JPS62108966A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to refrigeration equipment used outside super showcases and large refrigerators. Regarding equipment.

(B) Conventional technology Conventionally, this type of refrigeration equipment has been described in Japanese Patent Publication No. 60-23261 and as shown in FIG. two evaporators,
24.25 and an expansion valve 26.27 individually connected to the inlet flllll of each evaporator.
While two evaporators 24 and 25 are installed in the same refrigerator, the temperature inside the refrigerator or the low pressure of the compressor 21 is detected by the temperature sensor 28 or the pressure sensor 29, and this detected value is set in advance. When the load is higher than the preset upper limit, that is, the load is large, the compressor 21 continues to operate, and when it is lower than the preset lower limit, that is, the load is small, the compressor is stopped to maintain the temperature inside the refrigerator. It was designed so that it could be maintained.

(C) Problems to be Solved by the Invention However, according to the above configuration, the compressor starts or stops when the temperature inside the refrigerator or the low pressure of the compressor exceeds a preset upper limit or lower limit. There is a problem in that the temperature inside the refrigerator fluctuates over a wide range due to sudden rises and falls in the internal temperature.

In addition, in order to suppress fluctuations in the temperature inside the refrigerator, the differential between the upper and lower limits can be set small, but in this case, the compressor will start and stop frequently, and the control parts of the compressor will be damaged. There are problems in that the device is easily damaged and power consumption increases. For this reason, in a refrigeration system with such a configuration, the temperature inside the refrigerator should be adjusted by ±0.5 to 1, for example.
It has been difficult to control the temperature with high accuracy within the range of ℃.

The present invention was developed in view of these points, and it prevents the compressor from stopping when the refrigeration equipment is under a light load, suppresses changes in the evaporator air temperature and ambient temperature, and maintains the temperature inside the refrigerator with little fluctuation. The purpose is to control with high precision.

(d) Means for Solving the Problems The present invention provides a refrigeration system equipped with a compressor, a condenser, a plurality of evaporators connected in parallel, and a pressure reducing device individually connected to the inlet side of each evaporator. In the apparatus, a solenoid valve is provided on the outlet side of one evaporator among the plurality of evaporators, and a bypass pipe that can be read directly between the one evaporator and the solenoid valve from the discharge side of the compressor is provided. The bypass pipe is provided with an electric valve that adjusts the flow rate by being activated by a signal from a sensor that detects the temperature of the mixed air from a plurality of evaporators or the ambient temperature.

(e) Function The refrigeration system of the present invention has the above-described configuration, so that when the load is large and the evaporator outlet temperature or ambient temperature is higher than a preset temperature, the solenoid valve is opened and the electric valve is closed. While the refrigeration system performs cooling operation, if the load becomes light and the evaporator outlet air temperature or ambient temperature drops below the preset temperature, the solenoid valve on the evaporator outlet side is closed. On the other hand, the electric valve is activated by the signal from the sensor that detects the outlet air temperature and the ambient temperature, and the opening degree of the electric valve is automatically adjusted according to the difference between the temperature detected by the sensor and the set temperature. It is possible to supply hot gas to the evaporator in an amount commensurate with the temperature drop of the entire evaporator, suppress the drop in the temperature and evaporation pressure of the entire evaporator, prevent a drop in the low pressure of the compressor, and reduce the pressure of the compressor. While the operation continues, the cooling capacity of the entire evaporator, which is the sum of the heating degree of the evaporator to which Horagas is supplied and the cooling degree of the evaporator in cooling operation, is balanced with the load in the eight warehouses. This makes it possible to accurately focus the temperature to a set temperature.

(f) Example Embodiments of the present invention will be described below based on the drawings.

1 includes a compressor 2, a condenser 3, a liquid receiver 4, two evaporators 5 and 6 installed close to each other and connected in parallel, and an expansion valve 7 connected individually to the inlet side of each evaporator. .8 is a solenoid valve provided on the outlet side of the evaporator 6. 1
0 is a bypass pipe connected from the discharge side of the compressor 2 between the evaporator 6 and the electromagnetic valve 9. This is an electric valve installed in the bypass pipe at No. 11. Reference numeral 12 denotes a temperature sensor that detects the temperature of the mixed air discharged from the two evaporators 5 and 6 and outputs a signal. Reference numeral 13 denotes an electric valve control device that adjusts the opening degree of the electric valve 11 based on the signal from this sensor. In this device, the target internal temperature is input in advance as a set temperature, and if the temperature detected by the sensor 12 is higher than the set temperature, it does not send a signal to the electric valve 11 and closes the electric valve. On the other hand, when the detected temperature becomes lower than the set temperature, a signal is sent to the motor-operated valve and the motor-operated valve is activated. Here, the motor-operated valve control device 13 outputs a wide signal commensurate with the difference between the detected temperature and the set temperature to the motor-operated valve 11, and the motor-operated valve 11 opens at an opening degree corresponding to the magnitude of the signal. Open. 14 is a bypass check valve connected in parallel to the expansion valve 8.

In the refrigeration system configured in this way, first, when the load inside the refrigerator is large and the outlet temperature of the evaporators 5 and 6 is higher than the set temperature inside the refrigerator preset in the electric valve control device 13, the electromagnetic valve 9 is opened, and since there is no signal from the motorized valve control device 13 to the motorized valve 11, the motorized valve is kept closed, and the gas discharged from the compression Ja2 is transferred to the condenser 3, liquid receiver 4, and expansion valve 7. , 8, and evaporators 5 and 6 to perform cooling operation as before.

Next, when the load inside the refrigerator becomes lighter and the temperature of the air blown into the evaporator 5 becomes lower than the set temperature inside the refrigerator preset in the electric valve control device 13, the solenoid valve 9 is closed and the electric valve control device 13 is closed. sends a signal of a magnitude corresponding to the difference between the detected temperature and the set temperature to the motor-operated valve 11 to operate the motor-operated valve, and as shown by the broken line in FIG. An amount of hot gas commensurate with the temperature decrease, that is, the decrease in the capacity of the evaporator 5.6 shown by the dashed line in FIG. 6 to the check valve 14 side. This allows the evaporator 5.6
A decrease in the overall blowout temperature and evaporation pressure is suppressed, a decrease in the low JE pressure of the compressor is prevented, and the compressor 2 can continue operating without stopping. Furthermore, a portion of the hot gas discharged from the compressor 2 is supplied to the evaporator 6, and the amount of the supplied hot gas is controlled by the electric valve 1.
1 can control the amount according to the overall blowout temperature of the evaporator 5 and 6, and the evaporator 5 is continuously operated for cooling, so the heating degree of the evaporator 6 and the temperature of the evaporator 5 are The cooling capacity of the entire evaporator 5.6, which is the sum of the cooling degrees, can be balanced with the load inside the refrigerator, keeping the cooling capacity of the refrigeration system constant and keeping the temperature inside the refrigerator close to the set temperature accurately. be able to.

In addition, in this embodiment, the case where two evaporators are installed close to each other to mix the blowing air from the entire evaporator is explained, but if the two evaporators are installed in a separate place or Even if the two evaporators are integrated, the same effect can be achieved as long as the air from the two evaporators can be mixed by using a duct or a fan, and even if these devices are used, the present invention can be achieved equally well. It's not something to deviate from.

Furthermore, the present invention can also be applied to systems that are equipped with a plurality of compressors and have variable refrigerating capacity, and the same effect can be obtained by incorporating a circuit like this embodiment into these systems. .

(G) Effects of the Invention As described above, the present invention provides a refrigeration system equipped with a compressor, a condenser, a plurality of evaporators connected in parallel, and a pressure reducing device individually connected to the inlet side of each evaporator. A solenoid valve is provided on the outlet side of one of the plurality of evaporators, and a bypass pipe is provided from the discharge side of the compressor between the one evaporator and the solenoid valve. This bypass pipe is equipped with an electric valve that adjusts the flow rate by being activated by a sensor signal that detects the temperature of the mixed air from multiple evaporators or the ambient temperature, so the load inside the refrigerator is reduced. When the air temperature of the evaporator or the ambient temperature drops below the preset internal temperature due to the lighter weight, an electrically operated valve supplies hot gas to one evaporator in an amount commensurate with the reduction in overall evaporator capacity. This reduces the temperature and evaporation pressure of the entire evaporator and prevents the low pressure of the compressor from decreasing.
The cooling capacity of the entire evaporator, which is the sum of the degree of heating of the evaporator that allows the compressor to operate continuously and the supply of hot gas, and the degree of cooling of the evaporator that is continuously operated for cooling, is calculated as the cooling capacity of the entire evaporator inside the refrigerator. This can be balanced with the load, thereby making it possible to maintain the refrigeration capacity of the refrigeration device at a substantially constant level and keep the internal temperature close to the set temperature with high accuracy.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the present invention, Figure 1 is a cold tofu circuit diagram of a refrigeration system, Figure 2 is a characteristic diagram showing the relationship between the refrigerating capacity and load of the refrigeration system, and Figure 3 is a conventional It is a refrigerant circuit diagram of a refrigeration device showing an example. 2... Compressor, 3... Condenser, 5.6...
・Evaporator 7.8...Expansion valve, 9...Solenoid valve,
1o...Bypass pipe, 11...Electric valve, 12.
··Temperature sensor. Applicant Sanyo Electric Co., Ltd. and 1 other representative Patent attorney Shizuo Sano Figure 2 Operated by the Royal Office Takehisa Figure 3

Claims (1)

[Claims] (1) In a refrigeration system equipped with a compressor, a condenser, a plurality of evaporators connected in parallel, and a pressure reducing device individually connected to the inlet side of each evaporator, among the plurality of evaporators,
A solenoid valve is provided on the outlet side of one evaporator, and a bypass pipe is provided that is connected from the discharge side of the compressor between the one evaporator and the solenoid valve, and a plurality of evaporators are connected to this bypass pipe. A refrigeration system characterized by being provided with an electric valve that adjusts the flow rate by being activated by a signal from a sensor that detects the temperature of the mixed blow-out air or the ambient temperature.