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ČIŽMAN, J., STANIČIĆ, D., ČESEN, M., ROŽMAN, M., GERMIČ, L., KOKALJ, F.
Concept of Conducting a Spatial Analysis of Heat Consumptionand Supply in the City Of Maribor
KOMUNALNA ENERGETIKA / POWER ENGINERING, 9
Sustainable heating and cooling solutions are based on modern technologies and increasing integration of various sectors of energy consumption and energy production – buildings, industry, electricity generation, and transport. District heating and cooling systems enable integration of various sectors, thus allowing for efficient management of all available energy sources and sinks. When planning energy management in a local community, such solutions require a systemic approach based on thorough spatial analysis of the current state and future development. The paper introduces the concept of conducting a spatial analysis of heat consumption and supply by using geographic information system tools of the City of Maribor.
VORŠIČ, Ž., KUMPERŠČAK, V., PIHLER, J.
HEATING OF CONDUCTORS IN STEADY STATE
KOMUNALNA ENERGETIKA / POWER ENGINERING, 15
Several factors influence the choice of conductor cross-section when planning distribution and transmission networks, such as voltage drop, loss of power, stability, protection and others. Important factor is also conductor temperature rise above surrounding temperature. To determine it one must know maximum continuous current which determines maximum allowed conductor temperature. The temperature of the conductor affects the conductor sag between the pillars and determines the change in tensile strength due to heating. Conductor temperature is authoritative guide for selecting conductors for short connecting lines in extreme condition.
Three temperatures are relevant: Joule heating depends on average conductor temperature and convection and radiation depends on conductors’ surface temperature. Change (decrease) of tensile strength is in first approximation dependent on temperature of strands in the middle of conductor.
Article shows how individual influencing factors act on conductor by heating or cooling it in steady operation.
VORŠIČ, Ž., PIHLER, J., MARUŠA, R.
HEATING OF CONDUCTORS IN STEADY STATE II
KOMUNALNA ENERGETIKA / POWER ENGINERING, 26
Factors such as voltage drop, power losses, stability, protection etc are important when selecting conductors cross-section in distribution and transmission networks. Important factor is also the rise of the temperature over the surrounding temperature: it is necessary to know the maximum continuous conductor current since it determines the maximum permissible temperature of conductor. The temperature of the conductor affects the conductor sag between the columns and determines the change in tensile strength due to warming. For short connection lines conductor temperature in emergency conditions is relevant for selection of the conductors cross-section.
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