Independent Evaluation of Measured Performance Data for Cutting-Edge Combined Heat and Power Fuel Cell Systems Installed in Buildings

Author(s):  
Heather E. Dillon ◽  
Whitney G. Colella

Pacific Northwest National Laboratory (PNNL) is working with industry to independently monitor up to fifteen distinct 5 kilowatt-electric (kWe) combined heat and power (CHP) high temperature (HT) proton exchange membrane (PEM) fuel cell systems (FCSs) installed in light commercial buildings. This research paper discusses an evaluation of the first six months of measured performance data acquired at a one-second sampling rate from real-time monitoring equipment attached to the FCSs at building sites. Engineering performance parameters are independently evaluated. Based on an analysis of the first few months of measured operating data, FCS performance is consistent with manufacturer-stated performance. Initial data indicate that the FCSs have relatively stable performance and a long term average production of about 4.57 kWe of power. This value is consistent with, but slightly below, the manufacturer’s stated rated electric power output of 5 kWe. The measured system net electric efficiency has averaged 33.7%, based on the higher heating value (HHV) of natural gas fuel. This value, also, is consistent with, but slightly below, the manufacturer’s stated rated electric efficiency of 36%. The FCSs provide low-grade hot water to the building at a measured average temperature of about 48.4°C, lower than the manufacturer’s stated maximum hot water delivery temperature of 65°C. The uptime of the systems is also evaluated. System availability can be defined as the quotient of total operating time compared to time since commissioning. The average values for system availability vary between 96.1 and 97.3%, depending on the FCS evaluated in the field. Performance at Rated Value for electrical efficiency (PRVeff) can be defined as the quotient of the system time operating at or above the rated electric efficiency and the time since commissioning. The PRVeff varies between 5.6% and 31.6%, depending on the FCS field unit evaluated. Performance at Rated Value for electrical power (PRVp) can be defined as the quotient of the system time operating at or above the rated electric power and the time since commissioning. PRVp varies between 6.5% and 16.2%. Performance at Rated Value for electrical efficiency and power (PRVt) can be defined as the quotient of the system time operating at or above both the rated electric efficiency and the electric power output compared to the time since commissioning. PRVt varies between 0.2% and 1.4%. Optimization to determine the manufacturer rating required to achieve PRVt greater than 80% has been performed based on the collected data. For example, for FCS unit 130 to achieve a PRVt of 95%, it would have to be down-rated to an electrical power output of 3.2 kWe and an electrical efficiency of 29%.The use of PRV as an assessment metric for FCSs has been developed and reported for the first time in this paper. For FCS Unit 130, a 20% decline in electric power output was observed from approximately 5 kWe to 4 kWe over a 1,500 hour period between Dec. 14th 2011 and Feb. 14th 2012.

Author(s):  
Heather E. Dillon ◽  
Whitney G. Colella

Pacific Northwest National Laboratory (PNNL) is working with industry to independently monitor up to fifteen distinct 5 kilowatt-electric (kWe) combined heat and power (CHP) high temperature (HT) proton exchange membrane (PEM) fuel cell systems (FCSs) installed in light commercial buildings. This research paper discusses an evaluation of the first six months of measured performance data acquired at a one-second sampling rate from real-time monitoring equipment attached to the FCSs at building sites. Engineering performance parameters are independently evaluated. Based on an analysis of the first few months of measured operating data, FCS performance is consistent with manufacturer-stated performance. Initial data indicate that the FCSs have relatively stable performance and a long term average production of about 4.57 kWe of power. This value is consistent with, but slightly below, the manufacturer’s stated rated electric power output of 5 kWe. The measured system net electric efficiency has averaged 33.7%, based on the higher heating value (HHV) of natural gas fuel. This value, also, is consistent with, but slightly below, the manufacturer’s stated rated electric efficiency of 36%. The FCSs provide low-grade hot water to the building at a measured average temperature of about 48.4°C, lower than the manufacturer’s stated maximum hot water delivery temperature of 65°C. The uptime of the systems is also evaluated. System availability can be defined as the quotient of total operating time compared to time since commissioning. The average values for system availability vary between 96.1 and 97.3%, depending on the FCS evaluated in the field. Performance at Rated Value for electrical efficiency (PRVeff) can be defined as the quotient of the system time operating at or above the rated electric efficiency and the time since commissioning. The PRVeff varies between 5.6% and 31.6%, depending on the FCS field unit evaluated. Performance at Rated Value for electrical power (PRVp) can be defined as the quotient of the system time operating at or above the rated electric power and the time since commissioning. PRVp varies between 6.5% and 16.2%. Performance at Rated Value for electrical efficiency and power (PRVt) can be defined as the quotient of the system time operating at or above both the rated electric efficiency and the electric power output compared to the time since commissioning. PRVt varies between 0.2% and 1.4%. Optimization to determine the manufacturer rating required to achieve PRVt greater than 80% has been performed based on the collected data. For example, for FCS unit 130 to achieve a PRVt of 95%, it would have to be down-rated to an electrical power output of 3.2 kWe and an electrical efficiency of 29%.The use of PRV as an assessment metric for FCSs has been developed and reported for the first time in this paper. For FCS Unit 130, a 20% decline in electric power output was observed from approximately 5 kWe to 4 kWe over a 1,500 hour period between Dec. 14th 2011 and Feb. 14th 2012.


2015 ◽  
Vol 12 (3) ◽  
Author(s):  
Heather E. Dillon ◽  
Whitney G. Colella

Pacific Northwest National Laboratory (PNNL) is working with industry to independently monitor up to 15 distinct 5 kW-electric (kWe) combined heat and power (CHP) high temperature (HT) proton exchange membrane (PEM) fuel cell systems (FCSs) installed in light commercial buildings. This research paper discusses an evaluation of the first six months of measured performance data acquired at a 1 s sampling rate from real-time monitoring equipment attached to the FCSs at building sites. Engineering performance parameters are independently evaluated. Based on an analysis of the first few months of measured operating data, FCS performance is consistent with manufacturer-stated performance. Initial data indicate that the FCSs have relatively stable performance and a long-term average production of about 4.57 kWe of power. This value is consistent with, but slightly below, the manufacturer's stated rated electric power output of 5 kWe. The measured system net electric efficiency has averaged 33.7%, based on the higher heating value (HHV) of natural gas fuel. This value, also, is consistent with, but slightly below, the manufacturer's stated rated electric efficiency of 36%. The FCSs provide low-grade hot water to the building at a measured average temperature of about 48.4 °C, lower than the manufacturer's stated maximum hot water delivery temperature of 65 °C. The uptime of the systems is also evaluated. System availability can be defined as the quotient of total operating time compared to time since commissioning. The average values for system availability vary between 96.1 and 97.3%, depending on the FCS evaluated in the field. Performance at rated value for electrical efficiency (PRVeff) can be defined as the quotient of the system time operating at or above the rated electric efficiency and the time since commissioning. The PRVeff varies between 5.6% and 31.6%, depending on the FCS field unit evaluated. Performance at rated value for electrical power (PRVp) can be defined as the quotient of the system time operating at or above the rated electric power and the time since commissioning. PRVp varies between 6.5% and 16.2%. Performance at rated value for electrical efficiency and power (PRVt) can be defined as the quotient of the system time operating at or above both the rated electric efficiency and the electric power output compared to the time since commissioning. PRVt varies between 0.2% and 1.4%. Optimization to determine the manufacturer rating required to achieve PRVt greater than 80% has been performed based on the collected data. For example, for FCS Unit 130 to achieve a PRVt of 95%, it would have to be down-rated to an electrical power output of 3.2 kWe and an electrical efficiency of 29%. The use of PRV as an assessment metric for FCSs has been developed and reported for the first time in this paper. For FCS Unit 130, a maximum decline in electric power output of approximately 18% was observed over a 500 h period in Jan. 2012.


2018 ◽  
Vol 171 ◽  
pp. 02002
Author(s):  
Elie Karam ◽  
Patrick Moukarzel ◽  
Maya Chamoun ◽  
Charbel Habchi ◽  
Charbel Bou-Mosleh

Due to global warming and the high toxic gas emissions of traditional power generation methods, renewable energy has become a very active topic in many applications. This study focuses on one versatile type of solar energy: Hybrid Photovoltaic Thermal System (hybrid PV/T). Hybrid PV/T combines both PV and thermal application and by doing this the efficiency of the system will increase by taking advantage of the temperature loss from PV module. The solar radiation and heat will be harnessed to deliver electricity and hot water simultaneously. In the present study a solar system is designed to recycle the heat and improve the temperature loss from PV module in order to supply both electricity and domestic hot water. The project was tested twice in Zouk Mosbeh - Lebanon; on May 18, 2016, and June 7, 2016. The average electrical efficiency was around 11.5% with an average electrical power output of 174.22 W, while with cooling, the average electrical efficiency reaches 11% with a power output of 200 W. The temperature increases by about 7 degrees Celsius from the inlet. The 1D conduction model is also performed in order to design the hybrid PV/T system.


INSIST ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 81
Author(s):  
Adhy Prayitno ◽  
Muhammad Irvan ◽  
Sigit Nurharsanto ◽  
Wahyu Fajar Yantoa

Observations and measurements have been conducted towards a solar panel electric power output that is utilized by a solar tracking system. The electrical power output depends on the position of the sun and time and the direction of the panel surface against the angle of the incident light. For power optimization, the solar panel surface should always be directed perpendicular to the direction of the sunlight falling to the surface of the panel. The application of the solar tracking system controlled by a micro controller gives the expected results. The electrical power output of a static solar panel mounted on a fixed position becomes the benchmark of the output electric power value in this study. The measurement results of the electric power output of the solar panel with sun tracking system shows a significant increase in sunny weather conditions.The average increase of that is about 57.3%.Keywords: LDR, micro controller, optimal power output, performance improvment, sun tracking,


Author(s):  
Marina Montero Carrero ◽  
Ward De Paepe ◽  
Jan Magnusson ◽  
Alessandro Parente ◽  
Svend Bram ◽  
...  

Despite the potential of micro Gas Turbines (mGTs) for Combined Heat and Power (CHP), this technology still poses limitations that curb its widespread adoption, especially for applications with a variable heat demand. In fact, whenever the user heat demand is low, mGTs are generally shut down. Otherwise, the high temperature exhaust gases have to be blown off and the resulting electrical efficiency is not high enough to sustain a profitable operation. If, instead of released, the heat in the exhaust gases is re-inserted in the cycle — by injecting hot water and transforming the mGT into a micro Humid Air Turbine (mHAT) — the electrical efficiency can be increased during periods of reduced heat demand, thus improving the economics of the technology. Although the enhanced performance of the mHAT cycle has been thoroughly investigated from a numerical point of view, results regarding the experimental behaviour of this technology remain scarce. In this paper, we present the experimental characterisation of the mHAT located at the Vrije Universiteit Brussel (VUB): based on the T100 mGT and equipped with a spray saturation tower. These are the first experimental results of such an engine working at nominal load with water injection. In addition, the control system of the unit has been modified so that it can operate either at constant electrical power output (the default setting) or at constant rotational speed. The latter option allowed to better assess the effect of water injection. Eperimental results demonstrate the patent benefits of water injection on mGT performance: at fixed rotational speed, the power output of the mHAT increases by more than 30%while the fuel consumption rises only by 11%. Overall, the electrical efficiency in wet operation increases by up to 4.2% absolute points. Future work will involve further optimising the current facility to reduce pressure losses in the air and water circuits. In addition, we will carry out transient simulations and experiments in order to further characterise the facility.


Author(s):  
Fatemeh Goodarzvand-Chegini ◽  
Mohammdreza Habibi ◽  
Saeed Rakhsha ◽  
Leila Samiee ◽  
Meisam Amini ◽  
...  

Background: The purpose of this research is to study the solutions for improving the efficiency of a micro combined heat and power (m-CHP) system based on OHVG (OverHead Valve Gas fueled) engine. Method: In this regard, the effects of valve timing and changing the camshaft on the power and fuel consumption of the engine have been numerically and experimentally investigated. The tests have been performed for engine speed range from 1000 rpm to 3500 rpm, while the engine's fuel was natural gas. The numerical results are found to be in good agreement with experimental ones. The effect of changing the valve timing and camshaft on the performance of the m-CHP has been investigated through the experiments in the test room. The engine speed was 1500 rpm; output hot water was fixed at 55oC; and output electrical power varies from 8 kW to 13 kW in the experiments. Results & Conclusion: The experimental results of the engine test indicate that, by changing the camshaft for full load operation and speed 1500 rpm, engine torque and volumetric efficiency improved by 7.2% and 6.0%, respectively, and fuel consumption decreased by 0.8%. According to the results, the best point for the performance of m-CHP is close to the full load of the electrical power because by increasing the electrical load, electrical efficiency increases from about 25.9% to 32.3%, while the thermal efficiency decreases from about 61.9% to 56.1%.


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 787
Author(s):  
Yan Zhang ◽  
Quan Lyu ◽  
Yang Li ◽  
Na Zhang ◽  
Lijun Zheng ◽  
...  

The issue of real-time deep down-regulation ancillary service has received increasing attention in the Northeast of China. Participation of combined heat and power plants with multitype units and flexible heating devices in the market is investigated. This paper establishes a model of feasible operating region and the coal consumption function for the combined heat and power plant. An internal optimal dispatch model and the minimum overall electric power output model for the plant satisfying a given heat load are presented. Furthermore, the models of total cost for down-regulation and average cost for deep down-regulation in two levels are established. These models are validated based on the realistic data of the plant in the Northeast of China. In case studies, the influence factors and change rules of the minimum electric power output, the total cost, and the average cost of plants are analyzed.


Author(s):  
Mark W. Davis ◽  
Michael W. Ellis ◽  
Brian P. Dougherty ◽  
A. Hunter Fanney

The National Institute of Standards and Technology (NIST), in conjunction with Virginia Tech, has developed a rating methodology for residential-scale stationary fuel cell systems. The methodology predicts the cumulative electrical production, thermal energy delivery, and fuel consumption on an annual basis. The annual performance is estimated by representing the entire year of climate and load data into representative winter, spring/fall, and summer days for six different U.S. climatic zones. It prescribes a minimal number of steady state and simulated use tests, which provide the necessary performance data for the calculation procedure that predicts the annual performance. The procedure accounts for the changes in performance resulting from changes in ambient temperature, electrical load, and, if the unit provides thermal as well as electrical power, thermal load. The rating methodology addresses four different types of fuel cell systems: grid-independent electrical load following, grid-connected constant power, grid-connected thermal load following, and grid-connected water heating. This paper will describe a partial validation of the rating methodology for a grid-connected thermal load following fuel cell system. The rating methodology was validated using measured data from tests that subjected the fuel cell system to domestic hot water and space heating thermal loads for each of the three representative days. The simplification of a full year’s load and climate data into three representative days was then validated by comparing the rating methodology predictions with the prediction of each hour over the full year in each of the six cities.


2018 ◽  
Vol 8 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Takatoshi Hayashi ◽  
Tomoya Nagayama ◽  
Tadashi Tanaka ◽  
Yoshitaka Inui

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