Thermodynamic Analysis of Wave Rotor Refrigerators

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Dai Yuqiang ◽  
Zou Jiupeng ◽  
Zhu Che ◽  
Liu Peiqi ◽  
Zhao Jiaquan ◽  
...  
Keyword(s):  
Thermodynamic Analysis ◽  
Assessment Model ◽  
Refrigeration System ◽  
Analysis Model ◽  
Wave Rotor ◽  
Contributing Factors ◽  
Compression Efficiency ◽  
Wave Rotors ◽  
Flow Device ◽  
Working Procedure

As a novel generation of rotary thermal separators, a wave rotor refrigerator (WRR) is an unsteady flow device used for refrigeration in whose passages pressured streams directly contact and exchange the energy due to the movement of pressure waves. In this work, the working procedure and wave diagram of WRR are investigated thoroughly. Based on this, a novel WRR thermodynamic analysis model has been established and validated by experiments. This performance assessment model shows the main contributing factors of expansion and compression processes. A particular analysis of WRR refrigeration system has revealed that expansion efficiency can be adversely affected by excessive high compression efficiency, which means that particular emphasis should be laid on wave rotors for supercharging or refrigeration.

Performance Benefits of R718 Turbo-Compression Cycle Using 3-Port Condensing Wave Rotors

2004 ◽  
Author(s):  
Amir A. Kharazi ◽  
Pezhman Akbari ◽  
Norbert Mu¨ller
Keyword(s):  
Performance Enhancement ◽  
The Novel ◽  
Wave Rotor ◽  
Flash Evaporation ◽  
Pressurized Water ◽  
Wave Rotors ◽  
Compression Cycle ◽  
Performance Map ◽  
Wave Compression ◽  
Novel Concept

A number of technical challenges have often hindered the economical application of refrigeration cycles using water (R718) as refrigerant. The novel concept of condensing wave rotor provides a solution for performance improvement of R718 refrigeration cycles. The wave rotor implementation can increase efficiency and reduce the size and cost of R718 units. The condensing wave rotor employs pressurized water to pressurize, desuperheat, and condense the refrigerant vapor — all in one dynamic process. In this study, the underlying phenomena of flash evaporation, shock wave compression, desuperheating, and condensation inside the wave rotor channels are described in a wave and phase-change diagram. A computer program based on a thermodynamic model is generated to evaluate the performance of R718 baseline and wave-rotor-enhanced cycles. The detailed thermodynamic approach for the baseline and the modified cycles is described. The effect of some key parameters on the performance enhancement is demonstrated as an aid for optimization. A generated performance map summarizes the findings.

Defining the Thermodynamic Efficiency in a Wave Rotor

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Shining Chan ◽  
Huoxing Liu ◽  
Fei Xing
Keyword(s):  
Gas Turbine ◽  
Control Volume ◽  
Thermodynamic Efficiency ◽  
Wave Rotor ◽  
Wave Rotors ◽  
Compression And Expansion ◽  
Efficiency Estimation ◽  
Parametric Analyses ◽  
Control Volumes ◽  
Thermodynamic Processes

A wave rotor enhances the performance of a gas turbine with its internal compression and expansion, yet the thermodynamic efficiency estimation has been troubling because the efficiency definition is unclear. This paper put forward three new thermodynamic efficiency definitions to overcome the trouble: the adiabatic efficiency, the weighted-pressure mixed efficiency, and the pressure pre-equilibrated efficiency. They were all derived from multistream control volumes. As a consequence, they could correct the efficiency values and make the values for compression and expansion independent. Moreover, the latter two incorporated new models of pre-equilibration inside a control volume, and modified the hypothetical “ideal” thermodynamic processes. Parametric analyses based on practical wave rotor data demonstrated that the trends of those efficiency values reflected the energy losses in wave rotors. Essentially, different thermodynamic efficiency definitions indicated different ideal thermal cycle that an optimal wave rotor can provide for a gas turbine, and they were recommended to application based on that essence.

scholarly journals Operational Risk Assessment of Electric-Gas Integrated Energy Systems Considering N-1 Accidents

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1208 ◽  
Author(s):  
Hua Liu ◽  
Yong Li ◽  
Yijia Cao ◽  
Zilong Zeng ◽  
Denis Sidorov
Keyword(s):  
Risk Assessment ◽  
Energy System ◽  
Assessment System ◽  
Coupled Systems ◽  
Assessment Model ◽  
Analysis Model ◽  
Integrated Energy Systems ◽  
Integrated Energy System ◽  
Operation Status ◽  
The Mathematical Model

The reliability analysis method and risk assessment model for the traditional single network no longer meet the requirements of the risk analysis of coupled systems. This paper establishes a risk assessment system of electric-gas integrated energy system (EGIES) considering the risk security of components. According to the mathematical model of each component, the EGIES steady state analysis model considering the operation constraints is established to analyze the operation status of each component. Then the EGIES component accident set is established to simulate the accident consequences caused by the failure of each component to EGIES. Furthermore, EGIES risk assessment system is constructed to identify the vulnerability of EGIES components. Finally, the risk assessment of IEEE14-NG15 system is carried out. The simulation results verify the effectiveness of the proposed method.

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