JPS589347B2 - Reitou Souchino Anzen Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention detects and notifies an insufficient or excessive amount of refrigerant gas in a refrigeration cycle of an automobile cooling system, etc.
This invention relates to a safety device for refrigeration equipment that stops the refrigeration equipment.

In a refrigeration system, refrigerant may leak from piping connections or equipment connections, resulting in a shortage or no refrigerant.

Particularly in a vehicle cooling system, since the compressor during the cycle is of an open type, it is difficult to completely eliminate refrigerant leakage.

If the system is operated with too little refrigerant, not only will the cooling effect not be sufficient, but the lubricating oil that has leaked into the refrigerant may return to the compressor, causing seizure of the compressor's sliding parts. .

In addition, if a refrigeration system is left for a long time without refrigerant, that is, with air infiltrating instead of refrigerant, the intruding air will oxidize the pipes and equipment in the cycle, causing the pipes and constrictions to become clogged. may stop working.

On the other hand, if the compressor is operated in a state where it is overfilled with refrigerant, the discharge pressure of the compressor becomes abnormally high, causing damage to the valve of the compressor.

The purpose of the present invention is to solve the above-mentioned problems and provide a safety device that can stop the operation of the compressor or issue an alarm when the amount of refrigerant charged is too low or too high. The purpose of this invention is to provide a safety device that is simple to configure and inexpensive.

The feature of the present invention is that the refrigerant pressure discharged from the compressor changes proportionally to the outside temperature between the lower limit and the upper limit of the refrigerant filling amount that does not cause any trouble to the cycle, as shown in Figure 1. Focusing on this, we provided a detection unit consisting of a pressure sensor that generates an electric signal in response to changes in the refrigerant pressure discharged from the compressor and an outside temperature sensor that generates an electric signal in response to changes in outside temperature. When the electric signals generated by both sensors reach a predetermined relationship, that is, when the electric signal generated by the pressure sensor is no longer proportional to the electric signal generated by the outside temperature sensor, the alarm device or refrigeration equipment stop device is activated. The point is that a protective device activation circuit is provided to prevent

According to the embodiment, a pressure sensor whose resistance value changes in a fixed relationship according to changes in applied pressure and a temperature sensing element such as a thermistor whose resistance value changes in a fixed relationship according to changes in outside air temperature are placed on adjacent sides. A bridge circuit is provided, and when the values of both elements change in a relationship that disturbs the balance of the bridge circuit, the output of the bridge circuit activates an alarm or a stop device for the refrigeration system.

The present invention will be explained below with reference to embodiments shown in the drawings.

In FIG. 2, in a refrigeration system consisting of a compressor 1, a condenser 2, a liquid receiver 3, an expansion valve 4, and an evaporator 5, the discharge refrigerant pressure of the compressor 1 is measured by a pressure sensor 7 near the condenser 2. Let it be detected.

This pressure sensor 7 and a separately provided outside air temperature sensor 8 for detecting outside air temperature form a bridge circuit, and the output thereof is applied to a relay 10 via an amplifier 9.

This relay serves as a switch that connects and disconnects the electromagnetic clutch 6 that transmits the driving power of the compressor 1.3 In such a device, when the amount of refrigerant in the refrigeration system becomes too much or too little, the discharge refrigerant pressure changes and the pressure increases. Sensor 7 and outside temperature sensor 8
When the balance of the bridge circuit consisting of Lamp 1 instead of relay 10 in Fig. 2
2 is installed, and when an abnormal condition such as an excess or deficiency of refrigerant occurs, a lamp 12 is lit to issue an alarm.

FIG. 4 shows yet another embodiment, and some recent automotive cooling systems are equipped with an amplifier to automatically control the temperature inside the vehicle. The amplifier is shared.

That is, it has an indoor temperature sensor 14, an amplifier 9, and a relay 13, a compressor 1, a condenser 2, a liquid receiver 3, an expansion valve 4, and an evaporator 5.
In the refrigeration system, the existing one automatically controls the temperature inside the vehicle by turning on and off the relay 13 according to the output of the internal temperature sensor 14 to connect and disconnect the electromagnetic clutch 6 that transmits the drive power of the compressor 1. In addition, a pressure sensor 7, an outside temperature sensor 8, a lamp 12, and a relay 10 are provided, and a safety device that uses an amplifier 9 in common is attached, and sharing the amplifier is desirable from an economic point of view.

According to the present invention, as is clear from the above explanation, not only the shortage of refrigerant amount but also overfilling can be detected accurately depending on the outside temperature and with the same detection unit, so that it is possible to detect excess or deficiency of refrigerant amount. This has the great effect of reliably preventing accidents caused by.

Furthermore, the compressor does not malfunction when starting up, and the structure is simple and inexpensive.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the relationship between the refrigerant filling amount of the refrigeration system and the refrigerant pressure on the discharge side of the compressor, and Figs. 2 to 4 are electric circuit diagrams showing embodiments of the present invention, or electric circuits and refrigeration cycles. It is a diagram combining systems. 1...Compressor, 6-electromagnetic clutch, 7...Pressure sensor, 8...
Outside temperature sensor, 9...amplifier, 10...relay, 12...lamp. ■Claim 1 An entrance for inserting one food storage tray in the upper part,
In addition, a prismatic cylindrical tray housing section is provided adjacent to the inner circumferential wall of the prismatic cylindrical cooling tower, which has an outlet at the bottom for discharging the trays onto an endless conveyor belt, and a prismatic tray accommodating section is provided on the opposite side wall of the cylindrical cooling tower in the direction of flow of the coolant. The coolant is caused to flow oppositely through the gap of the descending stack of trays by fixing fixed wave deflectors with waveforms out of phase with respect to each other to deflect the bottom tray of the tray stack. A refrigeration device that is supported by bullets provided at the bottom and that sequentially lowers the stack by engaging drive pinions in holes in both end walls of the tray. DETAILED DESCRIPTION OF THE INVENTION Conventionally, when manufacturing frozen foods, a conveyor was run through a relatively long tunnel in order to rapidly freeze raw or processed foods, but this method required a large amount of space for the equipment. Furthermore, not only does it require a large amount of a coolant such as liquid nitrogen, but also the cooling efficiency is low because a large surface area of the material is exposed to the coolant and the coolant does not come into complete contact with the material. The present invention relates to a refrigeration system devised to eliminate these drawbacks. According to the present invention, a stack of food storage trays is inserted into a rectangular cylindrical cooling tower, and while they are lowered one after another, coolant is supplied alternately in opposite directions through the upper and lower parts of the trays. Not only can the freezing space be greatly reduced, but the time required for freezing can also be shortened because the top and bottom surfaces of the food are affected by the coolant flowing in opposite directions while the tray is lowering. , the freezing effect is extremely high, and the consumption of coolant is also small. Referring now to the drawings, 10 is a cooling tower, 94 is a horizontal conveyor, and 14 is a tray containing raw or cooked food, which is charged into the tower through an inlet 16. Food may or may not be packaged. The trays descend inside the column, and finally the lowest tray is taken out of the machine from the outlet 18 by the conveyor 94. The tray 14 consists of a bottom surface, side walls 20 and front and rear walls 22,
The side surface is provided with a hand hole 24 and left and right holes 26. The front and rear walls 22 are lowered so that when the trays are stacked, they form a front-to-back passageway 28 between the trays through which coolant flows and contacts the food product. Tower 10 is an upright cylinder formed from side walls 32 and front and rear walls 34,36. The peripheral walls 32, 34, 36 are formed of a suitable insulating material (eg, commercially available cellular plastic) and each wrapped in a thin metal sheet 38, such as stainless steel. The tray accommodating portion 72 within the tower is provided at a distance from the inner surface of the walls 32, 34, 36 to prevent the tray accommodating portion from bowing due to large differences between the internal low temperature and the ambient temperature. The inner surfaces of the side walls 32, 34, and 36 contract due to the internal freezing temperature, and the outer surfaces do not contract as much and tend to curve outward, but the tray receiving portion 72 is isolated from the peripheral wall and does not curve as described above. Therefore, there is no risk of interfering with the lowering of the tray.

Claims (1)

[Claims] 1 A device that detects an abnormal amount of refrigerant in a refrigeration cycle and activates a protection device such as an alarm device or a compressor stop device, which generates an electrical signal in response to changes in the refrigerant pressure discharged from the compressor. a pressure sensor; an outside temperature sensor that generates an electrical signal in response to a change in outside temperature; and an output that generates an output when the electrical signal generated by the pressure sensor is no longer proportional to the electrical signal generated by the outside temperature sensor; A safety device for a refrigeration system, comprising: a protection device activation circuit that operates the protection device using the output thereof.