R.S. Adhikari

Conventional hybrid photovoltaic/thermal (PV/T) air heating collectors: steady-state simulation

This investigation is concerned with the performance analysis of a conventional hybrid photovoltaic/thermal air heating collector. A simulation model is developed and various performance parameters are calculated for single-glass and double-glass configurations. Results are presented to show the effect of various design and operational parameters on the performance of a system. These results are useful for designing such systems more scientifically. However, final selection of design and operational variables must be based on the cost-effectiveness of the system.

Performance analysis of a hybrid photovoltaic/thermal (PV/T) collector with integrated CPC troughs

In the present investigation a theoretical analysis has been presented for the modelling of thermal and electrical processes of a hybrid PV/T air heating collector coupled with a compound parabolic concentrator (CPC). In this design, several CPC troughs are combined in a single PV/T collector panel. The absorber of the hybrid PV/T collector under investigation consists of an array of solar cells for generation of electricity, while collector fluid circulating past the absorber provides useful thermal energy as in a conventional flat plate collector. In the analysis, it is assumed that solar cell efficiency can be represented by a linear decreasing function of its temperature. Energy balance equations have been developed for the various components of the system. Based on the developed analysis, both thermal and electrical performance of the system as a function of system design parameters are presented and discussed. Results have been presented to compare the performance of hybrid PV/T collector coupled with and without CPC. Copyright

Simulation studies on a multi-stage stacked tray solar still

Abstract In this paper, a computer simulation model is presented for studying the steady-state performance of a multi-stage stacked tray solar still. The model is validated by the results of simulated experiments on a three-stage unit having an immersion type electric heater as the heating source. The results obtained from the model using the modified heat and mass transfer relationships proposed in previous study are in good agreement with the experiments. Numerical results are also presented in the paper to appreciate the relative performance of the proposed multi-stage, stacked tray solar still with a diffusion type, multi-stage solar still.

System performance studies on a photovoltaic/thermal (PV/T) air heating collector

A computer simulation model is presented for the analysis of a solar photovoltaic/thermal (PV/T) hybrid collector with air as heat transfer fluid and algorithm for making quantitative prediction regarding the performance of the system is described. Thermal efficiency curves for the solar PV/T hybrid collectors corresponding to various type of absorbers have been derived. In order to appreciate the model, numerical calculations have been made for evaluating the system performance corresponding to typical climate of Delhi, India

Experimental design and computer simulation of multi-effect humidification (MEH)-dehumidification solar distillation

In this paper, the experimental design and computer simulation model of a multi-effect humidification/dehumidification (MEH) solar desalination system has been presented. The pilot plant on MEH was designed, fabricated and tested at the Center for Energy Studies, Indian Institute of Technology Delhi, India. The heat collection part has been designed to provide continuously the hot water to the distillation unit. The distillation chamber consists of humidifier and dehumidifier towers. The circulation of air in the two towers is being maintained by natural convection. The system modeling is based on various heat and mass transfer equations and their numerical solutions. The developed model is useful in the estimation of the distillation plant output and optimized various components of the system viz. solar water heater, humidification chamber, and condensation chamber.

Transient simulation of conventional hybrid photovoltaic/thermal (PV/T) air heating collectors

In the present investigation, the authors have developed a computer simulation model for predicting the transient performance of a conventional photovoltaic/thermal (PV/T) air heating collector with single- and double-glass configurations. In order to appreciate the model, numerical calculations have been made to evaluate the system performance corresponding to typical climate of Delhi, India. It has been observed that the hybrid PV/T systems are interesting in respect to system efficiencies, however, their adaptability in future must be weighed in terms of cost effectiveness of these systems.

Thermal performance of a solar pressure cooker based on evacuated tube solar collector

This paper presents the thermal performance of a community type solar pressure cooker based on evacuated tube solar collector. The developed design of solar pressure cooker has separate parts for energy collection and cooking unit and both are coupled by heat exchanger. The paper has presented the performance results of experimental study conducted on solar pressure cooker and a simulation model has been developed for predicting the cooker performance under a variety of operating and climatic conditions. The theoretical model is validated against the experimental results. The obtained results have suggested a possibility of several batches of solar cooking on a clear sunny day under typical conditions of Delhi.

Performance evaluation of a single solar air heater with N‐subcollectors connected in different combinations

In the present communication, a generalized procedure has been described for the performance evaluation of a solar air heater with N-subcollectors with identical collector aspect ratio connected in various combinations such as in series, parallel and series–parallel. It has been found that the performance of a solar air heating system can be improved by operating several subcollectors in series in place of a single large collector with the same total area. Results have been presented to show the effect of various design parameters, viz. collector aspect ratio, mass flow rate, etc. on the performance of solar air heater with N-subcollectors in series, parallel and series–parallel combinations. Copyright

Techno-economic analysis of a multi-stage stacked tray (MSST) solar still

Abstract A techno-economic analysis of multi-stage stacked tray (MSST) solar still coupled with a solar collector through a heat exchanger has been developed. Various heat and mass transfer phenomena have been considered for evaluating its distillate output. The economic analysis takes into account capital and maintenance costs, and life of the system and estimates the cost of unit mass of distilled water ( C u ). In order to appreciate the developed model, numerical calculations have been made to optimize different design parameters, namely number of stages, evaporation surface area and collector area corresponding to climate of Delhi, India. The effect of useful life of the distillation unit on the cost of unit mass of distilled water has also been discussed. The study also includes a discussion on the sensitivity of cost of unit mass of distilled water in reference to the useful life of distillation chamber, cost of solar collector and other associated parameters.

Solar photovoltaic and thermal systems for electricity generation, space heating and domestic hot water in a residential building

In this paper a techno-economical analysis has been carried out for the solar energy technologies (PV and thermal) and GSHP system employed for energy supply in a residential building for different end uses e.g. heating, hot water and electricity. The building is a three-story located in Milan, Italy. The building was designed based on current regulations on energy efficiency in buildings. The HVAC system is designed for minimising energy consumption by the appropriate choice of the heating and cooling systems. The space heating energy is supplied by a GSHP system with vertical ground heat exchangers. The domestic hot water is produced by a solar thermal system. A major part of electricity required for lighting, domestic appliances and the functioning of GSHP system is generated through a PV system. Both the solar thermal and PV systems are installed on the building roof.