FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
AN ENCLOSED SPACE CABINET CONFIGURED FOR HIGH SENSIBLE HEAT LOAD APPLICATION;
BLUE STAR LIMITED, A COMPANY INCORPORATED UNDER COMPANIES ACT 1956, WHOSE ADDRESS IS KASTURI BUILDINGS, MOHAN T. APVANI CHOWK, JAMSHETJI TATA ROAD, MUMBAI - 400 020, MAHARASHTRA, INDIA
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF INVENTION
The present invention generally relates to enclosed space cabinets configured for continuous high sensible heat load application.
BACKGROUND OF THE INVENTION
System/Units for providing cooling to outdoor shelter housings have been known in the art. The application of cooling systems is known in telecommunication shelters as well. Telecommunication (telecom) shelters are typically constructed as an outdoor facility in either modular insulated polyurethane foam (PUF) panels or equivalent structure for housing an electrical and electronic system. These shelters are usually attached with an air-conditioning unit for providing cooling for the electrical and electronic systems therein. A conventional air conditioning system associated with the shelter is typically powered from standard Alternating Current (AC) power supply and hence only operates and provides cooling as long as there is AC power available.
Cooling for outdoor telecom shelters is critical for proper operation of the electrical and electronic systems housed therein. Typically the electrical and electronic systems for telecom equipment installed in the shelters have an over-temperature shutdown monitor built into the equipment. Thus, the time that the

telecom systems can operate is not limited by the battery life, but is limited by the time that the system can operate before it reaches the over-temperature shutdown threshold when the A/C system for providing cooling to the shelter is no longer functioning. This time depends on the external ambient conditions but is typically quite short (approx 20 minutes to 1 hour) for conventional telecom shelter. One potential solution is to use a DC to AC inverter in the event of a standard AC power failure. However, this is considered to be not practical, because it would require a very large battery storage capability. Generally a backup generator is employed for this purpose as a standard solution.
Traditionally, a cabinet with air conditioning system for continuous high sensible heat load application comprises a cooling mode system, a free-cooling mode system and a controller. The cooling mode of the system includes a refrigeration circuit having a compressor, Condenser coil, Evaporator coil, and an expansion device having a variable opening. The controller selectively operates the system in the cooling mode by circulating and compressing a refrigerant through the refrigeration circuit via said compressor and in the free-cooling mode by forcefully circulating outdoor-air in the enclosed space. A free-cooling limitation and variation sequence resides on said controller.
In general, free cooling mode is used when the outdoor-air temperature is comparatively lower than the specified temperature inside the enclosed Space. During free cooling the cooling mode system is automatically switched-off and

outdoor air is forcefully allowed-in by using electrically operated blower or fan for this purpose, thereby maintaining the enclosed space temperature within specified limits. The airflow of this fan of the present air conditioning systems is fixed irrespective of the outdoor temperature. Further, when the outside temperature is too low or below 0 Deg C, the continuous running of free cooling may cause damage to the Telecom Products / Instruments working in the specified enclosed space.
An air conditioning system for continuous high sensible heat load application for an enclosed space is described in 2514/MUM/2008 which utilizes the concept of controlling the speed of the fan for appropriately cooling the system. However, the evaporator fan running in free cooling mode consumes electrical energy.
It is therefore desired to improve existing systems by providing an alternate system for cooling the enclosed space shelter.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an air conditioning system for a shelter including telecom cabinet. The said air conditioning system comprises at least one window opening for air flow between atmosphere side and enclosed space, a cooling mode system including a refrigeration circuit, a free-cooling mode system, a plurality of temperature sensors for sensing the temperature inside and outside of the enclosed space, and a controller means. The free cooling mode system has a compressor, a condenser coil, evaporator coil, and an expansion

device having a variable opening connected in the required order. The free-cooling mode system comprises a first damper adapted at the window for directing air-flow adapted on an inlet for outer air and atleast one turbine-ventilator provided on top of the cabinet with a second damper, the turbine ventilator powered by wind for creating effective ventilation and the controller controls opening of the first and second damper when the system operates on the free-cooling mode in order to cause air flow by use of turbo-ventilator for maintaining the temperature of the enclosed space within a predefined range.
DESCRIPTION OF THE DRAWINGS
The preferred embodiment of the present invention will now be described with reference to the accompanying drawings, which are given by way of example and are not to be taken as limiting in any way. The accompanying drawings are intended to make the invention easier to understand. Figure 1 shows a telecom cabinet with a turbo-ventilator.
BRIEF DESCRIPTION OF THE INVENTION
It is an object of the present invention to provide an enclosed space telecom shelter cabinet with a system for continuous high sensible heat load application to obviate the short comings associated with the prior arts.

In general, the present invention provides a cabinet for air conditioning system having a cooling mode system, a free cooling mode system, temperature sensors for sensing the temperature inside and outside of the enclosed space and a controller means for operating the system in cooling or free cooling mode. The cooling mode system includes a refrigeration circuit having a compressor, a condenser coil, evaporator coil, and an expansion device having a variable opening connected in the required order.
In an embodiment, the present invention provides an air conditioning system for continuous high sensible heat load application in a telecom cabinet, comprising: at least one window opening for air flow between atmosphere side and enclosed space; a cooling mode system including a refrigeration circuit having a compressor, a condenser coil, evaporator coil, and an expansion device having a variable opening connected in the required order; a free-cooling mode system having a damper adapted at the window for directing air-flow adapted on an inlet for outer air and a turbine-ventilator provided with the damper, the ventilator adapted on the telecom shelter, the turbine ventilator powered by wind for creating effective ventilation; a plurality of temperature sensors for sensing the temperature inside and outside of the enclosed space; and a controller means for controlling opening of the damper when the system operates on the free-cooling mode in order to cause air flow by use of turbo-ventilator for maintaining the temperature of the enclosed space within a predefined range.

According to the present invention, the cabinet for the free-cooling mode system includes atleast one damper for directing air-flow adapted on an inlet for outer air and a motor for opening and closing the damper. According to the present invention, the controller means controls opening of the damper when the system operates on the free-cooling mode in order to cause air flow with the use of turbo-ventilator for maintaining the temperature of the enclosed space within a predefined range.
As per one exemplary embodiment the present invention a turbine ventilator is adapted on the cabinet of the air conditioning system. The Wind turbine ventilators or Turbo-ventilator is a ventilator that is powered by the wind to create effective ventilation for enclosed space. The principle energy is wind as the turbine ventilator works on wind assisted ventilation. The turbine ventilator is a round metal vent with fins accommodated to them. The advantage of this component is that even a little bit of wind can be just enough for the turbo ventilator to rotate. The faster the wind, the faster the turbine will rotate and exhaust the internal air of the cabinet.
As per one additional aspect of the present invention, the hot air inside the shed tends to rise up and exert force on the vanes of the turbo ventilator, making it to rotate. When the turbines rotate, they suck the outside warm air through the vents and thereby causing a drop in temperature in the enclosed space and allow supply of fresh air through dampers.

The air flow intake happens by the virtue of turbo ventilator which is driven by hot air rising inside the enclosed space of the cabinet. The air flow for cooling the cabinet is controlled by controlling the opening of the damper during free cooling.
Referring to figure 1, an exemplary embodiment of a cabinet with an air conditioning system is shown, generally referred to by reference numeral (100). The system cabinet (10) is configured to operate in a cooling mode and a free cooling mode. The integrated solution for sensible heat load application consists of a cabinet (10) wherein a turbo-ventilator (20) and/or a damper (30), a refrigeration circuit (40) are placed. The directional flow of air from inside the cabinet is also shown in the Figure.
The present invention also provides a method for maintaining the temperature within the predefined range by using an air-conditioning system, the method comprising steps of determining the difference between ambient temperature and enclosed space temperature, operating the system in the cooling mode if the enclosed space temperature and the outside temperature are above the higher set point of predefined temperature range, operating the system in free cooling mode if the enclosed space temperature is above the higher set point of predefined temperature range and more than the outside temperature wherein out-side airflow entering in the enclosed space is controlled by opening and closing of damper for maintaining the temperature of the enclosed space within a predefined

range. The free cooling system generally operates when outside temperature is lower than the higher set point of the predetermined temperature of the enclosed space.
As per one embodiment the method also includes a step of stopping the free cooling by completely closing the dampers if the temperature of the enclosed space decreases below the lower set point to maintain the temperature of the enclosed space within the defined range.
The advantage of the present invention that it provides a free cooling system for enclosed space, substantially saves electrical energy cost as compared to existing free cooling systems and enhance refrigeration system life, controls the air flow amount, when the outdoor air temperature is too low or below 0 deg C and does not affect the performance of Telecom products / Electronic Instrument kept inside the enclosed space, thus improve the performance and enhance the life of the products / instruments kept inside.
In the description of the disclosure, for purpose of explanation, specific details are set forth in order to provide an understanding of the invention. It will be apparent, however, to one skilled in the art that the invention may be practiced without these details. One skilled in the art will recognize that embodiments of the present invention, some of which are described above, may be incorporated into a number of enterprise resource planning systems. Structures and devices shown in the

figures are illustrative of exemplary embodiments of the invention and are meant to avoid obscuring the invention.

We Claim :
1. An air conditioning system for a shelter including telecom cabinet, comprising:
at least one window opening for air flow between atmosphere side and enclosed space;
a cooling mode system including a refrigeration circuit having a compressor, a condenser coil, evaporator coil, and an expansion device having a variable opening connected in the required order;
a free-cooling mode system having a first damper adapted at the window for directing air-flow adapted on an inlet for outer air and atleast one turbine-ventilator provided on top of the cabinet with a second damper, the ventilator adapted on the telecom shelter, the turbine ventilator powered by wind for creating effective ventilation;
a plurality of temperature sensors for sensing the temperature inside and outside of the enclosed space;
and
a controller means for controlling opening of the first and second damper when the system operates on the free-cooling mode in order to cause air flow by use of turbo-ventilator for maintaining the temperature of the enclosed space within a predefined range.
2. The system as claimed in claim 1, wherein the system further comprises a motor for opening and closing the first damper.

3. The system as claimed in claim 1, wherein the turbine ventilator is a round metal vent with fins accommodated to them, the turbo-ventilator rotates to take-in and out-throw the air through vent and thereby causing a pressure drop in the enclosed space and allowing supply of fresh air through dampers.
4. The system as claimed in claim 1, wherein air flow intake is initiated by the virtue of turbo ventilator in combination with window wherein the air flow for cooling the cabinet is being controlled by controlling the opening of the damper during free cooling.