Development and Test of a Fuel Cell Based Micro-CHP System

2015 ◽  
Vol 1092-1093 ◽  
pp. 175-180
Author(s):  
Dong Lai Xie ◽  
Bing Qi Wang

Fuel cell based micro combined heat and power (micro-CHP) systems are residential scale clean energy conversion unit. It employs fuel cells in a compact system that converts natural gas, propane or other fuels into both electricity and heat, which increases efficiency by simultaneously generating power and heat for one unit, on-site within a home. A prototype system consisting of a natural gas steam reforming unit, CO cleaning unit, PEM fuel cell stack, waste heat recovery unit and auxiliary unit is integrated. Test results of the prototype show that it can start within an hour and the syngas produced can meet the fuel cell’s requirements. The prototype’s electric power and thermal power are 200W and 530W respectively, while the electric and thermal efficiency are 15.4% and 40.9% respectively.

Author(s):  
James F. Walton ◽  
Andrew Hunsberger ◽  
Hooshang Heshmat

In this paper the authors will present the design and preliminary test results for a distributed electric generating system that uses renewable energy source for economical load-following and peak-shaving capability in an oil-free, high-speed micro-turboalternator system using compliant foil bearings and a permanent magnet alternator. Test results achieved with the prototype system operating to full speed and under power generating mode will be presented. A comparison between predicted and measured electrical output will also be presented up to a power generating level of 25 kWe at approximately 55,000 rpm. The excellent correlation between design and test provides the basis for scale up to larger power levels. Based upon the turboalternator test results a thermodynamic cycle analysis of a system using low grade waste heat water at approximately 100 C will be reviewed. The tradeoff study results for a series of environmentally friendly refrigerant working fluids will also be presented including sensitivity to vaporization and condensing temperatures. Based on the cycle and pinch point analyses predicted maximum output power was determined. Finally a preliminary turbine design for the selected R134a working fluid was completed. The results of this study show that a net output power level of greater than 40 kW is possible for approximately 240 l/m flow of water at 100C is possible.


2005 ◽  
Vol 2 (4) ◽  
pp. 263-267 ◽  
Author(s):  
Darrell D. Massie ◽  
Daisie D. Boettner ◽  
Cheryl A. Massie

As part of a one-year Department of Defense demonstration project, proton exchange membrane fuel cell systems have been installed at three residences to provide electrical power and waste heat for domestic hot water and space heating. The 5kW capacity fuel cells operate on reformed natural gas. These systems operate at preset levels providing power to the residence and to the utility grid. During grid outages, the residential power source is disconnected from the grid and the fuel cell system operates in standby mode to provide power to critical loads in the residence. This paper describes lessons learned from installation and operation of these fuel cell systems in existing residences. Issues associated with installation of a fuel cell system for combined heat and power focus primarily on fuel cell siting, plumbing external to the fuel cell unit required to support heat recovery, and line connections between the fuel cell unit and the home interior for natural gas, water, electricity, and communications. Operational considerations of the fuel cell system are linked to heat recovery system design and conditions required for adequate flow of natural gas, air, water, and system communications. Based on actual experience with these systems in a residential setting, proper system design, component installation, and sustainment of required flows are essential for the fuel cell system to provide reliable power and waste heat.


2019 ◽  
Vol 7 (11) ◽  
pp. 397 ◽  
Author(s):  
Marco Altosole ◽  
Ugo Campora ◽  
Silvia Donnarumma ◽  
Raphael Zaccone

Waste Heat Recovery (WHR) marine systems represent a valid solution for the ship energy efficiency improvement, especially in Liquefied Natural Gas (LNG) propulsion applications. Compared to traditional diesel fuel oil, a better thermal power can be recovered from the exhaust gas produced by a LNG-fueled engine. Therefore, steam surplus production may be used to feed a turbogenerator in order to increase the ship electric energy availability without additional fuel consumption. However, a correct design procedure of the WHR steam plant is fundamental for proper feasibility analysis, and from this point of view, numerical simulation techniques can be a very powerful tool. In this work, the WHR steam plant modeling is presented paying attention to the simulation approach developed for the steam turbine and its governor dynamics. Starting from a nonlinear system representing the whole dynamic behavior, the turbogenerator model is linearized to carry out a proper synthesis analysis of the controller, in order to comply with specific performance requirements of the power grid. For the considered case study, simulation results confirm the validity of the developed approach, aimed to test the correct design of the whole system in proper working dynamic conditions.


2021 ◽  
Author(s):  
Jeremy Liu ◽  
Rasish Khatri ◽  
Freddie Sarhan ◽  
Eric Blumber

Abstract A family of “flow-through” turboexpander-generators (TEGs) has been developed by Calnetix Technologies for hydrogen and natural gas pressure letdown applications. A flow-through TEG includes an axial expansion turbine and can be installed directly between two flanges of an existing pipeline. TEGs can be used to generate power throughout the hydrogen and natural gas transmission infrastructure using existing pressure differentials wherever a Joule-Thomson valve is located. These can be upstream, at terminal stations, and downstream, at governor stations. The expander drives a synchronous permanent magnet high-speed generator supported by active magnetic bearings. This paper describes the innovative axial flow-through system architecture, including the use of process gas for cooling the generator rotor and stator. The primary focus of the paper is the economic analysis of the application. Various TEG subsystem design choices and their impact on cost are discussed, including the generator, bearing, expander wheel, seal, and touchdown bearing resilient mount designs. A payback analysis shows that the natural gas TEG has a payback of 2.1 years when a heat exchanger is required for preheating the gas and 1.9 years when waste heat can be used. The hydrogen TEG has a payback of 2.0 years, and does not require external preheating. Finally, a comparison of this technology with other clean energy solutions is presented, using the Levelized Cost of Electricity (LCOE) formulation. The analysis confirms that the LCOE of the expander-generator ($0.40 per megawatt-hour) compares favorably with other types of conventional and renewable energy technologies on a cost basis.


2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Doerte Laing ◽  
Dorothea Lehmann ◽  
Michael Fiß ◽  
Carsten Bahl

Efficient energy storage is vital to the success of solar thermal power generation and industrial waste heat recovery. A sensible heat storage system using concrete as the storage material has been developed by the German building company Ed. Züblin AG and the German Aerospace Center (DLR). A major focus was the cost reduction in the heat exchanger and the high temperature concrete storage material. For live tests and further improvements, a 20 m3 solid media storage test module connected to an electrically heated thermal oil loop was built in Stuttgart. The design of the test module and the test results are described in this paper. By the end of November 2008, the second generation solid media storage test module had accumulated five months of operation in the temperature range between 300°C and 400°C and almost 100 thermal cycles with a temperature difference of 40 K. The tests will be continued in 2009.


Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3893 ◽  
Author(s):  
Han Chang ◽  
In-Hee Lee

The problem of air pollution in Korea has become progressively more serious in recent years. Since electricity is advertised as clean energy, some newly developed buildings in Korea are using only electricity for all energy needs. In this research, the annual amount of air pollution attributable to energy under the traditional method in a dormitory building, which is supplying both natural gas and electricity to the building, was compared with the annual amount of air pollution attributable to supplying only electricity. The results showed that the building using only electricity emits much more air pollution than the building using electricity and natural gas together. Under the traditional method of energy supply, a residential solid oxide fuel cell cogeneration system (SOFC–CGS) for minimizing environmental pollution of the building was simulated. Furthermore, as a high load factor could lead to high efficiency of the SOFC–CGS, sharing of the SOFC–CGS by multi-households could increase its efficiency. Finally, the environmental pollution from using one system in one household was compared with that from sharing one system by multi-households. The results showed that the environmental pollution from sharing the system was relatively higher but still similar to that when using one system in one household.


2020 ◽  
Vol 197 ◽  
pp. 06023
Author(s):  
Antonio Mariani ◽  
Biagio Morrone ◽  
Maria Vittoria Prati ◽  
Andrea Unich

Waste heat recovery can be a key solution for improving the efficiency of energy conversion systems. Organic Rankine Cycles (ORC) are a consolidated technology for achieving such target, ensuring good efficiencies and flexibility. ORC systems have been mainly adopted for stationary applications, where the limitations of layout, size and weight are not stringent. In road transportation propulsion systems, the integration between the powertrain and the ORC system is difficult but still possible. The authors investigated an ORC system bottoming a spark ignited internal combustion engine (ICE) powering a public transport bus. The bus, fuelled by natural gas, was tested in real driving conditions. Exhaust gas mass flow rate and temperature have been measured for calculating the thermal power to be recovered in the ORC plant. The waste heat was then used as energy input in a model simulating the performance of an ORC system. The heat transfer between the exhaust gases and the ORC fluid is crucial for the ORC performance. For this reason, attention was paid to considering the interaction between hot fluid temperature and ORC maximum pressure. ORC performance in terms of real cycle efficiency and power produced were calculated considering n-Pentane as working fluid. The fuel consumption was reduced from 271.5 g/km to 261.4 g/km over the driving cycle, corresponding to 3.7% reduction.


Author(s):  
Paolo Colbertaldo ◽  
Giulio Guandalini ◽  
Elena Crespi ◽  
Stefano Campanari

Abstract A key approach to large renewable energy sources (RES) power management is based on implementing storage technologies, including batteries, power-to-hydrogen (P2H), pumped-hydro, and compressed air energy storage. Power-to-hydrogen presents specific advantages in terms of suitability for large-scale and long-term energy storage as well as capability to decarbonize a wide range of end-use sectors, e.g., including both power generation and mobility. This work applies a multi-nodal model for the hourly simulation of the energy system at a nation scale, integrating the power, transport, and natural gas sectors. Three main infrastructures are considered: (i) the power grid, characterized by instantaneous supply-demand balance and featuring a variety of storage options; (ii) the natural gas network, which can host a variable hydrogen content, supplying NG-H2 blends to the final consumers; (iii) the hydrogen production, storage, and re-electrification facilities. The aim of the work is to assess the role that can be played by gas turbine-based combined cycles in the future high-RES electric grid. Combined cycles (GTCCs) would exploit hydrogen generated by P2H implementation at large scale, transported through the natural gas infrastructure at increasingly admixed fractions, thus closing the power-to-power (P2P) conversion of excess renewables and becoming a strategic asset for future grid balancing applications. A long-term scenario of the Italian energy system is analyzed, involving a massive increase of intermittent RES power generation capacity and a significant introduction of low-emission vehicles based on electric drivetrains (pure-battery or fuel-cell). The analysis highlights the role of hydrogen as clean energy vector, not only for specific use in new applications like fuel cell vehicles and stationary fuel cells, but also for substitution of fossil fuels in conventional combustion devices. The study also explores the option of repowering the combined cycles at current sites and evaluates the effect of inter-zonal limits on power and hydrogen exchange. Moreover, results include the evaluation of the required hydrogen storage size, distributed at regional scale or in correspondence of the power plant sites. Results show that when extra hydrogen generated by P2H is fed to GTCCs, up to 17–24% H2 use is achieved, reaching up to 70–100% in southern regions, with a parallel reduction in fossil NG input and CO2 emissions of the GTCC plants.


Author(s):  
Daisie D. Boettner ◽  
Cheryl A. Massie ◽  
Darrell D. Massie

As part of a one-year Department of Defense demonstration project, proton exchange membrane fuel cell systems have been installed at three residences to provide electrical power and waste heat for domestic hot water and space heating. The 5 kW-capacity fuel cells operate on reformed natural gas. These systems operate at preset levels providing power to the residence and to the utility grid. During grid outages, the residential power source is disconnected from the grid and the fuel cell system operates in standby mode to provide power to critical loads in the residence. This paper describes lessons learned from installation and operation of these fuel cell systems in existing residences. Issues associated with installation of a fuel cell system for combined heat and power focus primarily on fuel cell siting, plumbing external to the fuel cell unit required to support heat recovery, and line connections between the fuel cell unit and the home interior for natural gas, water, electricity, and communications. Operational considerations of the fuel cell system are linked to heat recovery system design and conditions required for adequate flow of natural gas, air, water, and system communications. Based on actual experience with these systems in a residential setting, proper system design, component installation, and sustainment of required flows are essential for the fuel cell system to provide reliable power and waste heat.


2003 ◽  
Vol 27 (2) ◽  
pp. 121-134
Author(s):  
R. J. Spiegel

This study examines the integrated use of wind turbines, natural gas and high temperature fuel cells to produce methanol. The purpose is to produce transportation fuel from national local resources with the least polluting emissions. The fuel would displace petroleum imports and reduce greenhouse gas emissions by converting wind power, natural gas and fuel cell energy. The proposal includes the utilization of waste heat and exhaust gas (CO2) into clean liquid fuel (methanol) that is compatible with future vehicle technology based on fuel cells. Potential designs are presented and assessed for methanol yield, production cost and emissions reductions. Results show that this process (a) can produce significant amounts of vehicle fuel, comparable to what is annually consumed in the U.S. (∼19 EJ/y); (b) can minimize emissions; (c) is potentially cost competitive with other technologies that produce methanol; and (d) is compatible with the requirements of a new generation of vehicles based on fuel cells.


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