Electricity Generator and Other Research in Key Laboratory of Cryogenics of CAS Wei Dai Technical...
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Transcript of Electricity Generator and Other Research in Key Laboratory of Cryogenics of CAS Wei Dai Technical...
Electricity Generator and Other Research in Key Laboratory of Cryogenics of CAS
Wei Dai
Technical Institute of Physics and Chemistry,
Chinese Academy of Sciences , Beijing , China
Our group
The group members: Prof. Ercang Luo and Wei Dai 5 other staff members >10 graduate students Research Activity: Coolers based on thermoacoustic cycles, down to 20 K
Thermoacoustics engines and generators, from 100We-3kWe, target bigger
Typical Research
300 Hz thermoacoustically-driven pulse tube cooler
Stirling-type pulse tube coolers Thermoacoustic generators ( including free piston Stirling generators)
Tc<80K
Heating
Thermoacoustically-driven pulse tube coolers
High frequency thermoacoustically-driven pulse tube coolers ( 300Hz )
The standing-wave engine The pulse tube cooler
500W heating power , 1W@80K
Traveling wave thermoacoustic engine driving traveling wave thermoacoustic cooler
Heating
Heatingpower 2.1kW, Cooling power 340W@-20℃, 410W@0 , on-going research include high frequency ℃ operation, impedance match, etc
10&20W@80K, relative Carnot efficiency around 20%, >100 Watt under development
High efficiency Stirling-type pulse tube cooler
Thermoacoustic generators
Free piston Stirling generators
Thermoacoustic Stirling heat engine-based generators
Double effect thermoacoustic generators
Free piston Stirling generators
1.Hot heat exchanger 2.Regenerator 3.Ambient heat exchanger 4.Linear motor 5. Mechanical spring 6. Backside volume
7.Expansion space 8.Displacer 9.Compression space 10.Power piston
Free piston Stirling generators
100 We class 1kWe class, ~20% thermal to electric efficiency
Double effects thermoacoustic generators
Engine set with heat exchangers, regenerator and thermal buffer tube
Linear motor with double effect
pistons
Double effects thermoacoustic generators
Best results so far: nearly 2 kWe with 18% thermal to electric efficiency
TASHE loopResonance tube
Linear alternator
Thermoacoustic Stirling heat engine-based generators
System details
Engine Parameters:
17
Feedback tube
Main ambient
HX
regenerator Heaterblock
Thermal buffer
tube
Secondary ambient
HX
Resonancetube
Length (m)
1.55 0.05 0.08 0.06 0.24 0.02 4.45+1.0
Diameter (m)
0.1 0.08-0.3
Dmm
τN/A
KN/mm
Mkg
Rmech
N·s/mLs
mHrΩ
RΩ
60 102 171 0.93 15 264 3.7 60
Linear alternator Parameters:
Numerical Model
18
2
ˆ ˆdpR U
dx
1 3
ˆˆˆ
dUR p R U
dx
1 2xdT
H c cdx
ˆ ˆ 0e eU R jX I
A
2
ˆ ˆ ˆm mR jXU I p
A A
Engine Model Generator Model
Comparison of the model with RC load to measure
output
Computational and experimental data of the TASHE
(4MPa helium,75Hz working frequency, 650 heating temperature )℃19
When it comes to a linear alternator, frequency coupling between the system working frequency (dominated by the engine) and the natural frequency of the linear alternator (dominated by its spring stiffness, moving mass, piston area) is crucial to the system performance.
20
Changing the natural frequency of the linear alternator makes big difference ( adjusting the moving mass)
21
Computational results of power and pressure ratio as a function of the natural frequency of linear alternator (6cm piston diameter, 4.0 MPa helium, 650 oC heating temperature and 15 oC cooling water temperature).
The system stops working in this natural frequency range.
6cm piston
Changing Piston diameter makes big difference
22
23
Changing Piston diameter makes big difference
24
Changing Piston diameter makes big difference
Changing the engine frequency makes big difference (mixing Argon with Helium)
25
Experimental setup
26
TASHE loopLinear alternator
Resonance tube
27
Experimental results
Best results : 1 kWe output with 19% thermal to electric efficiency
Solar-powered version, set up in Shen Zhen, China
28
Thanks for your attention