performance improvement of ejector expansion refrigeration
TRANSCRIPT
Thermodynamic and thermoeconomic analysis and
optimization of a novel combined cooling and power (CCP)
cycle by integrating of ejector refrigeration
and Kalina cycles
Arak University of Technology – thermodynamic lab
Dr. Hajizadeh
Reza Barahmand – Sina Amiri Hezaveh
rbarahmand.com
Journal Information
2
Table of Contents
1 Introduction to paper
2 Description of cycle
development
3 Results• About abstract
• System description and assumptions
• *chemical Exergy
• Simulation of thermodynamical cycle
• Simulation Test
• Validation of Simulation and Results
4 Conclusions
3
5 Development
Introduction to paper1
• Prepose of this cycle
• Kalina cycle (KC)
• Ejector refrigeration cycle (ERC)
4
System description and assumptions2
• Inputs
• Assumptions
• Sate points
5
System description and assumptions2
• Inputs
6
System description and assumptions2
• Assumptions
• Energy
• The energy analysis for each control volume is conducted at steady state condition.
• The refrigerant leaving the condenser, evaporator, and separator outlet is saturated.
• Flow across the expansion valves is isenthalpic.
7
System description and assumptions2
• Assumptions
• Exergy
• Since the systems and their components are at rest relative to the environment, the kinetic and potential exergy rates are neglected.
• On account for the rare chemical reactions happening and its negligible value compared with the physical exergy in organic materials, the rate of chemical exergy* is neglected.
• All outer surface of the system is at constant reference temperature. So, the rate of exergy loss is neglected.
8
*chemical Exergy
System description and assumptions2
• Assumptions
• Exergy(*chemical Exergy)
9
*chemical Exergy
Energy, Environment AndSustainable Development(book)
N=14.007 g/mol
H=1.007 g/mol
O=15.008 g/mol
…………………………..
Ecch =95.5 kJ/mol
Ecch =0.0027 kJ/kg
chemical Exergy
System description and assumptions2
• Sate points
❑ Dead state
10
"Dead state"
T_0 = 293 [K]
P_0 = 1 [bar]
h_0 = Enthalpy(Water,T=T_0,P=P_0)
// this is only for water
s_0 = Entropy(Water,T=T_0,P=P_0)
// dead states for the NH3H2O defined in each state
System description and assumptions2
• Sate points
❑ Vapor Generator
11
"Vapor generator"
// Mass balance
m_dot_16 = 10 [kg/s]
m_dot_16 = m_dot_17
m_dot_1 = 0.3655 [kg/s]
// Assuming the inlet mass flow rate of the ejector cycle
m_dot_15 = m_dot_1
// Energy balance
// Check it afer EES
T_16 = 473.2 [K]
T_17 = T_16 - 35.4
P_16 = 1.5 [bar]
P_16 = P_17
// The procces inside the VG is constant pressure
// h_16 = Enthalpy(Water,T=T_16,P=P_16)
// h_17 = Enthalpy(Water,T=T_17,P=P_17)
h_16 = 475.8
h_17 = 439.6
T_1 = 463.2 [K]
P_1 = 1750/100 [bar]
// Assumed from the paper
System description and assumptions2
• Sate points
❑ Vapor Generator
12
// the procces inside the VG is constant pressure
x_1 = 0.15
x_15 = x_1
Call NH3H2O(123, T_1, P_1,x_1 : T_100, P_100, x_100, h_1, s_1, u_1, v_1, Qu_1)
// 123=> T_1,P_1,x_1
(m_dot_16*h_16) + (m_dot_15*h_15) = (m_dot_17*h_17) + (m_dot_1*h_1)
// Entroy balance
s_16 = 6.05
s_17 = 5.97
Call NH3H2O(234, P_15, x_15, h_15 : T_15, P_1500, x_1500, h_1500, s_15, u_15, v_15, Qu_15)
// 234=> P_15,x_15,h_15
(m_dot_16*s_16) + (m_dot_16*s_16) + S_dot_gen_vg = (m_dot_17*s_17) + (m_dot_1*s_1)
// Exergy balance
Edxxxvg = S_dot_gen_vg*T_0
ex_16 = (h_16-h_0)-(T_0*(s_16-s_0))
ex_17 = (h_17-h_0)-(T_0*(s_17-s_0))
Call NH3H2O(123, T_0, P_0,x_1 : T_0100, P_0100, x_0100, h_01, s_01, u_01, v_01, Qu_01)
ex_1 = (h_1-h_01)-(T_0*(s_1-s_01))
ex_15 = (h_15-h_01)-(T_0*(s_15-s_01))
(m_dot_16*ex_16) + (m_dot_15*ex_15) = (m_dot_17*ex_17) + (m_dot_1*ex_1) + E_dot_dest_vg
System description and assumptions2
• Sate points
❑ Separator
13
"Seprator"
// Mass balance
m_dot_2 = 0.3827*m_dot_1
m_dot_1 = m_dot_4 + m_dot_2
// Energy balance
P_4 = P_1
// the process is constant pressure
P_2 = P_1
// the process is constant pressure
T_1 = T_4
// the process is constant Temparature
T_1 = T_2
// the process is constant Temparature
Qu_4 = 0
Qu_2 = 1
Call NH3H2O(128, T_4, P_4, Qu_4 : T_400, P_400, x_4, h_4, s_4, u_4, v_4, Qu_400)
Call NH3H2O(128, T_2, P_2, Qu_2 : T_200, P_200, x_2, h_2, s_2, u_2, v_2, Qu_200)
// (m_dot_1*h_1) = (m_dot_2*h_2) + (m_dot_4*h_4)
// Entropy balance
(m_dot_1*s_1) + S_dot_gen_sep = (m_dot_2*s_2) + (m_dot_4*s_4)
// Exergy balance
Edxxxsep = S_dot_gen_sep*T_0
Call NH3H2O(123, T_0, P_0,x_2 : T_0200, P_0200, x_0200, h_02, s_02, u_02, v_02, Qu_02)
Call NH3H2O(123, T_0, P_0,x_4 : T_0400, P_0400, x_0400, h_04, s_04, u_04, v_04, Qu_04)
ex_2 = (h_2-h_02)-(T_0*(s_2-s_02))
ex_4 = (h_4-h_04)-(T_0*(s_4-s_04))
m_dot_1*ex_1 = (m_dot_4*ex_4) + (m_dot_4*ex_4) + Ex_dot_dest_sep
System description and assumptions2
• Sate points
❑ Expander
14
"Expander"
// Mass balance
m_dot_3 = m_dot_2
// Energy balance
P_3 = P_2/1.5
// Pressure ratio of the Exp is 1.5
(m_dot_2*h_2) = (m_dot_3*h_3) + W_dot_exp
// h_3 is calculated from the entropy balance
// Entropy balance
// We used isentropic efficiency of turbine here
s_2 = s_3s
P_3s = P_3
x_2 = x_3
x_3s = x_3
Call NH3H2O(235, P_3s, x_3s, s_3s : T_3s, P_300s, x_300s, h_3s, s_300s, u_3s, v_3s, Qu_3s)
// 235=> P_3s,x_3s,s_3s
// eta_isen_exp: eta_isen_exp = W_real_exp/W_isen_exp
eta_isen_exp = 0.85
eta_isen_exp = (h_2 - h_3)/(h_2 - h_3s)
// eta 0.85 is one of our problem input, we just calculate h_3
Call NH3H2O(234, P_3, x_3, h_3 : T_3, P_300, x_300, h_300, s_3, u_3, v_3, Qu_3)
(m_dot_2*s_2) + S_dot_gen_exp = (m_dot_3*s_3)
// Exergy balance
Edxxxexp = S_dot_gen_exp*T_0
ex_3 = (h_3-h_0)-(T_0*(s_3-s_0))
(m_dot_2*ex_2) = (m_dot_3*ex_3)+W_dot_exp+Ex_dot_dest_exp
System description and assumptions2
• Sate points
❑ cycle
15
System description and assumptions2
• Sate points
❑ Regenerator
16
"Regenarator"
// Mass balance
m_dot_5 = m_dot_4
m_dot_14 = m_dot_15
// Energy balance
P_5 = P_4
x_5 = x_4
(m_dot_4*h_4) + (m_dot_14*h_14) = (m_dot_5*h_5) + (m_dot_15*h_15)
// Entropy balance
Call NH3H2O(234, P_5, x_5, h_5 : T_5, P_500, x_500, h_500, s_5, u_5, v_5, Qu_5)
(m_dot_4*s_4) + (m_dot_14*s_14) + S_dot_gen_rg = (m_dot_15*s_15) + (m_dot_5*s_5)
// Exergy balance
Exxxrg = S_dot_gen_rg*T_0
ex_5 = (h_5-h_04)-(T_0*(s_5-s_04))
// ex_14 = (h_14-h_01)-(T_0*(s_14-s_01))
(m_dot_4*ex_4) + (m_dot_14*ex_14) = (m_dot_15*ex_15) + (m_dot_5*ex_5) +
E_dot_dest_rg
System description and assumptions2
• Sate points
❑ Expansion valve 1
17
"EX.V 1"
// Change the diagram and codes
// Mass balance
m_dot_7 = m_dot_6
// Energy balance
x_7 = x_6
P_7 = P_6 - 17.487 [kPa]
h_6 = h_7
// Entropy balance
s_6 = s_7
// Exsrgy balance
ex_7 = (h_7-h_04)-(T_0*(s_7-s_04))
(m_dot_6*ex_6) = (m_dot_7*ex_7) + E_dot_dest_exv1
System description and assumptions2
• Sate points
❑ Evaporator
18
"Evaprator"
// Change the diagram and codes
// Mass balance
m_dot_8 = m_dot_7
// Energy balance
x_8 = x_7
T_8 = 283 [K]
// Eva temprature outlet is an Input
P_8 = P_7
Call NH3H2O(123, T_8, P_8, x_8 : T_800, P_800, x_800, h_8, s_8, u_8, v_8, Qu_8)
Q_dot_cooling_eva = m_dot_7*(h_7-h_8)
(m_dot_7*s_7) + S_dot_gen_eva = (m_dot_8*s_8)
// Exergy Balanced
ex_8 = (h_8-h_04)-(T_0*(s_8-s_04))
(m_dot_8*ex_8)+(Q_dot_cooling_eva) = (m_dot_8*ex_8)+Ex_dot_dest_eva
System description and assumptions2
• Sate points
❑ Ejector
19
"Ejector"
// Change the diagram and codes
// Mass balance
m_dot_9 = m_dot_3 + m_dot_8
// Energy balance
// m_dot_9*h_9 = (m_dot_3*h_3) + (m_dot_8*h_8)
h_9 = ((h_3/(1+mu_ejc))+((h_8*mu_ejc)/(1+mu_ejc)))
(m_dot_9*x_9) = (m_dot_3*x_3) + (m_dot_8*x_8)
// Entropy balance
mu_ejc = m_dot_8/m_dot_3
P_9 = 0.3087 [bar]
// Ejectore is designable
Call NH3H2O(234, P_9, x_9, h_9 : T_9, P_900, x_900, h_900, s_9, u_9, v_9, Qu_9)
// Exergy balance
m_dot_9*s_9 = (m_dot_3*s_3)+(m_dot_8*s_8) + S_dot_gen_ejc
// S_dot_gen is alwasye at the inlet side of entropy balance
// Exergy Balanced
Call NH3H2O(123, T_0, P_0,x_9 : T_0900, P_0900, x_0900, h_09, s_09, u_09, v_09, Qu_09)
ex_9 = (h_9-h_09)-(T_0*(s_9-s_09))
(m_dot_9*ex_9) + Ex_dot_dest_ejc = (m_dot_8*ex_8) + (m_dot_3*ex_3)
System description and assumptions2
• Sate points
❑ Expansion valve 2
20
"EX.V 2"
// Change the diagram and codes
// Mass balance
m_dot_11 = m_dot_10
// Energy balance
x_11 = x_10
P_11 = P_9
h_11 = h_10
// Entropy balance
s_11 = s_10
// Exsrgy balance
ex_11 = (h_11-h_04)-(T_0*(s_11-s_04))
(m_dot_11*ex_11) = (m_dot_10*ex_10) + E_dot_dest_exv2
System description and assumptions2
• Sate points
❑ Expansion valve 1,2
21
"Valve"
m_dot_6 = 0.11*m_dot_5
m_dot_5 = m_dot_10 + m_dot_6
// Energy balance
P_6 = P_5
P_10 = P_5
x_6 = x_5
x_10 = x_5
h_6 = h_5
h_10 = h_5
// Entropy balance
s_10 = s_5
s_6 = s_5
// Exergy balance
ex_10 = ex_5
ex_6 = ex_5
System description and assumptions2
• Sate points
❑ Mixer
22
"Mixer"
// Mass balance
x_12 = x_1
m_dot_12 = m_dot_11 + m_dot_9
// Energy balance
m_dot_12*h_12 = (m_dot_11*h_11)+(m_dot_9*h_9)
// Entropy Balanced
P_12 = P_9
Call NH3H2O(234, P_12, x_12, h_12 : T_12, P_1200, x_1200, h_1200, s_12, u_12,
v_12, Qu_12)
m_dot_12*s_12 = (m_dot_11*s_11) + (m_dot_9*s_9) + S_dot_gen_mix
// Exergy Balanced
ex_12 = (h_12-h_01)-(T_0*(s_12-s_01))
m_dot_12*ex_12 = (m_dot_11*ex_11)+(m_dot_9*ex_9)+Ex_dot_dest_mix
System description and assumptions2
• Sate points
❑ Condenser
23
"Condenser - Water"
// Mass balance
m_dot_13 = m_dot_12
m_dot_18 = 19.73 [kg/s]
m_dot_19 = m_dot_18
// Energy balance
x_13 = x_15
Qu_13 = 0
Q_dot_cond = m_dot_12*(h_12 - h_13)
// Saturated Liquid
P_13 = P_12
P_18 = 1 [bar]
P_19 = P_18
T_18 = 293.2 [K]
T_19 = T_18 + 5
Call NH3H2O(238, P_13, x_13, Qu_13 : T_13, P_1300, x_1300, h_13, s_13, u_13, v_13, Qu_1300)
ex_13 = (h_13-h_01)-(T_0*(s_13-s_01))
// Condenser pinch point is given
System description and assumptions2
• Sate points
❑ pump
24
"Pump "
// Mass balance
// m_dot_14 = m_dot_13
// Energy balance
P_14 = 17.5 [bar]
// pressures after pumps and turbines are known and is constant
(m_dot_13*h_13)+(W_dot_pump) = m_dot_14*h_14
// h_14 is calculated from the entropy balance
// Entropy balance
// We used isentropic efficiency of pump here
s_13 = s_14s
P_14s = P_14
x_14 = x_13
x_14s = x_14
Call NH3H2O(235, P_14s, x_14s, s_14s : T_14s, P_14s00, x_14s00, h_14s, s_14s00, u_14s, v_14s, Qu_14s)
// eta_isen_pump: eta_isen_pump = W_isen_pump/W_real_pump
// eta_isen_pump = 0.85
eta_isen_pump = 0.85
eta_isen_pump = (h_14s - h_13)/(h_14 - h_13)
// eta 0.85 is one of our problem input, we just calculate h_14
// s_14
Call NH3H2O(234, P_14, x_14, h_14 : T_14, P_1400, x_1400, h_1400, s_14, u_14, v_14, Qu_14)
// Exergy balance
ex_14 = (h_14-h_01)-(T_0*(s_14-s_01))
(m_dot_13*ex_13)+(W_dot_Pump) = (m_dot_14*ex_14)+Ex_dot_dest_Pump
System description and assumptions2
• Sate points
❑ cycle
25
Results 2
• plots
❑ The effect of vapor generator pressure on the cooling output, net power output, thermal efficiency, exergy efficiency, and SUCP of the system.
26
Results 2
• plots
❑The effect of vapor generator temperature on the cooling output, net power output, thermal efficiency, exergy efficiency, and SUCP of the system.
27
Results 2
• plots
• The effect of evaporator temperature on the cooling output, net power output, thermal efficiency, exergy efficiency, and SUCP of the system
28
Results 2
• plots
❑The effect of ammonia concentration on the cooling output, net power output, thermal efficiency, exergy efficiency, and SUCP of the system.
29
Conclusion4
• Conclusion
30
Development5
31
Development5
32
Generator → Vaper Generator
Development5
33
W_dot_net = 750 kW
Q_cooling is same with Ejector cycle
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