Modeling on designs parameters of plate fin and tube condenser and direct expansion evaporator using R-407C

مقدم أطروحة جامعية

Said, Ranj Sirwan Abd Allah

الجامعة

الجامعة التكنولوجية

الكلية

قسم هندسة المكائن و المعدات

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2006

الملخص الإنجليزي

A computer program is developed to study and simulate the working and performance of an air conditioning system which consists of four main parts compressor, condenser, capillary tube and evaporator), using two types of refrigerant R-22 and R-407C.

The study covered the effect of varying design parameters 0f pirate-Fin-and-Tube heat exchanger working as condenser and direct expansion evaporator in the system.

Loss and efficiency model is used to simulate the compressor.

Element by element scheme is used to simulate the condenser, evaporator and capillary tube.

Elements by elements methods are used to simulate the heat transfer coefficient and the refrigerant properties the variation in air side heat transfer coefficient and aid-temperature from row to row is considered.

The design parameters can be classified into operating and configuration parameters.

The studied operating parameters are facing air velocity over condenser and evaporator and degree of super heat of refrigerant.

The configuration parameters varied are tube diameter, transverse tube spacing, longitudinal tube spacing and fin per inch.

To accomplish the requirement of this study, a rig was built in the Air-Conditioning and refrigeration lab.

The experimental rig is a split model Climatrol-Air-Conditioner 2 Ton capacity using R-22.

The indoor unit is installed in thermally isolated and controlled air temperature by using constant internal load of 7 kW.

The outer unit is installed in the outside and it is conducted to a duct used to control the input air temperature to the condenser.

The test shows good agreement with theoretical program for different ambient temperature.

The maximum deviation in COP was 7.1 %.

The theoretical results show that COP for the system of R-407C is less by (5 %-20 %) of that of R-22 for the range of ambient temperature of (35-47C°) respectively.

the study has found that the optimum operating parameters in both condenser and evaporator is 3m / s & 2m / s air velocity and that the COP decrease with increasing the degree of super heat.

The optimum configuration parameters are : 7 9 mm tube diameter (for both condenser and evaporator) (Longitudinal tube spacing / outer tube diameter) is 2.25 & 1.6 for condenser and evaporator Fin pitch 18 and 20 fin / inch (for condenser and evaporator) (Transverse tube spacing / outer tube diameter) = 2.75 for evaporator only.

التخصصات الرئيسية

الهندسة الميكانيكية

الموضوعات

• تكييف الهواء

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-306224