In today's POWER SYSTEMS, the use of methods that can increase the energy efficiency AND reduce the cost of the generated energy has received much attention. One of these methods is the use of the COMBINED HEAT AND POWER (CHP) plants that simultaneously can generate the electric AND thermal POWERs. In the conventional thermal POWER plants, the thermal energy of the working fluid coming out from the turbine is dissipated that result in low efficiency. However, it can be used for the HEATing purposes in the CHP units that result in the high efficiency of these plants. Due to the wide use of the CHP units in the POWER system, different aspects of the POWER system such as operation may be affected that must be studied. In this paper, the study of the POWER system operation integrated with the CHP plants is performed. For this purpose, the PJM method that considers the reliability-based indices such as unit commitment risk is utilized. Moreover, a four-state reliability model is developed different types of the CHP units including gas turbine, steam turbine, reciprocating engine, micro-turbine AND fuel cell technologies. In the proposed model, both the failure of composed components AND the participation of the CHP units in the thermal POWER generation are considered. To determine the probabilities of different states of the proposed model, matrix multiplication technique is used. Based on the PJM technique, the numerical results associated to the operation studies of the RBTS AND IEEE-RTS that are given AND the unit commitment risk AND the required spinning reserve of these SYSTEMS calculated considering the effect of the CHP units.

An optimization method has been developed to determine the optimal capacities for the CHP AND boiler such that thermal AND electrical energy demANDs can be satisfied with high cost efficiency. The proposed method offers an operational strategy in order to determine the optimum value for boiler AND CHP capacities which maximize an objective function based on the net present value (NPV). The reduction in operational strategy expenses arising from the monetary cost of the credit attainable by air pollution reduction is also taken into account in evaluation of the objective function. The optimal value for boiler AND CHP capacities AND the resulting projection for the optimal value of the objective function are derived using a hybrid optimization method involving the particle swarm optimization (PSO) AND the linear programming algorithms. The viability of the proposed method is demonstrated by analyzing the decision to construct a CHP system for a typical hospital.

The paper presents a detailed solid oxide fuel cell (SOFC) model that is specifically developed for the performance evaluation of planar SOFC stacks in COMBINED HEAT AND POWER (CHP) SYSTEMS. The developed model includes the mass, momentum, thermal AND electrochemical analysis, as well as the kinetic models of hydrocarbon reactions. The electrochemical model includes a complete evaluation of ohmic, activation AND diffusion polarisations. To increase the accuracy of the model; methane reforming AND water-gas shift reactions, several layers of temperature, radiation HEAT transfer model AND material temperature dependent property are also applied to the model. The model is also validated with available numerical AND experimental data for a high temperature SOFC with internal reforming, showing the capacity to accurately predict its operating conditions. Finally, sensitivity analyses on fuel utilization factor AND on air excess ratio are performed to investigate the effects of different key parameters.

This study was conducted during summer AND winter of 2018- 2019 in the agricultural research field of Shahid Chamran University. Experimental design was split- plot based on RCBD with three replications. The main plot was the type of agricultural system in three levels including conventional (Conv), organic (Org) AND sustainable (Sust) (integrated between Conv AND Org) AND sup- plot was the type of pre- cultivated crop in sequence with wHEAT including cultivation of mung bean (M- W), corn (C- W), sesame (S- W) AND fallow (F- W). Yield quantity (yield AND its component) AND quality (grain protein), an estimate of photosynthesis matter transfer index of wHEAT AND soil organic carbon (SOC) after one double-cropping were measured. The result showed that the highest (545.04 g/m2) AND the lowest (409.28 g/m2) seed yields were obtained in Conv AND Org respectively. In contract, with the changing type of system from Conv to Org, grain protein was increased significantly (from 8.3 to 9.6 %). In addition, the highest (535.47 g/m2) yield of wHEAT was obtained from M- W double cropping. On the other hANDs the highest remobilization AND current photosynthesis matter were obtained in the organic agricultural system with M- W AND conventional with M- W double cropping. The situation of SOC showed that the highest (33.18 mg/g) SOC was obtained in the organic agricultural system with C- W double cropping. The reason for improving SOC in the organic AND sustainable agricultural system was application of organic matter (compost AND vermicompost) AND crop residue management. Totally, from the crop ecology point of view, sustainable agricultural method with a sequence of M- W was the most desirable system.

Energy efficiency is one of the most important issues in the POWER system studies AND many methods are used to improve POWER SYSTEMS efficiency. COMBINED cool, HEAT AND POWER (CCHP) SYSTEMS are one of the most important technologies that can improve POWER system efficiency AND these SYSTEMS use their excess HEAT for supplying HEAT AND cool loads.This paper presents a framework for optimal operation of CCHP SYSTEMS in a microgrid. At first the unit cost functions are used to optimize operation of CCHP units. Then the algorithm determines the optimal operating strategy of microgrid units. A multi-criteria operation optimization method is proposed that uses primary energy consumption, pollution emissions AND operating costs as criteria.The case study is performed for a nine bus microgrid AND the results are compared with reference articles results AND the advantage of the proposed method is investigated.