South Korean environmental and energy company SK ecoplant has succeeded in developing a cooling and heating system that utilizes the unique characteristics of solid oxide fuel cells (SOFCs) that operate at high temperatures.
Together with Samjung Tech, SK ecoplant announced on September 21 that it has applied for and obtained a patent for "High-efficiency integrated absorption heating and cooling system utilizing fuel cell array" and is promoting its application to actual projects. Samjung Tech, which co-developed the patented technology, specializes in absorption air conditioners.
Absorption heating and cooling systems work on the principle that the evaporation and absorption temperature of water varies depending on the pressure. Water normally boils at 100℃, but an absorption heating and cooling system creates a pressure (6.5mmHg) that is close to a vacuum, allowing water to boil at just 5℃.
As the water boils at a lower temperature, it evaporates and acts as a refrigerant to cool the surrounding area. In the case of heating, the heat input is used to produce hot water, and the water vapor from the heat input is absorbed and reused in a cycle.
Absorption heating and cooling systems have been widely used for heating and cooling in centrally air-conditioned buildings such as shopping centers, hospitals, and offices. However, while conventional systems use hot water and fossil fuels such as gas and oil as heat sources, this patent is significant in that it utilizes the exhaust of fuel cells that have been discarded as heat sources.
In the case of the system developed by SK ecoplant, the 300~400℃ fuel cell array is used as a heat source to produce 7℃ cold water, which is used to cool buildings.
SK ecoplant plans to apply the system to a 19.8MW fuel cell power plant to be installed in the second half of this year. Construction of the plant is scheduled to begin in September this year, with installation and commissioning scheduled for early next year.
In the current simulation stage, it is expected that the absorption water heater applied to two sets of fuel cells (SOFC 600 kW) will be able to run about six 35 kW air conditioners through thermal energy in addition to generating electricity.
In order to make the most of waste heat, SK ecoplant plans to apply absorption cooling and heating systems to all fuel cell power plants with an installed capacity of 15 MW or more in the future to meet the cooling and heating needs of electrical rooms.
"The integrated application of absorption heating and cooling systems that strategically utilize fuel cell arrays to fuel cell demand is expected to reduce costs and replace fossil fuels for heating and cooling," said Lim In-mook, Executive Officer of SK ecoplant's Energy Operation.
