BINARY FLUID EJECTOR REFRIGERATING … cycle of the ERS. 7-8-1 – heating and boiling in the vapour...
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THERMODYNAMIC CYCLES OF ERS AND BERS Figure 3. Thermodynamic cycle of the ERS. 7- 8-1 – heating and boiling in the vapour generator; 1-2 – working fluid expansion in the ejector nozzle; 2-4 and 3-4 – working and refrigerant vapour mixing; 4 – 4’ – vapour mixture compression in ejector; 4’-5-6 vapour condensation; 6-6’ - liquid throttling to evaporator; 6-7 liquid fluid feeding to the vapour generator; 6’-3 – refrigerant fluid evaporation in the evaporator. q 3-6’ q 1-7 < 1 q rf q wf = Figure 4. Thermodynamic cycle of the BERS. 1-2 – working fluid heating and evaporation in the vapour generator, 2-3 – working vapour expansion in the nozzle, 3-4 and 5-4 – working vapour and refrigerant vapour mixing in confuser, 4-4’ – mixture compression in the cylindrical mixing chamber, 7-8 working fluid condensation in the fractionating condenser, 6-9 refrigerant fluid condensation, 8-8’ – refrigerant fluid throttling, 8-5 – refrigerant fluid evaporation evaporation, 9-1 – working fluid pumping into the vapour generator. q 5-8’ q 2-1 > 1 q rf q wf = * All data received from REFPROP 9.1 EJECTOR REFRIGERATING SYSTEM 1. New concepts and prior art validation of 50-70% efficiency gain while using the binary fluids in the Ejector Refrigerating Systems (ERS) over the single fluid application; 2. Selection of the binary fluid components to achieve the maximum efficiency of the ERS; 3. Analysis of the binary fluids condensation and separation methods, development of the fractionating condenser, designed for the most absolute components separation. Off-design conditions control and adjustment; 4. Develop an in-house code for ERS parameters calculation and validate the binary ejector geometry profile by the CFD analysis of the mixed fluid flows; 5. Develop a prototype system and demonstrate the Binary Fluid ERS technology at a lab scale, experimental data collection and analysis; 6. Characterization of the Binary Fluid Ejector Refrigerating System in the context of its technical energy savings potential, development status, non- energy benefits, and other factors affecting end-user acceptance along with their ability to compete with the conventional vapor-compression or heat operated adsorption/absorption cooling systems Figure 1. a – the schematic of the single fluid ERS; b – the schematic of the binary fluid ERS (BERS) Figure 2. Schematic diagram of ejector. The main throttling and energy characteristics of ejector is entrainment ratio. The ejector’s geometry significantly influence ejector’s performance. Application of CFD modelling allows to optimize the Binary Ejector geometry to achieve the maximum possible entrainment ratio at set parameters. Such approach makes possible to optimize installation of ejector refrigerating system on a stage of its design. CFD MODELLING OF EJECTOR’S FLOW PART Working fluid q ev /q gen U COP R290/RE170 0.937 0.64 0.60 R600/RE170 0.743 0.66 0.49 R600 0.67 0.51 0.34 RE170 0.767 0.54 0.41 R13T1 0.765 0.44 0.34 R601b 0.615 0.50 0.31 RC318 0.545 0.42 0.23 Results of CFD modelling PERFORMANCE COMPARISON OF ERS AND BERS exp theor comp l U = -1 l where U - entrainment ratio, Q eva – cooling capacity, Q gen – consumed heat, q eva - specific cooling capacity, q gen – specific heat consumed, l exp – work of adiabatic expansion; l comp – work of adiabatic compression; U theor – theoretical entrainment ratio, Z – compression factor, T – temperature, P – pressure, k – adiabatic index, wf and rf – working and refrigerant fluid, gen and eva – vapour generation and evaporation parameter. R wf gen wf gen k -1 wf wf wf k gen gen exp wf rf gen eva Z T P l = 1- k -1 P R rf eva rf eva k -1 rf rf mix k eva cond comp rf rf eva eva Z T P l = -1 k -1 P Figure 5. COP comparisson of Single and Binary Fluid ERS (1 ) rf eva eva gen gen wf r x Q q COP U U Q q r h = = = (0,5 0, 9) COP U U < rf wf r r COP U usually BINARY FLUID EJECTOR REFRIGERATING SYSTEM FOR AIR CONDITIONING IN HUMID ZONES Department of Energy and Environmental Engineering (EEE), Interdisciplinary Graduate School of Engineering Sciences (IGSES), Kyushu University RESEARCH BACKGROUND RESEARCH SUBJECTS AND METHODOLOGY Research subject Methodology 1. Binary fluid components selection. a. Selection based on “tailored” properties (molecular mass, spee d of sound, latent heat of evaporation, compressibility factor, O DP, GWP etc.); b. Definition of the operating parameters. Computer simulation of mixing and separation processes of binary single-phase fluids, validation of fluids properties at t he set parameters. 2. Binary fluid ejector analysis. a. Improvement of the ejector’s calculation algorithm; b. Convergent geometry optimization for shock losses reduction a t the expense of intake flows angle of attack; c. Ejector CFD modelling. Optimization of the ejector’s flow part d esign; Theoretical analysis of the processes in the binary fluid eject or, convergent geometry design for shock losses reduction a nd flow axis alignment. CFD modeling of binary fluid ejector’ s flow part. 3. Theoretical and experimental research of the binary fluid ejector. a. Turbulence in the suction and mixing chambers of the studied e jector and shock waves interactions both at design and off-desi gn conditions; b. Flow theory analysis Theoretical study and experimental research of binary fluid ejector based on marginal conditions’ theory. 4. Analysis of the fractionating condenser. a. Optimal configuration selection of the fractionating condenser. b. The fractionating condenser design using the PTX properties of the selected binary fluid and ejector system operating paramet ers Comparative analysis of the fractionating condensation methods. Theoretical study of processes in the fractionating condenser, modeling of heat and mass transfer processes. 5. Experimental study of fractionating condenser within the binary fluid e jector system. Analysis of the heat and mass exchange processes; Complex experimental study of binary fluid ejector refrigerat ing system (BERS). Comparative analysis of theoretical and e xperimental data. 6. System analysis at various component fractions in the vapor generator and the evaporator of BERS; Theoretical analysis and experimental study. Comparative an alysis of data. 7. Application of the Maisotsenko Cycle (M-cycle) heat and mass exchang er (HMX) as a condenser for the ejector cooling system. Theoretical analysis and experimental study Benefits: -Simple design, no moving parts -Durability and reliability -Low grade heat (80-100°С) -No sensible to the operating parameters (Binary Fluid ERS) -Comparably high COP (Binary Fluid ERS) -Efficient air conditioning in high humidity climate zones Drawbacks: -High charge volume of working fluid -High dimensional characteristics -Low COP (Single Fluid COP) COP of the ERS is defined by equation: For single fluid: For binary fluid:
Transcript of BINARY FLUID EJECTOR REFRIGERATING … cycle of the ERS. 7-8-1 – heating and boiling in the vapour...
THERMODYNAMIC CYCLES OF ERS AND BERS
Figure 3. Thermodynamic cycle of the ERS. 7-
8-1 – heating and boiling in the vapour
generator; 1-2 – working fluid expansion in the
ejector nozzle; 2-4 and 3-4 – working and
refrigerant vapour mixing; 4 – 4’ – vapour
mixture compression in ejector; 4’-5-6 vapour
condensation; 6-6’ - liquid throttling to
evaporator; 6-7 liquid fluid feeding to the vapour
generator; 6’-3 – refrigerant fluid evaporation in
the evaporator.
q3-6’
q1-7 < 1
qrf
qwf =
Figure 4. Thermodynamic cycle of the BERS.
1-2 – working fluid heating and evaporation
in the vapour generator, 2-3 – working
vapour expansion in the nozzle, 3-4 and 5-4 –
working vapour and refrigerant vapour
mixing in confuser, 4-4’ – mixture
compression in the cylindrical mixing
chamber, 7-8 working fluid condensation in
the fractionating condenser, 6-9 refrigerant
fluid condensation, 8-8’ – refrigerant fluid
throttling, 8-5 – refrigerant fluid evaporation
evaporation, 9-1 – working fluid pumping
into the vapour generator.
q5-8’
q2-1 > 1
qrf
qwf =
* All data received from REFPROP 9.1
EJECTOR REFRIGERATING SYSTEM
1. New concepts and prior art validation of 50-70% efficiency gain while using the binary fluids in the Ejector Refrigerating Systems (ERS) over the single fluid application;
2. Selection of the binary fluid components to achieve the maximum efficiency of the ERS;
3. Analysis of the binary fluids condensation and separation methods, development of the fractionating condenser, designed for the most absolute components separation. Off-design conditions control and adjustment;
4. Develop an in-house code for ERS parameters calculation and validate the binary ejector geometry profile by the CFD analysis of the mixed fluid flows;
5. Develop a prototype system and demonstrate the Binary Fluid ERS technology at a lab scale, experimental data collection and analysis;
6. Characterization of the Binary Fluid Ejector Refrigerating System in the context of its technical energy savings potential, development status, non-energy benefits, and other factors affecting end-user acceptance along with their ability to compete with the conventional vapor-compression or heat operated adsorption/absorption cooling systems
Figure 1. a – the schematic of the single fluid ERS; b – the
schematic of the binary fluid ERS (BERS)
Figure 2. Schematic diagram of ejector.
The main throttling and energy characteristics of ejector is entrainment ratio. The
ejector’s geometry significantly influence ejector’s performance.
Application of CFD modelling allows to optimize the Binary
Ejector geometry to achieve the maximum possible
entrainment ratio at set parameters.
Such approach makes possible to
optimize installation of ejector
refrigerating system on a stage of its
design.
CFD MODELLING OF EJECTOR’S FLOW PART
Working
fluid
qev/qgen U COP
R290/RE170 0.937 0.64 0.60
R600/RE170 0.743 0.66 0.49
R600 0.67 0.51 0.34
RE170 0.767 0.54 0.41
R13T1 0.765 0.44 0.34
R601b 0.615 0.50 0.31
RC318 0.545 0.42 0.23
Results of CFD modelling
PERFORMANCE COMPARISON OF ERS AND BERS
exptheor
comp
lU = -1
l
where U - entrainment ratio, Qeva – cooling capacity, Qgen – consumed heat, qeva - specific cooling capacity, qgen – specific heat
consumed, lexp– work of adiabatic expansion; lcomp– work of adiabatic compression; Utheor– theoretical entrainment ratio, Z –
compression factor, T – temperature, P – pressure, k – adiabatic index, wf and rf – working and refrigerant fluid, gen and eva –
vapour generation and evaporation parameter.
R
wf
gen
wf
gen
k -1
wf wf wf kgen gen
exp wf rfgen eva
Z T Pl = 1-
k -1 P
R
rf
eva
rf
eva
k -1rf rf mix k
eva condcomp rf rf
eva eva
Z T Pl = -1
k -1 P
Figure 5. COP comparisson of Single and Binary Fluid ERS
(1 )rfeva eva
gen gen wf
r xQ qCOP U U
Q q r h
= = =
(0,5 0,9)COP U U<
rf wfr r COP Uusually
BINARY FLUID EJECTOR REFRIGERATING SYSTEM FOR AIR CONDITIONING IN HUMID ZONES
Department of Energy and Environmental Engineering (EEE), Interdisciplinary Graduate School of Engineering Sciences (IGSES),
Kyushu University
RESEARCH BACKGROUND
RESEARCH SUBJECTS AND METHODOLOGY
Research subject Methodology
1. Binary fluid components selection. a. Selection based on “tailored” properties (molecular mass, spee
d of sound, latent heat of evaporation, compressibility factor, ODP, GWP etc.);
b. Definition of the operating parameters.
Computer simulation of mixing and separation processes of binary single-phase fluids, validation of fluids properties at the set parameters.
2. Binary fluid ejector analysis. a. Improvement of the ejector’s calculation algorithm; b. Convergent geometry optimization for shock losses reduction a
t the expense of intake flows angle of attack; c. Ejector CFD modelling. Optimization of the ejector’s flow part d
esign;
Theoretical analysis of the processes in the binary fluid ejector, convergent geometry design for shock losses reduction and flow axis alignment. CFD modeling of binary fluid ejector’s flow part.
3. Theoretical and experimental research of the binary fluid ejector. a. Turbulence in the suction and mixing chambers of the studied e
jector and shock waves interactions both at design and off-design conditions;
b. Flow theory analysis
Theoretical study and experimental research of binary fluid ejector based on marginal conditions’ theory.
4. Analysis of the fractionating condenser. a. Optimal configuration selection of the fractionating condenser. b. The fractionating condenser design using the PTX properties of
the selected binary fluid and ejector system operating parameters
Comparative analysis of the fractionating condensation methods. Theoretical study of processes in the fractionatingcondenser, modeling of heat and mass transfer processes.
5. Experimental study of fractionating condenser within the binary fluid ejector system. Analysis of the heat and mass exchange processes;
Complex experimental study of binary fluid ejector refrigerating system (BERS). Comparative analysis of theoretical and experimental data.
6. System analysis at various component fractions in the vapor generator and the evaporator of BERS;
Theoretical analysis and experimental study. Comparative analysis of data.
7. Application of the Maisotsenko Cycle (M-cycle) heat and mass exchanger (HMX) as a condenser for the ejector cooling system.
Theoretical analysis and experimental study
Benefits:
-Simple design, no moving parts
-Durability and reliability
-Low grade heat (80-100°С)
-No sensible to the operating parameters
(Binary Fluid ERS)
-Comparably high COP (Binary Fluid ERS)
-Efficient air conditioning in high humidity
climate zones
Drawbacks:
-High charge volume of working fluid
-High dimensional characteristics
-Low COP (Single Fluid COP)
COP of the ERS is defined by equation:
For single fluid:
For binary fluid:
