Singaporean engineers have come up with a smart quad-generation plant that produces electricity, water, air-conditioning and heat within a single, integrated system.
The researchers, led by Associated Professor Ernest Chua from the Department of Mechanical Engineering at National University of Singapore (NUS) specially designed the eco-friendly system for use in tropical countries. It is suited for housing and building clusters and underground cities, and harvests waste energy, and is said to significantly reduce carbon dioxide emission by more than 30 percent.
According to Chua, significant amounts of energy is currently needed to generate electricity, water, air-conditioning and heat.
“Running four independent processes also result in extensive energy wastage, and such systems take up a huge floor area. With our smart plant, these processes are carefully integrated together such that waste energy can be harvested for useful output,” he said.
This integrated approach could reduce both the physical size of the unit and the energy required.
The smart plant uses natural gas to power micro turbines to produce electricity. Waste heat generated from exhaust gas in the process is efficiently recovered and channelled back to power chillers to produce chilled water, which is then used to cool and dry air for air-conditioning.
The plant is also able to recycle non-potable water, such as rain water and water discharged from showers and wash basins, to produce drinking water. Waste heat generated from the plant could also be used to produce hot water or steam.
The quad-generation plant incorporates a dual-dehumidification system designed by the NUS Engineering team. This system uses super adsorbent materials and membranes to remove up to 50 to 60 percent of moisture from air, improving the efficiency of the air-conditioning system.
Another improvement is the ability of the system to cool air with water that is chilled to just 13 to 18°C, instead of the usual lower temperature of 4 to 7°C. This improves the plant’s efficiency, reducing the energy required to chill water.
The NUS Engineering team also incorporated smart features into the plant, such as real-time tracking of power consumption, and the ability to control valves and pumps remotely, allowing for remove energy efficiency monitoring and optimisation.
“The quad-generation plant is designed to be a distributed power entity,” Chua explained.
“As power grids could be vulnerable to national security threats, our smart plant could also serve as a resilient distributed energy resource to continue to provide these essential utilities and minimise disruptions to daily lives.”
[Dr Md Raisul Islam (left) and Associate Professor Ernest Chua. Photo: NUS]