12th International Symposium on District Heating and Cooling

The <strong>12th</strong> <strong>International</strong> <strong>Symposium</strong> on District Heating and Cooling,September 5 th to September 7 th , 2010, Tallinn, EstoniaEFFICIENCY OF DISTRICT HEATING WATER PUMPING IN FINLANDAntti Hakulinen 1 , Jarkko Lampinen 1 and Janne Lavanti 11 Pöyry Finland OyABSTRACTThe objective of this study was to determine thesavings potential in district heating pumping in Finland.A measurement method was also developed to quicklyestimate the efficiency of district heating pumping.The work was based on the data gathered from districtheating statistics. The work is divided into two parts.The district heating statistics reveal a number of districtheating networks whose consumption of energyneeded for pumping is exceptionally high. Thesecompanies should clarify the reasons for that.In addition, companies with an exceptionally lowconsumption of pumping energy should check theirmeasurements and data gathering routines.On average the electricity needed for district heatingpumping should not be over 0.5 per cent of the totalenergy supply (=sold+losses). If the density(supply/length of the network) of the district heatingnetwork is less than 3 GWh/km, the energy needed forpumping may rise. In any case the proportionalpumping energy should be lower than 1 per cent oftotal energy supply.90 000 €80 000 €70 000 €60 000 €50 000 €40 000 €30 000 €20 000 €10 000 €The investment costs of a pump0 €0 100 200 300 400 500pow er kWFig. 1. The investment costs of a pump.1.2 Total costs of pumpingTotalPumpFrequency converterTotal costs of pumping include capital, maintenanceand energy used in pumping. The pump lifetime costsare mainly energy costs as we can see from figure 2 onthe next page. The lifetime costs are calculated withthe following assumptions: energy price € 60/MW/h,operating lifetime 15 years, utilization period ofmaximum load 5000 h/a, interest rate 5 per cent andthe O&M 1.2 per cent of the investment.Pump I, pow er: 16 kWMotorThe Finnish potential for saving in district heatingpumping is estimated to be 20 per cent of the currentpumping energy i.e. 30 GWh/a. This is equivalent to ayearly saving of approximately € 2 million.PART 1.INTRODUCTIONIn the Finnish district heating systems no typicalpumping arrangements have been used at heatproduction plants or at booster pump stations. Theways of dimensioning and connecting pumps havevaried a lot. This has led to incorrect dimensioning andconnections of pumps, which in turn has caused higherinvestment costs and greater pumping energy usagethan expected, operational problems and in the worstcase many interruptions in the use of the network. TheFinnish district heating system is based on the variableflow operation (consumer driven scheme)1. COSTS14 %2 %84 %Pump II, pow er: 131 kW7 % 1 %92 %Pump III, pow er: 283 kW5 %1 %CapitalO&MEnergyCapitalO&MEnergyCapitalO&MEnergy1.1 The investment costs of a pump (includingmotor and controls)The calculated investment costs of a pump includingmotor, control, and pump are shown Fig. 1.28394 %Fig. 2. An example of lifetime costs of three different sizedpumps.