Evaluation of the Effectiveness of Heating Systems Applied in City Buses

2013 ◽  
Vol 391 ◽  
pp. 185-190
Author(s):  
Maciej Bajerlein ◽  
Jerzy Merkisz ◽  
Pawel Daszkiewicz

The paper presents energy saving opportunities in by analyzing two types of auxiliary heating systems. Objects of study were two heaters differing in power requirements and fuel consumption (used for water heating system). The heaters were installed in city buses of the same layout and identical convector heaters fitted for optimum temperature of the vehicle interior and the engine. Through the use of a portable device SEMTECH DS (PEMS) the exhaust emissions of CO, HC, NOx, CO2 were measured. The testing of the heaters for emissions and the testing of the temperature distribution inside the vehicle were performed in stationary conditions, determining the impact of the heating on the energy consumption of the heaters and temperature comfort inside the vehicle. The measurements were performed for each vehicle at the same ambient temperature, which was about 10°C [2, 3, 5]. So that the temperature increase inside the vehicle could be compared the tested vehicles were conditioned before the measurement. The obtained temperature distributions were determined along with a relative increase in the temperature in the vehicle interiors heated by the tested objects. The temperature measurement was performed with the use of six thermocouples utilizing a signal converter - IOTECH PERSONAL DAQ 3000.

Author(s):  
A. I. Nizhegorodov

The design of the suspended nonlinear heating system of modular-trigger and platform furnaces for firing vermiculite and other bulk materials is considered. Previously, the design of linear heating systems did not provide homogeneous heating of thermographed materials, the material in the clutch zones suffered sufficient thermal energy. In addition, overheating of the central zone increased the frequency of the impact of the heaters themselves, which affected the reliability of the furnace. The use of a nonlinear heating system has changed this distribution to the opposite. The power of the intuboxic heater exceeded the power of the central 1,2‒1,36 times depending on the ratio of the diameters of thin and thick (diameter of 4 mm) of the heaters. At the same time, not only their electrical power increased, but the heat radiation streams, falling onto the surface of the supply, which led to an increase in the temperature of the material being processed. The obtained values of the temperature of the vermiculite grains in the fitted zones of the firing module exceed the temperature of the vermiculite in the central zone by 26 %, while it is sufficient for high-quality material intimidation. Due to the use of nonlinear heating system, temperatures were redistributed on heated surfaces in favor of relatively cold previously intuition zones: the heat picture has changed to the opposite, that is, the cold cloth zones have become relatively hot. Ill. 8. Ref. 14.


Author(s):  
Florin-Emilian Turcanu ◽  
Marina Verdes ◽  
Vasilica Ciocan ◽  
Catalin George Popovici ◽  
Sebastian Valeriu Hudisteanu

The paper describes the behaviour of a heating system with radiators in a cult building. There has commonly used in many churches with many shortcomings. The temperature distribution in the analysed space is simulated in 2D. The simulation is based on an example, the Cathedral of the Assumption of the Virgin Mary in Jassy. The heating system with radiators simulated with the FLUENT program, the results being edifying for the factual state of the building. An important aspect is the impact of these heating systems on the works of art, the church being the 18th — century edifice. Current environmental issues lead to the continuous development of technologies used to reduce primary energy consumption. Churches are an invaluable wealth, sheltering heritage elements preserved in museums and historic buildings. Unheated churches have been used for centuries. Then, after installing one or more different heating systems, signs of rapid degradation appeared.


2015 ◽  
Vol 81 (5) ◽  
Author(s):  
S. Heuraux ◽  
F. da Silva ◽  
T. Ribeiro ◽  
B. Despres ◽  
M. Campos Pinto ◽  
...  

Firstly, a brief overview will be given on different models that are able to describe the behaviour of wave propagation as a function of specific frequency ranges. Each range corresponds to different heating systems, namely, 20–100 MHz for the ion cyclotron resonant heating, 2–20 GHz for lower-hybrid heating or current drive, and 100–250 GHz for electron cyclotron resonant heating or current drive systems. The specification of every system will be explained in detail, including the typical set of equations and the assumptions needed to describe the properties of these heating or current drive systems, as well as their specific domains of validity. In these descriptions, special attention will be paid to the boundary conditions. A review of specific physical problems associated with the wave heating systems will also be provided. The review will detail the role of simulation in answering questions that arise from experiments on magnetized plasma devices devoted to fusion. A few examples that will be covered are the impact of edge turbulence on wave propagation and its consequences on heating system performance, the effects of fast particles and ponderomotive effects, among others. A study that is more focused on radio-frequency sheath effects will also be discussed. It shows that such simulations require very sophisticated tools to gain a partial understanding of the observations undertaken in dedicated experiments. To conclude this review, an overview will be given about the requirements and progress necessary to obtain relevant predictive simulation tools able to describe the wave heating systems used in fusion devices.


2020 ◽  
Vol 11 (2) ◽  
pp. 409-428
Author(s):  
Inmaculada García-Maroto ◽  
Francisco Muñoz-Leiva ◽  
Elena Higueras-Castillo ◽  
Francisco Liébana-Cabanillas

Purpose Understanding the antecedents of biomass heating adoption by domestic users is important for both public authorities and businesses because of the impact of this technology on energy consumption. The purpose of this study offers an overview of the predictors of biomass adoption based on the most relevant theories, gleaned from pro-environmental decision-making research. Design/methodology/approach The proposed model was tested using the partial least squares technique. The study was conducted with a sample of 528 owners of detached houses who did not use biomass technology. Findings The results showed that intention to adopt this type of heating system is determined by individual values, environmental concerns, attitudes, perceived control, personal and social norms, perceptions of the technology’s attributes, of the benefits of biomass and access to economic aid. Practical implications Companies in the biomass heating sector (manufacturers, installers, biomass producers and distributors) and public bodies should take a proactive approach toward the economic and environmental situations they currently face. Social implications Economic aid or subsidies should be made available to influence the adoption intention of potential owners; and the availability of the aid and the requirements that must be met to access, it should be publicized through advertisement campaigns. Originality/value This study includes comprehensive academic and managerial implications crucial for the introduction of domestic biomass heating systems.


2014 ◽  
Vol 14 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Alona Bolonina ◽  
Genadijs Bolonins ◽  
Dagnija Blumberga

Abstract District heating systems are widely used to supply heat to different groups of heat consumers. The district heating system offers great opportunities for combined heat and power production. In this paper decreasing district heating supply temperature is analysed in the context of combined heat and power plant operation. A mathematical model of a CHP plant is developed using both empirical and theoretical equations. The model is used for analysis of modified CHP plant operation modes with reduced district heating supply temperature. Conclusions on the benefits of new operation modes are introduced.


2019 ◽  
Vol 2 (1) ◽  
pp. 29-39 ◽  
Author(s):  
S. G. Konesev ◽  
P. A. Khlyupin

Introduction: the systems of thermal effects on thermo-dependent, viscous and highly viscous liquids under conditions of the Arctic and the Extreme North are considered. Low efficiency and danger of heating systems based on burned hydrocarbons, heated liquids and steam are shown. Electrothermal heating systems used to maintain thermo-dependent fluids in a fluid state are considered. The evaluation of the effectiveness of the application of the most common electrothermal system — heating cables (tapes). The most effective electrothermal system based on induction technologies has been determined. Materials and methods: considered methods of thermal exposure to maintain the fluid properties of thermo-dependent fluids at low extreme temperatures. Results: presents an induction heating system and options for its implementation in the Extreme North and the Arctic. Conclusions: induction heating system to minimize loss of product quality, improve the system performance under changing process conditions, eliminate fire product, to reduce the influence of the human factor.


2021 ◽  
Vol 11 (14) ◽  
pp. 6254
Author(s):  
Elena G. Dascalaki ◽  
Constantinos A. Balaras

In an effort to reduce the operational cost of their dwellings, occupants may even have to sacrifice their indoor thermal comfort conditions. Following the economic recession in Greece over recent years, homeowners have been forced to adapt their practices by shortening heating hours, lowering the indoor thermostat settings, isolating spaces that are not heated or even turning off their central heating system and using alternative local heating systems. This paper presents the results from over 100 occupant surveys using questionnaires and walk-through energy audits in Hellenic households that documented how occupants operated the heating systems in their dwellings and the resulting indoor thermal comfort conditions and actual energy use. The results indicate that the perceived winter thermal comfort conditions were satisfactory in only half of the dwellings, since the actual operating space heating periods averaged only 5 h (compared with the assumed 18 h in standard conditions), while less than half heated their entire dwellings and only a fifth maintained an indoor setpoint temperature of 20 °C, corresponding to standard comfort conditions. Mainstream energy conservation measures include system maintenance, switching to more efficient systems, reducing heat losses and installing controls. This information is then used to derive empirical adaptation factors for bridging the gap between the calculated and actual energy use, making more realistic estimates of the expected energy savings following building renovations, setting prudent targets for energy efficiency and developing effective plans toward a decarbonized building stock.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3218
Author(s):  
Pedro Durán ◽  
Herena Torio ◽  
Patrik Schönfeldt ◽  
Peter Klement ◽  
Benedikt Hanke ◽  
...  

There are 1454 district heating systems in Germany. Most of them are fossil based and with high temperature levels, which is neither efficient nor sustainable and needs to be changed for reaching the 2050 climate goals. In this paper, we present a case study for transforming a high to low temperature district heating system which is more suitable for renewable energy supply. With the Carnot Toolbox, a dynamic model of a potential district heating system is simulated and then transformed to a low temperature supply. A sensitivity analysis is carried out to see the system performance in case space constrains restrict the transformation. Finally, an economic comparison is performed. Results show that it is technically possible to perform the transformation until a very low temperature system. The use of decentralized renewable sources, decentralized heat storage tanks and the placement of a heat pump on each building are the key points to achieve the transformation. Regarding the sensitivity analysis, the transformation is worth doing until the seasonal storage and solar collector field sizes are reduced to 60% and 80% of their values in the reference case, respectively. The economic analysis shows, however, that it is hard for highly efficient low temperature renewable based heat networks to compete with district heating systems based on a centralized fossile CHP solution. Thus, though the presented transformation is technically possible, there is a strong need to change existing economic schemes and policies for fostering a stronger promotion of renewable energy policies in the heat sector.


2021 ◽  
Vol 3 (1) ◽  
pp. e000084
Author(s):  
Naveed Akhtar ◽  
Salman Al Jerdi ◽  
Ziyad Mahfoud ◽  
Yahia Imam ◽  
Saadat Kamran ◽  
...  

IntroductionThe COVID-19 pandemic has resulted in a dramatic unexplained decline in hospital admissions due to acute coronary syndromes and stroke. Several theories have emerged aiming to explain this decline, mostly revolving around the fear of contracting the disease and thus avoiding hospital visits.AimsIn this study, we aim to examine the impact of the COVID-19 pandemic on stroke admissions to a tertiary care centre in Qatar.MethodsThe Hamad General Hospital stroke database was interrogated for stroke admissions between September 2019 and May 2020. The number of stroke admissions, stroke subtypes and short-term outcomes was compared between the ‘pre-COVID-19’ period (September 2019 to February 2020) and the COVID-19 pandemic period (March to May 2020).ResultsWe observed a significant decline in monthly admissions in March (157), April (128) and May (135) compared with the pre-COVID-19 6-month average (229) (p=0.024). The reduction in admissions was most evident in functional stroke mimics. The average admissions decreased from 87 to 34 per month (p=0.0001). Although there were no significant differences in admissions due to ischaemic stroke (IS), intracranial haemorrhage or transient ischaemic attacks between the two periods, we noted a relative decrease in IS due to small vessel disease and an increase in those due to large vessel atherosclerosis in March to May 2020.ConclusionsThe decline in overall stroke admissions during the COVID-19 pandemic is most likely related to concerns of contracting the infection, evidenced mainly by a decline in admissions of stroke mimics. However, a relative increase in large vessel occlusions raises suspicion of pathophysiological effects of the virus, and requires further investigation.


2021 ◽  
Vol 11 (12) ◽  
pp. 5511
Author(s):  
Szymon Grzesiak ◽  
Andrzej Adamkiewicz

The paper presents the results of the numerical research of the steam jet injector applications for the regenerative feed water heating systems of marine steam turbine propulsion plants. The analysis shows that the use of a single injector for a single heat exchanger results in a relative increase in the thermal efficiency of the plant by 0.6–0.9%. The analysis also indicates the legitimacy of the usage of multistage feed water heating systems, which would enable the operating parameters optimization of the injectors. The obtained steam pressure up to the value of 1.8 barA allows for the heating of the feed water up to 110 °C. For higher degrees of feed water heating in the heat exchangers, it is necessary to supply heating steam of higher pressure. Therefore, the usage of two-stage steam jet injector units was considered advisable for the analyses.


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