JPS5929955A - Refrigeration cycle device for air conditioner with refrigerant heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an improvement in the refrigeration cycle of an air conditioner equipped with a refrigerant heater that improves the heating capacity at low outside temperatures. The present invention provides a refrigeration cycle device that prevents liquid from returning to the machine.

Conventional configuration and its problems A conventional refrigeration cycle of this type is configured as shown in FIG.

In the figure, 1 is a compressor, 2 is a four-way switching valve, 3 is an indoor heat exchanger, 4 is a pressure reduction mechanism, 5 is an outdoor heat exchanger, and 6 is a refrigerant that heats the return pipe to the compressor 1. This refrigerant heater 6 includes a heat medium 6a such as water, a heat source 6b for heating the heat medium 6a, and the like. 7.
8 is an electromagnetic on-off valve that controls the flow of the refrigeration cycle. Reference numeral 9 denotes an on-off valve that controls communication between the discharge side and the suction side of the compressor 1. Reference numeral 10 denotes a receiver for storing refrigerant, which is provided between the on-off valve 9, the branch part on the suction side, and the heater 6.
It is. These are connected in an annular manner as shown in the figure to constitute an annular refrigeration cycle.

The main purpose of this refrigeration cycle is to prevent the liquid from returning to the compressor 1, but in this refrigeration cycle, even when liquid is not returning, it always passes through the receiver 1o, so there is a pressure loss in the refrigerant. There was a problem in that the space became large, reducing the heating capacity, and the space in the storage section of the cash register (-10) had to be large, which was disadvantageous in terms of cost.

OBJECTS OF THE INVENTION The present invention eliminates these conventional drawbacks, enables effective heating operation with a stable refrigeration cycle, and makes it possible to reduce the space of the refrigeration cycle housing.

Structure of the Invention In order to achieve the above object, a refrigeration cycle device for an air conditioner equipped with a refrigerant heater according to the present invention connects a compressor, an indoor heat exchanger, and a refrigerant heater that heats a refrigerant in an annular manner. A refrigeration cycle is constructed by connecting an on-off valve that bypasses the high-pressure side piping and the low-pressure side piping of the compressor, and a thermistor for detecting the temperature of the refrigerant is provided at the outlet of the refrigerant heater of this refrigeration cycle, and The piping connecting the heat exchanger and the refrigerant heater is provided with an on-off valve that opens when the thermistor detects a temperature higher than a predetermined temperature, and a pressure reducing mechanism is provided in parallel with this on-off valve. This is a characteristic feature.

DESCRIPTION OF EMBODIMENTS Hereinafter, the present invention will be described with reference to FIG. 2 regarding a refrigeration cycle device for an air conditioner with a refrigerant heater, which shows one embodiment of the present invention. In this embodiment, the same members as in FIG. 1 are designated by the same numbers. In Fig. 2, 1 is a compressor, 2 is a four-way switching valve, 3 is an indoor heat exchanger, 4 and 12 are pressure reducing mechanisms, and 6
6 is an outdoor heat exchanger, 6 is a refrigerant heater that heats the return pipe to the compressor, and this refrigerant heater 6 includes a heat medium 6a such as water and a heating device that heats the heat medium 6a. A source 6b etc. are provided. 7, 8, and 11 are electromagnetic on-off valves that control the flow of the refrigeration cycle. 9 is an on-off valve that controls communication between the discharge side and the suction side of the compressor 1. By connecting these in a ring as shown in FIG. 2, a ring-shaped refrigeration cycle is constructed. Furthermore, by attaching a temperature detector such as a thermistor to the outlet C point of the refrigerant heater 6, the degree of heating of the refrigerant is detected.

In the above configuration, during cooling operation, the refrigerant discharged from the compressor 1 is transferred to the four-way switching valve 2, the outdoor heat exchanger 6, the pressure reducing mechanism 4, the on-off valve 8, and the indoor heat exchanger 3 as shown by the broken line arrow.
, passes through a four-way switching valve 2, and returns to the compressor 1, forming a refrigeration cycle.

Note that in this case, since the on-off valve 7 is closed, no refrigerant flows into the refrigerant heater 6. Since the on-off valve 9 is also closed, there is no bypass from the high pressure pipe side to the low pressure pipe side. In addition, during heating operation using a normal heat pump system, the refrigerant discharged from the compressor 1 is transferred to the four-way switching valve 2, as shown by the solid arrow.
A refrigeration cycle is configured in which the air passes through the indoor heat exchanger 3, the on-off valve 8, the pressure reducing mechanism 4, the outdoor heat exchanger 6, and the four-way switching valve 2 and returns to the compressor 1. Note that in this case as well, the on-off valve 7.9 is closed as in the cooling operation.

Next, when performing a refrigerant heating operation using the refrigerant heater 6,
When the temperature at the outlet point C of the refrigerant heater 6 is below a certain set value, that is, when the refrigerant coming out of the refrigerant heater 6 is a liquid or a two-phase liquid, the refrigerant is transferred to the compressor 1 as shown by the chain arrow.
, a four-way switching valve 2, an indoor heat exchanger 3, an on-off valve 7, a pressure reducing mechanism 12, the refrigerant is liquefied into two phases, and enters a refrigerant heater 6, where it is completely evaporated and sent to a compressor 1. This constitutes a refrigeration cycle.

In this refrigerant heater operation, the refrigerant does not pass through the outdoor heat exchanger 6 because the on-off valve 8 is closed. Moreover, the on-off valve 11 is also closed by the temperature detection of the thermistor at the outlet point C of the refrigerant heater 6.

Next, when performing a refrigerant heating operation using the refrigerant heater 6,
When the temperature at the outlet point C of the refrigerant heater 6 is above a certain set value, that is, when the refrigerant coming out of the refrigerant heater 6 is in a gaseous state, the refrigerant is transferred to the compressor 1 and the four-way switching valve as shown by the two-dot chain arrow. 2. A refrigeration cycle is constructed in which the refrigerant passes through the indoor heat exchanger 3 and the on-off valves 7 and 11, enters the refrigerant heater 6, and returns to the compressor 1.

Also in this case, since the on-off valve 8 is closed for the refrigerant heating operation, the outdoor heat exchanger 6 does not pass through. In addition, the on-off valve 11 is detected by the thermistor temperature at the outlet C point of the refrigerant heater 6.
Therefore, there is no pressure difference between the inlet point of the pressure reducing mechanism 120 and the outlet point E, and the refrigerant flows through the on-off valve 11 without passing through the pressure reducing mechanism 12. In other words, the refrigerant heating operation using the refrigerant heaters etc. The discharge side and suction side of the compressor 1 are connected, and a part of the refrigerant in the refrigeration cycle is bypassed to adjust the flow rate of the refrigerant flowing to the indoor heat exchanger 3 and the refrigerant heater 6. When the compressor 1 is operated while the heating source 6b is stopped or the amount of heating is adjusted, the amount of heating given to the refrigerant flowing through the refrigerant heater 6 decreases. Therefore, in the refrigerant heater 6, the amount of refrigerant circulated and the amount of heating cannot be balanced, so the refrigerant that comes out of the outlet of the refrigerant heater 6 is not in a completely gasified state but is mixed with some liquid refrigerant and reaches the compressor. 1, the refrigerant passes through the control valve 9 and joins the bypassed refrigerant. At this time, since there is a large temperature difference between the partially liquid refrigerant that has exited the refrigerant heater 6 and the refrigerant that has been gasified through the control valve 9, some of the liquid refrigerant is gasified, causing a bubbling phenomenon. When bubbles flow into the compressor 1, the oil in the compressor 1 flows out to the discharge side, and the oil is not circulated to the sliding parts of the compressor 1, causing mechanical wear and damage to the compressor. Damage 1. Further, although a receiver is usually provided between the suction side of the compressor 1 and the bypass branch, a large-capacity receiver is required to prevent the above-mentioned bubbles from flowing into the compressor 1. . Moreover, when a receiver with this large capacity is attached, the pressure loss of the refrigerant becomes large and the heating capacity decreases.

Therefore, when the compressor 1 is operated in a refrigerant heating operation with the heat source 6b stopped or the heating amount adjusted, the refrigerant temperature at the outlet C point of the refrigerant heater 6 is detected by a thermistor or the like. When the temperature is below a certain set value, that is, when the refrigerant is liquid or partially liquid, the on-off valve 11
is closed and the refrigerant is made into a two-phase liquid through the pressure reduction mechanism 12,
The refrigerant is completely gasified in the refrigerant heater 6 and returned to the compressor 1. Also, if the temperature at the 0 point is higher than a certain set value,
That is, when the refrigerant is gasified, the on-off valve 11 is opened to allow the refrigerant to flow. This prevents damage to the compressor 1 and at the same time provides a stable refrigeration cycle.

Effects of the Invention According to the refrigeration cycle device for an air conditioner equipped with a refrigerant heater according to the present invention, the refrigerant temperature at the outlet of the refrigerant heater provides resistance to the refrigerant flowing from the indoor heat exchanger to the refrigerant heater. By selecting whether or not, it is possible to prevent liquid refrigerant from flowing into the compressor when the heating source of the refrigerant heater is stopped or the heating amount is reduced. A stable refrigeration cycle is obtained without leakage to the receiver, and
Since it only needs to be relatively small, the storage space for the refrigeration cycle can be reduced, and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram of a conventional air conditioner equipped with a refrigerant heater, and FIG. 2 is a refrigeration cycle diagram of an air conditioner equipped with a refrigerant heater according to an embodiment of the present invention. 1...Compressor, 3...Indoor heat exchanger, 6...Refrigerant heater, 9, 11...Opening/closing valve, 12... ...Decompression mechanism. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 4 Figure 2

Claims (1)

[Claims] A compressor, an indoor heat exchanger, a refrigerant heater that heats the refrigerant, and the compressor are connected in a ring, and an on-off valve that bypasses the high-pressure side piping and low-pressure side piping of the compressor is connected to form a refrigeration cycle. A thermistor for detecting the temperature of the refrigerant is provided at the outlet of the refrigerant heater of the refrigeration cycle, and the thermistor detects a temperature equal to or higher than a predetermined temperature in a pipe connecting the indoor heat exchanger and the refrigerant heater. A refrigeration cycle device for an air conditioner that is equipped with a refrigerant heater that is provided with an on-off valve that opens at times and a pressure reducing mechanism in parallel with this on-off valve.