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Calculating Heat Energy Requirements
Sham Kashyap Computing and Information Sciences Kansas State University
Overview
Introduction Equations Graphical Analysis Issues Other Applications Discussion
Calculating Heat Energy Requirements Sham Kashyap Computing and - - PowerPoint PPT Presentation
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
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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
- f fuel consumption with respect to
changes in temperature and duration of heat treatment.
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Equations
Surfaces
S
q T Area U =∆ × ×
∆T: Temperature difference of the exposed wall. U: Coefficient of heat transfer of the material. k: Thermal Conductivity x: Thickness
1
S
q T Area x k ⎛ ⎞ ⎜ ⎟ =∆ × ×⎜ ⎟ ⎜ ⎟ ⎝ ⎠
- r
Equation applied to walls, windows, doors, ceiling and floor
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Equations
Infiltration
0.018
I
q T Volume aircirculations =∆ × × ×
Steel
0.12
St
q T Steelweight =∆ × ×
Total S I St
q q q q = + +
∑
Total
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Equations
Fuel consumption
1
Total unit
q Fuel q efficiency ⎛ ⎞ = × ⎜ ⎟ ⎝ ⎠
unit
q
is the amount of energy produced by the fuel per unit
The required energy is converted into fuel
consumption to estimate the cost of energy needed
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Equations
In the software, the user has the
- ption 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
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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.
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Facility Description
Rooms: Floor 1: 3 Floor 2: 2 Floor 3: 4 Floor 4: 2 Steel : 3000 Pounds Volume: 175616 Cubic Feet Air circulations per hour: 3 Temperature Settings: Outside 75 F Inside 80 F Ground 65 F Period 48 Hours Target Temperature 140 F Target Rate of Increase 5.4 F/ hr in temperature
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Cost of fuels
Effects of variation in target
temperature
Target Temperature Vs Cost
200 400 600 800 1000 1200 100 104 108 112 116 120 124 128 132 136 140 144 148 Required Temperature (F) Cost of Energy Source ($) Electricity Propane Natural Gas
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Cost of fuels
Effects of variation in duration of heat
treatment
Duration of treament Vs Cost
200 400 600 800 1000 1200 1400 1600 24 29 34 39 44 49 54 59 64 69 Duration Cost of Energy Source ($) Electricity Cost Propane Cost Natural Gas Cost
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Cost of fuels
Effects of variation in starting
temperature
Starting Temperature Vs Cost
200 400 600 800 1000 1200 1400 1600 32 38 44 50 56 62 68 74 80 86 92 98 Starting Temperature (F) Cost of Energy Source ($) Electricity Cost Propane Cost Natural Gas Cost
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Fuel consumption
Effects of variation in target temperature
Target Temperature Vs Electricity Requirement 2000 4000 6000 8000 10000 12000 14000 100 104 108 112 116 120 124 128 132 136 140 144 148 Temperature (F) Electricity (kwh) Electricity Target Temperature Vs Fuel Consumption 100 200 300 400 500 600 700 100 105 110 115 120 125 130 135 140 145 150 Target Temperature (F) Fuels (Gallons) Propane Req Number2 Oil Req Number6 Oil Req
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Fuel consumption
Effects of variation in target
temperature
Target Temperature Vs Steam requirement
10 20 30 40 50 60 70 80 90 100 100 105 110 115 120 125 130 135 140 145 150 Thousands Temperature (F) Steam at 15 psg, 50% efficiency (pounds) Steam
Target Temperature Vs Natural Gas
100 200 300 400 500 600 700 100 104 108 112 116 120 124 128 132 136 140 144 148 Temperature (F) Natural Gas (therm) Natural Gas
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Fuel consumption
Effects of variation in starting
temperature
Starting Temperature Vs Fuel Consumption 100 200 300 400 500 600 700 800 900 1000 32 39 46 53 60 67 74 81 88 95 Starting Temperature (F) Fuels (Gallons) Propane Req Number2 Oil Req Number6 Oil Req Starting Temperature Vs Electricity Requirement 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 32 38 44 50 56 62 68 74 80 86 92 98 Temperature (F) Electricity (kwh) Electricity
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Fuel consumption
Effects of variation in starting
temperature
Starting Temperature Vs Natural Gas
100 200 300 400 500 600 700 800 900 1000 32 38 44 50 56 62 68 74 80 86 92 98 Temperature (F) Natural Gas (therm) Natural Gas
Starting Temperature Vs Steam requirement
20 40 60 80 100 120 140 32 38 44 50 56 62 68 74 80 86 92 98 Thousands Temperature (F) Steam at 15 psg, 50% efficiency (pounds) Steam
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Energy absorption in different materials
Effects of variation in target
temperature
Target Temperature Vs Heat supply
5 10 15 20 25 30 35 40 45 100 105 110 115 120 125 130 135 140 145 150
Millions
Temperature Heat Requirement Total Heat Req in BTUs Grnd Heat Req Roof Heat Req Infil Heat Req SteelHeat Req WallsHeat Req
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Energy absorption in different materials
Effects of variation in starting
temperature
Starting Temperature Vs Heat supply
10 20 30 40 50 60 70 3 2 3 9 4 6 5 3 6 6 7 7 4 8 1 8 8 9 5
Millions
Temperature Heat Requirement Total Heat Req in BTUs Grnd Heat Req Roof Heat Req Infil Heat Req SteelHeat Req WallsHeat Req
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Issues
Heat absorption by different
materials
Un-accountable losses Correction factor Effects of humidity and pressure Model verification
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Heat Absorption and Temperature Rise
Variations in Heat Absorption
50 70 90 110 130 150 170 190 Start Rise Peak Start Peak Fall Time Temperature (F) Steel Structure Ambient
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Screenshots
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Screenshots
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Screenshots
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Screenshots
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Screenshots
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Other Applications
How to reach a trade off between amount
- f fuel used, target temperature, peak
temperature duration.
If using multiple sources of energy, how
to share energy requirement.
Insect Mortality.
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References
1.
William H. Severns, Julian R. Fellows, “Heating, Ventilating and Air Conditioning Fundamentals” Second Edition, John Wiley & Sons, Inc 1949.
2.
Burgess H. Jennings, “The Thermal Environment” Harper & Row, 1978.
3.
Thomas J. Imholte,”A guide to the Sanitary Design of Food Plamsts and Food Plam Equipment, Engineering for Food Safety and Sanitaion “ Second Edition
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