Final Program EXPRES 2012 - Conferences

QQ⎛ Λt⎞=⎜⎟⎝ Λ ⎠Nt Nwhere n = is the exponent related to the heating panel.The figure below shows heating outputs attainable byoperation at lower temperature levels at an internaltemperature of t i = 20°C.nHere we mean various variants of heating in heat pumpsystems based, e.g., on escaping thermal water alreadyused, escaping water of swimming pools regarded assewage, escaping water of baths, etc. ...Usefulness of heat pumps is illustrated by anelectricity-driven heat pump connected to the return sideof a convection heating, producing heat of 50 °Ctemperature for .floor heating and wall heating.Cascade connection is also a usual solution with two(or more) heat exchangers for heating systems working atcontinuously diminishing temperature levels.This is of utmost importance when the temperature ofthermal water on the heat source side and temperaturecoming to the surface is lower than usual in heating.Therefore it is important to enable usage of thermalwaters for heating buildings within a wider and widertemperature range.In the case of lower thermal water temperature levels,the same system can be operated with a heat pump andpeak boiler plant. At the same time, this peak boiler plantserves as a 100% reserve in the heating season.III. DISTRICT HEAT SUPPLY SYSTEMSThe modern district heat systems with re-injection havetwo major types:a.) The thermal water heat exchanger transfers heat tothe whole district heat network centrally, i.e. soft watercirculates in the network.b.) Thermal water flows in the network to theconsumers, and heat transfer occurs through heatexchangers in the receiving thermal centres. This lattertype is applicable where thermal water is used also watertechnologically(e.g. in thermal baths). Its drawback isgas escape and salting in the whole network which shouldbe treated.15