# Energy and Exergy Analyses of Forced Draft Fan for Marine Steam Propulsion System during Load Change

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Energy and Exergy Analyses

## 3. Specifications and Operating Characteristics

## 4. Mathematical Description and Equations

#### 4.1. General Equations for Energy and Exergy Analyses

#### 4.2. Energy And Exergy Analyses of The Forced Draft Fan

#### 4.3. Shaft Power Calculation

_{em}= 96%.

## 5. Forced Draft Fan-Measurement Equipment and Data

## 6. Results and Discussion

^{−1}), the fan driving power is 80.99 kW and increases almost continuously during an increase in the steam system load. At the highest system load (83.00 min

^{−1}), the fan driving power is equal to 157.63 kW. The presented change in the fan driving power is expected because an increase in the steam system load simultaneously increases the fuel amount into the steam generator. An increase in the fuel consumption leads to an increase in the air mass flow rate supplied to the steam generator by the forced draft fan in order to maintain complete combustion. The higher air mass flow rates through the forced draft fan necessitate higher power consumptions in the fan drive. This fact is justified with the simultaneous change of the forced draft fan power consumption and the change in the air mass flow rate, as shown in Figure 4 and Table 4.

^{−1}) and are equal to 9192 kW for the energy power input and 9117 kW for the energy power output.

^{−1}), the electrical drive power represents a share lower than 2.5% in the energy power input for all of the steam system loads.

^{−1}), the share of electrical drive power share reduced to 2.22% due to a significant increase in the air mass flow rate through the fan (from 4.80 kg/s at 0.00 min

^{−1}up to 11.24 kg/s at 25.58 min

^{−1}). At the highest steam system load (propeller speed of 83.00 min

^{−1}), the air mass flow rate through the forced draft fan is the highest (Table 4) and the share of electrical drive power in the energy power input is the lowest with 1.71%.

^{−1}(Figure 7), where the air temperature difference between the fan outlet and inlet is 6 °C (Table 4). When observing the propulsion propeller speeds between 63.55 min

^{−1}and 70.37 min

^{−1}, it can be seen that the highest energy power losses of the forced draft fan are between 99.9 kW and 105.8 kW, while the air temperature difference is 2 °C (Table 4). For the highest steam system loads, the fan energy power loss varies significantly. At 81.49 min

^{−1}and 83.00 min

^{−1}the fan energy power losses are 74.9 kW and 74.8 kW, with an air temperature difference of 4 °C. At 82.88 min

^{−1}the fan energy power loss is 95.5 kW and the air temperature difference between fan outlet and inlet is 3 °C.

^{−1}) to 63.4% (at 53.50 min

^{−1}). At the highest steam system load (83.00 min

^{−1}), the forced draft fan energy efficiency is 52.5%, which is important since, at this system load, LNG carriers operate for the major part of the time. It can be concluded that, on average, the energy efficiency of the analyzed forced draft fan is below 40% for in the low to middle range of system loads. The fan energy efficiency increases to 50%, on average, only at the highest steam system loads (from 81.49 min

^{−1}to 83.00 min

^{−1}).

^{−1}, while the highest fan exergy power input of 164.2 kW occurs at the highest system load (83.00 min

^{−1}). The lowest values of exergy power input and output are obtained for propeller speed of 0.00 min

^{−1}, while the highest values of exergy power input and output are obtained for propeller speed of 83.00 min

^{−1}.The lowest exergy power output is 8.9 kW, while the highest exergy power output is 91.6 kW. The exergy power output is not influenced by the electrical drive power since it contains only the exergy power of the air flow stream (Equation (17)).

^{−1}and 56.65 min

^{−1}. The main reason for the sudden increase from 41.78 min

^{−1}to 53.50 min

^{−1}is a significant increase in the electrical drive power, from 111.93 kW to 121.25 kW. The exergy power input of the air flow stream increases by only 2.28 kW between these two propeller speeds, mostly because the air mass flow rate increases from 11.09 kg/s to 12.75 kg/s (Table 4). The increase in the air mass flow rate is the main reason for the fan exergy power output increase between propeller speeds of 41.78 min

^{−1}and 53.50 min

^{−1}. However, it should be noted that the air temperature increase at the fan outlet, which is from 45 °C to 50 °C, also influences the observed increase in the fan exergy power output.

^{−1}to 56.65 min

^{−1}. This is mainly caused by the decrease of electrical drive power from 121.25 kW to 117.91 kW. Between these two propeller speeds, the exergy power input of the air flow stream shows a decrease of 2.96 kW, caused mostly by the decrease in air mass flow rate from 12.75 kg/s to 12.28 kg/s (Table 4). Between propeller speeds of 53.50 min

^{−1}. and 56.65 min

^{−1}, the decrease in fan exergy power output is caused by the decrease of air temperature at the fan outlet, from 50 °C to 44 °C, while the decrease of air mass flow rate has an important, but not primary influence.

^{−1}), the shares of electrical drive power and air flow exergy power in the fan exergy power input exhibit abrupt changes, which are caused by the changes in the air mass flow rates. In the range of propulsion propeller speeds from 63.55 min

^{−1}to 83.00 min

^{−1}, the share of air flow exergy power shows a continuous increase, while the share of electrical drive power share shows a continuous decrease. Again, these trends are for the major part influenced by the change in the air mass flow rate.

^{−1}, while the lowest exergy destruction of 72.6 kW occurs for the highest propulsion propeller speed of 83.00 min

^{−1}. In the entire range of steam system loads, the average exergy destruction is 95.95 kW.

^{−1}to 83.00 min

^{−1}. In this load range, the air mass flow rate and the fan driving power increase almost continuously. The air temperature and pressure at the fan inlet are constant in that load range, while the air temperature at the fan outlet is almost constant, as reported in Table 4. The term ${\dot{m}}_{1}\xb7({\epsilon}_{1}-{\epsilon}_{2})$ reduces the exergy destruction when the system load increases since the air pressure at the fan outlet continuously increases. An exception occurs between propulsion propeller speeds of 80.44 min

^{−1}and 81.49 min

^{−1}where the fan exergy destruction slightly increases. The continuous increase of air pressure at the fan outlet, with almost constant air temperature, causes a continuous increase in the outlet air specific exergy. Along with the increase in air mass flow rate, the increase in air specific exergy at the fan outlet causes the term ${\dot{m}}_{1}\xb7({\epsilon}_{1}-{\epsilon}_{2})$ to increase faster than the fan driving power, which reduces the fan exergy destruction (Equation (18)) in the range of propeller speeds from 71.03 min

^{−1}to 83.00 min

^{−1}.

^{−1}, at the steam system startup. The highest fan exergy efficiency is 53.93% and occurs for the highest air mass flow rate of 20.60 kg/s (driving power 157.63 kW) when the propulsion propeller speed is 83.00 min

^{−1}.

^{−1}and 82.88 min

^{−1}. Between propulsion propeller speeds of 80.44 min

^{−1}and 81.49 min

^{−1,}a slight decrease in the fan exergy efficiency (from 49.43% down to 49.06%) can be seen in Figure 10. This decrease occurs because the air mass flow rate decreases from 20.23 kg/s to 20.11 kg/s, while the fan driving power decreases from 156.18 kW to 155.71 kW.

^{−1}to 82.88 min

^{−1}, the fan exergy efficiency increases from 49.06% to 52.54%. This is caused by the increase in the air mass flow rate from 20.11 kg/s to 20.50 kg/s, while the fan driving power increases from 155.71 kW to 157.25 kW.

^{−1}to 74.59 min

^{−1}), the fan exergy destruction increases with an increase in the ambient temperature. In this range of steam system loads, the lowest fan exergy destruction is 75.85 kW and occurs for ambient temperature of 10 °C (0.00 min

^{−1}). On the other hand, the highest fan exergy destruction is 108.53 kW and occurs for ambient temperature of 40 °C (62.52 min

^{−1}). In this range of steam system loads, the average exergy destructions are: 100.74 kW for ambient temperature of 10 °C and 102.20 kW for ambient temperature of 40 °C. An increase in ambient temperature of 10 °C causes an increase of exergy destruction by 0.49 kW on average, in the range of low to middle steam system loads.

^{−1}to 83.00 min

^{−1}), the change in exergy destruction is very interesting. In this load range, fan exergy destruction decreases with an increase in ambient temperature, with the exception at propeller speed of 81.49 min

^{−1}. This is an unusual change for most of steam plant components and must be explained in detail.

^{−1}to 74.59 min

^{−1}), an increase in ambient temperature of 10 °C causes a decrease in air specific exergy at the fan outlet (${\epsilon}_{2}$) larger than the decrease in air specific exergy at the fan inlet (${\epsilon}_{1}$). Therefore, from Equation (18), the term ${\dot{m}}_{1}\xb7({\epsilon}_{1}-{\epsilon}_{2})$ increases with an increase in ambient temperature, which leads to a larger exergy destruction, in the range of propeller speeds between 0.00 min

^{−1}and 74.59 min

^{−1}.

^{−1}to 83.00 min

^{−1}, a different trend is detected. An increase in ambient temperature of 10 °C causes a decrease in air specific exergy at the fan outlet (${\epsilon}_{2}$) smaller than the decrease in air specific exergy at the fan inlet (${\epsilon}_{1}$). Therefore, from Equation (18), the term ${\dot{m}}_{1}\xb7({\epsilon}_{1}-{\epsilon}_{2})$ decreases with an increase in ambient temperature, which leads to a smaller exergy destruction, in the range of propeller speeds between 76.56 min

^{−1}and 83.00 min

^{−1}. At high steam system loads, the only exception occurs at the propulsion propeller speed of 81.49 min

^{−1}where an increase in ambient temperature leads to an increase in exergy destruction, same as in the range of low to middle steam system loads.

^{−1}to 83.00 min

^{−1}), the average exergy destruction is 82.10 kW at ambient temperature of 10 °C, while it is 81.37 kW at ambient temperature of 40 °C. Thus, an increase in ambient temperature of 10 °C causes an average decrease of fan exergy destruction by 0.25 kW.

^{−1}to 74.59 min

^{−1}, an increase in ambient temperature causes a decrease in the exergy efficiency of the forced draft fan. In this load range, the lowest fan exergy efficiency is 3.86% and occurs for propulsion propeller speed of 0.00 min

^{−1}and ambient temperature of 40 °C. On the other hand, the highest fan exergy efficiency is 32.15% and occurs for propulsion propeller speed of 74.59 min

^{−1}and ambient temperature of 10 °C. In the range of low to middle steam system loads, the average exergy efficiency is 19.66% for ambient temperature of 10 °C and 18.43% for ambient temperature of 40 °C. An increase in the ambient temperature of 10 °C causes a decrease in the fan exergy efficiency by 0.41%, on average.

^{−1}and 83.00 min

^{−1}, an increase in ambient temperature causes an increase in the exergy efficiency for almost all of the observed steam system loads. The lowest fan exergy efficiency is 38.12% and is obtained for the propulsion propeller speed of 76.56 min

^{−1}and ambient temperature of 10 °C. On the other hand, the highest fan exergy efficiency is 54.00% and is obtained for the propulsion propeller speed of 83.00 min

^{−1}and ambient temperature of 40 °C. The average exergy efficiency is 46.86% when ambient temperature is 10 °C and 47.33% when ambient temperature is 40 °C. An increase in ambient temperature of 10 °C causes an increase in fan exergy efficiency by 0.16%, on average, in the range of high steam system loads. The only exception is seen at the propulsion propeller speed of 81.49 min

^{−1}.

## 7. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## Nomenclature

Abbreviations: | |

AC | Alternating Current |

CFD | Computational Fluid Dynamics |

DC | Direct Current |

LNG | Liquefied Natural Gas |

RMS | Root-Mean-Square |

SCR | Selective Catalytic Reduction |

Latin Symbols: | |

c | velocity, m/s |

$\dot{E}$ | stream flow power, kW |

g | acceleration of gravity, m/s2 |

$h$ | specific enthalpy, kJ/kg |

I | current, A |

$\dot{m}$ | mass flow rate, kg/s or kg/h |

p | pressure, MPa or bar |

P | power, kW |

PF | power factor, - |

$\dot{Q}$ | heat transfer, kW |

$s$ | specific entropy, kJ/kg·K |

T | temperature, °C or K |

U | voltage, V |

${\dot{X}}_{\mathrm{heat}}$ | heat exergy transfer, kW |

z | elevation, m |

Greek symbols: | |

$\epsilon $ | specific exergy, kJ/kg |

$\eta $ | efficiency, - |

Subscripts: | |

0 | ambient conditions |

D | destruction |

em | electrical motor |

en | energy |

ex | exergy |

i | index of fluid flow stream |

IN | inlet (input) |

OUT | outlet (output) |

PL | power loss |

## Appendix A

**Propulsion propeller speed:**

**Table A1.**Kyma Shaft Power Meter (KPM-PFS)—reproduced from [87].

Accuracy | Absolute | Relative |
---|---|---|

Torque | < ± 0.5% | < ± 0.5% |

Thrust | < ± 5.0% | < ± 5.0% |

Revolution | < ± 0.1% | < ± 0.1% |

Driving power * | < ± 0.5% | < ± 0.5% |

*****Driving power is calculated from torque and revolutions.

**Air mass flow rate-forced draft fan inlet and outlet:**

**Table A2.**Yamatake JTD930A-Differential Pressure Transmitter—reproduced from [88].

Measuring Range: | 35 kPa–700 kPa |

Setting span: | −100 kPa–700 kPa |

Operating pressure range: | 2.0 kPa–14 MPa |

**Air temperature- forced draft fan inlet and outlet:**

**Table A3.**Greisinger GTF 401-Pt100-Immersion probe—reproduced from [89].

Measuring range: | from −50 °C up to +400 °C |

Response time: | approx. 10 s |

Standard: | DIN class B |

Error ranges: | ± (0.30 + 0.00500) |Temp in °C| |

**Air pressure-forced draft fan inlet and outlet:**

**Table A4.**Yamatake JTG940A-Pressure Transmitter—reproduced from [90].

Measuring range: | 35 kPa–3500 kPa |

Setting span: | −100 kPa–3500 kPa |

Operating pressure range: | 2.0 kPa–3500 kPa |

**Forced draft fan electrical drive current:**

**Table A5.**Fluke a3002 FC Wireless AC/DC Current Module—reproduced from [91].

Maximum AC: | 600 A |

Maximum DC: | 1000 A |

Current accuracy: | DC: 0.5% + 3 Digits AC: 1% + 3 Digits |

Operating temperature: | from −10 °C up to +50 °C |

## References

- Bloch, H.P. Petrochemical Machinery Insights; Elsevier Inc.: Amsterdam, The Netherlands, 2017. [Google Scholar]
- Dixon, S.L.; Hall, C.A. Fluid Mechanics and Thermodynamics of Turbomachinery, 6th ed.; Elsevier Inc.: Amsterdam, The Netherlands, 2010. [Google Scholar]
- Ye, X.; Ding, X.; Zhang, J.; Li, C. Numerical simulation of pressure pulsation and transient flow field in an axial flow fan. Energy
**2017**, 129, 185–200. [Google Scholar] [CrossRef] - He, W.; Dai, Y.; Zhu, S.; Han, D.; Yue, C.; Pu, W. Influence from the blade installation angle of the windward axial fans on the performance of an air-cooled power plant. Energy
**2013**, 60, 416–425. [Google Scholar] [CrossRef] - He, W.; Dai, Y.; Han, D.; Yue, C.; Pu, W. Influence from the rotating speed of the windward axial fans on the performance of an air-cooled power plant. Appl. Ther. Eng.
**2014**, 65, 14–23. [Google Scholar] [CrossRef] - Bizjan, B.; Milavec, M.; Širok, B.; Trenc, F.; Hočevar, M. Energy dissipation in the blade tip region of an axial fan. J. Sound Vib.
**2016**, 382, 63–72. [Google Scholar] [CrossRef] - Lu, J.; Lu, F.; Huang, J. Performance Estimation and Fault Diagnosis Based on Levenberg–Marquardt Algorithm for a Turbofan Engine. Energies
**2018**, 11, 181. [Google Scholar] [CrossRef] - Sharanabasaweshwara, A.A.; Syed Firasat, A. Parametric Study of a Turbofan Engine with an Auxiliary High-Pressure Bypass. Int. J. Turbomach. Propuls. Power
**2019**, 4, 2. [Google Scholar] [CrossRef] - Huang, G.; Xiang, X.; Xia, C.; Lu, W.; Li, L. Feasible Concept of an Air-Driven Fan with a Tip Turbine for a High-Bypass Propulsion System. Energies
**2018**, 11, 3350. [Google Scholar] [CrossRef] - Lu, W.; Huang, G.; Xiang, X.; Wang, J.; Yang, Y. Thermodynamic and Aerodynamic Analysis of an Air-Driven Fan System in Low-Cost High-Bypass-Ratio Turbofan Engine. Energies
**2019**, 12, 1917. [Google Scholar] [CrossRef] - Stafford, J.; Walsh, E.; Egan, V. A study on the flow field and local heat transfer performance due to geometric scaling of centrifugal fans. Int. J. Heat Fluid Flow
**2011**, 32, 1160–1172. [Google Scholar] [CrossRef] - Lin, S.C.; Tsai, M.L. An integrated performance analysis for a backward-inclined centrifugal fan. Comput. Fluids
**2012**, 56, 24–38. [Google Scholar] [CrossRef] - Gholamian, M.; Rao, G.K.M.; Panitapu, B. Effect of axial gap between inlet nozzle and impeller on efficiency and flow pattern in centrifugal fans, numerical and experimental analysis. Case Stud. Ther. Eng.
**2013**, 1, 26–37. [Google Scholar] [CrossRef] [Green Version] - Chunxi, L.; Ling, W.S.; Yakui, J. The performance of a centrifugal fan with enlarged impeller. Energy Convers. Manag.
**2011**, 52, 2902–2910. [Google Scholar] [CrossRef] - Fernández Oro, J.M.; Pereiras García, B.; González, J.; Argüelles Díaz, K.M.; Velarde-Suárez, S. Numerical Methodology for the Assessment of Relative and Absolute Deterministic Flow Structures in the Analysis of Impeller-Tongue Interactions for Centrifugal Fans. Comput. Fluids
**2013**, 86, 310–325. [Google Scholar] [CrossRef] - Lin, S.C.; Huang, C.L. An integrated experimental and numerical study of forward–curved centrifugal fan. Exp. Ther. Fluid Sci.
**2002**, 26, 421–434. [Google Scholar] [CrossRef] - Tsai, B.J.; Wu, C.L. Investigation of a miniature centrifugal fan. Appl. Ther. Eng.
**2007**, 27, 229–239. [Google Scholar] [CrossRef] - Chen, G.; Xu, W.; Zhao, J.; Zhang, H. Energy-Saving Performance of Flap-Adjustment-Based Centrifugal Fan. Energies
**2018**, 11, 162. [Google Scholar] [CrossRef] - Paramasivam, K.; Rajoo, S.; Romagnoli, A.; Yahya, W.J. Tonal noise prediction in a small high speed centrifugal fan and experimental validation. Appl. Acoust.
**2017**, 125, 59–70. [Google Scholar] [CrossRef] - Sanjose, M.; Moreau, S. Direct noise prediction and control of an installed large low-speed radial fan. Eur. J. Mech. B
**2017**, 61, 235–243. [Google Scholar] [CrossRef] [Green Version] - Trabelsi, H.; Abid, M.; Taktak, M.; Fakhfakh, T.; Haddar, M. Effect of the aerodynamic force modeling on the tonal noise prediction model for axial fan: Sensitivity and uncertainty analysis. Appl. Acoust.
**2017**, 117, 61–65. [Google Scholar] [CrossRef] - Wolfram, D.; Carolus, T.H. Experimental and numerical investigation of the unsteady flow field and tone generation in an isolated centrifugal fan impeller. J. Sound Vib.
**2010**, 329, 4380–4397. [Google Scholar] [CrossRef] - Zhang, J.; Chu, W.; Zhang, H.; Wu, Y.; Dong, X. Numerical and experimental investigations of the unsteady aerodynamics and aero-acoustics characteristics of a backward curved blade centrifugal fan. Appl. Acoust.
**2016**, 110, 256–267. [Google Scholar] [CrossRef] - Qi, D.; Mao, Y.; Jun, L.; Yuan, M. Experimental study on the noise reduction of an industrial forward-curved blades centrifugal fan. Appl. Acoust.
**2009**, 70, 1041–1050. [Google Scholar] [CrossRef] - Zhang, W.; Wang, X.; Jing, X.; Liang, A.; Sun, X. Three-dimensional analysis of vane sweep effects on fan interaction noise. J. Sound Vib.
**2017**, 391, 73–94. [Google Scholar] [CrossRef] - Zhang, J.; Chu, W.; Zhang, J.; Lv, Y. Vibroacoustic Optimization Study for the Volute Casing of a Centrifugal Fan. Appl. Sci.
**2019**, 9, 859. [Google Scholar] [CrossRef] - Nurbanasari, M.; Kristyadi, T.; Purwanto, T.S.; Maulana, A.; Fadilah, R.R. Damage analysis of the forced draft fan blade in coal fired power plant. Case Stud. Eng. Fail. Anal.
**2017**, 8, 49–56. [Google Scholar] [CrossRef] - Trebuna, F.; Šimcák, F.; Bocko, J.; Trebuna, P. Identification of causes of radial fan failure. Eng. Fail. Anal.
**2009**, 16, 2054–2065. [Google Scholar] [CrossRef] - Vaccarini, M.; Carbonari, A.; Casals, M. Development and calibration of a model for the dynamic simulation of fans with induction motors. Appl. Ther. Eng.
**2017**, 111, 647–659. [Google Scholar] [CrossRef] [Green Version] - Ding, S.; Liu, J.; Zhang, L. Fan characteristics of the self-support components of rotor ends and its performance matching. Int. J. Heat Mass Transf.
**2017**, 108, 1917–1923. [Google Scholar] [CrossRef] - Viorel-Mihai, N.; Ioan, C. The vibrations’ study to the burn gas exhaust fan from a thermoelectric power plant. Appl. Math. Model.
**2017**, 43, 454–463. [Google Scholar] [CrossRef] - Wang, Y.; Ma, Z.; Shen, Y.; Tang, Y.; Ni, M.; Chi, Y.; Yan, J.; Cen, K. A power-saving control strategy for reducing the total pressure applied by the primary air fan of a coal-fired power plant. Appl. Energy
**2016**, 175, 380–388. [Google Scholar] [CrossRef] - Wang, Y.; Tan, H.; Dong, K.; Liu, H.; Xiao, J.; Zhang, J. Study of ash fouling on the blade of induced fan in a 330 MW coal-fired power plant with ultra-low pollutant emission. Appl. Ther. Eng.
**2017**, 118, 283–291. [Google Scholar] [CrossRef] - Kowalczyk, T.; Ziółkowski, P.; Badur, J. Exergy Losses in the Szewalski Binary Vapor Cycle. Entropy
**2015**, 17, 7242. [Google Scholar] [CrossRef] - Uysal, C.; Kurt, H.; Kwak, H.Y. Exergetic and thermoeconomic analyses of a coal-fired power plant. Int. J. Ther. Sci.
**2017**, 117, 106–120. [Google Scholar] [CrossRef] - Bühler, F.; Van Nguyen, T.; Kjær Jensen, J.; Müller Holm, F.; Elmegaard, B. Energy, exergy and advanced exergy analysis of a milk processing factory. Energy
**2018**, 162, 576–592. [Google Scholar] [CrossRef] [Green Version] - Taner, T. Optimisation processes of energy efficiency for a drying plant: A case of study for Turkey. Appl. Ther. Eng.
**2015**, 80, 247–260. [Google Scholar] [CrossRef] - Naserbegi, A.; Aghaie, M.; Minuchehr, A.; Alahyarizadeh, G.H. A novel exergy optimization of Bushehr nuclear power plant by gravitational search algorithm (GSA). Energy
**2018**, 148, 373–385. [Google Scholar] [CrossRef] - Serrano-Sanchez, C.; Olmeda-Delgado, M.; Petrakopoulou, F. Exergy and Economic Evaluation of a Hybrid Power Plant Coupling Coal with Solar Energy. Appl. Sci.
**2019**, 9, 850. [Google Scholar] [CrossRef] - Siddiqui, M.E.; Taimoor, A.A.; Almitani, K.H. Energy and Exergy Analysis of the S-CO
_{2}Brayton Cycle Coupled with Bottoming Cycles. Processes**2018**, 6, 153. [Google Scholar] [CrossRef] - Ahmadi, G.; Toghraie, D.; Akbari, O.A. Energy, exergy and environmental (3E) analysis of the existing CHP system in a petrochemical plant. Renew. Sustain. Energy Rev.
**2019**, 99, 234–242. [Google Scholar] [CrossRef] - Yilmaz, F. Thermodynamic performance evaluation of a novel solar energy based multigeneration system. Appl. Ther. Eng.
**2018**, 143, 429–437. [Google Scholar] [CrossRef] - Mrzljak, V.; Poljak, I.; Žarković, B. Exergy Analysis of Steam Pressure Reduction Valve in Marine Propulsion Plant on Conventional LNG Carrier. Int. J. Marit. Sci. Technol.
**2018**, 65, 24–31. [Google Scholar] [CrossRef] - Blažević, S.; Mrzljak, V.; Anđelić, N.; Car, Z. Comparison of energy flow stream and isentropic method for steam turbine energy analysis. Acta Polytech.
**2019**, 59, 109–125. [Google Scholar] [CrossRef] - Baldi, F.; Johnson, H.; Gabrielii, C.; Andersson, K. Energy and Exergy Analysis of Ship Energy Systems—The Case study of a Chemical Tanker. Int. J. Thermodyn.
**2015**, 18, 82–93. [Google Scholar] [CrossRef] - Baldi, F.; Ahlgren, F.; Van Nguyen, T.; Thern, M.; Andersson, K. Energy and Exergy Analysis of a Cruise Ship. Energies
**2018**, 11, 2508. [Google Scholar] [CrossRef] - Koroglu, T.; Sogut, O.S. Conventional and Advanced Exergy Analyses of a Marine Steam Power Plant. Energy
**2018**, 163, 392–403. [Google Scholar] [CrossRef] - Mrzljak, V.; Senčić, T.; Žarković, B. Turbogenerator Steam Turbine Variation in Developed Power: Analysis of Exergy Efficiency and Exergy Destruction Change. Model. Simul. Eng.
**2018**, 2018, 2945325. [Google Scholar] [CrossRef] - Mrzljak, V.; Poljak, I.; Prpić-Oršić, J. Exergy analysis of the main propulsion steam turbine from marine propulsion plant. Shipbuild. Theory Pract. Nav. Archit. Mar. Eng. Ocean Eng.
**2019**, 70, 59–77. [Google Scholar] [CrossRef] - Koroglu, T.; Sogut, O.S. Advanced exergy analysis of an organic Rankine cycle waste heat recovery system of a marine power plant. J. Ther. Eng.
**2017**, 3, 1136–1148. [Google Scholar] [CrossRef] - Ikegami, Y.; Yasunaga, T.; Morisaki, T. Ocean Thermal Energy Conversion Using Double-Stage Rankine Cycle. J. Mar. Sci. Eng.
**2018**, 6, 21. [Google Scholar] [CrossRef] - Author Name Ono, Y.; Uchida, I.; Nakano, K. Main Boiler (MB-4E-KS) Forced Draft Fan, H. No. 1728/29/30 Shipyard & Machinery Works, Internal LNG Carrier Documentation; Mitsubishi Heavy Industries, Ltd.: Nagasaki, Japan, 2004. [Google Scholar]
- Valencia, G.; Fontalvo, A.; Cárdenas, Y.; Duarte, J.; Isaza, C. Energy and Exergy Analysis of Different Exhaust Waste Heat Recovery Systems for Natural Gas Engine Based on ORC. Energies
**2019**, 12, 2378. [Google Scholar] [CrossRef] - Adibhatla, S.; Kaushik, S.C. Energy, exergy, economic and environmental (4E) analyses of a conceptual solar aided coal fired 500 MWe thermal power plant with thermal energy storage option. Sustain. Energy Technol. Assess.
**2017**, 21, 89–99. [Google Scholar] [CrossRef] - Mrzljak, V.; Poljak, I.; Medica-Viola, V. Thermodynamical analysis of high-pressure feed water heater in steam propulsion system during exploitation. Shipbuild. Theory Pract. Nav. Archit. Mar. Eng. Ocean Eng.
**2017**, 68, 45–61. [Google Scholar] [CrossRef] - Poljak, I.; Orović, J.; Mrzljak, V. Energy and exergy analysis of the condensate pump during internal leakage from the marine steam propulsion system. Sci. J. Mar. Res.
**2018**, 32, 268–280. [Google Scholar] [CrossRef] - Yildirim, E.; Altuntas, O.; Mahir, N.; Karakoc, T.H. Energy, exergy analysis, and sustainability assessment of different engine powers for helicopter engines. Int. J. Green Energy
**2017**, 14, 1093–1099. [Google Scholar] [CrossRef] - Ahmadi, G.R.; Toghraie, D. Energy and exergy analysis of Montazeri Steam Power Plant in Iran. Renew. Sustain. Energy Rev.
**2016**, 56, 454–463. [Google Scholar] [CrossRef] - Orović, J.; Mrzljak, V.; Poljak, I. Efficiency and Losses Analysis of Steam Air Heater from Marine Steam Propulsion Plant. Energies
**2018**, 11, 3019. [Google Scholar] [CrossRef] - Mrzljak, V.; Prpić-Oršić, J.; Senčić, T. Change in steam generators main and auxiliary energy flow streams during the load increase of LNG carrier steam propulsion system. Sci. J. Mar. Res.
**2018**, 32, 121–131. [Google Scholar] [CrossRef] - Ameri, M.; Mokhtari, H.; Mostafavi Sani, M. 4E analyses and multi-objective optimization of different fuels application for a large combined cycle power plant. Energy
**2018**, 156, 371–386. [Google Scholar] [CrossRef] - Mrzljak, V.; Poljak, I.; Medica-Viola, V. Dual fuel consumption and efficiency of marine steam generators for the propulsion of LNG carrier. Appl. Ther. Eng.
**2017**, 119, 331–346. [Google Scholar] [CrossRef] - Kanoğlu, M.; Çengel, Y.A.; Dincer, I. Efficiency Evaluation of Energy Systems; Springer Briefs in Energy; Springer: Berlin/Heidelberg, Germany, 2012. [Google Scholar] [CrossRef]
- Sadi, M.; Arabkoohsar, A. Exergoeconomic analysis of a combined solar-waste driven power plant. Renew. Energy
**2019**, 141, 883–893. [Google Scholar] [CrossRef] - Szargut, J. Exergy Method—Technical and Ecological Applications; WIT Press: Southampton, UK, 2005. [Google Scholar]
- Elsafi, A.M. Exergy and exergoeconomic analysis of sustainable direct steam generation solar power plants. Energy Convers. Manag.
**2015**, 103, 338–347. [Google Scholar] [CrossRef] - Ahmadi, G.; Toghraie, D.; Akbari, O.A. Technical and environmental analysis of repowering the existing CHP system in a petrochemical plant: A case study. Energy
**2018**, 159, 937–949. [Google Scholar] [CrossRef] - Lorencin, I.; Anđelić, N.; Mrzljak, V.; Car, Z. Exergy analysis of marine steam turbine labyrinth (gland) seals. Sci. J. Mar. Res.
**2019**, 33, 76–83. [Google Scholar] [CrossRef] - Nazari, N.; Heidarnejad, P.; Porkhial, S. Multi-objective optimization of a combined steam-organic Rankine cycle based on exergy and exergo-economic analysis for waste heat recovery application. Energy Convers. Manag.
**2016**, 127, 366–379. [Google Scholar] [CrossRef] - Ahmadi, G.; Toghraie, D.; Azimian, A.; Ali Akbari, O. Evaluation of synchronous execution of full repowering and solar assisting in a 200 MW steam power plant, a case study. Appl. Ther. Eng.
**2017**, 112, 111–123. [Google Scholar] [CrossRef] - Regulagadda, P.; Dincer, I.; Naterer, G.F. Exergy analysis of a thermal power plant with measured boiler and turbine losses. Appl. Ther. Eng.
**2010**, 30, 970–976. [Google Scholar] [CrossRef] - Taner, T.; Sivrioglu, M. Energy-exergy analysis and optimisation of a model sugar factory in Turkey. Energy
**2015**, 93, 641–654. [Google Scholar] [CrossRef] - Mrzljak, V.; Poljak, I.; Mrakovčić, T. Energy and exergy analysis of the turbo-generators and steam turbine for the main feed water pump drive on LNG carrier. Energy Convers. Manag.
**2017**, 140, 307–323. [Google Scholar] [CrossRef] - Ahmadi, G.; Toghraie, D.; Ali Akbari, O. Solar parallel feed water heating repowering of a steam power plant: A case study in Iran. Renew. Sustain. Energy Rev.
**2017**, 77, 474–485. [Google Scholar] [CrossRef] - Tan, H.; Shan, S.; Nie, Y.; Zhao, Q. A new boil-off gas re-liquefaction system for LNG carriers based on dual mixed refrigerant cycle. Cryogenics
**2018**, 92, 84–92. [Google Scholar] [CrossRef] - Mitrović, D.; Živković, D.; Laković, M.S. Energy and Exergy Analysis of a 348.5 MW Steam Power Plant. Energy Sources
**2010**, 32, 1016–1027. [Google Scholar] [CrossRef] - Lemmon, E.W.; Huber, M.L.; McLinden, M.O. Reference Fluid Thermodynamic and Transport Properties-REFPROP; Version 8.0, User’s Guide; NIST: Gaithersburg, MD, USA, 2007.
- Cengel, Y.; Boles, M. Thermodynamics an Engineering Approach, 8th ed.; McGraw-Hill Education: New York, NY, USA, 2015. [Google Scholar]
- Erdem, H.H.; Akkaya, A.V.; Cetin, B.; Dagdas, A.; Sevilgen, S.H.; Sahin, B.; Teke, I.; Gungor, C.; Atas, S. Comparative energetic and exergetic performance analyses for coal-fired thermal power plants in Turkey. Int. J. Ther. Sci.
**2009**, 48, 2179–2186. [Google Scholar] [CrossRef] - Moran, M.; Shapiro, H.; Boettner, D.D.; Bailey, M.B. Fundamentals of Engineering Thermodynamics, 7th ed.; John Wiley and Sons, Inc.: Hoboken, NJ, USA, 2011. [Google Scholar]
- Aljundi, I.H. Energy and exergy analysis of a steam power plant in Jordan. Appl. Ther. Eng.
**2009**, 29, 324–328. [Google Scholar] [CrossRef] - Kopac, M.; Hilalci, A. Effect of ambient temperature on the efficiency of the regenerative and reheat catalagzi power plant in Turkey. Appl. Ther. Eng.
**2007**, 27, 1377–1385. [Google Scholar] [CrossRef] - Li, J.; Wang, K.; Cheng, L. Experiment and optimization of a new kind once-through heat recovery steam generator (HRSG) based on analysis of exergy and economy. Appl. Ther. Eng.
**2017**, 120, 402–415. [Google Scholar] [CrossRef] - Hughes, A. Electric Motors and Drives—Fundamentals, Types and Applications, 3rd ed.; Elsevier Ltd.: Amsterdam, The Netherlands, 2006. [Google Scholar]
- Hafdhi, F.; Khir, T.; Ben Yahyia, A.; Ben Brahim, A. Energetic and exergetic analysis of a steam turbine power plant in an existing phosphoric acid factory. Energy Convers. Manag.
**2015**, 106, 1230–1241. [Google Scholar] [CrossRef] - Ameri, M.; Ahmadi, P.; Hamidi, A. Energy, exergy and exergoeconomic analysis of a steam power plant: A case study. Int. J. Energy Res.
**2009**, 33, 499–512. [Google Scholar] [CrossRef] - Kyma Shaft Power Meter: Continuous Measurement of Torque, Power and Revolutions. Available online: https://kyma.no/wp-content/uploads/2019/03/KPM-Kyma-Shaft-Power-Meter-brochure1.pdf (accessed on 27 October 2019).
- Yamatake JTD Series of Differential Pressure Transmitters. Available online: http://www.krtproduct.com/krt_Picture/sample/1_spare%20part/yamatake/Fi_ss01/SS2-DST100-0100.pdf (accessed on 27 October 2019).
- Greisinger Handheld Instrument: Temperature Infrared – Pt100 Measuring Probe. Available online: https://www.greisinger.de/files/upload/en/produkte/kat/k16_011_EN_oP.pdf (accessed on 27 October 2019).
- Yamatake JTG Series Of Pressure Transmitters. Available online: http://www.industriascontrolpro.com/fichat/SS2-DST400-0100.pdf (accessed on 27 October 2019).
- Fluke Wireless AC/DC Current Clamp. Available online: https://dam-assets.fluke.com/s3fs-public/a3002fc_cmeng0000.pdf (accessed on 27 October 2019).

**Figure 2.**The operating parameters of the forced draft fan with induction motor necessary for energy and exergy analyses.

**Figure 5.**Energy power input and output of the forced draft fan with respect to the steam system load.

**Figure 6.**The shares of electrical drive power and air flow stream in the energy power input of the forced draft fan.

**Figure 7.**Energy power loss and energy efficiency of the forced draft fan with respect to the steam system load.

**Figure 8.**Exergy power input and output of the forced draft fan with respect to the steam system load.

**Figure 9.**The shares of electrical drive power and air flow stream in the exergy power input of the forced draft fan.

**Figure 10.**Exergy destruction and exergy efficiency of the forced draft fan with respect to the steam system load.

Maximum Capacity | 1330 m^{3}/min |
---|---|

Maximum pressure increase | 5.6 kPa |

Suction temperature | 50 °C |

Maximum speed | 1788 min^{−1} |

Fan moment of inertia | 220 kg · m^{2} |

Inlet vane torque | 320 Nm |

Noise | 100 dB at 1.0 m (with anti-noise wall) |

Fan mass | 3100 kg |

Anti-noise wall mass | 240 kg |

3-Phase, Squirrel Cage Induction Motor | |||
---|---|---|---|

Load Characteristics: | Load (%) | Current (A) | Power Factor |

- | 50 | 181 | 0.71 |

75 | 238 | 0.8 | |

100 | 295 | 0.84 | |

Maximum rated output | 185 kW | - | |

Rated voltage | 440 V | ||

Rated frequency | 60 Hz | ||

Maximum rated speed | 1788 min^{−1} | ||

Maximum rated current | 295 A | ||

No-load current | 116 A | ||

Maximum nominal torque | 989 Nm | ||

Speed at minimum torque | 1350 min^{−1} | ||

Maximum starting time from hot | 18 s | ||

Maximum starting time from cold | 32 s | ||

The ambient temperature | 45 °C | ||

Cooling system | Self-ventilated | ||

Noise | 75 dB | ||

Moment of inertia | 3.5 kg · m^{2} | ||

Motor total mass | 970 kg |

Variable | Energy Balance [78] | Exergy Balance [79] | ||
---|---|---|---|---|

Equation | Equation Number | Equation | Equation Number | |

Power input | ${\dot{E}}_{\mathrm{en},\mathrm{IN}}={\dot{m}}_{1}\xb7{h}_{1}+P$ | (12) | ${\dot{E}}_{\mathrm{ex},\mathrm{IN}}={\dot{m}}_{1}\xb7{\epsilon}_{1}+P$ | (16) |

Power output | ${\dot{E}}_{\mathrm{en},\mathrm{OUT}}={\dot{m}}_{2}\xb7{h}_{2}$ | (13) | ${\dot{E}}_{\mathrm{ex},\mathrm{OUT}}={\dot{m}}_{2}\xb7{\epsilon}_{2}$ | (17) |

Power loss (destruction) | $\begin{array}{l}{\dot{E}}_{\mathrm{en},\mathrm{PL}}={\dot{E}}_{\mathrm{en},\mathrm{IN}}-{\dot{E}}_{\mathrm{en},\mathrm{OUT}}=\\ ={\dot{m}}_{1}\xb7{h}_{1}+P-{\dot{m}}_{2}\xb7{h}_{2}=\\ ={\dot{m}}_{1}\xb7({h}_{1}-{h}_{2})+P\end{array}$ | (14) | $\begin{array}{l}{\dot{E}}_{\mathrm{ex},\mathrm{D}}={\dot{E}}_{\mathrm{ex},\mathrm{IN}}-{\dot{E}}_{\mathrm{ex},\mathrm{OUT}}=\\ ={\dot{m}}_{1}\xb7{\epsilon}_{1}+P-{\dot{m}}_{2}\xb7{\epsilon}_{2}=\\ ={\dot{m}}_{1}\xb7({\epsilon}_{1}-{\epsilon}_{2})+P\end{array}$ | (18) |

Efficiency [35,80] | ${\eta}_{\mathrm{en}}=\frac{{\dot{m}}_{2}\xb7{h}_{2}-{\dot{m}}_{1}\xb7{h}_{1}}{P}$ | (15) | ${\eta}_{\mathrm{ex}}=\frac{{\dot{m}}_{2}\xb7{\epsilon}_{2}-{\dot{m}}_{1}\xb7{\epsilon}_{1}}{P}$ | (19) |

**Table 4.**Measurement data for air flow streams at fan inlet and outlet with regard to propeller speed.

Propulsion Propeller Speed (min ^{−1}) | Air at the Forced Draft Fan Inlet (1*) | Air at the Forced Draft Fan Outlet (2*) | ||||
---|---|---|---|---|---|---|

Temperature (°C) | Pressure (MPa)** | Mass Flow Rate (kg/h) | Temperature (°C) | Pressure (MPa) | Mass Flow Rate (kg/h) | |

0.00 | 50 | 0.1000 | 17277.75 | 55 | 0.10051 | 17277.75 |

25.58 | 42 | 40466.88 | 45 | 0.10154 | 40466.88 | |

34.33 | 42 | 40037.02 | 44 | 0.10155 | 40037.02 | |

41.78 | 42 | 39920.58 | 45 | 0.10149 | 39920.58 | |

53.50 | 44 | 45879.12 | 50 | 0.10228 | 45879.12 | |

56.65 | 40 | 44208.90 | 44 | 0.10107 | 44208.90 | |

61.45 | 39 | 50399.64 | 42 | 0.10154 | 50399.64 | |

62.52 | 40 | 50266.98 | 44 | 0.10144 | 50266.98 | |

63.55 | 39 | 51811.38 | 41 | 0.10165 | 51811.38 | |

65.10 | 39 | 53086.68 | 41 | 0.10177 | 53086.68 | |

66.08 | 39 | 54501.66 | 41 | 0.10187 | 54501.66 | |

67.68 | 39 | 54698.94 | 41 | 0.10197 | 54698.94 | |

68.66 | 39 | 57363.30 | 41 | 0.10214 | 57363.30 | |

69.49 | 39 | 58474.62 | 41 | 0.10218 | 58474.62 | |

70.37 | 39 | 58754.70 | 41 | 0.10222 | 58754.70 | |

71.03 | 39 | 57865.86 | 42 | 0.10225 | 57865.86 | |

73.09 | 39 | 60840.72 | 42 | 0.10258 | 60840.72 | |

74.59 | 39 | 64056.60 | 42 | 0.10292 | 64056.60 | |

76.56 | 39 | 67504.14 | 42 | 0.10345 | 67504.14 | |

78.41 | 39 | 69049.62 | 42 | 0.10368 | 69049.62 | |

79.46 | 39 | 71468.28 | 42 | 0.10406 | 71468.28 | |

80.44 | 39 | 72818.82 | 42 | 0.10438 | 72818.82 | |

81.49 | 39 | 72399.96 | 43 | 0.10429 | 72399.96 | |

82.88 | 39 | 73807.20 | 42 | 0.10464 | 73807.20 | |

83.00 | 39 | 74167.02 | 43 | 0.10469 | 74167.02 |

^{*}Air flow streams numeration refers to Figure 2;

^{**}Air pressure variations at the fan inlet are negligibly small.

**Table 5.**Measured stator current for the fan induction motor along with the calculated power factors (Equation (21)) for the entire range of steam system loads (propulsion propeller speeds).

Propulsion Propeller Speed (min^{−1}) | Current (A) | Power Factor (-) | Propulsion Propeller Speed (min^{−1}) | Current (A) | Power Factor (-) |
---|---|---|---|---|---|

0.00 | 162.6 | 0.670 | 69.49 | 236.0 | 0.798 |

25.58 | 203.6 | 0.752 | 70.37 | 236.5 | 0.798 |

34.33 | 202.8 | 0.750 | 71.03 | 234.9 | 0.796 |

41.78 | 202.6 | 0.750 | 73.09 | 240.2 | 0.802 |

53.50 | 214.4 | 0.769 | 74.59 | 245.7 | 0.808 |

56.65 | 210.2 | 0.762 | 76.56 | 251.4 | 0.814 |

61.45 | 221.4 | 0.779 | 78.41 | 253.8 | 0.816 |

62.52 | 221.4 | 0.779 | 79.46 | 257.6 | 0.819 |

63.55 | 224.0 | 0.783 | 80.44 | 259.6 | 0.821 |

65.10 | 226.3 | 0.786 | 81.49 | 259.0 | 0.821 |

66.08 | 228.9 | 0.789 | 82.88 | 261.1 | 0.822 |

67.68 | 229.3 | 0.789 | 83.00 | 261.6 | 0.823 |

68.66 | 234.0 | 0.795 | - | - | - |

**Table 6.**Main properties of air from [77] for energy and exergy analyses of the forced draft fan.

Air (N_{2} + O_{2} + Ar) | ||

Triple Point Temperature: | −213.4 °C | |

Boiling point temperature: | −194.25 °C | |

Acentric factor: | 0.0335 | |

Critical point characteristics | Temperature: | −140.62 °C |

Pressure: | 3.786 MPa | |

Density: | 342.68 kg/m^{3} | |

Molar mass: | 28.965 kg/kmol | |

Range of applicability | Minimum temperature: | −213.4 °C |

Maximum temperature: | 1726.9 °C | |

Maximum pressure: | 2000 MPa |

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Mrzljak, V.; Blecich, P.; Anđelić, N.; Lorencin, I.
Energy and Exergy Analyses of Forced Draft Fan for Marine Steam Propulsion System during Load Change. *J. Mar. Sci. Eng.* **2019**, *7*, 381.
https://doi.org/10.3390/jmse7110381

**AMA Style**

Mrzljak V, Blecich P, Anđelić N, Lorencin I.
Energy and Exergy Analyses of Forced Draft Fan for Marine Steam Propulsion System during Load Change. *Journal of Marine Science and Engineering*. 2019; 7(11):381.
https://doi.org/10.3390/jmse7110381

**Chicago/Turabian Style**

Mrzljak, Vedran, Paolo Blecich, Nikola Anđelić, and Ivan Lorencin.
2019. "Energy and Exergy Analyses of Forced Draft Fan for Marine Steam Propulsion System during Load Change" *Journal of Marine Science and Engineering* 7, no. 11: 381.
https://doi.org/10.3390/jmse7110381