Impacts of Balancing Valves on Pump Energy and Control Performance in Variable Water Flow Systems

2005 ◽  
Vol 128 (3) ◽  
pp. 414-417 ◽  
Author(s):  
B. Zheng ◽  
M. Liu
Keyword(s):  
Water Flow ◽  
Pump Energy ◽  
System Control ◽  
Control Performance ◽  
Reduced Pressure ◽  
Control Valves ◽  
Initial Cost ◽  
Partial Load ◽  
Flow Systems ◽  
Variable Water

There is no common agreement on the use of balance valves in the most popular variable water flow systems. A comprehensive theoretical analysis has been conducted to investigate the impacts of balance valves on initial cost, pump operation power, and system control performance. The investigation finds that eliminating balance valves can (i) reduce by 20–40% pump energy consumption in a typical variable flow water system, (ii) reduce the maximum pressure drop across control valves, and (iii) improve pump efficiency at most partial load conditions. The reduced pressure drops across control valves improve system control performance and may allow selecting some control valves at lower close-off pressures. Consequently, eliminating balancing valves can also potentially reduce system initial cost.

Impacts of Balance Valves on Pump Energy and Control Performance in Variable Water Flow Systems

Solar Energy ◽  
2004 ◽  
Author(s):  
B. Zheng ◽  
M. Liu
Keyword(s):  
Pressure Drop ◽  
Water Flow ◽  
Pump Energy ◽  
System Control ◽  
Control Performance ◽  
Reduced Pressure ◽  
Control Valves ◽  
Partial Load ◽  
Flow Systems ◽  
Variable Water

There is no common agreement on the use of balance valves in the most popular variable water flow systems. A comprehensive theoretical analysis has been conducted to investigate the impacts of balance valves on initial cost, pump operation power, and system control performance. The investigation finds that eliminating balance valves can (1) reduce 20% to 40% pump energy consumption in a typical variable flow water system; (2) reduce the maximum pressure drop across control valves; and (3) improve pump efficiency at most partial load conditions. The reduced pressure drop across control valves improve system control performance and may allow selecting some of the control valves at lower close-off pressure. Consequently, eliminating balancing valves can also potential reduce system initial costs.

scholarly journals Variable flow and optimization of chiller loading effect on energy saving for screw vapor compression-single effect absorption hybrid chiller plant in hospital mechanical room ‒ case study: Tehran heart hospital

2021 ◽  
Vol 22 ◽  
pp. 9
Author(s):  
Ronald Boghosian ◽  
Mostafa Mafi ◽  
Mohammad Hassan Panjeshahi ◽  
Abtin Ataei
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Water Flow ◽  
Flow System ◽  
Vapor Compression ◽  
Absorption Chillers ◽  
Partial Load ◽  
Energy Consuming ◽  
Single Effect ◽  
Variable Water

Chiller plants are the most energy consuming system during summer season in residential, commercial and hospital buildings. The highly variable cooling demand of the buildings connected to a hybrid chiller plant included absorption and vapor compression chillers to achieve higher energy efficiencies is one of the important issues. Cooling load sharing strategies and apply the variable water flow system in chiller plant have a significant impact on energy consumption and consequently with more productivity and environmentally protected. This paper examines the behavior and pattern of energy consumption in a hybrid chiller plant that includes a combination of two air-cooled screw vapor compression and three single effect absorption chillers. In order to properly understand the pattern of energy consumption, an existing mechanical room in a hospital in Tehran has been studied for five months, and its energy consumption has been compared with the optimized model. The results indicate that the sequence of the chiller function and the way in which they are placed in the circuit during a partial load, is in highest importance in view point of energy saving also by Applying of variable water flow system for optimized chiller loading the more energy saving is achieved for hybrid absorption and vapor compression chiller plant.

Optimizing the performance of hemispheric solar still using nano-ZnO with cooling the glassy cover at a variable water flow rate

2021 ◽  
Author(s):  
Mohammed El Hadi Attia ◽  
Abd Elnaby Kabeel ◽  
S. A. El-Agouz ◽  
El Mir Mabrouk Lassaad ◽  
Ravishankar Sathyamurthy ◽  
...  
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Solar Still ◽  
Nano Zno ◽  
Variable Water

Robust BackStepping Control Based DRNN for Flight Simulator

2010 ◽  
Vol 139-141 ◽  
pp. 1708-1713 ◽  
Author(s):  
Dong Kai Shen ◽  
Jing Jing Wang ◽  
Zheng Hua Liu
Keyword(s):  
High Performance ◽  
Design Procedure ◽  
Backstepping Control ◽  
Flight Simulator ◽  
System Control ◽  
Control Performance ◽  
External Disturbances ◽  
Motion Simulator ◽  
Backstepping Controller ◽  
Simulation Results

Flight motion simulator is one kind of servo system with uncertainties and nonlinearities. To acquire higher frequency response and good robustness for the flight simulator, we present a Backstepping controller based on a Diagonal Recurrent Neural Network (DRNN) to work out this problem. For one thing, the design procedure of the robust Backstepping controller is described. Subsequently, the principle and the design steps of DRNN are analyzed and expatiated respectively. In the end, simulation results on the flight motion simulator show that robust backstepping control based on DRNN can compensate for external disturbances and enhance robustness of the system control performance. Therefore both robustness and high performance of the flight motion simulator are achieved.

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