Erosion-corrosion of elbow configurations has recently been a momentous concern in hydrocarbon processing and transportation industries. The carbon steel 90° elbows are susceptible to the erosion-corrosion during the multiphase flow, peculiarly for erosive slug flows. This paper studies the erosion-corrosion performance of 90° elbows at slug flow conditions for impact with 2, 5, and 10 wt.% sand fines concentrations on AISI 1018 carbon steel exploiting quantitative and qualitative analyses. The worn surface analyses were effectuated by using laser confocal and scanning electron microscopy. The experiment was conducted under air and water slug flow containing sand fines of 50 µm average size circulated in the closed flow loop. The results manifest that with the increase of concentration level, the erosion-corrosion magnitude increases remarkably. Sand fines instigate the development of perforation sites in the form of circular, elongated, and coalescence pits at the elbow downstream and the corrosion attack is much more obvious with the increase of sand fines concentration. Another congruent finding is that cutting and pitting corrosion as the primitive causes of material degradation, the 10 wt.% sand fines concentration in carrier phase increases the erosion-corrosion rate of carbon steel up to 93% relative to the 2 wt.% sand fines concentration in slug flow.

This study’s primary goal is to evaluate the performance of a large thermal energy storage tank installed in a Gas District Cooling (GDC) plant. The performance parameters considered in this study include thermocline thickness (WTc), Cumulated Charge (Q_cum), and Half Figure of Merit (½ FOM). The operation sensor data of a large Thermal Energy Storage (TES) tank was acquired for this analysis. The recorded temperature sensor from the 1st to 7th January and from 12th to 17th October 2019 was considered in this research. GraphPad prism computer software was deployed for analyses, and the temperature distribution data were analyzed to determine the four temperature parameters (hot water temperature (Th), cool water temperature (Tc), cool water depth (C), and slope gradient (S)) using a non-linear regression curve fitting technique and sigmoid Dose Responses function as integrated with the software. At the end of this research, the relationship between the growth of the determined performance parameter with charging hours was analyzed and presented. The research results proved the ability of GraphPad Prism software to assess the temperature distribution in the TES tank and also the corresponding effects on the overall Tank performance. The software offers better advantages in evaluating the performance parameter of the TES tank accurately.

District cooling (DC) systems have recently proven to be more economically and environmentally viable as compared to conventional cooling techniques. In most DC setups, electric centrifugal chillers (ECCs) are installed to provide chilled water (CW) to charge the thermal energy storage (TES) tank or for direct CW supply to the DC network. The operation of these ECC systems consumes most of the electrical power supplied to the entire DC plant; this therefore strengthens the need to conduct a comprehensive environmental assessment in order to quantify the indirect ecological impact resulting from the energy consumed in the ECC system operation. In order to achieve this, a case study was conducted of four ECC systems with a use-life of 25 years installed in a large DC plant in Malaysia. A gate-to-gate life cycle assessment (LCA) methodology was adopted to analyze the environmental performance of the system setup. The result of the study year reveals that April and June account for the highest and lowest environmental impact, respectively. The influence of climatic temperature conditions on the monthly cooling and environmental load distribution was also observed from the results. Finally, in substantiating the study’s investigation, environmental performance based on the composition of two different electricity fuel mixes is discussed and compared. The results revealed a drastic decrease in environmental load as the ratio of non-renewable energy sources decreased in the composition of the mix, thereby reducing the contribution of the overall environmental impact of the ECC systems’ use phase.

In order to cater for increased demand for natural gas (NG) by the industry, Malaysia is required to import liquid natural gas (LNG). This is done through PETRONAS GAS Sdn Bhd. For LNG regasification, two regasification terminals have been set up, one in Sungai Udang Melaka (RGTSU) and another at Pengerang Johor (RGTPJ). RGTSU started operation in 2013 while RGTPJ began operation in 2017. The capacities of RGTSU and RGTPJ are 3.8 (500 mmscfd) and 3.5 (490 mmscfd) MTPA, respectively. RGTSU is an offshore plant and uses an intermediate-fluid-vaporization (IFV) process for regasification. RGTPJ is an onshore plant and employs open-rack vaporization (ORV). It is known that a substantial amount of cold energy is released during the regasification process. However, neither plant captures the cold energy released during regasification. This techno economic study serves to evaluate the technical and economic feasibility of the cold energy available during regasification. It was estimated that approximately 47,214 and 88,383 kWh of cold energy could be generated daily at RGTPJ and RGTSU, respectively, during regasification processes. Converting this energy into RTh at 70% thermal efficiency, and taking the commercial rate of 0.549 Sen per RTh, for the 20-year project life, an internal rate of return (IRR) of up to 33% and 17% was estimated for RGTPJ and for RGTSU, respectively.

Thermal energy storage (TES) is the key component of the district cooling (DC) plants. Its performance is important to be analysed. Various works have been carried out to analyse the TES tank performance. Among the methods, the most common are thermocline thickness and figure of merit. In this study nonlinear regression is used to analyse the temperature profiles of a stratified TES tank at DC plant at Universiti Teknologi PETRONAS. The TES performance was also evaluated using thermocline thickness and 1/2FOM. Results indicate curve fitting approach is enabled to plot temperature profiles during charging. The plots assist in understanding the development of thermocline within the TES tank during charging process. Results on the thermocline thickness and 1/2FOM during the understudy charging period indicate increased of thermocline thickness and decreased of 1/2FOM values respectively during the study period. Hence it can be concluded that deterioration occurred to the TES tank during the study period.