Abstract

Semiconductor or optoelectronic manufacturing is a high-energy consumption industry in Taiwan. Detailed energy consumption data for a manufacturing plant (called fab) is important to calculate energy savings and for energy management. The objective of this study is to integrate the fab energy simulation (FES) tool and energy conversion factor (ECF) to analyze the energy use of high-tech fabs and to identify some possible energy savings from the results. We used data from a Taiwanese semiconductor manufacturing fab as an example. In addition to the process equipment, the highest energy consumers in the fab were the compressed (or clean) dry air (22.1%), water chiller (20.6%), process cooling water (5.8%), de-ionized water (3.2%), and exhaust systems (2.0%). When compared to the original data, the results from the studied case showed that the highest energy savings for the compressed (or clean) dry air system were 3,050 MWh (1.81% of the overall energy consumption).

Abstract

H2 production through water electrolysis for power-to-X applications is being investigated by comparing different bidding strategies on the electricity spot market in Sweden. For that, a price independent order (PIO) strategy was developed assisted by forecasting electricity prices with neural networks (NN). For comparison, a price dependent order (PDO) with a fixed bid price was used. The optimization of the NN showed that increasing the number of neurons in the hidden layer did not reduce error in forecasting due to possible overlapping of data making the model unnecessarily complex. By using different combinations of data for in-sample training and data from 2016-2018 for out-of-sample testing, preliminary results showed similar trends for PIO and PDO when bid prices are increased. However, the PIO marginally reduced the average cost of electricity when compared to PDO in all scenarios, but this was at the expense of increased non-operating hours (cold and warm mode). Further investigations with a mathematical optimization approach will reveal ideal conditions to run the system with low H2 production costs and increased profitability.

Abstract

The distribution models of naturally occurring gas hydrates in sediments are diverse and have significant influence on physical properties of rocks. In this work, acoustic properties of hydrate-bearing sediment with homogeneous distribution or heterogeneous distribution were investigated using an in situ measurement apparatus, in which methane was used as a free gas for forming hydrate. Hydrate-bearing sediments with homogeneous or heterogeneous distribution were synthesized by controlling the system temperature and water migration. The influence of water migration as a result of gravity along with the rising temperature on acoustic properties was examined during the hydrate formation process. The results showed that the memory effect was proved to be exist from macroscopic scale. Hydrate distribution and concentration are all of great significance to the acoustic characteristics for hydrate deposits. And it was found that the P-wave velocity of the hydrate deposits with homogeneous distribution is faster than that with heterogeneous distribution when under a same hydrate saturation.

Abstract

Soft open point (SOP) refers to a novel power electronic device installed in active distribution networks (ADNs) to replace traditional tie switch. When a fault occurs, power outage areas are formed after fault location and isolation, SOP can provide voltage and power support for the outage areas, which improves the power supply reliability of ADNs. In this paper, a reliability index calculation method based on fault incidence matrix is used to calculate the reliability indexes of nodes and system. The principle of reliability improvement based on SOP is described, and the influence factors of SOP affecting the reliability of ADNs are analyzed. Compared with traditional tie switch, the integration of SOP can effectively improve the power supply reliability of ADNs. As the impact of position and capacity of SOP on supply restoration, it also significantly influences reliability improvement. The analysis of reliability improvement based on SOP is demonstrated on modified IEEE 33-node system.

Abstract

Solvent absorption is currently the main decarbonization method, in which propylene carbonate (PC) washing is widely applied in virtue of its low material loss and simple process. In regard of the low solubility and selectivity to CO2 of PC, traditional PC washing process is improved by adding 2- methylimidazole (2-mIm) and water as additives to PC. In this paper, firstly the miscible point of 2-mIm-waterPC three phase system as well as saturation point of 2- mIm were measured, so was the viscosity of mixture solvent. Next, the solubility of CO2 in mixture solvents with different proportion was measured to make a comparison with that in pure PC, where temperature was in 298.15 and 308.15 K, pressure was in the range of 0.01-1.40 MPa. The heats of CO2 absorption in these solvent mixtures were calculated using the ClausiusClapeyron equation. Then the kinetic curves of pure PC and mixture solvents were measured, and solvent 2 (2- mIm 16.7 wt% + water 8.3 wt% + PC 75 wt%) showed an comparable absorption rate to that of pure PC and absorption balance can be achieved in a short time. Experimental results show that the mixture solvent possesses outstanding carbon capture capacity and is feasible to be applied in current PC washing process without any demand of equipment modification.

Abstract

The performance of heat insulation by “Smart Thermal Insulation Coating (Smart TIC)” in the combustion chamber walls were studied in a marine low speed diesel engine. Different with the adiabatic engine that features constant high temperature on combustion chamber walls and low volumetric efficiency, the Smart TIC with low heat conductivity and low heat capacity materials leads to “Temperature Swing” on the combustion chamber walls, reducing the heat transfer loss while increasing the volumetric efficiency. The simulation results show that the Smart TIC with thermal conductivity of 0.1 W/(mK), heat capacitance of 20 J/(kg*K) and thicknesses of 0.1 mm can increase the indicated thermal efficiency by 3.55% with slightly increase of NOx emissions.

Abstract

Since the deep integration and close interaction of multiple energy networks have increased the complexity of optimized scheduling of multi-energy microgrids, the present manuscript proposed a coordinated scheduling model in accordance with multiagent game theory and reinforcement learning. First, a multi-agent division was conducted. Second, a multiagent economic decision-making model and a game decision model were constructed. Thus, a coordination scheduling method was proposed in accordance with Nash game theory and the Q-learning algorithm. Finally, the efficiency and effectiveness of the proposed method were validated, which were verified by real-world case studies.

Abstract

There are certain differences in the layout of the energy systems of plug-in hybrid vehicles (PHEVs), which will result in the effects of energy management strategies. Based on the analysis of the technical characteristics of the single-motor mainstream technology routes P2, P3 and P4, this paper establishes a parallel PHEV model with different configurations based on the rule control strategy, and analyzes the impact of different configurations on the fuel economy of automobiles under the China Automotive Test Cycle (CATC).The results show that in the CD and CS stages, the P3 configuration has lower fuel consumption, and its pure electric driving range is relatively high. The P3 configuration pure electric cruising range is 0.2km and 3.1km higher than P2 and P4 respectively. This result is instructive for researchers to study the development of hybrid vehicles.

Abstract

Algeria holds one of the best solar energy resources in the world, where the most and the dominant part is located in the south of the country. Ghardaia is one of the best cities for this renewable energy resource, and it is suitable for producing other energy sources such as hydrogen through the solar parabolic concentrator. The natural gas is available in all parts of the country. However, it affects the environment. This paper is focusing on producing hydrogen from Steam Methane reforming in the city of Ghardaia through parabolic concentrator using the tracking system. Selecting CH4 as a source of hydrogen production is to minimize CO2 emission in the environment. The obtained results proofed that the amount of hydrogen produced is 0,9KgH2/m2/Day.

Abstract

In this paper, a full localization 250W@4.5K helium cryogenic refrigerator was commissioning up to nearly 470 hours. A step-by-step commissioning strategy about the stability of high and low pressure of refrigerator, cool-down processes in cold box and cooling capacity evaluation of refrigerator was carried out. Dynamic characteristics including the adjustment of pneumatic valves for the stability of high and low pressure, 300~4.5K temperature evolution of heat exchangers and turbine expanders in the cold box and cooling capacity fluctuation are experimentally discussed. The results are helpful to more precisely understand and commissioning hundred watts level helium cryogenic refrigerator.