JPH04263752A - Air conditioner - Google Patents

Abstract

PURPOSE:To prevent a phenomenon that liquid returns to a compressor and high pressure cut during heating operation by a method wherein a solenoid valve is provided in a branch pipe of a water side heat exchanger, and when, for example, shell temperature of the compressor during cooling operation goes down below a prescribed value, the solenoid valve is closed. CONSTITUTION:Gas refrigerant of high temperature and high pressure discharged from a compressor 1 during cooling operation passes through a four-way turnover valve 2, is heat-exchanged at a water side heat exchanger 5 with circulating water from a water passage 15, and condensed and liquefied. The thus liquefied refrigerant is heat-exchanged at an indoor heat exchanger 5 with room air from a fan 6 and vaporized and gasified, and then, returned to the compressor 1 through the four-way turnover valve 2. At this time, shell temperature of the compressor 1 is detected by a temperature detecting means 11. If the detected temperature goes down below a prescribed value, a solenoid valve 9 mounted on a branch pipe 7 of the water side heat exchanger 3 is closed. By this, liquid refrigerant is stored in the closed water side heat exchanger 3, and the quantity of refrigerant circulating through a refrigeration cycle is reduced, and further liquid return phenomenon of unvaporized liquid refrigerant to the compressor 1 is prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an air conditioner that performs heating and cooling by preventing liquid back during cooling and overload during heating.

0002

2. Description of the Related Art The configuration of a refrigeration cycle of a conventional air conditioner is shown in FIG. In FIG. 2, 1 is a compressor, 2 is a four-way switching valve, 3 is a water side heat exchanger, 4 is a pressure reducing device, and 5 is an air side heat exchanger, and by connecting these in order with refrigerant piping 16, A refrigeration cycle is configured. Also, 6
15 is an air blower that sends air to the air side heat exchanger 5, and 15 is a water circuit that sends water to the water side heat exchanger 3.

Next, the operation will be explained. During cooling operation (
(The flow of the refrigerant is indicated by the thick solid line arrow in the figure), the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way switching valve 2, and is sent to the water side heat exchanger 3 by the water circuit 15. After exchanging heat with circulating water and condensing and liquefying the gas refrigerant, it is depressurized by the pressure reducing device 4 and becomes a low-temperature, low-pressure liquid refrigerant.

[0004] After that, this liquid refrigerant enters the indoor heat exchanger 5 and exchanges heat with the indoor air blown by the blower 6.
In addition to cooling the indoor air, the liquid refrigerant is evaporated and gasified, passes through the four-way switching valve 2, and returns to the compressor 1, forming a refrigeration cycle during cooling. From then on, the refrigerant passes through the above-mentioned refrigeration cycle path. It is circulated through repeated liquefaction and vaporization.

On the other hand, during heating operation (the flow of the refrigerant is indicated by the dashed arrow in the figure), the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way switching valve 2, which is switched to the heating side. The gas refrigerant enters the air-side heat exchanger 5 and exchanges heat with the indoor air blown by the blower 6 to heat the indoor air, and thereby condenses and liquefies the gas refrigerant.

[0006] This liquid refrigerant is depressurized by a pressure reducing device 4, and becomes a low-temperature, low-pressure liquid refrigerant. After that, the liquid refrigerant enters the water side heat exchanger 3, exchanges heat with the circulating water sent by the water circuit 15, reheats from the circulating water, and cools the circulating water.
As a result, the liquid refrigerant is evaporated and gasified, passes through the four-way switching valve 2, and returns to the compressor 1, thereby forming a refrigeration cycle during heating.

[0007]

[Problems to be Solved by the Invention] Since the conventional air conditioner is configured as described above, the amount of air blown to the air side heat exchanger 5 by the blower 6 during cooling is controlled by the air filter (not shown). ), if the indoor temperature becomes low, or if the temperature of the circulating water sent by the water circuit 15 becomes low, the evaporation pressure will decrease and the evaporation capacity will decrease. The liquid refrigerant in the air-side heat exchanger 5 could not be completely evaporated and gasified, and the liquid refrigerant returned to the compressor 1, causing the compressor 1 to compress the liquid, resulting in compressor trouble.

Furthermore, during heating, when the temperature of the circulating water fed by the water circuit 15 becomes high, the high pressure of the liquid refrigerant increases, causing problems such as abnormal stoppage due to high pressure cut.

[0009] This invention was made to solve the above-mentioned problems, and there is no liquid returning to the compressor during cooling operation, and high pressure increases during heating operation, resulting in abnormality due to high pressure cut. The purpose is to provide an air conditioner that never stops.

0010

[Means for Solving the Problems] The air conditioner according to the present invention includes temperature detection means provided at the water pipe outlet and the compressor shell, and one of the plurality of distribution pipes in the water side heat exchanger. The solenoid valve is provided with a bidirectional solenoid valve that closes when the compressor shell temperature falls below a predetermined temperature during cooling operation, and closes when the outlet water temperature rises above a predetermined temperature during heating operation.

[0011]

[Operation] In this invention, during cooling operation, the compressor shell temperature is detected by the temperature detection means, and one of the plurality of distribution pipes in the water side heat exchanger is blocked by a solenoid valve, so that the liquid refrigerant is blocked. The amount of refrigerant that accumulates in the heat exchanger and circulates through the refrigeration cycle is reduced, and during heating operation, the outlet water temperature of the water circuit is detected by the temperature detection means, and one of the multiple distribution pipes in the water side heat exchanger is It is closed by a solenoid valve to maintain the evaporation capacity below a predetermined amount and prevent high pressure cuts due to high pressure increases.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the air conditioner according to the present invention will be described below with reference to the drawings. FIG. 1 is a refrigerant circuit diagram of one embodiment. In FIG. 1, parts that are the same as those in FIG. 2 are designated by the same reference numerals to avoid redundant explanation, and the parts different from those in FIG. 2 will be mainly described.

As is clear from comparing FIG. 1 with FIG. 2, the parts indicated by numerals 1 to 8, 15, and 16 are the same as in FIG. 2, and in this FIG. 9,10,
The part indicated by 11 has been added.

That is, 9 is the distribution pipe 7 of the water side heat exchanger 3.
This is a bidirectional solenoid valve installed in one of the Also, 1
0 is a temperature detecting means for detecting the outlet temperature of the circulating water of the water circuit 15, and 11 is a temperature converting means for detecting the shell temperature of the compressor 1. The other configurations are the same as in FIG. 2.

Next, the operation will be explained. First, we will discuss the case of cooling operation. During cooling operation (the flow of refrigerant is indicated by thick solid line arrows in the figure), the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way switching valve 2 and is sent to the water-side heat exchanger 3 by the water channel 15. The gas refrigerant condenses and liquefies by exchanging heat with the circulating water.

Next, this condensed and liquefied gas refrigerant is
The refrigerant passes through the electromagnetic valve 9 and the distribution pipe 8 and is depressurized by the pressure reducing device 4, becoming a low-temperature liquid refrigerant.

After that, this liquid refrigerant enters the indoor heat exchanger 5 and exchanges heat with the indoor air blown by the blower 6.
In addition to cooling the indoor air, a refrigeration cycle during cooling is constructed in which the liquid refrigerant is evaporated and gasified, passes through the four-way switching valve 2, and returns to the compressor 1. From then on, the refrigerant passes through the above-mentioned refrigeration cycle path. It is circulated through repeated liquefaction and vaporization.

Note that the air side heat exchanger 5 is
If the amount of air blown to the air filter decreases due to dirt on the air filter, or if the indoor temperature decreases, or if the temperature of the circulating water sent by the water circuit 15 decreases, the evaporation pressure will decrease. , since the evaporation capacity decreases, unevaporated liquid refrigerant returns to the compressor 1.

[0019] Therefore, when the compressor 1 falls
When the shell temperature of the water side heat exchanger 3 is detected by the shell temperature detection means 11 and becomes below a predetermined temperature (20°C or below), the water side heat exchanger 3
The solenoid valve 9 attached to the distribution pipe 7 is closed so that the liquid refrigerant accumulates in the closed water side heat exchanger 3. and,
The amount of refrigerant circulating through the refrigeration cycle is reduced to prevent unevaporated liquid refrigerant from returning to the compressor 1.

On the other hand, during heating operation (the flow of the refrigerant is indicated by the dashed arrow in the figure), the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way switching valve 2, which is switched to the heating side. The gas refrigerant enters the air-side heat exchanger 5 and exchanges heat with the indoor air blown by the blower 6 to heat the indoor air, and thereby condenses and liquefies the gas refrigerant. This liquid refrigerant is depressurized by the pressure reducing device 4 and becomes a low-temperature, low-pressure liquid refrigerant.

After that, the liquid refrigerant flows through the distribution pipe 8 and the solenoid valve 9.
The refrigerant enters the water-side heat exchanger 3 through the water circuit 15, exchanges heat with the circulating water sent by the water circuit 15, reheats the circulating water, cools the circulating water, and evaporates the liquid refrigerant into gas.
It passes through the four-way switching valve 2 and returns to the compressor 1. In this way, a refrigeration cycle for heating is configured.

[0022] If the temperature of the circulating water fed by the water circuit 15 increases, the evaporation capacity of the liquid refrigerant increases, the high pressure of the liquid refrigerant increases, and problems such as abnormal stoppage due to high pressure cut occur. Therefore, the water temperature detection means 10 attached to the water circuit 15 detects the outlet temperature of the circulating water, closes the solenoid valve 9 attached to the distribution pipe 7 of the water side heat exchanger 3, and removes the water side heat. One circuit of the exchanger 3 is prevented from exchanging heat. This reduces the evaporation capacity of the liquid refrigerant and maintains the high pressure within a predetermined usage range.

[0023]

As explained above, according to the present invention, a solenoid valve is provided in one of the plurality of distributions in the water side heat exchanger, and a temperature detection means is provided at the outlet of the water pipe and the compressor shell. When the compressor shell temperature falls below a predetermined temperature during cooling operation, the solenoid valve is closed, and when the outlet water temperature rises above a predetermined temperature during heating operation, the solenoid valve is closed. This has the effect of preventing liquid from returning to the compressor and preventing high pressure cuts during heating operation.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant circuit diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram of a conventional air conditioner.

[Explanation of symbols]

1 Compressor 2 Four-way switching valve 3 Water side heat exchanger 4 Squeezing device 5 Air side heat exchanger 6 Indoor blower 7, 8 Distributor 9 Solenoid valve 10, 11 Temperature conversion means 15 Water circuit 16 Refrigerant piping

Claims (1)

[Claims] [Claim 1] Compressor, four-way switching valve, water side heat exchanger,
a refrigeration cycle formed by sequentially connecting a pressure reducing device and an air side heat exchanger with refrigerant piping; a first temperature exchange means for exchanging the temperature at the outlet of the water piping that supplies water to the water side heat exchanger; A second temperature exchanging means for detecting the temperature of the shell portion of the machine and one of the plurality of distributors in the water side heat exchanger is provided, and the temperature is detected by the second temperature detecting means during cooling operation. and a solenoid valve that closes when the shell temperature of the compressor falls below a predetermined temperature and when the outlet water temperature of the water pipe detected by the first temperature detection means during heating operation becomes above a predetermined temperature. Air conditioner.