1. Slides 4- Energy analysis ENERGY ANALYSIS

2. Slides 4 – Energy analysis Structure of a company's energy system SupplyConversionDistributionConsumption Heat recovery Disposal

3. Slides 4 – Energy analysis Energy efficiency Typical areas of improvement  Cooling/refrigeration  Heating  Compressed air  Insulation  Heat recovery  Separation processes  Lighting ...

4. Slides 4 – Energy analysis Efficient energy use Not only a question of best technology!

5. Slides 4 – Energy analysis Energy management  Organization Set up an organizational unit, identify responsibilities and determine the budget  Analysis and Inventory and description Planning of the energy situation search for energy saving options  Control Control of the energy plants, work out energy indicators  Consulting Energy reports, internal consulting and market analysis  Implementation Implementation of energy saving options maintenance of energy plants

6. Slides 4 – Energy analysis Documentation of load curves Documentation of curves for  A year  A week  A day Analysis of load curves  Winter – summer ratio  Combined use of heat and power  Switched off or reduced operation at weekends  Days with high energy demand  Bottlenecks  Energy demand after production

7. Slides 4 – Energy analysis Annual energy consumption Collection and documentation for all energy carriers  Quantity  Cost  Reference quantities  Definition of indicators Analysis and interpretation  Distribution of quantities  Distribution of costs  Variation of indicators  Comparison of indicators with other companies or publications

8. Slides 4 – Energy analysis Analysis of consumers Heat  Thermostatic valves  Separate control of plants  Adequate temperatures  No internal sources of heat and humidity in cooled areas  Use shades for heat protection  Frequency-controlled fans  Use heat cascades ... Electric power  Avoid partial load and use adequate machines  Adapt power (e. g. fans)  Optimize lights (cleaning, modern lighting, analyse demand)  Clean and service (air filter, nozzles, etc.)  Compressor location and pressure  Peak load management

9. Slides 4 – Energy analysis Heat losses detected with an infrared camera

10. Slides 4 – Energy analysis Specific energy consumption Example: Energy consumption of a brewery Indicator: MJ/hl Measure: June 1992 Installation of a vapour recompression plant 150 100 125

11. Slides 4 – Energy analysis Energy, work and power  Work is the transmission of energy.  The unit of work and energy is JOULE.  The speed at which work is performed is power [J/s = W].

12. Slides 4 – Energy analysis Heat capacity To heat up a body with a mass of m by  T, the following amount of heat is required: Q = c m  T The specific heat capacity c of the material depends on the temperature. The specific heat capacity is the amount of energy required to heat up 1 kg of material by 1 °C.1 °C Unit: [c] = 1 J.kg -1.K -1 Gold Iron Oxygen Benzene Water Specific heat capacity

13. Slides 4 – Energy analysis The performance of 1 kWh 367 m  Lifts 1 ton of steel by 367 m! 60 km/h305 km/h  Accelerates a car (1 ton) to approx. 60 km/h (without losses 305 km/h)! 0.86 °C  Heats up 1 000 l of water by 0.86 °C! Source: Karl Lummerstorfer, Energie Institut Linz

14. Slides 4 – Energy analysis Efficiency in a steam system 85 – 98%Heat exchange 75 – 90%Steam transportation (70-) 82 – 90%Steam boiler EfficiencyPart of the steam system

15. Slides 4 – Energy analysis Steam system  Reduce leaks.  Improve operation of steam traps.  Increase condensate recovery.  Increase flash steam recovery.  Use lower steam pressure if possible.  Use direct steam for heating if possible.

16. Slides 4 – Energy analysis Cooling process Consequences:  The lower the temperature difference the better:  Check the necessary cooling temperature  Allow the temperature in the condenser to be as low as possible (e.g. water cooling)  Maintain the heat exchanger (especially evaporator) ...  The higher the cooling temperature the better  Others:  Remove water from ground  Avoid high temperature of the incoming product ... Efficiency = Q cond. / P ~ T cond. / (T cond. – T evap. ) Q: Heat P: Power T: Temperature

17. Slides 4 – Energy analysis Cooling process M QoQo QuQu P ToTo TuTu Q u = Q o + P Efficiency = Q o / P = T o / (T u – T o ) Evaporator Compressor Condenser High pressureLow pressure Collector

18. Slides 4 – Energy analysis Cooling and freezing  Raising the cooling temperature by 1 °C saves approx. 4% of electric energy.  Choose the adequate temperature: frozen meat at -20 °C, cooling at 0 °C to 4 °C.  Clean the condenser regularly and provide sufficient cool air supply.  Use the capacity of the storage rooms, collect goods, switch off unused cooling units.  Keep storage rooms closed to avoid entrance of humidity and warm air.  Defrost cooling rooms.

19. Slides 4 – Energy analysis Cooling – 2  Insulation  Recommendations for PU-foam insulation: Insulation thickness  Evaporator:  Optimize defrosting  Compressor  Close to evaporator  Central location makes servicing and use of heat easier  Condenser:  Outside of building, sun-protected  Clean regularly  Use R134 a, R22 or ammonia 0 to -8 °C 0 to -15 °C below -15 °C 80mm 110mm 150mm

20. Slides 4 – Energy analysis 8 TiTi ToTo TdTd Q1Q1 Q2Q2 Q4Q4 Q3Q3 QTQT Fresh air drying Fresh air drying with heat recovery Circulating air drying with/without heat recovery Heat recovery with condensation of humidity (heat pumps, thermo-compression) Drying process Typical options for improvement: Q 1 = Insulation of drier Q 2 = Pre-drying, pre-concentration of the product Q 3 = Control of temperature and humidity Q 4 = Heat recovery, humidity control of flue gas, good housekeeping

21. Slides 4 – Energy analysis Compressed air  Shut down compressor, drier and the network  Reduce the pressure level (as far as possible)  Avoid leakages  Lower the temperature of incoming air  Avoid compressed air for cleaning  Carry out maintenance  Use electrically-driven equipment  Foster heat recovery Source: Karl Lummerstorfer, Energie Institut Linz

22. Slides 4 – Energy analysis Lighting  Turn off when not needed  Use timer or motion detector  Use daylight as much as possible  Service and clean  Clean windows, ensure efficient design of rooms  Use energy saving bulbs

23. Slides 4 – Energy analysis Heat recovery cooling units – 1 Compressor EvaporatorAir-cooled condenser Water-cooled condenser

24. Slides 4 – Energy analysis Heat recovery cooling units – 2

25. Slides 4 – Energy analysis ECOPROFIT-company: Brewery Annual production: > 1 million hl, ISO 14000  Saving of water, energy and chemicals due to CP options:  Cold filtering/sterilization  New filling line  Heat/power co-generation  Vapour compression ...

26. Slides 4 – Energy analysis Specific heat consumption of a brewery 0.00 10.00 20.00 30.00 40.00 50.00 in kWh/hl spec. heat 38.6040.6747.3042.6241.4237.5634.1929.9127.5824.47 19931994´95´96´97´98´99200020012002

27. Slides 4 – Energy analysis Multistage evaporation Source: Ignatowitz 1994 1. evaporator 1. concentrate steam feed steam condensate 1. vapour condensate 2. vapour condensate 3. vapour condensate 2. evaporator 2. concentrate 3. evaporator final concentrate condenser vacuum pump 1. vapour2. vapour3. vapour

28. Slides 4 – Energy analysis Evaporation with vapour compression concentrate feed solution pre-heater preheated feed evaporator compressor vapour vapour- condensate steam (start-up) Source: Ignatowitz 1994