Solar energy connected with paddle dryer

1. TAHA 塔哈Presented by:
Solar energy

2. Renewable energy
Renewable energy is generally defined as energy that is
collected from resources which are naturally replenished on a
human timescale, such as sunlight, wind, rain, tides, waves, and
geothermal heat.
Renewable energy often provides energy in four important
areas: electricity generation, air and water heating/cooling,
transportation, and rural (off-grid) energy services.

3. Introduction
Based on REN21's(1) 2016 report, renewables contributed
19.2% to humans' global energy consumption and 23.7%
to their generation of electricity in 2014 and 2015,
respectively. This energy consumption is divided as 8.9%
coming from traditional biomass, 4.2% as heat energy
(modern biomass, geothermal and solar heat), 3.9% hydro
electricity and 2.2% is electricity from wind, solar,
geothermal, and biomass.
1. REN21, the Renewable Energy Policy Network for the 21st Century, is a global renewable energy multi-
stakeholder policy network that provides international leadership for the rapid transition to renewable
energy

4. Introduction
 Renewable energy resources exist over wide geographical
areas, in contrast to other energy sources, which are
concentrated in a limited number of countries. Rapid
deployment of renewable energy and energy efficiency is
resulting in significant energy security, climate change
mitigation, and economic benefits.
 While many renewable energy projects are large-scale,
renewable technologies are also suited to rural and remote
areas and developing countries, where energy is often crucial
in human development.

5. Types or renewable energy
 Biomass energy
 Wind energy
 Hydro energy
 Geothermal energy
 Solar energy

6. Bio energy

7. Wind power

8. Hydropower

9. Geothermal energy

10. Solar energy

11. Solar energy

12. Introduction to solar energy
Solar energy is radiant light and heat from the Sun that is harnessed using a
range of ever-evolving technologies such as solar heating, photovoltaic,
solar thermal energy, solar architecture and artificial photosynthesis(1).
It is an important source of renewable energy and its technologies are
broadly characterized as either passive solar or active solar depending on
how they capture and distribute solar energy or convert it into solar power.
 Active solar techniques include the use of photovoltaic systems,
concentrated solar power and solar water heating to harness the energy.
 Passive solar techniques(2) include orienting a building to the Sun,
selecting materials with favorable thermal mass or light-dispersing
properties, and designing spaces that naturally circulate air.
(1)Artificial photosynthesis is a chemical process that replicates the natural process of
photosynthesis, a process that converts sunlight, water, and carbon dioxide into
carbohydrates and oxygen.
(2)This is called passive solar design because, unlike active solar heating systems, it does not
involve the use of mechanical and electrical devices

13.  No pollution
 Inexhaustible
 Contribution to energy supply and CO2 reduction
 The annual collector yield of the world was 109,713 GWh
(394,968 TJ). This corresponds to an oil equivalent of 12.4
million tons and an annual avoidance of 39.4 million tons
of CO2.
 The annual collector yield of Taiwan was 918 GWh (3306
TJ). This corresponds to an oil equivalent of 101,780 tons
and an annual avoidance of 322,393 tons of CO2.
Advantages of using Solar Energy
Weiss, Werner, I. Bergmann, and G. Faninger. Solar Heat Worldwide–Markets and Contribution to the Energy
Supply 2008. International Energy Agency, 2010.

14. Earth’s energy budget

15. Solar spectrum
In the solar
applications they
concerned primarily
with radiation in a
wavelength range of
0.25 to 3.0 µm, the
portion of the
electro-magnetic
radiation that
includes most of the
energy radiated by
the Sun.

16. FUNDAMENTAL CONCEPTS
We know that radiation originates due to emission by matter and that its
subsequent transport does not require the presence of any matter.
But what is the nature of this transport?
One theory views radiation as the propagation of electromagnetic waves.
The complete
electromagnetic
spectrum is
delineated in
this Figure.

17. FUNDAMENTAL CONCEPTS
Where h is Planck’s constant (h=6.6256 × 10^34 J s).
It follows that as the frequency ʋ increases (i.e., as the
wavelength decreases), the photon energy increases.
c= light speed (3*10^8m/s), λ= wave length

18. FUNDAMENTAL CONCEPTS
Short wave length
Higher energy
Increasing
temperature

19. SPECTRAL DISTRIBUTION OF
EXTRATERRESTRIAL RADIATION
In addition to the total energy in the solar spectrum , it is useful to know the
spectral distribution of the extraterrestrial radiation. That is, the radiation that
would be received in the absence of the atmosphere.
• A standard spectral
irradiance curve has
been compiled based
on high-altitude and
space measurements.
• The WRC(WRC:
World Radiation
Center) standard
is shown in this
Figure.

20.  Photovoltaic (PV)
 Solar cell
 Solar thermal energy
 Solar water heater
 Solar thermal power
 Solar cooling
 Solar thermal ventilation
Types of Applications of solar energy

21. Introduction to Photovoltaic
 What is photovoltaic
 Solar cell

22. What is Photovoltaic
 A method of generating electrical power by converting solar
radiation into direct current electricity through some materials
(such as semiconductors) that exhibit the photovoltaic effect.

23. Solar Cell
 Sun light of certain wavelengths is
able to ionize the atoms in the
silicon.
 The internal field produced by the
junction separates some of the
positive charges ("holes") from the
negative charges (electrons).
 If a circuit is made, power can be
produced from the cells under
illumination, since the free
electrons have to pass through the
junction to recombine with the
positive holes.

24. Worldwide growth of
photovoltaic

25. Solar Thermal Energy Systems
 How to use solar thermal energy
 Types of solar collectors
 Solar water heater
 Solar thermal power

26. How to Use Solar Thermal Energy
working fluid
thermal energy
Solar Radiation Solar Thermal Energy
Solar collector
Working fluid

27. Types of Solar Collectors
 Collectors and working temperature
Low temperature
Medium
temperature
High temperature

28. Flat-plate collector
Use both beam and diffuse solar radiation, do not
require tracking of the sun, and are low-maintenance,
inexpensive and mechanically simple.

29. Flat-plate collector

30. Flat-plate collector
 Glazed collector  Unglazed collector

31. Flat-plate collector

32. Flat-plate collector
Main losses of a basic flat-plate collector during
angular operation
Weiss, Werner, and Matthias Rommel. Process Heat Collectors. Vol. 33, 2008.

33. Evacuated tube collector
 A collector consists of a row of parallel glass tubes.
 A vacuum inside every single tube extremely reduces
conduction losses and eliminates convection losses.

34. Evacuated tube collector
Heat pipe

35. Collector efficiency
http://polarsolar.com/blog/?p=171

36. Parabolic trough collector
 Consist of parallel rows of
mirrors (reflectors) curved in
one dimension to focus the
sun’s rays.
 In the concentrating type the
radiation is reflected to an
element with high solar
radiation. Therefore, we can
get higher temperature for this
type as compared to flat plate
collector.

37. Solar-Trough-Grid-Application

38. linear Fresnel receiver

39. Heliostat field collector
 A heliostat is a device that
includes a plane mirror
which turns so as to keep
reflecting sunlight toward a
predetermined target.
 Heliostat field use hundreds
or thousands of small
reflectors to concentrate the
sun’s rays on a central
receiver placed atop a fixed
tower.

40. Solar Thermal Power
 Conversion of sunlight into electricity
 Direct means : photovoltaics (PV),
 Indirect means : concentrated solar power (CSP).
 High temperature applications
by means of sun-tracking, concentrated solar collectors)
Solar thermal power

41. Solar Thermal Power
Types of solar thermal power plant
Technology roadmap concentrating solar power, IEA, 2010.

42. Solar Thermal Power
Combination of storage and hybridization in a solar
thermal plant

43. Solar Thermal Power
PS10 and PS20 solar power tower (HFC)
(Seville, Spain). 2007 and 2009

44. Solar Thermal Power
Kimberlina solar thermal energy plant (LFR)
(Bakersfield, CA), 2008.

45. Solar Thermal Power
Calasparra solar power plant (LFR)
(Murcia, Spain) 2009.

46. Solar Thermal Power
Andasol solar power station (PTC)
(Granada, Spain), 2009
Puertollano solar power station (PTC)
(Ciudad real, Spain), 2009

47. Solar desalination/distillation
 Solar humidification-dehumidification (HDH)
 HDH is based on evaporation of brackish water and consecutive
condensation of the generated humid air, mostly at ambient pressure.
 The simplest configuration: the solar still.
 In sophisticated systems, waste heat is minimized by collecting the heat
from the condensing water vapor and pre-heating the incoming water
source.

48. Solar Thermal Applications

49. Restrictions in Using Solar Energy
 Geographical aspects
 Financial aspects

50. Geographical Aspects
 Low energy density
 Solar radiation has a low energy density relative to other
common energy sources
 Unstable energy supply
 Solar Energy supply is restricted by time and
geographical location
 Easily influenced by weather condition

51. Financial Aspects
 Higher cost compared with traditional energy
 The capital cost in utilization of solar energy is generally
higher than that of traditional ones, especially for PV.
 Solar water heater
 Most economically competitive technology by now.
 The need of SWH is inversely proportional to local
insolation.

52. My research area

53. My research area
 Outlook of my Master thesis.
 The CSE assisted paddle dryer system:-
 Introduction
 The Paddle dryer.
 The scheme of CSE assisted paddle dryer system.
 The system description.

54. Outlook Of My Master Thesis
1. I will develop a calculating model to design a (drying,
heating) system depending on the parameters of an offered
industrial application in Nanjing, China or in my country .
2. Design the solar system:
 Parabolic trough collector, or
 Heliostat field collector,
depending on the typical solar radiation conditions in Nanjing,
China or in my country.

55. Introduction
Paddle dryer is one kind of indirect dryers that has been widely used in
removing moisture of many materials , such as sewage sludge , brown coal etc.
When paddle dryer is used in drying low-valued materials, drying energy
consumption becomes the critical issue that determines whether the drying
project is economically feasible
or not.

56. Introduction
 There are many ways to reduce drying energy consumption. Solar drying
technology is one of them.
 Solar drying can provide full or part of the drying energy consumption
required by the paddle dryer.
 In Ref.[4] a solar-energy assisted Paddle dryer for sewage sludge drying
with flat-plate collectors was developed. The operating temperature is in
the range 60℃~80℃. But in many applications, the appropriate operating
temperature of working fluids (e.g., vapor or heat conducting oil) that
paddle dryers need ranges from 100℃ to 200℃. In this case concentrated
solar energy (CSE) device with trough-type collectors is a suitable choice
to assist drying process.
 In some industrial applications rather than removing moisture of the
materials, there are many industrial applications require higher temperature
300℃~450℃, in that cases we can’t use trough-type collectors , but we
have another solar systems such as Heliostat field collector HFC , which
can provide this range of require temperature.

57. 1- Motor 2- Hollow shaft 3- Hollow paddle 4- Shell
Fig. 1 Scheme of paddle dryer
Paddle dryer

58. Scheme of CSE assisted paddle dryer system
1- Paddle dryer 2- Thermal storage tank 3- Pump 4- Heater 5- CSE 6- Control valve
Fig. 2 Scheme of CSE assisted paddle dryer system

59. System description
Figure 1 shows the scheme of the twin-shaft type paddle dryer with 3m2
nominal heat transfer area which is found in our lab. When the two shafts
rotate conversely, the wet material (e.g., sewage sludge, brown coal) in the
dryer is agitated and pushed forward, i.e. flowing from left to right in Fig.1.
When hot working fluid (heat conducting oil in this paper) flows through the
hollow shafts and paddles, the wet material is heated indirectly and moisture
is then removed. Conventionally, the heat (Q) needed by the paddle dryer is
supplied by burning fuels (e.g., coal, biomass) or electricity (through Heater
in Fig. 2).
Figure 2 shows the scheme of CSE device assisted drying system. At night or
when sunlight is insufficient the CSE device does not provide heat to drying
process. When solar radiation is strong, the CSE device takes effect. Starting
from the thermal storage tank, the working fluid flows to the heater to provide
heat . When the working fluid is heated to the operating temperature T, it
enters into the paddle dryer to heat wet material and remove its moisture.

60. Paddle dryer and concentrated solar energy
device
(a) Paddle dryer (b) Concentrated solar energy
device

61. Illustration Video

62. References
1. John A. Duffie (Deceased),Emeritus Professor of Chemical
Engineering, William A. Beckman, Emeritus Professor of Mechanical
Engineering: Solar Engineering of Thermal Processes, Fourth Edition,,
Solar Energy Laboratory, University of Wisconsin-Madison.
2. Jiangyong Dua, Xinzhi Liub, Houlei Zhangc, Design and Analysis
of Concentrated Solar-energy Assisted Paddle Dryers, School
of Energy and Power Engineering, Nanjing University of Science and
Technology, Nanjing 210094, Jiangsu, China.
3. Franz Mauthner, Werner Weiss, Monika Spörk-Dür ,Solar Heat
Worldwide Markets and Contribution to the Energy Supply 2013,E D I T
I O N 2 0 1 5 AEE INTEC ,AEE - Institute for Sustainable
TechnologiesA-8200 Gleisdorf, Austria.
4. X. Zhu: Study on Sewage Sludge Drying in Paddle Dryer with Solar
Assisted (in Chinese)(Zhejiang University, China 2008).