Reciprocating compressor calculation problems – take a look everyone
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A single-stage reciprocating piston compressor for methane gas compression produced by Shandong Shida Technology Co., Ltd.; the inlet pressure is 16.8 bar (absolute), and the inlet temperature is 25°C℃； The outlet pressure is 43 bar (absolute), and the outlet temperature is 90°C. The cylinder diameter D is 200 mm, the stroke S is 320 mm, and the relative clearance is 0.14. The compressor is double-acting, with a piston rod diameter of d equal to 70 mm. The compressor’s rotation speed is n = 500 rpm. Given that the pseudo-critical temperature of methane gas is 210 K, the pseudo-critical pressure is 45.5 bar, and the adiabatic index of temperature is 1.316, determine the volume coefficient, displacement volume, exhaust temperature, and shaft power of this compressor. Based on the given conditions and literature reviews, the value is 0.96, another value is 0.95, and yet another value is 1.278. The temperature coefficient is 0.96, the leakage coefficient is 0.94, and the pressure coefficient is 0.97. The value taken as 0.93; calculations were performed using equations (14), (13), (15), and (10), and the results are shown in Table 2. Table 2: Characteristic parameters of methane gas compressors. Characteristic parameters: volumetric efficiency, discharge volume/m3/min, exhaust temperature/k, shaft power/kW. Parameter values: 0.845, 6.99373268. How is the discharge volume of 6.99 m3/min calculated?
The displacement is related to the volume coefficient, temperature coefficient, leakage coefficient, pressure coefficient, the cylinder stroke volume per stage, and the compressor speed: (0.1×0.1×3.14 – 0.035×0.035×3.14) × 2 × 0.32 × 500. The temperature coefficient is 0.96, the leakage coefficient is 0.94, the pressure coefficient is 0.97, and the volume coefficient is 0.845; this results in 6.5 m3/min. I’m not sure if this calculation is correct
There should be data on the piston stroke.
The original poster doubled the volume of the piston rod; for a double-acting cylinder, you only need to calculate the piston rod on one side. It is normal for the calculated values to be higher than the labeled values; typical devices have a design margin of 5%–15%.
{(0.1×0.1×3.14-0.035×0.035×3.14) + (0.1×0.1×3.14)} × 0.32 × 500; the temperature coefficient is 0.96, the leakage coefficient is 0.94, and the pressure coefficient is 0.97. Therefore, 0.845 = 6.976 m3/min. So, for different gases, as well as different inlet temperatures and pressures, how can one determine the values of the temperature coefficient, pressure coefficient, leakage coefficient, and volume coefficient?
So, for different gases, and different intake temperatures and pressures, how can one determine the temperature coefficient, pressure coefficient, leakage coefficient, and volume coefficient?
Can http://bbs.hcbbs.com/thread-1427354-1-1.html answer this question?