JPS6217145B2 - - 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 refrigerant gas, and controls the expansion valves 6A, 6B, and 6C so that the pressure and detection 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.

In such a heat pump device, when defrosting the air heat exchangers 4A, 4B, and 4C, 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 opened. , the hot gas is transferred from the bypass pipe 13 to the air heat exchanger 4A.
The hot gas condenses into refrigerant liquid, passes through throttle valves 7A and 7C, and joins with refrigerant liquid from expansion valves 6B and 6C to air heat exchangers 4B and 4C. It evaporates and enters the suction line 11 where it 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 to 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 (particularly the diaphragm), leading to breakage and damage. In addition, before reaching the water heat exchanger 2, a part of the discharged gas is bypassed for defrosting, so the water heat exchanger 2
The condensing pressure in the air heat exchanger 4A,
A liquid flash occurs in the refrigerant liquid sending pipe to 4B or 4C, leading to a decrease in the capacity of the expansion valve 6A, 6B or 6C, resulting in a decrease in heating capacity and an air heat exchanger that has not been defrosted (in the above example, 4B , 4C) had the disadvantage of increasing frost formation.

By providing an economizer and using economizer gas as a defrosting gas, the present invention eliminates the above-mentioned drawbacks of the conventional ones and can defrost with a refrigerant gas having a relatively low temperature and low pressure. The object of the present invention is to provide a heat pump device that can prevent problems such as damage to various parts, a decrease in heating capacity, and an increase in frost formation.

The present invention will be explained with reference to the drawings based on examples.
In FIG. 2, parts having the same symbols as those in FIG. 1 have the same configuration and functions as those in FIG. An economizer 15 is provided in the middle of the refrigerant path between the water heat exchanger 2 and the air heat exchangers 4A, 4B, and 4C.
17, connected via an on-off valve 18. Furthermore, a bypass pipe 20 having a pressure regulating valve 19 is branched from the bypass pipe 16, and the on-off valves 14A, 14
B, 14C via air heat exchangers 4A and 14C, respectively.
Connected to 4B and 4C.

For defrosting, for example, when defrosting the air heat exchanger 4A, the on-off valves 5A, 8A, and 18 are closed, the on-off valve 14A is opened, the pressure regulating valve 19 is opened to an appropriate degree, and the economizer is Defrosting is performed by guiding the gas into the air heat exchanger 4A. Since this economizer gas has a temperature of about 15 to 25° C. and a pressure of about 6 to 10 ata, it does not apply thermal shock to various parts during defrosting, and can prevent damage.

The condensed refrigerant liquid joins the refrigerant liquid from the expansion valve 6B or 6C via the throttle valve 7A or 7C,
The air enters the air heat exchanger 4B or 4C, evaporates, and is sucked into the compressor 1. Similarly, air heat exchanger 4
Defrost B 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 economizer gas. Alternatively, defrosting may be performed using part of the economizer gas without fully closing the on-off valve 18. The number of air heat exchangers may be two or more, and any number of air heat exchangers may be used.

An on-off valve may be used instead of the pressure regulating valve 19, but by using the pressure regulating valve 19, the economizer 15 can maintain a certain level of pressure (when the on-off valve 18 is fully closed, the intermediate pressure Since the pressure is no longer regulated by the stages, the low pressure of other air heat exchangers causes a pressure drop, and the economizer 15
), economizer 15
can prevent flashing.

Although a flash economizer may be used as the economizer 15, if a closed economizer is used, entrainment of liquid due to violent boiling can be relatively easily prevented.

According to the present invention, defrosting can be performed using saturated gas at medium temperature and pressure, so there is less thermal shock to various parts, and
Since the discharged gas is not used for defrosting, it is possible to provide a heat pump device that can prevent a decrease in performance due to a decrease in discharge pressure during defrosting, and has an extremely large practical effect.

[Brief explanation of the drawing]

FIG. 1 is a flow diagram of a conventional example, and FIG. 2 is a flow diagram of an embodiment of the present invention. 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...
...On-off valve, 15...Economizer, 16...Bypass pipe, 17...Bypass pipe, 18...On-off valve,
19...Pressure regulating valve, 20...Bypass pipe.

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, an economizer is provided in the middle of a refrigerant path between the water heat exchanger and the air heat exchanger. and at least a part of the refrigerant gas generated in the economizer is used during defrosting.
A heat pump device comprising a refrigerant distribution mechanism that distributes a refrigerant to an air heat exchanger to be defrosted. 2. The apparatus according to claim 1, wherein the refrigerant distribution mechanism is configured to cut off a supply path of refrigerant gas to an intermediate pressure stage of the compressor during defrosting. 3. The apparatus according to claim 1, wherein the refrigerant distribution mechanism has a pressure adjustment mechanism that adjusts the pressure of the refrigerant gas distributed to the air heat exchanger. 4. The device according to claim 1, wherein the economizer is a flash economizer. 5. The apparatus of claim 1, wherein the economizer is a closed economizer.