Electric Heating System Research Articles

Drying Kinetics of Banana Chips: A Modeling Approach

The primary goal of this research is to identify and evaluate the most suitable thin-layer drying model to effectively interpret the drying characteristics of banana chips and determine moisture diffusivity at different drying temperatures. The study utilized physiologically mature “kapok” bananas from the local market in Jember Regency. A flash dryer with a 4000-watt electric heating system was used, equipped with a blower for air circulation, an exhaust fan to expel water vapor. The bananas were processed into chips with a thickness of 1 mm. A total of 2000 g of banana chips were dried at constant temperature according to treatment conditions (air velocity 3.2 m/s, drying at temperatures of 60, 70, and 80°C). The study found that higher drying temperatures (80°C) achieved the highest initial drying rate (35.9% in 30 min) compared to 60°C (28.0%) and 70°C (22.0%). However, the drying rate gradually decreased at all temperatures. The drying kinetics of banana chips at 60, 70, and 80°C aligned well with the modified Midilli model. Effective moisture diffusivity values for banana chips at 60, 70, and 80°C were 4.947E-9 m²/s, 5.165(10–9) m²/s, and 5.756(10–9) m²/s, respectively, indicating that drying at 80°C was the most effective. The effective moisture diffusivity value showed a strong correlation with air velocity, drying temperature, material thickness, RH, and specific material attributes. Keywords: Banana, Diffusivity, Drying, Thin layer drying, Modified Midilli Model.

Cyclic loading effects on the heat-generation performance of carbon nanotube-embedded cement composites

Abstract This study investigates the heat-generation stability of carbon nanotube (CNT)/cement composites after exposing to cyclic loading conditions. The specimens were fabricated with varying CNT contents and levels of fly ash replacement. Results showed that increasing CNT content reduced electrical resistivity, while the impact on the electrical characteristics was found to be insubstantial, even though a considerable portion of fly ash was replaced. In addition, the electrical resistivity of the specimens after exposed to cyclic loading increased. Electrical heating tests revealed both negative and positive temperature coefficient effects depending on the applied voltages. Higher CNT contents improved the heat-generation capability, but the heating capability decreased after exposed to the cyclic loadings which is deduced from the damage of CNT networks during cyclic loadings. In this regard, the authors concluded that the heat-generation stability can be significantly affected by the applied loadings. Thus, the future research will be conducted to improve the heat-generation stability of the cement-based electrical heating systems as exposed to artificial deteriorations.

Two-stage low-carbon economic dispatch of an integrated energy system considering flexible decoupling of electricity and heat on sides of source and load

Under the goal of "double carbon", in order to further enhance the level of new energy consumption and solve the problem of restricting the flexibility of the system by "ordering power by heat" of combined heat and power (CHP) units, a low-carbon economic planning strategy with flexible decoupling of electricity and heat is proposed, by introducing a new type of electric-thermal coupling equipment on both sides of the source and load. Firstly, Consideration of the low-carbon and environmentally friendly characteristics of green ammonia production and ammonia-doped combustion technologies, a wind power(WT) – power to ammonia(P2A) - CHP units - thermal power (TH) units joint operation strategy is proposed on the source side. This strategy realizes the conversion of abandoned wind to green ammonia to ammonia coal hybrid generation, the decoupled operation of CHP units and promotes the consumption of wind power and the low-carbon operation of the system. Secondly, A dynamic incentive demand response model is developed to meet the demand of high proportion distributed PV in situ consumption on the load side. The dynamic incentive price guides the distributed power-to-heat load to change the response capacity, tracks the abandonment of wind and light, realizes the flexible conversion of power and heat load, and cooperates with the source side to promote the coupling operation of electric pyrolysis. On this basis, consider the flexible decoupling capability of electric-heat coupling equipment on both sides of the source and load to establish a two-phase low-carbon scheduling model for the day-before and day-after phases. In the day-ahead phase, the source-side electric-thermal-ammonia joint operation strategy is considered, and the electric and thermal energy supply plans are adjusted centrally; In the intra-day phase, the flexible adjustment range of power-to-heat devices and the heat load inertia on the load side are taken into account, and the electricity and heat planning strategies are adjusted in a distributed-centralised manner in conjunction with the source side. Finally, through the simulation of different cases, the results show that compared with the traditional electric heating system, the total cost of the system considering the scheduling strategy proposed in this paper decreases by ￥826,900, the carbon emission decreases by 1.2t, and basically realises the consumption of wind power and distributed photovoltaic power output. The proposed scheme reduces carbon emissions, promotes the consumption of wind power and distributed photovoltaic output, and is able to reach the goal of low-carbon economic dispatch.

Investigation of the Temperature Distribution and Energy Consumption of an Integrated Carbon Fiber Paper-Embedded Electric-Heated Floor

This study examined spatial and temporal thermal performance and energy consumption. The temperature distribution in the running period was monitored in test rooms with integrated electric- and hot water-heated floors. The short- and long-term energy consumption of the two heating systems were recorded and compared. The results indicated that the integrated electric heating system generated higher temperatures for indoor air and on the exterior surface of the wooden floor than the hot water heating system; meanwhile, the difference in the mean temperatures of the exterior and rear surfaces of the electric-heated floor was 2.44 °C, while that of the hot water-heated test room was 13.25 °C. The efficient structure of the integrated electric heating system saved 22.97% energy compared to the hot water system after short-term (7 h) charging and reaching a dynamic balance, and it efficiently increased the energy utilization rate to 11.81%. After long-term charging, the daily energy consumption of the integrated electric heating system consumed much less energy than the hot water system every month. The integrated electric heating system saved 62.55% and 34.30% of energy in May and January, respectively, and consumed less than half of the energy the hot water system consumed in the less cold months. Therefore, a high-efficiency and energy-saving integrated electric-heated floor could be a potential indoor heating solution.

Study on the optimization of heating exchanger in electric heating solid energy storage heating system

This paper addresses prevalent issues of suboptimal compatibility between the heating exchanger and the thermal storage unit, poor safety performance, and overall insufficient heat exchange efficiency within the application of heating exchangers in electric heating solid energy storage heating systems. Experimental testing and numerical simulation studies were conducted. The research investigates the effect of the temperature of inlet air as well as velocity on the heat exchange performance of the heating exchanger as well as temperature variations of single-row heat pipes. Drawing upon these change patterns, an optimized heating exchanger structure is proposed and subsequently investigated through optimization simulation studies. The study results indicate that the best overall optimization effect is achieved with a heating exchanger arranged with finned tube combinations of 4 mm in two rows, 6 mm in two rows, 8 mm in two rows, 10 mm in two rows, 12 mm in two rows, and 14 mm in ten rows arranged successively from front to back. When the heating exchanger’s inlet air speed is relatively high, this combination’s heat exchange capacity surpasses the original structure. Additionally, the uniformity of air-side temperature drop improved by 44.89%, while the finned area was reduced by 25.62%.

Enhancing Power Supply Flexibility in Renewable Energy Systems with Optimized Energy Dispatch in Coupled CHP, Heat Pump, and Thermal Storage

The use of renewable energy by converting it into heat is an important form of storing energy in a usable form and improving the energy supply flexibility; therefore, the electricity–heating system (EHS) can cope with load fluctuations. However, relevant research is lacking on improving the energy supply limitations by the optimal dispatch of energy flow at the typical EHS, such as the coupled CHP–heat pump–thermal storage system (CCHTS). Based on the study of the energy supply characteristics of the CCHTS for extending the energy supply limitation, this study develops an optimal dispatch method using a heat pump (HP) and the thermal storage (TS) of heating networks to improve the flexibility of the CCHTS and the accommodation capacity of renewable energy. The maximum and minimum energy supply limitation model of the CCHTS and the output power characteristic model are established. Based on the piecewise power supply constraint, the energy flow of the EHS is optimized by using the quadratic programming algorithm. The CCHTS can significantly improve the energy supply flexibility; both coupled combined heat and power (CHP) + HP and coupled CHP + TS can improve the power supply flexibility, but the enhanced effect of CHP + HP is better than that of CHP + TS. An increase of 7.6% in wind power consumption is achieved. The consumption of renewable energy increases by 17.9% in the energy flow optimization results.

Novel approach to remote rural heating: Direct coupled photovoltaic electric heater underfloor heating system with phase change materials

Limited access to grids and the unavailability of traditional energy sources present significant challenges to effective heating in remote rural. This paper proposes a direct coupled photovoltaic electric heater underfloor heating system with phase change materials (direct coupled PVEH-UFHs), which eliminates the reliance on the power grid or conventional energy sources for heating in remote areas. The model of the direct coupled photovoltaic electric heating system (direct coupled PVEHs) and the building model with PCM floor were created and the accuracy of the direct coupled PVEHs model was verified experimentally. The study proposes using the total heating achievement rate (THAR) as the evaluation index and identifies the critical parameters affecting the system performance through sensitivity analysis. The results indicate that the photovoltaic capacity factor (PVCF), PCMs thickness and melting temperature are the key parameters affecting the heating performance of the system. The recommended 1.4 PVCF and PCM melting temperature of 294 K. The minimum payback time for system configuration that achieves 90 % THAR is 16.2 years. In summary, this paper proposes a design method and evaluation criteria for direct coupled PVEH-UFHs suitable for energy-efficient heating in remote areas.

Oral histories of domestic heating transitions in England and Sweden: lessons on how heating transitions play out across place and time

Over the last seventy years, most European countries have undergone one or more transitions in home heating provision. Moving first away from burning solid fuels and towards communal or individual central heating systems and now towards low carbon electric heating systems. Heating transitions are awash with personal, social and cultural complexity but tend to be simplified into grand narratives that tell simple stories of technological triumph. Through analysis of 21 oral histories gathered across England and Sweden, we look beyond the techno-economic dimensions of heating transitions to understand how they play out in diverse ways in everyday life over time, producing different experiences and outcomes (socially, culturally, financially) across places and social groups. We reveal similarities and divergences between the outcomes associated with different heating transition routes pursued in each country, underlining the long-lasting consequences of heating change. The research reported in this article received full ethics approval from the University Research Ethics Committees at Sheffield Hallam University and Lund University. Informed, written consent was obtained from all research participants.

Experimental Study on a Photovoltaic Direct-Drive and Municipal Electricity-Coupled Electric Heating System for a Low-Energy Building in Changchun, China

This paper takes a low-energy building in Changchun, China, as an object to test and study the characteristics of two heating modes, AC/DC (Alternative current/Direct current) switching and AC/DC synthesis, from the perspectives of temperature change, irradiation intensity, power generation, electricity consumption, etc. Firstly, the experimental research was conducted under two heating cable modes by establishing mathematical models and a test rig, and it was found that the photoelectric conversion efficiency on sunny, cloudy, and overcast days was 18%, 14.5%, and 12%, respectively. A simulation model was established by TRNSYS to run an ultra-low-energy building throughout the year. It was found that the highest and lowest monthly power generation occurred in February and July, respectively. The annual power generation of the system was 6614 kWh, and the heating season power generation was 3293.42 kWh. In the current research, the DC electricity consumption was slightly higher than the AC electricity consumption. Under conditions of similar radiation intensity and power generation, the indoor temperature of the AC/DC synthesis cable heating mode were 1.38% higher than the AC/DC switching heating able mode, and the electricity consumption were 10.9% and 4.76% higher, respectively, than those of the AC switching heating cable mode. This is of great significance for clean-energy heating, energy savings, and emissions reduction in northern China.

A Case Study of Nine Post-Hydrocarbon Ready Homes

A typical 2bed dwelling at Howgate Close, after 16months of occupation, has a daily average energy bill of 10pence/day/dwelling [1] It is proffered that Howgate Close may be the most energy efficient group of dwellings of its type, in the UK [2]. Howgate Close is a residential neighbourhood of nine single storey dwellings, operating free of fossil fuels, they are post-hydrocarbon ready. The development is located in Nottinghamshire, UK, and was completed in June 2022. All nine homes are a net annual generator of surplus renewable energy, with little to no heating demand. Six of the nine homes remain naturally heated, with no resort to the electric underfloor heating system. Exceptionally high levels of energy efficiency have been achieved with third-party verification, the As-Built SAP Rating of 143A [3] Such a rating places these homes in the top 0.01% of the 12million registered UK Energy Performance Certificate‘s (EPC) [4]. This paper provides a building Case Study that evidences performance standards making comparisons with the UK Building Regulation Compliance Standards [5] Howgate Close’s exceptional energy efficiency can be described as an aggregation of marginal gains [6] This paper is a prelude to more forensic analysis of Howgate’s in-use building performance, with the installation more advanced monitoring equipment in May 2024 for a period of two years. EWI Pro, Dr Harrall and Nottingham Trent University (NTU) are to undertake further data dissemination, providing a more forensic Howgate Case Study for ISEC 2025.

Toward residential decarbonization: Analyzing social-psychological drivers of household co-adoption of rooftop solar, electric vehicles, and efficient HVAC systems in Georgia, U.S.

The marketplace of climate solutions has grown considerably. Three technologies, in particular, exhibit strong potential for disruptive change and advancement in the residential sector: electric vehicles (EVs), rooftop photovoltaics (RPVs), and efficient heating, ventilation, and air conditioning (HVAC) systems. Many scholars have studied the adoption of these technologies; we address their co-adoption. Using a survey conducted in Georgia, we examine pro-environmental behavior, risk tolerance, and energy-related knowledge as social-psychological drivers for the co-adoption of RPVs, EVs, and efficient HVACs (including heat pumps). We conclude that some but not all of these drivers are relevant to the adoption and co-adoption of the three transformational climate solutions. Pro-environmental behaviors, for instance, appear to create conditions for “positive spillover,” propelling consumers toward adopting multiple climate solutions, whereas energy knowledge has no clear relationship with co-adoption. At the same time, the = influence of these drivers are unique to different combinations of technologies – one notable example is the significance of risk tolerance when RPV is added to technology bundles. Our paper contributes to the literature by broadening the understanding of the adoption of bundled (or co-adopted) climate solutions.

RESEARCH OF STRUCTURAL AND MECHANICAL PROPERTIES OF MEAT AS AN OBJECT OF PROCESSING IN MEAT COMMINUTOR

This work is dedicated to the study of the energy efficiency of using electric heating systems in the classrooms of Ivano-Frankivsk National Technical University of Oil and Gas (IFNTUOG), where the actual state of heating systems and their efficiency in educational building №9 were determined. An experimental study was conducted, which included determining the heating and cooling time of working surfaces and the distribution of temperatures across them in a classroom; determining the distribution of thermal energy at several levels of the room. Experimental data were obtained to evaluate the effectiveness of different electric heating systems in classrooms in standby mode, which allowed selecting the infrared heating system based on ceiling heaters as the most optimal technical solution for providing an acceptable level of comfort and energy efficiency. The effectiveness of using air thermostats for the electric heating system based on infrared heaters, which operates in standby mode, leading to excessive electricity consumption, was also studied. The results confirm that the heating system using infrared panels ensures even heat distribution, maintains comfortable temperature and humidity conditions, and is distinguished by high energy efficiency. In contrast, the use of electric convectors with an inefficient water heating system does not provide adequate air heating, especially in spacious and high rooms, where heat dissipates quickly due to insufficient insulation. The data obtained during the scientific research, along with previous studies, allow for the development of an automatic intelligent heating and ventilation control system that will use the most advanced research results in the field of efficient operation of engineering systems in educational institutions.

Scheme Design and Energy-Saving Optimization of Cold and Heat Energy Supply System for Substation Main Control Building in Cold Area

In the context of global climate change, the implementation of building energy conservation and carbon reduction, as well as the realization of zero-energy buildings, is a key measure to cope with climate change and resource depletion. A substation is an indispensable building in the process of urbanization construction. However, in existing cold areas, the heating form of substations generally adopts electric heating, which consumes a large amount of energy. This paper optimizes the existing HVAC form of substations through the rational utilization of surrounding environmental resources and puts forward reasonable building energy-saving and carbon-reduction methods. It demonstrates the feasibility of combining solar photovoltaic power generation systems, air source heat pumps, and natural ventilation to optimize energy savings and carbon reduction in the main control building of a substation in a cold area. The computational fluid dynamics (CFD) method is used to demonstrate the feasibility of natural ventilation during the summer and transition seasons. The data indicate that the installation of a solar photovoltaic power generation system results in an average annual power generation of 18.75 MWh. Additionally, using an air source heat pump can save 44.5% of electricity compared to electric heating. When both a solar photovoltaic power generation system and an air source heat pump are used to provide a building with cold and heat sources, the annual emissions of CO2 can be reduced by 4.90 tons compared to a traditional electric heating system.

Dynamic optimal control strategy for distributed electric heating system under electricity pricing lever

To address wind curtailment, a method is proposed to improve wind power consumption by controlling user demand response. Considering residents’ comfort demand for heating in winter, a distributed electric heating system is established and an optimal control model is established to enhance wind power consumption capacity. By considering the influence of electricity price and comparing the optimal model under basic tariffs, time-of-use and real-time tariffs, a dynamic optimal control method for distributed electric heating systems driven by electricity price leverage is proposed. The simulation results show that the method can effectively guide electric heating users to actively participate in load regulation, significantly improve wind curtailment and ensure economic and stable power grid operation. Using different electricity prices as leverage can systematically incorporate a large number of distributed electric heating users into the controllable load of wind power consumption, providing a new method for large-scale wind power consumption.

Design and operational strategy optimization of a hybrid electric heating system with phase change materials for energy storage in nearly zero energy buildings

Nearly zero energy buildings (nZEBs) and the associated research on heating energy systems are gaining increasing attention. To enhance PV self-consumption capacity in nZEBs, a hybrid electric heating system with phase change materials (PCM) for energy storage using photovoltaic (PV) and grid power was developed. To study the system's performance, an experimental bench was set up, and mathematical models for energy efficiency and operational strategy were developed. Furthermore, a research building was chosen as the scenario to investigate the operational performance of the system. The analysis focused on assessing the impact of varying PV and battery capacity, specifically concentrating on load flexibility transfer capability and energy flow within the system. The results indicated that when implementing the hybrid electric heating system with varying PV and battery capacities, significant transfers of both heat and electricity loads could be achieved, leading to peak price electricity usage remaining below 10 %. Regardless of the manner in which PV is utilized, the system facilitates the transfer of both heat and electricity loads, resulting in peak price electricity usage remaining below 5 %. Through an analysis involving the optimization of system capacity and operational strategies during a simulated one-week period in the heating season, the results revealed that the utilization of a battery with a rated capacity as low as 3.69 kWh led to an increase of 10.93 kWh in PV self-consumption, resulting in a noteworthy cost reduction of 15.6 %.

Competitive Equilibrium Analysis for Renewables Integration in Dynamic Combined Heat and Power Trading Market

With the increasing interdependence among the electricity and district heating systems in economy and physics, this study focuses on the equilibrium analysis of the combined heat and power market (CHPM). Based on the gradient method in game theory, a dynamic model characterizing renewables uncertainty and negotiation process among dominant participants is established. Inspired by modern control theory, the dynamic model can be viewed as state equations in which the actions of participants are control signals, and the system states, such as nodal price and bus voltages, are treated as system state variables. A detailed proof for asymptotic stability around the market equilibrium is derived, and its region of attraction is quantified. The resulting sufficient conditions can also be used to quantify the impact of renewable energy uncertainty and congestion constraints on market stability. The whole trading process is designed to be implemented by distributed algorithms to reduce the computation burden of central authority. Numerical tests on two cases with different scales are conducted to demonstrate the theoretical analysis and the application of the proposed sufficient conditions for market stability.

The concept of transitioning centralized heating systems in multi-apartment buildings to decentralized electric water heating

In recent years, there have been significant changes in the perception of the feasibility of using electricity as a source of thermal energy for household heating systems. Electric boilers are considered an important element in the energy transition from the use of hydrocarbon fuels to renewable energy. For a modern comprehensive approach in assessing the feasibility of various heating systems, it is necessary to consider not only the operational costs but also the energy, environmental, economic requirements, safety of operation, and maintenance costs, from both the consumer’s perspective and in terms of the historically evolved role of the state and the social significance of providing heating to the population. This study compares these factors for centralized heating systems, apartment-based systems using wall-mounted gas boilers, autonomous systems using boilers on different types of fuel, and water electric heating systems. Conclusions are presented on the advisability of gradually transitioning the heating supply of multi-apartment buildings from centralized to individual apartment-based electric water heating.

Multi-scale flexibility assessment of electrical, thermal and gas multi-energy systems based on morphological decomposition

The rapid development of renewable energy has also had an impact on the flexibility of multi energy systems such as electricity, heat, and gas. To analyze the flexible characteristics of multi energy systems at multiple time scales, a multi-scale flexibility evaluation method based on morphological decomposition is proposed. The net load curve is decomposed using mathematical morphology methods, and a multi-scale energy storage configuration method based on the flexibility of electric heating systems is proposed. The analysis data shows that the probability of insufficient upward flexibility, margin expectation, and insufficient expectation of the scale weighted flexibility index are 1.12%, 3.98%, and 1.16%, respectively, while the probability of insufficient downward flexibility, margin expectation, and insufficient expectation are 0.73%, 4.54%, and 0.56%, respectively. The introduction of energy storage and controllable load simultaneously results in an overall downward flexibility index of 0.92% for the system. The results indicate that controllable load can improve the economy of system peak shaving, providing more options for energy storage and configuration in multi energy systems.

Solar-Air Source Heat Pump Water Heater for Scorching Climatic Condition: Energy, Exergy, Economic and Enviroeconomic (4E) Exploration for Sustainable Future

As solar-powered air source heat pump is an emerging water heating technique in scorching climatic conditions, it is necessary to explore their performance in terms of energy, exergy, economic, and environeconomic (4E) perspective. Henceforth, current research experimentally investigates and reports on 4E of Direct Expansion Solar-Air Source Heat Pump water heater for hot regions. A heat pump with a dual source evaporator is proposed in two working modes: solar air source mode and air source mode. The impact of ambient conditions on the thermal performance, such as power consumption, evaporator and condenser capacity, heating time, coefficient of performance, and exergy efficiency of the heat pump water heating system in both the working modes, was experimentally investigated. Results depict the coefficient of performance of the proposed heat pump system in solar air source mode and air source mode in the range of 2.37-5.05 and 2.26-4.21, respectively. On average, the system heating time in solar air source mode is 16.5% shorter than in air source mode. Based on the simulation results, compared to a conventional standard electric heating system, the payback period and lifetime carbon-dioxide mitigation savings cost of the proposed dual-source heat pump system are about 616 days and $179866, respectively.

The potentials of thermal energy storage using domestic electric water heater technology with PV systems in the EU countries

Recently, there has been a considerable decrease in photovoltaic technology prices (i.e. modules and inverters), creating a suitable environment for the deployment of PV power in a novel economical way to heat water for residential use. Although the technology of TES can contribute to balancing energy supply and demand, only a few studies have investigated its potentials. These days, TES technology can play a significant role in mitigating the negative network effects resulting from higher proportions of electricity generated by PV systems. The presented research examined the possibility of applying a new technological direction in connection with PV utilization in the European Union (EU), with a view to promoting the spread of cost-effective energy storage and increase energy independence. The purpose of this study was to examine the deployment of combined TES and PV systems in the EU countries by the example of a special 3.5 kW inverter and a 200-l domestic electric water heating system. The innovative significance of the research is that it explores this practical solution, by determining the seasonal energy saving potentials of the application of this sensible heat storage method in the context of all the EU countries.Graphical HighlightsThe recent extraordinary increase in installed photovoltaic (PV) capacity cannot be successful without integrating it with energy storage (ES) to store generated surplus power to be consumed later.Technological developments and the trend of falling PV module and inverter prices makes it possible to apply economical solutions for hot water production for domestic hot water use and/or assisting space heating, based on the use of solar energy.The combination of modern inverter technology, PV and domestic electric water heating systems provides a storage solution for PV energy with considerable cost saving potentials in the countries of the EU.Many factors influence the ideal and economical size of such combined systems and their components, which need careful consideration and calculation.For a better utilization of the potentials offered by this new solution more complex analyses and the investigation of the ways of linking thermal energy storage (TES) and PV systems and possibly other technologies is necessary.DiscussionHow can the efforts to decrease the household consumption of energy used for heating water and space heating connected to the issue of integrating variable renewable energy sources into energy systems?How can currently commercially available technology be used for storing electrical energy generated by photovoltaic systems in the form of heat energy?What determines the potential energy and costs savings achieved by a combined system of a small photovoltaic power plant and a home electric water heating system for the households in the various countries of the European Union?What are the potentials of the suggested system in terms of energy and costs savings in the context of households in the EU countries?