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With the intensifying global energy crisis and environmental issues, the energy consumption and environmental impact of the construction sector have garnered significant attention. The development and application of green building materials have become crucial research areas. Traditional building materials cause substantial resource waste and environmental pollution during production, usage, and disposal. In contrast, green building materials based on thermodynamic principles, owing to their superior thermal performance and energy storage capabilities, have gradually gained attention. This paper aims to systematically optimize the thermal performance of green building materials through a research approach grounded in thermodynamic principles. The study consists of two main parts: first, constructing the control equations for the phase change thermal storage process of green building materials, and analyzing the thermodynamic characteristics during the phase change process in detail; second, conducting an in-depth analysis of the heat transfer process in phase change thermal storage green building materials to explore their thermal performance in practical applications. Despite extensive research on the thermal performance of green building materials, there are still shortcomings in the systematic analysis and optimization of material thermal performance, and existing research methods often fail to comprehensively and accurately reflect the actual thermal behavior of materials. This paper aims to provide a scientific basis for the optimized design of green building materials, further promoting their application and development in the construction field. [ABSTRACT FROM AUTHOR]

As the issues of global energy crisis and climate change are becoming increasingly prominent in the world, urban microgrids have received widespread attention as an effective way to improve energy utilization efficiency and reduce environmental pollution. Among them, the cogeneration of heat and power (CHP) system is considered as one of the key technologies to improve the energy efficiency of urban microgrids because it can provide both electricity and heat. However, how to optimize the energy flow scheduling for CHP systems, especially in the context of increasing renewable energy sources, has become a hot topic of current research. Existing studies usually rely on the traditional dualtime-scale scheduling strategies, namely day-ahead scheduling and real-time scheduling, but both have obvious limitations in dealing with the uncertainty and volatility of new energy sources. To address the above problems, this paper proposes a thermodynamic analysis-based scheduling method for optimizing the energy flow in the CHP system of urban microgrids. First, this paper introduces the concepts of rolling schedule and real-time schedule to improve the traditional time-scale scheduling method, so as to enhance the system's adaptability to new energy power fluctuations. Second, for the absorption CHP system, this paper proposes a thermal cycle performance optimization strategy, which significantly improves the utilization efficiency of thermal energy through the cascaded recycling of system waste heat. Through these two innovations, this study not only realizes a more accurate and efficient energy management, but also provides a new strategy for the sustainable development of urban microgrids. [ABSTRACT FROM AUTHOR]

With the continuous development of the Internet of Things (IoT) and new energy utilization technology, the energy management and monitoring mode has undergone fundamental changes. Design and development of remote real-time monitoring and management system for multi-energy heat collection has certain theoretical and practical application value. The existing remote temperature control model fully considers neither the impact of multi-energy collaborative heat collection on remote temperature control strategy, nor the interactions among multiple objective factors, such as climate and location. Therefore, this paper studied the remote temperature control strategy of multi-energy heat collection based on the IoT. First, the paper gave the application architecture of multi-energy heat collection system functions, and developed a multi-energy heat collection system model without simulation performance loss using stochastic modeling ideas. Second, this paper made full use of the error information of the process, thus correcting the predicted value of the remote temperature control output. Finally, the experimental results verified the effectiveness of the model and the control strategy. [ABSTRACT FROM AUTHOR]

Figuring out the action mechanism of carbon emission trend on the influencing factors of urban thermal environment from the perspective of transportation energy consumption is of great significance for transforming citizens’ means of transportation and promoting sustainable development of urban environment. However, existing studies on urban thermal environment generally focus on the quantification of urban landscape forms, the correlation analysis, or the analysis of relative importance, few of them have concerned about the action mechanism of fluid flow, heat transfer, pollutant diffusion and other process parameters on the Urban Heat Island (UHI) effect with both transportation energy consumption and carbon emission trend taken into consideration. For this reason, this paper gave the spatial structure of urban thermal environment, constructed fluid flow control equation, heat transfer control equation, pollutant diffusion control equation, and turbulence model for the urban thermal environment; then, it quantitatively analyzed the UHI intensity and air pollutant concentration, aiming to alleviate the UHI effect under the influence of transportation energy consumption and carbon emission trend. At last, this paper used experimental results to verify the effectiveness of the constructed model and gave the analysis results of thermal environment in the target city. [ABSTRACT FROM AUTHOR]

In this paper, assuming the lightweight design is the main requirement, an efficient design of honeycomb sandwich tubes and its quasi-static compressive properties improvement were presented. The structures are designed in SolidWorks software, consisting of two face sheets and a honeycomb core implemented in its in-plane position. The axial compression tests are performed using Abaqus software. Detailed deformation features and energy absorption characteristics during the crushing process were presented. The compressive properties of the improved structures were determined from the energy absorption efficiency curves. Additionally, mathematical formulas for predicting the quasi-static compressive properties are presented. Theoretical predictions and FEA findings were in good agreement. In comparison to the standard structure, the suggested method greatly increased the structure's strength without adding mass to the design. [ABSTRACT FROM AUTHOR]

This paper investigates strategies for reducing fuel consumption during the heating of steel charge before plastic processing. The study examines the impact of flue gas recuperation for combustion air preheating and the utilization of enthalpy from hot charge supplied by COS. We conducted calculations to analyze the effect of combustion air temperature and charge temperature at the furnace inlet on fuel consumption. Furthermore, an estimation of potential cost savings in heating is presented. The results of the calculations show that the use of recuperation and enthalpy of the hot charge allows for significant economic and ecological savings. These savings can range from more than 30% to more than 60% in economic terms. [ABSTRACT FROM AUTHOR]

The on-spot consumption scheme of new energy can improve the utilization efficiency of energy and provide references for the transformation from the conventional regional coal heating mode to the more efficient electric heating mode. To figure out the economic benefit brought by the new energy heating mode, it's necessary to evaluate its cost-benefit and construct reasonable model to study the dynamic market response. Therefore, this paper aims to evaluate the comprehensive cost benefit of the investment and operation of new energy heating (NEH) system and find ways to improve the said cost benefit. At first, this paper built an investment and operation model for the said NEH system, and constructed an objective function with the minimization of new energy disuse rate as the objective in the commissioned operation scheme for new energy on-spot consumption system connected with large electric heating boiler and large-capacity heat accumulator. Then, the paper gave the structure of the NEH system, and analyzed the main participants, investment and operation modes, and economic benefit of the NEH system. At last, corresponding experimental results and analysis results of an example case were given, which had verified the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

The drying and heating system (DHS) is the core component of automatic stirring equipment, so analyzing its thermodynamics is crucial for improving the efficiency of the equipment. However, existing empirical thermodynamic formulas generally take certain working conditions as prerequisites, and substituting relevant parameters of DHS into calculation can cause large errors. In view of this problem, this paper attempts to perform thermodynamic analysis and calculation on the DHS of automatic stirring equipment. At first, the material ratio of the automatic stirring equipment was analyzed in the text, and the drying and heating process of mixture was divided into three stages: mixture preheating, mixture drying, and heating mixture to the working temperature. Then, the heat consumption of DHS, the heat consumption of fuel combustion, the consumption rate of the fuel, and the heat efficiency of DHS were measured and calculated. At last, the thermodynamic analysis results of DHS of automatic stirring equipment were given, and the measurement and calculation methods adopted in the paper were proved to be effective. [ABSTRACT FROM AUTHOR]

Refrigerating machines are used in many areas to produce artificial cold. In the course of its operation, each refrigeration unit generates a lot of heat by compressing the refrigerant, which is not used in any way in the future, and during condensation is released into the environment in the form of water vapor. The use of chlorine-containing refrigerants destroys the ozone layer. To reduce environmental damage, a water reuse system was created and a technology for using low-temperature heat that is released during the operation of the refrigeration machine was developed. This paper offers various design solutions aimed at the comprehensive modernization of the cooling system of the ice palace "Puck" in Sochi to reduce its impact on the environment. In the course of the research, a refrigeration unit was developed allowing utilization, accumulation, and channeling of condensation heat for the secondary use of thermal energy by other engineering systems at the facility, thereby reducing emissions of harmful substances into the Earth's atmosphere and increasing the technological capabilities of cooling. Methods that allow making the necessary calculations and selecting equipment for the implementation of the developed systems on ice arenas are also proposed. [ABSTRACT FROM AUTHOR]

This paper presents the air breathing fuel cell (ABFC) power system and its investigation for industrial applications. The ABFC actual behaviour is realized through the development of an empirical model by considering activation polarisation, ohmic polarisation and mass transport effects. The developed stack model feeds the power conditioning unit of the proposed power system. This paper will throw light on the usage of GaN wide bandgap (WBG) material based power semiconductor devices (PSDs) that are used to build 5-level cascaded Hbridge multilevel inverter and a boost converter. This in turn enhances the energy efficiency of the entire FC power system. These WBG PSDs present the phenomenal properties such as high saturated drift velocity, wide bandgap and high critical breakdown field. This multilevel inverter is implemented for facilitating a quality AC output besides offering the voltage control. The investigation is carried out with the development of power conditioning unit hardware setup besides the fabricated FC module for the validation the developed ABFC model. [ABSTRACT FROM AUTHOR]

The energy conservation of campus buildings is the most direct and effective means to promote the sustainable development of colleges and universities. Using the heat data collected by heat supply monitoring platform to perform real-time energy consumption analysis and heating energy efficiency evaluation is a prerequisite for realizing automatic heat supply control based on energy conservation and heating demand. This paper studied the energy conservation analysis and comprehensive energy efficiency evaluation of campus central heating system based on the heat supply monitoring platform. At first, the paper elaborated on the energy consumption analysis method of the campus central heating system based on the heat supply monitoring platform; then, it gave the energy balance equation and the exergy balance equation; after that, based on a few parameters such as the EHR (electricity to heat ratio), heating index, and water makeup rate, this paper evaluated the energy efficiency of the campus central heating system, and experimental results verified the effectiveness of the analysis and evaluation methods. [ABSTRACT FROM AUTHOR]

Proton exchange membrane (PEM) is one of the most popular fuel cells for renewable energy production, and this paper presents a DC/DC boost converter structure to improve energy efficiency. To achieve high output power as well as constant output voltage, a combined method consisting of proportional-integral controller and adaptive sliding mode technique is designed. Also, due to the use of adaptive technique, the proposed technique has the ability to cover the effects of uncertainty with an unknown high limit and in addition to improving the quality of output power and voltage of PEM, it eliminates permanent tracking error and guarantees closed loop system stability. To show the operational implementation capability and flexibility of the method, FPGA has been used, which in addition to showing real-time performance, provides the ability to execute the controller at high speeds. Operationality and the possibility of practical implementation of the planned scheme on the existing systems provide the possibility of increasing the efficiency of energy extraction without further investment. The stability of the closed-loop system is achieved using Lyapunov technique and the results of simulation and comparison indicate the optimal performance of the system under the planned scheme and high efficiency in comparison with existing approaches. [ABSTRACT FROM AUTHOR]

The recent H2020 IDEAS project is oriented to the study of multi-source heat pump systems by investigating their behavior through dynamic simulations and on-field experiments in real small and large-scale prototypes respectively. One of the main aims of the project is the exploitation of available free energy sources, solar, air and ground using the heat pump technology. The key point in the investigated multi-source heat pump system is the optimal management of the renewable sources and the keeping of the ground storage available also in case of undersize of it and in case of buildings with unbalanced thermal load profile. In the last year of the project the algorithm for the control of sources and devices in the IDEAS system has been developed to maximize the use of renewable energies and at the same time to minimize the consumption of auxiliary energy. The present paper shows the details of this part of the project highlighting limits, potential and properties of the management system with a discussion of the results obtained from the onfield experiments. In the last part of the project, the implementation of weather forecast and artificial intelligence in the algorithm is planned. [ABSTRACT FROM AUTHOR]

Today waste heat recovery of air conditioning is receiving considerable attention worldwide. This paper reports investigation on the development of a stand-alone thermoelectric power generator (STEG) using heat of refrigerant leaving the condenser and self-cooled by condensate of a split-type air conditioning. The STEG is composed of a small hollowed aluminum block integrated in the hot refrigerant line leaving the condenser to collect and transfer heat to the hot side of two thermoelectric (TE) modules 40 x 40 mm installed on the right and left. To cool the TE modules, water condensate circulates by gravity inside two aluminum alloy blocks. Tests were conducted using 2-tons split-type air conditioner installed in a 64 m3 room of a residential house in Bangkok. Electrical current generated by the two TE modules was recorded separately and connected in series three times for each case. Experimental results showed that STEG can produce electrical current continuously and varied depending on the operation on the compressor. The more important the cooling, the higher is the voltage produced. The maximum recorded voltage is about 200-250 mV by each TE module and doubled with the TE modules connected in series. The average water condensate flowrate was 11.56 g/min. The average coefficient of performance (COP) and the average Energy Efficiency Ratio (EER) of the air conditioning with STEG were 1.87-1.88 and 6.38-6.42 respectively, 3% higher than those of the conventional system. [ABSTRACT FROM AUTHOR]

Needless to say, green buildings have now become an inevitable trend for the sustainable development of society, and they have paved a way for the harmonious coexistence between man and nature. The design of building facade is an important part in green building construction, to achieve the optimal energy-saving effect of building facade, scholars in the field have attached great importance to this aspect and they have done works to optimize it from constituent materials, structural forms, and thermal insulation properties, etc. For the same purpose, this paper proposed a new method for the energy efficiency design of building facade and a thermodynamic evaluation method. First, the paper analyzed the factors that can affect the energy efficiency design of the wall, windows and roof of building facade; then it gave the calculation methods of parameters that are related to the energy-saving performance of building facade such as the coefficient of building shape (CBS), resistance of heat transfer, and thermal inertia (TI); after that, the paper summarized tips for the energy efficiency design of building facade, put forward a thermodynamic evaluation method for assessing the energy-saving efficiency and economic efficiency of green building facade based on the life cycle theory, and it elaborated the calculation process of energy consumption, exergy consumption and total cost of each stage in the life cycle of the building facade; at last, the paper verified the effectiveness of the new design method and the proposed evaluation method with experimental results, and the research findings of this paper can be applied to the design and evaluation of other buildings. [ABSTRACT FROM AUTHOR]

Thermodynamic energy method can analyze the concrete failure, and crack emergence and propagation under hydraulic fracturing in engineering practice objectively and reasonably. The cracking of hydraulically split concrete absorbs and consumes energy, under the action of external hydraulic force and external load. The entire cracking process obeys the thermodynamic principles of energy conversion and conservation, and the principle of energy superposition. Following the thermodynamic principle of minimum energy consumption rate, this paper explores the emergence and propagation laws of concrete cracks under hydraulic fracturing. The hydraulic fracturing is essentially an energy dissipation process involving concrete failure, and crack emergence and propagation. The crack tip must feature the minimum energy consumption rate. On this basis, we proposed a new research approach for crack emergence and propagation, under the thermodynamic principle of minimum energy consumption rate. Next, we established a model for the concrete failure, and crack emergence and propagation under hydraulic fracturing. The research sheds new light on solving the dynamic hydraulic fracturing cracks induced by seismic load, and provides a reference for the seismic evaluation of super-high arch dam. [ABSTRACT FROM AUTHOR]

The heat metering of heating is a main link in energy conservation of ventilating airconditioning (VAC) heating. It is of great practical significance to study the heat metering of heating. However, not many scholars have estimated the heat index based on building heating area, in the light of thermal comfort. Therefore, this paper estimates the heat index of VAC heating area considering thermal comfort. Firstly, we analyzed the various factors affecting human thermal comfort. Then, four environmental factors were selected, namely, indoor air temperature, relative air humidity, mean radiation temperature of envelope surface on human body, and indoor vertical air error. In addition, we selected suitable thermal comfort indices to predict and assess the thermal environment under indoor VAC heating. After that, we analyzed the indoor heat flow under VAC heating, examined the components of energy consumption of indoor VAC heating, and estimated the heat index of VAC heating area. Next, a mathematical model was constructed for heat metering, according to the heat consumption of the building VAC, and the composition of the heat consumption of occupants. Experimental results verify the effectiveness of the proposed thermal metering model. [ABSTRACT FROM AUTHOR]

In automobiles, the demand for HVAC has been rising for decades and the key variables that affect the thermal comfort in a car were identified as air velocity, temperature, radiant temperature, and relative humidity. Thermal comfort estimation in a vehicle depends on the transient behavior of the cabin space and boundaries. The predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) are the available methods to describe and optimize thermal comfort in cabin space. In this paper, the cabin thermal comfort of a minivan was analyzed for reduction of energy consumption with the help of experimental and numerical simulation. Using CFD simulation and validation with experimental data, the flow dynamics inside a vehicle cabin is evaluated based on air velocity, temperature, and comfort indices. With some error for the extreme planes, a strong agreement was reached between the experimental values and the CFD model. With the reduction in the air velocity from 2.3 m/s to 1.3 m/s, the average power required to run the blower can be reduced by 43%, providing an advantage of reducing the capacity of the compressor. The higher PPD values were observed on the walls of the cabin and at the outlet of the AC vents. [ABSTRACT FROM AUTHOR]

Proton-exchange membrane (PEM) is one of the most common fuel cells for renewable energy generation. In this paper, the structure of DC/DC boost converter is presented to improve the energy efficiency and the combination of proportionalintegral controller with adaptive sliding mode method is designed to achieve high output power as well as constant output voltage. The proposed method has the ability to cover uncertainty effects with an unknown upper bound due to the use of adaptive technique and in addition to improving the quality of output power and voltage of the PEM, also eliminates permanent tracking error and ensures the stability of the closed loop system. The stability of the closed-loop system has been obtained using Lyapunov method and the simulation and comparison results in MATLAB environment show the optimal performance of the system under the proposed method and high efficiency compared to the existing methods. [ABSTRACT FROM AUTHOR]

Desiccant is a hygroscopic substance generally used in the dryer and air-conditioning system as a drying agent. The function of desiccant is to remove moisture from the air to reduce the humidity of the surrounding air been conditioned. This paper presents several works on the performance of desiccant material in the drying and air-conditioning application. It puts focus on the various advantages and disadvantages of the use of desiccant as a drying agent. There are some advantages of using desiccant include consistent drying and low energy usage. However, there are several disadvantages of using desiccants which are low capacity for moisture absorption and pressure drop in solid desiccant. Solar drying applications have some advantages such as being comparatively cheaper than other methods and less risk of spoiling the product. On the contrary, drying applications have disadvantages include being lower in comparison to the original foodstuff and drying foods eventually leads to shrinkage. The advantages of using desiccant in air-conditioning applications offer dehumidified fresh air to keep the building's temperature in a comfortable range and enhances water recovery efficiency. There are disadvantages such as desiccant will substantially impact the system's performance and desiccant should be cooled after completely dried. [ABSTRACT FROM AUTHOR]

The HVAC (heating, ventilation, and air conditioning) systems utilization has increased in the last decade. It conducts global warming which has an impact on the rising of global temperatures. An excellent air conditioning system will make the room comfortable conditions. This paper aims to investigate the mosque space with a cooling model of wallmounted air conditioning and the difference in inlet angle and air inlet velocity. The room design was constructed using SolidWorks software. Air distribution observations were created using ANSYS Workbench simulation software. The use of a supply angle of 90° results in an even distribution of air with a low inlet velocity, whereas in conditions of a supply angle of 60° requires a higher inlet speed. Thus, the uniform air distribution is able to be realized by the proper configuration which results an appropriately room temperature and saves energy usage. [ABSTRACT FROM AUTHOR]

Penetration of renewable energy systems (RES) into microgrid (MG) increases rapidly due to the intensified energy demands by the distribution level consumers. To meet this demand, consumers are erecting small scale distribution renewable energy generating systems (DREGS) which mostly constitutes of solar photovoltaic systems. Injecting power from the DREGS to the MG will rise potential problems like real and reactive power distortions, sag/swells which affect the power quality of the system. Voltage sags and swells are normally caused by MG intermittencies which occur at the high power and low energy situations. In order to maintain the power quality of the MG during intermittencies, an ultracapacitor (UC) is integrated along with a unified power quality conditioner (UPQC) with the DREGS is proposed in this paper. Basically, an ultracapacitor is a high power and low energy density device that will compensate the MG intermittencies. This proposed system deals with the control and design aspects of the ultracapacitor, a bidirectional converter for charging and discharging of UC, and a UPQC. The UPQC will act as a dynamic voltage restorer (DVR) for the MG side and an active power filter (APF) for the load side. The proposed system is designed and modelled using Matlab/Simulink platform and the results were analyzed. [ABSTRACT FROM AUTHOR]

In summer, the utilization of solar energy can possibly satisfy the water demand. This paper examines the fluid flow in solar pump systems with solar cells. Specifically, a solar pump system model was designed and subjected to an installation test. The model consists of two solar cell units connected in series, which generate electricity and flow into the pump system. By the principles of fluid mechanics, the test results were analyzed to optimize the pump efficiency. The analysis shows that the solar cell efficiency is influenced by solar intensity, while the pump loss is maximized by fluid friction. In addition, pressure increase could affect the time of water filling; the voltage and current tend to be stable or constant. [ABSTRACT FROM AUTHOR]

At this critical junction of industrialization, China is facing an increasingly prominent imbalance between energy supply and demand. It is of great social significance to study the energy-saving of buildings that consume a huge amount of energy. For most heating systems, energy waste mainly arises from inefficient operations of boilers, low efficiency of pipe transmission, and poor quality of heat supply. This paper researches and evaluates the energy-saving reconstruction of intelligent community heating (ICH) system based on the Internet of things (IoT). Firstly, the energy-saving reconstruction of the ICH system was analyzed, and a hydraulic regime model was derived from the simplified model of the water supply and return pipe networks. Then, the system pipe network was investigated in three aspects, namely, node flow balance, pipeline pressure drop balance, and loop pressure drop balance. On this basis, the authors presented the balance equation and finalized the hydraulic regime model of the system. After that, the energy consumption of the system was evaluated before and after the reconstruction, and the energy-saving benefit was predicted. The effectiveness of the proposed method was proved through experiments. [ABSTRACT FROM AUTHOR]

The global warming and soaring energy consumption have motivated many scholars and policymakers to pursue energy conservation and environmental improvement. As a renewable cleaning energy, geothermal resources have been actively developed in recent years. Taking six geothermal projects in Hunan, China as examples, this paper determines the input and output indices for each project. The input indices cover both economic and environmental dimensions. Then, the authors deeply explored how much geothermal resource quantity, single-well yield, total investment, and annual cost investment influence dynamic investment recovery period, coal reduction of summer operation, coal reduction of winter operation, environmental protection and energy saving, standard coal reduction, and emission reduction. The results show that total investment, single-well yield, and total investment have significant effects on economic indices, while geothermal resource quantity, single-well yield, and total investment have significant effects on environmental indices. [ABSTRACT FROM AUTHOR]

Biomass energy is one of the most important renewable energy sources. Full utilization of this energy helps to optimize agricultural development, improve our living environment, and replace some non-renewable energy sources, thereby promoting the eco-environment across the country. However, biomass energy has not been extensively utilized in rural areas of China. Many farmers are not very enthusiastic about the use of biomass energy. Many scholars have tried to boost the willingness of farmers to utilize biomass energy. Therefore, this paper collects the relevant data from six aspects, namely, environmental factor, cost factor, income factor, behavior factor, policy factor, and personal factor, and constructs a binary logistic regression model. On this basis, the driving and influencing factors of biomass energy utilization were empirically analyzed from the perspective of farmers. The results show that the development of biomass energy is mainly affected by the farmers' awareness of national energy strategy, the relevant costs of biomass utilization, and the attitude of family members and village committee. The research provides an important reference for further promotion of biomass energy, elevation of its utilization efficiency, and optimization of energy structure in rural China. [ABSTRACT FROM AUTHOR]

For tourism industry, the ever-increasing energy consumption and the high carbon emissions are requiring close attention and prompt solution, thusly endowing the research on the energy-saving of buildings in tourist resorts very important and practical significance. For this reason, this study carefully considered the actual situations such the energy utilization method and the hygrothermal environment of tourist resorts and constructed a hygrothermal transfer model and the corresponding hygrothermal balance equation for buildings in tourist resorts; then, the paper proposed a few effective strategies for the energy-saving management of buildings in tourist resorts, and studied the annual energy consumption of tourist resorts and gave a building energy consumption analysis. At last, experimental results verified the rationality and effectiveness of the proposed energy consumption assessment and energy-saving management methods for tourist resort buildings in hygrothermal environment. This study provided a useful reference for the energy-saving methods of buildings in tourist resorts. [ABSTRACT FROM AUTHOR]

The productivity of coalbed methane (CBM) depends heavily on the heat environment, and directly reflects the quality of the well. Following the theories of phase space reconstruction and Bayesian evidence framework, this paper puts forward a Bayes-least squares-support vector machine (Bayes-LS-SVM) model for the prediction of energy-efficient productivity of CBM under Bayesian evidence network based on chaotic time series. The energy-efficient productivity stands for the gas and water production of CBM wells at a low energy consumption, despite the disturbance from the heat environment. The proposed model avoids the local optimum trap of backpropagation neural network (BPNN), and overcomes the main defects of the SVM: high time consumption of parameter determination, and proneness to overfitting. In our model, the model parameters are optimized through three-layer Bayesian evidence inference, and the input vector for prediction is selected adaptively. In this way, the model construction is not too empirical, and the constructed model is highly adaptive. Then, the theory on phase space reconstruction was applied to investigate the chaotic property of the time series on CBM production, and the Bayes-LS-SVM was adopted to predict the time series after phase space reconstruction, in comparison with neural network prediction methods like SVM and BPNN. Experimental results show that the proposed model boast quick computing, accurate fitting, flexible structure, and strong generalization ability. [ABSTRACT FROM AUTHOR]

In this paper, the effect of the form and the shape of the exhibition on the performance of the absorption of solar energy in both cold & mountainous and hot & dry climates has been investigated. The form as the most prominent design feature in buildings has a significant impact on energy efficiency and can be expressed in different ways in a building. In order to evaluate the energy performance of various geometries as an exhibition, the absorption of solar energy in several geometries with different shapes, such as: hexagonal / pyramid / prism / incomplete prism / rectangular cube / cube / hemisphere / cylinder / cylinder combination and the rectangle cube combination, have been numerically simulated. For all geometries, the total area and other simulation conditions are assumed to be the same. The results show that in both types of climate, the most absorbed solar energy is obtained for pyramidal geometry and the least absorption is obtained by hemispherical geometry. The hemisphere form in the hot and dry climate has the best form-to-type ratio in order to provide thermal comfort and reduce energy consumption during the exhibition. In the cold and mountainous climate, pyramidal geometry has the highest energy absorption and is the best option among all investigated geometries. The absorption of solar energy in hemispherical geometry for hot & dry and cold & mountain climate is 66% and 54% compared to pyramidal, respectively. [ABSTRACT FROM AUTHOR]

During pipe jacking in unstable coal rock formation, it is difficult to ensure the stability of the workface and the structural safety of the equipment. To solve the problem, this paper establishes a numerical model for the rock-breaking and slag discharge of pipe jacking machine (PJM) with different tunneling parameters, and numerically analyzes the variations in the flow rate and speed of slags, and the stress and deformation of cutterhead, at different cutterhead speeds (1.0-4.0r/min) and jacking speeds (0.5-4.0mm/s). Based on the simulation results, the authors discussed how different tunneling parameters affect the tunneling safety. The simulation results highlight the importance of the matching between cutterhead speed and jacking speed to tunneling safety. As the jacking speed increased, the load of the cutterhead increased significantly, which may cause the cutter to wear. At the jacking speed of 4.0mm/s, the equivalent stress and deformation of cutterhead peaked at 397.43MPa, and 10.73mm, respectively. Excessive jacking speed may result in accidents, such as deformation and structural fracture of cutterhead, posing a serious threat to the structural safety of cutterhead. As the cutterhead speed increased from 1.0r/min to 4.0r/min, the mean axial speed of slags dropped by 68%, and the slag flow rate declined by 76%, due to the rapid discharge of slags from the cabin. In this case, the slag volume in the cabin cannot provide sufficient support to the workface rock, and the risk of collapse soars during the tunneling in unstable formation. In addition, an excessive cutterhead speed increased tunneling energy consumption and aggravated the wear of the cutterhead. The research results promote the setting of control parameters for the safe pipe jacking in unstable coal rock formation. [ABSTRACT FROM AUTHOR]

Population growth and urbanisation have resulted in exploitation of natural resources, anomalous climate change and environmental pollution. Thus, there is a need for the development of new construction techniques that will not only ensure the preservation of natural resources but at the same time will focus in making a building that is energy efficient and environment friendly. Light transmitting concrete aims to meet such requirement which helps in bringing the minimisation of artificial energy usage by directly allowing the sunlight to project through a concrete material. This paper deals with the study of mechanical and optical properties of light transmitting concrete produced by the inclusion of 2mm diameter plastic optical fiber with four different densities in a concrete cube of dimension 150mmx150mmx150mm. The experimental results show that mechanical strength of concrete mixes containing plastic optical fiber (7x7) increases by 15.057% with light transmission intensity of 69lux greater than conventional concrete at 28 day age. Study also focused on evaluation of Rebound Hammer test results for concrete incorporated with Plastic Optical Fiber. Moreover, the stress-strain relationship showing actual behaviour of fiber concrete under compression is highlight in study. Based on the results it is concluded that the presence of plastic optical fiber in concrete material does not impair its mechanical properties and it represents a new way to harness the sun's energy because of its excellent light transmission capacity. [ABSTRACT FROM AUTHOR]

Petroleum, oil and lubricants (POL) is critical to the functioning of oil equipment. It is very important to maintain the quality of POL consumption data of oil equipment. High-quality POL consumption data provide reliable datasets for computing the annual POL supply quota of oil equipment and improving the energy efficiency of such equipment. Based on the data analysis platform SPSS, this paper designs a hybrid quality control strategy called SEIB-K for POL consumption data of oil equipment, which couples the expectation-maximization algorithm with multiple imputations (EI), box plot (B), and kappa coefficient (K). The SEIB-K can systematically analyze the quality of actual POL consumption data, identify the missing items, abnormal items and contradictory items. Example analysis shows that our strategy could significantly improve the quality of POL consumption data. The research results provide a technical support for accurately determining the annual POL supply quota of oil equipment. [ABSTRACT FROM AUTHOR]

This paper aims to optimize the vent design for additional sunspace of passive houses in rural areas. First, a typical rural house in northern China's Hebei was selected as the research object. Then, a total of twelve models with different vent length and vent number were designed to allow the warm air move from the sunspace to the house. All the vents are assumed to be square in shape and manually controllable according to the sunspace temperature. Through Fluent simulation, the twelve models were compared based on different variables, and the models with the best and worst results were determined. The results show that the addition of vents facilitates the exchange between the warm air in the sunspace and the cool indoor air, improving the warming speed and efficiency indoor; the highest indoor temperature was achieved at the vent length of 0.3m, using three inlet vents and two outlet vents. On this basis, the best and worst performing models were further compared to identify the influencing factors of sunspace and optimize the vent design. The energy-saving, emission reduction, and environmental impacts of the vent design were also discussed. The research results lay a theoretical basis for reducing the energy consumption of winter heating in rural houses, and promoting the sunspace design of passive houses. [ABSTRACT FROM AUTHOR]

Geothermal energy is a clean and renewable energy. If developed and utilized efficiently, the geothermal energy would contribute greatly to the sustainable development of the energy industry. To improve the efficiency and economy of geothermal utilization, this paper examines the mechanism of the structural upgrading and industrial innovation of the energy structure, based on the existing methods of the energy industry. Next, an economic model was established for geothermal energy consumption, and optimized through mathematical analysis, in the light of the factors affecting the sustainable energy development. The research results show that: the mining and utilization of geothermal energy are influenced by climate, geology and mining method; our economic model for geothermal energy consumption considers the construction cost under multiple energy utilization scenarios; the optimized economic model for geothermal energy consumption can enhance the energy efficiency, and promote the economic and social benefits of geothermal energy industry. This research lays the theoretical basis for sustainable development energy, the coordinated development between energy and environment, and the mining and utilization of geothermal energy and other clean and renewable energies. [ABSTRACT FROM AUTHOR]

The next generation of light duty Diesel engines will face increasingly stringent emissions regulations, as well as the restrictions enforced by some local administrations. As a result, many manufacturers are starting to abandon this technology, because of the high costs and the reduced appeal on customers. On the other hand, Spark Ignition (SI) engines are not able to match the thermal efficiency of diesels, as well as their low emission of carbon dioxide (CO2): therefore, it would be highly desirable to identify cost effective solutions that permit to overcome the limits of Diesel engines, in particular soot emissions, while maintaining all the above-mentioned advantages. Dual fuel combustion, combining Natural Gas and Diesel fuel, is a well-proven technique for reducing soot emissions, while maintaining, or even increasing fuel efficiency. Moreover, this technology can be directly applied to existent Diesel engines with a few hardware modifications. However, to achieve the best results, a brand new calibration of the engine control parameters is needed. CFD-3D combustion simulation is the most cost effective tool to drive the experimental calibration process. Obviously, the numerical models must be previously calibrated against a first set of experimental data. The first part of this study, based on a previous work [9], reviews the building and experimental validation of a CFD 3D model, able to analyze this type of Dual Fuel concept applied to a current production light duty turbocharged Diesel engine, suitable for many different applications. A good agreement between simulation and experiments is found. In the second part of the paper, the calibrated model is used to investigate Dual Fuel combustion, analyzing the effects of Diesel oil injection strategies. [ABSTRACT FROM AUTHOR]

With the deepening of industrialization, energy resources are of strategic importance to China, as they lay the foundation for social and economic development. The energy consumption pushes up the economic cost of the industry, but the enterprises can obtain lots of benefits by utilizing the residual heat. This paper adopts the thermoeconomic cost analysis model, which examines economic factors through thermodynamic analysis, to disclose the relationship between energy consumption and economic growth in China. In addition, the energy consumption was optimized through a case study on iron and steel enterprises, in light of thermoeconomics. The results show that China's economic growth has linear and nonlinear dynamic correlations with the total energy consumption, coal consumption and oil consumption; the total energy consumption grows at a slower rate than economy, and the energy consumption rate exhibits a declining trend; residual heat recovery and utilization can greatly reduce the level and rate of energy consumption, and enhance the output energy value, thus lowering the thermoeconomic cost. The research findings lay the theoretical basis for the application of thermoeconomic cost in energy consumption analysis. [ABSTRACT FROM AUTHOR]

The present work proposes an analytical investigation on the energetic and exergetic performance of an air heating solar collector having absorber surface equipped with fins and twisted tapes of twist ratio Y=2,4,6 and 8. A mathematical model capable of predicting the energy and exergy efficiency has been developed. The effects of mass flow rate, twist ratio and insolation on the thermal and exergy efficiency have been studied. Further, a comparison has been made with the results of smooth absorber solar air heater to check the performance enhancement over it. The results indicated that the thermal efficiency increases monotonically with increase in air flow rate but the exergy efficiency curve first goes up, achieves its maxima and then declines. Decrease in twist ratio from Y=8 to 2 leads to improvement in the thermal efficiency for whole range of studied mass flow rate but enhancement in the exergy efficiency was observed only up to the mass flow rate of 0.022 kg/s thereafter it starts decreasing. [ABSTRACT FROM AUTHOR]

Rural household energy consumption is an important component of national energy consumption and plays a vital role in rural economic and ecological environment development. In this paper, the energy consumption of 1126 households in four typical agricultural provinces was investigated. In addition, multilayer perceptron neural network is adopted to conduct variables selection. Moreover, Logit, Tobit and multiple regression models are used to reveal the impact of different factors on rural resident choice and quantity behavior. The results show that family size, market distance, education level, farmland area and occupation affect farmers' energy choices and quantity consumption behavior to varying degrees. The differences of energy availability and convenience caused by the difference of geographical features are important factors that affect the energy consumption behavior of farmers. Income level is a key determinant of transition of energy consumption behavior, which however is not sensitive to coal. We hold the opinion that the key to improve rural energy structure in China is to boost the income level of rural residents. Meanwhile, rural energy consumption should be included in the national energy strategy framework. The government should increase the investment on the research and implementation of the renewable energy and use economic measures such as taxes and subsidies to reduce initial installed costs and operating costs so as to speed up the of upgrading rural energy consumption structure. [ABSTRACT FROM AUTHOR]

In recent years, green libraries are springing up in many Chinese universities. The green library is an energy-efficient type of library that provides an excellent reading environment. The library's energy efficiency relies on the careful design of natural and artificial lighting, illumination uniformity as well as heating efficiency. Therefore, this paper attempts to laid down an energy-efficient design to make the Hebei Agricultural University Library a green library. Specifically, the comprehensive energy consumption of the reading space was evaluated through dynamic and static simulations of illumination variation, illumination uniformity, daylighting factor and supplementary lighting under different windowing conditions. The evaluation results were coupled with the enclosure energy consumption to determine the optimal energy consumption plan. From this case study, it is found that the window area in the south-facing reading space is beneficial to the energy efficiency of the whole library. Thus, the south-facing window area should be increased as much as possible. [ABSTRACT FROM AUTHOR]

This paper aims to disclose the correlation between orientation and energy consumption of semi-underground ski slope (SUSS) in hot summer and cold winter region. For this purpose, the Design Builder software was adopted to simulate the energy consumption of a typical SUSS in the target region at different orientations. Through quantitative and qualitative analysis, it is concluded that the SUSS consumes more energy in summer than in winter; the energy consumption reaches the minimum at the azimuth of 300' and the maximum at 120'. The research findings lay a theoretical basis for the design standard and regulation of the SUSS and shed new light on the energy-saving design of buildings. [ABSTRACT FROM AUTHOR]

The availability of reliable and up-to-date data on energy uses and consumption is a key aspect in order to achieve the goals set out by European Directives on energy efficiency, and to monitor the effectiveness of energy policies supporting buildings' retrofit actions. In such a context, a numerical model, implemented in Excel' and Matlab', was developed in order to determine the energy consumption for space heating, domestic hot water and cooking in households, based on a statistical dataset of 20,000 records collected in a survey on the energy consumption of Italian families carried out by the National Institute of Statistics (ISTAT). The space heating model is based on the definition of classes of dwelling-types, while the energy use for DHW and cooking are calculated on a record-by-record basis according to a Standard-based approach. The present paper presents the results of a refined version of the model, in particular the calibration of relevant parameters accounted for the secondary equipment for space heating, resulting in improvements in the reliability for the allocation of the fuel consumption among the end-uses. The refinement and validation of the model are still in progress, since they are functional for the assessment of the energy consumption of households in the period between two subsequent surveys. [ABSTRACT FROM AUTHOR]

Glass window enclosures for buildings consume a lot of energy for affording thermal and visual comfort. Reducing solar radiation in summer and increase in winter through different double window glasses for making energy efficient building design is the theme of this paper. Therefore this work measures the spectral characteristics of four glasses namely grey, green, bronze and clear glasses in entire solar spectrum region from 300nm to 2500nm at normal angle of incidence by using Shimadzu UV 3600 spectrophotometer based on ASTM standards. To find the solar optical properties a MATLAB code was used which is based on British standards. To find the solar radiation transmission from different double window glass configurations and cost analysis from eight coordinal directions at peak summer and winter day were selected as per Indian standards with a MATLAB code to hot and dry climatic zone of Jodhpur (26.300N, 73.020E). From these results it is shows that in south direction all double glass windows are gaining less heat in summer and more heat in winter season when compared to other orientations. It is found that south orientation C1(Greyglasswindow-Airgap10mm- Greenglasswindow) and C12(Clearglasswindow-Airgap10mm-Bronzeglasswindow) configuration windows are gaining minimum and maximum heat in summer and winter respectively when compared to other configuration windows. Among all windows C1 configuration window is saving more cost annually. [ABSTRACT FROM AUTHOR]

The use of special kind of arrangement absorber plate is an effective and economic method to improve the thermal performance of a solar air heater. In this paper, the thermal performance of a solar air heater was experimentally investigated with different absorber plates with a mass flow rate of 20 kg/h and 25 kg/h with different arrangements of absorber plates such as glass plates and galvanized iron (GI) sheet varying mass flow rates of air. It was observed that thermal efficiency was increased by 9.4% while using the glass plate absorber compared to the galvanized iron (GI) sheet absorber plate. [ABSTRACT FROM AUTHOR]

Based on the unified physical model and mathematical model of the heat economic analysis of thermal power generating units, this paper employs the partial differential theory and gradient operator to construct a calculation model for the strength coefficient of the effect of main steam pressure variation on the economical efficiency of the unit. Under each working condition, the strength coefficient greatly reduced the main steam pressure on the impact of change on the unit coal consumption rate calculation workload. A case study on the typical working condition of a 600MW unit reveals that the proposed model for the strength coefficient boasts a small computational load and high accuracy when it is applied to calculate the effect of main steam pressure variation on the coal consumption rate. Moreover, the concept of a strength coefficient provides a new way of energy saving for the thermal power generating unit and the quantitative analysis of a thermal system. [ABSTRACT FROM AUTHOR]

The residential sector has been achieved in the last years more and more importance in the total energy consumption scenario by stimulating the research for solutions to promote energy efficiency and to raise awareness on energy consumption by end user. The profile of an end-users energy consumption assumes a central role in finding solutions to reduce energy demand and increase the efficiency in the production of the same energy. European regulations impose an obligation on Member States to provide annually data on energy consumption of households for end use and energy product. Data will be provided for Italy basing on data collected by ISTAT Survey on energy consumption in the residential sector, appropriately processed by ENEA and ISTAT. In this paper it is presented a methodology that allowed to define a series of dwelling types, representative of the entire national sample, as a function of building, family and environmental characteristics. These dwellings, through the application of a dynamic simulation model, allowed the generation of monthly, energy consumption profiles (for heating, cooling and domestic heat water) for each cluster of dwelling types and the evaluation of the energy consumption distribution of the residential sector for end use and energy product. [ABSTRACT FROM AUTHOR]

CO2 pipeline transportation is an important part of carbon capture, utilization and storage (CCUS) technology, and it's economical and effective when the phase state is the dense phase and supercritical phase during the transportation. When the fluid is in single-phase flow during the process of transportation, the energy required is minimum. As the temperature of the supercritical transportation is increased above 31.4 °C, heating problem occurs in the transportation process because of the influence of the ambient temperature. In this paper, the dense phase transportation and supercritical phase transportation are compared, and the results show that the dense phase transportation has much greater advantage. On this basis, in order to determine the range of parameters for CO2 pipeline transportation in dense phase and ensure safety transportation, the relationship between transportation pressure, temperature and pipeline transportation distance under the influence of different inlet temperature, pipeline flow, total heat transfer coefficient, ambient temperature, etc. are studied using HYSYS software simulator. The results showed that the flow rate and ambient temperature have great influence on the pressure along the pipeline. In order to ensure cost-effective pipeline transportation, pipeline flow rate should not be too large, with phase transition not occurring in the 300 km pipe length in dense phase transportation. This study is a basic research of CO2 pipeline transportation in dense phase. It has a reference value for the formation of a complete CO2 pipeline transportation system in China. [ABSTRACT FROM AUTHOR]

Nowadays, the massive use of fossil fuels, required to satisfy the energy needs of modern society, has caused evident climate changes which are dangerously destabilizing the ecosystem. Currently, among the sectors responsible for the increased energy consumption are the building industry and the transportation systems. As regards the latter, in particular, the main issue consists in conjugating the growing demand for personal mobility with the safeguard of the environment, providing for policies aimed at discouraging the use of private cars and increasing the use of alternative low-impact energy sources. In this context, the paper aims to analyze the effectiveness of a collective transport system which, being powered by renewable sources and designed to reduce the private car flow directed to and coming from the Mediterranea University of Reggio Calabria, is an example of sustainable urban mobility action. To fulfill this purpose the expected outcome generated by the described measure has been evaluated by both the economic and environmental point of view. [ABSTRACT FROM AUTHOR]

The cooling energy requirements are certainly a key issue in warm climates. Vapour compression refrigeration systems involve high energy consumptions and environmental emissions and that makes this kind of technology unattractive. These aspects are most relevant in buildings which have high volume and high internal thermal loads as happens often in industrial buildings. For this kind of buildings a sustainable alternative to improve indoor thermal conditions is represented by evaporative cooling systems. Such systems take advantage of the water evaporation process to cool an air stream, which could cool the supplied air or which could be itself the supplied air to the conditioned environment. In this paper a wide analysis of evaporative cooling applications is presented referring to a sample industrial building characterized by relevant thermal discomfort. The thermal behaviour of building has been evaluated using the transient simulation program TRNSYS, in which different study cases are implemented on varying the cooling system. Moreover, a kind of indirect evaporative cooling systems, called cyclic evaporative cooling, in which the air temperature can be reduced below the wet bulb temperature, has been designed. The results of the simulations were compared in terms of energy savings and thermal comfort. [ABSTRACT FROM AUTHOR]

Common rail systems are conventionally employed in diesel and gasoline engines. Pressure, precision and velocity are key factors for correct engine power management. Current systems are based on digital computers and PID control systems. When anomalies occur, recovery strategies are used and engine performance is significantly reduced. Then technical assistance is required to restore normal condition. For safety reasons this approach cannot be used in aeronautical, naval and energy-supply applications. In some cases it is necessary to utilize all the possible energy from the power unit causing significant life-reduction of the engine. In this case a progressive reduction strategy should be used and injection law should be reduced accordingly. For this purpose injection control based on fuzzy logic is more effective . In this case, traditional PID control systems are substituted by fuzzy logic control. A reference map is introduced in the Full Authority Digital Electronic Control, this map is interpreted by the fuzzy logic control system that adapts the injection law to the current engine situation. For example, if fuel temperature tends to increase over the normal level, injection pressure is reduced by the fuzzy control system and injection time is increased to obtain the maximum possible power output. This approach can be easily implemented with very simple and effective fuzzy logic controllers. This method has been experimented on a commonrail test bed and results are compared with traditional "binary recovery strategy" FADEC. Maximum power output is slightly reduced since fuzzy controllers are less effective than PID in "near reference" conditions. However, when anomalies take place or are simply beginning to appear the fuzzy FADEC behaviour is more effective and preserves engine performance more effectively. Aim of this paper it to define rules and fuzzy controllers to optimize the performance of a diesel engine in various operating conditions with particular attention to the power output. [ABSTRACT FROM AUTHOR]