Consumer Of Thermal Energy Research Articles

Design-Point Techno-Economics of Brayton Cycle PTES for Combined Heat and Power

Abstract Pumped thermal energy storage (PTES) systems are grid batteries that use heat pumps to create both hot and cold thermal energy stores when there is excess electricity and then use a power cycle to convert the thermal energy into electricity when there is demand for electricity. In normal operation, Joule-Brayton PTES discharges low-grade heat at temperatures useful for thermal energy consumers like district and industrial heating. Furthermore, PTES designs, like conventional combined heat and power (CHP) technology, can be modified to sacrifice some round-trip efficiency (RTE) to increase the temperature of heat rejection. This paper uses design-point performance and cost models that provide a detailed understanding of the efficiency and cost trade-offs of rejecting heat at various temperatures in ideal-gas Brayton PTES configurations. First, we keep the heat rejection in its nominal location in the PTES system. Next, we move the heat rejection to the discharge turbine exit. We define design-point metrics that isolate both the cost and performance penalty associated with the hotter heat rejection and attribute it exclusively to the heat economic metrics. We find that the levelized cost of heat, including the cost of thermal energy storage (TES) buffering the PTES and heat off-taker, compares favorably versus electric technologies and is less than the cost of natural gas for low temperature scenarios and competitive with the cost of natural gas in some regions of the contiguous United States in high temperature scenarios.

Current Trends and Solutions for Port Decarbonisation: A Systematic Literature Review

The energy sector is changing rapidly today. Global warming and other environmental challenges contributed to several international agreements aimed at fostering fossil-to-renewables debt. Decarbonization is undoubtedly a challenge, but at the same time a potential for development. The energy sector is made up of many sectors that have their own specificities, constraints, and opportunities. This study reflects progress in the decoration of ports. Ports are a place that often brings together energy consumers of different levels and types – water and land transport, as well as consumers of thermal energy, electricity, and fuels. The bibliometric analysis method is used at publication to analyze current trends. The results show that despite the existing challenges and historic delays with the entry of renewable energy sources into ports, scientific progress is prepared to offer solutions to decarbonise port energy consumers as well. These studies reflect that hydrogen technologies are the most prospective solution, but many aspects and links need to be considered to ensure the transformation of the sector.

Моdern heat and steam supply systems of industrial enterprises using deep utilization of the technological steam energy potential

Steam supply systems of industrial enterprises, as a type of heat supply system, are a large consumer of primary energy in national energy balances. In turn, due to the specificity of thermodynamic steam processes, steam supply systems of industrial enterprises in practice have significant unused potential of secondary energy resources (SEP). Modern steam supply systems should be built exclusively when evaluating their exergetic efficiency, which will make it possible to evaluate the effectiveness of such systems grossly in all elements of the life cycle of the project: energy, economic, ecological and even social. The article shows modernized thermal schemes of steam supply systems, for which it is possible to achieve additional electrical power at the level of 135-250 kW/(kg/s) when devices with a relative internal efficiency of up to 60-70 % are operating. In combination with an increase in the percentage of condensate return and the utilization of secondary energy resources (SRP), the increase in energy efficiency of the system is 2-4 %, and the absolute value of exergetic efficiency is 16-22 %, taking into account the exergetic efficiency of the boiler unit. Low-potential "tail" consumers: the heating system, the hot water supply system - increase the exergy efficiency of the steam supply system of an industrial enterprise by 0.2-0.6 % in the case of joining on the steam side of secondary boiling. Any processes of generating electrical energy are associated with obtaining a significant amount of thermal energy, and must be accompanied by its utilization; enterprises that use steam as an energy carrier (the same applies to energy enterprises such as thermal power plants and nuclear power plants) for the deep utilization of hydroelectric power plants must have thermal energy consumers in their composition, which can act as communal household consumers (if they exist), as well as new technological consumers of thermal energy.

The Russian Heat Supply: Problems and Solutions

ABSTRACT In Russia, two-thirds of the heat supply industry is located in harsh climatic conditions. This is also the most important public industry of the economy and largely determines the country’s energy security. Many problems have accumulated during the reform of the heat supply industry, which are connected with the technological, organizational, and economic problems of the electricity industry. This is primarily due to the lack of mechanisms to manage the industry’s functions and development. The target model of the thermal energy market adopted by the Russian government has not eliminated these problems but further aggravates the situation. To change the current situation, it is necessary to organizationally transform the retail electricity and thermal energy markets, change the relationship between the suppliers and consumers of thermal energy, introduce a tariff-based system founded on market principles, and implement the use of new technologies. This will ensure technological transformation and improve the reliability and availability of the heat supply. To achieve this will require the development and adoption of the appropriate legislative and regulatory measures.

Методика оценки влияния эксплуатационных параметров на работу турбопитательного насоса

Background. Turbine feed pumps (TFP) are one of the main consumers of thermal energy for in-house needs of thermal power plants and nuclear power plants. Currently, much attention is paid to improve the efficiency of operation of turbine feed pumps. Thus, it is necessary to assess the impact of operational parameters. The problem is that it is necessary to process a large array of data. The solution to the problem is the development of a methodology that allows quantitative and qualitative assessment of operational parameters. Materials and methods. As initial data, the authors have used the data of 20 thermodynamic and hydraulic parameters recorded during the industrial operation of the TFP equipment and the equations of thermal balances to find the key performance indicators of the TFP. A complex of multidimensional statistical methods is used for data processing, i.e cluster and factor analysis in the Statistica software package. Results. A methodology to assess the impact of parameters on the operation efficiency of the TFP has been developed. The cluster analysis method is used to diagnose and classify the parameters under study. By the method of factor analysis, several parameters have been identified: feed water flow in the pipeline behind the TFP, differential pressure of water of the TFP, condensate flow in the pipeline behind the TFP condensate pumps, pressure drop of circulating water before and after the TFP condenser, condensate temperature of the drive turbine. The analysis of the results has showed that the identified parameters are the main components of the useful power of the turbine feed pump and the criteria for the efficiency of the TFP. Conclusions. The proposed methodology makes it possible to carry out a quantitative and qualitative assessment of operational parameters, solve the problem of processing large amounts of information, reduce the time and complexity of calculations. The results obtained are based on the developed methodology and can be used to design a statistical model using neural network technologies. This methodology can be chosen to evaluate the operation of technological systems and subsystems at thermal power plants and nuclear power plants.

Evaluating the Effectiveness of Energy-Saving Retrofit Strategies for Residential Buildings

Most of the apartment buildings in the Republic of Kazakhstan were built more than 40 years ago. The buildings were designed according to traditional approaches and are the main consumers of thermal energy. The work aims to study various energy-efficient options for modernizing residential buildings and to quantify the actual energy savings and payback period. The paper presents the results of monitoring the energy efficiency of apartment buildings for the period before and after repairs. The results of assessing five thermo-modernization options showed that mineral wool insulation (more than 0.15 m thick) of external walls and roofs saves more than 30 Gcal/year of heat energy. Installation of double-glazed windows with insulating vinyl frame and insulating front doors saves up to 3 Gcal/year of heat energy. It was found that heat recovery ventilation with good thermal tightness of a building can reduce the consumed heat up to 21 Gcal/year. According to the results of the energy audit of the studied buildings, the best modernization options (which increase buildings' energy efficiency 3 times) were selected. A comparative analysis of calculated and actual data on Energy Consumption (EC) after buildings' renovation showed a difference of 10%. The most effective and economical method of apartment buildings' modernization with heat energy consumption of about 0.05 Gcal/m² per year was determined. The results obtained can be used in the passport of buildings and for future research in the field of housing architecture modernization.

Demand side management in the cooling supply of brewing processes

Due to the increasing supply of volatile renewable energy, demand side management on the consumer side by temporally shifting electrical power demand is needed. Industrial cooling systems in particular offer great energy-flexibility potential since cooling energy is mostly electrically generated and almost all cooling systems already have thermal energy storage. Compared to other industrial sectors, the share of cooling energy demand in the food and beverage industry is particularly high. Especially in breweries, where large beer tanks require cooling, promising energy-flexibility potentials are expected. In order to quantify the technical energy-flexibility potential in the brewing process, relevant thermal energy consumers and process parameters are identified in a first step. Then, various energy-flexibility measures as well as their possible implementation barriers are identified and compared in terms of their technical energy-flexibility potential. The potential of the most promising energy-flexibility measure is then examined in detail by taking the cooling power demand and operating duration into consideration. The analysis shows that the focused beer cooling process in the storage tanks, accounts for around 45 % of the total cooling demand and can be shifted in time by up to 96 hours. Finally, the economic energy-flexibility potentials are determined. Taking advantage of the lowest electricity prices within one week, the results of a retrospectively optimized operation strategy show that energy cost savings of approx. 9 % can be achieved, without taking possibly increasing energy price fluctuations into account.

A solar-driven 5th generation district heating and cooling network with ground-source heat pumps: a thermo-economic analysis

• Evaluation of a 5 th generation bidirectional heating/cooling network for 50-buildings • Water-to-water, ground heat pumps and a photovoltaic field are designed • Primary energy saving and avoided CO 2 emissions are 76% and 64% • High payback period due to costs of excavation, pipe laying and heat pumps District Heating and Cooling is considered an efficient solution to address the thermal energy demand of the building sector and reduce its environmental impact. In this paper, a 5 th generation bidirectional heating/cooling network is designed and modelled. The network is coupled with water-to-water heat pumps, ground heat pumps and a photovoltaic field and is designed to meet the energy requirements of a 50-building district in the city of Leganés (Madrid). All components are modelled in TRNSYS 18. The studied network achieves a primary energy saving index of 64% and reduces the CO 2 emissions by 76% relative to the current situation. The economic analysis of the system results in the relatively long payback period of 33 years, mainly due to the high costs of excavation and the installation of the heat pumps and pipes. With the current design, the photovoltaic field meets only 30% of the electricity demand of the district. However, additional energy storage could help align the power production with the actual power demand better and avoid grid balancing issues. The inclusion of other types of thermal energy consumers would also enhance the performance of the network by increasing the simultaneity between cooling and heating demands.

Modeling of Seasonal Variations of Thermal Energy Production by an Electric Power Company based on Neural Network Technology

The paper considers the problem of modeling the dependence of the value of thermal energy production by an electric power company on the air temperature using neural network technology. As an example of an electric power company producing thermal energy, the Public Joint-Stock Company (PJSC) Yakutskenergo. As consumers of thermal energy, organizations, enterprises and the population of the city of Yakutsk, are located at latitude 62 and characterized by a cold northern climate. The numerical experiments carried out in this paper have shown that the general trend of the temperature dependence of thermal energy production, observed empirically, is well described by a neural network

Applying Modern Information Technologies for Thermal Energy Accounting in the Operational Search for Humidification of Thermal Insulation

In modern realities, developing the centralized heat-supply system in Russia is associated with a constant search for reserves for saving heat energy, its rational use, and a constant increase in the reliability and energy efficiency of heat supply to consumers. The solution to the problem of increasing the reliability of the operation of heating networks and maintaining their operability and durability is not limited to the replacement, reconstruction, and modernization of actually worn out, emergency, sections of heating networks that have not passed hydraulic tests. It is equally important during the operation of pipelines to maintain the regulatory conditions that determine their durability. The statistically most significant reason for the failure of heating networks is external corrosion of the metal, which, in turn, is most often caused by the pipe being in a humid environment or simply in water when the channel is flooded. The paper considers the possibility of increasing the reliability of heating networks by timely detection of deviations from the standard of the actual operating conditions of the heating network sections, which are in a humid environment that intensifies the processes of external metal corrosion. The rapid growth in the number of thermal energy meters installed at the facilities of district heating networks and facilities for consumers of thermal energy, together with the use of modern measuring instruments and systems for remote transmission of meter readings, creates the prerequisites for the development of a software product. It is proposed to use a software product that analyzes the operating conditions of heating networks in real time and notifies about their deviation from the standard values. A technique has been developed for the automated calculation of the coolant temperature’s standard values.

Use of Cotton Apparel Waste as an Energy Source for Biomass Boilers: A Feasibility Study

The steady growth of the Sri Lankan apparel manufacturing sector over the last three decades has resulted in generating large amount of solid apparel waste. Currently, it is a massive environmental and financial burden of the sector. As a solution, few apparel manufacturers have initiated using apparel waste, specifically the cotton apparel waste for biomass boilers. The apparel sector as one of the major thermal energy consumers, they consider it as a possible solution not only for the apparel waste disposal issue, but also for the challenge of getting continuous supply of firewood for the boilers. However, the promotion of such a solution throughout the apparel industry is impractical without a feasibility study in terms of social, environmental, financial, legal and technical aspects over its mechanism. Therefore, this research focused to identify the feasibility of using cotton apparel waste for biomass boilers as an energy source. Towards this aim, a qualitative research approach was followed involving the case study strategy. Basically, two cases were selected and analysed the feasibility of using cotton waste for boilers under pre-determined feasibility criteria in detail. Data collection for the case study was done through a document survey and expert interviews. Findings revealed the entire feasibility of environmental, financial, legal and technical aspects and in overall it can be concluded that the use of cotton apparel waste for biomass boilers as an energy source is feasible. Accordingly, this study provides insights into making decisions on managing both waste disposal and heat energy requirement issues of the apparel factories.

Applicability of information technologies in energy conservation

The article describes the computational complex designed for large-scale mathematical modeling and optimization of intra-quarter thermal regimes heating networks. Developed software allows to manage all users of thermal energy and carry out its accounting. On its basis, a strictly analytical system of targeted budget subsidies to individual consumers of thermal energy can be built, taking into account the social norms of housing, the estimated and actual power of heating devices, the location of the apartment in the house and the state of its enclosing structures. The article concludes about the effectiveness of the proposed mathematical modeling method in the organization and effective management of ensuring energy saving in the design of heating networks.

Segmentation of heat energy consumers based on data on daily power consumption

Purpose. Improving the quality of the analysis of energy consumption modes of buildings of educational institutions by determining the typical patterns of their consumption by the k-means method based on statistics of thermal energy consumed, their area, outdoor and indoor air temperature. Methodology. Methods of statistical and intellectual data analysis, optimization methods, k-means method. Findings. It is shown that most of the researched consumers of thermal energy have similar patterns of its consumption and can be divided into separate segments according to the peculiarities of functioning. The used data set is diverse as it includes three groups of data (conditionally formed by the type of educational institutions). The buildings in groups have different areas, internal temperature to be maintained, operation modes of heating systems and so on. For each of the groups, the number of clusters corresponding to low, medium and high values of heat consumption is determined. It was found that the amount of the consumed heat and consumer behavior depends on the day of the week. The obtained results can be difficult to generalize for all existing types of buildings, but it is expected that communal buildings may have similar consumption patterns, as operating modes and norms of internal microclimate remain the same for different temperature zones and territories. Originality. The method for dividing the consumers of thermal energy into segments on the basis of the data on daily energy consumption applying the k-means clustering algorithm, implemented in the programming language R, is further developed. For the first time, it has been proposed to consider not one, but three groups of objects of the educational institutions. It is proposed to determine the modes of energy consumption by buildings analytically by taking into account such parameters as the area of buildings, the amount of heat consumed by them, external and internal air temperature. Practical value. The results of the research are useful for heat supply companies, municipalities and can be used to develop programs and policies for energy efficiency. The given information and analytical support create a basis for the development of software solutions with the function of integration into local energy monitoring systems of a separate building, energy management system of the district and/or city. The presented results provide an opportunity to predict the cost of energy resources used for heating buildings, which increases the efficiency of engineering systems of buildings.

The project solution of the refrigeration machine scheme with the heat utilization of condensation

Refrigeration machines are widely used in various industries to produce artificial cold. In the process of maintaining low temperatures, the refrigeration machine generates a lot of heat to compress a refrigerant, which is not used in the future, and during the condensation it is released into the environment in the form of water vapor. This negatively affects to the environment because of increasing the concentration of greenhouse gases in the atmosphere. And the use of chlorine-containing refrigerants causes the destruction of the ozone layer. To reduce environmental damage, it is necessary to increase the energy efficiency of refrigeration machines and develop schemes that allow the use of low-grade heat, which is released during operation. In the work, a scheme of a refrigeration machine was developed, which allows utilizing the heat of condensation, using it for various consumers of thermal energy, therefore allowing to reduce emissions of harmful substances into the Earth’s atmosphere and increase technological capabilities of cooling.

Improving Energy Efficiency of Thermal Processes in Healthcare Institutions: A Review on the Latest Sustainable Energy Management Strategies

Healthcare institutions consume large amounts of energy, ranking the second highest energy-intensive buildings in the commercial sector. Within developed countries, the energy consumption of healthcare institutions may account for up to 18% of the overall energy usage in commercial sectors. Within developing countries, such as South Africa, the energy consumption of healthcare institutions is observed to be a close second to the food service sector. Energy consumption of healthcare institutions per bed typically range from 43–92 kWh per day. In this paper, the largest energy consumers in South African healthcare institutions are identified and appropriate energy-efficiency (EE) initiatives are proposed, in terms of performance, operation, equipment and technology efficiency (POET). Two main thermal energy consumers are identified as heating, ventilation and air conditioning (HVAC) and water-heating systems. These systems are critical to patient health and may be classified as non-deferrable loads. Therefore, several initiatives are suggested to improve the energy efficiency and demand-side management capability of these systems. These initiatives are subdivided into different levels: the conceptual level, active level, technical and further improvement level, as defined in the POET framework. At each level, energy-efficiency initiatives are introduced based on potential energy savings and the effort required to achieve these savings. In addition, model predictive control (MPC) approaches are discussed and reviewed as part of the further improvement section. Average possible energy savings ranged from 50%–70% at the conceptual level, while energy savings of 15%–30% may be expected for energy-efficiency initiatives at the active level. EE activities at the technical level and the further improvement level may result in savings of 50%–70% and 5%–10%, respectively.

Energy saving potential from served thermal energy and in heating buildings of Russia’s northern region

The subject of this research is energy saving of the served thermal energy in thermal energy supply by the producers and in heating of the objects by the consumer. The goal of this work is to reveal the potential of energy saving of served thermal energy as a tangible target of economic policy of the region. The results of this research demonstrate the energy saving potential from served thermal energy of Russia’s northern region, as well as the potential for energy saving by the consumer of thermal energy. The results of this research can be applied in calculated targets of energy saving of served thermal energy in the Sakha Republic (Yakutia), as well as a method of calculation for other regions and consumers. The targets can in turn serve as encouraging motives for a more active crediting of thermal energy saving by commercial banks and/or venture funds created for these purposes. The author utilizes the method of marginal comparative analysis of actual expenses of a company in heating with normative and tax expenses. The scientific novelty consists in precise delineation of the zones of responsibility in the area of thermal energy saving between thermal supply of the producer and heating of the consumer, combination of various method in determining the potential of thermal energy saving in the region and separate objects of heating, as well as continuity in introduction of heat-saving measures in heating of objects.

Energy Recovery from Brewery Waste: experimental and modelling perspectives

Food and drink processing industries are extremely large consumers of thermal energy as well as bio-wastes producers. The utilisation of bio-wastes for energy recovery appears to be a good opportunity to improve the overall efficiency of process industries. In this study, waste generation, management and energy auditing of a micro-brewery located in the north east of England is investigated. Fermented grains and hops are disposed as organic wastes after the production process. Hence, this study focuses on recovery of energy from these wastes through anaerobic digestion process. Experimental work was carried out in the laboratory for the wastes characterisation. The waste samples are then anaerobically digested at 55 ⁰C and 35 ⁰C with a 5L laboratory scale continuous stirred reactor using 5 gVSL-1 and 25 days organic loading rates and hydraulic retention times respectively. Further to the experimental work, simulations were completed to evaluate the feasibility of the process. ASPEN plus simulation software was used to carry out the simulations using a novel approach for AD which is based on the ADM1 model. The experimental results showed that biogas can be produced at mesophilic and thermophilic conditions: 3.0 and 2.6 litres per day respectively. At thermophilic conditions, the methane content is 65 % while at mesophilic conditions, it is 55%. It is also found that the values of the final biogas production from the simulation were similar to the ones obtained in the experiments (-6.85%). However, the model would need further modifications to be able to accurately predict the biogas compositions. The result shows that the thermophilic process is able to fuel 126.01 kW boiler while mesophilic process can power 76.48kW boiler.

Energy-saving automated system for microclimate in agricultural premises with utilization of ventilation air

Agricultural production is a large consumer of thermal energy for various processes. Heat is necessary to maintain the microclimate on livestock farms in the cold season. Previous studies have reported that heat recovery of ventilation air can reduce thermal energy consumption by up to 40–60%. However, most of these studies were retrospective and descriptive in nature and they did not take into account the peculiarities of agricultural production technologies. The energy-saving method of microclimate support for livestock farms of a decentralized type is described. It is based on the principles of exhaust air heat recovery, ozonation and deep air recirculation. The article deals with the structural and technological schemes of the ventilation-heating device implementing this method. The main statements of calculation methods including the thermal-power, electrical and structural calculations are described. Polyethylene terephthalate film is used as heat exchange surface. The design constant of the heat exchanger is 180 W/°C. Exergy efficiency for the heat exchanger equal to 0.48 relative units. An expression was obtained to determine the convective heat transfer coefficient in the electric supply air heater. Corona discharge ozonator is used for purification and disinfection of circulating air. The experimental stand is used for automated registration, transfer, processing and storage of data. The results of experiments confirming the energy efficiency of the electrothermal installation are reflected on the charts. The implementation of the described method provides reduction of energy consumption up to 55%.

MOVBIO - Mobilization of Biomass for Energy Recovery Towards a Sustainable Development

The MOVBIO project - Mobilization of pruning biomass for its energy recovery aims at the recovery of existing biomass which, due to its special characteristics, currently does not have a defined use circuit and has no energy use. In particular, by means of the evaluation of the technical and economic feasibility of adaptations in the processes of pretreatment and thermal utilization, it will be facilitated the energetic valorization of pruning biomass of agricultural origin (vines, olive trees, fruit trees) and urban biomass pruning of parks and gardens). The project aims to strengthen the economic model, making it more sustainable through the efficient use of residual biomass and the promotion of business innovation. In order to do so, it is essential to evaluate the real potential for energy recovery of the residual biomass, to make its extraction from the field technically efficient, to characterize as fuel and to adapt the combustion technologies, making them efficient for their final thermal and electrical use. Developing a new management model for this type of biomass will have an impact on companies providing agricultural services, thermal energy consumers, farmers and local governments. The innovative nature of the proposed approach is based on the assessment of the entire value chain, analyzing in detail the characteristics of the selected biomass Keywords : Cross-border Cooperation, Biomass, Energetic Valorization, Spain, Portugal

Carrying Out Energy Audits to Determine Measures to Save Energy Resources

It is important for a modern consumer of thermal energy to know and be able to reduce the consumption of thermal energy, for which purpose an energy audit should be conducted. Today, three types of energy audit of residential buildings are used in Ukraine. The first one is development of the energy performance certificate of the building. The obtained energy performance certificate will give an idea of the level of thermal losses of the building and identify the main areas where measures to reduce the consumption of energy resources should be taken. The second method involves carrying out experimental studies to determine the class of air permeability of enclosing structures, which also makes it possible to assess the level of heat losses of the building and the condition of the ventilation system of the building. The third type of energy audit involves carrying out thermal imaging of the building envelope for the subsequent analysis of infrared images. A methodological approach has been developed for processing multiple infrared images. An energy inspection of a residential house has been conducted on the basis of which an energy performance certificate was compiled. The premises of the residential building have been tested for air permeability. Considering the main types of energy audit, its advantages and disadvantages have been determined both for the consumer and for the employees who conduct the audit.