Choke Point in Mini Expansion Device for the Development of Portable Vaccine Kit

Abstract

Vapor compression refrigeration system is substantial to human comfort and needs that contributes to the progress mainly in agriculture, food preservation and in medical application. One of the applications that this study focused on is the study of the choke points in mini expansion device for the development of portable vaccine carrier kit. This study utilized a vapor compression refrigeration system, and aims to improve the system operation of a small-scale vapor compression refrigeration system by using spirally-arranged capillary tubes with five(5) different hydraulic diameters, namely; 0.20mm, 0.25mm, 0.30mm, 0.35mm and 0.40mm. A 1/8 horsepower vapor compression refrigeration system of a water dispenser is used as an experimental rig that supply the required refrigerant flow on the spirally- arranged expansion device. Guitar strings are used to reduce the hydraulic diameter of the commercially available capillary tubes. With the inserted guitar strings, the five(5) different hydraulic diameters in this study would be connected to the experimental rig. The data gathering method is developed by using a data logger and the fabricated spirally-arranged capillary tubes connected to the experimental rig. The determination of its lengths of choke point and the behavior of the pressure drop is measured during the different trials used for every hydraulic diameter of the spirally-arranged capillary tube. The mathematical equation that correlates the hydraulic diameters of the capillary tubes and their corresponding choke points is represented by the equation y = -1,836.0x2 + 2,319.0x-1 - 1.7860, where y is the distance of the capillary tube choke point and x is the hydraulic diameter of the fabricated spirally-arranged capillary tubes. This equation correlates the hydraulic diameter of a capillary tube to its corresponding choke point length with a value of R2 = 0.9947.