JPS6140899B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration system such as an electric refrigerator, and more particularly to a control device for a refrigeration system that reduces energy loss during operation and stop of a refrigeration cycle.

Generally, in a refrigerator or the like, in order to maintain the internal temperature at a predetermined temperature, cooling operation and stopping are repeated over a certain temperature range. When the temperature inside the refrigerator drops to a predetermined temperature, this temperature is sensed and a signal to stop the cooling operation is issued, the electric compressor stops, and the refrigerant state in each part of the refrigeration cycle changes toward balance. In other words, the high-pressure side from the discharge valve of the electric compressor to the inside of the shell and condenser and the low-pressure side from the cooler to the suction port in the electric compressor maintain a balance pressure. Since the high-pressure gas refrigerant moves from the high-pressure gas refrigerant to the low-pressure side low-temperature part (in this case, the cooler), the inside of the cooler is filled with refrigerant. The temperature of the cooler rises due to the surrounding heat, but when the refrigerant flowing into the cooler from the capillary or electric compressor condenses and changes, the temperature rises rapidly and warms the surrounding air. It often happens.

Therefore, when the temperature inside the refrigerator rises to a predetermined temperature and the electric compressor receives a cooling operation signal and is operated, the liquid refrigerant that has accumulated in the cooler is not completely evaporated in the cooler and reaches the electric compressor. Since the inside of the piping is cooled and then flows to the electric compressor, the inside of the refrigerator is not effectively cooled for several minutes after startup, resulting in energy loss. When it is sucked into the machine, the compression work increases and the electric motor becomes overloaded, so the input is usually extremely large, and a larger electric motor is inevitably used to deal with this.

The present invention was made for the purpose of eliminating such problems in conventional refrigerant systems.The present invention will be described in detail below with reference to the illustrated embodiments. 2 is a condenser, 3 is a capillary tube, 4 is a cooler,
These are sequentially connected to form a refrigeration cycle. Reference numeral 5 denotes a check valve connected to the piping between the electric compressor 1 and the cooler 4. Reference numeral 6 denotes an on-off valve operated by a pressure signal, which is connected in the piping path between the condenser 2 and the capillary tube 3. 7 is a pressure signal pipe for operating the on-off valve 6; when the pressure between the electric compressor 1 and the check valve 5 is high, the on-off valve 6 is closed;
It is arranged to be in an open state when the pressure is low. Next, to explain the operation of the refrigeration cycle constructed from these, a refrigerant circulates within the refrigeration cycle, and in a refrigerator that is in cooling operation, when the temperature inside the refrigerator drops to a predetermined temperature, the temperature sensor etc. stops the refrigerator. A signal is issued and the electric compressor stops.

When the electric compressor 1 stops, the high-temperature, high-pressure gas refrigerant confined within the high-pressure shell flows back toward the cooler 4 through the oil film seal on the sliding surface of the rolling piston 1a and the like. At this time, a check valve 5 connected to the piping between the cooler 4 and the electric compressor 1 to prevent backflow from the electric compressor 1 to the cooler 4 instantly blocks the piping, At the same time, the on-off valve 6, which was open during operation due to the low pressure between the electric compressor 1 and the check valve 5, prevents the temperature from rising due to the high-temperature, high-pressure gas refrigerant in the cooler 4. When the check valve 5 is blocked, the piping line between the check valve 5 and the electric compressor 1 becomes high pressure due to the reverse flow of high pressure gas, and the on-off valve 6 is closed due to the pressure signal pipe connected to the part, from the condenser 2 to the cooler 4. Cut off the refrigerant flow. As shown in Figure 2, the pressure change after a refrigerant cycle stop signal is issued by a temperature sensor, etc., causes a high pressure curve a in the conventional refrigeration cycle.
The balance state of the low pressure curve b is on the high pressure side from the condenser 2 through the capillary tube 3, and the gas refrigerant sealed in the high pressure shell is separated from the sliding surfaces of the rolling piston 1a etc. to form a so-called low pressure side cooler. Since the refrigerant was gradually flowing out into the chamber, it took the time indicated by the balance point.
In the embodiment according to the present invention, the internal pressure a' from the inside of the high-pressure shell of the electric compressor 1 through the condenser 2 to the on-off valve 6 exhibits a pressure state higher than the conventional high-pressure side pressure, and gradually Stable at the same saturation pressure as temperature.

On the other hand, the low-pressure side pressure b' from the cooler 4 to the check valve 5 disposed in the piping of the electric compressor 1 indicates that there is no refrigerant intruding from the high-pressure side, and the refrigerant is confined on the low-pressure side immediately after the stop. flows into the part of the cooler 4 where the temperature has dropped the most, and is affected by heat from the surroundings of the piping and the cooler 4, causing a short delay until a signal to start the next cooling operation is issued and the electric compressor 1 is started. The pressure state on the low pressure side can be maintained in a state extremely close to the pressure state during normal operation, similar to the pressure state on the high pressure side during stoppage, by increasing the pressure by a small amount. Furthermore, when the electric compressor 1 is stopped, the high pressure gas in the shell is checked by the sliding surface of the rolling piston 1a, etc. of the electric compressor 1, which has a high pressure shell of the rolling piston 1a type, which is an embodiment of the present invention. A reverse flow passes through the oil film seal on the sliding surface in the direction of the valve 5 due to the force of the differential pressure, and at the same time the check valve 5 is activated, a high pressure curve is created between the electric compressor 1 and the check valve 5.
It changes as shown by a'', and the front and rear of the electric compressor 1 can be balanced at high pressure.

Next, when a signal to start cooling operation is issued by a temperature sensor, etc., the electric compressor 1 also starts operating at the same time, and the gas in the piping between the check valve 5 and the electric compressor 1 is sucked and the pressure is reduced. The on-off valve 6 is opened by the pressure signal pipe 7 of the section, and the refrigerant circulation from the condenser 2 to the cooler 4 is started. Conventionally, the liquid refrigerant that had accumulated in the cooler 4 during stoppage returned to the electric compressor 1 without cooling the cooler (4), causing a pressure increase, but in the present invention. In the , the normal temperature and normal pressure refrigerant accumulated in a liquefied state in the condenser 2 flows through the capillary tube 3 as the electric compressor 1 operates, and the pressure is reduced.After the cooler 4 evaporates and performs the cooling effect, the refrigerant is converted into gas. The refrigerant returns to the electric compressor 1 as a refrigerant, making it possible to reduce the input by reducing the load at the time of starting the electric compressor 1, and making it possible to make the electric motor more compact than in the past.

Since the present invention is configured as described above, it is possible to eliminate energy loss mainly caused by the movement of refrigerant in a conventional refrigeration cycle, especially immediately after the operation and stop of the refrigeration cycle, and also, This makes it possible to downsize the motor of the electric compressor and improve energy efficiency even during normal operation.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration circuit diagram according to an embodiment of the present invention,
FIG. 2 is an explanatory diagram showing the pressure balance state after the refrigeration cycle is stopped in the refrigeration cycle of the present invention and the conventional refrigeration cycle. 1 is an electric compressor, 2 is a condenser, 3 is a capillary tube, 4
5 is a cooler, 5 is a check valve, 6 is an on-off valve, and 7 is a pressure signal pipe.

Claims (1)

[Claims] 1. In a refrigeration cycle consisting of an electric compressor, a condenser, a capillary tube, and a cooler connected in sequence with high pressure inside the shell, a check valve is provided in a part of the piping connecting the electric compressor and the cooler. A refrigeration system characterized in that an on-off valve is disposed near a connection between a condenser and a capillary tube and is operated by a pressure change between an electric compressor and a check valve when the refrigeration system is started or stopped.