Development of a System for Cooling Inlet Air for Gas Turbine using Fogging System

This report discusses the Development of a system for Cooling Inlet Air for Gas Turbine using Fogging system. Fogging system is one of the methods to cool inlet air for increasing the power output of gas turbines. During hot weather, power plant can produce less amount of power compared to cold condition. This is due to the decreases in air density hence less mass flow rate. The objective of this project is to study the gas turbine operating parameters when using the inlet fogging and calculating the mass flow rate of water needed to cool down the air inlet temperature near to the wet bulb temperature. Moreover, this project focuses on finding the best way to reduce the ambient temperature to the predicting compressor air inlet temperature. However, the overspray fogging or wet compression is not cover in this report. It needs some extensive studies. In this study, the temperature of air inlet is about 360 K and the air outlet is about 297 K. With the total amount of water is about 2.048 kg/s, it succeeded to cool down the airflow until 297 K. The operating parameters that used in this report were chosen based on research done through journals especially from MeeFog Industries. Then, this airflow was validated by using Computational Fluid Dynamics (CFD). This is to show the differences in air temperature during fogging process

Development of a System for Cooling Inlet Air for Gas Turbine using Fogging System

This report discusses the Development of a system for Cooling Inlet Air for Gas Turbine using Fogging system. Fogging system is one of the methods to cool inlet air for increasing the power output of gas turbines. During hot weather, power plant can produce less amount of power compared to cold condition. This is due to the decreases in air density hence less mass flow rate. The objective of this project is to study the gas turbine operating parameters when using the inlet fogging and calculating the mass flow rate of water needed to cool down the air inlet temperature near to the wet bulb temperature. Moreover, this project focuses on finding the best way to reduce the ambient temperature to the predicting compressor air inlet temperature. However, the overspray fogging or wet compression is not cover in this report. It needs some extensive studies. In this study, the temperature of air inlet is about 360 K and the air outlet is about 297 K. With the total amount of water is about 2.048 kg/s, it succeeded to cool down the airflow until 297 K. The operating parameters that used in this report were chosen based on research done through journals especially from MeeFog Industries. Then, this airflow was validated by using Computational Fluid Dynamics (CFD). This is to show the differences in air temperature during fogging process

Impact behaviour of aluminum particles upon aluminum, magnesium, and titanium substrates using high pressure and low-pressure cold spray

This study is focused on the impact and residual stress behaviour of aluminum component repair using aluminum powder via two different types of cold spray processes; high pressure cold spray (HPCS) and low-pressure cold spray (LPCS). It has been carried out via smoothed particle hydrodynamics simulations, comparing aluminum substrate with other lightweight materials such as titanium and magnesium. The obtained results have shown that the impact behaviour is influenced by velocity, porosity, deformation behaviour, flattening ratio, total energy and maximum temperature. The aluminum particles impacting on aluminum substrates using LPCS is slightly deformed, with the smallest flattening ratio leading to less pore formation between the particles. This has subsequently resulted in good coating quality. Furthermore, HPCS has contributed greatly to the deposition of particles on the heavier and harder substrate, such as titanium substrate. Thus, the overall result indicates that LPCS is better for repairing aluminum component compared to HPCS

CO2 capture for dry reforming of natural gas: Performance and process modeling of calcium carbonate looping using acid based CaCO3 sorbent

Several industrial activities often result in the emissions of greenhouse gases such as carbon dioxide and methane (a principal component of natural gas). In order to mitigate the effects of these greenhouse gases, CO2 can be captured, stored and utilized for the dry reforming of methane. Various CO2 capture techniques have been investigated in the past decades. This study investigated the performance and process modeling of CO2 capture through calcium carbonate looping (CCL) using local (Malaysia) limestone as the sorbent. The original limestone was compared with two types of oxalic acid-treated limestone, with and without aluminum oxide (Al2O3) as supporting material. The comparison was in terms of CO2 uptake capacity and performance in a fluidized bed reactor system. From the results, it was shown that the oxalic acid-treated limestone without Al2O3 had the largest surface area, highest CO2 uptake capacity and highest mass attrition resistance, compared with other sorbents. The sorbent kinetic study was used to design, using an Aspen Plus simulator, a CCL process that was integrated with a 700 MWe coal-fired power plant from Malaysia. The findings showed that, with added capital and operation costs due to the CCL process, the specific CO2 emission of the existing plant was significantly reduced from 909 to 99.7 kg/MWh

Thermal Stability of Rare Earth-PYSZ Thermal Barrier Coating with High-Resolution Transmission Electron Microscopy

Durability of a thermal barrier coating (TBC) depends strongly on the type of mixed oxide in the thermally grown oxide (TGO) of a TBC. This study aims on discovering the effect of thermal stability in the TGO area containing mixed oxides. Two different bondcoats were studied using high-resolution transmission electron microscopy: high-velocity oxygen fuel (HVOF) and air-plasma spray (APS), under isothermal and thermal cyclic tests at 1400 °C. The HVOF bondcoats were intact until 1079 cycles. In comparison, APS failed at the early stage of thermal cycling at 10 cycles. The phase transformation of topcoat from tetragonal to the undesired monoclinic was observed, leading to TBC failure. The results showed that the presence of transient aluminas found in HVOF bondcoat helps in the slow growth of α-Al2O3. In contrast, the APS bondcoat does not contain transient aluminas and transforms quickly to α-Al2O3 along with spinel and other oxides. This fast growth of mixed oxides causes stress at the interface (topcoat and TGO) and severely affects the TBC durability leading to early failure. Therefore, the mixed oxide with transient aluminas slows down the quick transformation into alpha-aluminas, which provides high thermal stability for a high TBC durability