Emerson Energy Efficiency Guide ©2013 Emerson. All rights reserved.6
Contents
8 The Impact of Maintenance Practices on
Energy Performance ....................................................................................
54
9 Making a Step-change: Opportunities, Auditing
and Improvement Projects ..........................................................................
56
9.1 The Energy Walkthrough ................................................................................................................57
9.2 Energy Projects – Identification and Assessment ..........................................................................57
9.2.1 Team and Preparation .....................................................................................................................58
9.2.2 Assessment Process and Operational Reviews ............................................................................. 58
9.2.3 Project Generation and Validation .................................................................................................. 59
9.3 Ongoing Improvement – The Mature Operation ............................................................................59
9.4 Financial Planning and Project Economics .................................................................................... 60
9.4.1 Standard Project Economics Techniques ......................................................................................60
9.4.2 Utilities Marginal pricing .................................................................................................................62
9.4.3 Investment Thresholds for Energy Projects ...................................................................................63
10 Common Energy Tools and Techniques .....................................................64
10.1 Measurement and Control of Energy Streams ............................................................................... 64
10.1.1 Mass and Energy Balances ............................................................................................................64
10.1.1.1 Feed and Product streams .............................................................................................................65
10.1.1.2 Steam ..............................................................................................................................................65
10.1.1.3 Fuels ................................................................................................................................................65
10.1.1.4 Electrical Power Measurements .....................................................................................................66
10.1.2 Process Control ..............................................................................................................................66
10.1.2.1 Controller Tuning and Basic Set-up. ...............................................................................................66
10.1.2.2 Feed-Forward Control ..................................................................................................................... 67
10.1.2.3 Constraint pushing control .............................................................................................................68
10.1.2.4 Model Predictive Control (MPC) .....................................................................................................69
10.2 Utilities Systems .............................................................................................................................. 71
10.2.1 Steam Generation ........................................................................................................................... 71
10.2.1.1 Boiler Feed Water Preheat .............................................................................................................71
10.2.1.2 Deaerator operation ........................................................................................................................ 72
10.2.1.3 Minimising Blowdown ..................................................................................................................... 73
10.2.1.4 Condensate Collection and Heat Recovery ...................................................................................74
10.2.2 Steam Networks and Distribution Optimisation .............................................................................74
10.2.2.1 Utilities Optimisation ......................................................................................................................75
10.2.2.2 Structural changes - Steam blending ............................................................................................. 76
10.3 Combustion Activities .....................................................................................................................76
10.3.1 Installed Equipment ........................................................................................................................77
10.3.1.1 Upgrade natural draught to forced draught operation...................................................................77
10.3.1.2 Improved combustion air-preheat ..................................................................................................77
10.3.1.3 Burner upgrades – low NO
x
and turndown ....................................................................................78
10.3.2 Furnace Control ..............................................................................................................................78