Showing papers on "Heating system published in 2009"

Design of biomass district heating systems

Abstract: The biomass exploitation takes advantage of the agricultural, forest, and manure residues and in extent, urban and industrial wastes, which under controlled burning conditions, can generate heat and electricity, with limited environmental impacts. Biomass can – significantly – contribute in the energy supplying system, if the engineers will adopt the necessary design changes to the traditional systems and become more familiar with the design details of the biomass heating systems. The aim of this paper is to present a methodology of the design of biomass district heating systems taking into consideration the optimum design of building structure and urban settlement around the plant. The essential energy parameters are presented for the size calculations of a biomass burning-district heating system, as well as for the environmental (i.e. Greenhouse Gas Emissions) and economic evaluation (i.e. selectivity and viability of the relevant investment). Emphasis has been placed upon the technical parameters of the biomass system, the economic details of the boiler, the heating distribution network, the heat exchanger and the Greenhouse Gas Emissions.

A feasibility study of self-heating concrete utilizing carbon nanofiber heating elements

Abstract: This paper presents the development of an electric, self-heating concrete system that uses embedded carbon nanofiber paper as electric resistance heating elements. The proposed system utilizes the conductive properties of carbon fiber materials to heat a surface overlay of concrete with various admixtures to improve the concrete's thermal conductivity. The development and laboratory scale testing of the system were conducted for the various compositions of concrete containing, separately, carbon fiber, fly ash, and steel shavings as admixtures. The heating performances of these concrete mixtures with the carbon fiber heating element were experimentally obtained in a sub-freezing ambient environment in order to explore the use of such a system for deicing of concrete roadways. Analysis of electric power consumption, heating rate, and obtainable concrete surface temperatures under typical power loads was performed to evaluate the viability of a large scale implementation of the proposed heating system for roadway deicing applications. A cost analysis is presented to provide a comparison with traditional deicing methods, such as salting, and other integrated concrete heating systems.

Life cycle assessment of wood-based heating in Norway

Abstract: In this study, we evaluate the environmental effects of wood-based household heating. Wood is a significant source of household heating in Norway, and a comparative life cycle assessment of a wood-based heating system using an old and a modern stove was conducted to estimate the total life cycle benefits associated with the change from old to new combustion technology. The study uses a new approach to complete the inventory. Input–output data are used in combination with the Leontief price model to estimate inputs of products and services from the background economy to the birch wood supply chain. When comparing new and old stove technology, the results show that the new technology contributes to a significantly improved performance (28–80%) for all types of environmental impact studied. As there is a large share of old wood stoves still in use, replacing the old stoves with new ones can lead to substantial reductions in environmental impacts, especially impacts affecting human health. The use phase, i.e., wood combustion, is responsible for over 60% of the impact within all categories. Both the old and new stove provide heating with emissions of greenhouse gases ranging from one third (new stove, ∼80 g CO2-eq/kWh) to half (old stove, ∼110 g CO2-eq/kWh) of the impacts compared to electricity use from the Nordic electricity mix (∼210 g CO2-eq/kWh) to heat the house. Combustion of the wood is found to be most important for all types of impacts, even for global warming, where the CO2 emissions from combustion are treated as “climate neutral.” Products of incomplete combustion are the reason for this, as well as the high contribution to other impact categories. Emission factors for these substances are subject to high uncertainty. Although the combustion phase is the most important stage in the life cycle, transportation distances can play an important role. To render wood as environmentally benign as possible, one should thus seek to shorten the distances from producer to consumer. There is a significant difference in the life cycle performance of a wood stove using modern technology versus older technologies within all impact categories. In addition, there is a preference to use locally produced firewood over wood transported over long distances. A strong emphasis on phasing out old woodstoves should be maintained and is well justified.

Energy management improvement for a heating system with reduced setpoint temperature during no occupancy based upon historical sampling of room thermal response with highest power heat applied

Abstract: A thermostat apparatus for controlling a heat pump with supplemental resistive heating as typically contained in a Packaged Terminal Air Conditioning (PTAC) unit is disclosed which provides improvements in energy management by reducing energy usage as much as possible within user guidelines when the conditioned space served by the PTAC is not occupied. A reduced setpoint temperature determination is based upon measurements of thermal response within the conditioned space to application of supplemental or resistive heat, and utilizes supplemental or resistive heat in achieving a quick recovery when people enter the conditioned space, thus enabling a more reduced setpoint temperature when the space is not occupied.

A fuzzy logic based efficient energy saving approach for domestic heating systems

Abstract: This paper focuses on the designing of an energy saving method for a domestic heating system based on electrical heaters. A multi-agent system architecture with two fuzzy rule based systems has been used: a fuzzy model, to estimate the energy requirements and a fuzzy controller, to distribute the energy to all of the installed heaters. The aim is to reduce the energy spent for heating the house while maintaining the predefined comfort level. The proposal has proved valid in realistic simulations, although some revisions must be be carried out prior to integrating it into a microcontroller hardware. The real prototype must also be validated in real situations. This system is to be included in the local company's product catalogue.

A Natural-Gas-Fired Thermoelectric Power Generation System

Abstract: This paper presents a combustion-driven thermoelectric power generation system that uses PbSnTe-based thermoelectric modules. The modules were integrated into a gas-fired furnace with a special burner design. The thermoelectric integrated system could be applied for self-powered appliances or micro-cogeneration. A mathematical model for the integrated energy system was established that considered irreversibilities in the thermal-to-electric energy conversion process. The electric power output and electrical efficiency of the system were simulated using the established model. A prototype system was developed and its performance was investigated at various operating conditions. Applicability of thermoelectric devices to self-powered heating systems was demonstrated. The thermoelectric integrated combustion system could provide the consumer with heating system reliability and a reduction in electric power consumption. The integrated system could also offer other advantages including simplicity, low noise, clean operation, and low maintenance.

A Modelica-based Model Library for Building Energy and Control Systems

Abstract: This paper describes an open-source library with component models for building energy and control systems that is based on Modelica, an equation-based objectoriented language that is well positioned to become the standard for modeling of dynamic systems in various industrial sectors. The library is currently developed to support computational science and engineering for innovative building energy and control systems. Early applications will include controls design and analysis, rapid prototyping to support innovation of new building systems and the use of models during operation for controls, fault detection and diagnostics. This paper discusses the motivation for selecting an equation-based object-oriented language. It presents the architecture of the library and explains how base models can be used to rapidly implement new models. To demonstrate the capability of analyzing novel energy and control systems, the paper closes with an example where we compare the dynamic performance of a conventional hydronic heating system with thermostatic radiator valves to an innovative heating system. In the new system, instead of a centralized circulation pump, each of the 18 radiators has a pump whose speed is controlled using a room temperature feedback loop, and the temperature of the boiler is controlled based on the speed of the radiator pump. All flows are computed by solving for the pressure distribution in the piping network, and the controls include continuous and discrete time controls.

Catalyzed hot gas heating system for concentrated solar power generation systems

Abstract: A solar power generation system includes a fluid housing, a solar collector, and a heating system. The fluid housing contains a heat transfer medium. The solar collector concentrates solar energy onto the heat transfer medium. The heating system includes at least one gas tank containing a gas and fluidically connected to a first catalyst. The first catalyst is configured to catalyze gas from the gas tank to create hot gas. The heating system also includes a first hot gas pipe fluidically connected to the first catalyst and positioned with respect to the fluid housing such that hot gas flowing through the first hot gas pipe comes into thermal contact with the heat transfer medium within the fluid housing.

Radiant heating using heater coatings

Abstract: A radiant heating system comprises a thermally sprayed resistive heating layer bonded to an underlayment building material substrate. The substrate can comprise a sub-flooring material and the heating system can comprise a radiant floor heating system. The resistive heating layer can be thermally sprayed directly onto a sub-floor or similar underlayment material, including a cementitious backing material or a sound reduction board. A finished floor surface, such as a tile, wood or laminate surface, can be provided over the substrate and thermally sprayed heater to provide a radiant floor heater. In other embodiments, a radiant heating system includes a thermally sprayed heater bonded to a flooring overlay, such as a laminate board, to a heater insert, such as a flexible polymer film or a mica-based material, or to a concrete substrate. Methods of fabricating radiant heating systems include thermally-spraying a resistive material on a sub-floor or flooring overlay.

Heating system having at least one electrothermal heating layer, a structural component having such a heating layer, a heating method and a method for producing a semi-finished component or a component having a heating device

Abstract: The invention relates to a heating system (1) comprising an energy supply device (5), wherein the heating system (1) comprises: a base heating device having an insulating layer, having an electrothermal base heating layer (10) arranged thereon and an electrical connection device (10a, 10b) via which the energy supply device (5) is connected to the base heating layer (10), an auxiliary heating device having an insulating layer, having an electrothermal auxiliary heating layer (11) arranged thereon and an electrical connection device (11a, 11b) via which the energy supply device (5) is connected to the auxiliary heating layer (11), wherein the energy supply device (5) is connected to the heating layers (10; 11) via the connection devices (10a, 10b; 11a, 11b) and the auxiliary heating layer (11) is supplied with current in the activation phase at least in a partial temporal period so that the base heating layer (10) continually produces heat and the auxiliary heating layer (11) produces heat during the partial temporal period. The invention further relates to a structural component having a device for heating a surface of the structural component and to an arrangement of a structural component and a heating system.

Circuit heating plant model with internal delays

Abstract: The aim of this paper is to utilize an unordinary anisochronic modelling principle on a circuit thermal laboratory plant. The class of anisochronic models is characterized by the existence of state (internal) delays, both distributed or lumped ones. The modelled laboratory appliance was designed at Tomas Bata University in Zlin, Czech Republic, as a thermal heating circuit small scale model with dynamic properties similar to that of a real heating system (e.g. a cooling circuit in cars). The motivation for the modelling of this plant was double. First, the dynamics of the plant exhibits unconventional step responses which cannot be explained by a standard analytic means. Second, the authors of this contribution intend to use the obtained anisochronic mathematical description of the plant with the view of the verification of algebraic control algorithms in the RMS ring designed for delayed systems earlier.