bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of heat storage to properties and energy recovery of pyrolysis products from agricultural waste
Authors: Chaiwong K , Wichan N , Kuimalee S , Thawonngamyingsakul C 
Published: April 2020

Abstract
The pyrolysis process is the conversion of a biomass into biofuel but the process requires a high amount of external heat in order to increase the temperature of raw material which affects the production costs and energy efficiency. The effect of heat storage to control a temperature on the shell of pyrolysis reactor for the properties and energy recovery of pyrolysis products were considered in this study. Agricultural waste drop tube pyrolysis reactor that was designed into double layer shell wall to contain ceramic bead for heat storage. The parametric test of this study as temperature (350 °C – 550 °C), and biomass type (corncob, coffee grounds and coffee husk) were investigated. This result showed that, the heating rate of the reactor when starting to the setting temperature of the comparison testing (CT) was lower than that of the heat storage testing (HT). It indicated that the energy input for the reactor in case of HT was lower than that from CT. The yield of bio-oil and bio-char of the HT were lower than that of the CT in the same pyrolytic temperature. When increasing temperature for 350 °C to 550 °C effected to decreasing the yield of bio-char while the maximum yield of bio-oil found in the temperature of 450 °C. The heating value of pyrolysis products were increased in the higher temperature. The bio-fuel products from corncob had the higher heating value (HHV) and the energy recovery higher than that from another biomass.
Modelling and simulation of a biomass-based integrated gasification combined cycle with carbon capture: comparison between monoethanolamine and potassium carbonate
Authors: Ghiat Ikhlas , AlNouss Ahmed , Mckay Gordon , Al-Ansari Tareq 
Published: April 2020

Abstract
There are global efforts to reduce the impacts from climate change by limiting increases in temperature to 1.5 °C until 2030, and achieve carbon neutrality by 2050. Thus, it is necessary to design new neutral processes and systems that can meet the varying and growing demands of the population in terms of energy, water and food. One of the main carbon emitters and contributors to climate change is the energy industry, which primarily uses oil and natural gas as an energy source. Fortunately, alternative resources are available such as renewable energies that assemble various environmental and economic benefits. However, more work is necessitated to efficiently utilise these resources by designing, analysing, and optimising existing and new renewable energy-based processes. Therefore, this study proposes a net negative carbon emissions energy system that utilises waste biomass as a feedstock. A biomass based integrated gasification combined cycle combined with a post combustion carbon capture unit by means of chemical absorption is designed and analysed. Two different chemical solvents are used for comparison: Monoethanolamine (MEA) and potassium carbonate. The proposed integrated system is modelled and simulated in Aspen Plus software, and is analysed thermodynamically in terms of energy and exergy efficiencies. A sensitivity analysis is also conducted to assess the effect of varying operating conditions such as flowrate, and temperature of the lean solvent, and the pressure inside the stripper. At design conditions with 80% carbon capture, the system generates 419 kW of electricity and operates at -0.32 kg/kWh of CO2 for both the potassium carbonate and MEA systems.
Numerical simulation of thermal stratification and air quality in an underfloor air distribution system (UFAD)
Authors: Lopez Neil Stephen , Galeos Selena Kay , Calderon Brian Raphael , Dominguez David Roy , Uy Bryan Joseph , Iyengar Rupesh 
Published: April 2020

Abstract
The penetration of underfloor air distribution systems (UFAD) in residential and commercial air conditioning has been rather slow. The most notable applications would be on data centers, where thermal stratification requirements are more demanding. The present study supports and strengthens recent work in the design and development of UFAD systems, by augmenting literature on proper vent positioning and design. In UFAD systems where thermal stratification is more pronounced, significant energy savings may be achieved through proper positioning of supply and return vents. Using a validated numerical simulation model in ANSYS CFX, four UFAD vent layouts are investigated with regards to their implications on thermal stratification and indoor air quality. Results show that not only ventilation layout, but also vent type selection can significantly affect the performance of a UFAD system. Spreading multiple, smaller supply diffusers is preferable than having large supply diffusers on the perimeter of the rooms, both from a temperature distribution and indoor air quality perspective. Notably, air flow is significantly poor in the perimeter layout, causing warmer temperature at the center of the room.
Performance evaluation of a direct evaporative cooling system with hollow fiber-based heat exchanger
Authors: Yan Weichao , Cui Xin , Yang Xiaohu , Jin Liwen , Meng Xiangzhao 
Published: April 2020

Abstract
Direct evaporative cooling systems usually involve the process of spraying water, which may form the drift of water droplets. In addition, the use of circulating water can also lead to the growth of bacteria and molding on the surface of the packing material, affecting the indoor air quality. To address these issues, this paper intends to propose an evaporative cooling method incorporated with hollow fiber membranes. The selective permeation membrane technology allows the membrane module to isolate air from water, which selectively allows only water vapor to pass through, preventing the droplets from entraining bacteria into the air. A mathematical model has been developed to theoretically investigate the heat and moisture transfer between water and air in a hollow fiber membrane-based evaporative cooling module. The governing equations for the pre-cooling IEHX were established and then solved by employing the COMSOL Multiphysics platform. This study validated the model by comparing its outlet air dry bulb temperature and relative humidity against experimental data acquired from literature sources. The numerical model showed good agreement with the experimental findings with maximum discrepancy of 7.0%. The validated model was employed to investigate the influences of the inlet air velocity, inlet air dry-bulb temperature, inlet air relative humidity and geometric parameters on the cooling effect of the evaporative cooling module. Simulation results indicated that the outlet air temperature is greatly affected by the relative humidity of the inlet air under constant inlet air temperature conditions. A higher inlet air relative humidity will result in a higher outlet air dry bulb temperature. In addition, the cooling effectiveness was reduced for a higher inlet air velocity. The design of the hollow fiber membrane-based evaporative cooling module was optimized based on the simulation study.
Convective heat transfer study on the spiral finned tube heat exchanger under various fin pitch arrangements
Authors: Syuhada Ahmad , Afandi Dedi , Sofyan Sarwo Edhy 
Published: April 2020

Abstract
Tube-type compact heat exchangers are one of the most commonly used heat exchangers in the industry. Compact heat exchangers are known for their large surface area to volume ratios allowing more optimal heat transfer rate. This study examines both the coefficient and the rate of convective heat transfer on the outer surface of a tube-type compact heat exchanger. The heat exchanger was configured in the sharp turns and spiral fin which is varied in pitch. The Fin pitches were 1 cm, 2 cm, 3 cm, 5 cm, and 7 cm. The length of the heat exchanger pass was 30 cm with a turn length was 8.2 cm and the total length of the heat exchanger was 6 m. Heat exchangers were made using galvanized pipes with an inside diameter (Di) 20 mm and an outside diameter (Do) of 22 mm, fins are made using aluminium with a thickness of 0.3 mm. Water was maintained at a constant temperature of 80 °C and circulated into the heat exchanger with a flow rate of 0.4 L/s. The air was blown using a fan with varying speeds of 2.4 m/s, 2.8 m/s and 3.4 m/s (the ambient air temperature was 28 °C). The results showed that the highest convection heat transfer coefficient and heat transfer rate occurred in the heat exchanger with a fin pitch of 2 cm, because the turbulence was more optimal and fewer airflow losses. In the heat exchanger with a fin pitch of 3 cm, 5 cm and 7 cm has a large gap between the fins so that turbulence is not optimal while in the heat exchanger with a fin pitch of 1 cm the gap between the fins is too small so that it inhibits the rate of airflow.
Equipment load detection using deep learning for building energy management
Authors: Wei S , Tien P W , Calautit J K , Boukhanouf R , Wu Y 
Published: April 2020

Abstract
The present work will develop a learning-based approach for a demand-driven control system which can automatically adjust the Heating, Ventilation and Air Conditioning (HVAC) setpoints and supply conditions in terms of the actual requirements of the conditioned space. Internal heat gains from typical office equipment, such as computers, printers and kettle will be the focus of this paper. Due to its irregular use during scheduled heating or cooling service periods, an opportunity is offered to reduce unnecessary energy demands of HVAC systems related to the actual use of the equipment and its heat gains, i.e. over- and under-utilization of equipment indicate whether interior spaces are required to be conditioned or not. The work will be using deep learning enabled cameras which can locally run trained algorithms to analyse and take action based on how equipment is utilised in a space. This proposed strategy automatically responds to the equipment usage for optimising energy consumption and indoor conditions. The work will compare the performance of the developed approach with a conventional approach such as the use of static heating or cooling profiles. To highlight its capabilities, the approach is applied to detect the equipment usage in a real open plan office and the output (i.e. deep learning profile) is used as input for a building energy simulation model. The initial results showed that while maintaining thermal comfort levels, up to 19% reduction of the annual energy consumption can be achieved by employing the proposed strategy in comparison to conventionally-scheduled HVAC systems, while only focusing on three types of equipment.
Prediction and optimization of indoor thermal environment and energy consumption based on artificial neural network
Authors: Zhao Yan , Qian Siru , Jing Chengjun 
Published: April 2020

Abstract
Commercial software and simulation tools frequently used by researchers in predicting indoor thermal condition and energy consumption of a green building can ensure high precision, however, the computational process are usually time-consuming and cannot clearly and directly give suggestions for a ‘greener’ design. This paper aimed to develop a novel model based on artificial neural network (ANN) to speed up the simulation and provide optimal design solutions. Training and testing data representing design scenarios of different insulation thickness, shading coefficient, ventilation rate and their corresponding Annual Energy Demand (AED) and Uncomfortable Degree Hours (UDH) value were obtained from a numerical analysis model at first. The deduced ANN model was tested and validated, showing very high accuracy as a predictor for broad range of inputs. Relationship between design parameters and outputs were analysed and presented intuitively. The ANN results directly offered suggestions of minimizing AED and UDH, the optimum solution was to reduce ventilation and increase insulation to the limit, and reduce shading coefficient form base-case 0.5 to approximately 0.2. UDH could be lessened by 4% and AED could be reduced by nearly 29% compared to the base case design in this way.
Study on the influence of different surface colors on energy consumption of mall in hot summer and cold winter areas
Authors: Qian Siru , Long Enshen , Guo Shurui , Zhang Ying , Zhao Yan 
Published: April 2020

Abstract
China’s energy consumption of building operation is increasing year by year. The characteristic of building envelope is an important factor affecting energy consumption, including color and material. This paper based on the analysis of the relationship between the heat balance of the enclosure structure and the solar radiation, the micro effects of different color on the daily and hourly air conditioning energy consumption of the building are studied, and the energy saving mechanism is further divided Analysis. We found that: through the simulation calculation, the cooling load accounts for a large proportion in the hypermarket, and the number of days with cooling demand accounts for 361 days., the cooling energy consumption from May to October accounts for 100% of the total energy consumption. When the color of the coating applied on the building surface is from deep to shallow, with the increase of daily cooling consumption, the larger the number of points in the energy saving of air conditioning, the more significant the energy saving effect. The change of paint color mainly affects the energy saving rate of air conditioning when there is solar radiation in the supermarket. From the micro dimension, with the increase of solar radiation, the trend of absolute energy saving and relative energy saving effect of building air conditioning cooling load is the same.
Forced convection boiling heat transfer inside helically-coiled heat exchanger
Authors: Haryoko Luthfi A F , Kurnia Jundika C , Sasmito Agus P 
Published: April 2020

Abstract
For decades, forced convection boiling heat transfer has been considered as one of the most efficient type in the heat transfer mechanism. It has been widely utilized in heat transfer equipment of various industries. Meanwhile, helically-coiled heat exchanger has been commonly utilized in numerous industrial applications. Thus, there is an interest to utilize forced convection boiling heat transfer in helically-coiled heat exchanger. Boiling phenomenon inside helically-coiled tube is more complex as compared to the straight tube due to the secondary flow induced by centrifugal force. This study investigates flow boiling heat transfer performance of water-vapor inside helically-coiled tube by using computational fluid dynamic approach. A Eulerian-Eulerian two-fluid model is used to capture interphase exchange forces and heat transfer between liquid and vapor phase. Wall boiling model is adopted to take into account the boiling condition in the vicinity of the wall. The developed model is then validated against the previously published experimental data. Good agreement for the outlet vapor quality and pressure drop between numerical study and experimental measured value is achieved. The result reveals that the boiling starts at the inner wall of the tube (φ=450°) due to the presence of secondary flow induced by coil curvature. The relationship between HTC and vapor quality along the helically-coiled tube are discussed and evaluated. This study serves as a guideline for future study on forced convection boiling heat transfer in the helically-coiled tube.
Solar decathlon Europe 2019: The resilient nest as a solar powered and energy efficiency rooftop house for urban density
Authors: Chanto Kasan , Mahasuwanchai Peerasit , Eakintumas Warawit , Lairat Choophong , Thavornsettawat Nutkitti , Tanthanawiwat Kittipat , Wongthavornman Kunnapat , Pulngern Tawich , Chayavanich Nattavut , Wiputthanupong Wilaiwan , Pansuwan Waraluk 
Published: April 2020

Abstract
This paper presents the design concept, and monitoring results of the Resilient Nest which was participated in the Solar Decathlon Europe 2019 competition. The Resilient Nest has been designed as a lightweight rooftop house which can be placed on top of a row house in Bangkok, Thailand to respond an increased urban density. This additional rooftop house does not only increase the living space on an existing building, but it also ensures that the existing building become more viable, comfortable and eco-friendly. A solar energy, both electrical energy from photovoltaic panel and thermal energy from solar collector which are renewable energy, can accommodate the Resilient Nest rooftop as well as the existing building. The monitored results during 10 days competition results showed that the energy balance of the Resilient Nest was net positive of 171.81 kWh which was the highest value compared to other 9 competitors. The Resilient Nest generated 277.78 kWh as the first runner-up for the Energy generation. The power consumption for the HVAC system of the Resilient Nest during 10 days was only 37.65 kWh. Comparing to the suitable air conditioned house recommended by the Government Public Relations Department of Thailand, the Resilient Nest consumed over 14 times less energy because of its high performance thermal insulation, heat recovery system and solar thermal system. The low HVAC power consumption gave high performance for indoor comfort. As a result, the Resilient Nest won a second place in Comfort conditions contest.
Embodied energy and life-cycle greenhouse gas of conventional and the resilient nest house
Authors: Tanthanawiwat Kittipat , Chanto Kasan 
Published: April 2020

Abstract
This study performs the comparative assessment of the initial embodied energy and life-cycle greenhouse gas (GHG) emission between Thailand’s conventional reinforced concrete (RC) house and the Resilient Nest house which was designed and constructed for the Solar Decathlon Europe 2019 competition. The Resilient Nest is a prototype for the sustainable house and an alternative building in perspectives of renewable-energy, green building, energy efficient, and net-zero waste house. This house was designed and constructed by KMUTT team with an integration design of cosy house and the green economic system concept which have become a major concern nowadays for mitigating the environmental impacts due to an urban development. The environmental sustainability performance was investigated. All the materials used for convectional and the Resilient Nest houses as well as the energy used for the construction, were evaluated to illustrate the embodied energy (MJ) and GHG emission (kgCO2eq). As per square meter of the usable space of the house, the results show that the Resilient Nest house has embodied energy of 2,302.2 MJ/m2 and life-cycle greenhouse gas is about 122.22 kgCO2eq. Whereas, the conventional house is illustrated the consequences of embodied energy of 1,400 to 3,580 MJ/m2 and 300 – 4,625 kgCO2eq per square meter. The Resilient Nest house clearly proofs the minimizing environmental impact than the conventional house. The designation of materials was considered as an important parameter. In addition, as the whole life-cycle, the higher impact from the initial phase would be minimized and compensated during the service phase. To enhance the ultimate goal of the Resilient Nest house, recommendations for further improvement of the prototype house have been discussed.
Numerical simulation of single-sided natural ventilation: Impacts of balconies opening and depth scale on indoor environment
Authors: Izadyar Nima , Miller Wendy , Rismanchi Behzad , Garcia-Hansen Veronica 
Published: April 2020

Abstract
Heating Ventilation and Air Conditioning (HVAC), including, Mechanical ventilation (MV) in the building sector accounts for around 40% of electricity consumption and a large percentage of Greenhouse Gas (GHG) emissions. Natural ventilation (NV), as an alternative method, assist in decreasing energy consumption as well as harmful emissions. Balconies, a common architectural element in high rise residential buildings, could enhance NV and reduce reliance on mechanical ventilation in cooling dominant climates. Indoor air velocity and distribution, IAV and IAD, due to NV is less predictable than MV, and the impacts of balcony geometry on IAV and IAD profile have not yet been classified. This study, focusing on single-sided ventilation apartments, seeks to determine to what extent balcony depth and door opening area impacts on the indoor environment of the attached living area. For this, 3D – steady-state Computational Fluid Dynamics (CFD) simulations were conducted using ANSYS Fluent. The simulation results were validated against measured data in a full-scale experimental study in a residential building in subtropical Brisbane, Australia. Five different openings and nine depth scenarios were modelled, with results showing variances in indoor mean air velocity and temperature. The outcomes reveal the impacts of opening and depth scales on IAD profile, as well as IAV and temperature magnitude at the attached indoor area. Although the defined scenarios could not reach a firm conclusion, the findings of simulation reject the shallowest balcony scenario (depth less than 2 m) due to weak IAD. Besides, the results show that a small opening could lead to an acceptable IAV at the attached indoor area. Results also suggest that further research on the indoor distribution of temperature and air velocity, consequently neutrality based on thermal comfort model, may provide further clarity on the effect of geometric factors on occupant comfort through NV.
Price allocation of transmission line usage in open access system using mega volt ampere kilometer and mega volt ampere cost method for integrated Nepal power system
Authors: Acharya Prannab , Shrestha Namrata Tusuju , Mishra Brajesh , Zareipour Hamidreza , Shrestha Pramish 
Published: April 2020

Abstract
The price allocation of transmission line usage for an open access system considering Integrated Nepal Power System (INPS) has been discussed in this paper using the MVA (mega volt ampere) - KM (kilometer) and MVA cost method. The price allocation has been compared for INPS (Integrated Nepal Power System) and IEEE 14 bus system. The transmission line costs in IEEE 14 bus system is based on average construction and operation cost whereas, the costs in the INPS is an actual cost of the present transmission system. The price has been first calculated for different bus with reference to slack bus and for different bilateral and multilateral transactions, using MW KM - MW cost and MVA KM - MVA cost methods. The active and apparent powers for the base case and transaction cases have been calculated using Newton Raphson Method. The prices from MVA KM - MVA cost method are higher than MW KM - MW cost method for both bilateral transaction and multi-lateral transaction indicating more reactive power support in addition to the real power loading due to transactions in the system. The result shows that MVA KM - MVA cost method requires incentives for reactive power support to the system such as INPS.