KR20180041277A - Low temperature storage having dual temperature controller - Google Patents

Abstract

The present invention relates to a low temperature storage including a first temperature control device for controlling a cooling unit such that a temperature in a room maintains a preset first temperature. The first temperature control device comprises: a first temperature sensor for measuring a temperature in the room; a first control unit for receiving the temperature measured in the first temperature sensor and outputting a signal for operating a cooling unit if the measured temperature exceeds the preset first temperature; a second temperature sensor including a switch box having a first switch for receiving the signal output from the first control unit to operate the cooling unit and measuring the temperature in the room; a second control unit for receiving the temperature measured in the second temperature sensor and outputting a signal for operating the cooling unit if the measured temperature exceeds a preset second temperature; and a second temperature control device including a relay box having a second switch for receiving the signal output from the second control unit to operate the cooling unit. The relay box of the second temperature control device is electrically connected to the switch box in parallel to operate the cooling unit, wherein the first temperature is different from the second temperature.

Description

{Low temperature storage having dual temperature controller}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a low-temperature storage tank, and more particularly, to a low-temperature storage tank having a double temperature control device for preventing malfunction of a conventional temperature control apparatus.

The present invention has been made from research carried out as part of the Export Strategic Technology Project of the Ministry of Agriculture, Forestry, and Livestock. [Reference: 114094-2, Title: Development of technology for quality control and monitoring after exporting paprika Postharvest Paprika for export and its on site application)].

As the demand for dietary products of consumers increases due to the economic development and demand for diverse foods, the demand for distribution of fresh foods is increasing. Also, from the viewpoint of producers of concentrated fisheries, the necessity of shipment adjustment and storage after production is increased, There is an increasing demand for low temperature storage that can be stored.

1 and 2 are views showing a general structure of a low temperature reservoir. Here, the low temperature reservoir of FIG. 1 and FIG. 2 is an example taken from Korean Patent No. 10-1142457 of 'Patent Document 1'.

The low temperature storage tank shown includes a bottom body 11, a storage body formed of a wall part 12 and a ceiling part 13 formed on the bottom part 11, a heater and a cooling unit 20, a curing fan 30, a curing exhaust fan 40, a motor-driven shutter 50, a control unit 60, and an energy generating unit 80.

The heater and the cooling unit 20 have a unit body 21 fixed to the ceiling portion 13 by a bracket 21a, a unit fan 22 installed on one side of the unit body 21, A cooling unit 23 having an evaporator (not shown) installed inside the unit main body 21 so as to be spaced apart from the unit fan 22 and a heater installed so as to be apart from the unit fan 22 inside the unit main body 21 do.

The curing fan 30 is installed in the ceiling portion 13 so as to be spaced apart from the heater and the cooling unit 20 and serves to circulate the coolant and the warm air generated in the heater and the cooling unit 20 in the main body of the storage.

At least one curing exhaust fan 40 is installed in the wall part 12 and discharges carbon generated during the curing process of stored crops.

As shown in FIG. 2, at least one electric supply shutter 50 is installed in the wall part 12, and serves to guide fresh outside air into the inside of the storage body.

The control unit 60 is electrically connected to the heater and the cooling unit 20, the curing fan 30, the curing exhaust fan 40 and the motor-driven shutter 50 to control the above-described components under a given condition do.

The energy generating unit 80 includes a solar collecting unit 90 installed on the roof of the storage tank main body and preferably a storage battery and an inverter installed in the storage tank main body 10 so as to maintain the temperature of the low temperature storage tank All or a part of the required energy is obtained from the sunlight.

This low-temperature storage facility has a function of preserving fresh stored long-term storage by keeping the concentrated aquatic product at a freezing point (0 ° C) or more by cooling the inside of the room which is an insulating space, and is a facility for compressing, condensing, expanding, In terms of applying the refrigeration cycle, the technical principles are the same as those of air conditioning, freezing and freezing warehouses, and large refrigeration warehouses. However, there are differences in detailed devices, structures and control methods depending on the characteristics of the application target.

Freezing warehouses and freezers are freezing and storing the stored products, so that keeping the temperature below the freezing point hardly causes abnormalities in the quality of the stored products.

However, the low temperature reservoirs are required to store various kinds of concentrated aquatic products at a temperature above the freezing point. Especially, in the case of agricultural products, since they are required to be kept alive in fresh condition, the uniformity of temperature is not maintained, If it is not precisely controlled, it causes low temperature disruption due to excessive cooling and deterioration due to respiratory physiological action. In some cases, a 10-30% reduction rate is generated, which increases the distribution cost of fresh foods.

In addition, small- and medium-sized low-temperature storage is not different from general household refrigerator or large warehouse-type low-temperature storage for the purpose of storing fresh food, but it is required to maintain the temperature and humidity accuracy and uniformity within a relatively large space. This is a large warehouse type that can apply high efficiency management technology such as liquid liquid pump system and cool air supply through duct, including a method of centralized and precise control using a computer. It is also different from the cold storage.

Since small and medium-sized low-temperature storage is used for industrial or commercial purposes, it requires a higher level of uniformity and precision than that of general household refrigerators.

In addition, it operates independently in a small scale in areas where it is difficult to acquire expertise in refrigerators, such as concentrated fisheries producers and market or group foodservice stations. Therefore, it is safe to use, manage and maintain the quality of stored products by automatic operation control without expert operation knowledge. Management technology is required.

These characteristics lead to the following limitations in the direct application of technologies related to general refrigeration and general air conditioning, in which large-scale freezing low-temperature warehouses or large-scale investments are made in technology development.

First, if the temperature inside the room is not uniform in a low - temperature storage room, some storage materials may be exposed to the East Sea and some may be exposed to a high temperature, thereby degrading the storage quality. Therefore, the uniformity of temperature and humidity should be maintained at a higher level than that of a general household refrigerator. After the temperature stabilization, the deviation between the highest temperature and the lowest temperature should be within ± 2 ° C and the deviation between the highest and lowest temperatures should be within ± 5 ° do.

Second, agricultural products stored in a living state are required to be precisely controlled within 0.5 ° C in order to maintain the optimum storage temperature. Therefore, the set temperature and the minimum temperature deviation inside the room should be kept within ± 1 ℃ in normal operation and ± 3 ℃ in case of failure.

Third, low - temperature storage is more expensive than general household refrigerator because of high refrigeration load, which leads to increase of storage cost. Therefore, it is required that the power consumption is low in terms of reduction of maintenance cost and reduction of CO ₂ .

In this way, the low temperature storage requires fast cooling time, high level of temperature uniformity, control precision and energy efficiency in terms of the quality of the storage and the maintenance cost. These performances are required for the control algorithm suitable for low temperature storage, It is directly related to the timing of the defecation.

For large low-temperature storage facility in relation to the control algorithm, Korea Patent Registration No. 10-0332481 arc as suggested in the "moving image environment manager for low-temperature reservoir and this low temperature storage with", in consideration of the environment inside the CO ₂ storage control management . However, these control techniques are not suitable for small and medium-sized low-temperature reservoirs as mentioned above.

Therefore, most of the small and medium-sized low-temperature storage rooms are compared with the "set temperature" and the "room internal temperature + set refrigeration deviation" to perform the freezing operation if the set temperature + freezing deviation> (ON-OFF method) and a time-period control method, in which the freezing operation is stopped and the defrosting is repeated for a predetermined time (about 20 minutes or less) at every predetermined time (about 4 hours) (Korea Patent No. 10-0747068). However, it can be satisfied with the cooling time, temperature uniformity inside the room, control precision and energy consumption efficiency. There was a limit to the performance.

A study on the optimal design of a medium low temperature reservoir using Neuro-Fuzzy control system, Ministry of Agriculture and Forestry, August 2003) adjusted the opening of EEV (Electrical Expansion Valve) to control the pressure of refrigerant supplied to the evaporator, And controlling the driving motor of the wind speed and humidifier to control the flow rate and humidity of the cool air in the storage space, thereby shortening the time required for cooling and precisely controlling the temperature inside the room. However, It is recognized that the defrosting by the heater at the time intervals is repeated, and thus the defrosting heat inside the room and the periodic temperature rise due to the defrosting are difficult to solve.

In order to keep the agricultural products in an optimal state in a low-temperature storage room, it is required to be precisely controlled within 0.5 DEG C, and various control algorithms are continuously being developed for this purpose.

However, prior to the development of the control algorithm, it is hardware reliability of the temperature control device provided in the low temperature reservoir. In other words, no matter how good the temperature control algorithm provided by software is, it should be premise that the hardware temperature control device will not malfunction.

Accordingly, there is a great need to provide a new method for increasing the hardware reliability of the temperature control device provided in the low temperature storage.

Korean Registered Patent No. 10-1142457 (Announcement of May, 2012) Korean Patent No. 10-0332481 (issued Apr. 14, 2002) Korean Registered Patent No. 10-0747068 (2007.08.07 Announcement)

 A Study on the Optimal Design of a Medium Low Temperature Reservoir using Neuro-Fuzzy Control System (Koh Hak Kyun et al., August 2003 Ministry of Agriculture and Forestry)

It is an object of the present invention to provide a method of greatly reducing a concern that a temperature control device provided in a low-temperature reservoir malfunctions.

The present invention relates to a low temperature reservoir including a first temperature controller for controlling a cooling unit so that a temperature inside a room maintains a predetermined first temperature, wherein the first temperature controller measures a temperature inside the room A first temperature sensor for receiving a temperature measured by the first temperature sensor and outputting a signal for activating the cooling unit when the measured temperature exceeds a predetermined first temperature, 1 control unit and a distribution box having a first switch for receiving the signal output from the first control unit and operating the cooling unit, wherein the second temperature sensor measures a temperature inside the room, And a controller for receiving a measured temperature from the temperature sensor and outputting a signal for activating the cooling unit when the measured temperature exceeds a predetermined second temperature Further comprising a second temperature controller including a second controller and a relay box having a second switch for receiving the signal output from the second controller to operate the cooling unit, Wherein the relay box is electrically connected to the distribution box in parallel to operate the cooling unit, and the first temperature and the second temperature are different from each other.

The first temperature corresponds to the temperature inside the room desired by the user, and the second temperature is higher than the first temperature.

In one embodiment of the present invention, the second temperature may be set to be higher by about 1 DEG C than the first temperature.

The first temperature sensor and the second temperature sensor are preferably arranged to measure the temperature inside the room at substantially the same point.

The low-temperature tank of the present invention having the above-described structure is provided with the dual temperature control device, so that even if one of the temperature control devices malfunctions, the other temperature control device compensates for it and operates normally to maintain the temperature of the low- have. Accordingly, it is possible to prevent a large amount of stored goods from being damaged due to an abnormal state of the room internal temperature due to a malfunction of the temperature control device.

In addition, the low temperature reservoir of the present invention can prevent the hysteresis phenomenon in which the dual temperature regulator frequently operates by setting the target temperature in each temperature regulator of the dual temperature regulator differently and minutely.

Also, by setting the target temperature in each temperature control device of the double temperature control device to a minute difference of about 1 DEG C, even if one of the temperature control devices malfunctions, it does not deviate greatly from the target temperature deviation, The quality of the stored product can be maintained satisfactorily.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view schematically illustrating the structure of a low temperature reservoir according to the prior art; FIG.
FIG. 2 is a plan view showing a state in which the low temperature reservoir shown in FIG. 1 is viewed from above. FIG.
Figure 3 schematically illustrates the structure of a low temperature reservoir according to the present invention;
FIG. 4 is a view showing a configuration and a connection state of the dual temperature control device provided in the low temperature reservoir of FIG. 3; FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments of the present invention, a description of well-known structures that can be easily understood by those skilled in the art will be omitted so as not to obscure the gist of the present invention. In the drawings, like reference numerals refer to like elements throughout. The same elements will be denoted by the same reference numerals even though they are shown in different drawings. Referring to the drawings, The size of the elements, etc., may be exaggerated for clarity and convenience of explanation.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; coupled "or" connected "indirectly while intervening in the context of the present invention.

FIG. 3 is a view schematically showing the structure of a low-temperature storage tank according to the present invention, FIG. 4 is a view showing the structure of a double temperature control device provided in the low-temperature storage tank of FIG. 3 and its connection state, The invention will now be described in detail.

As shown in the drawing, the low-temperature storeroom 100 according to the present invention includes a bottom portion 112 constituting a basic structure of a structure, a wall portion 114 surrounding the outer portion of the bottom portion 112, And a ceiling portion (116) for making the ceiling portion (116).

As described above, the storage body 110 may have a general warehouse shape. However, the storage body 110 may be an example structure and may have a completely different structure, for example, a dome structure or the like. That is, the reservoir body 110 may be provided with a space (room) for accommodating various kinds of concentrated aquatic products stored therein in a low-temperature environment.

However, the storage body 110 may be provided with a heat insulating material such as a bottom part 112, a wall part 114, and a ceiling part 116 so that a low temperature environment artificially formed inside the room can be energy- It is desirable to install it.

The cooling unit 120 is configured to produce cold air inside the room of the low-temperature storeroom 100 to adjust the temperature environment lower than the external temperature. The cooling unit 120 may be a general cooler that circulates refrigerant through a flow path connected to an evaporator, a condenser, a compressor, or the like.

The cool air produced by the cooling unit 120 is blown into the space inside the storage body 110 by the electric fan 122 to circulate the internal air so that the internal space of the room has a uniform temperature distribution.

The low temperature storage 100 of the present invention includes a first temperature control unit 130 for controlling the cooling unit 120 so that the temperature inside the room is maintained at a predetermined first temperature.

The first temperature controller 130 includes a first temperature sensor 132 for measuring the temperature inside the room and a temperature inside the room measured by the first temperature sensor 132 is controlled by the first controller 134, Lt; / RTI >

The first control unit 134 outputs a signal for activating the cooling unit 120 when the temperature inside the room received from the first temperature sensor 132 exceeds a preset first temperature, The temperature inside the cold storage room 100 is maintained at the set temperature by controlling the operation of the cooling unit 120 to be stopped.

The control algorithm of the first controller 134 may be simplified by the on / off control as described above. However, it is a conceptual explanation. It is needless to say that various target value control algorithms such as PID control and fuzzy control can be applied .

A signal output from the first control unit 134 to operate the cooling unit 120 is transmitted to the cooling unit 120 through the distribution box 136. [ The distribution box 136 is provided with a first switch such as a relay, and power is supplied through the first switch to operate the cooling unit 120.

The first temperature controller 130 controls the operation of the cooling unit 120 that supplies cool air to the low temperature storage 100 so that the temperature controller inside the room can maintain a desired temperature. . However, such a first temperature regulating device 130 can not exclude the possibility of malfunction.

As described above, if the temperature inside the room is not uniform in the low-temperature storeroom 100, some of the stored materials may be exposed to high temperatures and some of them may be exposed to high temperatures, thereby lowering the preservation quality. Deviations between temperature and minimum temperature should be maintained within ± 2 ° C.

In addition, since live agricultural products are required to be precisely controlled to within 0.5 ° C in order to maintain the optimum storage temperature, the set temperature and the minimum temperature variation inside the room should be maintained within ± 1 ° C in normal operation.

Especially, in the case of agricultural products, since it is required to keep it alive in fresh condition, if the temperature uniformity is not maintained or if the storage temperature control is not precisely controlled within 0.5 ° C, it causes low temperature disruption due to excessive cooling and deterioration due to respiratory physiology, In some cases, a 10-30% reduction rate is generated, which increases the distribution cost of fresh foods.

Therefore, the operation of the temperature controller in the low temperature reservoir 100 requires high reliability. If the first temperature controller 130 malfunctions and the manager does not recognize it for a long time, have.

The second temperature control device 140 may compensate for the malfunction of the first temperature control device 130 even if the first temperature control device 130 does not operate normally .

The second temperature controller 140 includes a second temperature sensor 142 for measuring the temperature inside the room, a second temperature sensor 142 for receiving the temperature measured by the second temperature sensor 142, A second control unit 144 for outputting a signal for activating the cooling unit 120 when the temperature of the cooling unit 120 is higher than a predetermined temperature and a second switch for receiving the signal output from the second control unit 144 and operating the cooling unit 120, And a relay box 146 having a relay box 146. [

The relay box 146 of the second temperature controller 140 is electrically connected in parallel to the distribution box 136 connected to the first temperature controller 130 to operate the cooling unit 120.

In particular, the present invention is characterized in that the first temperature set in the first temperature regulating device 130 and the second temperature set in the second temperature regulating device 140 are set differently from each other.

For example, the first temperature set in the first temperature regulating device 130 is set to a value corresponding to the temperature inside the room desired by the user, and the second temperature set in the second temperature regulating device 140 is set to The temperature is set to be slightly higher than the first temperature, which is the temperature actually desired by the user.

If the first temperature set in the first temperature controller 130 and the second temperature set in the second temperature controller 140 have different values, the low temperature reservoir 100 ) Is improved.

For example, the case where the first temperature is set to 5 占 폚 and the second temperature is set to 6 占 폚 will be described.

When the first temperature controller 130 and the second temperature controller 140 operate normally, the second temperature controller 140 detects the temperature inside the room measured from the second temperature sensor 142 When the temperature reaches 6 ° C. set to the second temperature, the second control unit 144 stops the operation of the cooling unit 120.

Even so, the first controller 134 of the first temperature controller 130 continues to operate the cooling unit 120 because the temperature inside the room has not yet reached 5 ° C, which is set to the first temperature, The temperature is reached and maintained at the user desired 5 ° C.

This dual control is possible because the relay box 146 of the second temperature regulator 140 is electrically connected in parallel to the distribution box 136 connected to the first temperature regulator 130. That is, the control signal of the first control unit 134 and the control signal of the second control unit 144 may be superimposed on each other and supplied to the cooling unit 120.

In the present invention, the first temperature set in the first temperature controller (130) and the second temperature set in the second temperature controller (140) have different values, When the temperature is set to be the same, a minute difference (deviation of measured values depending on the sensor specification, installation position, etc.) occurs in the temperature value inside the room measured by the first temperature sensor 132 and the second temperature sensor 142 This is because the operation of the cool unit is likely to cause repeated hysteresis at a narrow temperature range.

If the second thermostat 140 malfunctions, then the first thermostat 130 may operate normally and the temperature inside the room may be maintained at 5 ° C.

On the contrary, when the first temperature controller 130 malfunctions, the temperature inside the room is maintained at 6 ° C., which is the second temperature set in the second temperature controller 140.

Therefore, the low-temperature storage tank 100 of the present invention has a problem in low-temperature maintenance only when the first temperature regulating device 130 and the second temperature regulating device 140 malfunction at the same time, In the case where the apparatus malfunctions at the same time, the reliability of one of the temperature control apparatuses can be improved considerably because the temperature control apparatus is largely lowered in proportion to the probability of malfunctioning.

The structure in which the first temperature controller 130 and the second temperature controller 140 are connected in parallel to the cooling unit 120 includes a separate device for diagnosing or monitoring the malfunction of each temperature controller It is possible to cope with a malfunction without addition. Accordingly, the present invention has an advantage that it can be easily applied to a conventional temperature control device installed in a low temperature reservoir.

Here, the present invention is described as an embodiment in which a second temperature controller 140 is additionally provided in parallel to the existing first temperature controller 130, but technically, the third and fourth temperatures It is of course possible to add a regulator, and the more thermostats added, the greater the reliability will be.

However, the number of additional thermostats will need to be decided at a level that is technologically realistic considering the additional cost and the probability that all thermostats will cause malfunction at the same time.

In describing one embodiment of the present invention, it is assumed that the second temperature is set to be higher than the first temperature by about 1 DEG C. This is because the measurement error of the conventional temperature sensor and the temperature required for the low temperature reservoir 100 It is preferable that the second temperature is higher by about 1 캜 than the first temperature in consideration of the deviation.

The first temperature sensor 132 and the second temperature sensor 142 are preferably arranged to measure the temperature inside the room at substantially the same point. That is, it is advantageous to control the error of the temperature measurement value due to the difference in position in which the first temperature sensor 132 and the second temperature sensor 142 are installed.

Here, "substantially the same point" means that the first temperature sensor 132 and the second temperature sensor 142 are disposed in complete close contact with each other, except for the limitation due to the size or the installation structure of the temperature sensor, Which means that it is acceptable to measure the temperature at the same point.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It will be possible. Accordingly, the scope of the present invention will be determined by the description of the claims and their equivalents.

100: low temperature storage tank 110: storage tank main body
112: bottom part 114: wall part
116: Ceiling part 120: Cooling unit
122: electric fan 130: first temperature control device
132: first temperature sensor 134: first control section
136: Distribution box 140: Second thermostat
142: second temperature sensor 144: second control section
146: Relay box

Claims (4)

A low temperature reservoir comprising a first temperature controller for controlling a cooling unit so that a temperature inside a room maintains a first predetermined temperature, wherein the first temperature controller includes a first temperature sensor A first controller for receiving a temperature measured by the first temperature sensor and outputting a signal for activating the cooling unit when the measured temperature exceeds a predetermined first temperature; And a first switch for receiving the signal output from the first control unit to operate the cooling unit, the low temperature reservoir comprising:
A second temperature sensor for measuring a temperature inside the room; and a control unit for receiving a temperature measured by the second temperature sensor and outputting a signal for activating the cooling unit when the measured temperature exceeds a predetermined second temperature And a relay box having a second control unit for receiving the signal output from the first control unit and a second switch for operating the cooling unit by receiving the signal output from the second control unit,
Wherein the relay box of the second temperature control device is electrically connected to the distribution box in parallel to operate the cooling unit, wherein the first temperature and the second temperature are different from each other. The method according to claim 1,
Wherein the first temperature corresponds to a temperature inside the room desired by the user, and the second temperature is higher than the first temperature. 3. The method of claim 2,
Wherein the second temperature is 1 DEG C higher than the first temperature. The method according to claim 1,
Wherein the first temperature sensor and the second temperature sensor are arranged to measure a temperature inside the room at substantially the same point.

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