JPS6357626B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to temperature control of a compressor of a refrigeration system.

Conventional refrigeration systems generally have a refrigeration cycle in which refrigerant gas compressed by a compressor is circulated from a condenser through a throttle device, an evaporator, a suction pipe, and back to the compressor. In this refrigeration system, the temperature of the compressor changes due to a change in the ambient temperature where the compressor is installed, and the viscosity of the lubricating oil sealed in the compressor changes. The viscous resistance of each sliding part of the compressor changes due to changes in the viscosity of the lubricating oil, so even if the output of the compressor, that is, the refrigerating capacity, is the same, the mechanical input is
It has the characteristics shown in the figure. That is, when the compressor temperature is relatively high in the summer, the compressor input is small, and when the compressor temperature is relatively low in the winter, the compressor input is large.

In view of the above points, the present invention provides a refrigeration system that maintains the temperature of a compressor appropriately, and aims to save energy throughout the year.

An embodiment of the present invention will be described below with reference to FIG. 1 is a compressor, and inside the compressor 1, an electric compression element (not shown), a lubricating oil 2, and a lubricating oil heating pipe 3 are housed.
are arranged for heat exchange.

The flow of refrigerant passes through the compressor 1 and flows into the condenser 6 via a solenoid valve 5 controlled by a thermostat device 9 that directly or indirectly detects the temperature of the lubricating oil 2 in the compressor 1. The refrigerant circuit A branches from the compressor 1 and the solenoid valve 5 midway, passes through the resistance pipe 4 and the lubricating oil heating pipe 3, and connects to the solenoid valve 5.
and a second refrigerant circuit B that is connected to the condenser 6 and flows into the condenser 6 to form a parallel circuit.
The refrigerant that has passed through the condenser 6 is sent to a throttle device 7 and an evaporator 8.
The air flows through the compressor 1 again.

Next, the operation of the solenoid valve 5 will be explained. When the temperature of the lubricating oil 2 is relatively high, such as during summer, the electromagnetic valve 5 is kept open by the action of the thermostat device 9. At this time, the refrigerant flow is such that almost the entire amount of refrigerant gas discharged from the compressor 1 flows through the first refrigerant circuit A to the condenser 6 due to the action of the resistance pipe 4 of the second refrigerant circuit. Almost no high-temperature refrigerant gas flows through the lubricating oil heating pipe 3 of the second refrigerant circuit B and heats the lubricating oil 2.

On the other hand, when the temperature of lubricating oil 2 is low, such as during winter,
Due to the movement of the thermostat device 9, the solenoid valve 5 of the first refrigerant circuit A remains closed, and all the high-temperature refrigerant gas discharged from the compressor 1 passes through the lubricating oil heating pipe 3 of the second refrigerant circuit B. flows and heats the lubricating oil 2. When the heating continues and the temperature of the lubricating oil 2 reaches a predetermined temperature, the electromagnetic valve 5 is opened by the thermostat device 9, and the heating of the lubricating oil 2 is stopped. Such actions are repeated to maintain the temperature of the lubricating oil 2 at a predetermined temperature. Incidentally, since the lubricating oil 2 and the lubricating oil heating pipe 3 only have to be engaged for heat exchange, there is no problem in providing the lubricating oil heating pipe 3 on the outer periphery of the sealed container 9.

As described above, the refrigeration system of the present invention allows the refrigerant gas discharged from the compressor to flow into the condenser through the solenoid valve controlled by the thermostat device that directly or indirectly detects the temperature of the lubricating oil. a second refrigerant circuit that branches from the compressor and the solenoid valve midway, passes through a resistance pipe, and flows through a lubricating oil heating pipe that is locked in heat exchange with the lubricating oil to a condenser. Since this is a refrigeration system that can be selectively switched as needed, when the temperature of the lubricating oil is high in the summer, the gas discharged from the compressor is transferred to the first refrigerant circuit by the action of the resistance pipe in the second refrigerant circuit. Almost the entire amount flows directly to the condenser via the solenoid valve, so the temperature rise of the lubricating oil is extremely small, and the lubricity of the lubricating oil does not deteriorate due to a decrease in the viscosity of the lubricating oil. There is almost no thermal deterioration. Also, since the lubricating oil heating pipe at this time is arranged to exchange heat with the lubricating oil, the refrigerant in the lubricating oil heating pipe is in a superheated gas state and there is no accumulation of liquid refrigerant, and the volume of the resistance tube is extremely small. Due to heat conduction from the first refrigerant circuit and the lubricating oil heating pipe, there is no accumulation of liquid refrigerant in a superheated gas state, and there is no reduction in the refrigeration effect. On the other hand, when the temperature of the lubricating oil is low, such as during winter, all the gas discharged from the compressor flows through the lubricating oil heating pipe of the second refrigerant circuit, and the thermostat keeps the lubricating oil at a predetermined temperature. It is possible to maintain the viscosity at a low and appropriate viscosity,
It has the characteristics of reducing mechanical input to the compressor and reducing energy consumption. By setting the thermostat temperature to below the lubricating oil temperature during summer operation, the practical effect is that the compressor's thermal and mechanical durability can be maintained at the same level or higher than conventional products. It is a large refrigeration device.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between compressor temperature and compressor input of a conventional refrigeration system, and FIG. 2 is a refrigerant circuit diagram of a refrigeration system showing an embodiment of the present invention. 1... Compressor, 2... Lubricating oil, 3... Lubricating oil heating pipe, 4... Resistance pipe, 5... Solenoid valve, 6...
Condenser, A...first refrigerant circuit, B...second refrigerant circuit, 8...evaporator, 9...thermostat device.

Claims (1)

[Claims] 1. A refrigeration system configured by sequentially connecting a compressor, a condenser, a throttle device, and an evaporator, the first refrigerant circuit having a solenoid valve between the compressor and the condenser, and the first refrigerant circuit. A second refrigerant circuit in which a resistance pipe and a lubricating oil heating pipe are connected in series is provided in parallel with the lubricating oil, and a thermostat device that directly or indirectly detects the lubricating oil temperature controls the opening of the solenoid valve when the temperature is cold. Characteristic refrigeration equipment.