JPH0311250A - Multi-room air-conditioning equipment - Google Patents

Abstract

PURPOSE:To quickly and surely allow the multi-room air-conditioning equipment to detect refrigerant leakage to prevent an air-conditioning capacity from rapidly being lowered to protect a refrigerant conveyance device from being damaged by separating a heat source side refrigerating cycle and a utilization side refrigerating cycle each other to detect a degree of superheat so as to detect refrigerant leakage of the utilization side refrigerating cycle with the use of the degree of superheat. CONSTITUTION:During air-conditioning operation, the capacities of a heat source side refrigerating cycle and a refrigerant conveyance device 21 are controlled so that a degree of superheat in a second auxiliary heat exchanger 19 of a utilization side refrigerating cycle may be a specified one. In the case where a refrigerant of the utilization side refrigerant cycle is leaked, a quantity of the refrigerant circulating in the utilization side refrigerating cycle reduces, so that the refrigerant may be superheated by utilization side heat exchangers 22a, 22b to superheat higher than the degree of superheat at the time of optimum in the inlet of the second auxiliary heat exchanger 19. The degree of the superheat is detected by a degree-of-superheat detector 30 to detect refrigerant leakage of the utilization side refrigerating cycle by a refrigerant leakage detector 31 with the use of the detected degree of superheat.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the refrigerant cycle of a multi-room air-conditioning system.
This relates to refrigerant leak detection.

2. Description of the Related Art Conventionally, the refrigerant cycle of a multi-room air conditioning system is separated into a heat source side refrigerant cycle and a user side refrigerant cycle, and heat is exchanged between the two using an auxiliary heat exchanger.
1 is a compressor, 12 is a four-way valve, 13 is a heat source side heat exchanger, 1
4 is a pressure reducing device for cooling, 15 is a pressure reducing device for heating, 16 is a check valve that closes the cooling pressure reducing device 14 during heating, 17 is a check valve that closes the heating pressure reducing device 15 during cooling, and 18 is a check valve that closes the heating pressure reducing device 15 during cooling. These are connected in an annular manner by the first auxiliary heat exchanger to form a heat source side refrigerant cycle. 19 is the second auxiliary heat exchanger
It is integrally formed to exchange heat with the auxiliary heat exchanger 18. 20 is a refrigerant amount adjustment tank that adjusts the amount of refrigerant during cooling and heating. Reference numeral 21 denotes a refrigerant conveying device which has a reversible characteristic such that the outflow direction of the refrigerant is opposite during cooling and heating, and is housed in the outdoor unit f. 22a,
Reference numeral 22b denotes a user-side heat exchanger, which is housed in the indoor unit gyh and connected to the outdoor unit f through connection piping 1+l'+j+J'. The second auxiliary heat exchanger 19 and the refrigerant amount adjustment tank 20. Refrigerant conveyance device 21. Utilization side heat exchangers 22a, 22b and connection piping 1°1'
+J+j'' are connected in an annular manner to form a user-side refrigerant cycle.

The operation of the multi-room heating and cooling system configured as described above will be explained.

During cooling operation, the refrigerant cycle is indicated by the solid line in the figure. In the heat source side refrigerant cycle, high temperature, high pressure gas from the compressor 11 passes through the four-way valve 12, radiates heat in the heat source side heat exchanger 13, condenses and liquefies, and closes the check valve 16. The air is then depressurized in the cooling pressure reducing device 14, evaporated in the first auxiliary heat exchanger 18, and circulated through the four-way valve 12 to the compressor 11. At this time, the second refrigerant cycle of the user side
The auxiliary heat exchanger 19 and the first auxiliary heat exchanger 18 exchange heat, and the gas refrigerant in the user-side refrigerant cycle is cooled and liquefied, and is sent to the refrigerant conveying device 21 through the refrigerant amount adjustment tank 20. The refrigerant is sent to the user-side heat exchangers 22a and 22b through the connection pipes l and j by the refrigerant conveyance device 21, where it is endothermically evaporated, gasified, and circulated through the connection pipes 1'+J' to the second auxiliary heat exchanger 19. ＼I will do it.

On the other hand, during heating operation, the refrigerant cycle is as shown by the broken line in the figure, and in the heat source side refrigerant cycle, the high temperature and high pressure refrigerant from the compressor 11 is transferred from the four-way valve 12 to the first auxiliary heat exchanger 18.
It radiates heat, condenses and liquefies, reduces the pressure through the check valve 17 in the heating pressure reducing device 15, absorbs heat and evaporates in the heat source side heat exchanger 13, and circulates through the four-way valve 12 to the compressor 11. At this time, the second auxiliary heat exchanger 19 of the user side refrigerant cycle and the first
The auxiliary heat exchanger 18 exchanges heat, and the refrigerant in the user-side refrigerant cycle is heated and gasified, and is sent to the user-side heat exchangers 22a and 22b through the connecting pipe 1'j', where it is heated and heat-radiated into liquid. The refrigerant conveying device 21 passes through the connecting pipe 1+J.
The refrigerant is sent to the refrigerant amount adjustment tank 20 and circulated to the second auxiliary heat exchanger 19.

Problems to be Solved by the Invention However, with the above configuration, if the refrigerant in the user-side refrigerant cycle gradually leaks, it will not affect the indoor unit's performance to a certain extent, but at some point the refrigerant transport device will start to leak. A large amount of gas refrigerant is now inhaled,
Since the amount of refrigerant circulation is extremely reduced, the capacity of the indoor unit is rapidly reduced, and there is a risk that the refrigerant transport device may be damaged due to poor lubrication of the refrigerant transport device.

In view of the above-mentioned problems, the present invention provides a multi-room air-conditioning system that detects refrigerant leakage in a user-side refrigerant cycle with a simple configuration and is free from damage to a refrigerant transport device due to refrigerant leakage.

Means for Solving the Problems In order to solve the above problems, the multi-room air conditioning system of the present invention separates the heat source side refrigerant cycle and the usage side refrigerant cycle, and adjusts the degree of superheating of the refrigerant in the second auxiliary heat exchanger. The refrigerant leakage detection device includes a superheating degree detection device that detects the superheating degree, and a refrigerant leakage detection device that detects refrigerant leakage from the user-side refrigerant cycle based on the superheating degree detected by the superheating degree detection device.

Function: With the above-described configuration, the present invention controls the degree of superheating of the second auxiliary heat exchanger of the user-side refrigerant cycle, so that refrigerant leakage of the user-side refrigerant cycle can be detected reliably and in advance. This also simplifies the control device.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows a refrigerant cycle of a multi-room air conditioning system according to an embodiment of the present invention.

The basic configuration is the same as the conventional example shown in FIG. 2, and only the differences will be explained here. In the figure, 30 is a superheat degree detection device that detects the degree of superheat in the 2111th auxiliary heat exchanger of the utilization side refrigerant cycle, and 31 is a superheat degree detection device 30.
This is a control device that detects refrigerant leakage in the user-side refrigerant cycle based on the degree of superheat detected in the refrigerant cycle.

The operation of the heating and cooling system configured as described above will be explained.

The basic operation of the refrigeration cycle is the same as that of the conventional example, and here we will explain the difference, that is, the operation of detecting refrigerant leakage in the user-side refrigerant cycle.

During the cooling/heating operation, the capacity of the heat source side refrigerant cycle and the capacity of the refrigerant transport device 21 are controlled so that the degree of superheating in the second auxiliary heat exchanger of the user side refrigerant cycle becomes a certain constant degree of superheating.

Therefore, if the refrigerant in the user-side refrigerant cycle leaks, if the heat load on the user-side refrigerant cycle during cooling is the same, the amount of refrigerant circulating in the user-side refrigerant cycle will decrease, so the user-side heat exchanger 22a , 22b. Therefore, at the inlet of the second auxiliary heat exchanger 19, the refrigerant will be superheated to a higher degree than the optimum superheating degree, so control is performed to increase the ability of the refrigerant carrier wave W21.This control increases the usage-side coating fluid cycle. The amount of refrigerant circulating increases,
The degree of superheating of the refrigerant at the inlet of the second auxiliary heat exchanger 19 is controlled to the optimum degree of superheating, and a cooling capacity commensurate with the heat load is exhibited.

However, there are limits to the control to increase the capacity of the refrigerant transfer device 21, so if the amount of refrigerant leakage exceeds a certain level (for example, 20 to 30%), the amount of refrigerant at the inlet of the second auxiliary heat exchanger 19 will be reduced. The degree of superheating cannot be controlled to the optimum degree of superheating.

On the other hand, if the refrigerant in the user-side refrigerant cycle leaks during heating as well, the amount of refrigerant circulating in the user-side refrigerant cycle will decrease, so the second auxiliary heat exchanger 19 will filter the refrigerant to reduce the superheat level at the time of R. It will get heated.

Therefore, in order to perform control to increase the capacity of the refrigerant transport device 21 and increase the amount of refrigerant circulating in the user-side refrigerant cycle, the degree of superheating of the refrigerant at the outlet of the second auxiliary heat exchanger 19 is adjusted to the optimum level. The heating capacity is controlled according to the heat load.

However, since there is a limit to the control to increase the capacity of the refrigerant transport device 21, the amount of refrigerant leakage is limited to a certain extent (for example, 2
0 to 30%), the degree of superheating of the refrigerant at the outlet of the second auxiliary heat exchanger 19 cannot be controlled to the optimum degree of superheating.

The degree of superheating of this refrigerant is detected, and when the detected degree of superheating exceeds a certain value, that is, a large amount of gas refrigerant (non-condensing refrigerant) flows into the refrigerant conveyance device 21, and the refrigerant conveyance capacity is extremely reduced. This system displays an abnormality and forcibly stops the operation of the heating and cooling device before the cooling and heating capacity is significantly reduced and the bearing portion of the refrigerant conveyance device 21 is damaged due to lack of lubrication.

As described above, according to the present embodiment, the heat source side refrigerant cycle and the usage side refrigerant cycle are separated, and the superheat degree detection device detects the degree of superheat of the refrigerant in the second auxiliary heat exchanger, and this superheat degree Since it is equipped with a refrigerant leakage detection device that detects refrigerant leakage from the user-side refrigerant cycle based on the degree of superheat detected by the detection device, refrigerant leakage can be detected early and reliably with a simple configuration, and cooling and heating capacity can be reduced. This can prevent a sudden drop and damage to the refrigerant conveyance device.

Effects of the Invention As described above, the present invention provides a superheat degree detection device that separates a heat source side refrigerant cycle and a usage side refrigerant cycle and detects the degree of superheat of the refrigerant in a second auxiliary heat exchanger, and this superheat degree detection device. Equipped with a refrigerant leakage detection device that detects refrigerant leakage from the user-side refrigerant cycle based on the degree of superheat detected by the device, it has a simple configuration, can detect refrigerant leakage early and reliably, and can prevent sudden decreases in refrigerant transfer capacity. An extreme decrease in heating and cooling capacity due to
This has the effect of preventing damage to the bearing portion of the refrigerant conveyance device due to insufficient lubrication.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram of a multi-room air conditioning system according to an embodiment of the present invention, and FIG. 2 is a refrigeration cycle diagram of a multi-room air conditioning system that shows a conventional example. 11...Compressor, 13...Heat source side heat exchanger, 1
8...First auxiliary heat exchanger, 19...Second auxiliary heat exchanger, 21...Refrigerant conveyance device, 22a, 22b.
...Using side heat exchanger, 30...Superheat degree detection device,
31...control device.

Claims (1)

[Claims] Compressor, four-way valve, heat source side heat exchanger, pressure reducing device and first
A heat source side refrigerant cycle formed by connecting auxiliary heat exchangers in a ring shape, a second auxiliary heat exchanger formed integrally with the first auxiliary heat exchanger and exchanging heat, a refrigerant transport device, and a plurality of user side heat exchangers. a user-side refrigerant cycle having a superheat degree detection device that detects the degree of superheat of the refrigerant in the second auxiliary heat exchanger of the user-side refrigerant cycle; A multi-room air conditioning and heating system equipped with a refrigerant leakage detection device for detecting refrigerant leakage.