KR100470564B1 - Control method for temperature and humidity of show case - Google Patents

Abstract

The present invention relates to a showcase having a cooling device using a thermoelectric element, wherein the showcase comprises: a cooling assembly for cooling air by using a thermoelectric element on which one side is endothermic and the other side generates heat according to the polarity of the supplied power; It provides a cooling device having a power supply for providing power to the thermoelectric element and a control unit for controlling the cooling assembly to control the temperature and humidity of the storage compartment.

Description

CONTROL METHOD FOR TEMPERATURE AND HUMIDITY OF SHOW CASE}

The present invention relates to a temperature humidity control method of a showcase having a cooling device using a thermoelectric element.

A typical showcase cooling device consists of a compressor, a condenser, a capillary and an evaporator, the cooling process of which circulating refrigerant is compressed to a state of high temperature and high pressure in the compressor, and the compressed refrigerant is changed to a state of low temperature and high pressure while passing through the condenser, After passing through the capillary tube, the evaporator is converted to low temperature and low pressure to exchange heat with the surrounding air to lower the temperature of the surrounding air.

This conventional cooling device has the following problems. First, since it has a structure that artificially circulates the refrigerant, a compressor for compressing the refrigerant at high temperature and high pressure is required, and noise and vibration are generated during the compression process. Second, since the freon gas that destroys the ozone layer is used as the refrigerant, environmental pollution caused by the refrigerant is caused. Third, precise temperature control is difficult because deviation of the cooling temperature occurs about 3-5 degrees. Therefore, it is impossible to maintain a precise temperature depending on the state of the object. Fifth, since only the temperature control is made, the humidity is not controlled separately, so dehumidification occurs due to the supercooling of the evaporator, and the humidity decreases, resulting in a drop in the freshness of the object and drying. Sixth, in the event of a failure of the cooling system, it is a hassle to repair after tearing off the entire showcase. In particular, since the conventional cooling apparatus has a complicated structure in which the refrigerant is circulated, it is difficult to install and has a disadvantage in that the movement is not free.

The present invention has been made to solve such a conventional problem, and an object thereof is to provide a showcase having a new cooling device which is simple to install, easy to replace and repair, and free of noise and vibration. Another object is to provide a showcase with a new environmentally friendly cooling device. Another object is to provide a method of controlling temperature and humidity of a new type of showcase that can provide a low temperature and high humidity environment.

According to a feature of the present invention for achieving the above object, the showcase is a cooling assembly for cooling the air by using a thermoelectric element is one end is endotherm and the other end is generated according to the polarity of the supplied power when the power is supplied; It provides a cooling device having a power supply for providing power to the thermoelectric element and a control unit for controlling the cooling assembly to control the temperature and humidity of the storage compartment.

According to an embodiment of the present invention, the cooling assembly is installed in close contact with one side of the thermoelectric element so as to be located on the flow path of the cooling chamber and has a plurality of cooling fins. A heat absorbing plate; A heat sink installed in close contact with the other side of the thermoelectric element and having a plurality of heat dissipation fins; A cooling circulation fan for forced circulation of cold air around the heat absorbing plate; A heat radiating fan for circulating hot air around the heat sink; It may include a heat insulating material attached to the upper surface of the heat sink and to block the heat radiation from the upper surface of the heat sink to the cooling chamber.

According to an embodiment of the present invention, the control unit includes: an operation panel in which a user inputs a desired temperature and a desired humidity and displays a temperature and humidity of a current storage room; Compared to the desired temperature and the current temperature to adjust the power provided to the thermoelectric element accordingly, and compares the desired humidity and the current humidity accordingly to adjust the rotational speed of the cooling circulation fan according to the microcomputer to control the PID temperature can do.

According to an embodiment of the present invention, the cooling device has a moisture-proof insulation means for preventing the thermoelectric element from being damaged by an electrical short circuit due to condensation occurring on the cold side and the hot side according to the air temperature change around the thermoelectric element. . The moisture-proof heat insulating means includes a sealing block surrounding the thermoelectric element between the heat absorbing plate and the heat sink so that the thermoelectric element is blocked from contact with the air; A seal sealing the heat absorbing plate and the sealing block and the heat sink and the sealing block; And an exhaust port for removing air in the inner space sealed by the sealing block.

According to an embodiment of the present invention, for the rapid heat transfer from the thermoelectric element to the heat absorbing plate, further comprising a copper plate and a thermal grease (thermal grease) installed between the heat absorbing plate and the thermoelectric element, in the thermoelectric element Sucker into the heat sink Further comprising: a copper plate and a thermal grease installed between the heat sink and the thermoelectric element for faster heat transfer; The copper plate is bonded to the thermoelectric element, the heat absorbing plate, and the heat sink by vacuum brazing.

According to an embodiment of the present invention, the case has a bottom plate on which the cooling device is mounted and which forms the bottom surface of the cooling chamber; The bottom plate is inclined, the bottom plate is a mounting hole in which the cooling device is mounted so that the heat absorbing plate is located on the flow path of the cooling chamber, and the heat sink is located below the bottom plate, and water generated from the cooling device. A drain groove includes a drain groove flowing along the inclined surface of the bottom surface, the drain groove is mounted to the drain groove for storing the water.

According to another feature of the invention, the temperature and humidity control method of the showcase comprises the steps of inputting the desired temperature and humidity through the operation panel; Checking the current temperature and humidity from the temperature sensor and the humidity sensor; Receiving the value of the temperature sensor and determining and cooling a primary cooling temperature; Comparing whether the temperature of the temperature sensor has reached a primary cooling temperature; Setting a secondary set temperature when the temperature of the temperature sensor reaches the primary cooling temperature and maintaining the storage chamber at the secondary set temperature; Checking the current humidity from the humidity sensor; If the current humidity is higher than the desired humidity, automatically controlling the rotation speed of the cooling circulation fan so that the circulation speed of the internal air is automatically adjusted to obtain a dehumidifying effect; If the current humidity is lower than the desired humidity may include controlling the dehumidification effect by automatically controlling the rotational speed of the cooling circulation fan to automatically adjust the circulation speed of the internal air. All.

In the showcase according to the present invention, the cooling device is a method of applying a gas state diagram of air, and the microcomputer stores a calculation formula of air state values for temperature and humidity in advance, thereby determining the amount of cooling suitable for the final humidity during cooling. The cooling temperature is determined by feeding back the value of the humidity sensor to match the final desired humidity value, and the thermoelectric element is heated again to meet the set temperature. To control. When a certain temperature and humidity range is reached, temperature control is calculated while humidity control is finely adjusted to the air volume.

According to the present invention, since the cooling device is operated using electricity, it is an environment-friendly device. In addition, in controlling the room temperature, the temperature deviation is always maintained at a constant temperature of 1 degrees or less, and precise temperature control and humidity control are possible, so that the stored product can be kept fresh without being quickly dried. In addition, the failure rate of the product is significantly lower than in the past (simple configuration). In case of failure, the assembly of the broken parts can be removed and repaired without tearing the showcase of the showcase.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 8. In addition, in the drawings, the same reference numerals are denoted together for components that perform the same function.

1 and 2, the showcase 100 according to the embodiment of the present invention has a case 110 and a cooling device 130. The case 110 is provided with a shelf or the like inside the storage compartment 112 for storing and displaying the goods at a low temperature, and below the storage compartment 112. And a cooling chamber 114 formed in the space to cool the air introduced from the storage chamber 112 and the outside, and a flow path 116 formed so that air circulates through the cooling chamber 114 and the storage chamber 112. .

The case 110 is provided with a suction port 117 on one side of the bottom plate 112a constituting the storage compartment 112 and air from the outside into the cooling chamber 114, and the other side. The discharge port 118 through which the air cooled in the cooling chamber 114 flows out into the storage chamber 112 through the flow path 116 is provided. Here, the position of the flow path 116, the suction port 117 and the discharge port 118 and the shape of the case 110 is not limited to this embodiment can be variously changed / selected of course.

In the cooling chamber 114, the cooling device 130 for cooling the air introduced into the cooling chamber 114 is installed. The bottom plate 114a forming the bottom of the cooling chamber 114 is inclined to the rear end so that water, which may be generated by supercooling, may flow to the rear end of the cooling unit 132. The bottom plate 114a has a mounting hole 114c on which the cooling unit 132 of the cooling device is mounted, and a drain groove 114b formed at a position spaced apart from the mounting hole 114c. For example, the water generated in the cooling unit 132 flows along the inclined bottom surface and is collected in the drain groove 114b, and the water collected in the drain groove 114b forms a hole formed in the drain groove 114b. The drain is discharged to the drain tank 114d mounted on the bottom surface of the bottom plate 114.

The cooling device 130 is a device using a thermoelectric element is one end is endotherm, the other side is heat generated according to the polarity of the power supplied when the power is supplied, the cooling unit 132, and the power supply The unit 180 and the controller 190 are largely configured.

3 is an exploded perspective view of the cooling unit 132 of the cooling device 130, a front cross-sectional view of the cooling unit and FIG. 5 is a cross-sectional view taken along the line 5-5 shown in FIG. It is. 3 to 5, the cooling unit 132 includes a thermoelectric element 134, a heat absorbing plate 138, a heat sink 140, a cooling circulation fan 142, a heat radiating fan 144, and a heat insulating material 146. , Moistureproof insulation means 150, and the upper cover 148a and the lower cover (148b), they are made of one assembly.

The heat absorbing plate 138 is installed in close contact with one side (heat absorbing side) of the thermoelectric element 134 and has a plurality of cooling fins 138a. The heat dissipation plate 140 is installed in close contact with the other side (heat dissipation side) of the thermoelectric element 134, and has a plurality of heat dissipation fins 140a. The cooling circulation fan 142 is installed in front of the heat absorbing plate 138 to forcibly circulate cold air around the heat absorbing plate 138. The speed of the cooling circulation fan 142 is controlled by the controller 190. A temperature sensor 172 and a humidity sensor 174 are positioned behind the heat absorbing plate 138 corresponding to the cooling circulation fan 142, and these sensors 172 and 174 are fixed on the upper cover 148a. Is installed. Data read from the sensors is provided to the controller 190. The heat dissipation fan 144 is installed in front of the heat dissipation plate 140 to forcibly circulate the hot air around the heat dissipation plate 140.

The heat insulating material 146 is installed on an upper surface of the heat sink 140. The heat insulator 146 prevents hot heat from rising from the heat sink 140 to the cooling chamber.

On the other hand, the cooling device 130 according to the present invention has a heat transfer structure for increasing the heat transfer efficiency from the thermoelectric element 134 to the heat absorbing plate 138 and the heat sink 140. Referring to FIG. 6, a copper plate 136 and a thermal grease 137 are stacked and installed between the thermoelectric element 134 and the heat absorbing plate (or heat sink), and they are vacuum brazed (heat / press applied). By mutually bonding in a manner to increase the heat transfer efficiency from the thermoelectric element 134.

In general, in a cooling device using a thermoelectric element, condensation is generated on the cold side and the hot side according to the temperature change of the outside air, and electrical short occurs by the condensation. In the present invention, there is provided a moisture-proof insulation means 150 for preventing damage (breakage) of the thermoelectric element due to such condensation. The moisture-proof heat insulating means 150 includes a sealing block 152 (may use a heat insulating material) for blocking the contact of the thermoelectric element 134 with the atmosphere containing humidity, the sealing 154 and the exhaust port. Has 156. The sealing block 152 is installed to surround the thermoelectric element 134 between the heat absorbing plate 138 and the heat sink 140. The sealing 152 is installed between the heat absorbing plate 138 and the sealing block 152 and between the heat sink 140 and the sealing block 152. Thus, in the state where the thermoelectric element 134 is sealed using the sealing block 152 and the sealing 154, air in the sealed space 157 (shown in FIG. 5) is finally discharged to the exhaust port 156. By force), the sealed space 157 is vacuumed. As such, since the thermoelectric element is positioned in the vacuum space, the cooling device 130 may prevent condensation due to temperature change during the cooling process. It is.

The thermoelectric element and the cooling circulation fan are controlled by the controller in the cooling unit having the configuration as described above.

Looking at the controller 190 in more detail with reference to FIG. 7, the controller 190 includes an operation panel 192 in which a user inputs a desired temperature and humidity and displays a current temperature and humidity, and the thermoelectric element. The microcomputer 194 and the AD / converter 195 and the inverter circuit 196 which control the power provided to the power source 134 and adjust the rotational speed of the cooling circulation fan 142 and PID temperature control. A converter 197 and the like.

7 and 8, the temperature and humidity control in the showcase 100 according to the present invention is performed as follows. First, the desired temperature and humidity are input through the operation panel 192. (S110) The input temperature and humidity values are transmitted to the microcomputer 194. The temperature sensor 172 and the humidity sensor 174 check the current temperature and humidity (S120) and provide the data to the A / D converter 195. The A / D converter 195 receives an analog signal sent from the sensors and converts the analog signal into a digital signal and provides it to the microcomputer 194. The microcomputer 194 sets a primary cooling temperature by receiving a value of a temperature sensor (S130), and then determines and provides a power provided to the thermoelectric element. When the power supply process to the thermoelectric element is specifically described, the microcomputer 194 performs PID temperature control. The microcomputer 194 stores a calculation formula of air state values for temperature and humidity in advance. Thus, the value entered from the A / D converter 195 is the operation A signal for processing to maintain the temperature and humidity set in the panel 192 is sent to the D / A converter 197 and the inverter circuit 196. The D / A converter 197 converts the digital signal sent from the microcomputer 194 into an analog signal and sends it to the power supply unit 180. The power supply unit 180 performs the heating / cooling output by the forward / reverse output, and supplies power to the thermoelectric element according to a signal received from the D / A converter.

The thermoelectric element 134 cools and heats the heat absorbing plate and the heat sink by the power supplied from the power supply unit 180. On the other hand, the microcomputer compares whether the temperature of the temperature sensor 172 has reached the primary cooling temperature (S140), and if so, sets the secondary set temperature in the microcomputer 194, the storage chamber as the secondary set temperature The temperature control is performed by maintaining the temperature (S150). The microcomputer 194 receives the current humidity from the humidity sensor 174 (S160), and accelerates the cooling circulation fan 142 when the current humidity is high. To obtain a dehumidifying effect (S200). On the contrary, when the humidity is low, the cooling circulation fan 142 is decelerated (S180). If the current humidity is the same as the desired humidity, the speed of the current cooling circulation fan is maintained. (S190) The inverter circuit 196 changes the rotation speed of the cooling circulation fan 142 by frequency modulation, and the microcomputer 194 Humidity is adjusted by adjusting the number of rotations of the cooling circulation fan 142 according to the signal received from the). As described above, the cooling device 130 of the present invention adjusts the rotation speed of the cooling circulation fan according to the high and low humidity, and the humidity inside the case is controlled by the amount of air.

Here, the structural feature of the present invention, for improving the thermal conductivity efficiency of the thermoelectric element It has a heat transfer structure. Another feature is to have a moisture-proof insulation structure for preventing damage to the thermoelectric element due to condensation. Another feature of the present invention is to control the cooling temperature and at the same time receive the value of the input humidity sensor to maintain the state of the air at an unsaturated temperature to have a control method that can maintain the humidity of more than 60% at the cooling temperature.

The structural feature of the present invention is that the rotation speed of the cooling circulation fan is adjusted according to the high and low humidity. According to this feature, it is possible to obtain the effect that the humidity inside the showcase is controlled by the air volume.

In the above, the configuration and operation of the showcase according to the present invention has been shown in accordance with the above description and drawings, but this is merely an example, and various changes and modifications are possible without departing from the technical spirit of the present invention. .

Applying the present invention as described above can obtain the following effects.

First, since the cooling unit can be attached and detached, it is easy to install, replace, and repair the cooling unit. Second, there is no noise and vibration in the cooling device. Third, it is an environmentally friendly device that does not use freon gas. Fourth, it is possible to provide a low-temperature and humid environment by adjusting the cooling temperature and maintaining a state of air at an unsaturated temperature by receiving feedback from the input humidity sensor at the same time. Fifth, the thermal conduction efficiency of the thermoelectric element is high, and thus power consumption can be reduced. Sixth, damage to the thermoelectric element due to condensation can be prevented. Therefore, the product life is long.

1 is a perspective view of a showcase according to a preferred embodiment of the present invention;

2 is a front sectional view of a showcase according to a preferred embodiment of the present invention;

3 is an exploded perspective view of the cooling unit shown in FIG. 2;

4 is a front sectional view of the cooling unit shown in FIG. 3;

5 is a cross-sectional view taken along line 5-5 shown in FIG. 4;

6 is an enlarged view illustrating main parts of an electrothermal structure of a thermoelectric element;

7 is a configuration block diagram for temperature and humidity control in the cooling apparatus of the showcase according to the preferred embodiment of the present invention;

8 is a flowchart illustrating a method for controlling temperature / humidity of a showcase according to an exemplary embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

130: cooling unit

132: cooling unit

134: thermoelectric element

138: heat absorbing plate

140: heat sink

142: cooling circulation fan

144: heat dissipation fan

146: Insulation

Claims (9)

delete delete delete delete delete delete delete delete A case in which a flow path is formed so that a storage compartment, a cooling chamber, and cold air circulate through the storage compartment and the cooling chamber; A cooling device mounted on the cooling chamber flow path of the case to exchange heat with the internal air of the storage compartment to cool the air; The cooling device includes a cooling assembly for cooling air by using a thermoelectric element on which one side is endothermic and the other side generates heat according to the polarity of the supplied power when the power is supplied; A power supply unit providing power to the thermoelectric element; A control unit controlling the cooling assembly to control temperature and humidity of the storage compartment; And moisture-proof insulation means having a sealing block surrounding the thermoelectric element between the heat absorbing plate and the heat sink so that the thermoelectric element is blocked from contact with the air. Inputting a desired temperature and humidity through the operation panel; Checking the current temperature and humidity from the temperature sensor and the humidity sensor; Receiving the value of the temperature sensor and determining and cooling a primary cooling temperature; Comparing whether the temperature of the temperature sensor has reached a primary cooling temperature; Setting a secondary set temperature when the temperature of the temperature sensor reaches the primary cooling temperature and maintaining the storage chamber at the secondary set temperature; Checking the current humidity from the humidity sensor; An automatic dehumidification temperature setting step of comparing the preset humidity value with the desired humidity to make the temperature and the humidity unloaded; If the current humidity is higher than the desired humidity, controlling the dehumidification effect by automatically controlling the rotation speed of the cooling circulation fan to automatically adjust the circulation speed of the internal air; And controlling the dehumidification effect by automatically controlling the rotational speed of the cooling air by automatically controlling the rotational speed of the cooling circulation fan when the current humidity is lower than the desired humidity.