![]() ![]() The latent process of the condenser must remove the same energy as the evaporator, the condenser also must make at least 2.7 pounds of liquid per cycle in its cycle to keep the balance of energy happy. 005, now divide the volume by the specific volume. Two foot of line multiplied by the internal volume, 2 X. Moving to the high-pressure side of the refrigerant circuit we address the small amount of discharge line the same way as the suction line except we use the specific volume at 256 degrees, which is. So, the low side of the system has, 2.75 +. To know how much refrigerant is in the line, divide the volume of the line by the specific volume of the refrigerant at 55 degrees. The line is 50-foot-long, so the entire volume of the suction line is. Information about tube dimensions and applications of copper tubing: Next determine how much refrigerant is in the suction line. The total evaporator charge during operation is 2.75 pounds. 0686, would have the equivalent volume of 127 foot of 3/8 copper line. 0343 multiplied by the vapor density, 1.6421, or. The amount of refrigerant gas would then be. The gas and liquid are at the same temperature and pressure so the relation (P1 X V1)/T1 = (P2 X V2)/T2, The P & T’s cancel out and you have V1 = V2, so the gas is approximately occupying. It’s safe to say that the amount of space the gas occupies must be minimized because the gas doesn’t remove any heat to speak of. We know 30% of that is liquid and the other 70% is gas occupying the remaining space in the evaporator. 012738 cubic foot per pound so, the liquid occupies. The specific volume of the refrigerant liquid in the evaporator is. 3 X 9 = 2.7 pounds of liquid at any moment in the evaporator. The energy can only be removed by boiling liquid refrigerant so, if 30 percent of the content is liquid, only 30 percent of the 9 pounds per minute is in the evaporator, or. 296 percent, round up to 30%, is liquid at any given moment in the evaporator. The total liquid available is the area under the triangle which is found by ½ X (1-.23) X. Below is a sketch of the system, and marked in red are the points in the system that are 100% liquid. The refrigerant is moving at a given velocity so that 9 pounds gets through evaporator and the condenser in one minute, not all at once. ![]() Now, the dynamic condition of the refrigerant isn’t all liquid of nine pounds. Divide 600 by 66.11 and you get the refrigerant flow of 600 / 66.11 = 9 pounds per minute of refrigerant flow required to meet the capacity. The net refrigeration effect, or evaporator cooling, is the difference in specific enthalpy of the evaporator, or, 175.41- 109.3 = 66.11 Btu per pound of refrigerant. (There is a volume associated with suction gas cooled compressors but it relatively small compared to system charge.) There are no other components that add volume to the system. The discharge line is ¾” and 2-foot long. This is a 3-ton split system with a 3/8” liquid line and a ¾” suction line 50-foot long. The temperature lines are in 10 degree increments. You can easily access the high quality refrigerant chart by clicking on the refrigerants listed in the table.The table is the data used to make the plot. This article is a continuation of our older article, which was well received by users, so we decided to update the P-H Diagram list and provide you with a more complete list of the world's commercial refrigerants. Also in the superheated region, the constant-entropy lines incline sharply upward, and constant volume lines are flatter. In two-phase region, the constant temperature lines are horizontal. At higher temperatures, they are curves near the saturated liquid line. The constant-temperature lines are nearly vertical in the sub-cooled liquid region. In the two-phase region, the constant-dryness-fraction quality line subdivides the mixture of vapor and liquid. The saturated vapor line separates this two-phase region from the superheated vapor. The saturated liquid line separates the sub-cooled liquid from the two-phase region in which vapor and liquid refrigerants coexist. P-h enthalpy diagram consist of following lines:Įnthalpy “ h” is along x-axis and absolute pressure “ p” is along the y-axis, both expressed in logarithmic scale. ![]()
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