Calculating Heat Energy Requirements Sham Kashyap Computing and - PowerPoint PPT Presentation

Calculating Heat Energy Requirements Sham Kashyap Computing and Information Sciences Kansas State University

Overview � Introduction � Equations � Graphical Analysis � Issues � Other Applications � Discussion

Introduction � H.T.C is a software program coded in Visual Basic using Microsoft Visual Studio .NET. � It calculates � The amount of energy and fuel needed for the heat treatment of the facility. � Provides a graphical analysis of variations of fuel consumption with respect to changes in temperature and duration of heat treatment.

Equations � Surfaces =∆ × × q T Area U S ∆ T: Temperature difference of the ⎛ ⎞ or exposed wall. ⎜ ⎟ 1 U: Coefficient of heat transfer of =∆ × ×⎜ ⎟ q T Area the material. S x ⎜ ⎟ k : Thermal Conductivity ⎝ ⎠ x: Thickness k Equation applied to walls, windows, doors, ceiling and floor

Equations � Infiltration =∆ × × × 0.018 q T Volume aircirculations I � Steel =∆ × × 0.12 q T Steelweight St � Total ∑ = + + q q q q Total S I St

Equations � Fuel consumption ⎛ ⎞ 1 q = × q ⎜ ⎟ Total Fuel unit is the amount of energy ⎝ ⎠ q efficiency unit produced by the fuel per unit � The required energy is converted into fuel consumption to estimate the cost of energy needed

Equations � In the software, the user has the option of � Changing efficiency values of fuels suiting the machinery used for heat up. � Choosing Raise and Peak Phases of the heat treatment � Adding new structural materials, fuels to the database

Graphical Analysis using HTC � It can be used to predict the effects of a particular variation in heat treatment setting. � In this sense, it is a tool to virtually compare two heat treatments on a building with different temperature and fuel settings. � In this presentation, we take up an example and run the various analysis tools.

Facility Description Rooms: Floor 1: 3 Steel : 3000 Pounds Floor 2: 2 Volume: 175616 Cubic Feet Floor 3: 4 Air circulations per hour: 3 Floor 4: 2 Temperature Settings: Target Temperature 140 F Outside 75 F Target Rate of Increase 5.4 Inside 80 F F/ hr Ground 65 F in temperature Period 48 Hours

Cost of fuels � Effects of variation in target temperature Target Temperature Vs Cost 1200 Cost of Energy Source ($) 1000 800 Electricity Propane 600 Natural Gas 400 200 0 100 104 108 112 116 120 124 128 132 136 140 144 148 Required Temperature (F)

Cost of fuels � Effects of variation in duration of heat treatment Duration of treament Vs Cost 1600 Cost of Energy Source ($) 1400 1200 1000 Electricity Cost 800 Propane Cost 600 Natural Gas Cost 400 200 0 24 29 34 39 44 49 54 59 64 69 Duration

Cost of fuels � Effects of variation in starting temperature Starting Temperature Vs Cost 1600 Cost of Energy Source ($) 1400 1200 1000 Electricity Cost 800 Propane Cost 600 Natural Gas Cost 400 200 0 32 38 44 50 56 62 68 74 80 86 92 98 Starting Temperature (F)

Fuel consumption � Effects of variation in target temperature Target Temperature Vs Fuel Consumption Target Temperature Vs Electricity Requirement 14000 700 12000 600 Fuels (Gallons) Electricity (kwh) 500 10000 Propane Req 400 8000 Number2 Oil Req Electricity 300 6000 Number6 Oil Req 200 4000 100 2000 0 0 100 105 110 115 120 125 130 135 140 145 150 100 104 108 112 116 120 124 128 132 136 140 144 148 Target Temperature (F) Temperature (F)

Fuel consumption � Effects of variation in target temperature Target Temperature Vs Natural Gas Target Temperature Vs Steam requirement Steam at 15 psg, 50% efficiency 100 700 Thousands 90 600 Natural Gas (therm) 80 500 70 (pounds) 60 400 Natural Gas 50 Steam 300 40 30 200 20 100 10 0 0 100 104 108 112 116 120 124 128 132 136 140 144 148 100 105 110 115 120 125 130 135 140 145 150 Temperature (F) Temperature (F)

Fuel consumption � Effects of variation in starting temperature Starting Temperature Vs Fuel Consumption Starting Temperature Vs Electricity Requirement 1000 20000 900 18000 16000 800 Electricity (kwh) Fuels (Gallons) 14000 700 Propane Req 12000 600 10000 Electricity Number2 Oil Req 500 8000 Number6 Oil Req 400 6000 300 4000 200 2000 100 0 0 32 38 44 50 56 62 68 74 80 86 92 98 32 39 46 53 60 67 74 81 88 95 Temperature (F) Starting Temperature (F)

Fuel consumption � Effects of variation in starting temperature Starting Temperature Vs Natural Gas Starting Temperature Vs Steam requirement Steam at 15 psg, 50% efficiency 1000 140 Thousands 900 120 Natural Gas (therm) 800 100 700 (pounds) 600 80 500 Natural Gas Steam 60 400 300 40 200 20 100 0 0 32 38 44 50 56 62 68 74 80 86 92 98 32 38 44 50 56 62 68 74 80 86 92 98 Temperature (F) Temperature (F)

Energy absorption in different materials � Effects of variation in target temperature Target Temperature Vs Heat supply 45 Millions Total Heat Req in 40 BTUs Heat Requirement 35 Grnd Heat Req 30 25 Roof Heat Req 20 15 Infil Heat Req 10 5 SteelHeat Req 0 100 105 110 115 120 125 130 135 140 145 150 WallsHeat Req Temperature

Energy absorption in different materials � Effects of variation in starting temperature Starting Temperature Vs Heat supply 70 Millions Total Heat Req in BTUs 60 Heat Requirement Grnd Heat Req 50 40 Roof Heat Req 30 20 Infil Heat Req 10 SteelHeat Req 0 2 9 6 3 0 7 4 1 8 5 3 3 4 5 6 6 7 8 8 9 WallsHeat Req Temperature

Issues � Heat absorption by different materials � Un-accountable losses � Correction factor � Effects of humidity and pressure � Model verification

Heat Absorption and Temperature Rise Variations in Heat Absorption 190 170 150 Temperature (F) 130 110 Steel Structure 90 Ambient 70 50 Start Rise Peak Start Peak Fall Time

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Other Applications � How to reach a trade off between amount of fuel used, target temperature, peak temperature duration. � If using multiple sources of energy, how to share energy requirement. � Insect Mortality.

References William H. Severns, Julian R. Fellows, “ Heating, Ventilating 1. and Air Conditioning Fundamentals ” Second Edition, John Wiley & Sons, Inc 1949. Burgess H. Jennings, “ The Thermal Environment ” Harper & 2. Row, 1978. Thomas J. Imholte,” A guide to the Sanitary Design of Food 3. Plamsts and Food Plam Equipment, Engineering for Food Safety and Sanitaion “ Second Edition

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