Combined cooling, heating and power generation (CCHP) systems can be utilized for commercial or multi-family residential buildings as efficient and reliable means to satisfy building power requirements and thermal loads. In the present paper, a CCHP system consist of a Bryton cycle, an Organic Rankine cycle (ORC) and an absorption Ammonia-water cycle is considered. A detailed model is developed via MATLAB to assess the performance of the considered cycle from energy, exergy and economic perspectives. Appropriate ranges for inputs are considered and the first law efficiency, second law efficiency and ECOP of the cycle are determined as 77.17%, 33.18% and 0.31 respectively for the given inputs. Exergy destruction rates are found to be greatest primarily in the generator and the absorber of refrigeration cycle followed by the combustion chamber. The total exergy destruction rate in the system is found as 5311.51 kW. The exergoeconomic analysis is performed using SPECO approach to evaluate cost flow rate equations of the complete system and its individual components. Summation of capital investment cost rates and cost rates associated with the exergy destruction for the whole system is found as $18.245 per hour. A parametric study is also performed to provide an understanding on the effect of total pressure ratio and turbine inlet temperature of ORC on the performance of the system.

Integration of non-dispatchable renewable energy sources such as wind and solar into the grid is challenging due to the stochastic nature of energy sources. Hence, electrical hubs (EH) and virtual power plants that combine non-dispatchable energy sources, energy storage and dispatchable energy sources such as internal combustion generators and micro gas turbines are getting popular. However, designing such energy systems considering the electricity demand of a neighborhood, curtailments for grid interactions and real time pricing (RTP) of the main utility grid (MUG) is a difficult exercise. Seasonal and hourly variation of electricity demand, potential for each non-dispatchable energy source and RTP of MUG needs to be considered when designing the energy system. Representation of dispatch strategy plays a major role in this process where simultaneous optimization of system design and dispatch strategy is required. This study presents a bi-level dispatch strategy based on reinforced learning for simultaneous optimization of system design and operation strategy of an EH. Artificial Neural Network (ANN) was combined with a finite state controller to obtain the operating state of the system. Pareto optimization is conducted considering, lifecycle cost and system autonomy to obtain optimum system design using evolutionary algorithm.

In the last 50 years, the province of Ontario has lost electrical power at various times, which has challenged Ontario’s emergency-response capabilities. In addition to the loss of electricity supply, there were concerns regarding access to diesel fuels and gasoline due to loss of electrical power to pump the fuel. However, natural gas and propane are a viable alternative energy supply in an emergency scenario. The purpose of this project is to assess the role of natural gas in an emergency scenario and potential areas for further optimization to meet energy needs within the region of Durham, Ontario. An energy management model for the region of Durham has been developed for both electricity and natural gas. This model can be used to assess the impact of an emergency scenario on energy supply. This was achieved by researching different types of critical facilities such as hospitals, emergency services, schools, water/sewage facilities, community centers, shopping centers and gas stations and their reliance upon electricity and natural gas. Major shopping centers were included within this project as they provide communities with medical, grocery and basic needs. Data gathered for 415 facilities was incorporated into a Visual Basic model. The data was based on floor space, population, fleet size, water consumption, fuel types and energy use behavior. Facilities were divided into categories based on sizes of less than 5,000 m 2 , between 5,000 m 2 and 15,000 m 2 , and greater than 15,000 m 2 for the purposes of the model. Unique facilities such as the six water treatment facilities and the ten E.M.S stations were assessed individually. The data was then used to create a model that related the available electricity and natural gas to the various types of facilities in the Durham Region. The results show that natural gas infrastructure is already in place in the Region of Durham and many critical facilities currently use natural gas to supply heat energy. Hence, modest changes (cogeneration plants/ micro gas turbines) in the current infrastructure could be implemented to ensure emergency power is available from natural gas in a loss of electricity scenario and further improve the resiliency of the region of Durham in an emergency scenario.

This paper is to propose a basic concept of marine renewable energy power plant system as a dispersed one, which is composed of a marine biomass plantation and a micro gas turbine. In this system, high-efficiency compact heat exchanger becomes necessary for the limit of the marine plant space. The author has already reported about a steady and transient heat transfer process for CO 2 flowing over a horizontal plate under wide experimental conditions assuming a plate-type heat exchanger. For the heat transfer enhancement of the heat exchanger, the twisted plates were inserted in the tube and parallel plates. In the experiment, the overall heat transfer coefficients of the heat exchanger for carbon dioxide gas (CO 2 ) are measured to construct a fundamental database for the proposed marine renewable energy system. Moreover, the three-dimensional analysis of the twisted heat exchanger has been conducted using the commercial CFD code, CFD2000. The twisted plate with a thickness of 0.3 mm is inserted in a tube which inner diameter is 7 mm. The gas flow velocities are ranged from 2.5 to 7.18 m/s for the inlet gas temperature of 323K. In the experiment, the overall heat transfer coefficient increases as the gas flow velocity increases. In the numerical simulation, the fluid structure in the tube has been changed caused by the twisted plate. The flow velocity near the twisted plate increases due to the blockage of the flow-pass. The temperature distribution was affected by the helically twisting fluid motion.

In this work, a biogas fuelled power generation system is considered. The system is constituted by a molten carbonate fuel cell (MCFC) coupled with a micro gas turbine for electricity generation and supplying heat to an anaerobic digester which produces biogas from urban wastes. The work starts with a time dependent model of the digester, obtained from measured data, relating the waste characteristics with the biogas mass flow rate. The thermal flux required by the digester is also related to the waste disposal. The optimal design of the MCFC system is then investigated considering both thermodynamic and economic objective functions, calculated in a proper design condition. The effects of variation in fuel quality, ambient temperature and component performances are finally analyzed.

In this paper, a biogas fuelled power generation system is considered. The system is based on a molten carbonate fuel cell (MCFC) stack integrated with a micro gas turbine for electricity generation, coupled with a pressure swing absorption system (PSA) for hydrogen production. The aim of this work is the optimal design of the system plant considering thermodynamic and economic objective functions. The procedure starts from system decomposition in two parts: the heat transfer network and the other components (in the following indicated as the “power components”). Design parameters are the pressure ratio, some operating temperatures and mass flow rates. For each set of the design parameters, the corresponding thermodynamic conditions of flows entering and exiting the power components are obtained. Then the heat flux recovered in the heat transfer network and the primary energy consumption are determined. Economic analysis is performed by considering function costs for the power components and a relation between the heat transfer network cost and the main energy requirements. The latter is obtained through analysis of a few heat transfer network configurations.

This study deals with types of micro cogeneration (or micro combined heat and power, MCHP) systems and reviews energetic and exergetic analysis of MCHP systems, which are also called building cogeneration systems. These are classified as micro and macro cogeneration systems and figured within subgroups. Previously conducted studies on exergy and energy analyses of internal combustion engines (micro turbines), external combustion engines (Ericsson engines), fuel cells (solid oxide fuel cells) and thermophotovoltaic systems are treated in this paper. The main objectives of this study are to classify MCHP systems used in building cogeneration systems, to introduce types of MCHP systems and to better define micro cogeneration systems in the light of previously conducted studies. In this regard, energetic and exergetic efficiencies of various MCHP systems are graphically obtained. Under grouping presented MCHP systems, internal combustion engines based MCHP systems are defined to be the best choice with energetic and exergetic efficiency values of 86.0% and 40.31%, respectively. Micro gas turbines and Ericson engine based micro cogeneration systems are also obtained as valuable systems with the energetic values of 75.99% and 65.97% and exergetic values of 35.8% and 38.5%, respectively. However, in this building cogeneration group, energetic and exergetic efficiencies of the thermophotovoltaic systems have 65.0% and 15.0%, respectively. It may be concluded that system choice depends on the type of the system, energy flow of the system, system parts and developments, while building, system capacity, comfort and maintenance are the other factors to be considered.