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(11) Patent Number: KE 301 (45) Date of grant: 12/02/2009
11E111
Kenya Industrial Property Institute
(19) Kenya Industrial Property Institute.
 
(12) PATENT
(51) Int.CI.7: H 05K 7/20
(21)Application    KE/P/ 2004/ 000365    (84) WO No. WO 2005/034599
Number:    04/04/2005
(22) Filing Date:    14/06/2004
(31)Priority Number: 0302628-3    (32) Date: 06/10/2003 (33) Country: SE
(73)    Owner(s): MKU CYPRUS LIMITED of CENTENIAL BUILDING, 7th FLOOR P.0 1066, Nicosia ,Cyprus.
(72) Inventor(s)    ERIKSSON, ULF, JORGEN
(74)    Agent/address for correspondence: Waruinge & Waruinge Advocates

(54) Title: (57) Abstract:    A PROTECTIVE BOX-LIKE CABINET WITH COOLING ARRANGEMENTS A protective shelter or cabinet related arrangement, wherein a first cabinet (10) is
adapted to enclose electronic equipment (la, lb, 1c) which develops heat inside said first cabinet during operation, and a first air conditioning unit (11), adapted to regulate the temperature inside said first cabinet (10) and a standby battery assembly (2), wherein said standby battery assembly is enclosed in a further, a second, cabinet (20), whereby said further cabinet (20) is allotted a further, a second, air conditioning unit (21), each unit (11, 21) being adapted to regulate and keep the temperature within its related cabinet at a pre-selected level, and wherein said second air conditioning unit (21) is a thermo-electrically operated unit disposed with its cooling section (21a) facing towards said second cabinet (20) and with its heating section (21b) facing towards said first cabinet (10).
 
1
A protective box-like cabinet with cooling arrangements
5 FIELD OF INVENTION.
The present invention pertains generally to an arrangement relating to a protective box-like shelter or cabinet and more particularly to a temperature regulating arran-gement, where said box-like shelter as a structure or cabinet is adapted inter Oa, to enclose electronic equipment that generates heat when in operation.
10
In order to regulate the temperature of the interior of said shelter or cabinet towards a predetermined or pre-set value, such as a constant value, said cabinet encloses or is connected to one or more temperature regulating means, in the following de¬signated as a first air conditioning unit.
15
Said first air conditioning unit is normally adapted to extract heat from the interior of the cabinet, in the following designated as a first cabinet or housing.
Moreover the enclosed electronic equipment is, for safety reasons, connectable to 20 one or more standby battery assemblies, in the following illustrated as a first battery assembly.
The standby battery assembly is enclosed in a further, second cabinet or box which is much smaller than the first cabinet enclosing said electronic equipment and which
25 includes a further temperature regulating means, in the following designated as a second air conditioning unit, adapted to regulate and keep the temperature within said second cabinet at a predetermined value or per-set value, such as a constant value or level.
30 The temperature regulating arrangement, related to the present invention, is adap-
ted for use within a first cabinet, in a form and shape adapted to enclose one or more telephone system related equipments, particularly a telephone station related to a mobile telecommunications system, such as GSM- and UMTS-systems.
 
RELATED PRIOR ART
In the case of said first cabinet, especially in regard of a telephone station, where the enclosed electronic equipment generates more or less time-related heat, where¬by the heat generated is dependent on operation intensity, it is known to use diffe-
5 rent temperature regulating means and/or arrangements and/or first air conditioning units to regulate the prevailing temperature towards a chosen and constant value, this value being, in the following description, designated as a high temperature va¬lue, and is regulated towards a constant value, falling within the temperature range of say 30 to 40°C.
10
Moreover the used temperature regulating means, an arrangement constructed to this end and/or an air conditioning unit are each adapted for regulating a momentary temperature within a stipulated temperature span, required for a longer life function of the electronic equipment.
15
However a required standby battery assembly is usually enclosed in a small second cabinet or box-like structure, arranged within and covered by said first cabinet and thus influenced indirectly by the regulated high temperature value within the cabinet.
20 Used lead-acid type of standby batteries should have, within said second cabinet or box, an environment whose prevailing temperature has been regulated towards a predetermined value, a constant value, this value being designated as a low tempe¬rature value.
25 Consequently a temperature regulating arrangement, related to each of said two ca¬binets, must individually regulate the temperatures within the two different environ¬ments towards two different temperature values and thus considering different crite-ria, one set of criteria being valid for the electronic equipment within said first cabi¬net on the one hand and another set of criteria being valid for the lead-acid batteries
30 within said second cabinet on the other hand.
With regard to the basic concept of the present invention, there is known, from Pa¬tent Publication US-A1-2003/0094 263, a method and an apparatus related to a first cabinet or housing for electronic equipment, which are intended to extend the useful
 
life of a lead-acid type standby battery assembly by applying a "conductive" cooling function directly towards the bottom surfaces of the batteries, in order to maintain
the batteries and said second cabinet at a constant temperature, of about 25°C, regardless of the ambient temperature surrounding the battery assembly and said
5 second cabinet or box.
In this publication figure 1 illustrates schematically an outdoor electronic equipment including cabinet, denoted generally by reference numeral (10), which is designed to enclose active communications equipment, such as banks of printed circuit boards
10    or the like.
The cabinet is divided into an upper equipment-related or enclosing chamber (12) and a lower battery-related or enclosing chamber (14).
15 A bank of back-up batteries (16), typically of a lead-acid type, is thus disposed in a separate battery chamber (14).
A flat cold plate (20) included in a temperature regulating means or air conditioning unit is here disposed beneath the batteries (16), and is in a direct contact therewith.
The cold plate (20), sometimes also referred to as an evaporator, is connected thro¬ugh suitable conduits (22 and 24) to a compressor (30), which is designed to circu¬late a refrigerant through the cold plate (20), to achieve a predetermined temperatu¬re within said second, and separate battery, chamber.
Located beneath said cold plate (20) is a heating pad (32). Once again, there is di¬rect contact between the heating pad and the cold plate. Direct contact implies that heat transfer will occur through conduction and not through convection.
30 That is to say, a cooled cold plate will engender heat flow from the batteries to the cold plate under warm ambient conditions. The same is true under cold ambient conditions. Heat from the heating pad will be transferred by conduction to the cold pate and in turn will be transferred to the batteries by conduction.
 
The main objective here is to efficiently and effectively maintain the batteries at a constant temperature and regulate the instant temperature within set values, such as 25°C, plus or minus about 2°C. This will greatly prolong battery life in a reliable and relatively inexpensive manner.
5
An insulation pad (34) is located beneath the heating pad and minimizes heat trans-
fer to a concrete pad (35), which is typically used to mount equipment cabinets. The
insulation pad may be made of high temperature plastic, one eighth of an inch thick.
10 The cabinet also encloses a heat exchanger (36) in the equipment or first chamber (12). The heat exchanger (36) sucks in ambient air (40) through a set of louvers (44) related to the batteries-housing cabinet, through the agency of a fan (42). The used air is then exhausted through a second opening (46), back to the ambient environ-ment.
15
The air heated by the equipment in chamber (12) is moved through the heat ex¬changer (36) by a second fan (50). The air enters the heat exchanger (36) through an opening (52) and exits back into the equipment chamber (12) through another opening (54).
20
The air from the equipment chamber (12) and the ambient air never mix even tho¬ugh a heat exchange occurs.
Moreover, the equipment chamber (12) is weather sealed so that air, dust, water 25 and the like is kept away form the equipment, except when the equipment is servi¬ced.
The compressor dissipates that through an opening (56) in the cabinet.
30 This arrangement uses an air conditioning unit with a compressor, whereby the heat generated by this unit is directly transported to the ambient air.
The air intake is arranged to pass said second cabinet and thus the temperature re¬gulation is dependent on the ambient air temperature.
 
5
Consequently it is well known that a normal radio base station (RBS) or electronic enclosure or cabinet (shelter) that is seen along the roads with a mast develops a large amount of heat load from its equipment (GSM- or UMTS-system related equip-
5 ment).
A normal yearly average energy consumption required to cool down the interior of the cabinet, is calculated, under realistic conditions and criteria, up to 26000 kWh/ year.
10
In some applications ambient filtrated air is used to cool down the cabinet (free coo¬ling). In these cases there is a risk that contaminated air will pass inside the cabinet, however in this application energy consumption is very low.
15 Telecom standard designated ETSI (European Telecom Standard) for example has one condition stating a max 0,5°C temperature change per minute, for the internal temperature of said first cabinet adapted for a RBS-station.
Free cooling with a heat exchanger that does not mix indoor air with ambient air
20 without the use of a filter is favourable and can be temperature controlled with a fan, driven by 48 VDC.
The following Patent Publications US-A-5 697 840 and US-A-6 164 369 also form parts of relevant prior art documents.
25
Normally an RBS-station, enclosed in a first cabinet, has been cooled down to 25°C, with different kind of air-conditioners, for achieving human comfort cooling, and the temperature thus chosen is not especially designed for the operation of the installed electronic equipment, which requires not only a higher temperature but also requires
30 a temperature swing of less than 0,5°C temperature changes per minute.
The traditional choice of 25°C in the first cabinet or electronic enclosure is due to the stored standby battery assembly, which is very sensitive to temperature changes.
 
6
Test results tell us that, when a battery temperature is beneath 20°C the voltage will increase so as to keep the batteries unharmed or vice versa.
Therefore thermal runaway can occur and standby batteries have to be re-charged 5 quite frequently.
Some manufactures of lead-acid type batteries recommend a constant temperature of 20°C for optimal lifetime and expects a very small temperature swing.
10 Standby batteries are used when there is a power failure to the site, so that the RBS-station can operate in an emergency state for e.g. 4 hours.
Normal operation of an RBS-station and its cabinet is in fact crucial, when it comes to emergency situations, so that people, fire departments, police, ambulance servi¬15 ces etc. can be contacted over S.O.S.
SUMMARY OF THE INVENTION
TECHNICAL PROBLEMS
When taking into consideration the technical deliberations that a person skilled in
20 this particular art must make in order to provide a solution to one or more technical problems that he/she encounter, it will be seen that it is necessary initially to realise the measures and/or the sequence of measures that must be undertaken to this end on the one hand, and on the other hand to realise which means is/are required to solve one or more of said problems. On this basis, it will be evident that the techni-
25 cal problems listed below are highly relevant to the development of the present in-vention.
When considering the prior art mentioned above it must be seen that a technical problem is one of evaluating the consequences of comprehending and realising the
30 advantages of taking and/or suggesting constructive steps within a shelter or first cabinet, adapted to enclose an electronic equipment that develops heat in operation inside said first cabinet, and using a first air conditioning unit, adapted to regulate
the temperature inside said first cabinet and using a standby battery assembly, wherein said standby battery assembly is enclosed in a further or second cabinet,
 
and wherein said further or second cabinet is allotted a further or second air condi¬tioning unit, adapted to regulate and keep the temperature within said further or se¬cond cabinet at a constant level, and of providing an energy saving temperature re¬gulating arrangement in which said further or second air conditioning unit includes a
5 cooling section that faces towards said further or second cabinet and its enclosed standby battery assembly or assembles and also includes a heating section that fa-ces towards said first cabinet and its enclosed electronic equipment.
Another technical problem will be seen to reside in evaluating the consequences of
10 comprehending and realising the advantages afforded by and/or the suggestion of constructive steps to be taken in designing said first air conditioning unit to keep the temperature within said first cabinet at a pre-set constant high temperature level, such as 35°C or thereabout, while taking into account any heat generated by said heating section entering said first cabinet.
15
Another technical problem will be seen to reside in evaluating the consequences of comprehending and realising the advantages afforded by and/or the suggestion of constructive steps to be taken in arranging and especially designing said first air conditioning unit for a set of electronic equipments, with a maximized predetermined
20 swing, such as a temperature change of less than 0,5°C per minute.
Another technical problem will be seen to reside in evaluating the consequences of comprehending and realising the advantages afforded by and/or the suggestion of constructive steps to be taken in adapting said standby battery assembly to energi-
25        ze said first and second air conditioning units and said electronic equipment during
a pre-set time, following a power supply failure.
Another technical problem will be seen to reside in evaluating the consequences of comprehending and realising the advantages afforded by and/or the suggestion of
30 constructive steps to be taken in arranging for gases, such as issuing from a lead-acid battery assembly, to be ventilated out from the assembly cabinet to ambient outdoor air through a small pipe or hose.
 
Another technical problem will be seen to reside in evaluating the consequences of comprehending and realising the advantages afforded by and/or the suggestion of constructive steps to be taken in effecting said ventilation by activating a fan, cau¬sing an overpressure inside said further or second cabinet.
5
Another technical problem will be seen to reside in evaluating the consequences of comprehending and realising the advantages afforded by and/or the suggestion of constructive steps to be taken in providing said first cabinet with a double wall struc¬ture, where ambient air is caused to pass between said walls, either through con-
10 vection and/or through the medium of a fan.
Another technical problem will be seen to reside in evaluating the consequences of comprehending and realising the advantages afforded by and/or the suggestion of constructive steps to be taken in applying to the inner wall structure of said first ca-
15 binet a double sided and extruded heat-sink air to air heat exchange unit.
Another technical problem will be seen to reside in evaluating the consequences of comprehending and realising the advantages afforded by and/or the suggestion of constructive steps to be taken in locating said extruded heat sink exchange unit ad-
20 jacent the walls and/or ceiling of said structure, with one side so as to sense the am-
bient or outdoor condition and the other side so as to sense the indoor condition.
SOLUTION
This invention has as its starting point an arrangement related to a protective shelter
25 or first cabinet, adapted to enclose electronic equipment that develops heat during its operation, and a first air conditioning unit, adapted to regulate the temperature inside said first cabinet towards a first predetermined, such as constant, level, and
the use of a standby or back-up battery assembly or assemblies, wherein said standby battery assembly is enclosed in a further, a second, cabinet, whereby said
30 second cabinet is allotted a further, a second, air conditioning unit which is adapted to regulate the temperature inside said second cabinet towards a second predeter-mined, such as a constant, level and whereby said first level is chosen higher than said second level.
 
9
With the intention of solving one or more of the above mentioned technical problems the invention proposes an arrangement where said further or second air conditio¬ning unit is arranged with its cooling section facing towards the inner of said further or second cabinet and with its heating section facing towards the inner of said first cabinet.
Suggested additional features, related to the present invention, are that said first air conditioning unit is adapted to keep the temperature within said cabinet at a first predetermined value, such as a constant level, adapted to requirements stipulated
10 by the producer of the enclosed electronic equipment, such as a temperature level of 35°C or thereabouts.
Moreover said first air conditioning unit is arranged for and especially designed for a chosen electronic equipment or equipments, with a maximized predetermined tern-
15 perature variation or change per time unit, such as a temperature change of less than 0,5°C per minute.
Said standby battery assembly is dimensioned and adapted to fully energize said first and second air conditioning units and said electronic equipment or equipments 20 over a predetermined and pre-set time interval, in the event of a power failure.
Gases generated from lead-acid batteries within said assembly are ventilated out to ambient outdoor air through a small pipe or hose.
25 Said ventilation is achieved by operating a fan that creates an overpressure in the second cabinet.
Further, there is applied to said first cabinet a double sided, extruded heat-sink air-
to-air heat exchange unit, said extruded heat sink heat exchanger being located at
30 one or more walls and wall sections and/or at the ceiling and ceiling sections, with one side facing ambient shadow conditions and with the other side facing the indoor conditions within said first cabinet.
 
10
ADVANTAGES
The primary advantages that are afforded by and in association with an arrange¬ment, related to a shelter or cabinet (a first cabinet), adapted to enclose electronic equipment or equipments that develop heat inside said first cabinet during opera-
5 tion, and including a first air conditioning unit, which is adapted to regulate the tem-perature inside said first cabinet and a further smaller cabinet (a second cabinet) or box which is enclosed in said first cabinet and adapted to enclose a standby battery assembly and/or assemblies and a second air conditioning unit, adapted to regulate the temperature inside said second cabinet, are that heat generated by said second
10    air conditioning unit, related to said second cabinet, is directly transferred into said
first cabinet, as a heat supply, and the subsequent reduction in the total energy con¬sumption.
BRIEF DESCRIPTION OF THE DRAWINGS
15 An embodiment at present preferred and having features significant to the present invention will now be described with reference to the accompanying drawings, in which;
Figure 1 is a perspective and partly cut away view of a protective shelter or a first
20 cabinet, enclosing electronic equipment related to a GSM-system, and enclosing also a further or second, smaller, cabinet or box, housing a standby battery assemb¬ly and illustrates an arrangement related to the present invention.
Figure 2 is a first perspective view of an arrangement-related second air conditio¬25 ning unit and shows the part thereof facing towards said first cabinet enclosing said electronic equipment,
Figure 3 is another perspective view of said second air conditioning unit, according to figure 2, and shows the part thereof facing towards said further or second cabinet 30 or box enclosing said standby battery assembly,
Figure 4 shows a double sided extruded heat-sink or air-to-air heat exchange unit,
 
11
Figure 5 shows a cut-away section of said heat exchange unit illustrating three fins arranged to one side of a basic member,
Figure 6 shows a section of said heat exchanged first cabinet and
5
Figure 7 shows a simplified electric wiring diagram illustrating the cooperation of the means related to the present invention.
DETAILED DESCRIPTION OF A PROPOSED EMBODIMENT
10 It should initially be made clear that we have selected terms, expressions and spe-cial terminology in the following description of an embodiment suggested at the pre¬sent time that demonstrates the significant characteristics associated with the inven¬tion and that is described with reference to the figures shown in the attached dra¬wings, in order, primarily, to make clear the innovative concept of the invention.
15
It should, however, be taken into consideration that the expressions selected here are not to be seen as being limited to only the term selected and used here, but it is rather to be understood that each such selected term is to be interpreted such that it additionally covers all technical equivalents that act or function in the same manner,
20 or in essentially the same manner, in order to in this way achieve the same intention
and/or technical result, or essentially the same intention and/or technical result.
Figure 1 is a perspective view of a protective shelter or cabinet that accommodates a telephone station 1, wherein said cabinet includes a first cabinet structure 10,
25 which accommodates a telephone station 1 that is allotted or formed with selected electronic equipment or equipments la, lb and 1c, here illustrated as an electronic equipment required for a GSM mobile telecommunications system or any other system.
30 Said electronic equipment la, 1b, 1c generates heat during its operation and the heat intensity generated varies in time, more heat being generated at "busy hours".
This means that the generated heat will differ from time to time and thus the magni¬tude of the temperature in said first cabinet 10 will tend to vary as a function of time.
 
12
It is also to be noted that the ambient air, the wind and/or the temperature, also in¬direct affects the indoor temperature.
5 Some wall sections in figure 1 are cut away, so as to expose some of the interior of said station 1 and cabinet 10 and the construction of the wall sections.
A first air conditioning unit 11 (not shown but indicated) is adapted to regulate the temperature inside said cabinet 10 and said unit 11 is adapted to regulate the indoor 10 temperature towards a constant and predetermined pre-set value.
This first air conditioning unit 11 is constructed as a compressor driven air conditio¬ning unit and is adapted to have a capacity sufficient for its purpose as described above.
15
This pre-set value is recommended by the producer or manufacturer of the electro¬nic equipment la, 1b, lc and is in this exemplified embodiment set to 35°C. The maximum temperature variation per time unit is also set by the producer, and the used first air condition unit 11 is dimensioned and adapted to fulfil these conditions
20    and criteria.
A further, small or second cabinet or box 20 is adapted to enclose a standby battery assembly or assemblies 2.
25 The standby battery assembly 2 is here shown fully enclosed by the second cabinet or box 20, which is formed from heat insulating wall sections and allotted a further or a second air conditioning unit 21, adapted to regulate and to keep the temperature values within said second cabinet 20 at a constant level.
30 The second air conditioning unit 21 is primarily adapted to regulate the interior tem¬perature of the second cabinet towards a predetermined pre-set value.
 
13
This value is strongly recommended by the producer or manufacturer of the used batteries, such as lead-acid batteries 2a, and in this exemplified embodiment is said value set to 20°C.
5 It will be obvious that the two air conditioning units 11 and 21 have mutually different dimensions and that the unit 11 is dimensioned for a higher capacity than the unit 21.
As already mentioned, the first air conditioning unit 11 is constructed as a compres-
10 sor driven air conditioning unit, with a capacity adapted to the environment within said first cabinet 10, and the second air conditioning unit 21 is constructed as a thermoelectric cooling/heating unit, with a capacity adapted to the environment within said second cabinet 20.
15 Thus the capacity allotted to the first air conditioning unit 11 is chosen much higher than the capacity allotted to the second air conditioning unit 21, these units being of different types.
It has been mentioned that the second cabinet 20 is wholly or partly enclosed within 20 said first cabinet 10. However if falls within the concept of the present invention to arrange said second cabinet 20 adjacent to or close to said first cabinet 10.
Although the use of two different kinds of air conditioning units 11 and 21 is sug¬gested with regard to the inventive arrangement, the following description will con-
25 centrate towards the second air conditioning unit 21, shown in two different perspec¬tive views in figures 2 and 3.
This further or second air conditioning unit 21 is disposed with its cooling section 21a (figure 3) facing towards the further or second cabinet 20 and is ceiling related,
30 and with its heating section 21b (figure 2) facing towards the first cabinet 10 and spaced from the floor.
This arrangement of the cooling section 21a causes cooled air to sink over the bat¬teries and thus cause an air to circulate within the cabinet 20, while the heating sec-
 
14
tion 21b causes heated air to rise over the batteries and thus result in the circulation of air in said first cabinet 10.
As shown in Figure 6, the second air conditioning unit 21 is mounted on an upper
5 wall section or ceiling section of the second cabinet or box 20, with its cooling sec¬tion 21 a fully exposed to the interior of a smaller second cabinet 20 and its heating section 21b fully exposed to the interior of the larger first cabinet 10.
The inner space of said second cabinet 20 is only somewhat larger than the volu¬10 metric space and the confines of the batteries and said cooling section 21 a.
Thus, this second air conditioning unit 21 will add, a small more or less constant, amount of heat to the interior of said first cabinet 10.
15 The first air conditioning unit ills dimensioned and adapted to keep the tempera¬ture within said first cabinet 10 at a constant level, say 35°C, and is further dimen-sioned for regulating the temperature within a pre-set maximum temperature chan¬ge, here illustrated as 0,5°C per minute, taking into account the heat transferred to cabinet 10 from the second air conditioning unit 21.
20
Moreover said standby battery assembly 2 is adapted to energize, at full capacity, said first and/or second air conditioning unit 11, 21 and said electronic equipment 1 a, lb, lc in the event of a power supply failure and the capacity of the batteries must be chosen for operating the station 1 over a predetermined time duration.
During this predetermined time period, there may be used said electronic circuit, which during a short time duration is forced to accepts a higher temperature in the first cabinet 10, say 45°C, wherein said electronic circuit may function to disconnect the first air conditioning unit 11 at a temperature below a maximum value.
Gases from the batteries 2a in said assembly 2 are ventilated out from the second cabinet 20 to ambient outdoor air through a small pipe or hose 2b; ventilation being effected with the aid of a fan 21c that creates an overpressure in said second cabi¬net.
 
15
A small pipe or hose 2c is arranged adjacent the fan 21c and serves as an ambient outdoor air inlet.
5 As will be seen from figure 6, the first cabinet 10 is of a double-wall construction or the vertical walls are formed as a double jacketed chimney shelter causing the air inside said double-wall construction to represent the ambient shadow temperature, where ambient outdoor air is drawn by convection between the walls so as to gene¬rate a "shadow" related temperature with regard to the inner wall section, which is
10 covered with an inner heat insulating layer.
Moreover, there is applied to all or selected inner wall sections of said first cabinet 10 a double sided, extruded heat-sink and air-to air-heat exchange unit 30, as illust¬rated in figures 4 and 5.
15
This extruded heat-sink air-to-air exchange unit 30 is located at the walls and/or cei¬ling of said first cabinet 10, with one side of the unit 30 facing the ambient conditions between the parallel wall sections and with the other side thereof facing the interior conditions, as illustrated in figure 6.
20
Thus the present invention has provided totally innovative technology directed to¬wards the telecommunications sector and enabling energy savings to be enhanced through the agency of mutually separated temperature zones in an electronic enclo-sure 10, the actual life span to be extended and the surety that every component in
25 an electronic shelter or cabinet 10 will maximize its performance.
A special cooling/heating thermo electric principle for the batteries 2 has been deve¬loped, combining a separate battery compartment or cabinet 20 from power racks 1a, 1 b, 1c. The battery cooling/heating unit 21 is constantly powered by 48 VDC.
30
Batteries 2a are cooled or heated to a fixed temperature of 20°C. This will optimise the performance and the life span of the batteries. Gases emitted from batteries are ventilated out to the ambient air through the medium of a small outlet tube 2c and a small inlet tube 2c and by the fan 21c that pressurises the cabinet 20.
 
16
By insulating the batteries 2a from the rest of the equipment (micro climate) this al¬lows the manufactures and the operators of telecom equipment to change the spe¬cification to a higher slowly floating room temperature (macro climate).
Operating temperature between min 25 and max 40°C for the electronics in RBS¬equipment is chosen during normal operation.
In emergency situations higher temperature values are allowed e.g. 45° - 55°C.
The interrelation between the micro- and macro-climate zones have an extreme impact in energy savings and service costs.
The double wall construction of the cabinet 10, as shown in figures 1 and 6, is an 15 example of how to circulate ambient air between walls and a ceiling to avoid a sun-radiation temperature rise from the outside.
The double-sided heat sinks 30, placed in an auto-convection air gap, will extend used surface area and heat flux out to ambient air or an outer environment.
20
Further, the present invention is especially adapted for use when upgrading existing sites with power racks with battery cooler/heater units and slowly float the room tem¬perature between e.g. 30 — 35°C.
25 Large amounts of energy can be saved and the life span of existing equipment can be extended, and more RBS- quipment can be fitted in operating shelters or cabi¬nets without changing the cooling system in use.
Features related to the present invention;
30
Low service visits    No moving parts except from the 48 VDC fans.
No filter is used;    By floating the indoor temperature between e.g.
25-50°C filters do not need to be switched that frequently.
 
17
Long life span:    10 years for batteries. Fans with 100.000 hours life
span.
Low investment    Positive investment before energy savings has been
calculated.
5 High energy saving:    EPS geographically optimised k-value and micro- and
macro-climate zones.
Thus the invention combines an interrelation between a micro-climate, in the battery compartment or cabinet 20, and a macro-climate in the shelter or electronic enclo-
10 sure or cabinet 10, with a selection of different cabinet temperatures, but it also
combines special shelter or cabinet solutions or a normal shelter in the shade.
These two climate zones and new shelter or cabinet specifications give very large advantages for free cooling worldwide.
15
Figure 4 shows a double sided and extruded heat sink and air-to-air heat exchange unit and figure 5 shows a section of said heat exchange unit.
This unit 40 exposes a main body 41 and one side of said body is formed with a row 20 of first fins 42 and the other side of said body is formed with a row of second fins 43.
The unit 40 or a number of such units is/are disposed in a wall section 10a or wall sections 10a, 10b in the first cabinet 10 and first fins 42 facing outwards and second fins 43 facing inwards.
The fins 42a, 42b and 42c in figure 5 are mutually parallel and define there between air-flow channels, via which heat is transferred from one side 42 to the other 43 or vice versa depending upon the actual temperatures prevailing on each side of the wall sections 10a resp. 10b.
Figure 6 is a sectional view of said first cabinet 10 (and also of said second cabinet or box 20) from which it will be seen that the walls sections 10a, 10b and the ceiling 10c are covered by outer wall sections 60a, 60b and 60c, leaving between said wall sections 10a, 60a; 10b, 60b vertically extending air flow channels.
 
18
Ambient air is introduced through these channels via a slot 61 in the bottom section of said wall section 60a and is returned to the ambient air through an upper slot 62, by convection.
5
The same applies to the wall section 60b, using to this end slots 61 a and 62a and other wall sections (such as slot 61b in figure 1).
Figure 7 shows a simplified electric wiring diagram, in which an alternating power 10 supply is fed to a set of rectifiers 71 through wires 70.
The batteries 2a in the standby battery assembly 2 are charged via a wire 71a si¬multaneously and the power supply 48 VDC is fed through a wire 71b to the first 11 and the second 21 air conditioning units and to the electronic equipment la, lb, 1c.
15
Temperature sensors or temperature sensing and control circuits 11 a and 21a are arranged to activate each related unit 11, 21 to regulate the temperature towards a pre-set value, say 35°C and 20°C.
20 In response to a power supply failure the rectifying circuit 71' starts to feed power 48 VDC to a wire 71c and the first 11, the second 21 air conditioning units, and the electronic equipment 1a, lb, 1c are powered via said batteries only.
In this emergency situation, where the batteries 2a are only used to power the sta-
25 tion 1, there is shown in figure 7 the use of an additional temperature sensing and, control circuit 11 b, this circuit 11 b is adapted to detect the temperature of the first cabinet 10 and to raise the temperature towards a higher level, such as to a tem¬perature of 45°C.
30    Such an additional circuit may be connected to the air conditioning unit 21. It will be
noted, however, that the capacity of the batteries used is lower at higher temperatu¬res.
 
19
With reference to Figure 6 it is further suggested that if the ambient air has a high temperature, say above 40°C, the ventilation effect is necessary in order to maintain the ambient shadow temperature.
5 It will be understood that the invention is not restricted to the aforedescribed and illustrated exemplifying embodiment thereof and that modifications can be made within the scope of the inventive concept, as defined in the following claims.
 
20
CLAIMS
1.    A protective shelter or cabinet related arrangement, where a first cabinet (10) is adapted to enclose electronic equipment or equipments (la, lb, lc) which develops heat inside said first cabinet at least during operation, and a first air conditioning unit
5 (11), adapted to regulate the temperature inside said first cabinet (10) and a standby battery assembly (2), wherein said standby battery assembly is enclosed in a furt¬her, a second, cabinet (20), whereby said further cabinet (20) is allotted a further, a second, air conditioning unit (21), each unit being adapted to regulate and keep the temperature within its related cabinet at a pre-selected level, characterized in that
10 said further or second air conditioning unit (21) is disposed with its cooling section
(21a) facing towards said second cabinet (20) and with its heating section (21b) facing towards said first cabinet (10).
2.    An arrangement according to claim 1, characterized in that said first air condi¬15 tioning unit (11) is adapted to keep the temperature within said cabinet (10) at a high Predetermined temperature, such as a constant level, say 35°C.
3.    An arrangement according to claim 2, characterized in that said first air condi¬tioning unit (11) is intended and especially designed for electronic equipment (la,
20 lb, 1c), with a predetermined, maximized, temperature difference per time unit, such as a temperature swing of less than 0,5°C per minute.
4.    An arrangement according to claim 1, characterized in that said standby battery assembly (2) is adapted to energize, via its batteries, said first and said 25 second air conditioning unit and said electronic equipment during a power failure.
5.    An arrangement according to claim 1, characterized in that gases from said batteries within said assembly (2) are ventilated out from said second cabinet (20) to ambient outdoor air through a small pipe or hose (2b).
30
6.    An arrangement according to claim 5, characterized in that said ventilation is caused by a fan (21 c) that creates an overpressure inside said second cabinet (20).
 
21
7.    An arrangement according to claim 1, characterized in that to said first cabinet (10) includes a double sided, extruded heat-sink and air to air heat exchange unit.
8.    An arrangement according to claim 7, characterized in that said extruded heat 5 sink exchange unit is located at the walls and/or ceiling with one side facing ambient conditions and one side facing indoor conditions.
9.    An arrangement according to claim 1, characterized in that walls related to said first cabinet (10) form a double jacketed chimney shelter.
10
10.    An arrangement according to claim 1, characterized in that said first air con¬ditioning unit (11) is in the form of a compressor-operated air conditioning unit.
11.    An arrangement according to claim 1 or 10, characterized in that said second 15    air conditioning unit (21) is in the form of a thermo-electric operated air conditioning
unit

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