Electric Heating Research Articles

A method for evaluating the regulation capacity of thermostatically controlled load group based on state complementary control strategy

Electric heating load (EHL) is a type of thermostatically controlled load whose power consumption mode can be flexibly adjusted, as long as the customers’ thermal comfort is ensured. The key to unlocking the regulatory potential of EHL lies in characterizing and harnessing its post-aggregation regulatory capacity, given its inherent dispersion and heterogeneity. Firstly, the second-order equivalent thermal parameter (ETP) model, grounded in the thermal equilibrium of the room, is employed to analyze the operational characteristics and to construct a model for aggregating load group. Secondly, leveraging the analysis of individual EHL regulation capacity, the temperature state characteristic quantity is introduced as a sorting index. Considering the dynamic properties of baseline power over time, a control strategy is proposed, based on state complementary characteristics among EHLs, for a more comprehensive and dynamic system management. Finally, the key indexes for reporting and implementation phases are identified to evaluate the regulation capacity of load group. The case study evidences that the newly introduced control strategy and evaluation method can provide more stable regulation power support for power grid dispatching, and more deeply harness the regulation capacity to maximize its potential value. In addition, this paper also discusses the influence of related factors such as the number, the rated power, the inside temperature control interval, the inside temperature setting value and the outside temperature on the regulation ability of the EHL group, offering a robust framework for the dispatching center to devise well-informed and rational regulation instructions.

Entropy analysis of mixed convective electro-magnetohydrodynamic couple-stress hybrid nanofluid flow with variable electrical conductivity in a porous channel

The paper presents a novel study to examine the irreversibility of quadratically mixed convective electro-magnetohydrodynamic (EMHD) flow of a couple-stress hybrid nanofluid (CSHNF) with variable properties in a vertical porous channel. The channel walls are exposed to an applied electric field effect and a uniform transverse magnetic field. The hybrid nanofluid considered is an ethylene glycol (C 2 H 6 O 2) base mixed with multi-walled carbon nanotubes (MWCNT) and silver (Ag) nanoparticles (NPs), assuming the base fluid and nanoparticles to be in a state of thermal equilibrium following the Tiwari-Das nanofluid model. The potential applications of the study can be in microfluidics to nanofluidics, particularly in developing cooling technologies, EMHD pumps, high-end microelectromechanical systems (MEMS), and lab-on-a-chip (LOC) devices used in bioengineering. A constant pressure gradient acting in the flow direction and the buoyancy effect under the quadratic Boussinesq approximation drive the flow. The governing momentum and energy equations are nondimensionalized using pertinent dimensionless parameters and solved by the semi-analytical homotopy analysis method (HAM). The entropy generation and the Bejan numbers are derived to examine the irreversibilities in the system. To investigate the rate of shear stresses and heat transfer, skin friction coefficients and Nusselt numbers on the channel walls are determined. The analysis emphasizes the influence of nanoparticle concentration and electromagnetic field on the flow dynamics, temperature distribution, and system irreversibilities in the presence of porous media. It reveals the enhancement of fluid velocity and temperature degradation for higher concentrations. In contrast, both reduce for higher magnetic and electrical strength. With the enhancement of electrical joule heating and quadratic convection, a higher entropy generation rate is attained with a low rate of heat transfer irreversibility. However, it reduces with higher nanoparticle concentration, electrical strength, porosity, and variable electrical conductivity parameters under the dominance of heat transfer irreversibility.

Comparison of Conventional and Microwave Heating

Carnot batteries (or Power-to-Heat-to-Power systems) are capable of increasing the use of electricity from photovoltaic or wind power plants to achieve decarbonisation of the electricity sector. To decouple electricity production from demand, these renewable power plants can be connected to the thermal energy storage system of a concentrated solar thermal power plant via electric heaters. As an alternative to electric heaters, microwaves are studied as a volumetric and selective heating method, avoiding the limitations of the Joule effect conventional heating when having solar salt (non-eutectic mixture of 60 wt % NaNO3 and 40 wt % KNO3), which is a storage medium with low thermal conductivity, working at a temperature very close to its affordable maximum temperature without degradation. In this work, the two heating methods are compared both experimentally and numerically. At experimental level, a microwave oven and a muffle furnace are used to record energy consumption and time for a common objective. Additionally, different crucible materials were used to test their suitability with microwaves. Only quartz glass was validated for microwave heating, while the porcelain and alumina based materials (Corundum and Alsint 99.7) failed while exposed to microwaves. Compared to conventional heating, heating solar salt with microwaves saved fifty minutes of time and ninety percent of consumption. These experiments were validated by numerical simulations, showing a different distribution in each experiment.

Analysis of CSP/PV Hybrid Power Plants in High Latitude Regions

This study aims to explore the potential of combined CSP and PV systems in high latitude areas. Several performance metrics are evaluated and compared with standalone CSP or PV plants to identify the benefits and challenges of deploying such hybrid plants. Six different sites have been selected and the ASDELSOL hybrid power plant simulation tool, developed by the Thermodynamics and Renewable Energies Group at the University of Seville, has been used. This simulation tool allows performing dynamic performance simulations of hybrid solar plants under various operation strategies, along with conducting economic evaluations. We have analyzed a hybrid solar plant composed of 50 MW PTC and 75 MW PV, with 10 hours of TES and a 15 MW electric heater to transfer excess PV energy to the TES tanks in a 50 MW base load operation strategy, where the main objective of the PV plant is to cover the self-consumption of the PTC plant. Results obtained show that PV/PTC hybridization reduces LCOE and increases CF compared to standalone PV or PTC plants. These improvements are more pronounced in regions where the contribution of PTC plants is lower. In high latitude regions, an N-S orientation of PTC fields achieves higher production than an E-W orientation. However, a combination of both orientations can optimize their production and performance. Finally, it is concluded that it is necessary to carry out feasibility studies in high latitude locations before dismissing them outright, as it has been observed that, in certain regions, hybrid PV/PTC solar plants can offer an effective alternative.

Numerical investigation of high temperature heat pump integrated hybrid cooling system

Over 67 % of the energy demand within the pharmaceutical and semiconductor industries is for their cleanrooms, driven by stringent temperature and humidity control requirements. Despite high energy usage, heating, ventilation, and air-conditioning (HVAC) units consisting of conventional vapor compression systems (CVCS) are favoured for their simplicity. Hybrid cooling systems (HCS) offer potential efficiency gains by separating latent and sensible loads. Still, reliance on fossil-fuel-fired or electric heaters to regenerate the desiccant makes it energy intensive and reduces CO2 mitigation benefits. This study explores high-temperature heat pumps to simultaneously cool process air and heat regeneration air, thereby using multiple benefits. Heat pumps with condensing temperatures of 80 °C, 90 °C, and 120 °C and an ejector-enhanced trans-critical CO2 heat pump were compared with CVCS and HCS. The 120-bu and CO2HP configurations demonstrated a system COP of 2.94 and 3.22, respectively, surpassing CVCS, which has a system COP of 1.44. These setups achieved CO2 emission reduction of 51 % and 55.2 %, compared to CVCS, respectively.

Impact of space utilization and work time flexibility on energy performance of office buildings

This study investigates the impact of different space utilization on energy use intensity, heating load, cooling load, and thermal comfort of occupants using a combination of empirical data gathering and simulation-based studies. The increasing worldwide preoccupation with energy consumption and environmental sustainability has led to increased attention on optimizing interior spaces to mitigate total energy demand. The considered case study for conducting this research was the Norwegian living lab namely Zero Emission Building (ZEB) Flexible Lab in Trondheim, Norway. In this study, 10 different scenarios of occupancy schedules based on flexible arrangements from standard workweeks to extensive remote work configurations were designed and analyzed using IDA ICE 5.0. The findings demonstrate significant reductions in energy use across scenarios with increased teleworking and compressed work weeks. The remote scenario achieved the most significant decrease in Energy Use Intensity (EUI), with a reduction of 46 % compared to the base case. Similarly, the implementation of flexible hours and remote working in scenarios resulted in a reduction of electric heating demand by up to 23 %, underscoring the potential of occupancy-based strategies in enhancing building energy efficiency. However, uncomfortable hours increased by 59 % in the 2-day remote working scenario compared to the base case, demonstrating the need to consider climate conditions when implementing remote work. The research offers valuable insights into the complex connections between flexible arrangements and energy efficiency, considering many elements such as occupancy schedule and use dynamics. This article offers a comprehensive analysis that may give architects, building managers, and policymakers valuable insights. This study contributes to the developing sustainable architecture by emphasizing the impact of dynamic occupancy on the energy performance of office buildings.

The impact of surface metallization on multilayer carbon nanotubes regarding the operational characteristics of composite electric heaters utilized for anti-icing protection

The design of energy-efficient heating techniques is emerging as a crucial scientific and technical challenge, driven by the growing focus on the advancement of the northern regions of the country, particularly the Arctic. Research in Arctic materials science, which incorporates cutting-edge techniques from various interdisciplinary fields like nanotechnology and electrotechnology, could become a key area of study for the development of these northern regions. The development of an electric heating composite material that utilizes an organosilicon elastomer as the polymer matrix and metallized multilayer carbon nanotubes (MWCNTs) serving as a conductive filler with enhanced resistance to icing enables an efficient electrothermal anti-icing system The paper presents the results of the study of an electric heater based on the wiring of an elastic composite with the effect of temperature self-regulation. For modification of the silicon-organic compound, metallized MWCNTs were used, which increased the sensitivity of heating elements to ice formation. When the ambient temperature decreases, the polymer composite has different values of electrophysical parameters, which create the effect of acceptable electrical heating concerning the ambient temperature. The research results have significant practical value, as the heating elements can have different compositions and can be operated at low temperatures. Heating elements can effectively adjust the heating mode to the ambient temperature conditions, saving electrical energy. The heating time required for the ice to melt is 210 seconds, and the dynamics of the current consumption value correlate with the ambient temperature, reflecting the effect of temperature self-regulation.

A Novel Electric Vehicle Thermal Management System Based on Charging Station Heat Pump System During Fast Charging

Abstract A battery thermal management system based on a charging station heat pump system is proposed to improve battery charging efficiency during high-power DC charging. The system provides coolant of appropriate temperature through the charging station heat pump system. It enables the battery to be charged at the optimal temperature for charging, which improves the charging efficiency and reduces the charging time. The two system models are modeled and analyzed using numerical simulation software, and the temperature characteristics and charging time of the proposed system and the original battery thermal management system based on the electric vehicle heat pump system are analyzed under five different temperature conditions. The results show that the proposed system has fast response, high efficiency, and can maintain the maximum temperature below 50°C. Compared with the original system, the proposed system reduces the charging time of the power battery by 10.6%, 17.9%, and 24.6% at 0°C, −10°C, and −20°C operating conditions, respectively. It also saves 1.4% and 6.0% of the charging time at 20°C and 40°C operating conditions, respectively. Comparing the charging time for the power battery at each stage, the proposed system mainly reduces the charging time in the range of 0-20% of the battery state of charge compared to the original system.

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.

Chaotic self-beating of left ventricle modeled by liquid crystal elastomer

Self-vibration systems using active materials generate sustained vibrations spontaneously through synergistic actions between internal structure and external environment. Therefore, the self-vibration systems have a wide application prospect in bionic design and soft robots. Inspired by the human left ventricle, a novel chaotic self-beating system modeled by an electrothermal responsive liquid crystal elastomer balloon is proposed. To study the self-beating characteristics of the liquid crystal elastomer left ventricle, a simplified theoretical framework is formed by combining the electric joule heat conduction model, the left ventricle circulatory system model and the dynamic principle. The numerical results show that the left ventricle has two typical self-beating modes: periodic beating and chaotic beating. The mechanisms of periodic beating and chaotic beating are elucidated by analyzing the balance between the work done by each force on the left ventricle. In addition, the effects of key system parameters on self-beating behavior are investigated in detail. This research will promote the application of chaotic dynamics in artificial hearts and medical devices, while providing a new perspective for the study of chaotic behavior and mechanism in biology.

Influence of irregular fiber filling on the performance of hollow fiber membrane modules for cold water production

The countercurrent hollow fiber membrane-based evaporative water cooler (MEWC) offers an eco-friendly and compact solution for cold water generation. This study introduces a random sequential addition algorithm to model the real-world irregular fiber filling within the MEWC. Inspired by the honeycomb structure, the developed 3-D numerical model adopts a calculation unit featuring a hexagonal prism comprising multiple fibers. Validation against experimental data reveals an average relative error of 2.81 % concerning outlet water temperature. The effects of fiber filling patterns (regular layout and random layout) on the velocity and temperature fields of the MEWC are investigated. Comparisons of outlet water temperature, cooling efficiency, consumptive electric power ratio, and heat and mass transfer resistance composition between these layouts under various operating conditions are conducted. The results indicate that the random layout fosters severe channeling effect and large flow dead zones, impairing air side heat and moisture transfer. The random layout exhibits over 15.9 % reduction in cooling efficiency and 36.3 % decrease in consumptive electric power ratio compared to the regular layout. Irregular fiber filling leads to a notable 158.6 % increase in air side heat transfer resistance and a 35.9 % rise in mass transfer resistance. Although irregular filling compromises the cooling performance, it demonstrates potential for energy savings under certain conditions. Design schemes should be carefully tailored to meet specific application requirements by considering these trade-offs.

Vibration reduction of an electric vehicle heat exchanger by controlling the polarization of its ferroelectric ceramics

The growing requirements in terms of CO2 emissions reduction in transports renders necessary the development of new electric traction technologies. This results in new technical constraints for equipment manufacturers, forcing them to reduce the acoustic emissivity of their new products inside and outside vehicles. Heat exchangers for electric cars are part of this new product category. High voltage supplied by the battery of electrical vehicles requires introduction of a new energy conversion process and technology. To this end, components based on ceramics containing barium titanate (BaTiO3) with high electrocaloric coupling properties are selected to provide the heating function. Baryum titanate is ferroelectric. This category of materials is subjected to piezoelectric and electrostrictive effects. The vibrations induced in the components (rods) containing the BaTiO3 ceramics are transmitted through the system, and cause undesired acoustic radiation. This coupling is a suffered effect and is not taken into account in the integration process during the rods manufacturing. In this study, an experimental characterization is proposed to identify the involved electromechanical coupling coefficients. Numerical simulations of the vibrations induced by BaTiO3 are carried out and used to study the possibility of attenuating them by controlling the polarisation of the ceramics or by geometric modifications.

ASSESSMENT OF GEOMETRIC DISTORTION OF CANTILEVERS PRINTED WITH DIFFERENT INTERNAL STRUCTURES AFTER DIFFERENT POST-PROCESSES

This study assesses the geometric distortion of cantilevers fabricated from stainless steel 316L with varying internal structures using Selective Laser Melting (SLM) technology. The cantilevers were printed under identical conditions and subsequently post-processed with Wire Electrical Discharge Machining (WEDM) and heat treatment. The geometric deviations were evaluated using a micrometer and a Coordinate-Measuring Machine (CMM). This research underscores the importance of internal structure selection and post-processing in enhancing the geometric accuracy and mechanical stability of 3D-printed slender structures from stainless steel. By demonstrating that internal geometries can significantly influence the end product's structural performance, the findings provide valuable insights for the design and engineering of Additive Manufactured (AM) components, particularly in applications that involve bending.

Towards sustainable hydrogen production: Integrating electrified and convective steam reformer with carbon capture and storage

This work reports the design of a process for hydrogen production based on electrified steam methane reforming (e-SMR) coupled with a convective reforming (convective SMR) and carbon capture and storage (CCS) as an alternative to conventional fuel-fired reforming to reduce natural gas (NG) consumption as well as carbon dioxide emissions. The energy required by the reforming reaction is supplied by direct electric heating instead of burning fossil fuel in the radiant section of a furnace, saving 35 % NG and reducing CO2 emission by 29 %. Implementing convective SMR reduces the electric load of the main e-SMR reactor and ensures a slightly higher thermal efficiency (80.2 %) compared to conventional fuel-fired reforming (78.9 %). Further CO2 emissions (85 %) and NG consumption reduction (50 %) are possible by adopting amine-based CO2 capture. If coupled with an energy integration scheme, it is possible to capture 75 % of the CO2 produced, preserving high energy efficiency (79.4 %). This requires only a 14 % increase in capital costs, which is strongly beneficial compared to applying CO2 capture to flue gases of the fuel-fired reforming (69.8 % efficiency and 80 % more capital costs).The process based on e-SMR coupled with convective SMR and CO2 capture ensures a levelized cost of hydrogen (LCOH) of 0.281 € Nm−3 H2, which is much lower than the conventional fuel-fired reforming with CO2 capture applied to flue gases (0.309 € Nm−3 H2). Moreover, it has comparable CO2 emissions (1.59 vs 0.99 kg CO2 emitted kg−1 H2) but produces lower CO2 (6.39 vs 9.88 CO2 produced kg−1 H2) compared to fuel-fired reforming due to using renewable electricity as energy source for the SMR. Compared to conventional fuel-fired reforming, the same process provides similar LCOH (0.283 vs 0.282 € Nm−3 H2) but with drastically lower CO2 emissions (1.59 vs 8.99 kg CO2 emitted kg−1 H2).

Integrating solid oxide electrolysis cells and H2-O2 combustion for low-emission high-temperature heating with heat pump in the chemical industry

Low-emission high-temperature heating could be achieved by exploiting electrical heating, clean fuel, or carbon capture. However, it is difficult to replace current coal or natural gas furnaces in some places because the high-temperature thermal demand needs combustion. In the present work, the green hydrogen production process by solid oxide electrolysis cells (SOEC) and H2-O2 combustion is integrated into ethylene production. The working conditions of electrolyzer and furnace are analyzed. The SOEC should work over 800°C to keep endothermic state no matter the current density. To produce the hydrogen of 80 MW heat value, the electric consumption is at least 69.4 MW. With the high-temperature waste heat of 7.76 MW, an additional 3 MW power is required for water electrolysis. The heat released during condensation of combustion products is 30.52 MW, much higher than 13.19 MW from SOEC products. Therefore, the heat pump is necessary to recycle the waste heat of water condensation and generate steam as the electrolysis ingredient and cooling medium, which saves 63 % of energy. Although the total energy consumption increases by 11.23 % from 80.23 MW to 89.24 MW, the CO2 emission drops by 84.28 %.

Frost-resistant embankments with a novel ground source heat pump system

This study introduces a novel artificial heating technique aimed at addressing frost heave issues in embankments on frozen ground, offering a sustainable solution. Initial evaluations assessed various heating systems, including boilers, heat pumps, solar heaters, and electric heaters, focusing on their thermal performance and applicability. The study subsequently designed and implemented a direct-expansion ground source heat pump (DX-GSHP) system as the primary heat source for embankment warming. Rigorous testing confirmed the DX-GSHP system's ability to maintain a heat-supply temperature above 40 °C and a heat-absorption temperature below −3.5 °C, effectively extracting geothermal energy for transfer to the topsoil layers. With a demonstrated coefficient of performance (COP) of 3.49, the DX-GSHP system not only proves its energy efficiency but also suggests a potential role in reducing the strain on electricity supply systems. Installation of DX-GSHPs, with heating capacities ranging from 1.0–2.0 kW and spaced at intervals of 2.0–4.0 m, provides a rapid thermal response to frost heave in single-track railway embankments, thereby potentially mitigating frost-induced damage in cold climate regions.

Influence of supply temperature and booster technology on the energetic performance and levelized cost of heat of a district heating network with central heat pump

The development of new low-temperature district heating networks in existing urban areas can accelerate the replacement of fossil-fuel-based heating systems by collective heating using electricity or renewable heat sources. Buildings can either be connected to the network in their current, non-refurbished state for rapid deployment or be refurbished before connection to achieve maximum energy efficiency. To assess the difference between these two strategies, this paper examines eight low-temperature district heating concepts with central heat pump, comparing their energy use and levelized cost of heat. The study includes four scenarios for each strategy, considering supply temperatures ranging from 10 °C to 75 °C. Heat pumps or electric heaters are used as booster technology when the network supply temperature is too low for space heating or domestic hot water purposes. The use of booster heat pumps shows the highest seasonal coefficient of performance for both refurbished (4.61) and non-refurbished buildings (3.43). However, booster technologies result in the highest levelized cost of heat, driven mainly by the high investment cost of the network and booster units. Lowest levelized cost of heat of 213 €/MWhth is obtained for non-refurbished buildings at 75 °C and 297 €/MWhth for refurbished buildings at 55 °C without boosters.

Continuous and multicyclic sorption-based atmospheric water harvesting with heat recovery in arid climate

Nowadays, two-thirds of the global population are grappling with water scarcity. Sorption-based water harvesting (SAWH), which does not depend on conventional water sources and provides decentralized clean water, is steadily gaining popularity. However, the contradiction between the low daily water production in arid climates and the high energy consumption of large-scale devices has become a pivotal limitation for efficient water harvesting. Here, we report a multicyclic SAWH device with heat recovery equipped with 3 sorbent beds that alternatively desorb in automatic switching mode to achieve all-day continuous water harvesting. Furthermore, based on the rapid sorption and desorption kinetics of the adsorbent in the initial stages, employing a rapid-cycling operation strategy contributes to realize an outstanding water productivity of 8.07 kg day−1 and 0.21 kg kgsorbent−1 day−1 under practical arid conditions (15 °C/25 % RH). Besides, the apparatus equipped with heat regenerator showed a significant decrease in energy consumption from 12.17 kWh to 10.65 kWh during a desorption cycle (4 h). Moreover, a hybrid desorption mode driven by a combination of solar collector and electric heater is demonstrated in an island. This SAWH system is anticipated to provide a promising approach for large-scale efficient water harvesting in all-day arid regions (RH<35 %).

Water heater storage heat pump cycle for higher operating range

Heat pumps for water heating have become increasingly attractive. However, the achievable water temperature using a vapor compression heat pump water heater (HPWH) is often constrained by the compressor operating envelope. To address this challenge, HPWHs typically employ two-stage compression with complex system architecture or rely on back-up electric heating. This work introduces an alternate storage heat pump concept to improve the operating temperature range of an R134a HPWH system. The developed system operates in two modes: Mode I functions as a typical wrap-around condenser HPWH, while Mode II splits the wrap-around coil to use the top portion as a condenser and the bottom portion as evaporator. System modeling consisting of a vapor compression cycle and water tank sub-models was conducted to study the performance. The model was validated experimentally. The storage heat pump system could achieve an additional increase of 12 °C beyond the maximum possible water temperature of 46 °C which was achieved using the baseline conventional HPWH system. In Mode II, the system exhibits a 20 % higher average heating capacity and a 15 % lower average pressure ratio compared to the conventional system operating at a 27 °C ambient temperature. Compared to usage of electric heating elements, our system showed a longer recovery time with a 50 % lower energy consumption for a similar increase in water temperature.

Research and Application of Electromagnetic Heating Device for Digital Well Site Crude Oil Export

Abstract Most well sites have discontinued using the associated gas-fired furnaces in response to the current situation in the oil fields. Coal-fired heating furnaces are environmentally polluting and prohibited due to local environmental regulations. These two heating methods can cause high costs, poor heating efficiency, and environmental pollution, which cannot be achieved through remote digital monitoring. Research has been conducted on the digital electromagnetic heating device for crude oil in the well site, focusing on introducing its main components and functions, including the electromagnetic heating body, frequency conversion control cabinet, and digital remote monitoring terminal. This device provides one-way internal heating without a heat source, resulting in high thermal efficiency, safety, environmental friendliness, and energy conservation. It comprehensively addresses the drawbacks of traditional electric heating, characterized by low efficiency, susceptibility to damage, and difficult maintenance. In 2022, it was applied at three well sites in the Tongzhai operation area of the Third Oil Production Plant of Changqing Oilfield, replacing the existing gas-fired and coal-fired heating furnaces to heat crude oil, as well as heating the heating belt and various electric heating pipes. This device is highly efficient, safe, environmentally friendly, and energy-saving. Additionally, the temperature and pressure of electromagnetic heating crude oil can be digitally and remotely monitored.