Abstract
Process heating is an important step in manufacturing industries such as metal, cement, brick, food, etc., and accounts for a large share of the total energy consumption of those industries. ...In Nepal, process heating alone accounts for around 64% of the process energy of the manufacturing sector. Around 64% of Nepalese industries’ energy demand for process heating is supplied by high-carbon emitting fossil fuels such as coal, diesel, etc. The industrial sector is responsible for significant global greenhouse gas emissions. Nepalese manufacturing Industries emit around 0.002248 GT of CO
2
annually. The movement toward carbon neutrality has prompted many countries around the world to look for clean and sustainable fuel to meet their decarbonization goal. This study overviews Nepalese industries’ different industrial heating processes in terms of energy consumption, emissions, energy efficiency measures and interventions, and renewable options from a literature review and using data from secondary sources. Based on the data collected and the literature review of the industries, the potential low-carbon fuels which can be compatible with heating applications in Nepalese industries are reviewed. This paper concludes with recommendations for the future decarbonization of process heating in Nepalese industries.
Abstract
Most of the hydropower plants in Nepal are run-of-river type and over 60% of them are operating with Francis turbines. There are huge fluctuations in flow during the dry and wet seasons, ...which force the power plant owner to operate the turbines at off-design conditions which can induce cavitation and fatigue loads on the turbines. This study focuses on numerical analysis of a model turbine designed for the Jhimruk hydropower plant in Nepal. A geometrical modification is made to the model turbine runner blades by attaching two pairs of vortex generators (VGs) to each blade surface on the pressure side at 0.5% span, at the leading edge. The flow on the blade breaks off and separates from the surface during the off-design conditions so VGs are introduced to mitigate swirls generated at the inlet of the turbine. VGs can help to reattach the flow and improve off-design performance of the turbine. The performance of model turbine is analyzed at different guide vane openings to simulate different operating conditions by keeping the operating head constant and varying the rotational speed of the turbine from 500 to 1500 rpm. Performance curves and hill diagrams of the turbine are generated for each case with and without VGs. The results show that VGs at off-design conditions show a maximum increment in efficiency by 12% and 1 to 5% on average. The power output is also boosted by 1 to 6 kW at off-design conditions. This objective has been achieved when compared to efficiency and power at low-discharge and high-speed regions. In conclusion, VGs are simple but effective tools to enhance the performance of hydraulic turbines as well.
Abstract
The spear valve is one of the most eroded hydro-mechanical components of the Pelton turbine operating in sediment-laden conditions. The spear valve is used to regulate or control the flow. ...In a multi-nozzle system, though having the same design, the spear valves show varying erosion patterns and intensities. The only difference was found to be the openings of the nozzle/spear valve. This demonstrates that there is some sort of connection between the nozzle opening and the erosion of the spear valve. The difference in erosion intensity in different spear valves can be seen on the site but the underlying phenomenon behind the erosion needed to be studied numerically. In this research, erosion patterns were numerically investigated using an open-source CFD tool, OpenFOAM. For this simulation, the sediment particles and their properties were incorporated into the flow using the built-in Lagrangian library of the OpenFOAM. To investigate the erosion in real time, a transient simulation was undertaken for various nozzle openings. This study only focuses on the erosion at the tip of the spear valve neglecting other parts of the nozzle. This study demonstrates that the erosion in the tip of the spear valve increases with the restriction in flow.
Pumps are the mechanical device used to increase the pressure energy of fluids. Pumps of different types and size are being used in Nepal, for different applications. Despite the wide spread ...applications of pumps not much have been done to manufacture pumps in Nepal. This study investigates the opportunity of manufacturing pumps in Nepal. It shows the history of usage of pumps in Nepal and also depicts the problems faced by the pumps used in different projects. It discusses about the current market trend related to the import of pumps from foreign countries and develops an argument to start a new business for manufacturing pumps. Role of research institutes like Turbine Testing Laboratory in design of pumps has been discussed as a future prospect for Nepalese academia and industry.
Background The clinical profiles of interstitial lung diseases are reported mainly from developed world. There have been no data from Nepal. Objective The objective of this study is to describe ...clinical profile and survival in Eastern Nepal. Method Prospectively collected clinical, radiological and laboratory data of consecutive patients with Interstitial lung disease from an eastern regional tertiary care center were analyzed. The recommended official criteria for diagnosing different types of interstitial lung diseases were followed accordingly. Result The study revealed that, 68.0% of the patient's age was of above 60 years with male predominance (66.0%). Idiopathic pulmonary fibrosis (79.5%) was the commonest interstitial lung disease followed by connective tissue disease associated interstitial lung disease. Persistent cough (97.7%) and dyspnea (95.5%) were the commonest presentations. Renal impairment, ischemic Heart Disease and anasarca were significant co morbidities contributing to mortality. Survival rate of the patients was found to be maximum at 5 months (95%) and minimum at 24 months (42%) from the diagnosis of the disease. Conclusion Widespread use of High-resolution computed tomography has made early recognition of interstitial lung disease in elderly patients. Well planned large scale multicenter prospective studies are needed to broaden our understanding about this serious pulmonary disorder.
Despite the initiation of the master plan, envisioned by the government of Nepal, complete electrification of rural Nepal still seems over ambitious for quite a long time. Thus Micro Hydropower ...Plants (MHP) can still be very effective for rural electrification. Decades of manufacturing of same type turbines have saturated the turbine manufacturing industries of Nepal, which demands for some new innovations and that could be the introduction of Francis turbine in Nepalese MHP. It's undeniable that there are umpteen opportunities for the turbine manufacturers to manufacture and install the Francis turbines in Nepalese MHP. The feasibility studies performed by different institutions and the government policy strengthen the claim. In addition to that, data received from, NMHDA and a local turbine manufacturing industry suggest that there are abundant sites suitable for installation of Francis turbine. This paper illustrates the need of introducing the Francis turbine in Nepalese MHP and discusses about the opportunities available for the turbine manufacturers to enter into the market of Francis turbines for micro hydro and subsequently for larger hydropower projects in the near future. The challenges associated with the introduction of Francis turbine in MHP are highlighted.
Abstract
The national grid of Nepal faces several hurdles during its operation, especially in remote areas of hilly and mountain region. Citizens face blackouts of days to weeks, due disturbances ...caused in the grid in those regions. Micro hydro can be a very strategic backup for the national grid in those regions. However, due to lack of subsidy, which used to be provided in the past, for development of micro hydro, micro developers are unable to afford the construction cost of the micro hydro. Thus using Pumps that are readily available in the market at a much cheaper price, compared to custom built hydro turbines, as turbines can be a very economical alternative for such cases. But the concept of pump as turbine has not been utilized in Nepalese market. In this study, a centrifugal pump abundantly available in the Nepalese market has been used to evaluate its performance in turbine mode as well as in pump mode. A characteristic performance curve of the pump operated in turbine mode is obtained from the experimental data. The Best efficiency point and the operating regime is also determined based on the results obtained from experiments. The head conversion factor and discharge conversion factor calculated based on the data measured from the experiment, at various operating conditions, are compared to previous works done by other researchers. The performance obtained from the experimental analysis is comparable to the performance of the turbines installed in the micro hydro power projects. PAT can be a game changer in the micro hydro sector, by providing a very economical and technically viable option of expensive hydro turbines.
Diabetes mellitus is a non-communicable disease (NCD) with metabolic dysfunction that has attained epidemic proportions worldwide. Vascular complications account for the mortality and morbidity ...associated with diabetes. Hence, the study aimed to estimate the prevalence and risk factors for vascular complications in patients with type 2 diabetes mellitus (T2DM).
A cross-sectional national multistage survey, the Saudi Health Interview Survey (SHIS), was used in this study, which surveyed individuals aged 15 years or older. After inclusion and exclusion criteria, 1240 diabetic patients' data were analyzed for sociodemographic data, risk factors, and prevalence of micro and macrovascular complications. Binary logistic regression with stepwise backward elimination was performed to build the optimal model to assess the determinants of macrovascular complications in diabetic patients. The strength of the associations was examined by estimating adjusted odds ratios (aOR) with their 95% CI. p-value < 0.05 was considered statistically significant. R Studio Version 1.2.1093 was used for statistical analysis RESULTS: Prevalence of micro and macrovascular complications in the diabetic patients was 6.05%, in which 3.5% had myocardial infarction, 1.2% had stroke and 1.9% had renal failure. The optimal model showed that for each year increase in age (aOR=1.05, 95%CI 1.02-1.07; p-value=0.000), smoking history (aOR=4.02, 95%CI 2.23-7.26; p-value=0.000), hypertensive patients (aOR=2.71, 95%CI 1.47-4.99; p-value=0.001), patients with low physical activity (aOR=4.32, 95%CI 1.26-14.82; p-value=0.001) were more likely to develop macro and microvascular complications in diabetic patients.
The high prevalence of microvascular and macrovascular complications in diabetic patients poses a serious threat to public health in Saudi Arabia. A multisectoral approach needs to be undertaken to properly control and modify common risk factors at the community level.
A novel high-resolution planar and portable differential mobility analyzer (DMA) has been designed and built (Nano-ID® PMC500, Naneum, Canterbury, UK). Finite element multi-physics numerical modeling ...was employed to optimize the geometry of the DMA and to find a regime for high resolution within the confines of a portable instrument. The numerical approach for solving the Navier-Stokes equation was verified by comparison of calculated data to experimental values. The PMC500 was calibrated and tested with different monodisperse aerosol challenges. The PMC500 portable DMA is shown to have good sizing accuracy and resolution, similar in performance to commercially available desktop instruments.
Copyright 2014 American Association for Aerosol Research
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