JPH0650616A - Freezing unit - Google Patents

Abstract

PURPOSE:To prevent the frosting over an evaporator as the consumption power of a freezing unit is prevented from exceeding a set value by providing a means to detect the consumption power of the freezing unit and a controller to switch an evaporator fan to low speed operation when the detected power attains a set value. CONSTITUTION:The consumption power of a freezing unit is detected by means of a power detecting means 50. A detected value P is inputted to a comparing means 52 of a controller 51, and the detected value is compared with a set value PS, inputted from 8 set means 53, thereby. When the detected value P attains the set value PS, the comparing means 52 outputs it to a switching means 54, and the switching means 54 switches an evaporator fan 12 to low speed operation by switching the tap of a fan motor 11 to the lower speed side. This constitution prevents the occurrence of frosting to an evaporator as the consumption power of the freezing unit is prevented from exceeding a set value. Further, freezing capacity can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating unit such as a container.

[0002]

2. Description of the Related Art A conventional container is shown in FIG.
The container 1 has a rectangular parallelepiped shape, and a refrigeration unit 100 is attached to one end wall 2 of the container 1. By storing a cargo in the container 1 through a door (not shown) provided on the other end wall of the container 1 and operating the refrigeration unit 100, the air temperature inside the container 1 is kept within the range of -30 ° C to + 30 ° C. The container 1 is carried on a vessel, a truck, a railroad vehicle, etc., while being maintained at a temperature arbitrarily set by.

A schematic structure of the refrigerating unit 100 is shown in FIG. 4, (A) is a front view, (B) is a sectional view taken along the line BB of (A), and (C) is a rear view. . The gas refrigerant discharged from the compressor 3 enters the water cooling condenser 5 or the air cooling condenser 4 and is condensed and liquefied there. The liquid refrigerant enters the electronic expansion valve 9 through the dryer 7 and the strainer 8 and is throttled there to undergo adiabatic expansion to become a gas-liquid two-phase refrigerant. This refrigerant enters the evaporator 10, where it evaporates and vaporizes by cooling the air in the refrigerator blown from an evaporator fan 12 driven by a second speed motor 11 capable of switching between low speed and high speed. And this gas refrigerant is an accumulator.
Return to compressor 3 via 13.

As shown by the solid arrow, the air in the container 1 enters the evaporator section 15 from the suction port 14 and is urged by the evaporator fan 12, and is cooled in the process of passing through the evaporator 10. Wind path 16, blowout room
It returns to the inside of the container 1 via 18 and is blown out from the gap of many T rails 43.

When the air-cooled condenser 4 is used, the motor
The condenser fan 6 is driven by 17. Then, after the temperature of the outside air is increased by exchanging heat with the gas refrigerant in the process of passing through the air-cooled condenser 4, as indicated by the dashed arrow,
The capacitor fan 6 is energized and discharged.

When using the water-cooled condenser 5, a water supply valve and a drain pipe (not shown) are connected to the cooling water inlet 19 and the cooling water outlet 20 to open the water control valve 21. Then, the cooling water supplied from the water supply pipe enters the water cooling condenser 5 through the water pipe (not shown) from the cooling water inlet 19 and heats up there by exchanging heat with the gas refrigerant. The water is discharged from the cooling water outlet 20 through the water valve 21 and the drain pipe.

The drain condensed on the evaporator 10 is dropped on the drain pan 22 and is passed through the drain hose 23 to the drain port.
Emitted from 24.

Reference numeral 41 denotes an inner and outer partition wall made of a heat insulating material, which is fastened to the end wall 2 of the container 1 by a flange formed on the entire circumference thereof. A condenser section 42 is formed at the center of the lower part on the outside of the heat insulating wall 41, an evaporator section 15 is provided on the upper side of the condenser section 42, an air passage 16 is blown on both sides of the inner and outer partition wall 41, and blown to the lower side. Each chamber 18 is formed. An evaporator 10, an evaporator fan 12, etc. are installed in the evaporator section 15. In the condenser section 42, the compressor 3,
An air-cooled condenser 4, condenser fan 6 and the like are installed.

Reference numeral 25 is a control box, 26 is a solenoid valve for liquid injection for injecting and cooling a liquid refrigerant into the compressor 3, 27 is a 200V class power plug,
28 is a 400V class power supply plug, 29 is a power transformer, 31 is an intake air temperature sensor for detecting the temperature of the air in the refrigerator that is sucked into the evaporator 10, 30 is an insertion port of a thermometer for checking the temperature sensor 31, 33 is a blown air temperature sensor for detecting the temperature of the air blown from the evaporator 10, 32 is an insertion port of a thermometer for checking the temperature sensor 33, and 34 is an outlet for detecting the refrigerant outlet temperature of the evaporator 10. A temperature sensor, 35 is an overheat prevention sensor, 36 is a discharge pipe temperature sensor for detecting the temperature of the discharge pipe of the compressor 3, 37 is an outside air temperature sensor for detecting the temperature of the outside air flowing into the air cooling condenser 4, and 38 is An inspection lid for inspecting the equipment in the evaporator section 15, 39 is a handle for attaching and detaching the inspection lid 38, and 40 is a ventilation device.

When refrigerated cargo is stored in the container 1,
That is, in the chill mode, the set temperature of the inside air temperature is set to a predetermined value (for example, -5 ° C) or more, and the evaporator fan 12 is operated at high speed in order to keep the temperature distribution in the container 1 uniform. Then, when the frozen cargo is stored in the container 1, that is, in the frozen mode, the set temperature of the inside air is set to a predetermined value (for example, -5 ° C) or less, and there is no problem even if the temperature distribution in the container 1 is bad. Therefore, the evaporator 12 is operated at a low speed.

[0011]

In the conventional refrigeration unit, when the power consumption thereof increases and reaches a predetermined value,
Although the power consumption was prevented from exceeding a predetermined value by squeezing the electronic expansion valve 9, squeezing the electronic expansion valve 9 lowers the evaporation temperature, so that frost is likely to adhere to the evaporator 10 and There is a problem that the air temperature inside the refrigerator cannot be maintained at a desired value because the refrigerating capacity is lowered.

[0012]

SUMMARY OF THE INVENTION The present invention has been invented to solve the above-mentioned problems, and the gist of the present invention is to provide a refrigeration unit equipped with an evaporator fan whose speed is variable. The refrigeration unit is provided with a means for detecting power and a controller for switching the evaporator fan to low speed operation when the detected power reaches a set value.

[0013]

In the present invention, because of the above configuration, the evaporator fan is switched to the low speed operation when the power consumption of the refrigeration unit reaches the set value.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be specifically described with reference to FIGS. A control block diagram is shown in FIG. The power consumption of the refrigeration unit is detected by the power detection means 50. The detected value P is input to the comparison means 52 of the controller 51, and is compared with the set value P _s input from the setting means 53 here. When the detected value P reaches the set value P _s , the comparison means 52 outputs it to the switching means 54 and the switching means 54.
Switches the evaporator fan 12 to low speed operation by switching the tap of the fan motor 11 to the low speed side. Other configurations are similar to those of the conventional one shown in FIGS. 3 and 4.

However, if the air volume of the evaporator fan 12 is reduced to half, the power required to drive the evaporator fan 12 is reduced to 1/8 and the fan motor is reduced.
Since the heat radiation from 11 to the inside air is reduced, the refrigeration unit
Power consumption of 100 is reduced.

Therefore, the relationship between the power consumption and refrigerating capacity of the refrigeration unit 100, the air temperature in the refrigerator, and the speed of the evaporator fan 10 is as shown in FIG. 2, and the evaporator fan 10 is switched from high speed operation to low speed operation. This can reduce the power consumption of the refrigeration unit and at the same time improve the refrigeration capacity of the refrigeration unit.

If the amount of air blown into the container 1 is reduced by switching the evaporator fan 12 to a low speed operation, the temperature distribution in the container 1 may be deteriorated. Therefore, a plurality of evaporator fans 12 should be provided. If so, it is desirable to sequentially switch the plurality of evaporator fans 12 to the low speed operation according to the increase in power consumption of the refrigeration unit.

[0018]

According to the present invention, when the power consumption of the refrigerating unit reaches the set value, the evaporator fan is switched to the low speed operation, so that the power consumption of the refrigerating unit is prevented from exceeding the set value. Frost can be prevented and the refrigerating capacity can be improved.

[Brief description of drawings]

FIG. 1 is a control flowchart showing an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship among power consumption and refrigerating capacity of a refrigerating unit, air temperature in a refrigerator, and speed of an evaporator fan.

FIG. 3 is a schematic perspective view of a conventional container.

FIG. 4 shows a schematic configuration of a conventional container refrigeration unit, (A) is a front view, (B) is a cross-sectional view taken along the arrow BB of (A), and (C) is a rear view. is there.

[Explanation of symbols]

 50 Power detection means 53 Setting means 51 Controller 52 Comparison means 54 Switching means 12 Evaporator fan

Claims (1)

[Claims] 1. A refrigeration unit including a variable speed evaporator fan, a means for detecting power consumption of the refrigeration unit, and when the detected power reaches a set value,
A refrigeration unit provided with a controller for switching the evaporator fan to a low speed operation.