표제지

Abstract

목차

제1장 서론 15

1.1. 연구 배경 및 목적 15

1.2. 연구 방법 및 내용 17

1.2.1. 평가특성치의 선정 17

1.2.2. 시료 및 실험 조건 17

제2장 이론적 배경 20

2.1. 고순도 압축공기 제조시스템 개요 20

2.1.1. 고순도 압축공기 제조시스템의 구성 요소 20

2.1.2. Air Compressor(공기압축기)의 종류 21

2.1.3. Air Compressor의 구조 24

2.1.4. 고순도 압축공기의 압력 및 노점 32

2.2. 주요설비의 작동 원리 35

2.2.1. Turbo Air Compressor 35

2.2.2. 냉동식 Dryer 39

2.2.3. 흡착식 Dryer 42

2.3. 부대설비의 종류 및 기능 47

2.3.1. Receiver Tank 47

2.3.2. After Cooler 50

2.3.3. Filter 52

2.3.4. 냉각수 Pump 54

2.3.5. Cooling Tower(냉각탑) 57

2.3.6. 응축수 Drain Trap 62

2.4. 고순도 압축공기 제조시스템의 소비 전력 65

2.4.1. Air Compressor의 소비전력 65

2.4.2. Air Compressor의 소비전력 저감 67

2.5. 고순도 압축공기 제조시스템에서의 에너지절감에 대한 선행연구 70

2.5.1. 국내·외 연구동향 70

제3장 연구 방법 79

3.1. "A"사의 클린룸 현황 79

3.1.1. 클린룸의 청정도 관리 79

3.1.2. 클린룸의 공조 Process 80

3.2. "A"사의 고순도 압축공기 제조시스템의 구성 현황 81

3.3. "A"사의 고순도 압축공기 제조시스템의 전력 소비 현황 83

3.4. 흡착식 Dryer의 주요 인자 84

3.4.1. 재생 압력 84

3.4.2. Heating 온도 85

3.4.3. 재생시간 86

3.5. 흡착식 Dryer의 주요 운전 방식 87

3.5.1. Time 운전 87

3.5.2. 노점 운전 89

3.6. 실험 환경 93

3.6.1. 고순도 압축공기의 품질 수준 93

3.6.2. 실험 측정 계측기 94

3.6.3. 흡착식 Dryer Specification 96

3.6.4. Monitoring 시스템 구축 97

3.6.5. 실험 전제 조건 99

제4장 결과 및 고찰 101

4.1. Time 운전에 대한 실험 결과 101

4.1.1. 재생 압력 변경 실험 102

4.1.2. Heating 온도 변경 실험 107

4.1.3. Time 운전 실험 114

4.2. 노점운전에 대한 실험 결과 121

4.2.1. 노점 운전 실험 121

4.2.2. Delay Time 적용 실험 123

4.2.3. Delay Time & PSR 적용 실험 131

제5장 결론 137

참고문헌 142

Table 2-1. International ISO Standards, Notification as specified in... 34

Table 2-2. Dew point temperature by pressure 35

Table 2-3. Physical characteristic for each absorbent 45

Table 2-4. Filter specification of purifying compressed air... 54

Table 2-5. Conversion coefficient of standard chilling ability in Cooling... 61

Table 3-1. Clean class management standard of clean room 80

Table 3-2. Design specification of adsorption type dryer 97

Table 4-1. Energy expense by regeneration pressure 106

Table 4-2. Energy expense by heating temperature 112

Table 4-3. Purge temperature at 200~210°C, H6_C6 117

Table 4-4. Purge temperature at 210~220°C, H6_C6 117

Table 4-5. Energy expense by regeneration time (12hr, 14hr, 16hr) 120

Table 4-6. Energy expense by delay time application test 130

Table 4-7. Energy expense by delay time & PSR application test 134

Table 4-8. Optimized energy saving operation of adsorption dryer 136

Fig. 1-1. The flow chart of this study 19

Fig. 2-1. Composition and flow of purifying ccmpressed air system 21

Fig. 2-2. Types of wide use air compressor 22

Fig. 2-3. Classification by flow direction of turbo air compressor 24

Fig. 2-4. Compression stroke of reciprocating type air compressor 25

Fig. 2-5. Compression stroke of rotary type air compressor 26

Fig. 2-6. Structure of oil free air compressor 27

Fig. 2-7. Compression flow of oil free air compressor 28

Fig. 2-8. Structure of oil injection air compressor 29

Fig. 2-9. Compression flow of oil injection air compressor 30

Fig. 2-10. Structure of turbo type air compressor 32

Fig. 2-11. Internal structure of turbo compressor 36

Fig. 2-12. Air flow of turbo compressor 38

Fig. 2-13. Air flow of refrigeration type dryer 41

Fig. 2-14. Adsorption Process 43

Fig. 2-15. Heated Type Dryer and Air Flow 44

Fig. 2-16. Receiver Tank 48

Fig. 2-17. Capacity and air consumption of receiver tank 49

Fig. 2-18. Air flow of water chilling type after cooler 51

Fig. 2-19. Filter installation cases of purifying compressed air... 52

Fig. 2-20. Types of centrifugal pump 55

Fig. 2-21. Circulation flow of cooling water in purifying compressed air... 57

Fig. 2-22. Cooling characteristic of cooling tower 58

Fig. 2-23. Classification by contact direction of air and water 59

Fig. 2-24. Condensed water drain trap installation cases from... 63

Fig. 2-25. Performance principle and structure of ccndensed water drain... 64

Fig. 2-26. Power consumption and content of compressor unit 66

Fig. 3-1. Air handling unit process in clean room 81

Fig. 3-2. Distribution diagram of purifying compressed air system in "A"... 82

Fig. 3-3. Power usage status in "A" company (accumulated by... 83

Fig. 3-4. Power consumption for each purifying compressed air... 84

Fig. 3-5. Operating characteristic of adsorption type dryer 86

Fig. 3-6. Time based operation 88

Fig. 3-7. Dew point based operation 90

Fig. 3-8. Delay time application test 91

Fig. 3-9. Delay time & PSR application test 92

Fig. 3-10. Particle Gauge 95

Fig. 3-11. Dew point gauge 96

Fig. 3-12. Installation monitoring system about dryer in "A" company 98

Fig. 3-13. Extraction point of major factor from purifying compressed air... 99

Fig. 4-1. Control panel of adsorption type air dryer 101

Fig. 4-2. Dew point temperature by pressure 102

Fig. 4-3. Dew point temperature by pressure 103

Fig. 4-4. Upper tower temperature purge volume by pressure 104

Fig. 4-5. Power consumption by pressure 105

Fig. 4-6. Dew point by heating temperature 107

Fig. 4-7. Dew point by heating temperature 108

Fig. 4-8. Purge volume by heating temperature 108

Fig. 4-9. Upper tower temperature by heating temperature 109

Fig. 4-10. Purge temperature by heating temperature 109

Fig. 4-11. Power consumption by heating temperature 110

Fig. 4-12. temperature of heating section by heating temperature 110

Fig. 4-13. temperature of cooling section by heating temperature 111

Fig. 4-14. System performance @H6_C6(heating temperature 200~210°C) 115

Fig. 4-15. System performance @H6_C6(heating temperature 210~220°C) 115

Fig. 4-16. Dew point purge vol. trend @H6_C6(heating temperature... 116

Fig. 4-17. Dew point purge vol. trend @H6_C6(heating temperature... 116

Fig. 4-18. Dew point trend by regeneration time(14hr, 16hr) 118

Fig. 4-19. System performance @H7_C7(heating temperature 200~210°C) 119

Fig. 4-20. System performance @H8_C8(heating temperature 200~210°C) 119

Fig. 4-21. Dew point of dew point operation @H7_C7, 200~210°C, 2.5 bar 122

Fig. 4-22. Dew point of dew point operation @H8_C8, 200~210°C, 2.5 bar 122

Fig. 4-23. Temperature of regeneration, upper tower, lower tower,... 124

Fig. 4-24. Temperature of regeneration, upper tower, lower tower, purge.... 124

Fig. 4-25. Upper tower, purge temperature by purge temperature... 125

Fig. 4-26. Dew point, purge temperature @H12, C12 operation, lower... 126

Fig. 4-27. Dew point, purge temperature @H14, C14 operation, lower... 126

Fig. 4-28. Upper tower temperature by pressure 127

Fig. 4-29. Heating temperature, Purge temperature by pressure 128

Fig. 4-30. Lower tower temperature by pressure 129

Fig. 4-31. Dew point of PSR test 131

Fig. 4-32. Heating, Purge temperature of PSR test 132

Fig. 4-33. Purge volume of PSR test 132

Fig. 4-34. Exit temperature to refrigerator from upper tower temperature... 133

Fig. 4-35. Optimization concept of both sides extension of supply and... 135

 This study is about an operation method and a proposal to save energy from the adsorption dryer in the process of purifying compressed air(ISO 8573-1, class 1)which is required for a clean room production site in "A" company. The adsorption dryer is a facility which removes the moisture in the air; meanwhile, consuming a lot of energy. Energy consumption of the adsorption dryer can be lowered by altering the operating conditions: time, pressure, temperature, and so on.

Therefore, based on the current operating experiences of the adsorption dryer in the CDA (clean and dried air) production system, I have searched for the operating method that saves the most energy by varying the operating conditions of the dryer while comparing the energy usage of each alteration. Doing this is very risky as the system supplies CDA in the mass production process. Therefore I approached this experiment with a sequential method, which changes each factor and searches for the best condition one factor at a time rather than just conducting a complex simultaneous experiment.

In testing the regenerating pressure, all four conditions(2.5, 2.7, 3.0, 3.3 bar)were satisfied below -80℃ of the dew point temperature. Among them, the dew point temperature and regenerating cost were the lowest at a 2.5 bar. During the heating temperature assessment, all four conditions (200~210, 210~220, 220~230, 230~240℃) were met at the dew point temperature. The regenerating cost was the most efficient at 200~210℃.

For the regenerating time evaluation, I conducted tests under three conditions(12, 14, 16 hours). The result was that 14 hours of regenerating time was more economical than 16 hours. However, anything under 12 hours of regenerating time was insufficient for regeneration. Through these time operating tests, I used a 2.5 bar, 200~210℃ and 14 hours in the regeneration process as the basic conditions of improvement.

Under the dew point operating tests, I set a -80℃ dew point temperature as the tower exchanging condition and conducted tests with a 14 and 16 hour regenerating time while keeping all other conditions of improvement the same. As a result, I discovered that there is a limited supplying time of 24 hours. Therefore, managing the safety device is necessary to prevent an error in the quality of CDA.

I applied the delay time of 8 hours after finishing the 14 hours of regeneration under the basic conditions of improvement. As a result, the delay time function worked. However, the purge temperature was 50℃ lower than the reference temperature, that is because the regenerating time of 14 hours was too short to dry all of the moisture, which was absorbed in 22 hours. Therefore, I continued to search for the needed regenerating time.

To find the regenerating time necessary for the limited supply time of 24 hours. I applied a PSR (Purge Stop Regeneration) function with a heating and cooling temperature of 100℃ and 40℃ respectfully, as the purge temperature which served as the reference to judge the finished regeneration. As a result, the PSR function properly operated and the regeneration was completed in 16.5 hours. On these conditions, I decided this was the necessary time for successful regeneration.

Under the condition of a 16 hour regenerating time, a 6 hour delay time (with 22 hours of supply time), with a purge temperature of 100℃ heating and 40℃ cooling, I conducted the next test by changing the pressure and temperature. As a result, all of them satisfied the mass production standard. I also confirmed that operations were achieved within a heating time of 10 hours and a cooling time of 6 hours in the regenerating time process.

Based on these results, I further experimented with the application of a delay time and the PSR function by changing the temperature and pressure under the common conditions of a regenerating time of 22 hours (heating 11, cooling 11), a delay time 2 hours (24 hours of supply time), and a purge temperature of 100℃ heating and 30℃ cooling. As a result, the dew point temperature, heating temperature, and purge temperature all satisfied the supply conditions. Furthermore, I found that the regenerating cost was the most efficient in the 2.5 bar of regenerating pressure and a heating temperature of 200~210℃.

This result leads me to conclude that 18% of the energy used can be saved compared to the time operating method currently in use; thus, these conditions were adopted as the new operation method for the adsorption dryer in the process of purifying compressed air at "A" company and have been in operation since September of 2015. I believe this study would improve the performance of the current operation method of the adsorption dryer by saving energy and can be used as basic data for other facilities as well.