A Design Tool for Thermosyphon Solar Water Heaters using TRNSYS and Genetic Algorithms

1
International Conference on Energy Technologies
and Policy

• A Design Tool for Thermosyphon Solar Water
  Heaters using TRNSYS and Genetic Algorithms

M J R Abdunnabi, D L Loveday and J A Wright
Civil and Building Engineering Department,
Loughborough University, UK
2
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms

• Thermosyphon systems

Pump-free devices used to provide households with
hot water for domestic purpose

• Can be found in different configurations
• - the system under consideration

• Flat plate collector (fin and tube)
• Insulated storage tank (horizontal vertical)

3
The main aim
Design Tool for Thermosyphon Solar Water Heaters
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Thermal performance of the system
Optimisation Method
Genetic Algorithms
TRNSYS Programme
4
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Evaluating the thermal performance of TSWHs
TRNSYS component Type 45
Experimentally-determined information
Type 210
Type 211
Collector characteristics component
Pipe-Tank heat losses component
Modelling Validation
5
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms

• Incorporating New Components in TRNSYS

Parameters
Type 211
Type 210
Type 45
Outputs
Inputs
Type 245
6
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms

• Original and Modified TRNSYS Models

• Original TRNSYS Model (OM)

• Modified TRNSYS Model (MM)

7
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms

• Modified TRNSYS Model Validation

,
,

• Two thermosyphon systems data were used for
  the validation

8
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms

• Modified TRNSYS Model Validation System 1

Yearly average error lt 3.45
4.87
Monthly solar fraction of system1
9
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms

• Modified TRNSYS Model Validation System 2

Yearly average error lt 4.17
6.06
Monthly solar fraction of system2
10
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Design Tool for Thermosyphon Solar Water Heaters
Thermal performance of the system
Optimisation Method
Genetic Algorithms
TRNSYS Programme
11
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Optimisation

• Problem Formulation

(Constrained single optimisation problem)
Subject to
Where is the vector
the of n design variables
12
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Optimisation

• Design variable of thermosyphon system

13
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Optimisation
Method of Solution

• Genetic Algorithm

• Binary encoding
• Tournament selection
• Uniform crossover with rate of 0.3

Constraint handled by using Stochastic Ranking
procedure
14
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Design Tool

• Running the Design Tool

Modified TRNSYS Model and Optimisation Programme
can be linked as shown below

• Requirement

Fortran Programme

• Weather data
• Load pattern and volume
• Material properties and prices

15
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Case Study (Tripoli, Libya and Birmingham, UK)

• The optimum system design
• 180 litres of daily hot water
• at a temperature of 60 ºC
• for different solar fraction values

• Load Pattern

16
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Case Study

• solar system material and its prices

17
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Case Study
Optical and thermal properties of the cover and
the absorber
Thermal properties of the material
18
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Case Study
For a system with 3.87 m2
79.2


27.7
19
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
(Tripoli - Libya)
Case Study

• Optimum System design

Tuser 60.0 ºC


20
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Case Study (Tripoli - Libya)

• Optimum System design

21
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Case Study (Tripoli - Libya)

• Optimum System design

22
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Case Study (Birmingham, UK)

• Optimum System design

23
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Case Study (Birmingham, UK)

• Optimum System design

24
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms

• Conclusions

• Adding new components to TRNSYS to simulate
  the performance and to optimise the design
  parameters of thermosyphon system gives
  acceptable predictions

• Modified TRNSYS model enhances flexibility by
  offering the ability to vary collector and tank
  design parameters

• The design tool can be used to generate bespoke,
  optimised designs of thermosyphon solar water
  heating systems for individual geographic
  locations worldwide.

• The example optimised designs for Tripoli and
  Birmingham are based on only a limited number of
  variables improved performances (improved
  optima) might be achieved if additional factors
  are accounted for (e.g. collector orientation)

25
A Design Tool for Thermosyphon Solar Water
Heaters using TRNSYS and Genetic Algorithms
Thanks for your Listening any Questions?