Use Of Electric Heaters Research Articles

Pathomorphogenesis of Thermal Injury in Animals

In the practice of a veterinarian, it is not often, but you have to deal with various injuries and wounds in animals. Burn wounds heal especially hard in animals. And death often occurs from intoxication or septicaemia Physiological processes in the body of animals take place at a certain body temperature, which is peculiar only to a certain type of animal. Changes in the thermal parameters of the body lead to pathological changes. And a stronger increase or decrease in body temperature parameters can lead to death. Thermal injuries in animals can be caused by the action of open fire, boiling water, chemicals, ionizing radiation, as well as by improper use of electric heaters or insufficiently grounded plates of electric scooters. A thermal wound is a pathological process with a violation of the integrity of the skin, which leads to a decrease in the basic functions of the body, severe injury and death. The degree of tissue damage depends on the type of active damaging factor, its strength and duration of exposure. [5] Local infectious complications are very common in thermal burns. The resulting infection slows down the healing of burn wounds and contributes to the formation of scars [6]. The contamination of wounds with bacteria begins immediately after the burn and consists of conditionally pathogenic bacteria of the environment or the animal’s own biome.

Techno-economic optimization of molten salt based CSP plants through integration of supercritical CO2 cycles and hybridization with PV and electric heaters

The present study explores the integration of supercritical CO2 (sCO2) power cycles into Concentrating Solar Power (CSP) plants using molten salt, and the hybridization of these plants with solar photovoltaic (PV) systems through electric heaters. Techno-economic evaluations determined the optimal power cycle configuration and subsystem designs for two different scales and locations and then compared them with state-of-the-art solar power plants. The results show that hybridizing PV with state-of-the-art CSP can lead up to a 22% reduction in the Levelized Cost of Electricity (LCOE) compared to standalone CSP systems. This hybridization and the use of electric heaters are particularly beneficial for small-scale installations and locations with low DNI/GHI ratios. By replacing the steam Rankine cycle with a sCO2 power block, a further 42% reduction in LCOE can be achieved at small scales, even with a simple recuperated cycle. In conclusion, the hybridization with PV and the integration of sCO2 power blocks provide cost benefits despite the temperature limitations imposed by the molten salt. Hybrid PV-CSP plants with sCO2 power blocks prove to be a cost-effective solution for capacity factors exceeding 60%. For lower capacity factors, configurations combining PV with battery energy storage or PV with electric heaters, thermal energy storage, and sCO2 power blocks are preferable options.

Comparison of traditional district heating with low temperature district heating systems featuring organic Rankine cycle and heat pump

Paper presents a comparison between a traditional district heating system with conventional boilers as a source of heat and electricity purchases from power utilities and a low temperature DH system incorporating the CHP with organic Rankine Cycle providing electricity and local heat pump raising the temperature of the DH fluid to the required temperature in the dwelling, meaning that both heat and electricity are produced within the system. Additionally, such “island” system may feature or not the heat pump. Comparisons are made based on the results obtained using a developed simple analytical model enabling calculations of the efficiency of respective systems. The analyses have a general character and can be used in studies of complex networks however presented in the paper simple examples show merely the fundamental capabilities of the developed tool. The objective of the heat pump in the system is to increase temperature of hot water to the required level locally at the dwelling and provide the heating in such way, contrary to the traditional system, where water heating is considered by the use of electric heaters to increase parameters of water for central heating purposes and preparation of utility hot water. Presence of the heat pump in the system allows for significantly lower temperatures of distributed in the network heat carrier.

Approach of design of electric heaters used in non hermetically sealed structure spacecrafts

A design feature of the construction of electric heaters for non-pressurized spacecraft using a heating element in the form of a tape of a material with high resistivity, located on a flat base (electrical insulating substrate) in the form of a snake with the organization of the necessary gaps between the tapes, is revealed. A mathematical model has been developed for calculating the main design parameters of electric heaters: power, mass, heated surface area. The nomenclature of efficiency indicators used as optimization criteria has been formed: power utilization factor, filling factor of an electrically insulating substrate tape, surface density, energy-mass efficiency, thermal efficiency of heating, target efficiency. The methodological principles for ranking the requirements for the parameters of electric heaters are determined using the selected optimization criteria: the preferred use of tape materials with high resistivity and minimum thickness. A method is formulated for step-by-step calculation of the parameters of electric heaters in the presence of restrictions on the maximum heat flux density determined from the conditions for the use of electric heaters. General recommendations have been developed for choosing the parameters of electric heaters: use increased voltage, minimize the thickness of the heating element tape and the width of the gap between the tapes, determine the minimum value of the tape length for the maximum heat flux density at a given voltage rating.

Cooking, Heating, Insulating Products and Services (CHIPS) for Mongolian ger: Reducing energy, cost, and indoor air pollution

This project sought to answer three related questions about the Mongolian ger (ger are called yurt in Russian) assembled in the highly polluted, informal settlement areas called ger-districts. (1) Can replacing coal stoves with electric heaters in ger reduce indoor PM2.5 concentration? (2) What are the major causes of indoor PM2.5 concentration in ger? (3) Is it cost effective to heat ger with electric heaters? A year of testing insultation protocols in Ulaanbaatar was followed in the second year by the deployment of a package of “Cooking, Heating, Insulating Products and Services” (CHIPS) to nearly 183 ger in Bayankhongor, Mongolia. The results demonstrated that a better sealed and insulted ger could be heated with electricity less expensively than heating a typical ger with wood and coal. However, the use of electric heaters did not reduce indoor air pollution. The results showed that indoor pollution levels closely followed outdoor levels, with a small delay for air to infiltrate. The study suggests that to reduce indoor air pollution, enough ger in a district would need to be heated with electricity to significantly reduce the outdoor air pollution.

ОЦІНКА СТУПЕНЯ СКЛАДНОСТІ ВИЛУЧЕННЯ ВАЖКОВИДОБУВНИХ НАФТ НА ОСНОВІ ЇХНЬОЇ КЛАСИФІКАЦІЇ

The article discusses the results of the use of cluster analysis in assessing the degree of oil recovery complexity and its impact on the performance indicator. For this purpose, clustering was performed using a fuzzy cluster analysis algorithm. It should be noted that along with the deposits of heavy and highly viscous oils, a large share of hard-to-recover reserves is also confined to conditions with very low reservoir permeability values. Data on viscosity, oil density and oil permeability of in-situ conditions from various fields of Kazakhstan are collected. Using the results of this classification, a statistical analysis of indicators of various types of hard-torecover oils was performed. In the process of analysis, a generalized characteristic was determined for each class of oil, including viscosity, oil density and reservoir permeability. The generic characteristic is a linear transformation of the three characteristics. The results were subjected to statistical processing. At the same time, an attempt was made to establish and analyze the relationship between the degree of recovery complexity of hard-to-recover oils and oil recovery coefficient. In the course of the analysis, the average values of the oil recovery coefficient and the index of the degree of recovery complexity of hard-to-recover oil within each cluster were calculated and the relationship between them was plotted. The observed dependence, built on averaged points, is close to a power law, and, as one would expect, with an increase in the degree of oil recovery complexity, the oil recovery coefficient falls. The obtained estimates of the degree of oil recovery complexity allow us to rank different types of oils by their viscosity, density and reservoir permeability, which can be used to compare types of hard-to-recover oils by the value of the quality indicator. Methods to solve the problem of hard-to-remove high-viscosity and heavy oils should be aimed at reducing the viscosity of oil in the reservoir: injection of hot water / steam into the reservoir, the use of electric heaters, etc. Purpose. Assessment of the degree of oil recovery complexity and its impact on the efficiency of field development. The technique. The solution of the tasks set in the work was carried out on the method of mathematical statistics and the theory of fuzzy sets. In this case, the methods of processing the results, the correlation analysis, and the algorithm of fuzzy cluster analysis were used. Results. As a result of studies, 4 classes were obtained, each of which characterizes the degree of oil recovery complexity, a parameter was proposed for quantifying the degree of complexity, including oil density and viscosity, reservoir permeability, a relationship between this parameter and oil recovery coefficient was obtained. Scientific novelty. A classification of hard-to-recover reserves based on a fuzzy cluster analysis has been performed, and a parameter has been proposed for quantifying the degree of oil recovery complexity, a relationship has been obtained that allows judging the oil recovery by the degree of oil recovery complexity. Practical significance. The results obtained make it possible to classify hard-to-recover reserves and make decisions on the choice of methods for influencing the reservoir in various geological conditions.

Developing a predictive model for indoor black carbon for the Denver, CO metropolitan area

PDS 65: Exposure assessment: implications for epidemiology, Exhibition Hall (PDS), Ground floor, August 27, 2019, 1:30 PM - 3:00 PM Background: Though individuals spend ~90% of their time indoors, ambient air pollution data are frequently used in exposure assessment for epidemiologic studies. We sought to understand the relation between indoor and outdoor concentrations of black carbon (BC) and additional housing characteristics associated with indoor BC concentrations among cohort study participants in Denver, CO. Methods: Households from the Healthy Start cohort were selected for monitoring based on diversity in housing type and built environmental characteristics. For one week in spring and summer 2018, households were provided two low-cost air samplers, one for outdoor and one for indoor measurement. Participants completed questionnaires addressing housing specifics such as building type, flooring, and use of heating and cooling systems. BC was measured using transmissometry and weekly mean concentrations were log transformed prior to model fitting. A linear model was fit using all available predictors obtained from surveys as well as outdoor BC concentrations. Model selection was performed using stepwise backwards elimination; model fit was evaluated using AIC. Results: A total of 25 households participated in the study: 11 filters had BC measurements below LOD, and data were available for 39 filters. The average (SD) indoor and outdoor concentrations were 1.1 (0.8) and 1.2 (0.6) μg/m3, respectively. Outdoor BC concentrations were significant predictors of log(indoor BC) in a single-predictor model (β = 0.49, p = 0.02, R2=0.12). The final model included outdoor BC, single family home, tile flooring, and use of electric heater and had an adjusted R2 of 0.5. Conclusion: Outdoor BC and housing characteristics were able to account for ~50% of the variability in indoor BC concentrations measured in Denver, CO homes. In the absence of personal monitoring, household characteristics and time-activity patterns may be used in calibrating ambient air pollution concentrations for personal exposure estimation.

Prospects for the use of electric heaters with self-installing thermal contact based on nano-modified materials for aerospace engineering

The article presents the study of heat generation in the heating element, revealed the working temperature and the nature of the distribution of the temperature field. A method of experimental research has been developed that allows one to determine the thermophysical parameters and the distribution of the temperature field on the surface of the materials under study. It is established that the phase transition temperature is shifted by 2 ° C, and the measured thermal conductivity increased for modified heptadecane to a value of 0.3 W / m ° C. It was revealed that the use of a material with a phase transition provides the effect of a self-adjusting thermal contact. Improvement of thermal contact occurs within 20 seconds due to a phase transition in nano-modified heptadecane with its volume increasing by 2%.

Dehumidification in a Chinese Solar Greenhouse Using Dry Outdoor Air Heated by an Active Heat Storage-Release System

At nights during winter, Chinese solar greenhouses are heavily insulated with little ventilation and therefore suffer from high humidity. In this study we presented a dehumidification system that suits Chinese solar greenhouses. Dehumidification is achieved by introducing outside dry air into greenhouses after being heated. An active heat storage-release (AHS) system provided part of the heating energy. During daytime, the AHS system stores the surplus solar energy in water and releases this energy at night to the incoming outside dry air through a water-air heat exchanger. The outdoor dry air was drawn in by a ventilator (blower) and distributed evenly across the greenhouse through a plastic duct. Electric heaters served as auxiliary heating when the AHS system could not meet the heat demand. Experiments were conducted in two Chinese solar greenhouses in Beijing. One of the greenhouses was equipped with the dehumidification system and the other was not. This study showed that the relative humidity in the greenhouse with the dehumidification system was maintained below 85% while air temperature was not significantly lower than the greenhouse without the dehumidification system. The dehumidification system can remove vapor at the level of 15g m-2 h-1 at an air exchange rate of 1 h-1. The power requirement to drive the dehumidification system was 4.2 W m-2. For commercial application, the capacity of the AHS system needs to be increased to eliminate the use of electric heaters.

DESIGN, FABRICATION AND EXPERIMENTAL STUDY OF A FLAT PLATE COLLECTOR SIMULATOR

In this article, a flat plate collector simulator was designed and developed based on the use of electric heaters and a power control system. A computational algorithm aimed at determining the relationship between the incident solar energy on the collector absorber plate and the corresponding amount of power that must be supplied by the electrical resistance was developed. The variation in power is obtained by regulating the voltage fed through the assembly. With such regulation, simulating typical profiles of insolation over a day was possible. In the assessment of the average solar radiation data obtained by satellite imagery analysis (SWERA Project), the results showed that the thermal behavior of the simulator collector was close with a real behavior. Therefore, it can be used to determine the operating characteristics of auxiliary power systems as heat pumps, electrical systems or water heating systems. Different thermodynamic processes to determine the main losses of a collector evaluated the simulation parameters.

Development of thermoacoustic devices for power generation and refrigeration

This paper is intended as a technical overview of the research and development work initially undertaken at the University of Manchester and subsequently transferred to the University of Leicester as part of the EPSRC-funded SCORE project ( Stove for Cooking, Refrigeration and Electricity supply). The objectives of the work were twofold: Firstly, to develop an early demonstrator of a low-power electricity generator (to deliver approximately 10–20 W of electricity). This was to be based on the concept of using low-cost materials, working fluids and linear alternators suitable for deployment in rural areas of developing countries. The issues of concern here were the development of a suitable thermoacoustic engine topology and control measures; design of suitable heat exchanger configurations from initial use of electrical heaters to heat input through propane combustion; and characterisation of commercial loudspeakers to work as linear alternators and subsequent incorporation of selected models for engine prototyping purposes. These matters will be illustrated by a number of demonstrators and their testing in the laboratory environment. Secondly, to develop a demonstrator of a combustion driven thermoacoustic cooler for storage of vital medical supplies in remote and rural areas where there is no access to electricity grid. To this end, the paper will describe the design, construction and test results of an electrically driven demonstrator of a standing wave thermoacoustic engine coupled to a travelling wave thermoacoustic cooler. The final part of the paper will summarise the achievements to date and outline future work that has spun out from the original SCORE project. This will in particular include the current work on a scaled up version of electricity generator designed to deliver 100 W of electricity by using a two-stage engine configuration and the issues of integration of the thermoacoustic electricity generator and thermoacoustic cooler into one system.

Response of four stored products insects to a structural heat treatment in a flour mill

Heat treatment is an ecologically sustainable technique that can be used as an alternative to chemical pesticides. The objective of this trial was the evaluation of efficacy of a commercial structural heat treatment, performed by means of electric heaters in a flour mill. Maximum temperatures, time above 50 °C and to reach 50 °C were different for each floor of the treated mill. Susceptibility to elevated temperature of different life stages of Tribolium confusum, Gnatocerus cornutus, Sitophilus oryzae, and Rhyzopertha dominica are reported. The mortality at 12, 24 and 36 h after the beginning of the heat exposure was evaluated. Eggs of T. confusum were the most sensitive stage to heat treatment. For total effectiveness of the treatment, a time between 24 and 36 h was necessary. The use of electric heaters could represent a viable alternative to other methods used for pest control in the milling sector.

Determinants of residential electricity consumption: Using smart meter data to examine the effect of climate, building characteristics, appliance stock, and occupants' behavior

We propose a method to examine structural and behavioral determinants of residential electricity consumption, by developing separate models for daily maximum (peak) and minimum (idle) consumption. We apply our method on a data set of 1628 households' electricity consumption. The results show that weather, location and floor area are among the most important determinants of residential electricity consumption. In addition to these variables, number of refrigerators and entertainment devices (e.g., VCRs) are among the most important determinants of daily minimum consumption, while number of occupants and high-consumption appliances such as electric water heaters are the most significant determinants of daily maximum consumption. Installing double-pane windows and energy-efficient lights helped to reduce consumption, as did the energy-conscious use of electric heater. Acknowledging climate change as a motivation to save energy showed correlation with lower electricity consumption. Households with individuals over 55 or between 19 and 35 years old recorded lower electricity consumption, while pet owners showed higher consumption. Contrary to some previous studies, we observed no significant correlation between electricity consumption and income level, home ownership, or building age. Some otherwise energy-efficient features such as energy-efficient appliances, programmable thermostats, and insulation were correlated with slight increase in electricity consumption.

Efficiency of electrically heating the lining of steel-pouring ladles

A mathematical model has been developed to describe the cooling of steel in a pouring ladle as the steel is held in the ladle prior to its treatment on a ladle-furnace unit. The adequacy of the model is demonstrated, and calculations of the cooling of steel in a ladle are performed. It is shown that preheating ladle linings to 1400 °C with the use of electric heaters is a cost-effective measure.

Development of an energetic diagnosis method for the buildings: example of the Perugia University

The paper suggests a methodology for energetic buildings diagnosis for the Perugia University [Energy Buildings 1436 (2002) 1; B. Puttinger, Guideline for implementing energy audits in public buildings, Landes Energie Verein; R. Recalcati, G. Dall’O’, Procedure for buildings energetic certification, Punto Energia, Brescia (1998)]. All of the university buildings have been put into six poles according to their geographical location. First of all, the entire area was subdivided into blocks according to didactics, office, and research areas. On the basis of this division, the utilization coefficient of the specific areas was determined for each pole. The paper suggests a method for pole electric consumption dividing into the three terms related to didactics, office, and laboratory block by the definition of the three “area indexes” C did.A, C off.A, and C lab.A which represent the specific consumption per square meter of dedicated area. Their values, and in particular C lab.A value, vary according to the nature of the activities carried out in each pole. Starting from “area indexes”, the three “user indexes” ( C stu.U, C per.U, and C res.U) were then defined considering students, personnell, and researcher, separately. Area and user indexes’s yearly evaluation, dependent on the users number per typology and the blocks area, allows to identify the increasing or decreasing characteristic of the intensity of the activities carried out in each pole, to determine if consumptions depend mainly on class activities being carried out or on the use of electric heater and air conditioning systems. Finally, thermal consumptions were analyzed by evaluating the yearly energy amount and the specific consumption of each pole according to age and state of the buildings.

Low-Temperature Drying Using a Versatile Heat Pump Dehumidifier

A drying system incorporating a commercial 2.3 kW heat pump dehumidifier was designed and constructed. The HPD was equipped with an external water-cooled condenser that rejected excess heat out of the system. The design of the system allowed for conducting drying with recirculation of air as well as use of electrical heaters. In an open mode, the drying could be carried out simultaneously with room dehumidification and water heating in the secondary condenser. Drying experiments were conducted with apple and comparisons were made between HPD assisted drying (partial and complete) and hot air drying (at 45 and 65°C). The HPD dried fruit exhibited better rehydration properties than the hot air dried samples. Water activity of the HPD dried samples was noticeably lower than that of the hot air dried samples at the same water content, indicating that the residual moisture was probably held under higher tension in the former. In terms of energy consumption, the process of HPD assisted drying is more expensive as much of the energy input is rejected at the secondary condenser as excess heat.

Test and calibration processes for microcalorimeters, with special reference to heat conduction instruments used with aqueous systems

Calorimeters are normally calibrated by use of electrical heaters, but the calibration values derived may not always be representive for the chemical or biological proces investigated. It is therefore important to have available chemical test processes by whic the electrical calibration values can be controlled. In some cases, electrical calibration should be replaced by chemical calibrations. With particular reference to needs in work with thermopile heat conduction microcalorimeters, a number of test and calibration processes are presented. Some calibration problems for various types of reaction vessel are discussed.

The Culture of Penaeus Japonicus in Japan1

ABSTRACTThe Japanese are recognized as having played a major role in the development of aquaculture. They have developed techniques for culturing several marine and freshwater species. Their methods for commercially culturing the shrimp Penaeus japonicus (“Kuruma‐Ebi”) are of particular importance because of the growing interest by the United States, in shrimp culture, stimulated by the present consumer demand for shrimp.Spawning stock of P. japonicus may be acquired by two methods. First, they may be collected at the fishery wharves where they are landed alive by Japanese fishermen. Second, techniques have been developed to mature sexually, mate, and spawn these shrimp in captivity. The latter method, however, has not been incorporated into the commercial operation because the expense and time required make the process uneconomical.Once collected, gravid females are spawned in rearing tanks of various sizes. The most popular tank in use is made of cement which has a capacity of about 200 m3. Its dimensions are 10 m × 10 m × 2 m. The number of spawners required per tank is determined primarily by the season of the year. In early spring only about 5% of the 100 to 200 gravid females placed in each tank will successfully spawn whereas in autumn about 50% of the 25 to 50 used will spawn successfully. Despite this seasonal variation, about 50% of the eggs spawned will hatch.During larval culture, water temperature is maintained near 28 C by circulating live steam through pipes submerged in the rearing tank. Experience has demonstrated that the use of steam is more economical and safer than the use of electric heaters. As soon as the eggs hatch, the water is fertilized so that a dense growth of phytoplankton will be present when the nauplii metamorphose to the protozoeal (zoeal) stage. Unfortunately, adequate blooms do not always occur, or cannot be maintained. In such instances, soybean cake (SBC) is added. Preliminary results with SBC indicate that it serves as a fertilizer for phytoplankton and as a food for larval shrimp. A postlarval crop of about 1 million (20 to 25 days old, 15 to 20 mm long, and weighing 18 to 20 mg) can be expected from one 200 m3 tank.Postlarval shrimp are stocked in ponds at a density of 12 to 15 per m2 in the winter and 20 to 25 per m2 in the early summer. Market sized shrimp (20 to 25 g) can be harvested from ponds in 5 to 6 months with approximately 50% survival from the date of stocking. During the pond culturing operation on a typical commercial prawn farm, the Japanese feed primarily natural foods such as bivalve meat, euphausids, mysids, and scrap fish. Because of the supply and demand, however, the costs of these foods are increasing. In 1969, an estimated 200 metric tons of shrimp were produced in about 100 ha of ponds. At the Tokyo Center Fish Market live shrimp sell for between $7 and $30 per kg although the average price is $10 to $11 per kg. Production costs are about $7 per kg.Two major problems confront the Japanese aquaculturists. First, diseases occurring during the culture process cannot be controlled, occasionally resulting in total mortality of the shrimp. Second, an acute shortage of labor exists in the field of fisheries and aquaculture. Although more young people are graduating from college than ever before, they are entering the fields of manufacturing. Consequently, the labor force required for fisheries and aquaculture is dependent upon the older age groups of men and women.

A calorimeter for determining specific heats of liquids

This paper presents a calorimeter that circumvents difficulties associated with the use of electrical heaters by relying on a chemical reaction as the heat source.