scholarly journals Residential Air Conditioning System Integrated with Packed Bed Cool Storage Unit for Promoting Rooftop Solar PV Power Generation

2020 ◽  
Vol 10 (2) ◽  
pp. 239-247
Author(s):  
Kesavan Muthaiyan ◽  
Rajamani Narayanasamy ◽  
Chidambaram Lakshmanan ◽  
Pandiyarajan Vellaichamy ◽  
Velraj Ramalingam
Keyword(s):  
Power Generation ◽  
Air Conditioning ◽  
Packed Bed ◽  
Storage Unit ◽  
Cool Storage ◽  
Renewable Power ◽  
Residential Air Conditioning ◽  
Cooling Coil ◽  
Change Material ◽  
Storage Units

The increase in the share of renewable-based power in the gross power generation in most countries causes significant concerns over the addition of renewable power with the grid, results in stability issues in most developed nations. Energy storage is an emerging technology that is considered the ultimate solution in developing microgrids with distributed renewable power generation. The cool thermal storage plays a vital role in economically promoting renewable power among different storage units. The major objective of the research work is to demonstrate the integration of residential air-conditioning systems with packed bed cool storage units to promote rooftop solar power generation for residential space cooling applications. In order to achieve the said objective, an experimental investigation was made to study the charging/discharging characteristics of a packed bed cool-storage unit combined with a chiller and a cooling coil unit suitable for small capacity air-conditioning applications. The system consists of encapsulated spherical capsules filled with a phase change material blended with distilled water and pseudomonas (nucleating agent) and the heat transfer fluid as a combination of distilled water and Mono-ethylene glycol. A cooling coil unit was connected to the cool-storage tank to transfer cool energy from the storage tank to the space to be cooled when there is a demand. The important parameters, such as instantaneous and cumulative heat transfer during the charging/discharging processes, are presented. The average COP values of the chiller during the charging operation were estimated as 1, 0.93, and 0.89 when the HTF setpoint temperatures were -6°C, -9°C, and -12°C, which shows a decrease in performance as the setpoint temperature decreases. During the discharging process, a cooling load of 2.25 kW is obtained during the first cycle of operation and gradually reduces to 0.3 kW during the sixth cycle of operation. The increase in the HTF temperature during each cycle of operation indicates that the Phase Change Material (PCM) in the balls cannot release the heat as per the demand after a certain period of discharging. Hence, decreasing the internal thermal resistance by suitable measures is essential to achieve uniform heat flux and to operate the system successfully

scholarly journals An Original Control Strategy of Storage Systems for the Frequency Stability of Autonomous Grids with Renewable Power Generation

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4391
Author(s):  
Mariano G. Ippolito ◽  
Fabio Massaro ◽  
Rossano Musca ◽  
Gaetano Zizzo
Keyword(s):  
Power Generation ◽  
Control Strategy ◽  
Storage Systems ◽  
Renewable Energy Sources ◽  
Frequency Stability ◽  
Operating Conditions ◽  
Storage Unit ◽  
Renewable Power ◽  
Renewable Power Generation ◽  
Storage Units

This work examines the operation of the autonomous power system of a geographical island assuming the integration of significant generation shares from renewable energy sources and the installation of the required storage systems. The frequency stability of the system is investigated considering different operating conditions, in terms of load demand and renewable power generation. The main focus of the work is an original control strategy specifically designed for power converters interfacing storage units to the grid. The proposed strategy is based on an extended frequency droop control, which selects specific droop settings depending on the operating mode—charge or discharge—of the storage unit. A simulation model of the whole electrical system is developed for dynamic analysis. The model also implements the possibility of including specific auxiliary frequency controls for synthetic inertia and primary reserve. The results of the simulation and analysis indicate that the proposed control strategy has a significant positive effect, making the storage units able to provide a fundamental and more effective support to the frequency stability of the system. The application of the proposed control strategy to storage units also reduces the need for a contribution to the frequency control from intermittent and variable sources, making the whole system more robust, stable and reliable.

scholarly journals Experimental investigation on packed bed cool storage system for supply-demand management in building air conditioning system suitable for micro thermal grid

2019 ◽  
pp. 265-265
Author(s):  
Rajamani Narayanasamy ◽  
Pandiyarajan Vellaichamy ◽  
Mangat Sharma ◽  
Velraj Ramalingam
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Experimental Investigation ◽  
Air Conditioning ◽  
Demand Management ◽  
Storage System ◽  
Packed Bed ◽  
Distilled Water ◽  
Air Conditioning System ◽  
Renewable Power

In most of the developed nation, the increase in percentage share of renewable power in the total power generation causes major concerns over the integration of these renewable power with the grid resulting grid instability. Energy storage is a new frontier technology which is considered as the ultimate solution in developing micro smart grid with distributed renewable power generation. Most of the hot countries like India spend nearly 24% of the electricity generated on air conditioning and food preservation. Under such scenario, among the various types of storage systems, the cool thermal storage plays a viral role to promote renewable power in an economical way. Considering the importance in the present renewable energy scenario, in the present work, an experimental investigation was performed on a packed bed cool storage system integrated with a chiller system which has major advantages in central air conditioning system for demand management strategies. The storage system consists of encapsulated spherical balls filled with a mixture of distilled water and pseudomonas (nucleating agent) as phase change material and a mixture of distilled water and Mono-ethylene glycol as heat transfer fluid. The essential parameters such as reduction in subcooling, instantaneous and cumulative heat transfer during the charging process are presented for the efficient operation.

Single-Blow Transients in Packed-Bed Storage Units With Solid-Phase Conduction by Crump’s Numerical Inversion of Laplace Transforms

1983 ◽  
Vol 105 (3) ◽  
pp. 493-497 ◽  
Author(s):  
P. -C. Lu
Keyword(s):  
Finite Difference ◽  
Linear Problem ◽  
Solid Phase ◽  
Flow Direction ◽  
Packed Bed ◽  
Laplace Transforms ◽  
Numerical Inversion ◽  
Storage Unit ◽  
Two Phase ◽  
Storage Units

A robust and fast scheme for the numerical inversion of Laplace transforms, recently established by Crump, is applied to the linear problem of two-phase (solid-and-fluid) response of a packed-bed thermal storage unit during a single-blow operation, with solid conduction in the flow direction properly considered (while neglecting the conduction and energy storage in the fluid). The scheme is shown to be capable of handling implicit solutions in the transformed domain, which are themselves to be calculated numerically on a computer. The numerical results compare very well with those obtained by other methods of attack. The comparison also discloses some rather large errors in a set of data generated by a finite difference scheme as reported in the literature.

scholarly journals Decentralized Autonomous Hybrid Renewable Power Generation

2015 ◽  
Vol 2015 ◽  
pp. 1-18 ◽  
Author(s):  
Prakash Kumar ◽  
Dheeraj Kumar Palwalia
Keyword(s):  
Power Generation ◽  
Renewable Energy Sources ◽  
Optimization Techniques ◽  
Storage Unit ◽  
Thermal Generation ◽  
Energy Storage Unit ◽  
Progressive Development ◽  
Renewable Power ◽  
Renewable Power Generation ◽  
Pv Generation

Power extension of grid to isolated regions is associated with technical and economical issues. It has encouraged exploration and exploitation of decentralized power generation using renewable energy sources (RES). RES based power generation involves uncertain availability of power source round the clock. This problem has been overcome to certain extent by installing appropriate integrated energy storage unit (ESU). This paper presents technical review of hybrid wind and photovoltaic (PV) generation in standalone mode. Associated components like converters, storage unit, controllers, and optimization techniques affect overall generation. Wind and PV energy are readily available, omnipresent, and expected to contribute major future energy market. It can serve to overcome global warming problem arising due to emissions in fossil fuel based thermal generation units. This paper includes the study of progressive development of standalone renewable generation units based on wind and PV microgrids.

scholarly journals Multi-Time-Scale Coordinated Operation of a Combined System with Wind-Solar-Thermal-Hydro Power and Battery Units

2019 ◽  
Vol 9 (17) ◽  
pp. 3574 ◽  
Author(s):  
Dongying Zhang ◽  
Ting Du ◽  
Hao Yin ◽  
Shiwei Xia ◽  
Huiting Zhang
Keyword(s):  
Power Generation ◽  
Real Time ◽  
Power Output ◽  
Time Scale ◽  
Thermal Power ◽  
Hydro Power ◽  
Renewable Power ◽  
Power Fluctuations ◽  
Pumped Storage ◽  
Storage Units

The grid connection of intermittent energy sources such as wind power and photovoltaic power generation brings new challenges for the economic and safe operation of renewable power systems. To address these challenges, a multi-time-scale active power coordinated operation method, consisting of day-ahead scheduling, hour-level rolling corrective scheduling, and real-time corrective scheduling, is proposed for the combined operation of wind-photovoltaic-thermal-hydro power and battery (WPTHB) to handle renewable power fluctuations. In day-ahead scheduling, the optimal power outputs of thermal power units, hydro-pumped storage units, and batteries are solved with the purpose of minimizing the total power generation cost. In hour-level rolling corrective scheduling, the power output plan of thermal power units and pumped storage units is modified to minimize the correction cost based on the on-off state of thermal power units determined in day-ahead scheduling. In real-time corrective scheduling stage, the feedback correction and rolling optimization-based model predictive control algorithm is adopted to modify the power output of thermal power units, hydro-pumped storage units, and batteries optimized in hour-level rolling correction scheduling, so as to ensure the economy of the correction plan and the static security of system operation. Finally, simulation results demonstrated that the proposed method can accurately track system power fluctuations, and ensure the economic and security operation of a multi-energy-generation system.

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