Feasibility study of industrial waste heat recovery in Singapore

Abstract

The potential sources of cooling energy are abundant. In Singapore‟s context, there are the LNG terminals in Jurong Island and Tuas as well as waste heat potentials from Gas Power plants, waste incinerators and from relevant industries. Waste heat potentials are available from technical industries as well as commercial and residential ones. For this project, it will be based on tapping waste heat from gas power plants, waste incinerators as the bulk of the waste heat originates from these sources. LNG terminals are also included in as the cooling available here are associated with the system that we are interested in. The implementation of industrial chillers to tap on waste heat and to meet the cooling energy demands. From these chillers, we will then move on to designing pipe outlines so that we can transport the chilled water to the relevant sectors using this cooling energy. This harvesting and implementation of waste heat potentials are incorporated into a district cooling system (DSC). Since Singapore is still not fully convinced by this cooling energy vector, this report is about conducting a feasibility study to outline the advantages and disadvantages of such a system. The designing of the piping outline is done using the URA masterplan website where it provides the gross area ratio and the land areas that we want to cover with the DSC. The piping outline that was designed managed to cover up to three-quarter of Singapore‟s land area. After establishing the piping outline, the Energy use intensity for the different sectors is based on the assumptions that the commercial and residential sector uses the value of 215 kWh/ per annum and 55 kWh/ per annum respectively. Potential sources of waste heat energy were identified and calculated to ensure the energy demands of the different sectors are met. The single phase LiBr-water absorption chillers are used for the simulation as it is an economical and environmental alternative for the ii conventional refrigeration. Potential losses for the DSC are also taken into account such as heat losses and pressure losses. These calculations of potential cold production and losses are done through simulations of the Matlab software. After the simulations are conducted, the results shows that the losses calculated are at the optimal range of 5 to 10% which is the efficiency that a DSC should adopt. The cold production are almost twice as much as the energy demands of the sectors that shows us that DSC is a very viable system for Singapore to adopt. The results are collated into weekly values for ease of comparison. Since the areas of research of DSC in Singapore are limited, the project provides the initial values and assumptions to observe the feasibility of DSC in Singapore. Therefore, there are still rooms for further research on implementing this system in Singapore and more variables to take into account when incorporating DSC in Singapore.