JPH087000B2 - Refrigerator operation control method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the operation of a refrigerator, and more specifically, in a constant temperature and high humidity refrigerator using brine as a cooling medium, the ambient temperature of the refrigerator is lower than the preset temperature in the refrigerator. ,
When a large amount of frozen food is stored in the refrigerator, it effectively suppresses the temperature drop in the refrigerator and maintains the refrigerator temperature slightly lower than the set temperature in the refrigerator, resulting in deterioration of freshness of the food. However, the present invention relates to an operation control method capable of performing cold storage in a good state.

Conventional technology The vaporized refrigerant compressed by the compressor is liquefied by the condenser, the liquefied refrigerant is dehumidified by the dryer, the pressure is reduced by the capillary tube, and then the vaporized vapor is evaporated in the evaporator to remove the heat of vaporization. A refrigerating system for cooling the surroundings is known, and in a refrigerator used in a general household or the like, foodstuffs in the refrigerator are cooled by the evaporator arranged in the refrigerator. The temperature inside the storage is maintained within the range of the upper limit set temperature and the lower limit set temperature by the inside temperature detection device.

Further, in the storage, fresh food such as fruits, vegetables, meat and fish is frozen and stored for a long period of time, and in order to gradually thaw the frozen food, a refrigerator having the evaporator as a cooling source is not sufficient, It is necessary to manage the inside of the refrigerator in a constant temperature and high humidity state in order to suppress the temperature change in the refrigerator as much as possible and prevent the evaporation of water from food. As a means for responding to this demand, a constant temperature and high humidity refrigerator using brine (antifreeze) as a cooling medium has been put into practical use. In this, the brine in the brine tank is cooled by an evaporator that constitutes the refrigeration system, and the cooled brine is circulated through a cooler arranged in the refrigerator to cool foods and the like. This brine-cooled refrigerator has a large cooling capacity because a large amount of brine with a large specific heat is circulated compared to a normal refrigerator that uses an evaporator as a cooling source, and therefore, it can be used for cooling and storing a large amount of food. Is suitable. Moreover, since the difference between the surface temperature of the cooler and the temperature inside the refrigerator can be made small, it is possible to prevent moisture in the air inside the refrigerator from condensing on the surface of the cooler to form frost, and keep the inside of the refrigerator in a high humidity state. can do.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the above-described refrigerator, the refrigeration system is operated at the upper limit set temperature of the inside temperature detection device to cool the inside of the refrigerator, and the refrigeration system is controlled to be stopped at the lower limit set temperature to control the refrigerator. The internal temperature is maintained within the upper and lower set temperature range. However, in the refrigerator, although the heat of the outside is prevented from entering the storage box by the heat insulating material, if there is a large temperature difference between the inside of the refrigerator and the outside air, the heat inevitably occurs. Similarly, opening and closing of the door causes heat penetration. Therefore, when the outside air temperature is higher than the set temperature in the refrigerator, the temperature in the refrigerator rises due to the above-mentioned heat intrusion, but in this case, the heat load is handled by operating the refrigeration system.

By the way, when the temperature of the outside air is lower than the set temperature in the cold storage, the temperature inside the cold storage lowers due to negative heat penetration. Further, when frozen foods are widely distributed as in the present situation, a large amount of frozen foods may be stored in the refrigerator, and in this case also, the frozen foods are used as a kind of cooling source to lower the temperature in the refrigerator. When the temperature inside the refrigerator drops in this way, there is a problem that it becomes difficult to store the foodstuffs in the refrigerator at the optimum temperature due to overcooling and deterioration due to freezing, or rupture of the liquid container. . In particular, when the refrigerator is used in a severe cold season or when it is used in a cold area, the above-mentioned problems occur remarkably.

OBJECT OF THE INVENTION The present invention has been proposed to preferably solve this problem in view of the above-mentioned problems that may occur when storing a frozen food or using a refrigerator in the above-mentioned severe cold season or in cold regions. An object of the present invention is to provide a method capable of suppressing a decrease in internal temperature due to a decrease in outside air temperature, storage of frozen foods, etc., and keeping food materials in a good condition.

Another object of the present application is to suitably control the inside temperature so that when the inside temperature falls below the lower limit set temperature, the lower limit set temperature becomes an average temperature.

Means for Solving the Problems To overcome the above-mentioned problems and to suitably achieve the intended purpose, the operation control method for a refrigerator according to the present invention includes a evaporator in a brine tank which constitutes a part of a refrigeration system. The brine is cooled, the cooled brine is circulated through a cooler arranged in the storage compartment to cool the interior, and an internal temperature detection device arranged at an appropriate place in the storage compartment is set to the upper limit of the storage compartment. When the second set temperature related to the temperature is detected, the operation of the refrigeration system is started,
When the first set temperature related to the lower limit temperature in the cold storage is detected, the operation of the refrigeration system is stopped, and when the internal temperature detection device detects a predetermined drop in the cold storage temperature, the heating means arranged in the cooler. In a refrigerator configured to heat brine that circulates in a cooler or defrost the cooler by operating the refrigerator, the inside temperature detection device opens at a first set temperature that is a lower limit temperature inside the refrigerator. At the same time, a first contact point that closes at a second set temperature that is the upper limit temperature in the refrigerator, and a second contact point that opens at the first set temperature and closes at a third set temperature that is a predetermined temperature lower than the first set temperature. And a contact point, and during the cooling operation in which the operation of the refrigeration system is controlled as described above, the in-compartment temperature detection device detects a third set temperature lower than the first set temperature by a predetermined value. Then,
When the second contact is closed to start the heating by the heating means, and when it is detected that the internal temperature has risen to the first set temperature, the second contact is opened to stop the heating by the heating means. It is characterized in that it is controlled.

Further, a refrigerator operation control method according to another invention of the present application, a brine in a brine tank is cooled by an evaporator forming a part of a refrigeration system, and the cooled brine is used as a cooler arranged in a storage. The inside of the refrigerator is circulated to cool the inside of the refrigerator, and when the second set temperature related to the inside upper limit temperature is detected, the operation of the refrigeration system is started, and when the first set temperature related to the inside lower limit temperature is detected, the operation of the refrigeration system is stopped. When the internal temperature detection device detects a predetermined decrease in internal temperature, the heating means provided in the cooler is operated to heat the brine circulating in the cooler or defrost the cooler. In the refrigerator configured to perform the above, the inside temperature detection device has a first contact point that opens at a first set temperature that is a lower limit temperature inside the refrigerator and closes at a second set temperature that is an upper limit temperature inside the refrigerator. A predetermined temperature from this first set temperature The second closed at a third set temperature, which is lower than the first set temperature (T ₁ ), and a fourth set temperature that is higher than the first set temperature (T ₁ ) by a predetermined temperature and lower than the second set temperature which is the upper limit set temperature.
And a contact point, and during the cooling operation in which the operation of the refrigeration system is controlled as described above, the in-compartment temperature detection device detects a third set temperature lower than the first set temperature by a predetermined value. Then,
When the second contact is closed to start heating by the heating means, and when a fourth set temperature that is higher than the first set temperature by a predetermined value and is lower than the second set temperature by a predetermined value is detected, Control is performed to open the second contact and stop heating by the heating means.

Example Next, regarding the operation control method of the refrigerator according to the present invention, a brine cooling type constant temperature and high humidity refrigerator is exemplified as an apparatus capable of suitably implementing the method, and will be described below with reference to the accompanying drawings.

(Regarding Schematic Structure of Refrigerator) As shown in FIGS. 1 and 2, a refrigerator capable of suitably implementing the operation control method for a refrigerator according to the present application has a stored product such as frozen food (hereinafter referred to as “food material”) inside. 2) is composed of a box 1 defining a horizontally long storage case 1a for cooling and storing the same and a cooling unit portion 10, and a top plate 11 is commonly arranged for both. A door 12 is rotatably supported at an opening of the storage case 1a so as to be openable and closable, and a mounting shelf (not shown) is horizontally provided inside the storage case 1a in a detachable manner. In the cooling unit section 10, the compressor C
M, fan motor FM ₃ (Fig. 4) A refrigeration unit 4 including a condenser 3 and the like, a brine cooling unit 13 having a brine tank 6, an electrical equipment box 17 (in-room temperature controller 15, thermometer 16 and the like). And) are provided.

In the cross section of the main part of the constant temperature and high humidity refrigerator shown in FIG. 2, a heat storage material 20 is filled between an outer box 18 and an inner box 19 which form the box body 1, and is defined in the inner box 19. A cooler 7 to which brine as a cooling medium is circulated and supplied is fixedly arranged on the upper left side inside 1a. Further, as shown in the figure, a cooling duct 21 having an open left side is provided below the cooler 7, and covers the cooler 7 in a non-contact state. This cooling duct
A required opening 22 is formed on the right side of 21 as shown in the figure, and two cool air circulation fan motors FM ₁ and FM arranged in this opening 22 are provided.
₂ (only one shown), the air in the refrigerator is sucked from the gap on the left side of the cooling duct 21, contacts the cooler 7 to perform heat exchange and is cooled, and then is blown out from the opening 22.
It circulates as shown by the solid arrow to cool the entire interior of the storage case 1a.

As shown in FIG. 4, a defrosting thermostat Th ₁ for detecting the end of defrosting and defrosting heaters H ₁ and H ₂ are arranged near the cooler 7. Further, a dew tray 27 is arranged below the cooler 7, and water droplets dropped from the cooler 7 at the time of defrosting are collected here and discharged to the outside of the refrigerator. Reference numeral 28 indicates a temperature-sensing portion of the in-compartment temperature detection thermos Th ₂ which is arranged in a proper place in the refrigerator. This internal thermo Th ₂
As shown in Figure 5, contact Th ₂ -a and contact Th ₂ -
b, the opening and closing characteristics of the both contacts are different between the first invention shown in FIG. 7 and the second invention shown in FIG. That is, in the first invention shown in the timing chart of FIG. 7,
Contact Th ₂ -a is open at the lower limit set temperature T ₁ of the storage room thermo Th ₂ (first set temperature), closing at the upper limit set temperature T ₂ (second set temperature). The contact Th ₂ -b, the lower limit set temperature T
The third that opens at ₁ and drops a prescribed temperature from the lower limit set temperature T ₁
Close at set temperature T ₃ . Therefore, the second set temperature T ₂ > the first
There is a relation of set temperature T ₁ > third set temperature T ₃ . The set temperatures T ₂ , T ₁ , T ₃ of the thermos Th ₂ in the refrigerator can be arbitrarily adjusted depending on the type of food stored in the refrigerator, and even if the lower limit temperature T ₁ is changed, the third set temperature T ₃ also changes with a given temperature interval.

In the second invention shown in the timing chart of Figure 8, contact Th ₂ -a, the lower limit of the internal thermo Th ₂ set temperatures T ₁
It opens at the (first set temperature) and closes at the upper limit set temperature T ₂ (second set temperature). The contact Th ₂ -b a predetermined temperature just higher than the lower limit set temperature T _1, and opens at a lower than the upper limit set temperature T ₂ fourth set temperature T _4. The approximate mean value of the third set temperature T ₃ and a fourth set temperature T ₄ of the is set first set temperature T ₁ of the so as. That is, the second set temperature T _2> 4th set temperature T _4> first set temperature T _1> third set temperature
The relation of T _3.

(Regarding Brine Cooling Unit) In FIG. 3, the brine is cooled by the refrigerating apparatus 4,
A brine cooling unit 13 that circulates and supplies the brine as a refrigerant to the cooler 7 is shown. This brine cooling unit 13 is a heat insulating material.
There is a brine tank 6 consisting of an outer box 29 and an inner box 30 which are filled with 31 interposed therebetween, and the upper opening thereof is removed by a lid body 35 which is also made up of an upper lid 32 and an inner lid 33 with a heat insulating material 34 interposed. Covered as much as possible. Further, each end edge portion of the upper lid 32 is bent at a right angle and is fitted into the outer box 29 of the tank 6 so that the upper edge portion of the tank 6 and the inner lid 33 come into close contact with each other. The end of the upper lid 32 is detachably fixed to the tank outer box 29 via a bolt.

One end of a suction pipe 36 is connected to a lower portion of a side wall of the inner tank box 30, the suction side of the brine circulation pump PM is connected to the other end of the suction pipe 36, and the pump discharge side is connected to the cooler 7. It is connected to the brine supply pipe 9. Also inner box
Discharge pipe that bends in a key shape and opens downward on the upper side wall of 30
37 is exposed, and the other end of the discharge pipe 37 is connected to the brine return pipe 14 from the cooler 7. In addition, these suction pipes 36,
The supply pipe 9, the discharge pipe 37, and the return pipe 14 are all insulated by a heat insulating hose 38. Further, a concave support plate 39 is fixed to the inner bottom portion of the tank 6, and an evaporator 40, which is drawn from the refrigerating device 4 and wound in a spiral shape, is arranged with the support plate 39 with its axis line horizontal, The brine 8 stored in 6 at a predetermined liquid level can be cooled to the required temperature.

The liquid level of the blank 8 stored in the brine tank is arranged so as to be located at a level lower than that of the cooler 7 arranged in the refrigerator, so that during the defrosting operation described later,
Brine 8 in the pipeline connecting the cooler 7 and the tank 6
However, they all return to the tank 6 without remaining.

(Refrigeration Circuit and Brine Circulation Circuit) FIG. 4 is a schematic system diagram of each pipeline system that constitutes a refrigeration circuit and a brine circulation circuit using a liquefied / vaporized refrigerant such as Freon. In the figure, the vaporized refrigerant compressed by the compressor CM becomes a liquefied refrigerant in the condenser 3, is dehumidified by the dryer 41, and is then decompressed by the capillary tube 42. Next, the evaporator 8 is evaporated and vaporized to cool the brine 8 in the brine tank 6. The vaporized refrigerant that has evaporated returns to the compressor CM again via the suction pipe. Reference numeral FM ₃ shows a fan motor for cooling a condenser 3.

Further, in the brine circulation circuit, the brine 8 in the tank 6 is
Is cooled to a required temperature by an evaporator 40 which constitutes a part of the refrigerating apparatus 4, and the cooled brine 8 is sucked out by a circulation pump PM through a suction pipe 36 and then connected to a discharge side. It is supplied from the brine supply pipe 9 to the cooler 7. The brine 8 exchanges heat with the air in the refrigerator in the cooler 7, and then is returned to the tank 6 via the brine return pipe 14 and the key-shaped discharge pipe 37.

FIG. 5 shows an electric control circuit of the constant temperature and humidity refrigerator shown in the embodiment. In the figure, a cam timer TM is connected between the power supply lines A and B, and the movable contact c provided on the line B side of the cam timer TM is connected to the fixed contact a side during the cooling operation by the timer drive motor M and is removed. Fixed contact b during frost operation
Switched to the side. Between the connection point K and line A is connected by contact Th ₂ -a of the internal thermo Th _2, between the connection point K and the fixed contact a, the compressor CM, the fan motor FM ₃ is in parallel It is connected. Note the thermo contact Th ₂ -a is
As shown in FIG. 7, the internal temperature T rises to a predetermined upper limit value T ₂
It is opened until it reaches, and it is closed when it reaches a predetermined upper limit value T ₂ . Further, the internal temperature T decreases and the predetermined lower limit value T ₁ (T ₁
It is closed until <T ₂ ) is reached, and is opened when a predetermined lower limit value T ₁ is reached.

The fan motors FM ₁ and FM ₂ are connected in parallel between the line A and the fixed contact a of the cam timer TM. Further, the line A and the connection point L are connected by a contact Th ₁ -b of the defrosting thermo Th ₁ , and the connection point L and the cam timer T are connected.
Between the M fixed contact b of the relay X ₁ and the heater H _1, H ₂ through the relay X ₂ normally closed contacts X ₂ -b are connected in parallel. Further fixed contact b of Kamutaima TM is connected to the line B through the normally open contact X ₂ -a of the relay X _2. Incidentally contact Th ₁ -b defrosting thermo Th _1, the temperature of the cooler 7 is configured to close (open at a predetermined value or more) at a predetermined value or less.

Between the line A and the connection point N, the normally-closed contact X ₁ -b that cooperates with the relay X ₁ is connected, and between the connection point N and the line B, the timer drive motor M and the pump motor PM are connected in parallel. It is connected to the. Line A, in between B, a contact Th ₂ -b and the relay X ₂ in the internal thermo Th ₂ are connected in series.

(Operation of Constant Temperature and High Humidity Refrigerator) Next, the actual operation of the constant temperature and high humidity refrigerator according to the embodiment will be described with reference to the timing chart shown in FIG. Prior to operation, first, the lid 35 of the brine tank 6
Remove and inject brine 8. The injection amount is a value obtained by summing the capacity of the brine 8 existing in the circulation conduit system and the amount of the proper liquid level stored in the tank 6.

Since the internal temperature T is higher, contact Th ₂ -a of the internal thermo-Th ₂ is closed. Therefore, when the power switch is turned on, the compressor CM and the fan motor FM ₃ of the refrigeration system are activated via the contact points a and c of the cam timer TM to start the operation of the refrigeration system. Also a normally closed contact that cooperates with relay X _1.
The motor M of the cam timer TM is energized via X _1- b, and counting of the time limit is started. Further, the normally closed contact X ₁ -b
The brine circulation pump PM is energized via the, and the brine 8 in the tank 6 is circulated and supplied from the discharge pipe 9 to the cooler 7.

The brine 8 that has been pumped by the pump PM and passed through the cooler 7 exchanges heat with the air in the refrigerator, and then returns to the inside of the tank 6 from the discharge pipe 37 via the return pipe 14. Then, the returned brine 8 is mixed with the cooled storage brine 8 in the tank 6, and is again circulated by the pump PM via the suction pipe 36. At this time, since the fan motors FM ₁ and FM ₂ in the refrigerator are rotating, the air that has been forcibly brought into contact with the cooler 7 for heat exchange is circulated in the refrigerator. Gradually decreases. When the circulation amount of the brine 8 is increased and the surface area of the cooler 7 is increased, the amount of heat exchange with the air in the cold storage increases, and the temperature difference between the cold storage temperature and the cooler 7 becomes extremely small. Therefore, the amount of frost on the cooler 7 is reduced, and high humidity is maintained.

The inside temperature is lowered, the temperature T reaches the lower limit set temperature T ₁ of the storage room thermo Th _2, thermo contact Th ₂ -a is opened, stopping the compressor CM and the fan motor FM _3. Since the pump PM and the fan motors FM ₁ and FM ₂ continue to operate, the brine 8 in the tank 6 continues to circulate in the pipeline system to continue cooling the inside of the refrigerator.

By the way, the internal temperature T rises over time under the influence of heat entering from the outside, heat generation of the fan motors FM ₁ and FM ₂ and heat radiation from foods, etc., whereby the brine that exchanges heat with the internal air is generated. The temperature of 8 also rises. When reaching the interior temperature T rises to the upper limit set temperature T ₂ of the storage room thermo Th _2, the compressor CM and the fan motor FM ₃ is activated by thermo contact Th ₂ -a is closed, The cooling operation is restarted. By repeating the above cycle, the internal temperature is maintained between the upper limit set temperature T ₂ and the lower limit set temperature T ₁ . During this period, frost adheres to the surface of the cooler 7 and gradually grows in layers.

When a predetermined time elapses while the above-described cooling operation is repeated, and the cam timer TM times out, the contact is b
Switched to -c side, compressor CM, fan motors FM ₁ , FM ₂ , FM ₃
All stop, and shift from the cooling operation to the defrosting operation of the refrigerator. Since that is the case the temperature of the cooler 7 sufficiently low, contact Th ₁ -b defrosting thermo Th ₁ is in a closed state in Figure 5. Therefore, energization of the heaters H ₁ and H ₂ and the relay X ₁ is started, the normally closed contact X ₁ -b cooperating with the relay X ₁ is opened by the excitation of the relay X ₁ , and the pump PM and the timer drive motor M are Stop its rotation.

Since the heating of the cooler 7 by the heaters H ₁ and H ₂ is sufficient only on the outer surface of the cooler 7, defrosting is performed in a short time, and the frost is melted to form water droplets, which are dropped on the dew tray 27 and discharged outside the storage. It When the pump PM is stopped, the cooler 7 is located above the brine level in the tank 6 as described above,
All the brine in the pipeline is returned to the tank 6, so that the brine 8 is not heated by the heaters H ₁ and H ₂ .

Since the temperature of the cooler 7 rises when defrosted, the defrosting thermo Th ₁ detects this and opens the contact Th _1- b, and the heaters H ₁ , H
Power to ₂ and relay X ₁ is cut off. When the relay X ₁ is deenergized, and the normally closed contact X ₁ -b again closed for cooperation with this, energization of the pump PM and the timer motor M is started. At this time, the contact point of the cam timer TM is on the bc side, so that neither the compressor CM nor the fan motors FM ₁ , FM ₂ and FM ₃ are operating. And by the rotation of the pump PM,
The brine 8 in the tank 6 is circulated and supplied to the cooler 7.
The brine 8 in the tank 6 is stored in cold due to its large heat capacity. Therefore, even if the brine 8 is not subjected to the positive forced cooling by the evaporator 40, the brine 8 is circulated through the cooler 7 to cool it and the vicinity of the cooler The heaters H ₁ and H ₂ are cooled to rapidly reduce the temperature inside the refrigerator.

That is, as shown in the timing chart of FIG.
When the internal temperature T reaches the point O (higher than the upper limit set temperature T ₂ ), the frost in the cooler 7 is completely melted, and the defrosting thermo Th ₁ detects this and the heaters H ₁ and H ₂ receive the frost. Power is cut off. Further, the relay X _{1 is} also deenergized, the normally closed contact X _1- b is closed, the pump PM is started, and the brine supply to the cooler 7 is restarted.
As a result, it is possible to suppress an increase in the internal temperature due to the residual heat of the cooler 7 and the heaters H ₁ and H ₂ , and to reduce the temperature change. After the power supply to the heaters H ₁ and H ₂ is cut off, the brine circulation in the cooler 7 keeps the internal temperature T substantially the same as the temperature at the point O, as shown by the solid line in the timing chart. .

Here, the difference between the temperature of the brine 8 and the internal temperature T is controlled to be about 1 to 3 ° C., and the temperature at the point O is maintained at 0 to 2 ° C.
Is immediately supplied to the cooler 7, the temperature of the cooler 7 is 0 ° C.
It does not occur and therefore the thawed water droplets do not refreeze. Further, since energization of the timer drive motor M is also started, the contact of the cam timer TM is switched to the ac side after a while, and the above-mentioned cooling operation is restarted. At this time, the internal cold storage temperature is only slightly higher than the upper limit set temperature T ₁ , and the time required to cool the stored food material to the optimum temperature can be shortened.

In the cooling operation described above, when the internal temperature is set to a temperature higher than 0 ° C, for example, 3 to 5 ° C, the temperature of the cooler 7 becomes higher than 0 ° C (because the brine temperature becomes higher than 0 ° C). Therefore, no frost is formed on the cooler 7. Therefore, even if the timer TM times out and enters the defrosting operation, the contact Th ₁ -b of the defrosting thermo Th ₁ continues to be in the open state,
Since the normally closed contact X ₁ -b remains closed, the timer motor M and the pump PM is always operated.

(If the ambient temperature of the refrigerator is lowered) in such a refrigerator thermostatic high humidity operation is continued, the use or the like of the use or the coldest season in cold climates, the ambient temperature of the refrigerator installation environment is the internal thermo Th ₂ Lower limit temperature T ₁
The case where it is further decreased will be described below. When the ambient temperature of the refrigerator falls below the lower limit set temperature T ₁ , strong external cold air gradually enters through the heat insulating material 31 of the brine tank 6, and the brine 8 cooled by the evaporator 40 is set to the set temperature. Start cooling to below. Further, cold air also enters from the heat insulating hose 38 surrounding the supply pipe 9 and the return pipe 14, and this also contributes to the temperature decrease of the brine 8.

Further, cold air enters the storage box 1a through the heat insulating material 20 of the inner box 19 and the heat insulating material (not shown) of the door 12 to cool the air circulating in the storage. This further cools the food in the refrigerator below the proper storage temperature and lowers the temperature of the cooler 7, and the brine circulating in the cooler 7 is also supercooled by this.

As shown in the timing chart of FIG. 7, the inside temperature T
When the temperature reaches a point e at the upper limit set temperature T _2, the operation of the compressor CM restarts, and when the internal temperature T drops to the point f at the lower limit set temperature T ₁ , the compressor CM stops the operation. . Further inside the refrigerator than the f point is cooled, the inside temperature T continues to drop and reaches up to a third predetermined temperature T ₃ in the internal thermo Th _2, the thermo Th ₂ contacts Th ₂ - b closes. Relay X ₂ is excited by the closing of said contact Th ₂ -b,
The normally open contact X ₂ -a cooperating with this is closed and the normally closed contact X ₂ -b is opened. At this time, since the contact Th ₁ -b defrosting thermo Th ₁ is closed, made energization to the heater H _1, H _2, is sufficiently cooled by cooler 7 was the heated to a temperature rise . Therefore, the brine circulating in the cooler 7 is heated, and the brine stored in the tank 6 is also mixed with this heated and returned brine to start increasing the temperature. Further, the rotation of the fan motors FM ₁ and FM ₂ causes the inside air to exchange heat with the cooler 7, and as a result, the inside temperature T starts to rise. Since the operation of the first invention differs from that of the second invention after the internal temperature T rises, description will be made separately for each case.

(Operation of First Invention) The operation of the first invention for performing the operation shown in FIG. 7 will be described. The internal temperature T that started to rise is the internal thermo Th ₂
When reaching the lower limit set temperature T ₁ (first set temperature) of the contact Th
Relay X _{2 2} -b is open is de-energized. The normally closed contact X ₂ -b with Thus the normally open contact X ₂ -a of the relay X ₂ is opened
Is closed, the energization of the heaters H ₁ and H ₂ is cut off, and the heating of the cooler 7 is stopped. Then, when the brine and the inside of the refrigerator are cooled again by the surrounding cool air, and the inside temperature T drops to the third set temperature T ₃ of the inside thermos Th ₂ , the heater is heated as described above.
H ₁ and H ₂ are energized to heat the inside of the refrigerator.

Invasion of cold air also occurs by opening and closing the door, and when a large amount of frozen food is stored in the refrigerator, if the ambient temperature of the refrigerator is higher than the lower limit set temperature T ₁ of the thermostat Th _{2 in} the refrigerator,
The negative heat capacity of the frozen food product cools the inside of the refrigerator, and the inside temperature T drops to the third set temperature T ₃ . However, as described above, the inside temperature T is controlled by the on / off control of the heaters H ₁ and H _2.
Is maintained between the first set temperature T ₁ and the third set temperature T ₃ .

After that, as the temperature of frozen foods increases, the heat capacity decreases,
Due to the rise in ambient temperature due to the start of indoor heating, etc., heat may enter the inside of the refrigerator. And although the point g Figure 7 until the point h electrical heating of the heater H _1, H ₂ is made, energization of the heater H _1, H ₂ becomes equal to or larger than h point is interrupted, the refrigerator by the outside air in the heat penetration The temperature T further rises. When the inside temperature T reaches the upper limit set temperature T ₂ of the inside thermos Th ₂ , the compressor C is charged as described above.
M starts operation and cools the brine to recool the inside.

(Operation of Second Invention) Next, the operation of the second invention for performing the operation shown in FIG. 8 will be described. When elevated interior temperature T started reaches the fourth set temperature T ₄ is higher by a predetermined value than the lower limit set temperature T ₁ of the storage room thermo Th _2, the relay X ₂ the contact Th ₂ -b is opened deenergizing To be done. Thus with the normally open contact X ₂ -a of the relay X ₂ is opened, the normally closed contact X ₂ -b is closed, the heater
The energization of H ₁ and H ₂ is cut off, and the heating of the cooler 7 is stopped. After that, the brine and the inside of the refrigerator are cooled again by the surrounding cool air, and when the inside temperature T drops to the third set temperature T ₃ of the inside thermos Th ₂ , the heaters H ₁ and H ₂ are energized to heat the inside of the refrigerator. Warm.

As in the case of the first aspect of the invention, cold air may enter the refrigerator,
The internal cooling or stores a large amount of frozen food in the refrigerator is made, even if the inside temperature T up to the third set temperature T ₃ is lowered, by on-off control of the heater H _1, H _2, refrigerator The internal temperature T is maintained between the fourth set temperature T ₄ and the third set temperature T ₃ . After that, the heat capacity of the frozen food decreases with the temperature rise, and the heat enters the inside of the refrigerator due to the increase of the ambient temperature due to the start of indoor heating. And from point g to point h in FIG.
The H ₁ and H ₂ are energized and heated, but when the temperature exceeds the point h, the energization of the heaters H ₁ and H ₂ is cut off, and the temperature T in the refrigerator further rises due to the invasion of heat from the outside air. When the inside temperature T is an upper limit set temperature T ₂ of the storage room thermo Th _2, to start the operation compressor CM as described above, re-cooled in the refrigerator to cool the brine.

In either case of the first invention and the second invention, the heaters H ₁ and H ₂ are originally provided for defrosting the cooler 7, but this further serves to prevent brine freeze. do. That is, when the internal temperature falls below the set temperature due to a decrease in ambient temperature or the like and the brine freeze temperature (generally −10 to −15 ° C.) or lower, the brine is stored in the tank 6,
Freezing occurs in the circulation system such as the pipelines 9 and 14 and the cooler 7, causing freezing failure and cooling failure. Therefore, the brine temperature is detected directly or indirectly, and the required brine freeze prevention means is operated by this detection signal to prevent brine freeze. This brine freeze protection means
The heaters H ₁ and H ₂ and the heater arranged in the tank 6 or the heating means such as the heater for heating the pipe lines 9 and 14 are constituted. In this embodiment, a heater is used as a brine freeze prevention means.
The case of using H ₁ and H ₂ has been described, but the present invention is not limited to this.

Effects of the Invention As described above, the operation control method for a refrigerator according to the first aspect of the present invention keeps the temperature inside the refrigerator constant by the on / off control of the refrigeration system at the temperature lower than or equal to the lower limit temperature inside the refrigerator, and sets the lower limit temperature inside the refrigerator. In the following, the temperature inside the refrigerator is controlled by the heating means. Therefore, the temperature inside the refrigerator is controlled within the range between the upper limit set temperature and the predetermined temperature below the lower limit set temperature, and even if the ambient temperature of the refrigerator is lowered, the stored food can be stored without freezing at low temperature. . Further, even if a large amount of frozen food is stored in the refrigerator, it is possible to prevent the freshness of the stored food material from being lowered due to the temperature drop. Further, the frozen food is heated by the heating means to be thawed, but the time required for the thaw can be shortened by setting the temperature inside the refrigerator which is optimum for the food.

In the refrigerator operation control method according to the second aspect of the present invention, during the cooling operation, when the in-compartment temperature detecting device detects a third set temperature that is lower than the first set temperature (in-compartment lower limit temperature) by a predetermined value, the heater. The heating by the heating means is started, and when the fourth set temperature which is higher than the first set temperature by a predetermined value and lower than the second set temperature by a predetermined value is detected, the heating by the heating means is stopped. It is a thing. That is, according to the method, for example, as a result of cold air entering the refrigerator or storing a large amount of frozen food in the refrigerator, the temperature inside the refrigerator is set to a third setting lower than the lower limit of the first set temperature. When the temperature drops to the temperature, the heating means is activated to raise the temperature, and when the internal temperature rises to a fourth set temperature between the first set temperature and the second set temperature, the heating means stops heating. By stopping, the internal temperature can be maintained between the fourth set temperature and the third set temperature. Therefore, it is excellent in thermostatic property, and it becomes possible to store the food material while keeping the freshness of the food material to a minimum by suppressing the change in the product temperature. Further, there is an advantage that the time for thawing the frozen food can be shortened by the heating means and the frozen food can be well preserved.

[Brief description of drawings]

1 is a front view showing a state in which a cover is removed from a cooling unit section of a constant temperature and high humidity refrigerator, and FIG. FIG. 3 is a vertical sectional view showing the internal schematic structure of the refrigerator, FIG. 3 is a vertical sectional view of a brine tank, and FIG.
FIG. 2 is a schematic explanatory view showing a pipeline connection state of a brine circulation circuit incorporated in the refrigerator shown in FIG. 2 and a refrigerant circulation circuit from a refrigeration system, and FIG. 5 is an electric control circuit for controlling the constant temperature and humidity refrigerator shown in FIG. FIGS. 6, 6, 7 and 8 are timing charts for explaining the operation of the electrical control circuit diagram shown in FIG. 1a ... Storage, 4 ... Refrigerator 6 ... Brine tank, 7 ... Cooler 8 ... Brine, 40 ... Evaporator H ... Heater

Claims (2)

[Claims] 1. An evaporator (4) forming a part of a refrigeration system (4).
The brine (8) in the brine tank (6) is cooled by (0), and the cooled brine (8) is stored in the storage (1a).
It is circulated to the cooler (7) arranged inside to cool the inside of the refrigerator,
The inside temperature detecting device (Th ₂ ) arranged at a proper place in the storage (1a) has a second set temperature (T ₂ ) related to the upper limit temperature inside the storage.
When the temperature is detected, the operation of the refrigerating system (4) is started, and when the first set temperature (T ₁ ) related to the lower limit temperature in the refrigerator is detected, the operation of the refrigerating system (4) is stopped and the refrigerator temperature detecting device ( Th ₂ )
When a predetermined temperature drop in the refrigerator is detected, the heating means (H ₁ , H ₂ ) provided in the cooler (7) is operated to circulate the brine (8) through the cooler (7). In the refrigerator configured to perform the heating or the defrosting of the cooler (7), the inside temperature detecting device (Th ₂ ) is opened at the first set temperature (T ₁ ) which is the inside lower limit temperature. , The first contact (Th ₂ −) that closes at the second set temperature (T ₂ ) which is the upper limit temperature in the refrigerator.
and a), while open at the first set temperature (T _1), the third set temperature by a predetermined temperature drop from the first set temperature (T ₁₎ (T ₃₎
In the second contact closes (Th ₂ -b) and have, during said refrigeration system (4) cooling operation is controlled as described above operation of the in-compartment temperature detector (Th ₂₎ but the third when detecting the set temperature (T ₃₎ which drops by a predetermined value than the first predetermined temperature (T _1), to close the second contact (Th ₂ -b) with said heating means (H _1, Start heating with H ₂ ),
Further, when the inside temperature is detected that the rose to the first set temperature (T _1), stopping the heating by the heating means (H _1, H ₂₎ by opening the second contact (Th ₂ -b) A method for controlling the operation of a refrigerator, which is characterized in that the control is performed. 2. An evaporator (4) forming a part of a refrigeration system (4).
The brine (8) in the brine tank (6) is cooled by (0), and the cooled brine (8) is stored in the storage (1a).
It is circulated to the cooler (7) arranged inside to cool the inside of the refrigerator,
The inside temperature detecting device (Th ₂ ) arranged at a proper place in the storage (1a) has a second set temperature (T ₂ ) related to the upper limit temperature inside the storage.
When the temperature is detected, the operation of the refrigerating system (4) is started, and when the first set temperature (T ₁ ) related to the lower limit temperature in the refrigerator is detected, the operation of the refrigerating system (4) is stopped and the refrigerator temperature detecting device ( Th ₂ )
When a predetermined temperature drop in the refrigerator is detected, the heating means (H ₁ , H ₂ ) provided in the cooler (7) is operated to circulate the brine (8) through the cooler (7). In the refrigerator configured to perform the heating or the defrosting of the cooler (7), the inside temperature detecting device (Th ₂ ) is opened at the first set temperature (T ₁ ) which is the inside lower limit temperature. , The first contact (Th ₂ −) that closes at the second set temperature (T ₂ ) which is the upper limit temperature in the refrigerator.
and a), with closing at the third set temperature by a predetermined temperature drop from the first predetermined temperature _{(T 1) (T 3)} , a predetermined temperature just higher than the first set temperature (T _1), and the upper limit set temperature and a second contact (Th ₂ -b) which opens at a lower than the second set temperature (T ₂₎ the fourth established temperature (T ₄₎ is, as the operation of the refrigeration system (4) described above During the controlled cooling operation, if the internal temperature detection device (Th ₂ ) detects the third set temperature (T ₃ ) that is lower than the first set temperature (T ₁ ) by a predetermined value, the second to start heating by contact (Th ₂ -b) is closing by said heating means (H _1, H _2),
When a fourth set temperature (T ₄ ) higher than the first set temperature (T ₁ ) by a predetermined value and lower than the second set temperature (T ₂ ) by a predetermined value is detected, the second contact (Th _2- b)
A method for controlling the operation of a refrigerator, characterized in that the refrigerator is opened to stop the heating by the heating means (H ₁ , H ₂ ).