JP2651014B2 - Multi-room air conditioner - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant cycle of a multi-room air conditioner, and more particularly to a refrigerant leak detection.

2. Description of the Related Art Conventionally, a refrigerant cycle of a multi-room cooling / heating device in which a heat source-side refrigerant cycle and a use-side refrigerant cycle are separated and heat is exchanged by an auxiliary heat exchanger is as shown in FIG. In the figure, 11 is a compressor, 12 is a four-way valve, 13 is a heat source side heat exchanger,
14 is a cooling decompression device, 15 is a heating decompression device, 16 is a check valve that closes the cooling decompression device 14 during heating, 17 is a check valve that closes the heating decompression device 15 during cooling, and 18 is a check valve. These are connected annularly by the first auxiliary heat exchanger to form a heat source side refrigerant cycle. Reference numeral 19 denotes a second auxiliary heat exchanger, which is a first auxiliary heat exchanger.
And are formed integrally so as to exchange heat. Reference numeral 20 denotes a refrigerant amount adjusting tank for adjusting the amount of refrigerant during cooling and during heating.
Reference numeral 21 denotes a refrigerant transport device having reversible characteristics in which the refrigerant flows in opposite directions during cooling and during heating, and these are housed in the outdoor unit f. i, i ', j, j' and 22a, 22b are utilization side heat exchangers housed in the indoor units g, h and connected to the outdoor unit f by connection piping. The second auxiliary heat exchanger 19
And refrigerant adjustment tank 20, refrigerant transfer device 21, user side heat exchanger
22a, 22b and the connection pipes i, i ', j, j' are connected in an annular shape to form a use-side refrigerant cycle.

The operation of the multi-room air-conditioning apparatus configured as described above will be described.

In the cooling operation, the refrigerant cycle is as indicated by the solid line in the figure. The pressure is reduced by the cooling decompression device 14, evaporated in the first auxiliary heat exchanger 18, and circulated to the compressor 11 through the four-way valve 12. At this time, the second auxiliary heat exchanger 19 of the utilization side refrigerant cycle
And the first auxiliary heat exchanger 18 exchanges heat, the gas refrigerant in the use-side refrigerant cycle is cooled and liquefied, sent to the refrigerant transfer device 21 through the refrigerant amount adjustment tank 20, and is transferred to the refrigerant transfer device 21. Through the connection pipes i, j to use side heat exchangers 22a, 22
It is sent to 2b where it is absorbed and vaporized, gasified, and connected pipes i ', j'
And circulates to the second auxiliary heat exchanger 19.

On the other hand, during the heating operation, the refrigerant cycle is indicated by a broken line in the drawing, and in the heat source side refrigerant cycle, the high-temperature and high-pressure refrigerant from the compressor 11 is sent from the four-way valve 12 to the first auxiliary heat exchanger 18 where heat is released and condensed. Liquefaction, decompression device for heating from check valve 17
The pressure is reduced at 15, the heat is absorbed and evaporated at the heat source side heat exchanger 13, and the four-way valve 12
And circulates through the compressor 11. At this time, the second auxiliary heat exchanger 19 of the use side refrigerant cycle and the first auxiliary heat exchanger 18 exchange heat, the liquid refrigerant in the use side refrigerant cycle is heated and gasified, and the connection pipes i ′, j ′ To the use-side heat exchanger 22, and is heated and radiated and liquefied, sent to the refrigerant transfer device 21 through the connection pipes i and j, and circulated from the refrigerant amount adjustment tank 20 to the second auxiliary heat exchanger 19. I do.

Problems to be Solved by the Invention However, in the above configuration, when the refrigerant in the use-side refrigerant cycle gradually leaks, the capacity of the indoor unit is not significantly affected to some extent, but at a certain point, a large amount of refrigerant is supplied to the refrigerant transfer device. When the gas refrigerant is sucked in, the amount of the circulated refrigerant is extremely reduced, and the capacity of the indoor unit is sharply reduced. In addition, the lubrication of the refrigerant conveyance device is insufficient, and the refrigerant conveyance device may be damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a multi-room cooling / heating apparatus that detects a refrigerant leak in a use-side refrigerant cycle with a simple configuration and does not cause damage to a refrigerant transport device due to the refrigerant leak.

Means for Solving the Problems In order to solve the above problems, a multi-room cooling / heating apparatus of the present invention separates a heat source side refrigerant cycle and a use side refrigerant cycle, and detects a refrigerant pressure of the heat source side refrigerant cycle. A pressure detection device, a usage-side pressure detection device that detects a refrigerant pressure of the usage-side refrigerant cycle, and a control device that detects refrigerant leakage of the usage-side refrigerant cycle based on a pressure difference detected by the two pressure detection devices. Things.

Operation According to the above-described configuration of the present invention, since the control is performed based on the pressure difference between the heat source-side refrigerant cycle and the use-side refrigerant cycle, it is possible to reliably detect the refrigerant leakage of the use-side refrigerant cycle in advance, and the control device is simplified. It will be.

Embodiment Hereinafter, a cooling and heating apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a refrigerant cycle of a multi-stage cooling and heating apparatus according to an embodiment of the present invention.

The basic configuration is the same as that of the conventional example shown in FIG. 2, and only the different points will be described here. In the figure, 31a is a heat source side pressure detecting device for detecting the refrigerant pressure of the heat source side refrigerant cycle, 31b is a use side pressure detecting device for detecting the refrigerant pressure of the use side refrigerant cycle, and the outdoor unit f is connected to the heat source side refrigerant cycle and the use side, respectively. Attached to the refrigerant cycle piping. 32 is a heat source side pressure detector 31a and a use side pressure detector 3
This is a control device that detects refrigerant leakage in the use-side refrigerant cycle based on the pressure difference detected in 1b.

The operation of the multi-room air-conditioning apparatus configured as described above will be described.

The basic operation of the refrigerant cycle is the same as that of the conventional example. Here, the difference, that is, the refrigerant leak detection operation of the use-side refrigerant cycle will be described.

During the cooling and heating operation, the pressure of the heat source side refrigerant cycle and the pressure of the use side refrigerant cycle are adjusted so that the capacity of the heat source side refrigerant cycle and the capacity of the refrigerant transfer device 21 are operated at a certain pressure difference depending on the load of the indoor units g and h. Controlling.

Therefore, when the refrigerant of the use side refrigerant cycle leaks,
Even if a certain amount (for example, 20 to 30%) of the refrigerant leaks, the capacity of the indoor units g and h does not change much due to an increase in the capacity of the heat source side refrigerant cycle and an increase in the capacity of the refrigerant transfer device 21.

However, the pressure difference between the refrigerant pressure of the heat source-side refrigerant cycle (low pressure side pressure in the cooling operation and high pressure side pressure in the heating operation) and the refrigerant pressure of the use side refrigerant cycle gradually increases. This is detected by both pressure detection devices, and when this pressure difference exceeds a certain value, that is, a large amount of gas refrigerant flows into the refrigerant transfer device 21, the refrigerant transfer capacity is extremely reduced, and the cooling and heating capacity is greatly reduced. At the same time, an abnormality is displayed and the operation of the cooling / heating device is stopped before the bearing is damaged due to insufficient lubrication of the bearing portion of the refrigerant transfer device 21.

As described above, according to the present embodiment, a heat-source-side pressure detection device that detects the refrigerant pressure of the heat-source-side refrigerant cycle and a utilization-side pressure detection device that detects the refrigerant pressure of the utilization-side refrigerant cycle,
A control device that detects refrigerant leakage in the use-side refrigerant cycle based on the pressure difference detected by the two pressure detection devices is provided, so that refrigerant leakage can be reliably detected at an early stage with a simple configuration, and the cooling and heating capacity is improved. It can prevent a sharp drop and damage to the refrigerant transport device.

Effect of the Invention As described above, the present invention provides a heat source side pressure detection device that detects the refrigerant pressure of the heat source side refrigerant cycle, a utilization side pressure detection device that detects the refrigerant pressure of the utilization side refrigerant cycle, and both of these pressure detection devices. With a control device that detects refrigerant leakage in the use-side refrigerant cycle based on the detected pressure difference, the refrigerant leakage can be detected quickly and reliably with a simple configuration. This has the effect of preventing damage due to lowering and insufficient lubrication of the bearing portion of the refrigerant transport device.

[Brief description of the drawings]

FIG. 1 is a refrigerant cycle diagram of a multi-room cooling / heating device according to an embodiment of the present invention, and FIG. 2 is a refrigerant cycle diagram of a conventional multi-room cooling / heating device. 11 Compressor 13 Heat source side heat exchanger 18 First auxiliary heat exchanger 19 Second auxiliary heat exchanger 21 Refrigerant transfer device 22a, 22b Usage side heat Exchanger, 31a ... heat source side pressure detection device, 31b ... use side pressure detection device, 32 ... control device.

Claims (1)

(57) [Claims] 1. A heat source side refrigerant cycle in which a compressor, a heat source side heat exchanger, a pressure reducing device and a first auxiliary heat exchanger are connected in a ring shape, and a heat cycle formed integrally with the first auxiliary heat exchanger. A use-side refrigerant cycle having a second auxiliary heat exchanger to be exchanged, a refrigerant transfer device, and a plurality of use-side heat exchangers; a heat-source-side pressure detection device that detects a refrigerant pressure of the heat-source-side refrigerant cycle; A multi-room air-conditioning / heating apparatus comprising: a use-side pressure detection device that detects a refrigerant pressure in a cycle; and a refrigerant leakage detection device that detects refrigerant leakage in the use-side refrigerant cycle based on a pressure difference detected by the two pressure detection devices.