JP3096555B2 - Cold air dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cool air dryer used for drying food or agricultural products.

[0002]

2. Description of the Related Art In this type of cool air dryer, for example, a refrigerant circuit as shown in FIG. 3 has been used. That is, the conventional cool air dryer 100 includes a drying cabinet 11 having an interior (not shown) for storing foods to be dried, an indoor unit 50, and a condenser 12, and discharges the compressor 13 provided on the indoor unit 50 side. The three-way valve 14 is connected to the side,
One outlet of the three-way valve 14 is connected to a condenser 15 provided in the condenser 12. Reference numeral 16 denotes a blower for forcibly cooling the condenser 15.

The condenser 15 is connected to a receiver 18 via a check valve 17 provided on the indoor unit 50 side, and the receiver 18 is connected to a cooler 20 (including 20A) via an expansion valve 19.
It is connected to the. The cooler 20 is connected to the suction side of the compressor 13 via the accumulator 48 to form an annular refrigeration cycle. The expansion valve 19 is connected to the cooler 2
The temperature at the outlet side of 0 is detected, and the opening is adjusted so that the degree of superheat is maintained at a predetermined value.

The other outlet of the three-way valve 14 is connected to a reheater 22
(Including 22A), and the reheater 22 is connected to the check valve 23.
Is connected to the liquid receiver 18 via the Each of the check valve 23 and the check valve 17 has the liquid receiver 18 side directed forward. Reference numeral 24 denotes a blower for forcibly circulating the air exchanged with the cooler 20 and the reheater 22 into the refrigerator.

[0005] A defrost circuit 25 is connected to the discharge side of the compressor 13 before the three-way valve 14. The defrost circuit 25 is connected between the expansion valve 19 and the cooler 20 via an on-off valve 26 and a capillary tube 35. It is connected to the.
The on-off valve 26 detects the temperature on the outlet side of the cooler 20 and opens and closes the defrost circuit 25 (indicated by * 2 in the figure). Also,
The three-way valve 14 is controlled by a control circuit 27 (indicated by * 1 in the figure),
Is connected to a drying thermostat 28 and a cooling thermostat 29 for detecting the temperature in the refrigerator.

Further, a capacity control circuit 44 of a cylinder bypass type constituting a capacity control device is attached to the compressor 13 and is constituted by a thin tube having on-off valves 45 and 46 and a check valve 47 connected in series. , A discharge side and a suction side of the compressor 13 before the three-way valve 14 are communicated.

Reference numeral 36 denotes an on-off valve, and 30 denotes a liquid solenoid valve, which is always open. 37, 38 and 39 are a dryer, an indicator and a strainer, respectively.
An oil control circuit 40 returns lubricating oil to the compressor 13. A liquid injection circuit 43 for cooling the compressor 13 having an on-off valve 41 and a thermo valve 42 is connected to the compressor 13 from the outlet of the liquid receiver 18.

On the other hand, a conventional cooler (hereinafter, referred to as 20A) and a reheater (hereinafter, referred to as 22A) are so-called plate fins each having a plurality of radiating fins penetrated through a meandering refrigerant pipe. It consists of a type of heat exchanger. And the indoor unit 5 of the conventional cool air dryer 100
In the cabinet 51 of No. 0, the cooler 20A is disposed obliquely corresponding to the inside of the air suction port 6 at the center, and the reheater 22A is provided horizontally above the cooler 20A.

The blower 24 is provided in the cabinet 51 so as to correspond to the upper air outlet 7.
When the blower 24 is operated, the air in the drying chamber is sucked through the air suction port 6 as shown by an arrow in FIG. 5, passes through the cooler 20A and the reheater 22A sequentially, and then passes through the blower 24 to the air discharge port 7. It is configured to be blown out into the drying cabinet.

The operation of the above-described cool air dryer 100 will be described. The cold air dryer 100 has an internal temperature of, for example, + 15 ° C. to + 15 ° C.
The temperature is used in the range of 30 ° C., and the control circuit 27 is set to, for example, the above-mentioned internal temperature of + 15 ° C. Then, the control circuit 27 operates the compressor 13 and sets the flow path of the three-way valve 14 to the one outlet direction until the internal temperature decreases to the set temperature. Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 13 is
After entering the condenser 15 via the three-way valve 14 and radiating and condensing the heat there, it enters the receiver 18 via the check valve 17, and includes the on-off valve 36, the dryer 37, the indicator 38 and the on-off valve 30.
Through the expansion valve 19.

The expansion valve 19 is connected to the cooler 20 (20) as described above.
The degree of opening is adjusted based on the temperature at the outlet side of A), and the condensed and liquefied refrigerant is throttled and supplied to the cooler 20 (20A). The refrigerant flowing into the cooler 20 (20A) evaporates, absorbs heat from the surroundings to exhibit a cooling function, and is then sucked into the compressor 13 via the accumulator 48.

When the inside temperature of the refrigerator decreases to the set temperature (+ 15 ° C.) by the cooling operation, the drying thermostat 2
The control circuit 27 switches the flow path of the three-way valve 14 in the direction of the other outlet by detecting the temperature in the refrigerator by 8. As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 13 enters the reheater 22 (22A) via the three-way valve 14, where it radiates heat and exhibits a heating effect. On the other hand, the refrigerant is condensed there, enters the receiver 18 via the check valve 23, and thereafter flows as described above.

By the reheating operation, the temperature in the refrigerator becomes, for example, +
When the temperature rises to 18 ° C. (differential 3 ° C.), the control circuit 27 switches to the cooling operation again by detecting the rise in the internal temperature by the drying thermostat 28, and thereafter performs the cooling operation and the reheating operation as described above. repeat.

The air in the drying chamber sucked from the air inlet 6 by the operation of the blower 24 is cooled by the cooler 20 (20A).
The water contained in the air is cooled by the cooler 2
After being condensed to 0 (20A), it is heated by the reheater 22 (22A) and is blown out and circulated from the air discharge port 7 into the refrigerator. It is cooled and dried.

When the refrigerator is to be kept cool, the three-way valve 14 is forcibly switched to the condenser 15 and the compressor 13 is controlled by the cooling thermostat 29 so that the inside of the refrigerator is kept at a predetermined cooling temperature. To maintain.

[0016]

Here, the reheater 2
2 (22A) and the heat exchange capacity of the cooler 20 (20A) are the same, the amount of heat of heating in the reheater 22 (22A) and the amount of heat of cooling in the cooler 20 (20A) are not normally equal. As shown in the Mollier diagram, for example, the heating heat becomes about 1.2 times the cooling heat. Therefore, the cooling / reheating operation can be switched relatively frequently as it is, and there is a problem of aging of the equipment.

For this reason, conventionally, the number of rows and the number of stages of the refrigerant pipes of the cooler 20A and the reheater 22A are made different, and the overall dimensions and the like are also made different so as to equalize the amount of cooling heat and the amount of heating heat. But the cooler 20A and the reheater 2
Since 2A has a completely different structure, the workability and assemblability of each part is poor, and the resistance of the air passing through the cooler 20A and the reheater 22A is remarkably different, so that the wind speed becomes uneven and the heat exchange becomes difficult. There was a problem that the efficiency was also reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional technical problems, and aims at commonization of components constituting a cooler and a reheater and improvement of assemblability.
An object of the present invention is to provide a cool air dryer capable of improving heat exchange efficiency.

[0019]

SUMMARY OF THE INVENTION A cold air dryer 1 according to the present invention.
Is provided with a cooler 20 and a reheater 22, and condenses the high-temperature refrigerant discharged from the compressor 13 in the condenser 15, depressurizes and flows into the cooler 20, thereby exhibiting a cooling effect. The high-temperature refrigerant flows into the reheater 22 to exert a heating action. The cooler 20 and the reheater 22 penetrate the plurality of radiation fins Fa, Fb through the meandering refrigerant pipes Ca, Cb, respectively. And the same number of rows and stages of both refrigerant pipes Ca, Cb, and
The radiation fins Fa and Fb are arranged at different pitches.

[0020]

According to the cool air dryer 1 of the present invention, the cooling fins 20 and the reheaters 22 have the same number of refrigerant pipes Ca and Cb in the same number of stages and rows, and the radiation fins penetrate them. By making the pitches of Fa and Fb different, the amount of cooling heat in the cooler 20 and the amount of heating heat in the reheater 22 can be equalized. Therefore, the components constituting the cooler 20 and the reheater 22 can be shared, and the cost can be reduced and the assembling workability can be improved. In addition, since the overall dimensions of the cooler 20 and the reheater 22 can be made the same, it is possible to suppress the wind speed of the air passing therethrough from becoming uneven, and to improve the heat exchange efficiency.

[0021]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical sectional side view of a cabinet 51 of an indoor unit 50 of the cool air dryer 1 of the present invention, and FIG. 2 is a plan view of a cooler 20 and a reheater 22 of the cool air dryer 1 of the present invention. still,
The refrigerant circuit of the cool air dryer 1 is the same as that of FIG.
Since the function of the reheater 22 is the same as that of the reheater 22, the description of the configuration and operation of the refrigerant circuit is omitted.

The indoor unit 50 of the cool air dryer 1 of the present invention
A cooler 20 and a reheater 22 are provided in the cabinet 51 corresponding to the air inlet 6 at the center. The cooler 20 is a heat exchanger that penetrates a plurality of radiating fins Fa made of an aluminum thin plate or the like through a meandering refrigerant pipe Ca, and the reheater 22 also has a plurality of similar radiating fins Fb.
And a substantially rectangular heat exchanger penetrating the meandering refrigerant pipe Cb. The outer dimensions of the cooler 20 and the reheater 22 are substantially the same, and they are erected at predetermined intervals inside the air suction port 6, respectively, and the coolers 20 are sequentially arranged as the air suction port 6 side. Has been established.

A machine room 8 is provided below the cabinet 51, and the compressor 13, the liquid receiver 18, etc., which constitute a refrigerant circuit, are installed therein. In the cabinet 51, the blower 24 is provided corresponding to the upper air discharge port 7, and when the blower 24 is operated, the air in the drying chamber is supplied from the air suction port 6 as shown by an arrow in FIG. Sucked, cooler 2
After being sequentially cooled and dehumidified and heated by passing through the inside of the reheater 22 and the inside of the reheater 22, the air is blown out from the air discharge port 7 into the drying chamber through the blower 24.

Here, assuming that the relationship between the cooling heat amount and the heating heat amount of the refrigerant circuit is 1: 1.2 as described above, the heat exchange capacity of the cooler 20 is 1, and the heat exchange capacity of the reheater 22 is 1. By setting the ratio to 0.8, the amount of cooling heat in the cooler 20 and the amount of heating heat in the reheater 22 are equalized, and the inconvenience of frequently repeating the cooling / reheating operation as described above is eliminated.

Therefore, in the present invention, the cooler 20 and the reheater 2
2, the number of rows and the number of stages of the meandering refrigerant pipes Ca and Cb are the same, and the radiating fins Fa and Fb also have the same radiating area. It is arranged so that the heater 22 side becomes 0.8.

As a result, the heat exchange capacity of the cooler 20 and the reheater 22 becomes 1: 0.8, so that the amount of cooling heat and the amount of heating heat in them are equalized. In addition, since the components of the refrigerant pipes Ca and Cb and the radiation fins Fa and Fb can be shared, the cost can be reduced and the assembling workability is improved. Further, since the outer dimensions of the cooler 20 and the reheater 22 can be shared, a change in the wind speed of the air passing therethrough can be suppressed, and the heat exchange efficiency can be improved.

In particular, since the outer dimensions are common, it is possible to arrange the cooler 220 and the reheater 22 side by side with the air inlet 6 standing as in the embodiment. Become. Therefore, the dew adhering to the cooler 20 smoothly flows downward and is discharged, so that the ventilation resistance can be reduced and the air flowing through the cooler 20 can be equalized, so that the heat in the cooler 20 can be reduced. Exchange efficiency is also improved. Further, since it is not necessary to make the air passage passing therethrough bent as in the related art, it is possible to further reduce the ventilation resistance and make the wind speed uniform.

[0028]

As described above in detail, according to the present invention, the pitch of the radiating fins penetrating through the cooling pipe and the reheater is set in the same condition with the same number of stages and rows of refrigerant pipes. By making them different, the amount of cooling heat in the cooler and the amount of heating heat in the reheater can be equalized.

Therefore, the components constituting the cooler and the reheater can be shared, and the cost can be reduced and the assembling workability can be improved. Further, since the overall dimensions of the cooler and the reheater can be made the same, it is possible to suppress the air velocity of the air passing therethrough from becoming uneven, and to improve the heat exchange efficiency.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a cabinet of an indoor unit of a cool air dryer of the present invention.

FIG. 2 is a plan view of a cooler and a reheater of the cool air dryer of the present invention.

FIG. 3 is a refrigerant circuit diagram of the cool air dryer.

FIG. 4 is a diagram showing the relationship between the amount of heating heat in the reheater of the cool air dryer and the amount of cooling heat in the cooler.

FIG. 5 is a vertical sectional side view of a cabinet part of an indoor unit of a conventional cool air dryer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cold air dryer 6 suction port 7 discharge port 20 cooler 22 reheater 24 blower 50 indoor unit 51 cabinet Ca refrigerant pipe Cb refrigerant pipe Fa radiation fin Fb radiation fin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-155079 (JP, A) JP-A-4-116384 (JP, A) JP-A-55-146359 (JP, A) JP-A-58-158 108383 (JP, A) JP-A-5-308943 (JP, A) JP-A-62-120162 (JP, U) JP-A-4-25975 (JP, U) JP-A-3-56878 (JP, Y2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F26B 21 / 02,21 / 04 F28F 1/32 A23L 3/40

Claims (1)

(57) [Claims] 1. A cooling device comprising a cooler and a reheater, wherein a high-temperature refrigerant discharged from a compressor is condensed in a condenser, depressurized and flows into the cooler, thereby exhibiting a cooling function. In a cool air dryer that causes a high-temperature refrigerant to flow into the reheater and exerts a heating action, the cooler and the reheater are:
Each of the plurality of radiation fins was constituted by a heat exchanger penetrating a meandering refrigerant pipe, the number of rows and the number of stages of both refrigerant pipes were the same, and the radiation fins were arranged at different pitches. A cool air dryer characterized by the following.