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, EstoniaIt was concluded that replacing the PEX pipes in theprimary network and post-insulated pipes in the crawlspaces of houses in the areas identified as ―hotspots‖was the most effective strategy for heat loss reduction.DEFINING KEY PERFORMANCE INDICATORSThe main goal of SlimNet is improving networkefficiency as part of the new business plan that setscourse for a future proof company which providessustainable, cost-effective and 80% renewable heat.The Key Performance Indicators (KPI‘s) can be dividedin four main criterions:1. Economics2. Sustainability3. Reliability4. Customer SatisfactionEconomicsEvery GJ of heat lost in the network cannot be sold andhas therefore a negative effect on the balance sheet.Consequently the heat loss in the DH-network is anobvious and important KPI.Another parameter that has a negative effect onprofitability is the amount of water that is replenished.SustainabilityThe avoided CO2-emissions are and should be animportant driver for DH grids. According to subsequentdirectives in the Netherlands for assessing energyperformance of buildings NEN 7120, the avoidedCO2-emissions has to be determined on the requiredprimary energy sources and by referring to commonstate-of-the-art technologies. The HR-107 type (107%LHV efficiency) is the required and accepted commonstate-of-the-art reference technology.ReliabilityThe condition of the network in terms of reliabilitypresents itself in the amount of times that mechanicshave to deal with unplanned repairs. It was apparentthat SVP was facing an increasing trend curve. Theactual deprecation of the replaced piping provided aanother criterion for assessing system degradation.Customer satisfactionReducing off time, during replacement was animportant element of the SlimNet approach.KPI summary1. Heat loss2. Water replenishment3. Avoided CO 2 emissions4. Unplanned repairs5. Network degradation6. Off-time during replacementDEVELOPING ANALYZING TOOLSResearch had located the ―hotspots‖ of unplannedrepairs and heat loss in an area of 4000 houses. These―hotspots‖ were responsible for 50% of the unplannedrepairs. In order to define and implement a suitable andcost-effective replacement strategy a set of tools wasdeveloped.Upgraded network diagramAnalyzing networks requires reliable andcomprehensive network diagrams. All requiredinformation such as dimensions, age, depth etc. shouldbe available in the diagram. Many network diagramsare drawn using CAD-software. Analyzing from thosedrawings is costly. It therefore was chosen to revise thediagram completely and apply the possibility to addelement attributes to the drawing connected to anintegral database system. The upgraded networkdiagram had a catalytic effect on two other models, thenetwork model and the grid valuation model.Network modelIn 2009 SVP replaced the outdated and inadequatenetwork with a validated dynamic model (TERMIS),developed by 7-Technologies with COWI as systemintegrator. With the upgraded network diagram SVPhad the first and validated model of the primarynetwork within five months.In combination with a new CRM system, operationalsince 2010, SVP will soon be able to tap into theinformation on customer behavior and consumption.This will allow SVP to dynamically calculate the currentstate of flow, pressure and temperature throughout thenetwork at a configurable cycle time. Additionally, everyreal-time model calculation cycle will include a forecastsimulation for a given period. This allows SVP to beabreast of demands, enabling optimization ofoperations and planning of the future.Valuation modelThe upgraded network diagram supplied databaseinformation on lengths, dimensions, age and type. Withthe following equations added to the database it waspossible to develop a valuation model, that could helpto prioritize and direct renovation efforts.networkX R L xx1network D AY x1 DxxRx Lx(2)(3)55