AU2002328811B2

AU2002328811B2 - Method and device for air-conditioning a showcase

Info

Publication number: AU2002328811B2
Application number: AU2002328811A
Authority: AU
Inventors: Thomas Hahn
Original assignee: Glasbau Hahn GmbH
Current assignee: Glasbau Hahn GmbH
Priority date: 2001-06-13
Filing date: 2002-06-12
Publication date: 2008-01-10
Anticipated expiration: 2022-06-12
Also published as: JP2009162479A; DE10128348A1; JP2004528142A; DE50209294D1; EP1399047A1; DE10128348B4; WO2002100218A1; DK1399047T3; ES2278953T3; EP1399047B1

Description

DECLARATION

I, Carole Jean Metcalfe, of 17 Forbes Crescent, Larbert, FK5 3LX, Scotland, do hereby certify that I am conversant with the English and German languages and am a competent translator thereof and that that the following is a true and correct translation made by me into the English language of the documents in respect of PCT application number EP02/06426.

Signed this 22 nd day of November 2003 METHOD AND DEVICE FOR AIR-CONDITIONING A SHOW CASE

O

The invention relates to methods and a device for implementing the method for O air-conditioning a show case in order to display objects, with an interior which is more or O_ 5 less hermetically sealed from the outside world, the objects being located on a supporting surface and being visible from the outside through the panes of glass of the side faces which completely or partially enclose the interior.

o00 A show case of this type is already known. Thus in the patent specification DE 00 r 38 05 212 C2, an air-conditioned show case for storing and/or displaying objects is S 10 described, in which the air losses escaping from the interior due to leaks between the Ointerior and the external surroundings are compensated for again by introducing air or also gasses from outside. The supplied air or gas is thereby filtered and kept at a prescribed temperature. In order that no toxic materials can penetrate from outside into the interior due to leakage of the latter, a slight excess pressure prevails in the interior.

The air or the gas introduced from outside are conveyed by a pump into the interior, the air humidity can thereby also be adjusted to a prescribed value by means of a cooling device. The air humidity is thereby monitored by means of a hygrostat which controls the cooling device. Further measures for monitoring and maintaining the air humidity in the interior of the known show case cannot be deduced from the mentioned publication.

Summary of the Invention In a first aspect, the present invention provides a method for air-conditioning a show case in order to display objects, said show case having an interior which is substantially hermetically sealed from the outside world, the objects being located on a supporting surface and being visible from the outside through panes of glass of side faces which enclose the interior completely or partially, said method including the step of: guiding the air located in the interior through an exchanger and cooling the air in this manner and the exchanger is closely connected to a cooling device with respect to the temperature transition, the exchanger being operated in such a manner that the difference between the higher temperature of the air of the interior and the lower temperature of the exchanger is maintained constantly at a value which is below the dew point of the air of the interior.

In a second aspect, the present invention provides a device for implementing the method described above, A1121(872803_1):PRW 2 wherein a first thermo switch is fitted in the interior which produces a signal when a prescribed temperature is exceeded, in that a second thermoswitch is fitted on the Sexchanger which produces a signal when a prescribed temperature is fallen below, and o both thermoswitches are connected directly or indirectly to a drive of the cooling device.

,O 5 An objective resides in indicating a method and a device for implementing the method for air-conditioning the interior of a show case, which requires a low outlay and has a low current consumption.

00 In addition to the simple construction, it is achieved as a particular advantage 00 that, as a result of the special type of operation of exchanger and cooling device, no 10 condensation water occurs on the exchanger which not only could possibly be discharged but also could influence the value of the air humidity which is desired in the interior of the show case. Since the temperature in the interior does not as a rule deviate very greatly from the environmental temperature of the show case and hence also the temperature gradient at the exchanger relative to the temperature of the interior of the show case is not is particularly high, the energy requirement is maintained within narrow boundaries. This effect is increased even more in that a cold accumulator is connected between the exchanger and the cooling device or the cooling device is itself configured as a cold accumulator.

Detailed Description of the Preferred Embodiments The invention is explained in more detail with reference to an embodiment which is illustrated in the drawing.

A show case has an upper part 1, which rests on a base 2. The upper part 1 comprises for example four side parts 3, at least three of which are configured as panes of glass. The upper side part 16 can likewise comprise a pane of glass but it is also conceivable that, instead of a pane of glass, a box-shaped upper part is present which covers the upper part 1 at the top and can contain a not-shown illumination device or further devices. The panes of glass concern simple panes of glass or also (multiple) insulation panes of glass. Furthermore, the interior enclosed by the side parts 3 and 16 is accessible in the known manner also from the outside, the latter serves for displaying objects which rest on a AH21(872803 I):PRW supporting surface 5 which for example forms the bottom of the interior 3 which is enclosed by the side faces 3 and 16. Also further not-shown supporting faces for displaying further objects can be located within the interior 4. The interior 4 in the closed state is hermetically or almost hermetically sealed by corresponding, not-shown means from the surroundings of the show case.

The air 6 in the interior 4 is drawn in through a fan 9 and compressed by an exchanger 8 in which cooling of the same is effected, the cooled air 7 is then supplied again to the interior 4. The exchanger 8 comprises a plate with a multiplicity of blades, past which the air to be cooled is guided, plate and blades are thereby formed from a thermally good conducting metal, for example aluminium or copper. The plate is in close communication with a cooling device 10 with respect to the heat transition. The cooling device 10 concerns a known cooling assembly, i.e.

a compressor 11 and a cooling coil, in which a cooling liquid is located which expands during heating and, when compressed by the compressor, gives out cold again. This not-shown cooling coil can be located for example in a securely closed container which is filled completely with water or another suitable liquid and is in close thermal communication with the plate of the exchanger 8. The water in this case represents not *only a transmission medium for the cold produced by the cooling device for the exchanger 8 but rather is so to speak also a cold accumulator which serves also for saving energy, the cooling device 10 in this case is configured as a closed system, a compensation container ensuring that a close contact is always ensured between the water of the cooling device and the exchanger 8 and in fact independently of the respective temperature of the water. Another configuration of the cooling device can comprise a solid metal block made of aluminium or copper, the cooling coil being guided one or more times through the metal block.

Also the metal block is in close thermal communication with the plate of the exchanger 8, the metal block itself even being able to take over the function of the cold accumulator according to size. If a heating spiral is provided in the exchanger 8 then heating of the air is also possible. In this case, the compressor 11 must be correspondingly controlled as a function of the signals of the second temperature sensor 13 in order that the air 7 leaving the exchanger 8 corresponds to the desired value of the temperature.

In the interior 4 of the show case, preferably at some distance from the outlet of the cooled air 7, a not-shown first thermoswitch is fitted which closes an electrical contact as soon as a prescribed temperature, for example 18 degrees, is achieved. A not-shown second thermoswitch is mounted on the exchanger 8, preferably on the plate of the same, which thermoswitch closes an electrical contact as soon as the temperature has dropped to a prescribed value, for example 8 degrees. The compressor 11 is thereby switched on by the first thermoswitch and the compressor 11 is switched off by the second thermoswitch. By corresponding choice of the temperature boundary values, at which the two thermoswitches respond, the difference between the higher temperature of the air in the interior 4 and the lower temperature of the exchanger 8 can be constantly maintained at a value which is below the dew point of the air in the interior 4 of the show case. In the case of this configuration, condensation cannot occur on the exchanger 8. The outside of the exchanger 8 is expediently thermally insulated. It is however conceivable also, instead of the insulation, to guide a part of the air cooled in the exchanger 8 past the outside of the exchanger 8 by means of suitable means. Due to this measure, contamination of the air in the interior of the show case by damaging vapours of the insulation material is avoided.

It is also conceivable to use a temperature sensor 12 instead of the first thermoswitch and a temperature sensor 13 instead of the second thermoswitch, which temperature sensors respectively convert temperature values into electrical values and transmit them to an electronic control device 14 connected to the latter, which control device for its part is connected to the compressor 11. The control device 14 evaluates the respective temperature values and induces the control of the compressor 11 in the already described manner. It has been assumed to date that the fan 9 constantly implements the air circulation through the exchanger at a constant capacity. It is possible also to influence the drive motor of the fan 9 by the control device 14 such that the quantity of air circulation is changed as a function of the respective temperature values according to prescribed values, as occurs already with respect to the compressor 11. By using a third temperature sensor which is fixed outwith the show case and indicates the temperature values of the surroundings of the show case to the control device 14, an optimal control of the climate in the interior 4 of the show case can be achieved. This can be the case for example when the temperature of the air surrounding the show case is subjected to great fluctuations. The control device 14 can be correspondingly programmed according to the already described functions, in that the control of compressor 11 and fan 9 is effected as a function of the temperature values of the relevant sensors 12, 13 and 15. In addition to the already mentioned temperature sensors 12, 13 and 15, dew point sensors can also be fitted in the show case which are likewise connected to the control device 14 and their signals supplement or extend the function of the control device 14. The control device 14 can also be provided in duplicate, one control device being constantly active and the second control device being effective only upon failure of the first control device.

In the show case, the described devices, such as exchanger 8 with fan 9 and cooling device 10 with compressor 11, can be configured as a compact exchangeable unit and be accommodated preferably beneath the supporting surface 5 forming the bottom, i.e. in the base 2 of the show case. For this purpose, the supporting surface 5 can extend not quite as far as two oppositely situated side faces 3, the air 6 being sucked in from the interior 4 by the fan 9 through the consequently produced one slot and, after passing through the exchanger 8, the air 7 again passes through the second slot into the interior 4, if the air movement is not effected through special openings. It is however also conceivable to accommodate the described devices in an upper part which seals the show case at the top instead of the upper side face 16. It is also possible likewise to fit the mentioned devices in the region of a side part 3 which in this case is then not formed from glass, these devices requiring to be covered correspondingly for optical reasons.

The invention is not restricted only to this known type of production of cold but the required cold can also be produced in another manner, for example by using Peltier elements. The construction of the exchanger 8 can thereby also be changed if the latter together with the Peltier elements is fitted not beneath the supporting surface 5 but on one of the side faces 3. When using Peltier elements, by means of which electrical energy is converted directly into heat and/or cold, the possibility exists in addition of configuring the control device 14 in such a manner that the level of the voltage supplied to the Peltier elements is adjusted automatically as a function of the signals of the temperature sensors.

Hence the surface temperature of the exchanger 8 can be adjusted in a particularly precise manner, as a result of which the temperature of the air in the interior 4 can in addition be precisely adjusted within the framework of the smallest temperature fluctuations. The exchanger 8 can also be configured in such a manner that the quantity of air supplied to the latter or respectively discharged from the latter is adjustable. This regulating function also can be taken over by the control device 14 if the corresponding regulating device for the quantity of air is connected to the control device 14 and obtains its control signals in the described manner as a function of the signals of the sensors from the control device 14.

12 Reference number list 1 upper part 2 base 3 side faces 4 interior supporting surface 6 incoming air 7 outgoing air 8 exchanger 9 fan cooling device 11 compressor 12 first temperature sensor 13 second temperature sensor 14 control device third temperature sensor 16 upper side face

Claims

2. The method according to claim 1, whereby the air is guided constantly through the exchanger.
3. A device for implementing the method according to one of claims 1 or 2, wherein a first thermoswitch is fitted in the interior which produces a signal when a prescribed temperature is exceeded, a second thermoswitch is fitted on the exchanger which produces a signal when a prescribed temperature is fallen below, and both thermoswitches are connected directly or indirectly to a drive of the cooling device.
4. The device according to claim 3, wherein a cold accumulator is provided between the exchanger and the cooling device. The device according claim 3, wherein the cooling device is itself configured as a cold accumulator.
6. The device according to one of claims 3 to wherein one temperature sensor respectively is present instead of each of the first and second thermoswitch and both temperature sensors are connected to an electronic control device, the drive of the cooling device being effected as a function of signals of the control device. AH21(8728031) PRW
7. The device according to any one of claims 3 to 6, wherein the air is moved Sthrough the exchanger by means of an electromotor operated fan. O 8. The device according to any one of claims 3 to 7, wherein the drive of the fan is ID 5 effected as a function of signals of the control device.
9. The device according to any one of claims 3 to 8, wherein a third temperature 00 sensor is connected to the control device, said sensor being located outside the show case. 00 r 10 10. The device according to any one of claims 3 to 9, wherein the exchanger and cooling device are accommodated beneath the supporting surface forming the bottom of the interior, the supporting surface extending at least on two oppositely situated sides not quite as far as the side faces.
11. The device according to any one of claims 3 to 10, wherein the quantity of air supplied to the exchanger and or discharged from the latter is adjustable.
12. The device according to any one of claims 3 to 11, wherein the exchanger is thermally insulated on its outside.
13. The device according to any one of claims 3 to 11, wherein the exchanger is subjected on its outside to an air stream, preferably to outgoing air.
14. The device according to any one of claims 3 to 13, wherein one or more dew point sensors are connected to the control device. The device according to claim 6, including two of said control devices.
16. The device according to claim 3, wherein the air guided through the exchanger is heatable if required by suitable means.
17. The device according to claim 10, wherein the exchanger, the fan, the cooling device and the drive form a complete unit and this unit is exchangeable. AH21(872803_1) PRW
18. A method for air-conditioning a show case, said method being substantially as O hereinbefore described with reference to the accompanying drawings. O 19. A device substantially as hereinbefore described with reference to the N 5 accompanying drawings. Dated 16 October, 2007 0o Glasbau Hahn GmbH Co. KG 00 cN Patent Attorneys for the Applicant/Nominated Person C SPRUSON FERGUSON A1121(8728031) PRW