emergency shutdown when the emergency shutdown controller 33 has been selectively set as described in (2) above, the liquid-side shutoff valve 35 is first closed in response to the emergency shutoff signal. Then, if the cooling operation is in progress, the cooling cycle is maintained, and if the heating operation is in progress, the heating cycle is switched to the cooling cycle, and the operation is continued. This pump-down operation causes the coolant in the indoor units 3A, 3B to be pumped to the outdoor unit 2 and stored in a device such as the outdoor heat exchanger 13 or the receiver 15, or in the coolant piping. Upon the detection value of the low-pressure sensor 26 being equal to or less than the value of the set pressure by the pumping and movement of the coolant, the gas-side shutoff valve 36 is closed, and the operation of the air conditioner 1 is stopped.
As a result, the coolant filling the refrigerating cycle 7 of the air conditioner 1 is pumped to and stored in the outdoor unit 2. In this state, the air conditioner 1 is stopped. Therefore, even if an emergency shutdown situation occurs, it is possible to prevent coolant outflow from the indoor units 3A, 3B to indoor areas.
On the other hand, in the present embodiment, when the air conditioner 1 is urgently stopped as the above-described (2), the emergency shutdown control function of stopping the air conditioner 1 with the coolant moved from the indoor units 3A, 3B to the indoor unit 2 is added. Therefore, the liquid-side shutoff valve 35 and the gas-side shutoff valve 36 are installed in the crossover gas piping 4 and the crossover liquid piping 5 in the vicinity of the gas-side operation valve 19 and the liquid-side operation valve 20 having connected thereto the crossover gas piping 4 and the crossover liquid piping 5 in the outdoor unit 2. Further, this liquid-side shutoff valve 35 and the gas-side shutoff valve 36 are electrically connected to the signal output terminal 37 of the outdoor control device 27, making it possible to close the liquid-side shutoff valve 35 and the gas-side shutoff valve 36 in response to the shutoff signal from the emergency shutdown controller 33 during emergency shutdown as described above.
As a result, in the air conditioner 1 configured to include the emergency shutdown control function, it is only necessary to optionally provide the liquid-side shutoff valve 35 and the gas-side shutoff valve 36 at the above-described positions in the crossover gas piping 4 and the crossover liquid piping 5, connect the crossover gas piping 4 and the crossover liquid piping 5 to the gas-side operation valve 19 and the liquid-side operation valve 20, and electrically connect the liquid-side shutoff valve 35 and the gas-side shutoff valve 36 to the signal output terminal 37 of the outdoor control device 27 during onsite installation. Further, in order to install the air conditioner configured to not include the emergency shutdown control function, it is only necessary to connect the crossover gas piping 4 and the crossover liquid piping 5 without the liquid-side shutoff valve 35 and the gas-side shutoff valve 36 to the gas-side operation valve 19 and the liquid-side operation valve 20 of the outdoor unit 2 which commonly use the outdoor control device 27.
According to the present embodiment, this makes it possible to achieve common use of the outdoor unit 2 that includes the outdoor control device 27 with an emergency shutdown control function, and to easily select any one of the air conditioners 1 with and without the emergency shutdown control function depending on the gas-side shutoff valve 35 and the liquid-side shutoff valve 36 being provided or not provided in the crossover gas piping 4 and the crossover liquid piping 5 during onsite installation, thereby making it possible to prevent decreases in production efficiency and to eliminate complexities in product management.
Further, the air conditioner 1 is configured as a multi-type air conditioner having the plurality of indoor units 3A, 3B connected in parallel to the crossover gas piping 4 and the crossover liquid piping 5, and includes the receiver 15 provided in the coolant circuit 22 of the outdoor unit 2. Therefore, during emergency shutdown control, it is possible to move the coolant from the plurality of indoor units 3A, 3B to the outdoor unit 2, and store the coolant in devices, including the outdoor heat exchanger 13 and the receiver 15, of the outdoor unit 2. Thus, by suitably setting a capacity of the receiver 15 and the like and storing the coolant in the cycle into the outdoor unit 2, it is possible to prevent coolant outflow from the indoor units 3A, 3B to indoor areas when an emergency shutdown situation occurs, such as a disaster or coolant leakage.
Furthermore, in the present embodiment, the outdoor control device 27 includes the immediate emergency shutdown function for immediately stopping the operation of the air conditioner 1 in response to the emergency shutoff signal, and the emergency shutdown control function for stopping the operation of the air conditioner 1 after the coolant is moved to the outdoor unit 2 by the emergency shutdown control in response to the emergency shutoff signal, and the outdoor control device 27 is configured to selectively activate any one of the functions by the switch 34.
Therefore, the emergency shutdown function of the air conditioner 1 performed by the outdoor control device 27 can be easily switched, by the switch 34, to any one of the immediate emergency shutdown function for immediately stopping the air conditioner 1 in response to the emergency shutoff signal and the emergency shutdown control function for stopping the air conditioner 1 after the coolant is moved to the outdoor unit 2, allowing any one of the emergency shutdown functions to be selected and set as desired in accordance with the conditions of installation of the air conditioner 1 and the like.
Further, the outdoor control device 27 can be activated in response to the input of the emergency shutoff signal from the external device 30 (such as a fire alarm or a seismometer) or the unit built-in device 31 (such as a coolant leakage detector). This makes it possible to activate the emergency shutdown function of the outdoor control device 27 in response to the input of the emergency shutoff signal from the external device 30 (such as a fire alarm or a seismometer) or the unit built-in device 31 (such as a coolant leakage detector). This allows the outdoor control device 27 to fully exert the functions on a variety of emergency shutdown situations in order to urgently stop the air conditioner 1 in a required state, thereby making it possible to achieve the initial object.
Note that the present invention is not limited to the above-described embodiment, and changes can be made as appropriate without departing from the scope of the present invention. For example, while the above embodiment has described an example in which the present invention is applied to the multi-type air conditioner 1, it is needless to say that the present invention is applicable to a single-type air conditioner having one indoor unit connected thereto in the same manner.

Reference Signs List

1: Air conditioner
2: Outdoor unit
3A, 3B: Indoor unit
4: Crossover gas piping
5: Crossover liquid piping
15: Receiver
19: Gas-side operation valve
20: Liquid-side operation valve
22: Outdoor coolant circuit
26: Low-pressure sensor
27: Outdoor control device
30: External device
31: Unit built-in device
32: Immediate emergency shutdown portion
33: Emergency shutdown controller
34: Switch
35: Liquid-side shutoff valve
36: Gas-side shutoff valve
37: Output terminal

Claims

An conditioner comprising:
an outdoor unit including an outdoor control device;

at least one indoor unit connected to the outdoor unit via crossover gas piping and crossover liquid piping;

a gas-side operation valve and a liquid-side operation valve provided in a coolant circuit of the outdoor unit; and

a gas-side shutoff valve and a liquid-side shutoff valve provided in the crossover gas piping and the crossover liquid piping in a vicinity of the gas-side operation valve and the liquid-side operation valve;

the outdoor control device including an emergency shutdown control function and an output terminal, the emergency shutdown control function being configured to close the liquid-side shutoff valve in response to an emergency shutoff signal, cause operation to continue as a cooling cycle, and close the gas-side shutoff valve and stop the operation of the air conditioner upon a low-pressure reaching a set pressure, and the output terminal being configured to output a shutoff signal to the gas-side shutoff valve and the liquid-side shutoff valve.
The air conditioner according to claim 1, the air conditioner being configured as a multi-type air conditioner that includes the indoor units connected in parallel to the crossover gas piping and the crossover liquid piping, and including a receiver provided in the coolant circuit of the outdoor unit.
The air conditioner according to claim 1 or 2, wherein
the outdoor control device includes an immediate emergency shutdown function and the emergency shutdown control function, the immediate emergency shutdown function being configured to immediately stop the operation of the air conditioner in response to the emergency shutoff signal, the emergency shutdown control function being configured to stop the operation of the air conditioner after a coolant is moved to the outdoor unit by the emergency shutdown control in response to the emergency shutoff signal, and the outdoor control device being capable of selectively activate any one of the functions.
The air conditioner according to any one of claims 1 to 3, wherein
the outdoor control device is configured to be activated in response to an input of the emergency shutoff signal from an external device or a unit built-in device.