Title Page
Abstract
Contents
Nomenclature 12
1. Introduction 13
2. Experimental Methods 16
2.1. Spray Characteristic Measurements 16
2.1.1. Illuminating the spray temporal development 16
2.1.2. Evaluating droplet sizes of water spray 18
2.2. Boiler system thermodynamic analysis 19
2.2.1. Operation of a WHRB with water spray injection 19
2.2.2. Boiler system global reaction equation 21
2.2.3. Thermodynamic properties 21
2.2.4. Mass and energy balance in the recovery HE-X and estimation of adequate injected water mass rate. 22
2.2.5. Heat exchanger performance index calculation 24
2.2.6. Boiler efficiency analysis 26
2.3. Calculation of NOx formation[이미지참조] 29
2.4. WHRB Test 30
2.4.1. Boiler experimental setup 30
2.5. Experimental Conditions 32
3. Results and Discussion 34
3.1. Effects of Injection Frequency on Water Spray Characteristics 34
3.1.1. Axial-plane spray structure 34
3.1.2. Spray structure in the cross-sectional plane 37
3.1.3. Average droplet diameter of the water spray 41
3.2. WHRB Performance with High-Frequency Injection 42
3.2.1. Results of boiler performance testing 42
3.2.2. Thermodynamic analysis of the boiler test results 49
4. Conclusion 57
References 58
Figure 1. Diagram of the Mie-Scattering experimental setup visualizing the spray structure of the water injection in the: a) axial plane and b) cross-sectional plane. 17
Figure 2. Diagram of the LDM test setup. 18
Figure 3. Schematic visualizing the operation of a WHRB/WI. 20
Figure 4. Thermodynamic schematic highlighting the heat input section of the energy conservation equation. 23
Figure 5. Thermodynamic schematic highlighting the heat exchanger performance index variables, TA-Xi, TA-Xo, and TG-Xi.[이미지참조] 25
Figure 6. Thermodynamic schematic of the boiler system's heat input variables QHHV, QA-xi, and QIW-X.[이미지참조] 27
Figure 7. Thermodynamic schematic of the boiler system's points of heat loss, QG-Xo, QCW-AX, QCW-C, and QCW-GX.[이미지참조] 28
Figure 8. Schematic of the test setup for the experimental boiler showing the positions of the sensors measuring the temperature (T) and relative humidity (ϒ) for the air intake and exhaust... 31
Figure 9. Diagram depicting the comparison of each injection frequency's pulse width. 35
Figure 10. Images visualizing the impact the injection frequency has on water spray characteristics in the axial plane (Images begin 6.5ms after the beginning of the 50Hz injection... 36
Figure 11. Results and analysis of the spray development in the cross-sectional plane as the injection frequencies of 50Hz. 100Hz, and 200Hz are tested. Part a) shows the cross-sectional... 38
Figure 12. Shows the analysis of the cross-sectional imaging results pertaining to the changes in spray structure as the injection frequency is increased: mean pixel intensity for each image during... 40
Figure 13. SMD of the water injection in the central spray region with an axial distance of 150mm from the nozzle exit for each injection frequency tested. 41
Figure 14. Impact of the injection frequency on the: a) evaporation rate of the water spray & b) temperature of the exhaust gas post waste heat recovery (total mass flow rate: 50 g/min, injection... 43
Figure 15. a) Effect of injection frequency on the thermal efficiency of the experimental boiler & b) the NOx emissions from the flu gases after the waste heat recovery process of the experimental...[이미지참조] 46
Figure 16. a) Shows the calculated adiabatic flame temperature as the evaporation rate of the water spray increases. b) Depicts the NOx produced because of the computed adiabatic flame temperature.[이미지참조] 48
Figure 17. Boiler schematic illustrating the parameters used in the MATLAB model for analyzing the experimental results. 50
Figure 18. MATLAB thermodynamic analysis of boiler test results without water injection. 53
Figure 19. MATLAB thermodynamic analysis of boiler test results for 50 Hz water injection frequency. 54
Figure 20. MATLAB thermodynamic analysis of boiler test results for 100 Hz water injection frequency. 55
Figure 21. MATLAB thermodynamic analysis of boiler test results for 200Hz water injection frequency. 56