Electric Heating System Research Articles

Experimental study of hypervapotron channel with square fin structure for divertor cooling by one-side, electric joule heating system

The lack of cooling capacity to maintain the thermal steady state of the divertor is becoming a severe engineering problem in preparation for DEMO fusion reactor. But, there is not much literature comparing with the existing sub-cooled flow boilng heat transfer correlation and analyzing the Hypervapotron boiling curve. To simulate the fusion thermal condition, experimental loop that can withstand high temperature (150℃) and high pressure (20 bar) was constructed. And one-side electric joule heating system that can apply heat flux of up to 10.4 MW/m2 was developed. In addition, it was verified that stable operation is possible by confirming that the flow rate and the channel inlet temperature fluctuation rate are 1% or less, respectively. This experiment was carried out to evaluate the boiling heat transfer of Hypervapotron cooling channel at 10 bar, 40 ∼ 80 subcooling, 0.108 ∼ 0.284 kg /s and maximum effective heat flux of 6.87 MW/m2. Among the sub-cooled flow boiling heat transfer correlations, Thom correlation (1965), Jens & Lottes correlation (1951), and Aaladiev correlation (1957) differed significantly from the experimental data. But Shah 1977 (error rate: 4.75 %) and Kandlikar 1998 (error rate: 16.57 %) correlations were well predicted.

Improving the efficiency of electrical energy distribution with decentralized electric heating control based on nash equilibrium

The widespread use of electricity determines the development of new methods for effective control of electrical energy consumers in the face of changing constraints. A model of a decentralized control system for a group of electric room heaters based on the collective behavior of automatic machines interacting with a random environment with a limited resource distribution is studied. The considered problem differs from the known ones in that the distribution participants are limited in the use of the resource by the “all or nothing” condition. This means that each electric heater at the current time can use a fixed amount of energy resources or refuse it, and the third is not provided. The decision to connect the heaters to the electrical network is made when performing the Nash equilibrium. The Nash equilibrium condition in this work means that the unused power of the electrical network is lower than the power of any heater not connected to the electrical network. The self-organization procedure of a group of electric heaters is studied. A model of a control system for electric heaters has been developed with the task of distributing a limited resource of electrical energy based on Nash equilibrium, using the principles of decentralized control, information technologies for the development and implementation of control actions by a group of heaters. The experiments carried out have confirmed the effectiveness of a decentralized electric heating control system and allow us to recommend it for practical use. It is shown that the proposed approach opens the way to the construction of cost-effective intelligent electric heating systems

Economic, environmental, and pathogenic impact of point-of-use water heating in continental climate households

Water heating represents a large fraction of energy consumption in the residential sector, and it has significant health, economic, and environmental implications. However, it is well known that temperatures between 20 °C and 42 °C promote the multiplication of Legionella species, which are the causative agent of the Legionnaires' disease, a life-threatening form of pneumonia. Conventional tank water heating systems could be reservoirs of Legionella species, and that is why the replacement of these systems with tankless point-of-use water heating (POUWH) systems may keep a low-risk concentration of Legionella pneumophila in the water delivery and reduce energy consumption. This strategy may attain its maximum effectiveness in continental climate regions like Kazakhstan, where water mains-supply does not exceed 20 °C all year-round. Nevertheless, as POUWH systems depend on electricity, greenhouse gas (GHG) emissions may change compared to storage-based or even in-line water heating systems, depending on the energy source of grid electricity and the base-case heating system. This study assesses the use of POUWH systems in Nur-Sultan city, the capital of Kazakhstan, and compares it with commonly used electric and natural gas storage-type water heating systems. The power grid in the country heavily depends on coal (~70%), and the present analysis demonstrates that POUWH is economically competitive and reduces the greenhouse gas (GHG) emissions when compared with electric storage-type water heating (ESWH). However, the opposite happens when POUWH is compared with natural gas storage-type water heating (NGWH). The financial analysis revealed the fuel cost as the most influential factor in economic viability. Despite its debatable economic advantage, POUWH is favored by its intrinsic lower risk of Legionella sp. concentration in delivered hot water, a crucial element that should be considered in a final decision.

Thermal Calculation and Experimental Investigation of Electric Heating and Solid Thermal Storage System

Electric heating and solid thermal storage systems (EHSTSSs) are widely used in clean district heating and to flexibly adjust combined heat and power (CHP) units. They represent an effective way to utilize renewable energy. Aiming at the thermal design calculation and experimental verification of EHSTSS, the thermal calculation and the heat transfer characteristics of an EHSTSS are investigated in this paper. Firstly, a thermal calculation method for the EHSTSS is proposed. The calculation flow and calculation method for key parameters of the heating system, heat storage system, heat exchange system and fan-circulating system in the EHSTSS are studied. Then, the instantaneous heat transfer characteristics of the thermal storage system (TSS) in the EHSTSS are analyzed, and the heat transfer process of ESS is simulated by the FLUENT 15 software. The uniform temperature distribution in the heat storage and release process of the TSS verifies the good heat transfer characteristics of the EHSTSS. Finally, an EHSTSS test verification platform is built and the historical operation data of the EHSTSS is analyzed. During the heating and release thermal process, the maximum temperature standard deviation of each temperature measurement point is 28.3 °C and 59 °C, respectively. The correctness of the thermal calculation of the EHSTSS is thus verified.

Application of Water Circulation Electric Heating System in Energy-saving Treatment of Floor Heating

Li, L. and Hong, Y.F., 2020. Application of water circulation electric heating system in energy-saving treatment of floor heating. In: Guido Aldana, P.A. and Kantamaneni, K. (eds.), Advances in Water Resources, Coastal Management, and Marine Science Technology. Journal of Coastal Research, Special Issue No. 104, pp. 385–389. Coconut Creek (Florida), ISSN 0749-0208.In the heating process of the current heating system, the temperature fluctuation range is large, the heating stability is poor, the heating power consumption and the heating cost are high, and the application research of the water circulation electric heating system in the energy-saving treatment of floor heating is proposed. This article takes AT89C51 single-chip microcomputer as the core, uses LCD, system clock, input/output parallel interface 8255, keyboard circuit, watchdog circuit, actuator and alarm circuit to realize the system hardware design. Using modular programming method, the system application program is divided into program modules, using assembly language programming, designing program modules, and realizing system software design. The system uses nano-material heaters and uses single-chip microcomputers to perform parameters such as water temperature, water level, and room temperature. Detection and protection of over-temperature, water shortage and electric leakage. Taking the single building of the green farm house experience center as an example, the research results show that the temperature fluctuation of the main indoor room heated by the water circulation electric heater system designed in this paper is small, the heating system heating stability is good, and the heating can be effectively reduced Power consumption, reducing heating costs.

Optimization of Energy Efficiency and Environmental Comfort in Broiler House

The objective of the study was to develop a design methodology involving a mixed system for better use of natural lighting and ventilation, together with electrical heating and ventilation systems that are currently used in commercial aviaries. Two building models were analyzed, one open conventional, and the other developed specifically for this study, with a cross ventilation brise-soleil system that provided greater energy efficiency in aviaries. Subsequently, the two models were compared using Autodesk’s Revit software through the Green Building Studio, to analyze the energy consumption of buildings during the year. The results showed that the model of poultry developed for the study proved to be more efficient in relation to the model of open poultry. The proposed broiler house was 21.07% more efficient than the conventional open aviary.

New anti-friction aluminum alloys for cast monometallic plain bearings. Bench tests

The work was carried out with the financial support of the Ministry of Education and Science of the Russian Federation under the Agreement No. 074-11-2018-011 of May 31,2018 on the topic: "Development and organization of high-tech production of innovative electric heating systems for inter-industry use with breakthrough performance" in the framework of the implementation of the RF Government decree No. 218 dated April 09, 2010. The article presents aluminum antifriction alloy from a series of newly developed alloys to replace bronzes for monometallic plain bearings. Complex alloyed aluminum alloys are developed using methods of nonequilibrium thermodynamics and the theory of selforganization. According to the results of applying nonequilibrium thermodynamics and the theory of self-organization to the friction process, the wear rate of rubbing bodies can decrease several times as the self-organization passes through the tribosystem and dissipative structures form. Complex alloying facilitates self-organization. Self-organization is determined by the intense occurrence of physicochemical processes with negative entropy production, i.e. such processes proceed in the direction of increasing free energy. Self-organization is expressed in the formation of the necessary secondary structures. The complexity of the system in our case was increased due to an increase in the complexity of antifriction materials, i.e. increase in the number of alloying elements. The results of the study of secondary structures on the friction surface of antifriction aluminum alloys are presented. The differences in the compositions and microstructure of secondary structures from the composition and microstructure of the alloy to friction are shown. The role of various chemical elements in the formation of the necessary secondary structures is discussed. Chemical elements could get into secondary structures from an antifriction alloy, steel counterbody, lubricant, atmosphere. The mechanical and tribological properties of aluminum alloys are determined. The properties of aluminum alloys with bronzes are compared. Aluminum antifriction alloys, inferior to bronzes in mechanical properties, significantly surpass them in tribological properties. Aluminum alloys are 6 times smaller than bronze, wear a steel counterbody; the load of the seizure of aluminum alloys is 2.5 times the load of the seizure of bronze; the wear rate of aluminum alloys is 2 times less than the wear rate of bronze. A pilot batch of monometallic plain bearings was manufactured from the new alloy and bench tests were carried out for comparison with bronze bearings. The bench test results confirmed the advantages of aluminum alloy over bronze, given that the lubrication and cooling conditions of aluminum bearings were more stringent than the conditions for lubricating bronze.

ТЕХНОЛОГИЯ МЕХАНИЗАЦИИ СОРТИРОВКИ ЛИЧИНОК GALLERIA MELLONELLA L.

In the modern world, insects are widely used for scientific and industrial purposes. For their cultivation in the laboratory, various plants have been developed, the main disadvantage of which is poor-quality sorting from garbage. Therefore, the question of cultivating and sorting the larvae of bee moth (Galleria mellonella L.) in laboratory conditions for the purpose of further use as a model object in various fields of biological sciences and medical purposes is relevant. The effect of the temperature gradient and exposure on the movement of G. mellonella larvae from the heated compartment of the plant was determined by their reproduction into the cold by the number of individuals that moved for 10, 15, and 20 minutes at 35, 40, 45, 50, 55 0С, visual counting. At 35 0С, regardless of the exposure time, the larvae remained on a honeycomb frame; at 40 ° C and 45 0С, on average, 11.5% and 31.8% of individuals, respectively, moved. The higher the temperature gradient, the faster the larvae moved into the cold compartment. More larvae passed from the lower frame to it than from the upper one. The difference at a temperature of 45 ° C averaged 2%, 50 0С - 18.7%, 55 0С - 0.4%. The optimum temperature gradient for sorting larvae is 50 ... 55 0С during an exposure of 15 ... 20 minutes, in this case more than 98% of the larvae were transferred to the cold compartment. The use of an infrared electric heating system will optimize the breeding process of G. mellonella larvae and ensure their high-quality sorting

Numerical simulation of the heat transfer process in the antiicing heating system for Arctic marine applications

In the Arctic, there is a serious problem of icing of structures, which can cause a catastrophic disruption of the functioning of the equipment necessary to maintain the life support of sea vessels and ground structures. For marine vessels, this problem is especially relevant in view of the limitations on heating systems and the mass of permissible heating equipment. The article is a continuation of work on the research and development of an electrical heating system for the air intake grilles of marine vessels. A numerical simulation of the heat transfer conditions for the design of the air intake grille with a built-in electric heating system was carried out. Some variant calculations of the numerical simulation of heat transfer processes in the system are presented — air, a streamlined structure — an air intake grill case — a heating system. A technique has been developed for selecting the optimal parameters of the electric heating system for various operating conditions of air intake grilles.

Interval optimal scheduling of integrated electricity and district heating systems considering dynamic characteristics of heating network

Coordinated operation of integrated electricity and district heating system (IEDHS) has great potential to enhance the flexibility of the power system to cope with the wind power curtailment. This study proposes an interval optimal scheduling algorithm for IEDHSs, considering the dynamic characteristics of the heating network. The model of the district heating system with dynamic characteristics including transmission delay and heat losses, is established in detail, and the uncertainties of both wind power and electricity and heating loads are described with interval numbers. Then an interval optimal scheduling model of the IEDHS is formulated to minimise the IEDHS operation cost. The impacts of the transmission delay and heat losses of the heating network on the scheduling of the IEDHS are analysed. Case studies are performed on the PJM 5-bus electricity system with a 6-node district heating system and IEEE 39-bus electricity system with a 12-node district heating system to evaluate the effectiveness of the proposed model. The results demonstrate that the dynamic characteristics of the heating network can integrate more wind power and enlarge the width of the cost interval.

Manufacturing and Performance Analysis of Q390A High-Strength Steel V-Shaped Stiffeners via Warm Drawing Process

Herein, warm drawing technology assisted by an electric current heating system is proposed to minimize the formation of wrinkles and cracks on the surface of Q390A high-strength steel V-shaped stiffeners during cold forming. V-shaped stiffeners with excellent properties were obtained by elevating the forming temperature and improving the material plasticity. The influence of temperature and tensile rate on the mechanical properties of the Q390A high-strength steel at 400-800°C was investigated. The effects of blankholder force and friction coefficient on the formed parts were simulated and analyzed by the finite element simulation software DYNAFORM. The law of heating and cooling for the formed parts during the forming process was studied through the electric current heating experiments. The forming temperature was controlled from 530 to 720 °C as the current density was maintained in the range from 7.3 to 8.5 A/mm2. Surface oxidation, cracks, sheet warping degree, sectional thickness distribution, mechanical properties, and microstructure of the V-shaped stiffeners formed at 400 to 700 °C were analyzed. The results show that the V-shaped stiffeners formed at 600 °C possess excellent overall properties.

A Customer-Centric Approach to Bid-Based Transactive Energy System Design

This study demonstrates how bid-based transactive energy system designs can be formulated from a customer-centric vantage point to encourage voluntary customer participation. Supportive evidence is provided for distribution systems populated by households with smart electric heating, ventilation and air conditioning systems. The optimal form of a household’s bid function is first derived from dynamic programming principles, based solely on the household’s general thermal dynamic and welfare attributes. The quantitative form of this optimal bid function is then explicitly derived, given quantitative forms for these attributes. A method is also developed for the systematic construction of household types based on these attributes. Bid comparison, peak load reduction, and target load matching test cases conducted for a 123-bus distribution system illustrate the usefulness of these methods for ensuring bid-based transactive energy system designs are able to align system goals and constraints with local customer goals and constraints.

Energy-saving technologies in the operation of oil fields

The analysis of peculiarities for functioning of the enterprise aimed at the development of an oil field located in the Arctic zone of Russia is presented. The specific energy consumption for oil and oil-containing liquids production, preparation and transportation of a marketable product are identified. Based on the assessment of the facility’s energy systems condition and world experience in the field of energy saving in the operation of oil fields in severe northern conditions, the used and potential energy-saving technologies have been analyzed. A more complete use of the energy of associated petroleum gas, taking into account its significant contribution to air pollution, based on the utilization of exhaust gases heat, will reduce heat pollution and excessive diesel fuel consumption in boiler houses for facility heating. From the point of view of increasing energy efficiency of the heat supply system, it is proposed to increase the heat-shielding performance of facilities, in particular the rotational field camp, the use of modern automated heat points with weather control. According to the study results, when generating electricity with the use of a gas-turbine drive, a non-regenerative cycle is used accompanied by releasing high-temperature exhaust gases. It is proposed to use gas turbine units with a regenerative cycle during the development of oil fields and to consider the possibilities for using a combined cycle. To increase the energy efficiency of pumps responsible for the formation pressure increase and oil transportation systems, it is recommended to implement a variable frequency drive. To reduce inefficient energy consumption, it was proposed to install additional temperature sensors in the electrical heating system for oil pipelines. As well as the possible options for energy consumption reduction through the use of wind generators, cogeneration based on solar energy and heat pumps are described.

The development of baking technology for bulk materials based on the use of alternative electric furnace

The article based on the experimental data and it describes the development of a rational design of an oscillatory system for controlled vibrational feeding of bulk materials during their heat treatment in furnaces with a vibratory base plate, which, together with the moving trolley on elastic connections, is the basis to transfer bulk material in the thermal field of an electric heating system with set processing time. To create nonsymmetric oscillations and to obtain unidirectional material motion at the horizontal furnace position, the conical springs are used. They should provide a gently inclined resonant peak, which can significantly reduce the sensitivity of the oscillating system to fluctuations of the natural frequency and excitation frequency, stiffness, friction and other factors under high temperatures and instability of the electrical network. However, the total elastic characteristic of the oscillatory system which is obtained as a result of the experiments consists of conical and cylindrical springs and shows a weakly expressed nonlinearity. Therefore, to achieve a transport effect it will require the installation of the entire furnace unit at an angle to the horizon. According to the available experimental data, a linear model of the oscillatory system was utilized.

Modeling of regional electrical heating load characteristics considering user response behavior difference

The load characteristics of “coal-to-electricity” based on demand response are affected by the users’ diversified demand and differential response behavior. Therefore, to describe the response behavior of different users in detail, a regional electric heating system load characteristics modeling method considering the dual difference of demand and response behavior is proposed. Firstly, considering the users’ characteristics and external environmental factors, a thermal comfort temperature model of differential users is proposed. And a thermal load characteristics modeling method is proposed based on the air temperature time-varying equations of buildings. Secondly, a multi-objective optimization method and a decision-making method are used to simulate the differential response behavior of users to obtain the load characteristics of a single class of users, which based on the discrete selection model. Finally, the regional users’ classification criteria are established, which based on the influence factors of heat demand and response behavior. And the modeling method of multi-type users aggregate load characteristic is proposed. At the end of this paper, case studies of the modeling method have been validated the effectiveness of improving the solution accuracy of load characteristics.

The Modeling of the Electric Heating and Cooling System of the Integrated Energy System in the Coastal Area

Zuo, X.; Dong, M.; Gao, F., and Tian, S., 2020. The modeling of the electric heating and cooling system of the integrated energy system in the coastal area. In: Yang, Y.; Mi, C.; Zhao, L., and Lam, S. (eds.), Global Topics and New Trends in Coastal Research: Port, Coastal and Ocean Engineering. Journal of Coastal Research, Special Issue No. 103, pp. 1022–1029. Coconut Creek (Florida), ISSN 0749-0208.The accurate analysis of the coupling relationship of the electric heating and cooling system is the basis of its load calculation. Because the current method does not consider the analysis of the coupling relationship of the electric heating and cooling system in the design, the accuracy of the load calculation results is low. In order to solve this problem, the load modeling of the electric heating and cooling system of the comprehensive energy system in the coastal area is studied. Through the calculation of power network, natural gas network and comprehensive energy flow, the power flow value of electric heating and cooling system of comprehensive energy system is obtained. On this basis, according to the energy conversion efficiency of the equipment included in the energy hub and the distribution ratio of electric energy and gas, the coupling relationship of the electric heating and cooling system is obtained. According to the coupling relationship of the electric heating and cooling system, the load model of the electric heating and cooling system is constructed, and the optimal solution of the model is calculated by Grey Wolf algorithm to complete the modeling research of the electric heating and cooling system of the comprehensive energy system in the coastal area. The simulation results show that the model designed in this paper can obtain the accurate calculation results of the active power and reactive power of the electric heating and cooling system, and the calculation of the load of the electric heating and cooling system is time-consuming, accurate and reliable.

Operation strategy of cross-season solar heat storage heating system in an alpine high-altitude area

The full use of renewable energy sources such as solar energy to meet the various energy supply needs of buildings is now a research focus and an industry development trend, as energy consumption has been increasing and environmental pollution has become a serious problem. In the high-cold and high-altitude area in western China, due to the abundant solar energy and hydropower resources, the use of electric auxiliary cross-season solar heat storage heating system (CSHSHS) is an effective way to achieve clean heating. In this article, the authors applied a CSHSHS in a typical town in the Sichuan West Plateau and analysed and compared three operation strategies: heating storage priority control mode; electro-thermally assisted priority control mode and hybrid control mode. The results show that the heat storage priority control mode would require a large installed capacity of electrical auxiliary heat. The power consumption of the electro-thermally assisted priority control mode is high. The hybrid control mode can effectively reduce the installed capacity of the electrical auxiliary heat and the power consumption in the heating season. The solar fraction of the hybrid control mode was 38.29%, which has an obvious advantage. The results are of great engineering significance for optimizing the operation strategy of CSHSHS.

Performance and economic evaluation of a photovoltaic/thermal (PV/T)-cascade heat pump for combined cooling, heat and power in tropical climate area

• A new approach on PV/T and cascade heat pump design for generating electricity, heating and cooling. • Cool and hot water could be used for building cooling and hot water drying processes. • Some part of cool water generated by heat pump is used to reduce the PV/T module temperature and enhances the PV/T power generation. • An approach of sizing PV/T module, hot and cool water storages matching with the heat pump for simultaneous heating and cooling under tropical climate. Performance analysis of a new PV/T-cascade heat pump design having 7-kW maximum cooling capacity for combined cooling, heat and power was simulated with the climate of Chiang Mai, a city in tropical area. The technique could enhance both electrical performance of PV/T module, and heat pump thermal performance for cool water (below 17°C) and hot water (80-90°C) generations. Part of the cool water generated by the heat pump was used to cool down the PV/T module temperature and increase the PV/T generated electrical power. In addition, the heat from the PV/Ts became additional cooling load of the heat pump then the cooling and heating capacities of the heat pump could be increased. The unit was used to replace the existing units, a hot water electrical heating system and a vapor-compression chilled water system. With the electrical power generated by a set of PV/T modules, the new unit could save the grid electrical consumption significantly. From economic assessment with 10-hour daily operating time (7:00-17:00), the suitable PV/T module number each of 200 Wp (peak power) was found to be 7. It could also be found that 23.76 × 10 3 kWh e of the annual grid electrical energy was saved and the payback period of the unit was 7.87 years.

Optimal scheduling of gas and electricity consumption in a smart home with a hybrid gas boiler and electric heating system

Space and water heating are two major components of household energy consumption, and a number of work has been done to combine multiple residential heating technologies to develop hybrid heating solutions that are more flexible, efficient and economical. This paper studied and modelled a smart home with a novel hybrid heating system, which consists of a wall-hung gas boiler (for both space and water heating) that is connected to a water tank with an auxiliary electric resistance heater (for water heating), and auxiliary split air conditioners (for space heating). A multi-objective optimization was further formulated to optimally schedule the gas and electricity consumption of a smart home equipped with the hybrid heating system as well as an onsite photovoltaic (PV) system, a battery energy storage system, an electric vehicle and various types of flexile loads. Two objectives, i.e. the minimization of operating energy cost (including both electricity and gas payment) and the maximization of thermal comfort, were considered. The optimization problem was finally transformed to a single objective mixed integer linear programming problem that can be solved by existing optimization solvers. Simulation results verified the operational performance of the studied hybrid heating system and the effectiveness of the proposed scheduling method. Sensitivity analysis was conducted considering various levels of electricity/gas prices, onsite PV capacity, battery capacity and outdoor air temperature, and it shows that in all the scenarios the operating energy cost of the smart home with the hybrid heating system was always lower than that with the pure electricity or pure gas heating systems. The performance under various uncertainties and the benefits of adopting model predictive control were also demonstrated. It is noted that this paper only focuses on the optimal scheduling and operation costs of the hybrid heating system. Optimal configuration and sizing of the heating system with the initial investment (i.e. capital expenditures) considered are identified as research directions in the future.

Integration of heat pipe solar water heating systems with different residential households: An energy, environmental, and economic evaluation

This study presents a detailed methodology for evaluating the energy, environmental, and economic contributions of heat pipe solar water heating (HPSWH) systems in various households. The hot water consumption patterns of Perth residents in Australia in one, two, and four-occupant houses are extracted in hourly basis throughout a year. The annual performance of the system is evaluated based on parameters such as saved energy, solar fraction, avoided CO2 emission, saved money, and payback period. Moreover, an experimental rig is designed, manufactured, and tested. The results show that the contribution of the solar system in meeting the hot water demand is around 99% in summer, while this contribution drops to 36–51% in winter. Almost 387–1146.8 kg of CO2 emissions can be avoided annually in Perth if HPSWH systems are integrated with the conventional heating systems. In addition, it is shown that the HPSWH system has its most economic justification in households with higher number of occupants. Moreover, the payback period is much lower for houses with conventional electric water heating systems compared to houses with LPG systems.