Refrigerative Engineering Experiment Hello. My name is 김성준, a member of the sixth group. Today I’ll talk about Refrigerative Engineering Experiment. And than, let’s go to next slide. 나반 6조 20053416 김성준 20021559 김정래 20053421 양희돈 20031582 김용범                  20053420 서진수

CONTENTS 1 PURPOSE OF EXPERIMENT 2 ORGANIZATION & EQUIPMENTS 3 4 5 6 7 PURPOSE OF EXPERIMENT ORGANIZATION & EQUIPMENTS A CIRCUIT DIAGRAM METHOD OF EXPERIMENT ANALYSIS OF DATA COMPARISON CONCLUSION & CONSIDERATION Here is the table of contents Number one Number two …

1. PURPOSE OF EXPERIMENT 실제조작을 통하여 구성요소의 기능을 익히며, 압축기, 증기압축식 냉동장치의 기본구성요소를 이해하고, 실제조작을 통하여 구성요소의 기능을 익히며, 압축기, 응축기, 증발기를 순차적으로 시동하여 각 부분의 압력변화, 온도변화, 엔탈피 변화를 측정하여 냉동기 성능에 미치는 영향을 알아본다. The purpose of experiment is to understand basic knowledge of refrigerant equipment. And from actual experiment, measure the changes of Pressure, Temperature , and Enthalpy, from making variables of compressor, condenser, and evaporator.

2. ORGANIZATION This picture shows about the refrigerant diagram.  Then I'm going to show you some pictures of equipment at next five slides T1 - Compressor In T2 - Compressor Out T3 - Condenser In T4 - Condenser Out T5- Expansion Valve In T6 - Evaporator In T7 - Evaporator Out T8 - Room T9 - Out P1 - Compressor In P2 - Compressor Out P3 - Condenser Out P4 - Evaporator In

2. EQUIPMENTS STANDARD REFRIGERATOR This is the actual picture of equipment that we used for last 8 weeks. Followings are some main parts of this equipment.

2. EQUIPMENTS (Motor Compressor)는 표준 냉동 실험기계장치의 증발기에서 피 냉각 물체로부터 열을 흡수하여 증발한 저온, 저압의 기체냉매를 흡입 압축하여 압력을 상승시켜 분자간의 거리를 가깝게 하고, 온도를 상승시켜 상온의 응축기에서 쉽게 액화할 수 있도록 한다 (CONDENSOR)는 압축기에서 토출된 고온, 고압 냉매가스 열을 상온의 공기 중에 방출하여 응축시키는 작용을 한다. 압축기에서 토출된 고온고압의 기체 냉매를 주위의 공기나 냉각수에 열 교환시켜 기체냉매의 열을 방출하여 응축 액화하는 장치이다. 뜨거운 바람이 나오는 곳으로 응축기는 실외기 속에 있는 기기로서 압축기에서 나온 냉매가스가 냉매액체로 변하게 한다. Motor Compressor, Condensor

2. EQUIPMENTS 수동식 팽창밸브는 고온, 고압의 액체 냉매를 증발기에서 증발되기 쉽도록 저온, 저압의 액체 냉매로 단열 팽창시킨다. 응축 액화된 냉매는 좁은 곳을 통해서 급히 넓은 곳으로 방출되면 냉매는 압력으로부터 해방되어 증발하기 시작한다. 아울러 증발기에서 충분한 열을 흡수할 수 있도록 적정량을 조절해준다. 증발기는 냉동장치의 팽창밸브에서 온도와 압력이 떨어진 저온 저압의 액체냉매가 증발잠열을 흡수하여 냉각작용을 함으로써 냉동목적을 직접 달성하는 열교환 장치이며, 팽창밸브에서 나온 저온저압의 액 냉매를 피 냉각물체(동관 알루미늄 핀 공기)로부터 증발잠열을 흡수하여 냉동목적을 직접 달성시켜 주는 기기이다. Manual expansion valve, evaporator

3. A CIRCUIT DIAGRAM Experiment name : Practice of make-up direct circuit for low temperature (Temperature S/W) and low pressure (LPS) control with a standard refrigeration system kit. L1,L2 : Line Voltage Ry_b : Relay “b” contact N.F.B : No fuse circuit breaker COMP : compressor mortor PB : Push button YL : Yellow Lamp MC-a : MC “a” contact GL : Green Lamp PL : Power Lamp MC : Magnet contactor coil RY : Relay coil SV : Solenoid V/V EFM : Evaporator Fan Motor TC : Temperature control S/W RY_a : Relay “a” contact CFM : Condenser Fan Motor This is the circuit diagram used on my group’s experiment. (You can see them on the page 55 in our textbook)

4. METHOD OF EXPERIMENT 1) STANDARD EXPERIMENT 2) CONTROL THE EVAPORATOR DOOR ANGLE 20° 3) TURN HALF THE EXPANSION VALVE 4) TURN RIGHT ROUND THE EXPANSION VALVE These are the variables that we used on experiment of my group.

5. ANALYSIS (STANDARD) [1] TEMPERATURE standard condition up to 15 minutes, 20 degrees chamber opened from 15 to 30minutes, halfway locked expansion valve from 30 to 45minutes, and one rotation locked expansion valve from 45 to 60minutes. the temperature on standard condition goes uniform frequency.  Expansion valve takes effect on the rotation of the refrigerent transformation to vapor. And which play an important part on reducing temperature, and as the expansion valve is continually squeezened up, rotation of vapor is restrained. Then finally temperature of expansion valve gets higher. Now we know that we can control the temperature by Adjusting expansion valve.

5. ANALYSIS (STANDARD) [2] PRESSURE In the standard condition, it sustains same pressure during operation. Also when the door is opened, it sustains same pressure like the temperature situation. In addition, opened door means not only the increase of expansion valve's temperature, but also the increase of temperature.

5. ANALYSIS (STANDARD) [3] ENTHALPY The enthalpy increases as the expansion valve is continually locked in the standard condition, because the pressure and internal energy increased. The flow of refrigerant is blocked up, when the solenoid valve is closed. Then it decreases the pressure, also reduces enthalpy.

5. ANALYSIS (STANDARD) [5] COP Efficiency of performance declines when expansion valve is opened 20 degrees, compare to the COP (coefficient of performance) in standard condition. The efficiency is better, when expansion valve is squeezed up.

6. 결론 및 고찰 이번실험을 통해서 순차적으로 가동함으로써 각 장치가 가지는 역할과 각 해당지점에서의 온도 및 압력, 엔탈피,열교환량, COP등에 대해서 알아볼 수 있었다. 증발기 도어 20° 오픈 상태의 실험은 실패 도어를 통해 대기로 빠져 나가기에 냉방률이 떨어졌다 COP의 변화가 급격해 진 이유는 고온부에세 교환되는 열량이 적어지고 저온부에서 교환되는 열량이 많아졌기 때문이다. On this lab, we have set many variables (such as COMP_IN_OUT, COND_IN_OUT, EVA_IN_OUT), then plotted the chart and analyzed them. From this experiment in this class, we’ve got known basic parts of equipment and how they functions…… depends on the Temp, Pressure, Enthalpy, and some other things. as seen on the graph, COP decreases rapidly as time flows. then we realized that there was something wrong with our experiment. however, we could find out other answer for that. When the evaporator door was opened, there was no changes at all, for a whole thing. It's as same as the situation that we operates air conditioner with the windows opened at the same time. In other words, air-conditioning efficiency in the room decreases as the cold air goes out of the window. COP rapidly increases, as the amount of heat value on the upper part decreases, and the amount of heat value on the lower part increases.

7. 참고자료 [1] 김철수 외 1인, “냉동공학이론”, KTEng, 2006 [2] 김성철 외 4인, “공조냉동실험실습”, 선학출판사, 2002 [3] 민만기 외 4인, “공기조화 및 냉동”, 사이텍미디어, 2002 [4] 안석규, “고주파 유도가열기를 사용한 Rapid Prototyping 장비의 개발”, 숭실대학교 석사학위 논문, 2006 [5] KTEng(www.KTEng.com) These are some of references that we used.

감 사 합 니 다 I think this is the end of my presentation. Thank you for listening. Do you have any questions.?