Investigate the Potential Use of Absorption Chiller for Waste Heat Recovery of Data Centre; Case Study of Earth Ranger Centre

10.32920/ryerson.14644590.v1 ◽

2021 ◽

Author(s):

Romina Kaveh

Keyword(s):

Energy Demand ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Heat Removal ◽

High Energy ◽

Data Centre ◽

Absorption Chillers ◽

Exhaust Heat ◽

Data Centres

Data centres are great contributors to global warming due to their high energy consumption. The same amount of energy being used in data centres to run the servers is required for cooling to prevent any damage as the result of overheating of the equipment. Reusing the exhaust heat for cooling purposes reduce energy demand for cooling and heat removal systems. This research proposal has focused on waste heat recovery of data centres located in Woodbridge, Ontario by using absorption chillers. A mathematical model was developed to analyze the performance of the system based on the temperature of the generator and absorber in Simulink/MATLAB. It is concluded that the COP of the system improves with the increase of the generator temperature and the decrease of the absorber temperature. Ultimately, a secondary energy source is required along with the rejected heat from the data centre to support the cooling load.

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Optimization of Supercritical CO2 Brayton Cycle for Simple Cycle Gas Turbines Exhaust Heat Recovery Using Genetic Algorithm

Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy ◽

10.1115/gt2017-63696 ◽

2017 ◽

Author(s):

Akshay Khadse ◽

Lauren Blanchette ◽

Jayanta Kapat ◽

Subith Vasu ◽

Kareem Ahmed

Keyword(s):

Genetic Algorithm ◽

Mass Flow Rate ◽

Flow Rate ◽

Supercritical Co2 ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Brayton Cycle ◽

Exhaust Heat ◽

Exhaust Heat Recovery

For the application of waste heat recovery (WHR), supercritical CO2 (S-CO2) Brayton power cycles offer significant suitable advantages such as compactness, low capital cost and applicable to a broad range of heat source temperatures. The current study is focused on thermodynamic modelling and optimization of Recuperated (RC) and Recuperated Recompression (RRC) S-CO2 Brayton cycles for exhaust heat recovery from a next generation heavy duty simple cycle gas turbine using a genetic algorithm. The Genetic Algorithm (GA) is mainly based on bio-inspired operators such as crossover, mutation and selection. This non-gradient based algorithm yields a simultaneous optimization of key S-CO2 Brayton cycle decision variables such as turbine inlet temperature, pinch point temperature difference, compressor pressure ratio. It also outputs optimized mass flow rate of CO2 for the fixed mass flow rate and temperature of the exhaust gas. The main goal of the optimization is to maximize power out of the exhaust stream which makes it single objective optimization. The optimization is based on thermodynamic analysis with suitable practical assumptions which can be varied according to the need of user. Further the optimal cycle design points are presented for both RC and RRC configurations and comparison of net power output is established for waste heat recovery.

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Waste heat recovery from urban air cooled data centres to increase energy efficiency of district heating networks

Sustainable Cities and Society ◽

10.1016/j.scs.2018.12.012 ◽

2019 ◽

Vol 45 ◽

pp. 522-542 ◽

Cited By ~ 15

Author(s):

Eduard Oró ◽

Paolo Taddeo ◽

Jaume Salom

Keyword(s):

Energy Efficiency ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

District Heating ◽

Urban Air ◽

Increase Energy Efficiency ◽

Data Centres ◽

Heating Networks

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The Potential Danger of Fire in Gas Turbine Heat Exchangers

ASME 1969 Gas Turbine Conference and Products Show ◽

10.1115/69-gt-38 ◽

1969 ◽

Author(s):

C. F. McDonald

Keyword(s):

Heat Exchanger ◽

Gas Turbine ◽

Heat Exchangers ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Engine Operation ◽

Exhaust Heat ◽

The Subject ◽

Gas Turbine Cycle

Increased emphasis is being placed on the regenerative gas turbine cycle, and the utilization of waste heat recovery systems, for improved thermal efficiency. For such systems there are modes of engine operation, where it is possible for a metal fire to occur in the exhaust heat exchanger. This paper is intended as an introduction to the subject, more from an engineering, than metallurgical standpoint, and includes a description of a series of simple tests to acquire an understanding of the problem for a particular application. Some engine operational procedures, and design features, aimed at minimizing the costly and dangerous occurrence of gas turbine heat exchanger fires, are briefly mentioned.

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Thermodynamic Analysis of Supercritical Carbon Dioxide Cycle for Internal Combustion Engine Waste Heat Recovery

Processes ◽

10.3390/pr8020216 ◽

2020 ◽

Vol 8 (2) ◽

pp. 216 ◽

Cited By ~ 1

Author(s):

Wan Yu ◽

Qichao Gong ◽

Dan Gao ◽

Gang Wang ◽

Huashan Su ◽

...

Keyword(s):

Carbon Dioxide ◽

Thermal Efficiency ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Combustion Engine ◽

Recovery Ratio ◽

Split Flow ◽

Exhaust Heat ◽

Exhaust Heat Recovery

Waste heat recovery of the internal combustion engine (ICE) has attracted much attention, and the supercritical carbon dioxide (S-CO2) cycle was considered as a promising technology. In this paper, a comparison of four S-CO2 cycles for waste heat recovery from the ICE was presented. Improving the exhaust heat recovery ratio and cycle thermal efficiency were significant to the net output power. A discussion about four different cycles with different design parameters was conducted, along with a thermodynamic performance. The results showed that choosing an appropriate inlet pressure of the compressor could achieve the maximum exhaust heat recovery ratio, and the pressure increased with the rising of the turbine inlet pressure and compressor inlet temperature. The maximum exhaust heat recovery ratio for recuperation and pre-compression of the S-CO2 cycle were achieved at 7.65 Mpa and 5.8 MPa, respectively. For the split-flow recompression cycle, thermal efficiency first increased with the increasing of the split ratio (SR), then decreased with a further increase of the SR, but the exhaust heat recovery ratio showed a sustained downward trend with the increase of the SR. For the split-flow expansion cycle, the optimal SR was 0.43 when the thermal efficiency and exhaust heat recovery ratio achieved the maximum. The highest recovery ratio was 24.75% for the split-flow expansion cycle when the total output power, which is the sum of the ICE power output and turbine mechanical power output, increased 15.3%. The thermal performance of the split-flow expansion cycle was the best compared to the other three cycles.

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Organic Rankine Cycle for Waste Heat Recovery in a Hybrid Vehicle

Volume 4: 12th International Conference on Advanced Vehicle and Tire Technologies; 4th International Conference on Micro- and Nanosystems ◽

10.1115/detc2010-28816 ◽

2010 ◽

Cited By ~ 1

Author(s):

Quazi E. Hussain ◽

David R. Brigham

Keyword(s):

Fuel Economy ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Operating Conditions ◽

Working Fluid ◽

Drive Cycle ◽

Exhaust Heat

The Rankine cycle is used commercially to generate power in stationary power plants using water as the working fluid. For waste heat recovery applications, where the temperature is lower, water is typically replaced by a carefully selected organic fluid. This work is based on using the waste heat in an automobile to generate electricity using the Organic Rankine cycle (ORC) with R245fa (1, 1, 1, 3, 3 penta-fluoropropane) as the working fluid. The electricity thus generated can be used to drive the accessory load or charge the battery which in any case helps improve the fuel economy. A simple transient numerical model has been developed that is capable of capturing the main effects of this cycle. Results show that exhaust heat alone can generate enough electricity that is capable of bringing about an improvement to the fuel economy under transient drive cycle conditions. Power output during EPA Highway drive cycle is much higher than EPA City due to higher exhaust mass flow rate and temperature. Time needed to reach operating conditions or in other words, the warm-up time plays an important role in the overall drive cycle output. Performance is found to improve significantly when coolant waste heat is used in conjunction with the residual exhaust heat to pre-heat the liquid. A sizing study is also performed to keep the cost, weight, and packaging requirement down without sacrificing too much power. With careful selection of heat exchanger design parameters, it has been demonstrated that the backpressure on the engine can be actually lowered by cooling off the exhaust gas. This lower backpressure will further boost the fuel economy gained by the electricity produced by the Rankine bottoming cycle.

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Heat Transfer and Pressure Drop Investigations of the Compact Exhaust Heat Exchanger With Twisted Tape Inserts for Automotive Waste Heat Utilization

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4048672 ◽

2020 ◽

Vol 13 (4) ◽

Author(s):

Dhruv Raj Karana ◽

Rashmi Rekha Sahoo

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Internal Heat ◽

Decisive Role ◽

Twisted Tape ◽

Twisted Tapes ◽

Exhaust Heat

Abstract Thermoelectric-based waste heat recovery is a competent technique to reduce the exhaust emissions and fuel consumption of automobiles. Thermal and hydraulic characteristics of the exhaust heat exchanger plays a decisive role in the extent of waste heat recovery from the exhaust gas. In this study, the exhaust heat exchanger having twisted tape inserts is proposed to increase the internal heat transfer coefficient. The dimensionless Nusselt number and friction factor were evaluated experimentally for different designs of the twisted tapes. The experiments were performed for the Reynolds number in the range 2300–25000. The considered geometric parameters of the twisted rib explored were the pitch fraction, twist fraction, and slope. The obtained results were compared to reveal the best feasible design of the twisted tape. The maximum net thermohydraulic efficiency factor achieved for the system in the present analysis is 1.93. With the use of twisted tapes, the area of the exhaust heat exchanger can be greatly reduced for the same power output as flat geometry. This would help for the integration of the waste heat recovery with the engine, where the space available is very limited.

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An Innovative Heating Energy System Planning and Design: Case of Yinchuan City

ASME 2013 7th International Conference on Energy Sustainability ◽

10.1115/es2013-18399 ◽

2013 ◽

Author(s):

Zhonghai Zheng ◽

Lin Fu ◽

Zi Wu ◽

Xiling Zhao ◽

Yanting Wu

Keyword(s):

Energy Efficiency ◽

Heat Exchange ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Economic Cost ◽

Heating System ◽

High Energy ◽

Large Temperature ◽

Energy Structure

The current heating system in Yinchuan city, the capital of the Ningxia Autonomous Region in northwest China, is investigated and analyzed. Lacking an integrated planning, the heating systems have developed with low energy efficiency, high environment emission and economic cost. The choice of heating energy structure vary between coal and gas, the heating modes including gas-fired CHP, coal-fired CHP, gas-fired boiler and coal-fired boiler are facing challenges. In this paper, several innovative planning scenarios are proposed to achieve high energy efficiency, low environment emission and reasonable economic cost. In the heating schemes, three innovative technologies are designed. The first technology is waste heat recovery based on the Co-generation-based absorption heat-exchange (Co-ah) cycle. The waste heat can be both from circulating water or flue gas in CHP heating system and the industrial waste heat recovery. The second technology is the heating network with large temperature difference. The third technology is the gas distributed peak-shaving, gas-driven absorption heat-exchange in the substation.

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