Investigation of Dynamic Thermal Parameters of Various Insulation Filled Bricks Exposed to Periodic Thermal Variations for Energy Efficient Stuffed Bricks Design

The space cooling systems account for nearly 30% of energy consumption in India. The highly insulated external walls are essential prerequisites for low energy consumption of buildings. Filling shell of the brick with insulation material is one of the methods to reduce cooling loads in buildings. This paper aims to investigate the dynamic thermal parameters of various insulation filled bricks. The dynamic thermal parameters highlighted in the study include thermal transmittance, admittance, decrement factor, time lag and areal thermal heat capacity. The cyclic admittance method was employed in computer simulation program to compute dynamic thermal parameters of stuffed bricks. The four brick materials such as mud bricks, burnt bricks, concrete blocks and fly ash bricks were selected. The insulation materials used for filling shells of the brick are foam glass and asbestos fibre. The total forty eight stuffed bricks were investigated. The shell of the brick is filled by the insulation and the each layer of insulation is separated by a brick web. The shell and web thickness of the brick were maintained as per the Indian standards. The six configurations of the stuffed bricks were investigated (1. Solid brick, 2. Bricks with the shell of the brick filled with single layer of insulation, 3. Bricks with the shell of the brick filled with two layers of insulation with each insulation layer separated with a brick web, 4. Bricks with the shell of the brick filled with three layers of insulation with each insulation layer separated by a brick web, 5. Bricks with the shell of the brick filled with four layers of insulation with each insulation layer separated by a brick web and 6. Bricks with the shell of the brick filled with five layers of insulation with each insulation layer separated by a brick web). From the results, it is observed that the stuffed bricks significantly improve time lag values as compared to the conventional solid bricks. The decrement factor decreases, admittance increases and areal thermal heat capacity increases with the increase in the number of insulation layers in the bricks. The concrete blocks with the shell of the bricks filled with five layers of asbestos fibre insulation offer the highest admittance (3.11W/m2K), the lowest decrement factor (0.435), the highest time lag values (8.26 h) and the highest areal thermal heat capacity (57366 J/m2K) among all insulation filled bricks studied. The results of the paper help in designing energy efficient stuffed bricks which can be used for construction of buildings and thereby reducing cooling loads

Effect of Window Overhang Shade on Heat Gain of Various Single Glazing Window Glasses for Passive Cooling

AbstractThis paper presents thermal performance of various single glazing window glasses covered with and without window overhang shading. Buildings are designed with laterite stone walls with different dimensions of overhang shading devices on single glazing windows in four different climatic zones of India: Ahmedabad (Hot & dry), Bangalore (moderate), Calcutta (warm & humid) and Hyderabad (composite). In this study, five glass materials such as clear, bronze, green, grey and blue-green were selected. Total three hundred and twenty building models with and without window overhangs were designed in four climatic zones of India using Design builder 4.3.0.039. Thermal simulation was carried out in Energy plus 8.1 simulation tool. From the results, it is observed that laterite buildings with grey glass window with 1.5m overhang shading device were found to be energy efficient from the least heat gain point of view in south direction among three hundred and twenty building models studied in four climatic zones of India. The results of the study help in selecting the best window glass material and also help in selecting appropriate dimensions for overhang shading device for reducing cooling loads in buildings

Influence of injection pressure on the dual-fuel mode in CI engines fueled with blends of ethanol and tamanu biodiesel

DATA AVAILABILITY : The data used to support the findings of this study are included within the article.The acceleration of global warming is primarily attributable to nonrenewable energy sources such as conventional fossil fuels. The primary source of energy for the automobile sector is petroleum products. Petroleum fuel is depleting daily, and its use produces a significant amount of greenhouse emissions. Biofuels would be a viable alternative to petroleum fuels, but a redesign of the engine would be required for complete substitution. The use of CNG in SI engines is not new, but it has not yet been implemented in CI engines. This is due to the fuel having a greater octane rating. The sole use of CNG in a CI engine results in knocking and excessive vibration. This study utilizes CNG under dual-fuel conditions when delivered through the intake manifold. In a dual-fuel mode, compressed natural gas (CNG) is utilized as the secondary fuel and a blend of 90% tamanu methyl ester and 10% ethanol (TMEE10) is used as the primary fuel. The injection pressure (IP) of the primary fuel changes between 200 and 240 bar, while the CNG induction rate is kept constant at 0.17 kg/h. The main combustion process is governed by the injection pressure of the pilot fuel. It could be affecting factors such as the vaporization characteristics of the fuel, the homogeneity of the mixture, and the ignition delay. Originally, tamanu methyl ester (TME) and diesel were used as base fuels in the investigation. As a result of its inherent oxygen content, TME emits more NOx than diesel. The addition of 10% ethanol to TME (TMEE10) marginally reduces NOx emissions in a CI mode because of its high latent heat of vaporization characteristics. Under peak load conditions, NOx emissions of TMEE10 are 6.2% lower than those of neat TME in the CI mode. Furthermore, the experiment was conducted using TMEE10 as the primary fuel and CNG as the secondary fuel. In the dual-fuel mode, the TMEE10 blend showed higher combustion, resulting in an increase in performance and a significant decrease in emission characteristics. As a result of the CNG’s high-energy value and rapid burning rate, the brake thermal efficiency (BTE) of TMEE10 improves to 29.09% compared to 27.09% for neat TME. In the dual-fuel mode of TMEE10 with 20.2% CNG energy sharing, the greatest reduction in fuel consumption was 2.9%. TMEE10 with CNG induction emits 7.8%, 12.5%, and 15.5% less HC, CO, and smoke, respectively, than TME operation.http://www.hindawi.com/journals/ijce/am2023Mechanical and Aeronautical Engineerin

4E analysis of a two-stage refrigeration system through surrogate models based on response surface methods and hybrid grey wolf optimizer

Refrigeration systems are complex, non-linear, multi-modal, and multi-dimensional. However, traditional methods are based on a trial and error process to optimize these systems, and a global optimum operating point cannot be guaranteed. Therefore, this work aims to study a two-stage vapor compression refrigeration system (VCRS) through a novel and robust hybrid multi-objective grey wolf optimizer (HMOGWO) algorithm. The system is modeled using response surface methods (RSM) to investigate the impacts of design variables on the set responses. Firstly, the interaction between the system components and their cycle behavior is analyzed by building four surrogate models using RSM. The model fit statistics indicate that they are statistically significant and agree with the design data. Three conflicting scenarios in bi-objective optimization are built focusing on the overall system following the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Linear Programming Technique for Multidimensional Analysis of Preference (LINMAP) decision-making methods. The optimal solutions indicate that for the first to third scenarios, the exergetic efficiency (EE) and capital expenditure (CAPEX) are optimized by 33.4% and 7.5%, and the EE and operational expenditure (OPEX) are improved by 27.4% and 19.0%. The EE and global warming potential (GWP) are also optimized by 27.2% and 19.1%, where the proposed HMOGWO outperforms the MOGWO and NSGA-II. Finally, the K-means clustering technique is applied for Pareto characterization. Based on the research outcomes, the combined RSM and HMOGWO techniques have proved an excellent solution to simulate and optimize two-stage VCRS

Nano-refrigerants and nano-lubricants in refrigeration : synthesis, mechanisms, applications, and challenges

Addressing global energy security and environmental concerns, the utilization of nano-refrigerants and nano-lubricants has emerged as an innovative path for enhancing heat transfer. This research focuses on enhancing the thermophysical properties, heat transfer efficiency, and tribological characteristics of nanofluids—nanoparticles dispersed in refrigerants or lubricants. These nanofluids have demonstrated significant potential in applications such as cooling, air conditioning systems, and heat transfer equipment including pumps and pipes. A comprehensive understanding of parameters like thermal conductivity, viscosity, pressure drop, pumping power, and energy performance is delivered, with the aim of enhancing the overall efficiency of refrigeration systems, particularly the coefficient of performance (COP). Additionally, the review covers existing research on flow and pool boiling heat transfer, nano-lubricant tribological enhancement, and nano-refrigerant condensation. The study also addresses the challenges associated with the use of nano-refrigerants and nano-lubricants and offers a prospective outlook for their usage. These novel nanofluids are anticipated to emerge as effective solutions for increasing the COP and reducing energy consumption in the industrial sector, thus extending beyond the scope of previous efforts in this field. This review could serve as a valuable resource for a broad audience interested in this novel approach to energy efficiency

A novel long term solar photovoltaic power forecasting approach using LSTM with Nadam optimizer : a case study of India

Solar photovoltaic (PV) power is emerging as one of the most viable renewable energy sources. The recent enhancements in the integration of renewable energy sources into the power grid create a dire need for reliable solar power forecasting techniques. In this paper, a new long-term solar PV power forecasting approach using long short-term memory (LSTM) model with Nadam optimizer is presented. The LSTM model performs better with the time-series data as it persists information of more time steps. The experimental models are realized on a 250.25 kW installed capacity solar PV power system located at MANIT Bhopal, Madhya Pradesh, India. The proposed model is compared with two time-series models and eight neural network models using LSTM with different optimizers. The obtained results using LSTM with Nadam optimizer present a significant improvement in the forecasting accuracy of 30.56% over autoregressive integrated moving average, 47.48% over seasonal autoregressive integrated moving average, and 1.35%, 1.43%, 3.51%, 4.88%, 11.84%, 50.69%, and 58.29% over models using RMSprop, Adam, Adamax, SGD, Adagrad, Adadelta, and Ftrl optimizer, respectively. The experimental results prove that the proposed methodology is more conclusive for solar PV power forecasting and can be employed for enhanced system planning and management.https://wileyonlinelibrary.com/journal/ese3hj2023Mechanical and Aeronautical Engineerin

Assessment on performance and emission characteristics of the CRDI engine fueled with ethanol/diesel blends in addition to EGR

In this research, the CRDI engine characteristics were analyzed with the aid of exhaust gas recirculation rate (EGR) adoption fueled with ethanol blends. The test fuels were the various blends with ethanol, such as (10% of ethanol + 90% of diesel) E10D90 (20% of ethanol + 80% of diesel), E20D80, and (30% of ethanol + 70% of diesel) E30D70. From the results, it was revealed that performance characteristics were reduced when using a higher concentration of the alcohols mixed with diesel fuel. The blend E30D70 showed that brake thermal efficiency (BTE) without EGR drops by 3.8%, increased by 9.14% of BSFC, a 9.25% decrease in oxides of nitrogen emissions, and slightly decreased CO and HC emissions compared to baseline diesel operation at 60% load condition. The blend E10D90 with 20% EGR shows the highest BTE of 8.87% when compared with base fuel, due to proper fuel mixture taking place in the inlet manifold. The results indicate that the engine runs smoothly, and E30D70 has chosen an optimum blend. A further experiment was performed using E30D70 with different rates of exhaust gas recirculation system. The addition of exhaust gas recirculation with E30D70 in the common rail diesel engine exhibits oxides of nitrogen emission, but in contrast, it was noticed to have inferior performance characteristics and drastically decreased HC and CO emissions. The hydrocarbon emission decreased E10D90, E20D80, and E30D70 at 60% load condition by 21.42%, 37.38%, and 48.76%, respectively. The blends E10D90, E20D80, and E30D70 decreased carbon dioxide by 7.9%, 30.08%, and 31.98%, respectively. The maximum reduction of NOx emission was observed at about 51.06% at an EGR rate of 20% with E30D70.http://www.hindawi.com/journals/ijceam2023Mechanical and Aeronautical Engineerin

Heat transfer characteristics of fullerene and titania nanotube nanofluids under agitated quench conditions

Distilled water and aqueous fullerene nanofluids having concentrations of 0.02, 0.2, and 0.4 vol % and titania (titanium dioxide, TiO2) nanofluids of 0.0002, 0.002, and 0.02 vol % were analyzed for heat transfer characteristics. Quenching mediums were stirred at impeller speeds of 0, 500, 1,000, and 1,500 RPMs in a typical Tensi agitation system. During the quenching process, a metal probe made of ISO 9950 Inconel was used to record the temperature history. The inverse heat conduction method was used to calculate the spatial and temporal heat flux. The nanofluid rewetting properties were measured and matched to those of distilled water. The maximum mean heat flux was 3.26 MW/m2, and the quickest heat extraction was 0.2 vol % fullerene nanofluid, according to the results of the heat transfer investigation

Investigation of dual–pass inclined oscillating bed solar dryer for drying of non-parboiled paddy grains

This Paper determines an experimental study of a dual-pass solar dryer with a bed tilt of 0.5° and varying the oscillating frequency of the drying chamber namely 1.25, 1.75, and 2.25 Hz for drying an agricultural produce namely non–parboiled paddy grains. The oscillations and bed tilt are provided to move the grains from entry to exit of the top bed and move down to the bottom bed and finally exit from the dryer. The new technology has been used in the solar dryer for drying agricultural produce as non–parboiled paddy grains to increase the quality and decrease the loss of the dried produce. The present dryer model was used for drying 45 kg of non–parboiled paddy grains from 19% (w.b) to the approved range of 12–14% of moisture content obtained in a single experimental day. The dried paddy grains obtained an average moisture content are 13.03, 13.22, and 13.51% at the frequency of oscillation of 1.25, 1.75, and 2.25 Hz, respectively. The maximum thermal and pick-up efficiency of the model was obtained at 1.00 p.m. in all cases. For the frequency of oscillation of 1.25, 1.75, and 2.25 Hz, the maximum dryer thermal efficiency was 44.47, 43.39, and 41.39%, respectively, and the maximum pick–up efficiency was 80.41, 79.19, and 76.21%, respectively. The optimum drying performance was obtained at the oscillating frequency of 1.75 Hz with the bed tilt of 0.5

Developments in nanoparticles enhanced biofuels and solar energy in Malaysian perspective: a review of state of the art

The rapid rise in global oil prices, the scarcity of petroleum sources, and environmental concerns have all created severe issues. As a result of the country’s rapid expansion and financial affluence, Malaysia’s energy consumption has skyrocketed. Biodiesel and solar power are currently two of the most popular alternatives to fossil fuels in Malaysia. These two types of renewable energy sources appear to be viable options because of their abundant availability together with environmental and performance competence to highly polluting and fast depleting fossil fuels. The purpose of adopting renewable technology is to expand the nation’s accessibility to a reliable and secure power supply. The current review article investigates nonconventional energy sources added with nanosized metal particles called nanomaterials including biodiesel and solar, as well as readily available renewable energy options. Concerning the nation’s energy policy agenda, the sources of energy demand are also investigated. The article evaluates Malaysia’s existing position in renewable energy industries, such as biodiesel and solar, as well as the impact of nanomaterials. This review article discusses biodiesel production, applications, and government policies in Malaysia, as well as biodiesel consumption and recent developments in the bioenergy sector, such as biodiesel property modifications utilizing nanoparticle additions. In addition, the current review study examines the scope of solar energy, different photovoltaic concentrators, types of solar energy harvesting systems, photovoltaic electricity potential in Malaysia, and the experimental setup of solar flat plate collectors (FPC) with nanotechnology