JPH06207751A - Heat pump fitted with oil separator - Google Patents

Abstract

PURPOSE:To enable fluoro-carbon gas which is not familiar with oil to be used in a heat pump having the present shape. CONSTITUTION:There are provide a condensor 2 and an oil separator 6 installed at a front surface of a heat exchanger of an evaporator 4. Refrigerant gas and oil are easily separated, the separated oil is returned back to a compressor 1 through an oil pipe 11 and then oil not separated is fed to the heat exchanger while the oil is being mixed with the refrigerant gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the operation of a heat pump, when the oil mixed with the refrigerant gas and circulated is easily separated from the refrigerant gas in the heat exchanger, before entering the heat exchanger. As much as possible, the separated oil is directly returned to the compressor, and the unseparated oil is sent to the heat exchanger together with the refrigerant gas.

[0002]

2. Description of the Related Art In a heat pump, generally, oil in a compressor is mixed with a refrigerant gas, discharged from the compressor, and returned to the compressor through a condenser, an expansion valve and an evaporator. Immediately after leaving the compressor, the refrigerant gas and the oil are completely separated and the refrigerant gas is sent as it is, and the oil is returned to the compressor, but it is rarely used or necessary at present because it is complicated and expensive. .. However, among the CFCs used as the refrigerant gas, especially R13 which is an alternative CFC gas.
In the case of 4a and the like, the refrigerant gas and the oil are easily separated in the condenser, especially in the evaporator having a low gas temperature. When the refrigerant gas and the oil are separated in the heat exchanger, the oil is stored and the heat exchange is not good. is there. Therefore, the conversion to alternative CFCs is not progressing at present. Therefore, research is being conducted to prevent the oil from being separated from the refrigerant gas by devising a compressor that does not evaporate the oil, or by heating the gas to be cooled immediately after it leaves the expansion valve.

[0003]

Therefore, the present invention is intended to solve the problem by promoting the separation of oil on the heat exchanger side without changing the compressor section.
A simple oil separator is attached to the front of the condenser and the evaporator, and when the oil becomes easy to separate due to changes in operating conditions, especially when the temperature of the refrigerant gas drops, the separated oil is stored in the oil separator and the compressor The oil that has not been separated yet is sent directly to the heat exchanger together with the refrigerant gas.

[0004]

Referring to the drawings, FIG. 1, a compressor 1, a condenser 2, an expansion valve 3,
In a heat pump consisting of an evaporator 4 and a gas pipe 5 connected between them, an oil separator 6 is installed on one or both of the front surface of the condenser 2 and the front surface of the evaporator 4.

This oil separator 6 is shown in FIG. 2. An oil tank 8 is attached to the lower part of a case 7, a sensor 10 for determining the oil position is installed, a position 9 for storing the oil is determined, and an oil pipe is provided under the position. 11 is attached, the inlet of the oil pipe 11 is always invaded with oil to prevent refrigerant gas from entering, and the oil pipe is directly connected to the compressor 1. When the fins 12 are attached to the inside of the case 7 and the gas pipes 5 and 5'are installed at different positions, and are attached to the front surface of the condenser 2, the gas pipe 5 and the compressor 1 are connected and the gas pipe 5'is connected to the condenser 2. Similarly, when it is attached to the front surface of the evaporator 4, the gas pipe 5 is connected to the expansion valve 3 and the gas pipe 5 ′ and the evaporator 4 are connected.

It is effective to let the gas flow at a distance of 100 mm or more between the gas pipes 5 and 5 ', and when the case 7 has twice the length of the gas pipe 5 or more, even if the fin 12 is attached inside,
The oil never clogs. Further, a plurality of pipes 5 and the same diameter may be used without fins to form a slave type. The case 7 and the oil tank 8 may be integrated, or as shown in FIG. 3, the case 7 may be turned sideways to form an oil tank at the bottom, and the oil pipe 11 may be attached to the lower part thereof.
Further, as shown in FIG. 4, the same effect can be obtained even if the front part of the condenser and the evaporator are oil separators and the oil pipe is attached to the lower part so as to be integrated with the heat exchanger.

[0007]

When the heat pump is operated with this, the refrigerant gas and the oil are mixed and discharged from the compressor 1, enter the oil separator 6 attached to the front surface of the condenser 2, and hit the fins 12 to separate the oil. The oil which is not separated here and which is not separated here enters the condenser 2 together with the refrigerant gas, but is rarely separated in the condenser 2. When the oil exceeds the oil position 9, the oil sensor 10 is activated, the inlet of the oil pipe 11 is opened, and the oil is returned to the compressor through the pipe 11. Since the oil pipe 11 is located below the oil position 9, the refrigerant gas from the oil pipe 11 does not return to the compressor 1 without passing through the heat exchanger. When the oil separator 6 is attached to the front surface of the evaporator 4, the movement is similar to that when it is attached to the front surface of the condenser, but the heat exchange is less than that of the evaporator, and the inside of the case 7 is more than 3 inside the evaporator 4. Make it easy to separate the oil by lowering the temperature above ℃.
When the oil stored in the oil tank 8 is connected to the gas suction pipe 5 of the compressor 1, it is sucked into the compressor 1 together with the refrigerant gas passing through the evaporator 4, and the oil in the compressor does not run out.

[0008]

EXAMPLE An oil separator 6 was manufactured as shown in FIG. 2 with a case having a length of 50 mm and a length of 200 mm, and both were attached to the front faces of a condenser 2 and an evaporator 4. The heat pump used was 3 Hp, condenser 2 and evaporator 4 together air cooled. As the refrigerant gas, an alternative CFC 134a, which is said to have poor oil familiarity, was used. In normal operation, oil was hardly separated, but when the amount of oil was too large, or when the refrigerant gas temperature was low during winter operation, the expansion valve was too throttled and the refrigerant gas blowout temperature was extremely low. It was confirmed by the liquid level gauge 13 attached to the oil tank that the oil was separated when it became and the oil was stored in the oil tank 8. The oil that has not been separated by the oil separator 6 does not separate even if it passes through the heat exchanger while being mixed with the refrigerant gas, and the heat pump operates normally.

[0009]

[Effects of the Invention] Even if an alternative CFC gas which is said to have poor oil familiarity is used, the refrigerant gas and the oil are separated in the heat exchanger by attaching the oil separator 6 and separating the oil and returning it to the compressor 1. As a result, the oil can be retained and the refrigerant gas can hardly pass through, and the compressor 1 can run normally with the current heat pump without running out of oil.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of the present invention.

FIG. 2 is a schematic diagram showing a configuration of an oil separator in the present invention.

FIG. 3 is a schematic view showing a configuration in which the oil separator is laid sideways.

FIG. 4 is a schematic diagram showing a configuration in which an oil separator and a heat exchanger are integrated.

[Explanation of symbols]

 1 ... Compressor 2 ... Condenser 3 ... Expansion valve 4 ... Evaporator 5 ... Gas pipe 6 ... Oil separator 7 ... Oil separator case 8 ... Oil tank 9 ... Oil position 10 ... Oil position Sensor 11 ... Oil pipe 12 ... Fin 13 ...

Claims (1)

[Claims] 1. In a heat pump comprising a compressor (1), a condenser (2), an expansion valve (3) and an evaporator (4), a refrigerant gas and an oil are separated in front of a heat exchanger such as a condenser and an evaporator. The oil separator (6) is attached, the oil pipe (11) is connected to the compressor from the oil separator (6), and the separated oil is returned to the compressor (1) and is not separated by the oil separator (6). Is a heat pump fitted with an oil separator that is sent to a heat exchanger together with refrigerant gas.