Pre-Study of WP 1.1. Heating of Existing Buildings by Low-Temperature District Heating

Transcription

1 Pre-Study of WP 1.1. Heating of Existing Buildings by Low-Temperature District Heating Hakan İbrahim Tol March 2013 Aalborg, Denmark

2 CONTENT My Background (Case Studies of my PhD Project) Design of DH network for new settlements Roskilde Fjernvarme Design of DH network for existing settlements Gladsaxe Fjernvarme Nominal Capacities for Non-Fossil-Fuel Heat Sources Pre-study WP 1.1 (4DH) Focus Relation to Other WPs Issues to be Considered Allocated time: 15 minutes

3 My Background Case Studies of PhD Project

4 TREKRONER LOW-ENERGY DH SYSTEM SEMI-DETACHED SINGLE FAMILY HOUSES Number of Houses 165 Low Energy House (Class I) 3 kw Space Heating 3 kw Domestic Hot Water (120 l buffer tank) NEW LOW ENERGY DH SYSTEM Static Pressure 10 bar Max Allowable Pressure Drop 8 bar Total Length of Network ~1 km Pipe Type (Class I) AluFlex Twin Pipe DN14 DN32 Steel Twin Pipe DN32 DN80 2/15

5 DIMENSIONING METHOD (NOT A RULE-OF-THUMB) 8 bar 8 bar 8 bar Nonlinear Constraint Function Optimization 8 bar Objective Function: Min Heat Loss from DH Network 8 bar By Means of: Reducing Each Diameter 8 bar 8 bar Constraint Functions: Max Allowable Pressure Loss in each Route (8 bar) 8 bar 3/15

6 Length [m] LENGTH OF PIPE TYPES PG - Critical Max. Pressure Gradient Optimization %14 Less Heat Loss with Optimization Applied 4/15

7 CASE STUDY IN AN EXISTING AREA Natural Gas Heating System Low-Energy District Heating System 5/15

8 LOW-ENERGY DH SYSTEM DETACHED SINGLE FAMILY HOUSES Number of Houses 780 Heat Demand [kw] Heat Demand Type CS FS Space Heating Domestic Hot Water Total= PIPE TYPE (CLASS I) AluFlex Twin Pipe : DN14 DN32 Steel Twin Pipe : DN32 DN80 Single Pipe : DN100 DN200 LOW-ENERGY DISTRICT HEATING NETWORK Max Static Pressure : 10 bar Max Pressure Drop : 8 bar Total Length of Network : 9.3 km 6/15

9 Storage Tank (120 liter) SUBSTATION & IN-HOUSE INSTALLATION Substation Existing Radiator System Original Heat Capacity: 9 kw Space Heating Heat Supply Domestic Hot Water Current Heat Demand: 5.1 kw After Renovation 3 kw Space Heating 3 kw Domestic Hot Water 7/15

10 Domestic Hot Water Space Heating Return Temperature [ C] Mass Flow Requirement [kg/s] Return Temperature [ C] Mass Flow Requirement [kg/s] EXISTING RADIATOR SYSTEM 60 0, , , , CS - Return Temp. FS - Return Temp. CS - Mass Flow FS - Mass Flow Supply Temperature [ C] ,0208 0,0208 0,0208 0,0208 0,0207 0, DHW - Return Temp. DHW - Mass Flow Supply Temperature [ C] 8/15

11 Heat Load Factor [-] LOAD DURATION CURVE 1,5 1,0 Current Situation (Buildings without renovation) Future Situation (All buildings renovated) 0,5 0, Current Situation Low-Energy Number of Hours 9/15

12 Supply Temperature [ C] Mass Flow Requirement [kg/s] BOOSTING THE SUPPLY TEMPERATURE CURRENT SITUATION ,724 1,399 1,565 3, Duration [Hour] Heat Load Factor [-] Mass Flow (55 deg-c Supply) Mass Flow (Operational Planning) Supply Temperature (Current Situation) 10/15

13 Supply Temperature [ C] Mass Flow Requirement [kg/s] BOOSTING THE SUPPLY TEMPERATURE FUTURE SITUATION ,724 1,399 1,565 3, Duration [Hour] Heat Load Factor [-] Mass Flow (55 deg-c Supply) Mass Flow (Operational Planning) Supply Temperature (Future Situation) 11/15

14 Length [m] COMPARISON OF LENGTH OF PIPE TYPES Alu Flex 14/14 Alu Flex 16/16 Alu Flex 20/20 Alu Flex 26/26 Alu Flex 32/32 Twin Pipe 32/32 Twin Pipe 40/40 Twin Pipe 50/50 Twin Pipe 65/65 Twin Pipe 80/80 Single Pipe 100 Single Pipe 125 Single Pipe 150 Single Pipe 200 Optimization Without Boosting Optimization With Boosting (Boosted Supply Temp.) 40% of Pipe Investment Cost can be saved with boosting supply temperature in peak periods 12/15

15 NON-FOSSIL FUEL HEAT SOURCES Ratio in Overall Heat Produced Heat Source WASTE HEAT FROM INDUSTRY 3 Theoretical potential of 139 PJ/year Biomass 15% 41.1% Natural Gas 30% 26.4% Coal 24% 22.4% GEOTHERMAL SOURCE 4 Potential: PJ/Year at 70 C Oil 7% 4.6% Wastes, Non Renewable 23% 5.6% CONDENSER HEAT FROM CHILLERS 5 Overall Heat Demand of Denmark 220 PJ Cooling Supermarket Chiller Heat Recovery 43 C [1] [2] [3] [4] [5] 13/27

16 OPTIMAL NOMINAL CAPACITIES 14/15 DH in Areas with Low Energy Houses 20/12/2011

17 4DH RESEARCH ACTIVITIES

18 Storage Tank (??? liter) DETAILED SIMULATION FOR WP 1.1. (4DH) Space Heating Original Heat Capacity:? kw Heat Supply Domestic Hot Water Current Heat Demand:? kw? kw Space Heating? kw Domestic Hot Water WP 1.2. Various methods to avoid legionella (boundary condition to WP 1.1.) WP 1.1. Dynamic simulations for typical buildings -with various supply temperature levels -with various levels of radiator sizes/heat demand WP 1.3. Input data from both WPs Required Mass Flow (heat demand) 15/15

19 THANK YOU!