Modelling and experimental study of latent heat thermal energy storage with encapsulated PCMs for solar thermal applications

Effects of PCM arrangement and natural convection on charging and discharging performance of shell-and-tube LHS unit

This paper presents the effectiveness of finned multi-tube latent heat thermal energy storage system (LHTES) for medium temperature (∼200 °C) solar thermal power plant in reducing the fluctuations in heat transfer fluid (HTF) temperature caused due to the intermittent solar radiation. Commercially available phase change material (PCM) of melting temperature 168.7 °C is used as the storage material in the shell of LHTES, whereas a thermic oil based HTF passes through the tubes. Majority of the available PCMs have very low thermal conductivity (∼0.2–0.5 W/m.K), which drastically affects the thermal performance of the thermal storage system. Hence, in this study, thermal conductivity enhancer (TCE) in the form of fin is used to enhance heat transfer in the PCM. The fluid flow and heat transfer behaviour latent heat thermal energy storage system in the LHTES is studied by using a numerical model coupled with the enthalpy technique to account for the phase change process in the PCM. The developed numerical model, which is validated with the lab-scale experimental setup, is used to investigate the effect of number of fin, fin thickness and fin height on the HTF temperature at the outlet of the storage system. It is found that the number of fins and fin thickness significantly affect the thermal performance of the storage system, whereas the enhancement in heat transfer for high thermal conductivity material fin is marginal. Further, optimization of LHTES is performed for a defined objective function to identify the best configuration.

Estimation of thermal performance and design optimization of finned multitube latent heat thermal energy storage

Dynamic modelling of ORC-based solar thermal power plant integrated with multitube shell and tube latent heat thermal storage system

An experimental investigation on the thermal performance of vertical multitube shell and tube based latent heat thermal energy storage system (LHTES) during discharging process for solar applications at medium temperature (∼200 °C) is presented in this paper. A commercially available organic phase change material (PCM), A164 having melting temperature of 168.7 °C is stored in the shell side and a thermic oil, Hytherm 600 as heat transfer fluid (HTF), is flown through seven tubes. The effects of three operating parameters, such as inlet HTF temperature, mass flow rate and initial PCM temperature on the outlet HTF temperature are investigated during discharging period. The total energy released, discharging efficiency and heat fraction are analyzed to understand the solidification process of PCM in the multitube LHTES. Thermal Performance Index (TPI) is calculated to evaluate the overall thermal performance of the LHTES under different conditions. The results indicate that the energy released and discharging efficiency increase with increasing mass flow rate and initial PCM temperature and with decreasing inlet HTF temperature. The maximum discharge efficiency and TPI is obtained for the initial PCM temperature of 210 °C with the inlet HTF temperature of 100 °C and the mass flow rate of 0.097 kg/s in this study. Heat fraction is found to be maximum for high mass flow rate, low inlet HTF temperature and higher initial PCM temperature.

Experimental study on discharging performance of vertical multitube shell and tube latent heat thermal energy storage

Heat Transfer Characterization and Optimization of Latent Heat Thermal Storage System Using Fins for Medium Temperature Solar Applications

The instant disclosure provides a composition for fluid catalytic cracking of petroleum based feedstock into useful short chain olefins. The composition comprising: 76-86% of a non-zeolitic material; and 2-30% of at least one zeolite material, the percentage being based on weight of the catalyst composition, wherein one of the zeolites has been modified with 0.1-2.5 wt % metal. The said catalyst was found to be selective in enhancing the usable propylene gas content, while reducing the undesirable dry gas content of the cracked olefinic products. The present disclosure also provides a process for the preparation of the composition. The present disclosure also provides an apparatus (100) and process (200) for fluid catalytic cracking to obtain light olefins. The apparatus comprises a second riser (33) that includes a lower dense riser (2) and upper dilute riser (3). Further, the lower dense riser (2) has a diameter that is 1.1 to 2 times that of the upper dilute riser (3).

Fluid catalytic cracking (fcc) process and apparatus for production of light olefins

The present subject matter relates to a riser, an apparatus, and a process for production of petrochemical feedstock from crude oil. The riser (150) comprises a catalyst inlet (214), a plurality of channels (210), and a channel inlet disposed on each of the plurality of channels (210). One crude oil fraction is fed into one channel (210) and the plurality of channels (210) is to crack the crude oil fractions. Each of the plurality of channels (210) has a different length or diameter based on the crude oil fraction to be cracked.

Production of petrochemical feedstock from crude oil

The present disclosure relates to dual functional FCC catalyst additive. The dual functional catalyst additive is represented by a formula (CuO)A(TiO)B(FeO)C(M1O)D(P2O5)E(SiO2)K(Al2O3)(100-X-K). The dual functional FCC catalyst additive of the present disclosure when used in combination with FCC catalyst, for cracking heavy hydrocarbon feed is capable of providing cracked hydrocarbons with increased propylene yield and reduced olefin content.

A dual functional fcc catalyst additive

The present disclosure discloses a catalyst composition comprising: (a) at least one steamed biochar; and (b) at least one tri-metallic catalyst, comprising metals selected from the group consisting of nickel, copper, zinc, and combinations thereof, wherein nickel loading is in the range of 20-60 wt %, the copper loading is in the range of 0.5 – 5.0 wt %, and the zinc loading is in the range of 0.5 – 5.0 wt % with respect to the at least one steamed biochar. The instant disclosure further relates to a process of preparation of the catalyst composition and a process for production of hydrogen gas and carbon nanotubes.

Kumar Pramod

Papers

Heat Transfer Characterization and Optimization of Latent Heat Thermal Storage System Using Fins for Medium Temperature Solar Applications

Fluid catalytic cracking (fcc) process and apparatus for production of light olefins

Production of petrochemical feedstock from crude oil

A dual functional fcc catalyst additive

A catalyst composition and its applications thereof