JPS6217144B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump device having a defrosting mechanism for removing frost attached to a heat exchanger.

Conventionally, when defrosting heat pump equipment,
For example, hot gas defrosting as shown in FIG. 1 was used. In Figure 1, 1 is a compressor, 2 is a water heat exchanger, 3 is a receiver, 4A, 4B, 4C are air heat exchangers, 5A, 5B, 5C are on-off valves such as solenoid valves, 6A, 6B, 6C are expansion valves, 7A, 7B,
7C is a throttle valve, and 8A, 8B, and 8C are on-off valves such as electromagnetic valves. 9A, 9B, 9C are temperature detectors that detect the temperature of refrigerant gas, 10A, 10B, 10
A pressure detector C detects the pressure of the refrigerant gas, and controls the expansion valves 6A, 6B, and 6C so that the pressure and temperature fall within a predetermined relationship range. 11 is a suction line, 12 is a discharge line, and a bypass pipe 13 branched from a part of the discharge line 12 is
They are connected to air heat exchangers 4A, 4B, and 4C via on-off valves 14A, 14B, and 14C, such as electromagnetic valves, respectively.

When defrosting the air heat exchangers 4A, 4B, and 4C in such a heat pump device, first, for example, in order to defrost the air heat exchanger 4A, the on-off valves 5A and 8A are closed, and the on-off valve 14A is closed. The hot gas is opened and guided into the air heat exchanger 4A through the bypass pipe 13, and its latent heat is used for defrosting.The hot gas condenses to become a refrigerant liquid, passes through the throttle valves 7A and 7C, and is discharged from the expansion valves 6B and 6C. It joins with the refrigerant liquid, enters the air heat exchangers 4B and 4C, evaporates, enters the suction line 11, and is sucked into the compressor 1.

In such a conventional example, the hot gas is directly used for defrosting in the air heat exchangers 4A, 4B, 4.
C, the temperature is high (for example, 90 for R22).
~100℃) High pressure (e.g. 15~18ata) gas gives a thermal shock to the low temperature air heat exchangers 4A, 4B, 4C and various parts of the refrigerant piping, causing damage to the piping and valve gaskets, temperature detectors 9A, 9B, 9C, pressure detector 1
There was a drawback that overload was applied to 0A, 10B, and 10C (especially the diaphragm), leading to breakage and damage.

The present invention eliminates the above-mentioned drawbacks of the conventional method by using the intermediate pressure gas in the intermediate stage of the compressor as the defrosting gas, and defrosting is performed with a refrigerant gas having a relatively low temperature and low pressure. is possible,
The object of the present invention is to provide a heat pump device that can prevent troubles such as damage to various parts.

The present invention will be explained with reference to the drawings based on examples.
In FIG. 2, parts with the same symbols as in FIG. 1 have the same configuration and functions as those in FIG. 1. 15 is an intermediate pressure bypass connected to the intermediate discharge port 16 of the compressor 1, and is equipped with a pressure regulating valve 17, and an on-off valve 14.
They are connected to air heat exchangers 4A, 4B, and 4C via A, 14B, and 14C, respectively. 18A, 1
8B, 18C are check valves, 19A, 19B, 1
9C is an on-off valve such as a solenoid valve.

For defrosting, for example, when defrosting the air heat exchanger 4A, the on-off valves 5A and 8A are closed, the on-off valve 14A is opened, the pressure regulating valve 17 is opened to an appropriate opening degree, and the compressor 1 is Defrosting is performed by introducing the intermediate pressure gas from the intermediate pressure outlet 16 into the air heat exchanger 4A.

Since the intermediate pressure gas has a temperature of about 20 to 50°C and a pressure of about 5 to 10 ata, it does not apply thermal shock to each part during defrosting, and damage can be prevented.

When condensed liquid accumulates in the air heat exchanger 4A, if the on-off valve 5B is closed and the on-off valve 19A is opened, the condensed liquid enters the air heat exchanger 4B through the expansion valve 6B and evaporates into refrigerant gas. It is sucked into the compressor 1.

In this way, the on-off valves 5A, 5B, 5C, 8A, 8
B, 8C, 14A, 14B, 14C, 19A, 1
By controlling the opening and closing of the air heat exchangers 9B, 19C and the pressure regulating valve 17, the air heat exchangers 4A, 4B, and 4C are defrosted sequentially (in any order).

FIG. 3 shows an example of control of each valve when defrosting is performed in the order of air heat exchangers 4A, 4B, and 4C.

Defrosting can be carried out on two air heat exchangers (e.g. 4 air heat exchangers) at a time.
A and 4B) may be carried out by introducing an intermediate pressure gas into them. Further, the number of air heat exchangers may be two or more, and any number of the air heat exchangers may be used.

An on-off valve may be used instead of the pressure regulating valve 17, but by using the pressure regulating valve 17, the air heat exchanger (4B next to 4A in the above example) that evaporates the refrigerant condensed after defrosting The driving force for feeding the condensed refrigerant can be adjusted, and the flow rate of the intermediate pressure gas can be controlled to prevent the amount of high pressure discharged gas going to the water heat exchanger 2 from decreasing.

According to the present invention, defrosting can be performed using gas at medium temperature and medium pressure, so it is possible to provide a heat pump device that alleviates thermal shock and prevents damage to various parts, and has extremely large practical effects. .

[Brief explanation of the drawing]

FIG. 1 is a flowchart of a conventional example, FIG. 2 is a flowchart of an embodiment of the present invention, and FIG. 3 is a diagram showing an example of control of each valve during defrosting. 1... Compressor, 2... Water heat exchanger, 3... Receiver, 4A, 4B, 4C... Air heat exchanger, 5
A, 5B, 5C...Open/close valve, 6A, 6B, 6C...
...Expansion valve, 7A, 7B, 7C... Throttle valve, 8A,
8B, 8C...Opening/closing valve, 9A, 9B, 9C...Temperature detector, 10A, 10B, 10C...Pressure detector, 11...Suction line, 12...Discharge line,
13...Bypass pipe, 14A, 14B, 14C...
...Opening/closing valve, 15...Intermediate pressure bypass, 16...Intermediate pressure outlet, 17...Pressure regulating valve, 18A, 18
B, 18C...Check valve, 19A, 19B, 1
9C...Opening/closing valve.

Claims (1)

[Scope of Claims] 1. In a heat pump device equipped with a compressor, a water heat exchanger, and a plurality of air heat exchangers, a discharge port is provided in the middle of the compression process of the compressor to bypass the plurality of air heat exchangers. 2. A heat pump device, characterized in that the heat pump device is connected to the air heat exchanger to be defrosted, and at the time of defrosting, a part of the gas in the middle of the compression process of the compressor is guided through the bypass to the air heat exchanger to be defrosted. 2. The device according to claim 1, wherein the bypass is provided with a pressure regulating valve.