scholarly journals A Plan for Emergency Shutdown and Reopening for a Consortium of Biobanks

2021 ◽  
Author(s):  
Monika Schmelz ◽  
Micheline Sanderson-November ◽  
Razan Humeida ◽  
Melissa Cloete ◽  
Martha Mims ◽  
...  
Keyword(s):  
Emergency Shutdown

Avoiding Compressor Surge During Emergency Shutdown Hybrid Turbine Systems

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Paolo Pezzini ◽  
David Tucker ◽  
Alberto Traverso
Keyword(s):  
Fuel Cell ◽  
System Analysis ◽  
Risk Mitigation ◽  
Dynamic Effect ◽  
Transient Behavior ◽  
Open Loop ◽  
Department Of Energy ◽  
Mitigation Strategies ◽  
Emergency Shutdown ◽  
Compressor Surge

A new emergency shutdown procedure for a direct-fired fuel cell turbine hybrid power system was evaluated using a hardware-based simulation of an integrated gasifier/fuel cell/turbine hybrid cycle (IGFC), implemented through the Hybrid Performance (Hyper) project at the National Energy Technology Laboratory, U.S. Department of Energy (NETL). The Hyper facility is designed to explore dynamic operation of hybrid systems and quantitatively characterize such transient behavior. It is possible to model, test, and evaluate the effects of different parameters on the design and operation of a gasifier/fuel cell/gas turbine hybrid system and provide a means of quantifying risk mitigation strategies. An open-loop system analysis regarding the dynamic effect of bleed air, cold air bypass, and load bank is presented in order to evaluate the combination of these three main actuators during emergency shutdown. In the previous Hybrid control system architecture, catastrophic compressor failures were observed when the fuel and load bank were cut off during emergency shutdown strategy. Improvements were achieved using a nonlinear fuel valve ramp down when the load bank was not operating. Experiments in load bank operation show compressor surge and stall after emergency shutdown activation. The difficulties in finding an optimal compressor and cathode mass flow for mitigation of surge and stall using these actuators are illustrated.

Analysis of Flow Blockage of a Single Fuel Assembly in the JRR-3 20MW Research Reactor

2018 ◽  
Author(s):  
Yuchuan Guo ◽  
Guanbo Wang ◽  
Dazhi Qian ◽  
Heng Yu ◽  
Bo Hu
Keyword(s):  
Fuel Assembly ◽  
System Analysis ◽  
Research Reactor ◽  
Natural Circulation ◽  
Reactor Core ◽  
Nucleate Boiling ◽  
Regulation System ◽  
Lower Power ◽  
Emergency Shutdown ◽  
Flow Blockage

The case of flow blockage of a single fuel assembly in the JRR-3 20MW open-pool-type research reactor is investigated without taking into account the effect of the power regulation system. The coolant system and multi-channel reactor core are modeled in detail using thermal hydraulic system analysis code RELAP5/MOD3.4. MDNBR (Minimum Departure From Nucleate Boiling Ratio) and the maximum fuel central temperature are investigated to assess the integrity of fuels. The fuel plates in blocked assembly are not damaged until the blockage ratio exceeds 70%. In addition, the mitigative effect of the assumed 18 MW lower power emergency shutdown operation on the accident is also discussed qualitatively. Results indicate that although the assumed lower power emergency shutdown operation cannot avoid the most severe operating condition, it can obviously mitigate the consequences of the accident. The reactor eventually remains in the long-term safe state when natural circulation is established.

Enable emergency shutdown

2019 ◽  
pp. 125-126
Author(s):  
Michael Wiklund ◽  
Kimmy Ansems ◽  
Rachel Aronchick ◽  
Cory Costantino ◽  
Alix Dorfman ◽  
...  
Keyword(s):  
Emergency Shutdown

scholarly journals Development of a condition monitoring system for the refractory lining of induction crucible steelmaking furnaces

Vestnik IGEU ◽  
2019 ◽  
pp. 58-66
Author(s):  
I.Yu. Dolgikh ◽  
M.G. Markov
Keyword(s):  
Monitoring System ◽  
Refractory Lining ◽  
Control Object ◽  
Practical Implementation ◽  
Microprocessor System ◽  
Induction Melting ◽  
Monitoring And Control ◽  
Operation Conditions ◽  
Emergency Shutdown ◽  
Wide Range

A wide range of technological advantages of induction crucible melting furnaces makes their use in various sectors of metallurgical production relevant. However, hard operation conditions of the refractory lining of such furnaces makes it necessary to constantly monitor its condition, with the aim to extend the crucible life and prevent emergencies. Moreover, traditional methods based on the use of a bottom electrode and indication of current leakage to earth do not provide a continuous display of the lining destruction degree and make it possible to register only a critical level that requires an emergency shutdown and emptying of the furnace. This circumstance makes it necessary to develop and implement specialized electrical systems with a monitoring and control system that ensures the determination and visualization of the lining wear level and, if necessary, makes an emergency shutdown of the equipment from the power source. The developed complex is based on a microprocessor system that continuously measures the temperature at the control points at the boundary between the bottom and crucible base layers and compares the obtained values with the settings, which are determined previously on a two-dimensional axisymmetric model of the designed furnace by solving the stationary heat conduction equation at various levels of lining failure. We have developed the structure, scheme, and program for a microprocessor-based monitoring and emergency shutdown system of an induction furnace, as well as a mathematical model of the control object, which allows determining the temperature settings. The reliability of the results is confirmed by the applicability of the models to real objects, and is verified by debugging the microprocessor part in the MPLab-Sim and Proteus programs. The obtained results can be used in the practical implementation of the monitoring system and emergency shutdown of induction melting furnaces, which allows increasing the safety of their operation and extending the lining life due to timely repair.

Nonsteady Operational Behavior of Single-Shaft and Two-Shaft Closed-Cycle Gas Turbines

1978 ◽  
Author(s):  
K. Bammert ◽  
R. Krapp ◽  
U. Reiter
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Closed Cycle ◽  
Dynamic Changes ◽  
Full Load ◽  
Emergency Shutdown ◽  
Reference Plants ◽  
Load Release

The nonsteady operational behavior of single- and two-shaft closed-cycle gas turbines is investigated on the basis of two reference plants. The behavior in case of a full-load release and after emergency shutdown was calculated. It is proved that these disturbances of operation can be mastered in two-shaft plants as well as in single-shaft plants. Furthermore, the stresses caused by dynamic changes in the circuit and to be considered in designing a closed-cycle gas turbine were investigated.

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