MODULE M4

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• MODULE M4
• How to perform an EINSTEIN energy audit?

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Contents

• Introduction to the Einstein thermal energy audit
  methodology
• Steps of the methodology

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EINSTEIN Audit Methodology
PRE AUDIT (steps 1 - 4)
AUDIT (steps 5 - 6)
EVALUATION OF ALTERNATIVES (steps 7 - 9)
PROPOSAL (step 10)
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10 EINSTEIN Audit steps
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Pre-Audit Steps 1-4
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PRE AUDIT STEP 1
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STEP 1 Motivate

• Objective Create interest for energy efficiency
• How ?
• Send EINSTEIN information material to the company
• EINSTEIN road show
• EINSTEIN promotional brochure
• EINSTEIN technical brochure
• EINSTEIN good practice examples
• Some results of previous EINSTEIN audits
• Contact directly after some time
• Try to address to the right contact person
• Who is the right person? managing director,
  energy manager,
• find out! Collect information on the staff
  before

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PRE AUDIT STEP 2
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STEP 2.1 Pre-audit data acquisition

• Preparation of the company
• -gt they should collect the following
  information
• General situation of the company
• Fuel and electricity bills
• Description of the production process (flowchart
  with temperatures and mass flows)
• Description of the different processes
• Description of the heat and cold supply system
• Description of the buildings, production halls
  and stores

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STEP 2.2 Pre-audit data acquisition

• Preparation of the auditor
• most relevant processes in a typical industry of
  the sector ? Which processes consume most energy?
• existing options for process technologies ? Which
  are their advantages and disadvantages ?
• Sources of information
• EINSTEIN tool-kit links for fast access to basic
  information
• Web links and bibliography in Einstein reports
  and website Area Download, www.iee-einstein.org
• Energy Wikipedia http//energy-in-industry.joanne
  um.at

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STEP 2.3 Pre-audit data acquisition

• By distance data acquisition
• Basic questionnaire
• paper format
• electronic format
• (directly importable in the EINSTEIN tool)
• Explanatory text
• Advantages
• Rough preliminary estimation possible before
  visit
• Checklist of most relevant additional data that
  should be obtained

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PRE AUDIT STEP 3
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STEP 3.1 Processing of preliminary information

• Processing of pre-audit data with EINSTEIN tool
• EINSTEIN tool will support you with
• List of severe inconsistencies of data
• List of missing necessary data that can neither
  be computed nor estimated

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STEP 3.2 Telephonic interview

• Complete information (gathered in Step 3.1)
• by telephonic interviews
• Main products and quantities
• Amount of total energy consumption
• Identification of most heat / cold consuming
  processes
• Main heat / cold supply equipment
• Temperature levels in the heat supply and
  processes

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STEP 3.3 Benchmark data

• Acquisition of benchmark data
• Consumption of similar industries
• Best practice reference values
• Data sources
• Database of EINSTEIN tool
• Referenced documents in EINSTEIN reports and
  website Area Download, www.iee-einstein.org
• Energy Wikipedia http//energy-in-industry.joanne
  um.at

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STEP 3.4 Basic knowledge on specific industry

• Acquisition of basic knowledge on the industry
• Specific machineries and possible technological
  alternatives
• Specific supply equipments/systems and possible
  technological alternatives
• Identification of possible measures
  documentation on best available technologies
  (BAT)
• Sources
• EINSTEIN Tool
• Web links and bibliography in EINSTEIN reports
  and website Area Download, www.iee-einstein.org
• Energy Wikipedia http//energy-in-industry.joanne
  um.at

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STEP 3.5 List of possible measures

• Make a list of possible measures
• Fast audit with the EINSTEIN tool (auto-design)
• Information sources on best available
  technologies (BAT)
• Experience from similar industries

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STEP 3.6 Processing of preliminary information

• Objectives
• Fast audit gt focus on the essential data
• Detailed audit gt do not forget the important
  data
• Make a list of priorities for further inquiry!
• Focus on the probably possible solutions
• Avoid collecting unnecessary information
• But insist on getting important information,
  even if access is difficult

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PRE AUDIT STEP 4
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STEP 4.1 Pre-evaluation report

• Pre-evaluation report generation
• Identification of the most relevant heat and cold
  consuming processes and approximate energy
  consumption
• First quantitative analysis of demand by
  temperature levels, time schedules, cumulative
  demand curves
• Identification of possible technological options
  for efficient heat and cold supply
• Order of magnitude and dimensioning of heat and
  cold supply equipments
• Estimation of expected energetic and economic
  performance

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STEP 4.2 Present pre-evaluation report

• Create report with the EINSTEIN tool
• Check validity of data on equipment costs stored
  in the tool databases
• Approximate first figures may convince company to
  go ahead with the audit and to deepen the
  analysis
• Do not promise too much at the beginning !
• Results depends on local conditions and on the
  accuracy on the basic information

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Energy Audit Steps 5-6
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ENERGY AUDIT STEP 5
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STEP 5.1 Present quickdirty study
Optional

• Present and discuss quick-and-dirty study
• May be starting point for your visit
• A summary of the already gathered data can be
  done
• Preliminary orientative conclusions can be
  presented
• Dont tell too much solutions and dont promise
  too much

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STEP 5.2 interviews and walk through

• Data collection in the office
• Assure that technical staff is present
• Use EINSTEIN basic questionnaire as a guide
• Ask for the following information
• ()

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STEP 5.2 Types of data

• General information
• annual production,
• which processes? How do they run?
• global figures (turnover, number of workers,)
• shifts, holiday periods,
• plans for the future?
• Fuel and electricity bills and energy tariffs
• Try to get information for several years !!!
• sharing of consumption by processes
• equipments
• production lines

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STEP 5.2 Types of data
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STEP 5.2 Types of data

• Data on processes
• Often the overall energy consumption is
  available, but not the split-up of the data by
  processes! Additional data is necessary
• Fluid/energy inflow and outflow
• Volume or mass and temperatures
• Mass or volume to be heated at start-up
• Number of batches or breaks, initial temperature
  from which equipment has to be heated
• Thermal losses of process equipment in operation
• Power requirement of process to maintain given
  temperature may be composed of thermal losses,
  phase-change of working fluids, chemical
  reactions

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STEP 5.2 Types of data

• There is no time to measure all data!!!
• Some hints for indirect calculations
• calculation of thermal losses
• from cool-down temperature and time
• or from approximate size and insulation thickness
• e.g. in drying process calculate the heat for
  evaporation from the difference of humidity in
  wet and dry product, etc.

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STEP 5.2 Types of data

• Data on heat and cold supply equipments
• get not only nominal power, but also operating
  hours, load factor, losses
• make a block diagram which equipment supplies
  which process
• Data on heat and cold distribution and storage
• get data on length, diameter, insulation of
  pipes, temperatures, pressure levels, flow rates
• This helps to calculate the energy consumption
• identify heat storage volume, temperature level,
  pressure, insulation, inlet and outlet flow rates
  
• Existing heat recovery systems
• identify existing heat exchangers for heat
  recovery (technical data, type e.g. plate HEX)
• estimate (typical) real operating conditions
  (flow rates, temperatures)

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STEP 5.2 Types of data

• Renewable energies
• identify available area (roof and ground),
  distances and orientation
• assess availability of biomass or biogas (from
  processes or vicinity)
• is there any motivation for renewables besides
  economics?
• Building heat cold demand
• make an inventory of existing buildings (offices,
  storage halls and production halls) heating
  systems and air-conditioning
• temperature levels and schedules of use
• sketches of buildings

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STEP 5.2 Types of data

• Economic and financial parameters
• identify OM costs
• how are investments in energy supply financed
  (externally, internally, contracting)?
• what are the requirements about pay-back or
  return rates?

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STEP 5.2 On-site walk-through audit
Walk through factory installations

• Make sure you visit at least all relevant
  processes
• Make photos (ask for allowance) and sketches
• Deepen your insight in how different processes
  work
• Try to anticipate possible problems with changes
  you already have in mind
• Possible integrations/connections of new
  equipments
• Available space for new equipments or storage
  tanks
• Get in touch with maintenance staff -gt try to get
  valuable information from everyday practice
• Average temperatures in storage tanks, etc.
• Ask for ideas from staff (workers who are working
  on the machine)

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STEP 5.3 On-site data check

• Fast on-site completeness and consistency check
  with the EINSTEIN tool
• Are data consistent?
• Are relevant data missing?
• You can ask for the missing relevant data
  on-site
• But try to avoid expensive measurements
  EINSTEIN will help you to estimate some figures

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STEP 5.4 Visit on site - METERING

• Fast measurements during walk through
• Temperature measurements
• e.g. wall temperature of vessels or pipes -gt
  operating temperatures, thermal losses
• Mass flow measurements
• Ultrasonic flow meters Measuring of flows by
  using a bucket

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STEP 5.4 Visit on site - METERING

• Measurements at the side of the process medium
  (secondary side)
• process medium (water, air, product flow) that is
  heated within the process
• fresh water added in a vessel, that is constantly
  heated to a temperature (e.g. in washing plants)

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STEP 5.4 Visit on site - METERING

• Measurements at the side of the heat supply
  (primary side)
• hot water supply line and temperatures before and
  after the heat exchanger (indirect energy supply)
• hot water supply line and temperature of hot
  water (direct energy supply)
• condensate lines
• of one or several processes
• fresh water added in the steam supply system

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STEP 5.5 Discuss impression from visit

• Define and decide with the company
• possible measures you want to analyse in detail
• measures you exclude a priori
• Fix some schedules (deadlines) for future steps
• delivery of additional information
• delivery of the audit report

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ENERGY AUDIT STEP 6
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STEP 6.1 Consistency check

• The data set gathered may be
• Incomplete
• (lack of data)
• Inconsistent
• (redundancy contradiction in data)
• Complete and consistent (Youre lucky!!)

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STEP 6.1 Consistency check
Type of information for data checking

• Mathematical and physical relationships
• Energy and mass balances on equipments and
  subsystems
• Second law constraints
• Physical properties of fluids and fuels
• Constraints on operating hours

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STEP 6.1 Consistency check
Type of information for data checking

• Engineering knowledge on typical values or
  practical limits
• Efficiencies
• Mathematically 0 lt eff lt 1
• Engineering typical (e.g.) 0.8 lt eff lt 0.9
  practial limits 0.6 lt eff lt 0.97
• Temperature differences in heat exchangers (HX)
• Heat loss coefficients
• Start-up times

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STEP 6.1 Consistency check

• Basic consistency checking based on
• Mathematical and physical relationships
• Practical limit values (engineering knowledge)
• Estimation of missing data (additionally) based
  on
• Typical values (engineering knowledge)

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EINSTEIN tool Consistency Check Module

• EINSTEIN makes the data set consistent

• EXAMPLE data available but not consistent
• Data entered into the questionnaire
• Natural Gas Annual Consumption 100.000 m3/a
• Final Energy Consumption 100.000 kWh (DATA
  ENTERING ERROR !!!)
• Low calorific value of Natural Gas 10 kWh/m3
• EINSTEIN detects that the proper value of the
  Final Energy Consumption is 1.000.000 kWh
• and replaces it !!

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STEP 6.1 Consistency check

• EINSTEIN automatically completes the data set
  necessary for the analysis of the present state
• Calculation of not explicitely given data (as far
  as possible)
• Required detail of information depends on
  expected quality of the results
• quickdirty study
• standard audit
• detailed audit

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STEP 6.2 Data estimation

• If still some basic data is missing, what to do ?
• Tell the company that with this information is
  impossible to make any reasonable proposal ?
• or
• Use typical values of engineering practice
• (estimate data option in EINSTEIN tool)
• Make some hypothesis and scenarios on the missing
  information. Try to get the limit cases.

• Important !
• Highlight in you report the type of estimations
  carried out

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EINSTEIN tool Consistency Check Module
INPUTS from the questionnaire
OUTPUTS to energy statistics
CC MODULE
Calculation of intermediate parameters
Results of calculation
Figures
Data check
Unknown parameters
Complete and consistent data set
Adjustment of data
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STEP 6.3 Breakdown of consumption

• Energy by process, equipment and fuel
• Reveals the priorities for the improvement
  efforts
• Energy by temperature level
• Permits to evaluate the potential for application
  of energy efficient technologies
• Analysis of primary energy consumption, CO2 and
  other emissions
• Permits to evaluate the environmental impact
• Specific energy consumption ratios
• Permits comparison with benchmarks and fixing
  realistic energy consumption targets

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STEP 6.3 Breakdown of consumption

• Temporal scale of analysis
• Annual data
• Main consuming processes and equipments
• General indications
• Monthly data
• Seasonal or ambient-temperature dependent
  variation of demand
• Hourly data
• Peak and base load analyisis
• Design of heat cold storage

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STEP 6.4 Real operation of equipments

• Energetic conversion efficiency
• Nominal values given in the technical
  documentation
• Input / output measuring estimate of fouling
  and malfunctions
• Measurement of exhaust gas to estimate conversion
  efficiency
• Heating and cooling capacities
• Technical documentation
• Input / output measuring
• Load factor / annual operating hours
• Comparison of instantaneous and annual input /
  output

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Step 6.5. Comparison with benchmarks

• EINSTEIN evaluates the company performances with
  respect to pre-defined benchmarks and targets
• Benchmark
• range (Bmin, Bmax)
• energy consumption of existing industries in a
  given sector
• Target
• value of energy consumption achievable with best
  available technologies

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Step 6.5. Comparison with benchmarks

• Types of benchmarks / targets
• Energy per unit economic value (energy
  intensity)
• Energy per unit quantity of final product
  (specific energy consumption by process)
• Energy per unit quantity of intermediate product
  processed (specific energy consumption by unit
  operation)

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Evaluation of Alternatives Steps 7 - 9
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EVALUATION OF ALTERNATIVES STEP 7
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STEP 7 Conceptual design of saving options and
draft energy targeting

• EINSTEIN thinks logical,
• therefore energy saving come first!
• On the demand side
• On the supply side

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STEP 7 Conceptual design of saving options and
draft energy targeting
Destillation
Cooling system
renewable energy
Process optimization
Heating system
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STEP 7 Conceptual design of saving options and
draft energy targeting

• Energy Saving steps
• Reduction of process heat demand through Process
  Optimisation
• Reduction of required heat supply by Heat
  Recovery and Process Integration
• Cogeneration and Polygeneration
• Efficient Energy Supply technologies and
  Renewable energy sources under exergetic
  considerations

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STEP 7.1 Process Optimization

• GOAL
• Energetic improvements of production processes
• Sources of energy efficiency measures
• BAT Reference Documents (BREFs)
• EINSTEIN report on Energy Auditing Practices and
  Tools
• Einstein Database

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STEP 7.2 Process Optimization

• ..a Database for energy efficiency
• General saving measures / methodologies
• E.g. cascaded use of washing water etc.
• Different technologies for 1 unit operation
• E.g. evaporation thermal vapour recompression,
  mechanical vapour recompression, vacuum
  evaporation etc.
• Efficiency measures that can be applied to
  specific technologies
• E.g. Waste heat recovery, optimised regulation in
  drying
• Applicability of technologies/measures to
  different sectors
• Enabling synergies between solutions applied in
  different sectors

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Steps 7.2 and 7.3 Heat Recovery

• Analysis of process streams
• Analysis of a minimal external heat and cold
  demand
• Potential for heat recovery
• Design and optimization of a heat exchanger
  network incl. storage
• Reduced energy demand and required temperature
  levels -gt basis for exergetic optimized
  integration of heat and cold supply

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Step 7.2 Heat recovery potential

• Goal
• Theoretical potential of energy savings by heat
  recovery (prior energy supply systems design)
• Save fuels and avoid over-dimensioning of supply
  equipments
• Methodology
• From energy supply and processes to streams
• Pinch Analysis
• Hot and cold composite curve
• Grand composite curve
• Results
• Theoretical heat recovery potential
• Necessary external heat/cold supply at the
  different temperature levels

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Step 7.2 Heat recovery potential

• From energy supply and processes to streams
• Process Washing
• Volume of vessel 5 m³
• Cold water Temperature 10C
• Process Temperature 60C
• Cold water input 10 m³/d
• Heat input during operation (heating of input
  water and thermal losses, evaporation negligible)
  90 kW
• Operation schedule
• Start-Up 600 h to 630 h
• Continuous operation 630 h to 1600 h
• Wastewater temperature 50C
• Temperature to which the wastewater can be cooled
  down 5C.

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Step 7.2 Heat recovery potential

• From energy supply and processes to streams
• Process Washing
• ? Enthalpy Streams

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Step 7.2 Heat recovery potential

• Pinch Analysis
• Hot and cold composite curve
• Grand composite curve

Source T. Gundersen. IEA. Process Integration,
www.tev.ntnu.no/iea/pi
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Step 7.3 Pre-design of heat exchangers network

• Goal
• Heat integration with a holistic approach
• Design of a heat exchanger network
• Methodology
• Pinch Analysis
• Heat exchanger network with manual or
  automatically calculation
• Results
• Heat Exchanger Network
• Resulting energy demand curves and energy
  availability curves (kWh/a, temperature levels)

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Step 7.3 Pre-design of heat exchangers network

• Heat integration with a holistic approach
• Placement of the HR module within the audit
  structure
• Prior to new energy supply design
• Possible re-calculation with new supply systems
• Energy streams based on heat/cold generation
  equipment could change
• Result
• Heat Exchanger Network
• Resulting energy demand curves and energy
  availability curves (kWh/a, temperature levels)

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Step 7.3 Pre-design of heat exchangers network

• Criteria for a HEX network
• Use of heat at a certain temperature level for
  heating other streams to a similar temperature
  level
• Power of heat exchange
• Total transferable energy over the heat
  exchangers
• Heat integration within the same process should
  be given priority - direct use of waste heat
• Use of heat that has to be cooled down by a
  cooling machine for heating up processes increase
  the energy savings by the heat exchange, as the
  external energy supply of the heat source and the
  heat sink can be saved
• Distance between the heat source (hot stream) and
  heat sink (cold stream)
• Practical issues, such as fouling factors,
  necessity of indirect heat exchange via a heat
  transfer media, temperature and pressure aspects
  etc.
• Investment costs and saved energy costs

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Step 7.3 Pre-design of heat exchangers network

• Standard values for ?Tmin and the heat transfer
  coefficient a

• Heat exchanger types and overall heat transfer
  coefficients

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Step 7.3 Pre-design of heat exchangers network

• Heat demand and availability curves
• remaining heat demand and availability curves can
  be drawn as a basis for further design of energy
  supply systems
• Yearly load curves are a good basis for the
  design of new supply equipment

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STEP 7.4 Pre-design of alternative supply system

• Applied after process optimization and
• heat recovery
• Objective
• Minimization of the primary energy consumption
  and the environmental impact

• Scope of the measures
• Heat supply equipment changes
• Fuel changes
• Distribution system changes

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STEP 7.4 Pre-design of alternative supply system

• Starting point
• The analysis of the aggregate energy demand
  (statistical breakdown) taking into account
• Temperature level of remaining heat demand
• Quantity of demand and waste heat availability
• Temporal distribution of demand and waste heat
• Space availability
• Availability of alternative energy sources and
  their cost (biomass,)

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STEP 7.4 Pre-design of alternative supply system

• Heat supply cascade suitable equipment selection
  
• Most efficient equipment covers base load and at
  low temperature levels (large number operating
  hours)
• Peak load and at high temperatures is covered by
  appropriate less efficient equipment.

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STEP 7.4 Pre-design of alternative supply system

• Dimensioning of equipment for base load,
  intermediate load and peak load

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STEP 7.4 Pre-design of alternative supply system
Design process steps

• Selection of type of equipment to be used and
  order in the heat cascade
• carried out manually by the auditor or proposed
  by the EINSTEIN tool
• Dimensioning of each type of equipment in the
  cascade
• helped with the EINSTEIN tools design
  assistants
• Selection of the optimum combination of the
  whole
• done essentially by trial-error
• Iterative optimization of the sequence heat
  recovery heat cold supply
• as changes in supply system may lead to changes
  in available waste heat