JPH0268214A - Refrigerator for vehicle - Google Patents

Abstract

PURPOSE:To increase the refrigerating capacity without making the size of the device too large by providing thermally a cold accumulating pack and fins on the evaporation tube of an evaporator to cool the air inside a refrigerator of a vehicle. CONSTITUTION:A sprayed coolant depressurized and expanded by an expansion valve 4 is evaporated by an evaporator 5 of a cooling unit 10 which is arranged in a refrigerator, and the inside of the refrigerator is cooled because the heat is absorbed from the surrounding in the evaporation. As a result, a cold accumulating pack 6 arranged contacting thermally to a tube 5a for evaporation of the evaporator 5 is cooled to the freezing point and frozen. On the other hand, the air inside the refrigerator is cooled directly by fins 7 arranged contacting to the evaporation tube 5a. The effect of the cooling operation of the fins 7 not only increases the cooling-down performance during the operation of the refrigerator, but also contributes to the cooling performances in the cooling condition only by the cold accumulating pack 6 when the freezer is stopped, by the effect of synergism.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicular refrigerator, and more particularly to a regenerator type vehicular refrigerator that can keep the inside of the refrigerator cool even when the vehicle is parked.

[Conventional technology]

As a cold storage type vehicle refrigerator, for example,
As disclosed in Publication No. 413, a cold storage plate is additionally arranged in series with the evaporator installed in the refrigerator of the refrigerator, and when the vehicle is running, the inside of the refrigerator is evaporated by the operation of the refrigerator. There is a known system that cools the inside of the refrigerator and cools the refrigerator using the latent heat of fusion of the cold storage plate when the vehicle is parked when the refrigerator stops operating.

[Problem to be solved by the invention]

However, in the above configuration, a cold storage plate is simply added in series with the evaporator, so
Although it has the advantage of being easily installed in an existing refrigerator, the refrigerant that cools the cold storage plate has already been evaporated in the evaporator, so the cold storage capacity to freeze the cold storage agent is small and it takes a long time to complete cold storage. It takes. In addition, conventional cold storage plates made of simply flat plates have poor heat exchange efficiency with the air inside the refrigerator, and in order to achieve sufficient cooling performance, it is necessary to increase the heat transfer area of the cold storage plates. Since this results in an increase in the size of the device, mountability becomes a problem.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a regenerator type vehicle refrigerator that has a high refrigerating capacity without increasing the size of the device.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a vehicular refrigeration machine in which a compressor, a condenser, a pressure reducing device, and an evaporator are sequentially connected to form a refrigeration cycle. An evaporation tube of the evaporator that cools the inside of the evaporator, a cold storage pack placed in thermal contact with a gap between the evaporation tubes, and a cold storage pack that is located in the gap between the cold storage packs and connected to the evaporation tubes. The fins are arranged in thermal contact with each other.

[Effect]

According to the above means, the cold storage pack and the fins are arranged alternately in thermal contact with the evaporation tube of the evaporator that cools the inside of the refrigerator, so when the refrigerator is operating, the refrigerant is Due to the heat absorption effect caused by evaporation, the cold storage pack is cooled and frozen, and at the same time, the air inside the refrigerator is heat-exchanged through the fins, cooling the inside of the refrigerator.

On the other hand, when the refrigerator stops operating, the interior of the refrigerator continues to be cooled due to the heat absorption effect caused by the melting of the frozen cold storage pack.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described.

FIG. 1 is a block diagram showing an embodiment of a vehicle refrigerator according to the present invention. It operates by receiving force via an electromagnetic clutch (not shown). 2 is a condenser having a blower fan 2a that liquefies the high temperature and high pressure gas refrigerant discharged from the compressor 1; 3 is a receiver that receives the refrigerant condensed in the condenser 2 and extracts only liquid refrigerant; 4 is a This is an expansion valve that depressurizes and expands the liquid refrigerant drawn out by the receiver 3 into a low-temperature, low-pressure atomized refrigerant.

The expansion valve 4 is a temperature-operated automatic expansion valve that varies the amount of throttling in response to a temperature signal from a temperature sensing cylinder 4a attached to the outlet side piping of the evaporator 5 of the cooling unit 10. The above compressor 1, condenser 2. Receiver 3. Expansion valve 4. The evaporators 5 are connected in this order to form a refrigeration cycle, and the refrigerant flows and circulates in the direction of the arrow in the figure.

FIG. 2(a) shows the configuration of the above cooling unit 10. In the figure, 5a is an evaporation tube constituting the evaporator 5, which is a U-shaped meandering pipe. A cold storage pack 6 made by backing a cold storage agent that freezes at, for example, -5°C with a resin case or the like is placed in thermal contact with the evaporation tube 5a with a gap, and is installed in the evaporation tube 5a. There are many fins 7 in this gap.
are arranged in thermal contact to form a cooling unit IO.

The cooling unit 10 described above is attached to the body 11 using a bracket 21 in contact with the wall of the body 11 and a bracket 22 having the same shape as shown in FIG. 2(b).
The cold storage packs 6 are attached to the evaporation tube 5a in a sandwiched manner, and the bolts 23 are inserted above and below the brackets 21 and 22, and then screwed and tightened to the nuts embedded and fixed in the wall of the body 11. Ru. Note that a drain pan 9 is provided at the bottom of the cooling unit 10 to discharge frost adhering to the cold storage pack 6 and the fins 7 to the outside of the refrigerator when it melts.

FIG. 3(a) is a schematic diagram showing the case where the above-mentioned cooling unit 1-10 is mounted on a vehicle. 2
is mounted on the front upper part of the body 11, and the cooling unit 10 is installed in the refrigerator 8 provided inside the body 11. Note that, as shown in FIG. 3(b), the cooling unit 10 is located inside the refrigerator 8 and is fixed by a guard 12 to be protected from cargo.

Next, the operation of the above embodiment will be explained.

In FIG. 1, compressed refrigerant is condensed in a condenser 2 by the operation of a compressor 1 which is rotationally driven by a vehicle engine (not shown), and is separated into gas and liquid in a receiver 3 to form liquid refrigerant. is sent to the expansion valve 4, where it is decompressed and expanded to become a mist refrigerant, and this atomized refrigerant is evaporated in the evaporator 5 of the cooling unit 10 installed in the refrigerator. is taken away, so the inside of the refrigerator is cooled. Therefore, the cold storage bag 6 placed in thermal contact with the evaporation tube 5a of the evaporator 5 is cooled to the freezing point (for example, -5°C) and frozen, while the evaporation tube 5a is The air inside the refrigerator is directly cooled by the fins 7 placed in contact with the fins 7 .

FIG. 4 shows the surface temperatures of the cold storage packs 6 and fins 7 arranged on the evaporation tube 5a of the present invention, and the cooling unit 10 of the present invention (cool storage packs 6 and fins 7 arranged alternately on the evaporation tube 5a). ) and the internal temperature of the comparative product (
The figure shows the cool-down characteristics for the internal temperature of a cooling unit (based on a cooling unit in which only the cold storage pack 6 is arranged in the evaporation tube 5a) from an outside temperature and an initial internal temperature of 35°C. The cold storage pack 6 with a freezing point of -5° C. was used, and the evaporation tube 5a of the present invention and the comparison product were the same.

As shown in the figure, the fin temperature drops to around -20°C 10 minutes after the start of operation, and then decreases slightly after that, while the temperature in the cold storage bag reaches the freezing point about 2 hours after the start of operation. After that, the temperature is maintained at 15°C for about 2 hours until the entire freezing is completed, and then the supercooling point is reached. The internal temperature of the present invention is -20
It is cooled by heat exchange with the air inside the refrigerator by the fins of 'C, but since the heat capacity of the air inside the refrigerator is much smaller than that of the cold storage panchromator, it decreases faster than the cold storage pack 6 at the beginning of the cooldown. Approximately 30 minutes after the start of operation, the temperature reaches the refrigeration control temperature of 5°C, and then gradually decreases to around 0°C, out of balance with the heat load transmitted through the wall of the body 11.

On the other hand, the internal temperature of the comparison product drops to 15°C approximately 2 hours after the start of operation, and is cooled by heat exchange with the internal air by the cold storage pack 6, so the refrigeration control temperature is 5''C.
It takes about 2 hours to reach this temperature, which is significantly worse than the cool-down performance of the present invention. The reason why the cool-down performance of the refrigerator interior temperature of the present invention is good is due to the cooling effect of the fins 7, which respond at a low temperature that is approximately the same level as the evaporation temperature of the refrigerant in the evaporation tube 5a. This not only improves the cool-down performance when the refrigerator is in operation, but also contributes to the improvement of the cooling performance through a synergistic effect even when the refrigerator is in a cooling state using only the cold storage pack 6 when the refrigerator is stopped.

Next, in this embodiment, the heat exchange between the fins 7 and the air inside the refrigerator is as follows.
Although natural cooling is performed by natural convection, in order to improve the cooling performance, a blower fan may be installed in the refrigerator to blow air onto the surfaces of the fins 7 and the cold storage pack 6 to perform forced cooling by forced convection.

In this embodiment, the cooling unit 10 is installed on one side wall of the body 11, but it may be installed on both side walls, or on the front wall, if necessary.

Further, in this embodiment, a temperature-operated automatic expansion valve is used as the pressure reducing device 4, but a normal constant pressure expansion valve or a capillary may be used as long as it reduces the pressure and expands the refrigerant.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

(a) Since the air inside the refrigerator is cooled in series by the cooling action of the fins that respond at approximately the same temperature as the evaporation temperature of the refrigerant, the refrigerating capacity is high and cooling is fast.

(b) Since the cooling capacity of the cold storage pack is large due to the cooling effect of the fins, there is no need to operate the refrigerator specially like in the past even when the vehicle is stopped for a long time.

(c) Since the structure is such that cold storage packs and fins are arranged alternately on the evaporation tube, the device can be made compact.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of a vehicle refrigerator of the present invention, FIG. 2(a) is a perspective view of a cooling unit of the refrigerator, and FIG. A perspective view showing the installation of the main parts of the
Fig. 3(a) is a schematic side view showing the cooling unit of the refrigerator mounted on a vehicle, Fig. 3(b) is a schematic cross-sectional view of the same, and Fig. 4
The figure is a cool-down characteristic diagram for explaining the operation. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Condenser, 4... Expansion valve (pressure reducing device), 5... Evaporator, 5a... Evaporation tube, 6... Cold storage pack, 7...・Fin, 8...refrigerator.

Claims (1)

[Scope of Claims] In a vehicle refrigerator in which a compressor, a condenser, a pressure reducing device, and an evaporator are sequentially connected to form a refrigeration cycle, the evaporator is installed in a refrigerator of a vehicle and cools the inside of the refrigerator. an evaporation tube, a cold storage pack disposed in thermal contact with the evaporation tube with a gap, and a cold storage pack disposed in the gap between the cold storage pack and in thermal contact with the evaporation tube. A vehicular refrigerator characterized by comprising: