Thamir K. Salim

Bio: Thamir K. Salim is an academic researcher from University of Tikrit. The author has contributed to research in topics: Cooling capacity. The author has an hindex of 1, co-authored 1 publications receiving 9 citations.

The Effect of the Capillary Tube Coil Number on the Refrigeration System Performance

Abstract: The capillary tube performance for (R134a) is experimentally investigated. The experimental setup is a real vapor compression refrigeration system. All properties of the refrigeration system are measured for various mass flow rate from (13 – 23 kg/hr) and capillary tube coil number (0-4) with fixed length (150 cm) and capillary diameter (2.5mm). The results showed that the theoretical compression power increases by (65.8 %) as the condenser temperature increases by (2.71%), also the theoretical compression power decreases by (10.3 %) as the capillary tube coil number increases. The study shows also that the cooling capacity increases by (65.3%) as the evaporator temperature increases by (8.4 %), and the cooling capacity increases by (1.6%)as the capillary tube coil number increases in the range (0-4). The coefficient of performance decreases by (43.4 %), as the mass flow rate increases by (76.9%), also the coefficient of performance increases by (13.51 %) as the capillary tube coil number increases in the range (0-4). Through this study, it was found that the best coil number in refrigeration cycle at the lowest mass flow rate (31 Kg/hr) and at high mass flow rate (23 Kg/hr) is (coil number = 4), this will give the highest performance, cooling capacity and lowest theoretical compression power.

An experimental study of the Effect of capillary tube diameter and configuration on the performance of a simple vapour compression refrigeration system

Abstract: The study of the expansion device in the simple vapour compression refrigeration system is necessary in order to understand the parameters which can enhance the overall performance of the system. The experimental study was done on the capillary tubes of 31 gauge, 36 gauge and 40 gauge and each test section was studied with three distinct configurations i.e. helical coiled, straight coiled and serpentine coiled configuration. The effect of the configuration and the capillary tube diameter on the overall performance of the system was studied. The findings of the experimental study revealed that the mass flow rate is maximum for the straight configuration and is least for the helical coiled configuration. The refrigeration effect was found to be maximum for the helical coiled configuration and was found to be least for straight coiled configuration. The compressor work was found to reduce as the load was increased on the system. Decreasing the capillary tube diameter increased the mass flow rate in the system and decreased the refrigeration effect produced.

Effect of capillary tube on the performance of a simple vapour compression refrigeration system

Abstract: It is essential to study the effect of capillary tube geometry on the performance of refrigeration systems. The literature review focuses on the effect that geometrical parameters like capillary tube length, bore diameter, coil pitch, number of twist and twisted angle have on the pressure drop, coefficient of performance (COP) and mass flow rate of the system. These parameters can be further studied using physical models and mathematical modeling concepts. The parameters stated above can be further optimized in order to enhance the performance of the refrigeration system.

Effect of Capillary Tube Length and Refrigerant Charge on the Performance of Domestic Refrigerator with R12 and R600a

Abstract: In this work, the thermodynamic performance of a domestic refrigerator was experimentally studied by simultaneously varying the refrigerant charge (mr) and the capillary tube length (L). The potential of replacing R12 by R600a was also investigated. The test rig for the experiment was a vapor compression refrigerator designed to work with R12. The enthalpy of the refrigerants R600a and R12 for each data set for the experimental conditions were obtained by using REFPROP software (version 9.0). The results show that the design temperature of -120C (according to ISO - 8187 standard) and pull – down time of 135 minutes are achieved by using 60g of R600a with L= 1.2m and 1.5m. For R12, the design temperature is achieved at pull – down time of 165 minutes with mr = 40g and L = 0.9m. The appropriate combination of L and mr for R600a to be used as a drop-in refrigerant for R12 is found to be 1.5m and 60g on the basis of power consumption per day, pull-down time and COP, whereas by considering the cooling capacity, it is 0.9 m and 60g. The cooling capacity of R600a was about 9.18% higher than that of R12, the power consumed by R600a was about 24 % lower than that of R12 and the COP of R600a was about 6.3% higher than that of R12. In conclusion, the proposed R600a seems to be an appropriate long-term candidate to replace R-12 in the existing refrigerator in terms of power consumption, cooling capacity and COP.

A comparative study on the performance of the domestic refrigerator using r600a and lpg with varying refrigerant charge and capillary tube length

Abstract: A comparative experimental study on the performance of a domestic refrigerator using R600A and LPG with a varying refrigerant charge (wr) and capillary tube length (L) was carried out. The enthalpy of the refrigerants R600A and LPG for each data set for the experimental conditions were obtained by using REFPROP soft ware (version 9.0). The results show that the design temperature and pull-down time set by ISO for a small refrigerator are achieved earlier using refrigerant charge 60 g of LPG with a 1.5 m capillary tube length. The highest COP (4.8) was obtained using 60-g charge of LPG with L of 1.5-m. The average COP obtained using LPG was 1.14% higher than that of R600A. Based on the result of electric power consumption, R600A off ered lowest power consumption. The compressor consumed 20% less power compared to LPG in the system. The system performed best with LPG in terms of COP and cooling capacity, while in terms of power consumption R600A performed best.

Simulation of Flow Characteristics of Refrigerant inside Adiabatic Straight Capillary Tube

Abstract: In the present investigation, an attempt is made to develop mathematical model to determine the flow characteristics of refrigerant inside a straight capillary tube for adiabatic flow conditions. The proposed model can predict the length of the adiabatic straight capillary tube for a given mass flow rate. In the present study R-12 has been used as a working fluid inside the straight capillary tube of diameter 1.17 mm and 1.41 mm and used the same model to study the flow characteristics of refrigerant in ANSYS CFX software. Finally the results of mathematical model are valuated with ANSYS CFX and the results are found to be in fair agreement. Key word: adiabatic straight capillary tube, refrigerant R12, ICEM, CFD AND ANSYS CFX.