JPH0370963A - Low temperature warehouse - Google Patents

Abstract

PURPOSE:To prevent cooling efficiencies of an evaporator and a cold storage agent from being lowered by forming a cold bypass passage deposed parallely to a cold circulation passage so that cold air cooled by the cold storage agent is fed back to the evaporator and is again led to the cold storage agent. CONSTITUTION:When fan devices 11A, 11B are started, cold air led up to the downstream side of a cold storage agent 12B in an article container part 12 is divided to a cold air stream (a) flowing through a cold air circulation passage P which enters a specification selection chamber 8 from a blow-off outlet 15 and is fed back from a suction inlet 16 again to the article container chamber 12, and to a cold air stream (b) flowing through a cold air bypass passage Q which is fed back to the upstream side of an evaporator 10 through a duct 14, and is cooled by the evaporator 10 and returned to the article container part 12. In this air division, the cold air stream (a) has a larger amount of air, and the cold air can be introduced directly to the evaporator 10 after passing through the cold storage agent 12B substantially without being heat exchanged, whereby temperature rise of the air fed back to the evaporator 10 is suppressed. Accordingly, heat exchange capacity of the evaporator 10 is not lowered and the air is blown off to the cold storage agent 12B as low temperature cold air, so that cooling efficiency by the cold storage agent 12B can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] Industrial Application Field The present invention relates to a low-temperature refrigerator that can simultaneously freeze a cold storage agent and cool the interior of the refrigerator.

Conventional technology The main body of the cold storage box consists of a cold storage chamber containing a built-in cold storage agent, a defrosting heater, and an air supply fan, and a cold storage chamber for keeping transported goods such as food cool, and a cooling chamber that partitions the cold storage chamber and the cold storage chamber into a ventilation hole. Japanese Patent Application Laid-Open No. 102269/1989 describes a cold storage type cold storage which includes a heat insulating partition wall in which a ventilation fan is arranged and a refrigerator unit installed outside the cold storage chamber side of the cold storage main body. In this publication, ventilation holes are formed at two locations in a heat-insulating partition wall.

Problems to be Solved by the Invention In the above-mentioned conventional technology, the cold storage agent is cooled and frozen by air cooled through an evaporator, and the cold air that has passed through the cold storage agent is guided into the cold storage chamber through a ventilation fan and a vent hole. However, since all the cold air that has passed through the cold storage agent is led to the cold storage room and then returned to the cold storage room, the temperature of the cold air that returns to the evaporator tends to rise due to cooling in the cold storage room, so the air in the evaporator is There is a problem in that the temperature on the inlet side tends to be high, which substantially reduces the cooling efficiency of the evaporator and the regenerator.

Accordingly, the present invention provides a low-temperature refrigerator provided with a cold air bypass path that returns air that has passed through the cold storage agent directly to the air inlet side of the evaporator.

[Structure of the invention]

Means for Solving the Problems The present invention provides a low-temperature refrigerator in which a cold storage agent is frozen with cold air cooled by an evaporator, and a cold air circulation path is formed in which the cold air cooled by the cold storage agent is forcedly circulated inside the refrigerator using a blower. A cold air bypass path is formed in parallel with the cold air circulation path so that the cold air cooled by the cold storage agent returns to the evaporator and is again guided to the cold storage agent. However, the cold air that has passed through the cold storage agent is returned directly to the evaporator, thereby reducing the temperature difference between the air leaving the evaporator and the air returning to the evaporator.

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

1 is a refrigerator serving as a low-temperature storage; in this example, it is a refrigerator for transportation called a cold roll box, which is used when transporting goods while cooling them on a transport vehicle such as a truck. This will be explained using an example.

The refrigerator 1 is equipped with wheels 2 for movement at its bottom, has a heat insulating box 4 with an opening 3 formed on the side, and a heat insulating door 5 that opens and closes the opening 3, and has a partition inside. A freezing room 7 and a specification selection room 8 as a storage room are partitioned by a board 6.

The freezing chamber 7 is provided with an article storage section 12 as a cold storage agent storage section that stores an evaporator 10, a plurality of air blowers 11, and a cold storage agent 12B. It consists of two driven evaporator blowers 11A and one refrigerator air circulation blower 11B driven by a DC power source. The amount of air blown by each of the air blowers 11A and IIB is set to be approximately the same. Further, along one wall of the freezing chamber 7, that is, the ceiling wall 13, a duct 14 is arranged, which has one end opened on the leeward side of the article storage section 12 and the other end opened on the windward side of the evaporator 10, and is used for cold air circulation as described below. A cold air bypass path Q is formed in parallel with the path P.

Reference numeral 15 indicates an air outlet formed in a portion of the partition plate 6 located on the leeward side of the article storage section 12, and reference numeral 16 indicates a suction port formed in the partition plate 6 in correspondence with the blower device 11B for internal air circulation. A cold air circulation path P is formed in which the cool air that has passed through the cool storage agent 12B of the article storage section 12 is guided into the specification selection chamber 8 from the blow-off port 15 and returned to the article storage section 12 through the suction port 16.

The evaporator side part of the internal air circulation blower 11B is designed not to suck in the air that has passed through the evaporator, and also to move the air from the specification selection chamber 8 sucked in from the suction port 16 to the evaporator side. A partition plate 17 is provided to prevent this from occurring. In addition, since the air capacity of each blower device 11A and IIB is made the same, the amount of air sucked in from the suction port 16 by the air blower device 11B for internal circulation and the amount of air guided to the air inlet side of the evaporator 10 via the duct 14. The ratio of the amount of air drawn is 1:2, and the latter amount of air can be increased.

Reference numeral 18 denotes an inner door made of a transparent material that opens and closes the article entrance formed on the front surface of the article storage section 12.

A machine room 20 houses a compressor, a condenser, a blower for the condenser, and the like.

30 sets the temperature inside the specification selection chamber 8 to the freezing temperature (for example, -10°
The operation unit serves as a temperature setting unit that selects any temperature among the following: ice temperature (approximately -5°C to 0″C), and refrigeration temperature (approximately 0°C to 10°C); This operation section 30
Based on the selection state by
Controls the operation and stopping of B.

The temperature control section T includes a freezing thermostat 31 that maintains the freezing temperature in the specification selection room s at, for example, -15°C, and an ice temperature thermostat 32 that maintains the freezing temperature at, for example, 0°C.
・Prepare three refrigeration thermostats 33 that maintain the refrigeration temperature at, for example, 5°C, select one of the thermostats by a selection operation using the operation unit 30, and enter the specification selection room 8.
maintain the temperature according to your choice.

A freezing chamber temperature controller is disposed in the article storage section 12, and the operation of the compressor is stopped when the temperature reaches a predetermined temperature, for example, -25°C or lower. It should be noted that the evaporator blower is operated continuously.

In addition, although this example shows an example in which the temperature control section T is configured with a thermostat, a thermistor is arranged in each of the freezing chamber 7 and the specification selection chamber 8, and the detection signal from each thermistor and the set temperature by the operation section are (Specifically, depending on any one of freezing, refrigeration, and ice temperature), the operation and stopping of the compressor and the internal circulation blower 11B may be controlled.

Based on the above configuration, cooling of the freezing chamber 7 and the specification selection chamber 8 will be explained next. However, freezing room 7 and specification selection room B
Assume that the inside is not cooled.

When the freezing temperature is selected using the operation unit 30, the freezing thermostat 31 is selected by this selection operation (
(see Figure 6), and a cooling operation switch (not shown)
When is pressed, the compressor/both claw feeding devices 11A and IIB start operating. Therefore, the inside of the article storage section 12 is gradually cooled by the air cooled through the evaporator 10, and the cold storage agent 12B is frozen.

At this time, the cold air guided to the leeward side of the cold storage agent 12B in the article storage section 12 enters the outlet 15 or the specification selection chamber 8 and returns to the article storage chamber 12 from the suction port 16, that is, the cold air circulation path P. (hereinafter referred to as cold air flow <A>), returns to the windward side of the evaporator 10 via the duct 14, is cooled by the evaporator 10, and returns to the article storage section 12, that is, the cold air bypass path Q. Things that flow (hereinafter referred to as cold air currents)
(referred to as A)).

Moreover, 4. In this branching, as mentioned above, the amount of air in the cold air flow (a) is large, and after passing through the cold storage agent 12B, the cold air can be directly introduced into the evaporator 10 without being subjected to heat exchange. This suppresses the temperature rise of the air returning to the vessel 10. Therefore, without reducing the heat exchange capacity of the evaporator 10, it is possible to blow cold air at a lower temperature onto the regenerator 12B, improving the cooling efficiency of the regenerator 12B, compared to the conventional forced convection type. The time required to freeze the cold storage agent can be shortened.

It is the internal circulation blower 11B that generates the cold air flow (A), and this cold air flow (A) gradually cools the inside of the specification selection chamber 8, and the refrigeration thermostat 3
The open operating temperature of 1 (in this example, 1°C lower than 15°C)
If the temperature drops below 6℃, the thermostat 3 will turn off.
1 contact is open and the internal circulation air blower 11B
operation is stopped, and the forced cold air convection in the specification selection chamber 8 is stopped (there is still some cold air entering the specification selection chamber 8 by natural fall from the air outlet 15).

As the forced convection of cold air in the specification selection chamber 8 is stopped, forced cooling in the specification selection chamber 8 is no longer performed, and the temperature gradually rises until it exceeds the return operating temperature of the thermostat 31 (-14°C in this example). When this happens, the contact of the thermostat 31 closes, and the internal circulation blower 11B starts operating again to cool the specification selection chamber 8 by forced convection.The above-mentioned operation is repeated until the specification selection chamber 8 reaches the set temperature. to be maintained.

Note that when the ice temperature or refrigeration temperature is selected using the operation unit 30, "freezing temperature and for freezing" in the above operation is replaced with 1 ice temperature and ice temperature, or "refrigeration temperature and refrigeration". It can be assumed that it operates as described above, and the explanation will be omitted.

On the other hand, since cold air is led from the outlet side of the article storage section 12 through the duct 14 to the air inlet side of the evaporator 10,
This duct 14 acts as a bypass passage for cold air and promotes cooling of the article storage section 12. In addition, the relative humidity of the cold air that returns to the evaporator 10 via the duct 14 is lower than that of the cold air that returns to the article storage section 12 via the storage room 8, so the amount of frost formed on the evaporator 1o per unit time is reduced. Therefore, the number of times of defrosting can be reduced. In particular, if the cold air flow rate according to (a) is made larger than the cold air flow rate according to (a), the article storage section 12
And cooling of the cool storage agent 12B is promoted.

In addition, when the article storage section 12 is gradually cooled down to below the opening operation temperature of the freezing chamber temperature controller (in this example, it is set at -26°C), the contact of the temperature controller opens and the compression Since the operation of the machine is stopped, cooling of the freezing chamber 7 is stopped. Note that the evaporator blower 11A continues to operate. Since the refrigerant supply to the evaporator 10 is stopped by stopping the compressor, overcooling of the freezing chamber 7 can be prevented.

Then, the return temperature of the freezing room temperature controller (in this example, -24
°C), the contacts of the temperature regulator are closed and the compressor is operated again to cool the freezing chamber. Thereafter, the above-described operations are repeated to cool and maintain the freezing chamber 7 at the set temperature.

〔Effect of the invention〕

As described in detail above, according to the present invention, the cold storage agent can be frozen using the cold air cooled by the evaporator, and the cold air cooled by the cold storage agent can be forcedly circulated through the refrigerator using only the cold air circulation path. By forming a cold air bypass path that directly returns to the evaporator and leads back to the cold storage agent, it is possible to suppress the rise in temperature of the air returning to the evaporator, and reduce the temperature of the cold air blown to the cold storage agent. This makes it possible to accelerate the freezing of the cold storage agent.

[Brief explanation of drawings]

Each figure shows an embodiment of the present invention. Figure 1 is a longitudinal cross-sectional view showing the flow of cold air in the freezing chamber, Figure 2 is an external side view of the low-temperature refrigerator, and Figure 3 is a cross-sectional view of the freezing chamber. , Figures 4 and 5 are cross-sectional views of Figure 3 A-A and B with the top wall attached.
-B sectional view and FIG. 6 are control circuit diagrams for controlling operation and stop of the internal circulation blower. 1... Low temperature storage, 7... Freezing room, 8... Storage room, 12B... Cold storage agent, 14... Duct,
15...Air outlet, 16...Suction port, P...
Cold air circulation path, Q...cold air bypass path.

Claims (1)

[Claims] 1. A cold air circulation path is formed in which a cold storage agent is frozen with cold air cooled by an evaporator and the cold air cooled by the cold storage agent is forcedly circulated inside the warehouse using a blower, in which the cold air cooled by the cold storage agent is A low-temperature refrigerator characterized in that a cold air bypass path is formed in parallel with the cold air circulation path so that the cold air returns to the evaporator and is guided to the cold storage agent again.