JPH0391676A - Low temperature box - Google Patents

Abstract

PURPOSE:To control a temperature in a low temperature box even in the freezing time period of a cold accumulating agent, and select the controlled temperature in accordance with the temperature of a stored article to be held cold by cooling a storage chamber by the cold accumulating agent for freezing the article to the temperature set by a setting unit. CONSTITUTION:A storage chamber is enabled to be cooled by a cold accumulating agent 12B for freezing an article to a temperature in the range of a plurality of temperature capable of being set thereto by a setting unit. A first temperature controller 53 acts to maintain the temperature of a storage chamber 8 to a value set by the setting unit and a second temperature controller 73 acts as a protecting device for checking a supercooling when the temperature of the storage chamber 8 tends to fall below the set value by some cause. Further, the second temperature controller 73 and a heater 76 for preventing the supercooling act cool the storage chamber by the cold accumulating agent 12B in correspondence with both a temperature at which an article is frozen, namely, a freezing temperature and a temperature at which the article is not frozen, namely, an ice temperature and a cold storage temperature. Thus, the article can be kept as cooled by the latent heat of fusion of the cold storage agent 12B to within a freezing temperature range or in an ice temperature or cold storage temperature range.

Description

[Detailed description of the invention] [Purpose of the invention] Industrial applications The present invention relates to a low temperature refrigerator equipped with a cooling device and a cold storage agent.

Conventional technology In which a cold storage body containing a cold storage agent is attached to a cooler for heat transfer, there are 1) Japanese Utility Model Publication No. 60-614 and 2) Japanese Unexamined Patent Publication No. 62-210369.

In the technology (2), in order to improve the efficiency of heat transfer from the cooler to the cold storage agent, a heat transfer member made of a heat conductive material, a container attached to the heat transfer member, and a container inside the container are used. The stored cold storage agent constitutes a cold storage body.

On the other hand, in the technology (2), when the cooler is operating, the cold storage agent is frozen and the inside of the refrigerator is cooled, and when the cooler is stopped, the inside of the refrigerator is cooled by the latent heat of melting of the frozen cold storage agent.
A refrigerator has been disclosed in which a compressor continues to be driven and a cooler performs a cooling operation until a cold storage agent is frozen, regardless of the operation of an internal temperature regulator.

Problems to be Solved by the Invention In the technique (2) above, when the compressor operation is stopped, such as at night, the temperature rise in the storage room is suppressed by the latent heat of melting of the cold storage agent that is frozen while the compressor is operating. However, it is not a temperature control that corresponds to the cooling set temperature of the storage room, but is only intended to suppress the temperature rise when the compressor is stopped. There was a problem in that it was not possible to control the temperature according to the difference in temperature.

In the technique (2) above, the compressor is driven regardless of the operation of the refrigerator temperature controller until the cold storage agent freezes, so the temperature inside the refrigerator cannot be controlled during this period. The problem was that I couldn't do it. Moreover, if a cold storage agent with a low freezing temperature is used, the temperature inside the warehouse will be below 0°C during the freezing period, and the product will remain in a temperature range where it will not freeze, that is, a refrigerated temperature range or freezing temperature range. It was not possible to freeze the cold storage agent.

Therefore, the present invention provides a low-temperature refrigerator in which the temperature inside the refrigerator can be controlled even during the freezing period of the cold storage agent, and the control temperature can be selected in accordance with the cold storage temperature of the stored articles.

[Structure of the invention]

Means for Solving the Problems The low-temperature refrigerator of the present invention includes a storage chamber in which articles are stored and air cooled by the latent heat of melting of a cold storage agent circulates, and a cold storage agent that allows articles to be frozen using the latent heat of melting of the cold storage agent. a cooling device that freezes the storage room; a setting section that sets the storage room to either a temperature zone where the articles freeze or a temperature zone where the articles do not freeze; and a section that controls the operation of the circulating air blower based on the setting of the setting section. 1
a temperature control device; and a second temperature control device that controls energization of the supercooling prevention heater at a temperature lower than the setting of the setting section, and the setting section sets the temperature of the storage room using a cold storage agent for freezing articles. This allows cooling to be performed in multiple temperature ranges that can be set.

Function: The first temperature control device acts to maintain the temperature of the storage chamber at the temperature set in the setting section, and the second temperature control device acts to maintain the temperature of the storage chamber at the temperature set by the setting section, and the second temperature control device acts to maintain the temperature of the storage chamber at the temperature set by the setting section. Acts as a protective device to prevent cooling. Also, with this second temperature control device and the overcooling prevention heater,
The cold storage agent for freezing the articles acts to cool the inside of the storage room in accordance with both the temperature at which the articles freeze, that is, the freezing temperature, and the temperature at which the articles do not freeze, that is, the ice temperature and the refrigeration temperature.

Example Next, an embodiment of the low temperature refrigerator will be described based on the drawings.

Reference numeral 1 denotes a low-temperature storage, which will be explained by taking as an example a low-temperature storage called a cold roll box that is used when transporting articles while cooling them on a transport vehicle such as a truck.

The low-temperature refrigerator 1 is equipped with wheels 2 for movement at its bottom, has an insulating box 4 with an opening 3 formed on its side, and an insulating door 5 that can open and close the opening 3, and inside thereof, A freezing chamber 7 separated by a partition plate 6 and a specification selection chamber 8 serving as a storage chamber are arranged.

In the freezing chamber 7, an evaporator 101 as a cooling device, a plurality of air blowers 11, and an article storage g12 as a cold storage agent storage section for storing a cold storage agent 12B are arranged. It consists of two evaporator blowers 11A driven by a DC power source 30 and one refrigerator air circulation blower 11B driven by a DC power supply 35 or 50. The amount of air blown by each of the air blowers 11A and IIB is set to be approximately the same. Also, one wall of the freezing chamber 7, that is, the ceiling wall 13
A duct 14 having 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 is arranged along the duct 14,
A cold air bypass path P is formed in parallel to a cold air circulation path Q, which will be described later.

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 Q 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 B from the Suita 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 evaporation FSJO, 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 11B is the same, the air blower device 11B for internal circulation is connected to the suction port 1.
6 and the evaporator 10 via the duct 14.
The ratio of the amount of air guided to the air inlet side is approximately 1:2, and the latter, that is, the amount of air passing through the cold air bypass path P 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.

Next, the operation control device K of the low-temperature refrigerator will be explained based on FIG. 1.

L is an AC circuit section, M is a DC circuit section, 30 is a three-phase AC power source, and 34 is a compressor drive motor connected to power supply lines 31 to 33.

35 is an AC-DC converter as a charger that converts AC into DC and obtains a voltage for charging a storage battery 50 which will be described later; 36 is a first relay coil; 37 is an evaporator blower 1
1A AC fan motor, 38 is the AC fan motor of the condenser blower, 39.40 is the magnet coil 52C
They are a first switch and a second switch.

41 detects the temperature inside the article storage section 12, controls the operation/stop of the compressor drive motor 34 based on the detected temperature, and adjusts the article storage section 12 in the freezing chamber 7 to a freezing temperature (for example, - In this example, two types of cold storage agents with different freezing temperatures are used (one with a freezing temperature of 125°C and the other with a freezing temperature of 15°C), and the former is used for freezing. Either one of the cold storage agent (the latter is referred to as a cold storage agent for ice-temperature refrigeration) is stored in the article storage chamber 12, and the temperature in the article storage section 12 is set at a plurality of levels according to the freezing temperature of the selected cold storage agent. temperature can be controlled. In other words, 42 is a temperature (io"c lower than the freezing temperature (-25°C) of the cold storage agent for freezing).
A first thermostat 43 controls the inside of the article storage section 12 to 10 degrees below the freezing temperature of the cold storage agent (-5°C) in order to freeze the cold storage agent for ice-temperature refrigeration.
A second thermostat 44 is connected in series to the first thermostat 42 and controls a second relay coil 6o which will be described later; 45 and 46 are switches connected in parallel to each other and the second These are switches connected in series to the thermostat 42, and correspond to a third relay coil 61 and a fourth relay coil 62, respectively, which will be described later. Note that the evaporator 1o allows cooling to below -36°C.

The DC circuit section M is connected to the output side of the AC-DC converter 35, and 5o is a rechargeable storage battery connected to the AC-DC converter 35 via the switch 51 of the first relay coil 36. .

Reference numeral 52 indicates the temperature within the specification selection chamber 8 at which the stored items freeze, that is, the freezing temperature (for example, -10"C or lower), or the temperature that is 0°C or lower and just before freezing the stored items, that is, the freezing temperature (-5" C or lower). °
c-o”c) / Refrigeration temperature (about 1°C to 10°C)
It is a temperature setting section that selects an arbitrary temperature among the
Based on the setting state by this setting section 52, the specification selection room 8
A storage room temperature control unit 53 as a first temperature control device placed at a proper location inside the storage room is operated to control operation and stop of the internal circulation air blower 11B to control the amount of air blown per unit time. 57 is a DC fan motor, 58 is a DC fan motor 5
This is a controller for controlling the rotation speed and rotation direction of 7. However, in this embodiment, the controller 58 rotates the fan motor 57 in the same direction and at the same rotation speed.

The storage room temperature control section 53 includes a freezing thermostat 54 that maintains the freezing temperature in the specification selection room 8 at, for example, -15°C, and a freezing temperature as a second temperature higher than the first temperature, such as 0°C. Thermostat for maintaining ice temperature 5°5・
Three refrigeration thermostats 56 are prepared to maintain a refrigeration temperature as a third temperature higher than the second temperature, for example, 5°C, and any one of the thermostats is selected by the setting operation by the setting unit 52, Specifically, the circulating air blower 11B1 controls the amount of air blown and maintains the temperature of the specification selection chamber 8 according to the setting.

Reference numeral 59 connects the storage room temperature control section 53 to the internal circulation air blower 11.
A group of relays connected in parallel to the series circuit with B, 60 is a second relay coil corresponding to the freezing thermostat 54, 61 is a third relay coil corresponding to the ice temperature thermostat 55, and 62 is a relay group connected in parallel to the series circuit with B. Refrigeration thermostat 5
This is the fourth relay coil corresponding to No. 6.

7L and 72 are switches corresponding to the third relay coil 61 and the fourth relay coil 62, respectively, and 73 is a heater 76 for preventing overcooling, which is arranged in the specification selection chamber 8 and will be described later (configuring the specification selection chamber 8). This is a supercooling temperature control unit as a second temperature control device that controls energization/de-energization of the (disposed on the wall surface). This supercooling temperature control section 73 is connected in series to the switch 71, and when the setting section 52 selects the freezing temperature (zero "C" in this example), the supercooling temperature control section 73 is operated for some reason (for example, when a refrigerating agent is put in). Even if the temperature becomes lower than this freezing temperature due to chilling out, the outside temperature becomes low, etc., the temperature (this example is 0°C) is lower than the freezing temperature (0°C in this example) by a predetermined temperature (4°C in this example). An overcooling prevention thermostat 74 for ice temperature that prevents the ice temperature from dropping below -4°C (in this example, 5°C) is connected in series to the switch 72, and
) and a supercooling prevention thermostat 75 for preventing the temperature from falling below a predetermined temperature (in this example, 1° C.).

In addition, although this example shows an example in which each temperature control section 41, 53, 73 is configured with a thermostat, a thermistor is placed in each of the freezing compartment 7 and specification selection compartment 8, and detection signals and settings from each thermistor are provided. The compressor drive motor 34, the internal circulation blower 11B, and the supercooling prevention heater 76 are controlled depending on the relationship with the temperature set by the section 52 (specifically, any one of freezing, refrigeration, and ice temperature). The operation and stopping may be controlled.

Cooling of the freezing chamber 7 and the specification selection chamber 8 will be explained based on the above configuration. However, it is assumed that both chambers 7 and 8 are in a non-cooled state.

A cold storage agent for ice-temperature refrigeration is stored in the article storage section 12 and the setting section 5
If the ice temperature is selected by step 2, the ice temperature thermostat 55 is selected by this selection operation. Then, when the cooling operation switch (not shown) is pressed or the power plug is inserted into the socket (both not shown), the first relay coil 36 is energized, the switch 51 is closed, and the storage battery 5
0 charging and circulating air blower 11B and the third relay coil 61 are energized, the magnet coil 52C is energized, the compressor drive motor 34 and the AC fan motor 37, 38 are energized, and each starts operating. do. 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. Further, the interior of the specification selection chamber 8 is gradually cooled by the latent heat of melting of the cold storage agent 12B by operation of the circulating air blower 11B.

The open operating temperature of the thermostat 55 (-1°C in this example)
(set to ) or below, the contact opens, the circulation blower 11B stops, and forced cold air convection inside the refrigerator is stopped.

Since the cold forced convection in the specification selection chamber 8 is stopped, forced cooling in the specification selection chamber 8 is not performed, and the temperature gradually rises. When the temperature reaches the return operation temperature of the thermostat 54 (1°C in this example), the contact of the thermostat 55 closes, the internal circulation blower 11B starts operating again, and the specification selection chamber 8 is cooled by forced convection. . Thereafter, the above-described operation is repeated to maintain the specification selection chamber 8 at the freezing temperature.

On the other hand, due to some reason, for example, the ice temperature thermostat 55 does not operate and the circulating air blower 11B continues to operate, a freezing cold storage agent is put into the storage unit 12 instead of an ice temperature cooling cold storage agent, or the outside temperature If the temperature inside the specification selection room 8 is low, such as below freezing, the temperature inside the specification selection room 8 may be lower than the set temperature (0°C in this example).
), the room closing operating temperature of the ice temperature supercooling prevention thermostat 74 (in this example, the
°C), the contact closes and the overcooling prevention heater 76 is energized, heating by the heater 76 gradually warms the inside of the specification selection chamber 8. When the temperature rises above the return operation temperature of the thermostat 74 (in this example, it is set at -1°C), the contacts of the thermostat 74 open, stopping the energization of the overcooling prevention heater 76, and
Stop heating inside. Thereafter, the above-described operations are repeated to prevent the temperature inside the specification selection chamber 8 from dropping by a predetermined temperature or more below the set temperature.

In addition, the article storage section 12 is gradually cooled, and the opening operation temperature of the second thermostat 43 (in this example, it is set at -16 degrees Celsius).
below, the contact opens and the compressor drive motor 34
is stopped, cooling of the freezing chamber 7 is stopped, and overcooling of the freezing chamber 7 is prevented. However, the evaporator blower 11A continues to operate because the AC fan motor 37 is energized. When the temperature inside the article storage chamber 12 gradually rises due to the stoppage of cooling and reaches the return temperature of the second thermostat 43 (set at -14°C in this example), the contact closes and the compressor starts operating again. is driven to cool the freezing chamber 7.The above-mentioned operation is then repeated to bring the interior of the article storage chamber 12 to a temperature lower than the freezing temperature of the ice-temperature refrigerant (in this example, -15°C).
℃).

In addition, when the freezing temperature or refrigeration temperature is set by the setting unit 52, the phrase ``1 freezing temperature and freezing temperature'' in the above-mentioned operation may be replaced with 1 freezing temperature and ``1 freezing temperature'' or ``
It can be considered that the phrase "refrigerating temperature" and "for refrigeration" operate, and the explanation thereof will be omitted. However, frozen
Since the temperature relationship is ice-warm and refrigerated, the operating temperatures of the thermostats 54 to 56 are different, and the higher the set temperature, the shorter the time it takes to stop the blower 11B, and as a result, the amount of air blown decreases. . Furthermore, since the cold air is guided from the outlet side of the article storage section 12 to the air inlet side of the evaporator 10 via the duct 14, this duct 14 acts as a bypass passage for the cold air, and also passes through the specification selection chamber 8. The evaporator 1 has a lower relative humidity than the air passing through the specification selection chamber 8 in order to return to the evaporator 10 without
0, the amount of R frost per unit time to the evaporator 10 decreases, and the number of times of defrosting can be reduced.

In addition, when the freezing cold storage agent is stored in the article storage section 12 and the freezing temperature is set in the setting section 52, the second thermostat in the above operation description regarding the freezing chamber is replaced with the first thermostat. It can be thought of as something that operates, and its explanation will be omitted.

According to the configuration described above, the cooling device freezes the cold storage agent and cools the storage room using the latent heat of melting of the cold storage agent, and the temperature control device also controls the circulating air blower based on the setting of the setting section. Since the amount of air blown is controlled, the temperature in the storage room can be controlled even while the cold storage agent is freezing. In addition, one low-temperature storage can be used in multiple temperature zones, and when used for transportation on a transport vehicle, it can be used depending on the type of goods stored in the storage room and the storage temperature. , it is possible to improve usability as a low-temperature refrigerator. Furthermore, since it is equipped with a heater to prevent supercooling, even if the temperature inside the storage room tends to drop below the set temperature for some reason, the temperature will not drop below the set temperature by more than a predetermined temperature, and the goods will not be cooled down due to supercooling. It is possible to prevent the cells from freezing and causing cell destruction, thereby suppressing the quality deterioration of the product due to supercooling. If the set temperature is set to a temperature range in which items do not freeze, and if a freezing cold storage agent is stored as a cold storage agent, the temperature in the storage room is likely to drop, but the overcooling prevention heater can suppress overcooling. The freezing cold storage agent also makes it possible to keep the inside of the storage room cooled to a temperature at which articles do not freeze, and it is possible to increase the storage room temperature control range when selecting the freezing cold storage agent.

〔Effect of the invention〕

As described in detail above, according to the present invention, the cooling device performs freezing operation of the cold storage agent, and the first and second temperature control/devices control the amount of air blown based on the settings of the setting section, while the storage Temperature can be controlled. Therefore, the latent heat of fusion of the cold storage agent makes it possible to cool and preserve the article in a freezing temperature range, an ice temperature range, or a refrigerated temperature range.

In addition, since it is equipped with a heater to prevent overcooling, even if the temperature inside the storage room tends to drop below the set temperature for some reason, especially when trying to maintain the temperature at refrigeration or ice temperature, the temperature will be lower than the set temperature. The product is not cooled to a temperature lower than or equal to the temperature, and quality deterioration of the product such as cell destruction due to continued supercooling can be suppressed, and the usability of the low-temperature refrigerator and temperature control accuracy can be improved.

[Brief explanation of drawings]

Each figure shows an embodiment of the present invention, and FIG. 1 is an operation control device for a low-temperature refrigerator, FIG. 2 is a perspective view of a low-temperature refrigerator, FIG. 3 is a cross-sectional view of a freezing chamber, and FIGS. 4 and 5. The figures are a sectional view taken along line AA and line BB in FIG. 3 with the top wall attached. DESCRIPTION OF SYMBOLS 1...Low temperature storage, 7...Freezing room, 8...Storage room, 10...Cooling device, 11B...Circulating air blower, 12...Goods storage section, 12B...Cold storage agent,
52... Setting section, 53... First temperature control device,
73...Second temperature control device, 76...Heater for overcooling prevention. Figure 2 U Figure 3 Figure 4

Claims (1)

[Claims] 1. A storage room in which articles are stored and air cooled by the latent heat of melting of the cool storage agent circulates; a cooling device that freezes the cool storage agent so that the articles can be frozen with the latent heat of melting of the cool storage agent; a setting section that sets the chamber to either a temperature zone where the article freezes or a temperature zone where the article does not freeze; a first temperature control device that controls the operation of the circulating air blower based on the setting of the setting section; and the setting section. a second temperature control device that controls energization of the overcooling prevention heater at a temperature lower than the temperature set by the setting unit, and a second temperature control device that controls energization of the heater for overcooling prevention at a temperature lower than the setting of the setting unit; A low-temperature refrigerator characterized by cooling.