Ideal ways of maintaining solar industrial heaters to keep maintaining optimum efficiency and performance

1. Good Practices in maintaining
Industrial solar water heaters
R.Sivakumar
21.12.2017

2. Solar Water Heaters are sustainable energy sources for industrial heating solutions,
for applications with temperature requirements from 40 deg C up to 120 deg C.
Solar Thermal Systems can reduce energy costs significantly, as use of fossil fuel can
be reduced in Industrial applications.
Solar Thermal Systems mitigate carbon emission through part replacement of fossil
fuels, contributing to greener Earth.
Investments in Solar Thermal System yield attractive Payback!
Why Solar Water Heaters?

3. Investments in industrial solar thermal system going waste due to
maintenance ?
Is the system currently defunct or under performing ?
Is there return on investment in solar thermal system already installed ?
Are they maintained well?

4. System deliver solar thermal energy during sunshine hours only daily
Systems deliver heat output for 24x7 heat output , where required
temperatures maintained both during day and night using thermal storage
tanks.
System may also incorporate hybrid versions of integrating solar hot water
systems in industrial applications with thermic fluid based heating circuit
fired by boilers.
Inspect and assessment of the system for hot water delivery.
Different Configurations for varied applications

5. Single Series Systems Single Series- Pressurised System

6. Double Series System Four-in -Series System

7. Solar Radiation
Solar heater system performance depends on solar radiation level at the
site.
Every solar module consisting of solar collectors should be free from any
shadow falling on them which can adversely impact the solar absorption
efficiency.

8. Elements of industrial solar hot water system
Solar Collectors (Evacuated tube collectors)
Piping
Strainers
Pumps
Valves
Heat Exchanger
Storage tank
Instrumentation
Controllers

9. General Maintenance
OPERATIONS
ROUTINE MAINTENANCE (DAILY/MONTHLY)
PREVENTIVE MAINTENANCE
(MONTHLY/QUARTERLY)

10. Breakdown Maintenance
FAULT DIAGNOSIS
CORRECTIVE ACTION (REPAIRS)
DOCUMENTATION

11. Solar Evacuated Tube Collectors (ETC)

13. Solar Collector Maintenance
Inspect for water shortage in solar collectors.
Refill water early morning or late evening to avoid ETC breakages.
Check leakage of water from tubes / manifold.
Check outer surface of tube for deposits and clean them periodically .
Replace all broken tubes to ensure full capacity of the plant.

14. ETC tube cleaning process

15. A fully cleaned solar ETC module

16. Broken Tubes in solar collector

17. Damaged ETC tubes sample (Vaccum released)

18. Instrumentation & Calibration
RTD sensors and their calibration status.
Check all pneumatic valves for proper operation.
Check all solenoid valves for proper operations.
RTD PT100 resistance chart

19. Temperatures
Heat Exchanger maintenance (PHE)
Open out and check for the gasket condition
Check for scaling or soiling on the plates.
Carry out descaling operations.
Check for deposits on serpentine coil in the process tank that prevent
effective heat transfer.
Check for water leakage from the coil and arrest the same.

20. Soiling in PHE plates After Cleaning

21. Serpentain coil heat exchanger maintenance

22. Pressure tank maintenance
Check for leakages at flanges (gasket),Pipe joints and check valve actuations.
Circulation pumps and accessories maintenance
Check Y- strainer blockage and clear .
Check pump contactor wire connection.
Check NRV valve for any blockage and clean.
Inspect all pump mounting and supports for rust formation, if required
replace the support.

23. Pipe line maintenance
•Check for pipeline airlocks by opening air valves in the system.
•Check for pipeline leakages as well as at joints.
Inspection of Thermal insulation damages
•Check for pipeline insulation, if any damage rework to correct the same to
ensure any heat loss is avoided.

24. Temperatures
Parameter Unit Specifications
Colour Colourless
Odour Unobjectionable
Turbidity NTU 5
pH 6.5 to 8.5
Total Dissolved Solids Mg/L 50
Total Alkalinity Mg/L 20
Total Hardness Mg/L 30
Calcium Mg/L 7.5
Magnesium Mg/L 3
Chloride Mg/L 25
Sulphate Mg/L 20
Iron Mg/L 0.003
Nitrate Mg/L 4.5
Fluoride Mg/L 1
Desired water quality for industrial solar water heaters

25. Water Leakages at ETC & Manifold joints
Observe for any leakages at tube and module level
Check for silicon washer quality, If damaged, replace
Continuous leak from manifold could be indication of severe rusting inside
manifold joints
All rusted manifolds need urgent replacement
Leaking tubes could cost heavy in terms of down time of the system

27. Precaution to be taken for peak summer months
Solar radiation levels peak from February to June
A well designed system shall deliver required heat output ideally both during peak
summer and during winter/monsoon months.
It is a good practice to avoid excess heating of modules by shutting down certain no.
of modules of the system for normalization.

28. System Controller with remote monitoring option
Solar Hot water System is controlled through PLC based or microprocessor based
system
All operational parameters data acquired through different sensors and logged at
sampling intervals and displayed on screen at site
The data can be exported for online monitoring and analysis through RF modem
The analysis facilitates spotting trends in the performance of the system for various
parameters for different times

29. Personal Protection Equipments
Approvals needed from concerned Authority
Height work
Hot work
Electrical work
Safety norms during Maintenance

31. Safety Belt worn by Technician safely secured with Safety rope while on roof

32. Assuredheat can create value for non functional Industrial Hot Water Systems
Assuredheat is the services division Aspiration Energy, the pioneers for
sustainable Industrial heating applications using solar energy, in India
We are committed to our slogan “ Fast Forward to the Solar Future” and will
offer a complete revamp / repairs for such systems, that can potentially unlock
the sunk capital on these water heater systems.
We bring in the best of practices in maintainence!
How can Assuredheat help?

33. Contact:
Assuredheat
7, II Trust Link Road
Mandaveli
Chennai-600028
Ph: 044 - 4218 5301
E mail: r.sivakumar@assuredheat.com
THANK YOU