Effect of parallel and series connection
- 1. EFFECT OF PARALLEL AND SERIES CONNECTION CONFIGURATION OF SOLAR COLLECTOR ON THE SOLAR SYSTEM PERFORMANCES PREPARED BY SAMMY JAMAR CHEMENGICH
- 2. INTRODUCTION
- 3. ABSTRACT • This report highlights the domestic water heating system transient behavior in order to bring out the effect of the series or parallel connection of a set of flat plate solar collectors on the performances of the solar system. • The installation of solar collectors either in series or parallel connection perform at different levels of efficiency. • We observe how the series and parallel connection of a flat plate collector set affect the solar system thermal performances and how they affect also the pressure losses simultaneously.
- 4. MATHEMATICAL MODELLING OF THE SYSTEM We consider the following calculations and formulas; We use MATLAB as the design software We calculate heat balances; Heat balance at the transparent cover Heat balance of the confined air between the absorber and the cover Heat balance at the absorber plate Heat balance for the working fluid Heat balance at the storage tank Pressure drop calculation
- 5. PROGRAM DEVELOPMENT • Based on different differential equations and the heat transfer coefficients, a MATLAB program is developed, using as input data, the thermo-physic and geometric properties of the collector elements, those of the storage tank, the hydraulic geometry and its configuration in terms of obstacle constituent, characterized by their specific singular pressure drop coefficients. • The measured direct normal, horizontal diffuse and global solar irradiation as well as the ambient temperature and wind speed are also used.
- 6. PRESENTATION OF RESULTS AND DISCUSSION 1. PRESSURE DROP IN THE COLLECTORS
- 7. CONT.. • It is observed that the pressure drop in hydraulic circuit of the collector increases according to a parabolic form. This is linked to the fact that the linear and single pressure drop equations are proportional to the square values of the fluid velocity. • It is observed also that if the fluid temperature increases the total pressure drop decreases. This is linked to the fact that that increasing the water temperature leads to decrease in its density and consequently the pressure drop decreases also.
- 8. EFFECT OF THE SERIES AND PARALLEL ARRANGEMENT ON THE SOLAR SYSTEM PERFORMANCES 1. Mean fluid temperature evolution (parallel connection)
- 9. (B) Mean Fluid Temperature Evolution (Series Connection)
- 10. CONT.. • From results presented in the figures above, it is observed that for a constant storage volume, increasing the collector area leads to increase in the temperature of the fluid. • It is observed also that for the same collecting surface where collectors are connected in series configuration, the outlet fluid temperature from the panel is higher than that obtained for the case of parallel configuration. • In series connection mode, the temperature of solar panel increases and consequently the heating losses from the system to the surrounding environment increases and remain higher than that which would be lost
- 11. HEAT POWER LOSS FROM THE SOLAR HEATING SYSTEM (PARALLEL CONNECTION)
- 12. HEAT POWER LOSS FROM THE SOLAR HEATING SYSTEM (SERIES CONNECTION)
- 13. INSTANTANEOUS EFFICIENCY OF SOLAR SYSTEMS (PARALLEL CONNECTION)
- 14. INSTANTANEOUS EFFICIENCY OF SOLAR SYSTEMS (SERIES CONNECTION)
- 15. CONT.. • The collector temperature increases, the heat losses power increases and consequently its instantaneous efficiency decreases as shown in the above slides.
- 16. EFFECT OF PARALLEL OR SERIES CONNECTION ON PRESSURE DROP 1. Pressure drop in the hydraulic circuit of the solar systems (parallel connection)
- 17. PRESSURE DROP IN THE HYDRAULIC CIRCUIT OF THE SOLAR SYSTEMS (SERIES CONNECTION)
- 18. CONT.. • From the results presented in figures above it is observed clearly that increasing the number of collectors leads to increase in the pressure drop in the hydraulic circuit. • On the other hand, for the same number of solar collectors it is observed that pressure drop obtained for the case of 2, 3 and 4 collectors connected in series it is about ten times to that obtained for the parallel configuration
- 19. CONCLUSION • From the obtained results we can conclude that connecting a set of collectors in series leads to increasing the outlet solar panel fluid temperature and also leads to decrease the solar collector efficiency and also increase the pressure drop in the hydraulic circuit of the system which in turn leads to increase the pump power consumption. • By contrast connecting collectors in parallel avoids the pressure from increasing in the hydraulic circuit and avoids decreasing the collector’s efficiency and the output temperature level through the panel remains relatively lower. Hence, for solar water heating system choice of the connecting configuration depends from the user need in term of temperature level. • We conclude that the parallel configuration offers a higher efficiency and