The following stories from Serbia are extracts from the booklet 'Women in the Refrigeration and Air-Conditioning Industry."
STORY BY NEVENA AKSIC
When I started studying for my Bachelor’s degree I knew I wanted to work in the weld of energy and process sciences. My professors saw my passion, so they started giving me higher expectations and more literature. Today I’m in my final year of my Bachelor’s studies, preparing the final essay on an industrial refrigeration topic, which is my own startup business.
- "When I was 15 my father asked me if I would like to come with him to one of the construction sites to see how industrial refrigeration worked. It was love at first sight.”
Last year the dreams started to become real; my idea was to save F-gases from being banned, but also to make it impossible for them to leak from systems. This started as laboratory research, and very soon I won my first awards for student research (even though I was the youngest). Then everything started to happen by itself. I started developing a business and won the first prize in a national competition for green business ideas and the chance to represent Serbia in the global competition, where my idea reached the finals. I won five more awards for Innovative Green Business ideas.
Only my father believed that a really young girl from Serbia could do big jobs in the Refrigeration industry globally, and he was right. My first application of an innovative solution will be this October in Vigo in Spain. But it has also brought me work in my own country. Cold storage owners have come to see me as fresh and innovative, and from thinking that construction sites are not for young girls, they now say I am the one they trust.
I won’t stop developing my knowledge of industrial refrigeration until I make my name in the history of refrigeration.
STORY BY ŽELJKA VUKOVIC
I graduated in 2004 from the Department of Thermo Techniques at the Faculty of Mechanical Engineering at Belgrade University. I began to work in the weld of RAC in 2004. My first experience was in the production of compressor racks, condensing units, monoblocks and chillers with HCFC. In 2006, at the International Fair of Technique and Technical Achievements, the compressor rack with two temperature modes suitable for supermarkets that I constructed as an employee of Soko Engineering received the first prize.
After experience in production, I designed central refrigeration installations with HCFC for supermarkets, cold stores and cold rooms for cooling and freezing food. In order to obtain more complete experience in the field of refrigeration, I followed the implementation of cooling installations in the facilities, and I put the cooling systems into operation. For most installations I set up and put into operation a system for monitoring and managing the operation of cooling installations, working together with the installers.
Through attending congresses, lectures and exhibition fairs in developed countries, reading scientific journals in the RAC field and informing myself about the trend towards eliminating Freon (even HCFC) in refrigeration installations generally, I began to explore the current state of cooling installations in our country (type of system, type of refrigerant, Freon leakage rate, etc.). In 2010 and 2011 I collected recorded data for refrigeration installations in 46 existing supermarkets in Serbia showing the amount of supplementary refrigerant used in refrigeration systems. The study determined the amount of refrigerant that was leaking out of the systems. This research showed that Freon leakage rate in Serbia was significantly higher in comparison to more developed countries. Following that research, as a team of technicians, engineers, installers and repairers, we worked on reducing the amount of Freon released from the system into the environment. We applied many constructive design solutions, whereby the Freon leakage rate was reduced to the average level in more developed European countries.
After the success achieved in reducing the amount of Freon released from the existing systems into the environment, I felt motivated to further reduce the negative impact of cooling systems on the environment. The result has been the development of a system with natural refrigerants for use in new cooling installations.
- “I felt motivated to further reduce the negative impact of cooling systems on the environment. The result has been the development of a system with natural refrigerants for use in new cooling installations.”
Nine years ago, we started research and development of a cascade refrigeration plant with CO2, and eight years ago we created a small refrigeration installation project for three cold rooms. This type of mixed system with flooded and direct expansion (DX) systems is suitable for supermarket refrigeration systems, where two temperature levels are required. This system was developed, manufactured, tested and put into operation in the Soko Engineering factory.
During my work in the RAC field, I have designed reconstructions of large cooling systems in distribution centres. This was a challenge owing to the size of the systems, their age and the fact that the cooling fluid in these systems is ammonia, which is inflammable and explosive.
In the past few years, the construction of large distribution centres in Serbia has begun. All the investors in this area have a green profile, and refrigeration installations in these distribution centres should be environmentally friendly. During this period, I have designed large cooling systems in distribution centres. From the point of view of environmental protection, energy efficiency and investment value as an optimal solution, we chose an ammonia refrigeration system in cooperation with the investor.
After a long period of several decades, these were the first major projects in Serbia to involve ammonia refrigeration systems. With a team of engineers, I designed an ammonia refrigeration system for a 78,000 square km. distribution centre, of which 22,000 square km. was cooled. We also designed an ammonia cooling system for a 46,000 square km. distribution centre, with 14,000 square km. cooled. These systems are designed in accordance with the latest knowledge in the weld of refrigeration, with special emphasis on human safety and environmental protection. The size of the cold stores and the available time frame made it a challenge to finish them on time. These projects were successfully completed on time, and now they are running to the owners’ satisfaction.
In addition to design and implementation of refrigeration systems for supermarkets, cold stores and cold rooms for food, I have designed and supervised the implementation of refrigeration systems for cooling machines in the food and plastic products industry. Designing such systems is a challenge since they are all custom-made. They are demanding because they have very variable operating parameters, and the quality of the final product depends on the quality of the design and adaptability of the cooling system.
The latest development project I have worked on is for Trans Critical Cooling Systems with CO2. At the Soko Engineering factory, we started the development of Trans Critical Cooling Systems with CO2 for supermarkets. We have completed the pilot project and are currently in the process of procuring equipment for this project. We plan the completion and commissioning of this project for the beginning of September this year.
At the same time, we designed a Trans Critical Cooling Systems with CO2 for the supermarkets of a large retail chain in Serbia. Work on this project and commissioning of the facility will be completed by the end of 2018.
I am also a member of the Serbian Chamber of Engineers and the Serbian Society for HVAC (SMEITS). I have presented my experience and the Soko Engineering experience in the weld of air conditioning, heating, and cooling at several international congresses. The papers I wrote were published in international scientific journals, as well as in the proceedings of some of the international congresses.
