scholarly journals Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors

Inventions ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 15 ◽  
Author(s):  
Zine Aidoun ◽  
Khaled Ameur ◽  
Mehdi Falsafioon ◽  
Messaoud Badache
Keyword(s):  
Energy Use ◽  
Single Phase ◽  
Heat Pumps ◽  
Compressible Fluids ◽  
Thermally Activated ◽  
Temperature Heat ◽  
Potential Applications ◽  
Experimental Approaches ◽  
And Performance ◽  
Efficient Energy Use

Ejectors used in refrigeration systems as entrainment and compression components or expanders, alone or in combination with other equipment devices, have gained renewed interest from the scientific community as a means of low temperature heat recovery and more efficient energy use. This paper summarizes the main findings and trends, in the area of heat-driven ejectors and ejector-based machines, using low boiling point working fluids, which were reported in the literature for a number of promising applications. An overall view of such systems is provided by discussing the ejector physics principles, as well as a review of the main developments in ejectors over the last few years. Recent achievements on thermally activated ejectors for single-phase compressible fluids are the main focus in this part of the review. Aspects related to their design, operation, theoretical and experimental approaches employed, analysis of the complex interacting phenomena taking place within the device, and performance are highlighted. Conventional and improved ejector refrigeration cycles are discussed. Some cycles of interest employing ejectors alone or boosted combinations are presented and their potential applications are indicated.

scholarly journals Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 2: Two-Phase Ejectors

Inventions ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 16 ◽  
Author(s):  
Zine Aidoun ◽  
Khaled Ameur ◽  
Mehdi Falsafioon ◽  
Messaoud Badache
Keyword(s):  
Heat Pumps ◽  
Operating Conditions ◽  
Industrial Processes ◽  
Experimental Investigations ◽  
Mixing Enhancement ◽  
Data Generation ◽  
Two Phase ◽  
Wide Range ◽  
Potential Applications ◽  
And Performance

Two-phase ejectors play a major role as refrigerant expansion devices in vapor compression systems and can find potential applications in many other industrial processes. As a result, they have become a focus of attention for the last few decades from the scientific community, not only for the expansion work recovery in a wide range of refrigeration and heat pump cycles but also in industrial processes as entrainment and mixing enhancement agents. This review provides relevant findings and trends, characterizing the design, operation and performance of the two-phase ejector as a component. Effects of geometry, operating conditions and the main developments in terms of theoretical and experimental approaches, rating methods and applications are discussed in detail. Ejector expansion refrigeration cycles (EERC) as well as the related theoretical and experimental research are reported. New and other relevant cycle combinations proposed in the recent literature are organized under theoretical and experimental headings by refrigerant types and/or by chronology whenever appropriate and systematically commented. This review brings out the fact that theoretical ejector and cycle studies outnumber experimental investigations and data generation. More emerging numerical studies of two-phase ejectors are a positive step, which has to be further supported by more validation work.

Stirling Machines

1989 ◽  
Vol 7 (4) ◽  
pp. 262-270
Author(s):  
Peter Tailer
Keyword(s):  
Electricity Generation ◽  
Human Heart ◽  
Energy Use ◽  
Heat Pumps ◽  
Space Vehicles ◽  
Development Programs ◽  
Efficient Energy ◽  
Stirling Engines ◽  
Energy Conversion Devices ◽  
Efficient Energy Use

The operation of a basic Stirling engine is explained along with the theoretical advantages of these engines compared to other energy conversion devices. Some recent research and development programs are briefly described which have produced or evaluated Stirling engines for automobiles, submarines, space vehicles, and solar thermal electricity generation. Smaller engines include one designed to power an artificial human heart. Stirling coolers, heat pumps, and other devices may contribute to more efficient energy use.

scholarly journals Heat Pump Bridge Analysis Using the Modified Energy Transfer Diagram

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 137
Author(s):  
Florian Schlosser ◽  
Heinrich Wiebe ◽  
Timothy G. Walmsley ◽  
Martin J. Atkins ◽  
Michael R. W. Walmsley ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Heat Pump ◽  
Heat Recovery ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Combined Application ◽  
Recovery Potential ◽  
Composite Curve ◽  
And Performance ◽  
The Individual

Heat pumps are the key technology to decarbonise thermal processes by upgrading industrial surplus heat using renewable electricity. Existing insight-based integration methods refer to the idealised Grand Composite Curve requiring the full exploitation of heat recovery potential but leave the question of how to deal with technical or economic limitations unanswered. In this work, a novel Heat Pump Bridge Analysis (HPBA) is introduced for practically targeting technical and economic heat pump potential by applying Coefficient of Performance curves into the Modified Energy Transfer Diagram (METD). Removing cross-Pinch violations and operating heat exchangers at minimum approach temperatures by combined application of Bridge Analysis increases the heat recovery rate and reduce the temperature lift to be pumped at the same time. The insight-based METD allows the individual matching of heat surpluses and deficits of individual streams with the capabilities and performance of different market-available heat pump concepts. For an illustrative example, the presented modifications based on HPBA increase the economically viable share of the technical heat pump potential from 61% to 79%.

scholarly journals Energy use and retrofitting potential of heat pumps in cold climate hotels

2021 ◽  
Vol 298 ◽  
pp. 126799
Author(s):  
S. Smitt ◽  
I. Tolstorebrov ◽  
P. Gullo ◽  
A. Pardiñas ◽  
A. Hafner
Keyword(s):  
Energy Use ◽  
Heat Pumps ◽  
Cold Climate

scholarly journals Integrated high temperature heat pumps and thermal storage tanks for combined heating and cooling in the industry

2021 ◽  
Vol 189 ◽  
pp. 116731
Author(s):  
Marcel Ulrich Ahrens ◽  
Sverre Stefanussen Foslie ◽  
Ole Marius Moen ◽  
Michael Bantle ◽  
Trygve Magne Eikevik
Keyword(s):  
High Temperature ◽  
Thermal Storage ◽  
Heat Pumps ◽  
Storage Tanks ◽  
Heating And Cooling ◽  
Temperature Heat

scholarly journals Design and Performance Evaluation of a Single-Phase Driven Ultrasonic Motor Using Bending-Bending Vibrations

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 853
Author(s):  
Dongmei Xu ◽  
Wenzhong Yang ◽  
Xuhui Zhang ◽  
Simiao Yu
Keyword(s):  
Single Phase ◽  
Oblique Line ◽  
Ultrasonic Motor ◽  
Vibration Modes ◽  
Bending Vibrations ◽  
Bending Vibration ◽  
Output Performance ◽  
Resonance Frequencies ◽  
And Performance ◽  
Line Trajectory

An ultrasonic motor as a kind of smart material drive actuator has potential in robots, aerocraft, medical operations, etc. The size of the ultrasonic motor and complex circuit limits the further application of ultrasonic motors. In this paper, a single-phase driven ultrasonic motor using Bending-Bending vibrations is proposed, which has advantages in structure miniaturization and circuit simplification. Hybrid bending vibration modes were used, which were excited by only single-phase voltage. The working principle based on an oblique line trajectory is illustrated. The working bending vibration modes and resonance frequencies of the bending vibration modes were calculated by the finite element method to verify the feasibility of the proposed ultrasonic motor. Additionally, the output performance was evaluated by experiment. This paper provides a single-phase driven ultrasonic motor using Bending-Bending vibrations, which has advantages in structure miniaturization and circuit simplification.

scholarly journals Experiment Study on Performance of Air Source Heat Pump

2013 ◽  
Vol 805-806 ◽  
pp. 645-648
Author(s):  
Wei Xiu Shi ◽  
Li Sheng Pan
Keyword(s):  
Heat Pump ◽  
Temperature Difference ◽  
Heat Pumps ◽  
Outlet Temperature ◽  
Exhaust Temperature ◽  
Air Source Heat Pump ◽  
And Performance ◽  
Save Energy ◽  
C 30 ◽  
Set Up

Under the situation of energy crisis, air source heat pumps are paid more attention recently. In order to save energy, the feasibility and performance of air source heat pump are studied by experiment, and variation laws of exhaust temperature, evaporator outlet temperature and outlet presser of compressor were analyzed in this paper. Air source heat pump apparatus were set up and the experiment was during 10°C, 20°C, 30°C and 40°C. The results were as follows: exhaust temperature of compressor increases gradually with the increase of tank temperature, but the temperature difference between exhaust temperature of compressor and tank temperature becomes little; temperature difference in evaporator decreases; Compressor outlet pressure increases obviously.

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