Details about the project to modernize the air conditioning systems of the Caracas Metro, Venezuela, narrated by its systems maintenance coordinator.
by Jimy Danelli*
My name is Jimy Danelli I am 52 years old, I am an average refrigeration and air conditioning technician graduated from the Industrial Technical School "José de San Martin" in Caracas, I did higher education studies obtaining the title of Professor in Commercial and Industrial Education. I started my career as a maintenance technician in air conditioning systems in 1988 and at the same time I continued my higher studies.
During my career in the company Metro de Caracas I was promoting positions and providing solutions to the different problems that arose in the systems of air conditioning, ventilation, compressed air, low voltage electricity, pumping, among others. I participated in the first Engineering Days in 1998 with the project "Maintenance of Air Conditioning Systems" then in 2000, in the second Engineering Conference, I participated with the Project Self-cleaning System of filters for the Air Handling Units of the Caracas Metro stations, obtaining the second place in these Days.
In the 3rd Conference I competed with the Project "UVC Lamp Systems to improve the quality of the air that is supplied to stations and offices of the C.A. Metro de Caracas". Take a Diploma in Energy Efficiency, in addition to more than 38 training courses in planning, design and maintenance of air conditioning, ventilation and other electromechanical systems inside and outside Venezuela.
I currently work as Maintenance Coordinator of Air Conditioning Systems for the stations of Lines 2, 4, 5 and Metro Los Teques; and in addition, I manage the monitoring and control system of the air conditioning systems, stairs and drainage and bilge pumping of the C.A. Metro de Caracas.
The company where I work, belonging to the Venezuelan state, of public transport Metro de Caracas, is constituted by five underground and elevated metro lines, with metrobus feeder systems, cable metro system (cable car type) and cable train system, which require air conditioning systems to condition the areas of service to the public in stations and buildings.
The initial project dates from 1965 and the beginning of its construction begins in 1974, at that time the refrigerant used for the operation of the equipment were the now extinct R22, R11 and R12. By then, the air-conditioned stations were configured from central Refrigeration Plants which provided ice water through a network of pipes that runs through part of the city on the same route of the metro network.
The first section opened in 1983, the Propatria section (west of the city of Caracas) to the Chacaito station (east of the city) had three large plants with three chillers of 800 tons each, with R11 refrigerant, feeding three stations with ice water. For the year 1987 the opening of line 2 and the applications of line 1 continued until completing this line with stations from Propatria to Palo verde in the east of the city. Then in 1993 line 3 was inaugurated that connects the central area of the city with the south of Caracas, in the populous neighborhood of the valley and the Riconada.
All these stations have a supply of 100% fresh air motivated by the fact that they are underground, semi-elevated and elevated. This air passes through the filtering system and then passes into the coils of the UMAS. With the entry into force of the Montreal and Copenhagen protocols and Venezuela being a signatory to these protocols, it was required to evaluate the replacement by equipment that did not require ozone-depleting gases. In a first instance in 2005 began to replace a cooling plant, number 2 located in the central area of the city of Caracas and which supplied ice water to stations with a greater influx of passengers, there were replaced three chiller of R11 by equipment of R134a centrifuges cooled by water, likewise the auxiliary equipment, ice water pumping, condensed water pumping and cooling towers.
Equipment replacement
From the year 2009 a project called modernization of the air conditioning was started, this project was carried out with the aim of replacing equipment that contains exhausting gases of the ozone layer and that on the other hand had a high energy consumption, for that year I am assigned the responsibility of leading that project, initiated with the elaboration of technical specifications that would allow adapting the new technologies to the metro system.
An important aspect was to develop the proposed works without the interruption of service that is provided to the users of the system.
By October 2010, the acquisition of 35 chillers of different capacities (22 air-cooled chillers of 150 tons with scroll compressors; 5 chillers of 80 tons; 1 of 40 tons with R410a refrigerant and 5 chillers, of 800 tons, centrifuges cooled by R134 a refrigerant water, was completed. In this same way, the coils of the 120-ton air handling units were incorporated to replace in the stations of lines 1, 2, 3, the pumping of ice water, the equipment and accessories necessary for its proper operation.
The project began with the dismantling of old equipment, chillers, coils, fans and other components that were contemplated to modernize. By March 2011 the first equipment arrived and the transfer and installation began in the different stations of line 1. In this project, resources were optimized by maintaining part of the infrastructure of pipes and electrical connections initially installed. In the works the C.A. Metro de Caracas subcontracted the installations and mechanical connections of the equipment, and with its own personnel undertook the electrical installations of most of these equipment. Eight months after this modernization project started, the facilities were completed, training courses were given and the installation of a monitoring and control system for air conditioning equipment began, in addition to incorporating the monitoring of escalators and bilge pumping for the stations and buildings of the Caracas Metro, since a cooling capacity of more than 8000 tons had been installed, incorporating other facilities not included in the Modernization Project. This system was connected to the fiber optic network installed in the Caracas Metro system, which allows remote monitoring and control of temperatures, start and stop scheduled by the hour and day, which allows an optimization of energy consumption incorporating state-of-the-art technology for the efficient use of energy.
Currently it is about to install five chillers more than 40 tons and 17 of 20 tons with refrigerant R410a with scroll compressors on line 1 Propatria-Palo verde, for the air conditioning systems totally independent for the technical rooms of train control, this motivated to the fact that the new generation trains incorporated for line 1 have technology a control with electronic cards that require a temperature control according to the operating requirements.
All these projects developed and completed have provided a better quality of life for Caracas, since it has contributed to the reduction of the use of the refringents depleting the ozone layer, in addition to the reduction of energy consumption that in the same way decreases the emissions of greenhouse gases by incorporating systems that control the air conditioning equipment being the largest consumers of energy.
On the other hand, the work I develop in the Caracas metro is not only technical, I also contribute to the training of apprentices in maintenance, refrigeration and air conditioning, controls and others framed in the technological development that countries need for their independence and development, despite the political and economic difficulties that Venezuela has suffered, work continues to improve the service that this prestigious transport company continues to provide to the citizens of Caracas.
* Jimy Danelli is an HVAC technician and works in the maintenance and administration of the air conditioning systems of the Caracas Metro.
