The Numerical Simulation of Thermal Abuse and Runaway in Lithium Ion Battery Pack

Computer simulations today play an important role in the field of science and technology. The same is true in the field of electrochemistry, where they are used mainly to model the charging and discharging processes in various types of batteries, at the various loads and temperature processes associated with it. This article deals with the possibility of modeling thermal abuse, which subsequently leads to the thermal runaway effect in a lithium ion battery pack. The simulation is accompanied by experimental measurements and comparison of the original results from the real test and simulation.

Numerical Modeling of Cyclic Voltametry

This paper deals with a new approach to numerical modeling of cyclic voltammetry using the CFD solver FLUENT. The standard use of this solver is in the field of flow and heat transfer calculations, however, it is possible to model electrochemical reactions and it also includes basic models for calculations related to batteries, such as charging and discharging processes, temperature fields, etc. Thanks to the possibility of scripting, however, it is possible to extend these tasks to a much more complex level.

Supercapacitors in Constant-Power Applications: Mathematical Analysis for the Calculation of Temperature

A set of analytical equations for the calculation of the temperature in supercapacitors operating in constant-power applications is presented in this paper. Although the main operation modes of supercapacitors are constant-current and constant-power charge and discharge, this study was focused on the latter, since both sources and loads act as constant-power systems in a wide range of power conversion facilities. The starting point of this study is the classical supercapacitor model based on electrical and thermal parameters provided by manufacturers or also obtained by experimental means. The proposed mathematical analysis is based on the so-called incomplete gamma function that presents two major advantages over previously existing methods. Firstly, it is not necessary to solve any differential equations system by means of numerical methods, which reduces the required computational effort. Secondly, no simplifications to relief the calculations are made in the computation of any variable. The new formulation renders valid solutions even for high-power demand situations. Moreover, the temperature of the supercapacitor can be expressed as a function of time or any other electrical variable in the charging and discharging processes. Therefore, the proposed formulas are especially remarkable for the electrical and thermal dimensioning of supercapacitors.

Simulation of Photovoltaic Array in DC Microgrid with MPPT using Perturb & Observe Method

If The stand-alone dc microgrid system with a PVA i.e solar renewable energy source is operated without any supportive energy storage sources like battery and supercapacitor, then it will lead to an unstable operation of a DC microgrid, so it necessitates the usage of energy storage devices for maintaining stability in the system and also to improve the efficiency of PVA we have used an MPPT controller with P&O algorithm which provides a required duty ratio for DC-DC boost converter and this converter sees that the maximum power can be transmitted from PVA to loads. In this paper, we present how we performed a simulation study by integrating Simulink models like PVA, MPPT, battery, and Supercapacitor at Point of common coupling with DC loads and observed the stability of the system with different conditions like the change of irradiances during charging and discharging processes of storage devices and observed how is the power-sharing from PVA, Battery, and supercapacitor concerning change in load.

Feasibility of Residential Combined Cooling, Heating, and Power Generation System in Canada

In order to investigate the feasibility of a combined heating, cooling, and power generation system in the residential sector, an integrated system was designed and installed at the Archetype Sustainable House (ASH) of the Toronto and Region Conservation Authority (TRCA). A Stirling engine based cogeneration unit was used to produce the thermal energy for a thermally driven chiller. The engine supplies hot water up to 95°C. The overall efficiency of up to 90% is determined for the cogeneration system. A thermo-chemical accumulator provided by the ClimateWell AB, was installed and connected to the cogeneration unit. The experimental coefficient of performance (COP) of this chiller during the test period was less than 0.4. Since the ClimateWell chiller rejects heat during both charging and discharging processes, a heat recovery system using three cascade tanks and an outdoor fan coil was designed and installed to utilize the waste heat, for domestic hot water production. A complete TRNSYS model of the tri-generation system was used to verify the experimental results.

Feasibility of Residential Combined Cooling, Heating, and Power Generation System in Canada

In order to investigate the feasibility of a combined heating, cooling, and power generation system in the residential sector, an integrated system was designed and installed at the Archetype Sustainable House (ASH) of the Toronto and Region Conservation Authority (TRCA). A Stirling engine based cogeneration unit was used to produce the thermal energy for a thermally driven chiller. The engine supplies hot water up to 95°C. The overall efficiency of up to 90% is determined for the cogeneration system. A thermo-chemical accumulator provided by the ClimateWell AB, was installed and connected to the cogeneration unit. The experimental coefficient of performance (COP) of this chiller during the test period was less than 0.4. Since the ClimateWell chiller rejects heat during both charging and discharging processes, a heat recovery system using three cascade tanks and an outdoor fan coil was designed and installed to utilize the waste heat, for domestic hot water production. A complete TRNSYS model of the tri-generation system was used to verify the experimental results.

Underground Energy Storage Utilizing Concrete Building Foundation: Experimental and Numerical Approach

Space heating and cooling represents 63% of total building energy demand. In the present study, the concept of concrete foundation piles was used as an underground storage medium. This system requires no additional drilling costs or space, unlike conventional boreholes. A lab-scaled experiment facility was designed to experimentally investigate the thermal response of a concrete pile during the charging and discharging processes. The amount of energy stored and released during each process was evaluated. A flow rate parametric study was also conducted to explore the effect of the laminar and turbulent flow behaviour. In order to complement the experimental study, an extensive CFD model was developed and compared with the experimental data. There was good agreement between the numerical and experimental results for each process at different flow rates. The results revealed that increasing the flow rate increases not only the heat rejection and extraction but also the storage efficiency. Keywords: borehole, energy pile, thermal storage, thermal response, ground source heat pump

Underground Energy Storage Utilizing Concrete Building Foundation: Experimental and Numerical Approach

Space heating and cooling represents 63% of total building energy demand. In the present study, the concept of concrete foundation piles was used as an underground storage medium. This system requires no additional drilling costs or space, unlike conventional boreholes. A lab-scaled experiment facility was designed to experimentally investigate the thermal response of a concrete pile during the charging and discharging processes. The amount of energy stored and released during each process was evaluated. A flow rate parametric study was also conducted to explore the effect of the laminar and turbulent flow behaviour. In order to complement the experimental study, an extensive CFD model was developed and compared with the experimental data. There was good agreement between the numerical and experimental results for each process at different flow rates. The results revealed that increasing the flow rate increases not only the heat rejection and extraction but also the storage efficiency. Keywords: borehole, energy pile, thermal storage, thermal response, ground source heat pump

Cooperative Operation Schedules of Energy Storage System and Demand Response Resources Considering Urban Railway Load Characteristic under a Time-of-Use Tariff

This paper proposes an algorithm for the cooperative operation of air conditioning facilities and the energy storage system (ESS) in railway stations to minimize electricity. Unlike traditional load patterns, load patterns of an urban railway station can peak where energy charge rates are not high. Due to this possibility, if applying the traditional peak-reduction algorithm to railway loads, energy changes can increase, resulting in higher electricity bills. Therefore, it is required to develop a new method for minimizing the sum of capacity charges and energy charges, which is a non-linear problem. To get a feasible solution for this problem, we suggest an algorithm that optimizes the facility operation through two optimizations (primary and secondary). This method is applied to the air-quality change model for operating air conditioning facilities as demand-response (DR) resources in railway stations. This algorithm makes it possible to estimate operable DR capacity every hour, rather than calculating the capacity of DR resources conservatively in advance. Finally, we perform a simulation for the application of the proposed method to the operation of DR resources and ESS together. The simulation shows that electricity bills become lowered, and the number of charging and discharging processes of ESS is also reduced.