Identification of Sound Quality Parameters With Respect to Subjective Feel of HVAC Noise of Diesel SUV’s

Author(s):  
Murali Bodla ◽  
Riyazuddin Mohammed ◽  
Rajesh Bhangale ◽  
Khumbhar Mansinh

Recent trends in developing quieter diesel power plants in automobiles leading to unmasking the secondary sound sources. One of the major secondary sound sources of in-cabin noise is HVAC system. HVAC noise is one such sound likely to be present as long as the automobile is in use. In extreme climatic conditions, like in India, HVAC is majorly operated at higher speeds and adding to that SUV volume requires more air circulation which generates lot of flow induced noise. Under these conditions, the contribution of HVAC noise is more significant for passengers and many a times it influences subjective cognition that causes the driver’s emotional response to be unpleasant, it is more important to identify the most significant sound quality parameters that contribute to the perception of HVAC noise. Measurements were done on five different diesel SUVs with different HVAC operating conditions each having variable fan speeds with engine on and off respectively. Using the semantic differential technique subjective rating of the measured signals has been done. The psycho acoustic parameters calculated objectively for the measured interior sounds later those were compared with subjective rating by using HVAC noise function (HNF) to obtain the suitable parameters to represent HVAC noise.

2020 ◽  
Vol 30 (4) ◽  
pp. 711-722
Author(s):  
Leonid L. Khoroshko ◽  
Pavel M. Kuznetsov

Introduction. The aim of the study is to develop the basic principles for digitalization of the processes of providing the diagnostics and repair of agricultural machinery. Materials and Methods. The specifics of agricultural machinery functioning are work in worst-on-worst operating conditions, such as significant abrasive contamination (soil particles, dust and other substances), operation in the conditions of exposure to natural climatic conditions, intensive use during the work shift and other factors that result in a regular need for testing and repairing. These factors significantly extend the time of maintenance and repair works. The study of the information environment for planning the distribution of agricultural machinery by repair enterprises has showed that the methods of this activity are not sufficiently developed. The authors propose a solution to the problem of rational distribution of agricultural machinery for repair and rehabilitation. Results. This article describes the main principles for developing structural relationships of databases used to find rational solutions for organizing repair and rehabilitation of agricultural machinery. Due to the fact that the solution of such a problem is time-consuming and is carried out under conditions that dynamically change over time, a mathematical model for the production environment of repair organizations is proposed, which is implemented by means of computer technology. The requirements for models describing the state of the production system of repair organizations are defined. A model of a generalized production system is proposed. Discussion and Conclusion. The model developed by the authors allows increasing the automation level of processes of distributing agricultural machinery by repair enterprises. The implementation of a new approach to planning repair works and distributing repairable agricultural machinery by repair enterprises will increase the efficiency of repair works, improve their quality parameters, reduce time, and optimize the structure of technological equipment of repair enterprises.


Author(s):  
И. Х. Саламов

Одной из актуальных задач в развитии возобновляемой энергетики является активное внедрение экологически чистых энергетических систем в частный сектор. В работе представлены результаты анализа выработки и экономической эффективности солнечной энергетической установки, работающей в частном секторе параллельно с централизованной электросетью. Исследованы методы прогнозирования выработки фотоэлектрических модулей в различных географических и климатических условиях. На основе анализа данных о выработке солнечной энергоустановки проведен сравнительный анализ расчетных и фактических характеристик в реальных эксплуатационных условиях. С использованием данных об уровне солнечной радиации на территории Чеченской Республики, а также данных о тарифах на электроэнергию в регионе, спрогнозирован экономический эффект от использования сетевой солнечной энергоустановки. One of the urgent tasks in the development of renewable energy is the active introduction of environmentally friendly energy systems in the private sector. The article presents the results of an analysis of the generation and economic efficiency of a solar power plant operating in the private sector in parallel with a centralized electric grid. Studied methods of predicting the efficiency of photovoltaic modules in different geographical and climatic conditions. Based on the analysis of data on the generation of solar power plants, a comparative analysis of the calculated and actual characteristics in real operating conditions is carried out. Using data on the level of solar radiation in the Chechen Republic, as well as data on electricity tariffs in the region, the economic effect of the use of a grid solar power plant is predicted.


TAPPI Journal ◽  
2014 ◽  
Vol 13 (8) ◽  
pp. 65-78 ◽  
Author(s):  
W.B.A. (SANDY) SHARP ◽  
W.J. JIM FREDERICK ◽  
JAMES R. KEISER ◽  
DOUGLAS L. SINGBEIL

The efficiencies of biomass-fueled power plants are much lower than those of coal-fueled plants because they restrict their exit steam temperatures to inhibit fireside corrosion of superheater tubes. However, restricting the temperature of a given mass of steam produced by a biomass boiler decreases the amount of power that can be generated from this steam in the turbine generator. This paper examines the relationship between the temperature of superheated steam produced by a boiler and the quantity of power that it can generate. The thermodynamic basis for this relationship is presented, and the value of the additional power that could be generated by operating with higher superheated steam temperatures is estimated. Calculations are presented for five plants that produce both steam and power. Two are powered by black liquor recovery boilers and three by wood-fired boilers. Steam generation parameters for these plants were supplied by industrial partners. Calculations using thermodynamics-based plant simulation software show that the value of the increased power that could be generated in these units by increasing superheated steam temperatures 100°C above current operating conditions ranges between US$2,410,000 and US$11,180,000 per year. The costs and benefits of achieving higher superheated steam conditions in an individual boiler depend on local plant conditions and the price of power. However, the magnitude of the increased power that can be generated by increasing superheated steam temperatures is so great that it appears to justify the cost of corrosion-mitigation methods such as installing corrosion-resistant materials costing far more than current superheater alloys; redesigning biomassfueled boilers to remove the superheater from the flue gas path; or adding chemicals to remove corrosive constituents from the flue gas. The most economic pathways to higher steam temperatures will very likely involve combinations of these methods. Particularly attractive approaches include installing more corrosion-resistant alloys in the hottest superheater locations, and relocating the superheater from the flue gas path to an externally-fired location or to the loop seal of a circulating fluidized bed boiler.


2019 ◽  
Vol 13 ◽  
Author(s):  
Haisheng Li ◽  
Wenping Wang ◽  
Yinghua Chen ◽  
Xinxi Zhang ◽  
Chaoyong Li

Background: The fly ash produced by coal-fired power plants is an industrial waste. The environmental pollution problems caused by fly ash have been widely of public environmental concern. As a waste of recoverable resources, it can be used in the field of building materials, agricultural fertilizers, environmental materials, new materials, etc. Unburned carbon content in fly ash has an influence on the performance of resource reuse products. Therefore, it is the key to remove unburned carbon from fly ash. As a physical method, triboelectrostatic separation technology has been widely used because of obvious advantages, such as high-efficiency, simple process, high reliability, without water resources consumption and secondary pollution. Objective: The related patents of fly ash triboelectrostatic separation had been reviewed. The structural characteristics and working principle of these patents are analyzed in detail. The results can provide some meaningful references for the improvement of separation efficiency and optimal design. Methods: Based on the comparative analysis for the latest patents related to fly ash triboelectrostatic separation, the future development is presented. Results: The patents focused on the charging efficiency and separation efficiency. Studies show that remarkable improvements have been achieved for the fly ash triboelectrostatic separation. Some patents have been used in industrial production. Conclusion: According to the current technology status, the researches related to process optimization and anti-interference ability will be beneficial to overcome the influence of operating conditions and complex environment, and meet system security requirements. The intelligent control can not only ensure the process continuity and stability, but also realize the efficient operation and management automatically. Meanwhile, the researchers should pay more attention to the resource utilization of fly ash processed by triboelectrostatic separation.


Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 226
Author(s):  
Milana Treshcheva ◽  
Irina Anikina ◽  
Vitaly Sergeev ◽  
Sergey Skulkin ◽  
Dmitry Treshchev

The percentage of heat pumps used in thermal power plants (TPPs) in the fuel and energy balance is extremely low in in most countries. One of the reasons for this is the lack of a systematic approach to selecting and justifying the circuit solutions and equipment capacity. This article aims to develop a new method of calculating the maximum capacity of heat pumps. The method proposed in the article has elements of marginal analysis. It takes into account the limitation of heat pump capacity by break-even operation at electric power market (compensation of fuel expenses, connected with electric power production). In this case, the heat pump’s maximum allowable capacity depends on the electric capacity of TPP, electricity consumption for own needs, specific consumption of conditional fuel for electricity production, a ratio of prices for energy resources, and a conversion factor of heat pump. For TPP based on combined cycle gas turbine (CCGT) CCGT-450 with prices at the Russian energy resources markets at the level of 2019, when operating with the maximum heat load, the allowable heat pump capacity will be about 50 MW, and when operating with the minimum heat load—about 200 MW.


2021 ◽  
Vol 13 (7) ◽  
pp. 3933
Author(s):  
Solomon E. Uhunamure ◽  
Karabo Shale

South Africa is been faced with erratic power supply, resulting in persistent load shedding due to ageing in most of its coal-fired power plants. Associated with generating electricity from fossil fuel are environmental consequences such as greenhouse emissions and climate change. On the other hand, the country is endowed with abundant renewable energy resources that can potentially ameliorate its energy needs. This article explores the viability of renewable energy using the strengths, weaknesses, opportunities and threats (SWOT) analysis approach on the key renewable potential in the country. The result indicates that geographic position, political and economic stability and policy implementation are some of the strengths. However, Government bureaucratic processes, level of awareness and high investment cost are some of the weaknesses. Several opportunities favour switching to renewable energy, and these include regional integration, global awareness on climate change and the continuous electricity demand. Some threats hindering the renewable energy sector in the country include land ownership, corruption and erratic climatic conditions. Some policy implications are suggested based on the findings of the study.


Author(s):  
Nikolaj Dobrzinskij ◽  
Algimantas Fedaravicius ◽  
Kestutis Pilkauskas ◽  
Egidijus Slizys

Relevance of the article is based on participation of armed forces in various operations and exercises, where reliability of machinery is one of the most important factors. Transportation of soldiers as well as completion of variety of tasks is ensured by properly functioning technical equipment. Reliability of military vehicles – armoured SISU E13TP Finnish built and HMMWV M1025 USA built were selected as the object of the article. Impact of climatic conditions on reliability of the vehicles exploited in southwestern part of the Atlantic continental forest area is researched by a case study of the vehicles exploitation under conditions of the climate of Lithuania. Reliability of military vehicles depends on a number of factors such as properties of the vehicles and external conditions of their operation. Their systems and mechanisms are influenced by a number of factors that cause different failures. Climatic conditions represent one of the factors of operating load which is directly dependent on the climate zone. Therefore, assessment of the reliability is started with the analysis of climatic factors affecting operating conditions of the vehicles. Relationship between the impact of climatic factors and failure flow of the vehicles is presented and discussed.


1998 ◽  
Vol 507 ◽  
Author(s):  
F. Blecher ◽  
K. Seibel ◽  
M. Hillebrand ◽  
M. Böhm

ABSTRACTThe series resistance limits the linearity of photodiodes and decreases the efficiency of solar cells. It is usually determined from IV-measurements for moderate and high forward current density. This method, however, provides only partial information about Rs, since the series resistance depends on the operating point. An alternative method is based on noise measurements. System noise of the measuring system with a low-noise current-voltage converter has been investigated. A new method for extraction of photodiode series resistance from noise measurements is suggested. Noise measurements are carried out for a-Si:H pin diodes. The series resistance of an amorphous pin diode has been extracted for different operating conditions using the new measurement method.


Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 247
Author(s):  
Aida Albu ◽  
Cristina-Gabriela Radu-Rusu ◽  
Ioan Mircea Pop ◽  
Gabriela Frunza ◽  
Gherasim Nacu

Romania is known among the main European honey producers, due to the variety of landforms as well as the diversity of the flora. Thirty-four honey samples of the acacia, linden and multifloral types, produced in eastern Romania and collected during 2013–2018, were physico-chemically analyzed using methods provided by the national and EU standards. The results of water-insoluble solids, color and refractive index were found to be 0.023–0.131%, 0.3–76.4 mm Pfund and 1.485–1.499, respectively. The moisture content ranged between 15.20% and 20.77%, solid substances content ranged between 79.23% and 84.80% and total soluble substances content ranged between 77.83 °Brix and 83.26 °Brix. The obtained values of specific gravity were from 1.414 to 1.450 g/cm3, pH ranged from 3.673 to 5.503 and free acidity ranged between 2.4 meq and 50 meq kg−1. The ash content and the electrical conductivity varied between 0.030 and 0.543% and 130 and 679 µS cm−1, respectively. Pearsonʹs correlation analysis showed an intense association of the ash content with electrical conductivity (r = 0.81). Our findings reveal the qualitative level of Romanian honey and the variation in quality parameters due to factors such as geographical region, climatic conditions, botanical origin and handling or storage conditions.


Author(s):  
Graeme G. King ◽  
Satish Kumar

Masdar is developing several carbon capture projects from power plants, smelters, steel works, industrial facilities and oil and gas processing plants in Abu Dhabi in a phased series of projects. Captured CO2 will be transported in a new national CO2 pipeline network with a nominal capacity of 20×106 T/y to oil reservoirs where it will be injected for reservoir management and sequestration. Design of the pipeline network considered three primary factors in the selection of wall thickness and toughness, (a) steady and transient operating conditions, (b) prevention of longitudinal ductile fractures and (c) optimization of total project owning and operating costs. The paper explains how the three factors affect wall thickness and toughness. It sets out code requirements that must be satisfied when choosing wall thickness and gives details of how to calculate toughness to prevent propagation of long ductile fracture in CO2 pipelines. It then uses cost optimization to resolve contention between the different requirements and arrive at a safe and economical pipeline design. The design work selected a design pressure of 24.5 MPa, well above the critical point for CO2 and much higher than is normally seen in conventional oil and gas pipelines. Despite its high operating pressure, the proposed network will be one of the safest pipeline systems in the world today.


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