An efficient air conditioning system, as well as the installation of modern energy-saving technologies are also used in means of tourist transport. Below we will see an example of this.
by Alfredo Sotolongo*
It is very interesting that as a result of the increase in fuel all responsible companies try to minimize energy consumption. This not only applies to our air conditioning industry but to many other types of industries. In this article I propose to analyze the sector of tourist cruise ships.
As many of you know, our company Protec celebrates its 40th anniversary next year and we will celebrate it on a Caribbean cruise. We have organized an incentive plan for air conditioning contractors. Those who accumulate in purchases during the year 2012 a certain amount, earn a cabin to accompany us in such an important event. We will also be joined by a select group of consulting engineers who through those 40 years have trusted us and helped us become the company we are today.
We have chosen the Celebrity shipping line and its latest ship, Reflection, not only for its comforts, unbeatable service and excellent food, but for the state-of-the-art engineering applied to its operation and energy conservation. This beautiful ship left the shipyard in October and we are almost launching it in April 2013.
It is important to note that this ship has the following specifications:
- Length = 320 meters (1,050 feet)
- Beam (width) = 38 meters (125 feet)
- Draft = 8.2 meters (27 feet)
- Capacity = 126,000 tons
- Passengers and crew = 3,046
- Cruising speed = 24 knots
It is operated by four 14-cylinder electric generators using diesel fuel, which produce approximately 224 megawatts and consume 63,000 gallons of fuel per day. In the combustion exhaust of the generators, heat exchangers were located to recover energy that was previously wasted to the environment, with this energy the water is partially heated for domestic use.
The electricity consumption is distributed as follows:
- Propulsion = 60%
- Hotel operation = 16%
- Auxiliary machines = 13%
- Air conditioning = 11%
It is in the propulsion where the newest concepts of naval engineering have been applied since it represents the highest consumption. From the alternating current generators it is passed to the direct current converters, which in turn, feed the two motors called Azipod with the propeller directly coupled. These motors operate at a maximum speed of 130 RPM and through a hydraulic system can rotate 360⁰. They are located near the stern and outside the hull, designed to minimize resistance and vibration. They also act as rudders achieving a faster and more effective reaction when compared to the old, better-known system of shaft, propellers and rudders.
In addition, the torpedo-shaped piece, located on the bow just below the surface, called the "Forebody", was redesigned. It helps to break the waves much more effectively and is also combined with another piece called "Interceptor" that is located at the stern and helps to lift it. This combination of the "Forebody" and the "Interceptor" means that the propulsion requires less electrical consumption for its operation.
In the area of cabins and hotel service, all the energy saving systems available at the time of construction have been used. As far as lighting is concerned, LEDs and solar collectors have been used that generate approximately 45 kW, which can power up to 7,000 LED lights.
In the air conditioning system everything is used with variable volume so that by reducing the volumes, the electricity consumption is reduced exponentially. In addition, they have thermal insulation in pipes and air conditioning ducts with the highest "R" factor available. All window panes, in areas exposed to the outside, were covered with a film of a transparent material that reduces ultraviolet rays by up to 99%, which helps to considerably reduce the thermal load of such areas.
In keeping with our energy-saving culture, we consider that we have selected the most efficient cruise ship to hold our grand convention and celebrate our 40th anniversary in style.
If you require more information on any of the topics covered in this column, you can contact me at the email [email protected]
* President of Protec, Inc., is certified as a professional engineer in Puerto Rico and the state of Florida; he has more than 40 years of experience in the application and sale of systems and equipment for energy conservation. He is a member of ASME (American Society of Mechanical Engineers), AEE (Association of Energy Engineers), ASHRAE and was president of the Miami chapter of that association.
