Experimental study of an innovative glazed solar air collector tested in real conditions

Nowadays, the building sector has a great impact on the CO2 emissions worldwide being responsible for more than a third of energy consumptions. In order to reduce their impact on the environment it is mandatory to implement renewable energy sources (RES) to produce the so called “green energy”. One of the main disadvantages of the systems using RES is the discontinuity in operation and one of the most used RES is the solar radiation which is implemented worldwide and has a great potential to be successfully used. Among the solar systems, solar air collectors (SAC) are systems easy to implement and with low operating costs. For enhancing the overall efficiency of a SAC and to increase the number of hours of operation it is imperative to use thermal energy storage materials (TES). The aim of this paper is to experimentally analyse the implementation of latent heat storage materials (phase changing materials – PCM) in glazed solar air collectors and for this purpose two similar collectors were studied in real conditions. After several experimental analysis conducted we have observed that during the night the PCM slowly releases the energy embodied during the daytime and the rise in temperature is higher in 57% of the time in this case. Moreover the amplitude of outlet temperature variation is lower with 34% in case of using PCMs

Numerical investigation on combustion and NO

Cogeneration groups equipped with gas turbines usually operate with natural gas. The new requirements regarding the flexibility of functioning both with conventional and alternative fuels have led to the development of new solutions. An afterburning installation facilities, on the one hand, the combustion of fuels which can not normally be used in gas turbines, and on the other hand, allows a rapid adaptation of the cogeneration group to the user's variable thermal energy requirements. In some cases, an afterburning installation may contribute to the reduction of NOx emissions. It also increases the group's adaptability to changing environmental conditions, especially during the summer. Having in mind these tendencies and starting from the data collected from the 2xST 18 – Suplacu de Barcau cogeneration plant, this paper presents a numerical analysis of an afterburner in order to switch from natural gas to natural gas / kerosene functioning, with minimal modifications to the existing solution. A 3D steady RANS numerical integration of the Navier-Stokes equations has been carried out using the commercial software ANSYS CFX. For future research work, it will be taken into consideration the use of more complex reaction mechanisms and the variation of the spray angle will be considered. Also, in order to validate the CFD results a combustion experiments campaign will be conducted

Experimental study of an innovative glazed solar air collector tested in real conditions

Nowadays, the building sector has a great impact on the CO2 emissions worldwide being responsible for more than a third of energy consumptions. In order to reduce their impact on the environment it is mandatory to implement renewable energy sources (RES) to produce the so called “green energy”. One of the main disadvantages of the systems using RES is the discontinuity in operation and one of the most used RES is the solar radiation which is implemented worldwide and has a great potential to be successfully used. Among the solar systems, solar air collectors (SAC) are systems easy to implement and with low operating costs. For enhancing the overall efficiency of a SAC and to increase the number of hours of operation it is imperative to use thermal energy storage materials (TES). The aim of this paper is to experimentally analyse the implementation of latent heat storage materials (phase changing materials – PCM) in glazed solar air collectors and for this purpose two similar collectors were studied in real conditions. After several experimental analysis conducted we have observed that during the night the PCM slowly releases the energy embodied during the daytime and the rise in temperature is higher in 57% of the time in this case. Moreover the amplitude of outlet temperature variation is lower with 34% in case of using PCMs