An innovative trigeneration system using biogas as renewable energy

One of the ways to decrease the global primary energy consumption and the corresponding greenhouse gas emissions is the application of the combined cooling, heating and power generation technologies, known as trigeneration system. In this research an innovative trigeneration system, composed by an absorption heat pump, a mechanical compression heat pump, a steam plant, and a heat recovery plant is developed. The low tem- perature heat produced by absorption chiller is sent to a mechanical compression heat pump, that receives pro- cess water at low temperature from the heat recovery plant and bring it to higher temperatures. The trigeneration system is fed by biogas, a renewable energy. A design and a simulation of the system are developed by ChemCad 6.3 software. The plant produces 925 kW of electrical energy, 2523 kW of thermal energy and 473 kW of cooling energy, by the combustion of 3280 kW of biogas. Primary energy rate （P.E.R.） is equal 1.04 and a sensitivity analysis is carried out to evaluate the effect of cooling capacity, produced electrical energy and process water temperature. The first has a negative effect, while other parameters have a positive effect on P.E.R. Compared to a cogeneration system, the tdgeneration plant produces the 28% higher of power and the 40% lower of carbon dioxide emissions. An economic analysis shows that the plant is economically feasible only consid- ering economic incentives obtained by the use of heat pumps and steam plant at high efficiency. Saving 6431 t.a-1 corresponding to 658000 EUR.a-1 of incentives, the plant has a net present value （N.P.V.） and a pay back period （P.B.P.） respectively equal to 371000 EUR and 4 year. Future works should optimize the process considering cost and energetic efficiency as the two objective functions.

Multiperspective Analysis of Microscale Trigeneration Systems and Their Role in the Crowd Energy Concept

The energy system of the future will transform from the current centralised fossil based to a decentralised, clean, highly efficient, and intelligent network. This transformation will require innovative technologies and ideas like trigeneration and the crowd energy concept to pave the way ahead. Even though trigeneration systems are extremely energy efficient and can play a vital role in the energy system, turning around their deployment is hindered by various barriers. These barriers are theoretically analysed in a multiperspective approach and the role decentralised trigeneration systems can play in the crowd energy concept is highlighted. It is derived from an initial literature research that a multiperspective （technological, energy-economic, and user） analysis is necessary for realising the potential of trigeneration systems in a decentralised grid. And to experimentally quantify these issues we are setting up a microseale trigeneration lab at our institute and the motivation for this lab is also briefly introduced.

Biofuel-driven trigeneration systems for non-residential building applications:A holistic assessment from the energy,environmental and economic perspectives

In the metropolises,it is unlikely to use merely solar and wind energy to pursue zero carbon building design.However,it would become possible if biofuel-driven trigeneration systems(BDTS)are adopted.It is thus essential to assess the application opportunity of BDTS in a holistic way.In this study,BDTS offered definite primary energy saving of up to 15%and carbon emissions reduction of at least 86%in different types of non-residential buildings as compared to the conventional systems.With 24/7 operation for the hotel and hospital buildings,the corresponding BDTS could even achieve zero carbon emissions.All the BDTS primed with compression-ignition internal combustion engine were not economically viable even in running cost due to the high local biodiesel price level.The BDTS primed with spark-ignition engine and fueled by biogas,however,would have economic merit when carbon price was considered for the conventional systems that fully utilize fossil fuels.Adoption of carbon tax and social cost could have the payback ceilings of 8 years and 2 years respectively for most of building types.Consequently,the results could reflect the application potential of BDTS for non-residential buildings,leading the pathway to carbon neutrality for sustainable sub-tropical cities.

Energy and Exergy Efficiency Analysis of Advanced Adiabatic Compressed Air Energy Storage Based Trigeneration Energy Hub

With growing public awareness of decarbonization and increasing penetration of renewable generation,energy storage is in great need.Advanced adiabatic compressed air energy storage(AA-CAES)is capable of producing power,heating and cooling,making it an ideal choice of an environmental-friendly energy hub.This paper proposes an energy and exergy efficiency analysis for an AA-CAES based trigeneration energy hub.Impact of power storage and heat load supply rates on energy output efficiency and total exergy losses are analyzed.Based on the proposed model,optimal configuration of power storage and heat load supply rates can be determined under different purposes.According to basic thermodynamic principles,the proposed method calculates trigeneration capability estimates considering energy grade difference and multi-dimension energy distribution,which can demonstrate more energy conversion properties of the system.Case studies verify that the proposed method can provide various characteristic analyses for an energy hub and its application in actual systems proves computation accuracy.Integrative energy efficiency is improved compared to pursuing maximum electricity-to-electricity efficiency.

Parametric analysis of a solar-driven trigeneration system with an organic Rankine cycle and a vapor compression cycle

The objective of this paper is the parametric analysis of a solar-fed trigeneration system ideal for the building sector that produces useful heat,electricity and cooling.The examined unit is driven by 100 m^(2)of parabolic trough collectors which are combined with a sensible storage tank with thermal oil.An organic Rankine cycle is fed by solar useful heat production and it produces electricity while a part of its power drives a vapor compression cycle with R290.Heating is also produced by separate heat exchangers in the solar loop.The parametric analysis is conducted in steady-state conditions with a developed model in Engineering Equation Solver.The examined parameters are the following:superheating degree in the turbine inlet,cooling production,heating production,solar beam irradiation intense,sun angle,pressure level in the turbine inlet and heat source temperature level.For the nominal scenario of 10 kW cooling production at 5°C and 10 kW heating production at 60°C,the system produces 6.14 kW electricity,while the exergy and energy efficiencies are found 12.14%and 37.34%respectively.Assuming that the system operates 2500 h yearly,the simple payback period of the investment is calculated at 8.5 years.The maximum examined values for both heating and cooling production are at 20 kW.

Numerical and Experimental Study of a Multi-Generation Desalination Power Plant

The demand for more efficient power generation is not only a prominent subject for environmental reasons but for economic reasons as well. Continuing growth in population contributes to more and more consumption of fresh water, demanding less expensive desalination production, especially in the regions with little or no natural fresh water. Multigeneration desalination power plants may provide solutions to these issues through advanced and efficient designs that are capable of supplying fresh water and power to remote or arid regions of the world. This paper examines the flexibility and versatility of multigeneration systems to showcase the myriad of combinations that are available to accommodate any specific application. It also proposes a specific design for a multi-stage flash desalination system that is powered directly by the exhaust gases of a natural gas micro-turbine capable of producing around 1 MW of electrical power. The performance characteristics, the fresh water produced per kW and the overall plant efficiency, are numerically investigated and compared with previous designs that were analyzed on a larger scale. It is determined that the multigeneration system can produce 56,891 gallons of fresh water per day and an estimated 4.07 tons of salt per day and that a small scale multi-generation desalting systems is feasible.

Analysis by Indicators Performance of the Conceptual Structures mCCHP-SE Using Renewable Energy Sources

This paper refers to an integrated mCCHP （micro-combined cooling heat and power） systems dedicated for isolated residents with energetic independence. The only energy sources are wood pellet and solar energy. The proposed trigeneration system is based on mCHP （micro-combined heat and power） unit with Stirling engine, photovoltaic panels, thermal solar collector and pellet boiler. The proposed mCCHP system utilizes the exceeding amount of heat in the summer for producing the necessary cooling. A residential building with known energy consumption is determined load curves that must be covered by mCCHP system. The paper analyzes four structures of trigeneration systems with thermal activation chiller and two structures of trigeneration systems with mechanical compression chiller. Performance indicators are determined based on energy balance equations for each variant. It compares the performances and establishes the best option.