JP4809944B2 - Indirect cooling storage - Google Patents

Description

  The present invention relates to an indirectly cooled storage.

A constant temperature and high humidity store is known as an example of this type of indirectly cooled storage, and a general structure is a heat insulating box having a front opening as shown in FIG. And an inner box 3 made of a heat conducting member having a front opening accommodated in the outer box 1 so as to form a duct 4 between the outer box 1 and the duct. The inside box 3 is indirectly cooled by circulating the cold air generated by the refrigeration apparatus 4 (see, for example, Patent Document 1).
In short, the inside of the warehouse is indirectly cooled by cooling the inside of the duct 4, and the inside of the warehouse has heat entering from outside (outside of the warehouse), and is provided on the front frame. Since there is heat entering from the dew-proof heater 5 or the like, generally, the relationship is [ambient temperature T2> inside temperature T1> duct temperature T0].
Therefore, in this type of constant-temperature high-humidity storage, when the internal temperature T1 is maintained at the preset temperature T1x, the duct temperature T0 is set to [set temperature T1x-bias value] in view of the above temperature relationship. By controlling the operation of the refrigeration apparatus so as to be equal to the internal temperature, the internal temperature T1 is maintained at the set temperature T1x. Conventionally, the “bias value” is set as a fixed value.
JP-A-10-246564

  However, the “bias value” may fluctuate under the influence of the set temperature T1x in the cabinet, the ambient temperature T2, the energization rate of the dew proof heater 5, and the like. For example, when the ambient temperature T2 is high in summer or the like, and the bias value is a fixed value, the inside temperature T1 does not decrease to the set temperature T1x at all even though the cooling control operation is performed. Things happen. In this case, for example, it is necessary to perform so-called feedback control in which the difference between the actual internal temperature T1 and the set temperature T1x is observed and the “bias value” itself is corrected based on the difference. If the correction is appropriate, the internal temperature T1 may be maintained in the vicinity of the set temperature T1x after that, but there is a problem that it takes an appropriate time to do so.

In addition, this type of indirectly cooled storage has a function of displaying the temperature in the inner box 3, that is, the temperature in the chamber, on the temperature display section, and it is useful for the user to display the temperature in the center of the chamber at that time. In general, however, the internal temperature detected by the internal temperature sensor is higher than the internal center temperature due to the location of the temperature sensor. For this reason, the temperature obtained by subtracting the “display correction value” from the temperature detected by the internal temperature sensor is regarded as the internal center temperature, and the same temperature is displayed. Conventionally, the “display correction value” is set as a fixed value.
However, this “correction value for display” may also fluctuate under the influence of the set temperature T1x in the cabinet, the ambient temperature T2, or the energization rate of the dew-proof heater 5 provided on the front frame. When the “correction value” is a fixed value, there is a problem that the center temperature in the refrigerator cannot always be accurately displayed.

  The present invention has been completed based on the above circumstances, and its purpose is to enable accurate and quick control to maintain the internal temperature at a set temperature in an indirectly cooled storage. It is in. Another object is to make it possible to accurately estimate and display the center temperature in the cabinet.

The invention according to claim 1 is a front surface which is composed of a heat insulating box having a front opening and has a heat insulating door attached to the front opening and a duct formed between the outer box and the outer box. An inner box made of a heat conducting member having an opening, and an indirect cooling storage in which the inside of the inner box is indirectly cooled by circulating cold air generated by a refrigeration apparatus in the duct. A duct temperature sensor for detecting the temperature, a set temperature input means for inputting the set temperature in the inner box, a duct temperature detected by the duct temperature sensor, and a store input by the set temperature input means for the store An operation control means for comparing the target value obtained by subtracting the bias value from the inner set temperature and controlling the operation of the refrigeration apparatus based on the comparison result to maintain the inner box at the inner set temperature. Before and Having said bias value, inside temperature, and at where the structure is bias value calculation means for calculating, based on the duty factor of the anti-condensation heater arranged to ambient temperature and front frame of the outer box is provided.

According to a second aspect of the present invention, there is provided a front surface comprising a heat insulation box having a front opening and having a heat insulation door mounted on the front opening, and a front surface accommodated in the outer box so as to form a duct. In an indirect cooling storage in which the inner box is indirectly cooled by circulating cold air generated by a refrigeration device through the duct, and an inner box made of a heat conducting member having an opening. The internal temperature sensor that detects the temperature and the temperature obtained by subtracting the display correction value from the internal temperature detected by the internal temperature sensor, and the calculated value is displayed in the temperature display section as the central temperature of the internal temperature. And a correction for calculating the display correction value based on the internal temperature , the ambient temperature, and the energization rate of the dew-proof heater disposed on the front frame of the outer box. The feature is that it has a configuration with value calculation means. To.

<Invention of Claim 1>
The refrigeration apparatus is controlled and operated so that the temperature in the duct becomes a temperature obtained by subtracting the bias value from the set temperature in the refrigerator. Here, as the bias value, the inside temperature of the factors influencing the setting of the bias value, and based on the duty factor of the anti-condensation heater arranged to ambient temperature and the front frame, advance appropriate value is calculated The calculated value is applied to the bias value during the control operation.
Therefore, it is possible to quickly and accurately perform control for accurately maintaining the internal temperature at the set temperature without causing a time lag. When calculating the bias value, it takes in the ambient temperature, which is likely to have a large effect on the setting of the bias value, and the current rate of the dew-proof heater placed on the front frame. Can be obtained.

<Invention of Claim 2>
The temperature obtained by subtracting the display correction value from the internal temperature detected by the internal temperature sensor is regarded as the internal center temperature and displayed on the temperature display section. The display correction value where the correction value of the inside temperature to be factors influencing the setting, and on the basis of the duty factor of the anti-condensation heater arranged to ambient temperature and the front frame, advance money value It is calculated and the calculated value is applied to the display correction value when calculating the above-mentioned center temperature in the warehouse. Thereby, the center temperature in a store | warehouse | chamber can be correctly displayed on a display part. The calculation of the display correction value takes in the ambient temperature, which is likely to have a large effect on the setting of the display correction value, and the current ratio of the dew-proof heater placed on the front frame, making it more reliable. A high appropriate value can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, a constant temperature and high humidity store is illustrated.
The overall structure will be described first. In FIG. 1, reference numeral 10 denotes an outer box composed of a heat insulating box having a front opening, and is supported by legs 11 arranged at four corners of the bottom surface. Inside the outer box 10, an inner box 12 made of a heat conducting member having a front opening is also stored with a gap, and a duct 15 for circulating cold air is formed at the same interval. Is the storage chamber 13 (hereinafter referred to as the interior as appropriate). At the front opening of the outer box 10, a heat insulating partition frame 16 is fitted sideways at the center height position to form two upper and lower doors 17, and a heat insulating door 18 can be swingably opened and closed. Has been.

A machine room 20 surrounded by a panel is provided on the upper surface of the outer box 10, and a window hole 21 is opened on the bottom surface of the machine room 20, that is, on the back side of the ceiling wall of the outer box 10. A heat insulating unit base 22 is placed so as to close 21. On the upper surface of the unit base 22, a refrigeration apparatus 23 including a compressor 24, an air-cooled condenser 25, and the like is placed.
On the other hand, on the back side of the ceiling portion in the outer box 10, a cooler chamber 28 is formed by stretching an air duct 27 that also serves as a drain pan, and a cooler 30 attached to the lower surface of the unit base 22 is accommodated. Yes. The cooler 30 and the refrigeration apparatus 23 are circulated and connected through a refrigerant pipe to form a known refrigeration cycle. An internal fan 32 is provided in front of the cooler 30 in the cooler chamber 28 and faces the upper position of the duct 15 described above.
Note that a dew proof heater 35 is provided on the back side of the front frame 17 </ b> A serving as the rim of the entrance / exit 17.

In the cooling operation, when the refrigeration apparatus 23 and the internal fan 32 are driven, air is drawn into the cooler chamber 28 from the upper side of the duct 15 and cool air is generated while passing through the cooler 30. Cold air is blown out from the outlet 33 on the back side and circulates and circulates through the duct 15. The wall surface of the inner box 12 is cooled by this cold air, and the storage chamber 13 (inside the box) is indirectly cooled from the wall surface.
During this time, as will be described in detail later, the temperature in the duct 15 is compared with the temperature (target value) obtained by subtracting the bias value from the internal set temperature, and the refrigeration is performed depending on whether the duct temperature is higher or lower than the target value. By controlling the operation and stop of the device 23 (internal fan 32), it is intended that the storage chamber 13 (inside the internal chamber) is maintained at substantially the set temperature.

In this embodiment, the “bias value” that is the basis of the target value necessary for the control operation of the refrigeration apparatus 23 is not set to a fixed value as in the prior art, but depends on the operating conditions, conditions, and the like. This function will be described below with reference to FIGS. 2 to 4. FIG.
Although it can be said that the “bias value” is obtained by subtracting the internal set temperature from the duct temperature, it is considered that the value varies depending on the internal temperature, the ambient temperature, and the energization rate of the dew-proof heater 35.

Therefore, the entrance and exit of heat into the cabinet is examined using the model shown in FIG. First, assume that the duct temperature is T0 (° C), the internal temperature is T1 (° C), the ambient temperature is T2 (° C), and these are balanced. Here, if T0 <T2, T1 always takes a value between T0 and T2, and T0 <T1 <T2.
Here, the amount of heat Hin1 per hour moving from the “ambient” to the interior is
Hin1 = K12 ・ A12 ・ (T2 -T1) (kcal) (1)
Further, intrusion heat from the dewproof heater 35 enters into the cabinet. Although the rated power consumption P (kcal / h) of the dew proof heater 35 is fixed, no voltage is always applied to the dew proof heater 35, and the current supply duty (%) changes. Moreover, not all of the heat generated in the dew-proof heater 35 flows into the cabinet, and if only a (%) of that heat flows in, the per-hour movement from the “dew-proof heater 35” into the cabinet will occur. The amount of heat Hin2 is
Hin2 = P ・ (duty / 100) ・ (a / 100) (kcal) (2)
On the other hand, the amount of heat Hout per hour moving from the interior to the duct 15 is
Hout = K01.A01. (T1-T0) (kcal) (3)

As described above, since the duct temperature T0, the internal temperature T1, and the ambient temperature T2 are balanced, the amount of heat flowing into the internal space is equal to the amount of heat flowing out.
Therefore, the following expression (4) is established from the above expressions (1), (2), and (3).
K12 · A12 · (T2-T1) + P · (duty / 100) · (a / 100) = K01 · A01 · (T1-T0) (4)
If K12, A12, K01, A01, a, and P are constants, equation (4) can be transformed into the following equation (5).
T0 = T1−α · (T2−T1) −β · duty (5)
Further, when there are N dew-proof heaters 35, the following equation (6) is obtained.

In the following, the mathematical formula shown in the following equation 2 is abbreviated as [Σβ · duty].

In the above equation (6), α and β are constants. The ambient temperature T2 of the constant temperature and high humidity chamber outside the chamber can be read from the ambient temperature sensor 42. Moreover, since the control part 40 (refer FIG. 3) itself controls the energization rate duty of the dew-proof heater 35, since the internal temperature T1 can be substituted by the internal set temperature T1x, these are also understood.
α and β are thermal property values of the storage body. If the values are obtained by tests, the duct temperature T0 can be obtained even if T1, T2 and duty change.

Further, as described above, the bias value B is the value obtained by subtracting the internal set temperature T1x from the duct temperature T0. Here, the internal set temperature T1x and the internal temperature T1 may be regarded as the same.
From the above equation (6), the following equation (7) is obtained.
Bias value B = T1−T0 = α · (T2−T1) + Σβ · duty (7)
From the above equation (7), it can be seen that the bias value B varies depending on the ambient temperature T2, the internal set temperature T1x (T1), and the conductivity duty of the dew proof heater 35. Conversely, these can be detected or read. Therefore, the bias value B can be calculated by the above equation (7).

  In the present embodiment, the cooling control operation is executed based on the program stored in the control unit 40 shown in FIG. 3, and as described above, on the input side of the control unit 40. Are connected with a duct temperature sensor 41 for detecting the duct temperature T0, an ambient temperature sensor 42 for detecting the ambient temperature T2, and an internal set temperature input section 43 for inputting the internal set temperature T1x, and on the output side. The refrigeration apparatus 23 (compressor 24), the internal fan 32, and the dew proof heater 35 are connected. Further, the control unit 40 compares the bias value calculation unit 45 that calculates the bias value B with the above equation (7), the duct temperature T0, and the target value TM obtained by subtracting the bias value B from the internal set temperature T1x. A comparison unit 46 is provided for controlling the operation and stop of the refrigeration apparatus 23 (internal fan 32) depending on whether the duct temperature T0 is higher or lower than the target value TM.

In other words, the cooling control operation according to the present embodiment is performed as follows. First, in the bias value calculation unit 45 of the control unit 40, the bias value B is calculated by substituting the ambient temperature T2, the internal set temperature T1x (T1), and the conductivity duty of the dew proof heater 35 into the equation (7). Is done. Then, the comparison unit 46 compares the duct temperature T0 with the target value TM obtained by subtracting the bias value B from the internal set temperature T1x, and the duct temperature T0 is the target value TM (in reality, an upper limit higher than the target value TM by a predetermined value). If the duct temperature T0 is lower than the target value TM (actually a lower limit value lower than the target value TM), the refrigeration apparatus 23 and the internal fan 32 are operated. The internal fan 32 is stopped, and by repeating this operation, as shown in FIG. 4, the duct temperature T0 is substantially maintained at the target value TM, and as a result, the internal temperature T1 is higher than the target value TM by the bias value B. The internal set temperature T1x is maintained.
In the above, when any one of the ambient temperature T2, the internal set temperature T1x, and the conductivity duty of the dewproof heater 35 is changed, the bias value B is newly calculated and changed, and the target based on the new bias value B is changed. The control operation is performed while comparing the value TM with the duct temperature T0.

  As described above, in this embodiment, the control temperature is maintained so that the duct temperature T0 is maintained at the target value TM obtained by subtracting the bias value B from the internal set temperature T1x, so that the internal temperature T1 is Although the set temperature T1x is maintained, the “bias value B” that is the basis of the target value TM required for the control operation is not set to a fixed value as in the prior art, but the operating conditions and conditions, etc. It is variable according to. Specifically, the internal temperature T1 (internal storage temperature T1x), the ambient temperature T2, and the energization rate duty of the dew-proof heater 35 disposed on the front frame 17A are likely to affect the setting of the bias value B. An appropriate value is calculated in advance based on the above, and the calculated value is applied to the bias value B during the control operation. As a result, the control for accurately maintaining the internal temperature T1 at the set temperature T1x can be performed quickly and accurately without causing a time lag.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. In this Embodiment 2, when displaying the actual internal temperature T1, especially the internal center temperature Tc, with respect to the temperature display part 51 equipped in the constant temperature and high humidity store, it intends to display correctly. Yes.
When the internal temperature T1 is displayed on the temperature display unit 51, it can be said that it is useful for the user to display the internal temperature Tc. However, in general, the internal temperature T1 detected by the internal temperature sensor 52 is the same temperature sensor. From the relationship of the arrangement position of 52, it is higher than the inside center temperature Tc. For this reason, the temperature obtained by subtracting the display correction value TH from the temperature detected by the internal temperature sensor 52 is regarded as the internal temperature Tc and displayed. Conventionally, the correction value TH has been set as a fixed value (for example, 1 ° C.).

However, the correction value TH may fluctuate due to the influence of the internal temperature T1, the ambient temperature T2, or the energization rate of the dew-proof heater 35 provided on the front frame 17A. Therefore, the correction value TH is fixed. If the value is a value, there is a situation in which the inside center temperature Tc cannot always be accurately displayed.
Therefore, as a result of various tests and the like, an appropriate display correction value TH is obtained by calculating the difference between the internal temperature and the duct temperature used for obtaining the bias value in the first embodiment [internal temperature T1−duct temperature T0. The second embodiment has been completed based on this finding. This will be described in detail below.

As described in the first embodiment, the following formula (11) is established as a formula for calculating the bias value.
T0 = T1−α · (T2−T1) −Σβ · duty (11)
The above equation (11) is the same as the equation (6) in the first embodiment, and α and β are constants and are thermal physical properties of the storage body.
Although there is a difference between the internal temperature T1 detected by the internal temperature sensor 52 and the internal temperature Tc, the internal temperature Tc is usually lower. When the difference between the two temperatures T1 and Tc is defined as a display correction value TH,
Display correction value TH = T1-Tc (12)
Therefore, the temperature display unit 51 may display [Tc = T1−correction value TH for display]. Here, it has been experimentally found that the display correction value TH is not constant and can be approximated by a value proportional to the difference between the internal temperature T1 and the duct temperature T0. That is,
Display correction value TH = γ · (T1-T0) (13)

When the above equation (11) is transformed,
T1-T0 = α · (T2-T1) + Σβ · duty (11a)
This formula (11a) is the same as the formula (7) in the first embodiment.
Substituting equation (12) into equation (11a),
T1−T0 = α · {T2− (display correction value TH + Tc)} + Σβ · duty (11b)
Substituting equation (13) into equation (11b),
T1−T0 = α · [T2− {γ · (T1−T0) + Tc}] + Σβ · duty (11c)
When formula (11c) is transformed,
T1−T0 = {α · (T2−Tc) + Σβ · duty} / (1 + α · γ) (11d)
Here, when [T1−T0] is defined as “bias value b” as in the first embodiment, the following equation (11d) and equation (13) are obtained.
Bias value b = {α · (T 2 −Tc) + Σβ · duty} / (1 + α · γ) (14)
Display correction value TH = γ · bias value b (13a)

If the internal temperature T1 is controlled to take the following value during the cooling operation, the internal temperature Tc becomes the internal set temperature T1x set by the user.
Target value of chamber temperature T1 = chamber set temperature T1x + display correction value TH (15)
Substituting equation (13a) into equation (15) above,
Target value of chamber temperature T1 = Chamber set temperature T1x + γ · Bias value b (16)
As described above, the refrigeration apparatus 23 (compressor 24) is controlled in relation to the duct temperature T0, but it is sufficient that the duct temperature T0 is controlled to take the following value.
Duct temperature T0 target value Tm = compartment set temperature T1x + display correction value TH-bias value b (17)
Substituting equation (13a) into equation (17),
Duct temperature T0 target value Tm = inside chamber set temperature T1x− (1-γ) · bias value b (18)
The chamber center temperature displayed on the temperature display 51 is
Display temperature = T1-Display correction value TH (19)
Substituting equation (13a) into equation (19),
Display temperature = T1-γ · Bias value b (20)

In summary, as described above, the in-chamber center temperature Tc can be replaced with the in-chamber set temperature T1x set by the user.
Bias value b = {α · (T2−T1x) + Σβ · duty} / (1 + α · γ) (14a)
Display correction value TH = γ · bias value b (13a)
Target value of chamber temperature T1 = Chamber set temperature T1x + γ · Bias value b (16)
Target value of duct temperature T0 = in-chamber set temperature T1x− (1-γ) · bias value b (18)
Display temperature = T1-γ · Bias value b (20)
Here, three constants α, β, and γ can be set, and the bias value b varies.

In the second embodiment, the cooling control operation is executed based on the program stored in the control unit 50 shown in FIG. 6. On the input side of the control unit 40 of the first embodiment. Are respectively connected with an internal temperature sensor 52 for detecting the internal temperature and a temperature display 51 on the output side.
The control unit 50 is provided with a bias value calculation unit 45A and a comparison unit 46A. The bias value calculation unit 45A calculates the bias value b according to the above equation (14a), and the comparison unit 46A The temperature T0 is compared with the target value Tm obtained by subtracting [(1-γ) · bias value b] from the internal set temperature T1x, and the refrigeration apparatus 23 depends on whether the duct temperature T0 is higher or lower than the target value Tm. A function for controlling the operation and stop of the (internal fan 32) is provided.
In addition, the control unit 50 includes a correction value calculation unit 54 that calculates the display correction value TH based on the above equation (13a), and a display temperature calculation unit that calculates the display temperature based on the equation (20). 55 is provided.

  The operation of this embodiment is as follows. First, in the bias value calculation unit 45A of the control unit 50, the bias value b is calculated by substituting the ambient temperature T2, the internal set temperature T1x, and the conductivity duty of the dew proof heater 35 into the equation (14a). Then, the comparison unit 46A compares the duct temperature T0 with the target value Tm obtained by subtracting [(1-γ) · bias value b] from the internal set temperature T1x, and the duct temperature T0 is compared with the target value Tm (actually, When the temperature becomes higher than the target value Tm, the refrigeration apparatus 23 and the internal fan 32 are operated, and the duct temperature T0 is lower than the target value Tm (actually a lower limit value lower than the target value Tm). When the temperature becomes lower, the refrigeration unit 23 and the internal fan 32 are stopped. By repeating this operation, the duct temperature T0 is maintained substantially at the target value Tm as shown in FIG. The internal set temperature T1x that is higher by [(1−γ) · bias value b] than Tm, in other words, the internal temperature that is higher by the bias value b than the target value Tm is maintained.

At the same time, the correction value calculation unit 54 calculates the display correction value TH by substituting the bias value b calculated by the bias value calculation unit 45A into the equation (13a). Subsequently, the display temperature calculation unit 55 Based on the equation (20), a calculation for subtracting the display correction value TH from the internal temperature T1 is performed, that is, the internal center temperature Tc is estimated by calculation, and the temperature Tc is displayed on the temperature display unit 51. .
In the above, when any one of the ambient temperature T2, the internal set temperature T1x, and the conductivity duty of the dewproof heater 35 is changed, the bias value b is newly calculated and changed, and the target based on the new bias value b is changed. The control operation is performed while comparing the value Tm and the duct temperature T0. Further, the internal chamber temperature Tc is estimated again with the change of the bias value b, and the changed estimated temperature is displayed on the temperature display unit 51.

As described above, in the second embodiment, similarly to the first embodiment, the bias value b that is the basis of the target value necessary for the control operation is not set to a fixed value as in the conventional case, but is operated. Since it is variable to an appropriate value according to the time condition, situation, etc., the control for accurately maintaining the internal temperature T1 at the set temperature T1x can be performed quickly and accurately without causing a time lag.
Further, the temperature obtained by subtracting the display correction value TH from the internal temperature T1 detected by the internal temperature sensor 52 is regarded as the internal temperature Tc and is displayed on the temperature display unit 51. Instead of using a fixed value as in the prior art, it is variable according to the conditions and conditions during operation. Specifically, the internal temperature T1 (internal storage temperature T1x), the ambient temperature T2, and the energization rate duty of the dew proof heater 35 disposed on the front frame 17A are likely to affect the setting of the correction value TH. An appropriate value is calculated in advance based on the above, and the calculated value is applied to the display correction value TH when calculating the above-described in-compartment center temperature Tc. Thereby, the chamber center temperature Tc can be accurately displayed on the temperature display unit 51.

In the second embodiment, even if the duct temperature T0 is controlled to the target value Tm shown in the above equation (18), if the internal temperature T1 may slightly deviate from the internal set temperature T1x, the duct temperature Set the target value of T0
Target value of duct temperature T0 = in-chamber set temperature T1x-{(1-γ) · bias value b + auxiliary variable bias value} (18 ′)
In other words, the auxiliary variable bias value is included, and the auxiliary variable bias value is set to an appropriate value by feedback.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) When the bias value is calculated in the first embodiment, the detected value from the internal temperature sensor may be used as the internal temperature T1.
(2) In the above embodiment, as a heat source is out of the heat between the inside the refrigerator, and the ambient temperature has been exemplified two of anti-condensation heater that is provided on the front frame, to further add another heat source It may be.
(3) The present invention is not limited to the constant temperature and high humidity chamber exemplified in the above embodiment, but the main point is that an inner box made of a heat conducting member is accommodated in an outer box made of a heat insulating box with a duct interposed therebetween. It has a heavy structure and can be widely applied to all types of indirectly cooled storages in which the inside of the inner box is indirectly cooled by circulating cold air through the duct.

The longitudinal cross-sectional view of the constant temperature high humidity chamber which concerns on Embodiment 1 of this invention Its schematic cross-sectional view Block diagram of control mechanism Graph showing the relationship between the internal temperature and duct temperature Schematic plan view according to the second embodiment Block diagram of control mechanism Graph showing the relationship between the temperatures of each part Schematic plan view of a conventional example

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Outer box 12 ... Inner box 13 ... Storage room (inside of a warehouse) 15 ... Duct 17A ... Front frame 18 ... Heat insulation door 23 ... Refrigeration device 24 ... Compressor 32 ... Inside fan 35 ... Dew-proof heater 40 ... Control part ( Operation control means) 41 ... Duct temperature sensor 42 ... Ambient temperature sensor 43 ... Internal set temperature input section (internal set temperature input means) 45 ... Bias value calculation section (bias value calculation means) 46 ... Comparison section 50 ... Control section (Internal temperature display means) 51 ... Temperature display unit 52 ... Internal temperature sensor 54 ... Correction value calculation unit 55 ... Display temperature calculation unit

Claims (2)

An outer box comprising a heat insulating box with a front opening and a heat conducting member with a front opening accommodated in the outer box so as to form a duct between the outer box and the outer box. In an indirect cooling storage that indirectly cools the inside of the inner box by circulating cold air generated by a refrigeration device through the duct.
A duct temperature sensor for detecting the temperature in the duct;
A set temperature input means for inputting the set temperature in the inner box;
The duct temperature detected by the duct temperature sensor is compared with a target value obtained by subtracting a bias value from the internal set temperature input by the internal set temperature input means, and the refrigeration apparatus based on the comparison result And an operation control means for maintaining the inside box at the set temperature inside the box by controlling the operation of
An indirect cooling system comprising bias value calculation means for calculating the bias value based on an internal temperature , an ambient temperature, and an energization rate of a dew proof heater disposed on a front frame of the outer box. Storage. An outer box comprising a heat insulating box with a front opening and a heat conducting member with a front opening accommodated in the outer box so as to form a duct between the outer box and the outer box. In an indirect cooling storage that indirectly cools the inside of the inner box by circulating cold air generated by a refrigeration device through the duct.
An internal temperature sensor for detecting the temperature in the inner box;
A chamber temperature display means for calculating a temperature obtained by subtracting the display correction value from the chamber temperature detected by the chamber temperature sensor, and displaying the calculated value on the chamber center temperature and displaying it on the temperature display unit is provided. And
Correction value calculation means for calculating the display correction value based on the internal temperature , the ambient temperature, and the energization rate of the dew proof heater disposed on the front frame of the outer box is provided. Indirectly cooled storage.

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