Patent Publication Number: US-2012034861-A1

Title: Apparatus and method for cooling housed spaces

Description:
The invention relates to a cooling system for housed spaces, in particular telecommunication devices equipped with electronics cabinets in the form of containers, and describes their operation. 
     Such containers, which are widely employed in the operation of transmitter masts for mobile communications technology, make use of air conditioning units for cooling purposes, which is not only energy-intensive, but also entails the emission of CO 2 . 
     EP 1 988 760 A1 describes a temperature control apparatus for a housed space outside a protective building, wherein electronic units are arranged. 
     By a systematic introduction of air, circulation and air outlets, it is intended to ensure an optimum operating temperature and relative humidity for the electronic units and to prevent moisture condensation. 
     Both in the region of the air inlets and the air outlets as well as inside the housed space, fans and a heating device are employed for this purpose, which can be actuated via a control device as a function of the determined temperatures. 
     The container described in WO 2005/034599 A1 for electronic components releasing heat is used in telecommunications installations. The container is divided into an inner and an outer housed space, wherein into the space therebetween air can stream in from the outside and out of it to the outside via vents. The electronic components are located inside the inner space, which is provided with an air conditioning unit. A second air conditioning unit is arranged in the partition wall between the inner and the outer housed space. 
     Aside from air conditioning units, an apparatus for cooling housed spaces in known from DE 20 2008 016 601 U1, consisting of a housing which is connected to the housed space via a supply air duct to and an exhaust air duct from the housed space and the housing is provided with at least one air intake duct for ambient air and with at least one air exit duct into the ambient air, wherein the air intake duct(s) into the housing and the supply air duct to the housed space are connected to each other with a fan being interposed, and the exhaust air duct from the housed space is connected to the air exit duct(s) from the housing, and an air filter is arranged at least in the air intake duct into the housing. 
     Preferably the connection of the exhaust air duct from the housed space to the air duct(s) from the housing is also realized with a fan being interposed. 
     A disadvantage of this solution is that the air exchange for cooling purposes is achieved exclusively via electrical fans. 
     Furthermore, rotor ventilators for space ventilation are known. Such a hybrid turbine is described in EP 1 360 442 B1 and is known in the market under the trademark ecopower (registered trademark of the Australian company Edmonds). It is a lamellar roof ventilator. 
     The object of the invention is to propose, in particular for autonomously installed containers, both an alternative solution to air conditioning units and a combined solution with existing cooling devices, wherein the energy consumption of the device is to be reduced to a minimum, among other things by employing the hybrid turbines mentioned above. 
     The object is achieved with the features of apparatus claim  1  and method claim  6 ; advantageous realizations are the subject of the subclaims. 
     The apparatus of the invention for cooling housed spaces, in particular telecommunications installations which are arranged in containers, provides a closable supply air duct for ambient air into the container, a closable exhaust air duct from the container, a fan arranged at the end of the exhaust air duct of the container, and a control device for the fan operating as a function of the climate, wherein the fan arranged outside the container can be driven by wind and by an electric motor, and via the control device the electric motor drive of the fan can be activated and deactivated as a function of preset input quantities and the climate parameters inside the container and opening, closing and/or adjustment of the supply air and exhaust air dampers of the supply and exhaust air ducts is effected, wherein aside from the climate parameters, at least the fan performance or fan speed which can be achieved with the existing wind load are available to the control device as input quantities. 
     Preferably the fan is a hybrid turbine, wherein the wind turbine itself operates as a centrifugal electric motor driven impeller. 
     In a further realization it is provided that the control device is connected, in terms of controls, to an autonomously operating air conditioning unit of the container, such that the air conditioning unit can be connected or disconnected. 
     Furthermore, the realization of the apparatus provides that the control device can be supplied with measurement data of the external temperature via an input device. 
     To avoid dust and insects from entering the container, it is further provided that an air filter is arranged at least in the supply air duct. 
     The proposed method of the invention for cooling the interior space of a container containing heat emitting electronic components, the container having a supply air duct for ambient air with an adjustable and closable supply air damper, an exhaust air duct into the ambient air with an adjustable and closable exhaust air damper, a fan arranged at the end of the exhaust air duct outside the container which can be driven by wind and by an electric motor, a control circuit for the electric motor drive of the fan and for adjusting the supply and exhaust air dampers, as well as at least one input device for the control circuit, provides that the control device is activated by predetermined control commands and/or by a setpoint/actual comparison of measured and preset climate quantities inside the container, the control device connects or disconnects the electric motor fan drive as a function of the setpoint/actual comparison of the climate quantities and the further input quantity on the fan performance or fan speed which can be achieved with the existing wind load, and adjusts the supply and exhaust air dampers. 
     The fan, in particular in the form of a hybrid turbine, is thus driven by the wind with the supply and exhaust air damper in the open position. The container is cooled by the air streaming through it without any supply of energy. 
     If at least one preset climate parameter inside the container, preferably an internal temperature, is exceeded, the motor fan drive is connected, such that the throughput of cooling air is maintained or increased even in the case of a potentially decreasing wind driving force. 
     If subsequently a preset climate parameter inside the container, preferably a preset internal temperature, is further exceeded despite the electric motor drive of the fan being connected, an alarm signal is emitted by the control device. 
     If the container is also provided with an air conditioning unit which has been switched off until this point, it can be connected if at least one preset climate parameter inside the container, preferably a preset internal temperature, is exceeded, wherein the motor fan drive which has been activated until this point is switched off and the supply and exhaust air dampers are closed. Cooling is then achieved exclusively via the existing air conditioning unit. 
     Analogously, if the internal temperature or another climate parameter decreases, the air conditioning unit is disconnected, the electric motor drive is switched on and the supply and exhaust air dampers are opened, and the electric motor operation is switched off when the control device has calculated from the input data the most favorable cooling variant with regard to energy efficiency. 
     Advantageously the measured external temperature outside the container is fed to the control device as a further input quantity. 
     Furthermore, the proposed apparatus enables that, if at least one climate parameter inside the container, preferably an internal temperature, falls below a preset value, first the supply air damper is closed, and if the temperature decreases further, also the exhaust air damper is closed, or both dampers are closed at the same time. A case like this indicates a malfunction, such that, if a climate parameter inside the container, preferably an internal temperature, falls below a preset value, an alarm signal is also emitted by the control device. 
     The alarm can be triggered in the known manner via an exterior display and/or a signal transmission, also via radio, to a control station. 
    
    
     
       The apparatus will now be described with reference to the drawings in which 
         FIG. 1  shows the container to be cooled in a side view A, and 
         FIG. 2  shows the container to be cooled in a side view B. 
     
    
    
     In  FIGS. 1 and 2  the apparatus for cooling telecommunications installations  8  which are arranged in containers  9  is illustrated. The container  9  is provided with a closable supply air duct  10  for ambient air into the container  9 , a closable exhaust air duct  7  from the container  9 , a fan  6 , in the form of a hybrid turbine which can be driven by wind and additionally an electric motor, arranged at the end of the exhaust air duct  7  outside the container  9 . The container  9  further contains a control device  4 , via which the electric motor drive of the fan  6  can be activated or deactivated as a function of preset input quantities and the climate parameters inside the container  9 , and via which opening, closing and/or adjustment of the supply air and exhaust air dampers  3 ,  5  of the supply and exhaust air ducts  7 ,  10  is effected. Aside from the climate parameters, at least the fan performance or fan speed which can be achieved with the existing wind load are available to the control device  4  as input quantities. 
     If an air conditioning unit  11  is present which can be operated autonomously, this can be incorporated into the energy-efficient cooling process by means of the hybrid turbine by connecting the control device  4 , in terms of controls, to the air conditioning unit  11  of the container  9 , such that the air conditioning unit can be connected or disconnected and in connection with this the conditions are set which are necessary for the operation of the air conditioning unit in the container  9 . 
     The control device  4  can be further supplied at least with measurement data of the external temperature via an input device. 
     It is further shown that an air filter  2  is arranged at least in the supply air duct  10 . 
     On putting the electronics  8  of the container  9  into operation, the electronic components start to emit heat, which is indicated by a temperature increase in the container  9 , measured by the sensor  12 . 
     The control device  4  registers this temperature increase (&gt;15° C.) and opens the supply and exhaust air dampers  3  and  5 . As a consequence of being driven by wind, the fan  6 , realized as a hybrid turbine, provides for a cooling air flow from the ambient air for cooling the components  8  (&lt;23° C.). If the control device signals that no wind is present for driving the fan or in the case of a further temperature increase (&gt;23° C.) due to insufficient cooling, the control device  4  connects the electric motor drive of the fan  6  or switches it on. The speed can be controllable. 
     If the cooling turns out to be insufficient—e.g. due to external temperatures being too high—the control device disconnects the electric motor drive of the fan  6  at temperatures around 30° C., closes the supply and exhaust air dampers  3  and  5  and activates the air conditioning unit  11 , which is now responsible for cooling entirely on its own. If no air conditioning unit is present or if the temperature keeps rising, an alarm is signaled. 
     Of course it is also possible to calculate the anticipated temperature profile taking into account the operational data and measured environmental data and to emit an alarm signal at an earlier time if a hazard has been calculated. This is usually done via radio to a main station. 
     If decreasing internal temperatures in the container  9  are registered, this process takes place in reverse order. 
     Temperature values below a preset low value should also result in triggering an alarm signal, since this is an indication of a potential operational malfunction. 
     Of course it is also possible to monitor the performance of the individual steps of the method by corresponding sensors, e.g. the closed state of the supply and exhaust air dampers  3  and  5 . Also here, any detected faults can result in an alarm being triggered. 
     Calculations made by the applicant have shown that with the proposed unit, each year 1,500 KW/h per unit are saved and a reduction in CO 2  emissions of 960 kg per unit is achieved compared to the predominantly existing air conditioning cooling. An enormous technological progress, considering the approximately 8,000 stations existing in Germany. 
     LIST OF REFERENCE NUMERALS 
     
         
           1  Protective grille, in particular weather protection 
           2  Filter 
           3  Supply air damper with control unit 
           4  Control device 
           5  Exhaust air damper with control unit 
           6  Fan 
           7  Exhaust air duct 
           8  Electronics 
           9  Container 
           10  Supply air duct 
           11  Air conditioning unit 
           12  Sensor