9
Terminology
Units of Measure: PSI PSIG PSIA MMCFD MMSCFD 60°F = pounds per square inch = pounds per square inch gauge = pounds per square inch absolute = gauge + atmospheric pressure = million cubic feet per day = million cubic feet per day @ the standard conditions of 14.65psia &
3
Terminology 术语
Ratio of Compression (RC) 压缩比 RC = 排气压力(Pd)psig + 14.7 = ??? psia 吸气压力(Ps)psig + 14.7 = ??? psia
注: 当计算压缩比时，必须要考虑海拔和大气压力。
4
Terminology 术语
11
In-H2O
Terminology
Temperature Scales:
Temperature = A measure of molecular energy… the higher the temperature the more molecular energy. Degrees Fahrenheit (°F) = Temperature scale where, at sea level, the freezing point of water is 32° & the boiling point is 212°. The distance between these two points is 180°.
HP = 21 X 4.2 X 2 X 1 HP = 176.4
19
Configuration
V
Configuration
Inline
Horizontal Opposed
Configuration
Separable Engine
20
Terminology
Separable Compressor Frame
Swept Volume HE = Area of Piston X Stroke in Inches Swept Volume CE = (Area of Piston - Area of Rod) X Stroke in Inches Total Swept Volume = (2 X Area of Piston - Area of Rod) X Stroke In Inches
10
Terminology
In-Hg = inches of mercury pressure = can be a manometer or mercury filled gauge, used where pressures are low & extreme accuracy is desired = 1” Hg = .491 PSI
21
Compressor
Engine
Coupled Separables
22
1L 2L 3L 4L 5L
Left Bank
6
Terminology 术语
Capacity = (or flow rate) Volume of gas compressed and delivered at specified conditions of temperature & pressure measured at the compressor inlet. Usually expressed as volume/unit of time cubic feet per minute or cubic feet per day.
12
Terminology
Temperature Scales: Degrees Centigrade or Celsius (°C) = A scale used worldwide which relates to the metric system. At sea level, the freezing point of pure water is 0° & the boiling point is 100°. The distance between these two points is 100°.
15
Terminology
Temperature Scales: Degrees Rankin(cont.) One use for ° R: Finding Discharge Temperature (T2)
(K-1/K)
520°R T2 = T1 X Rc
T1 = 60° F + 460 =
Finding Approximate HP Requirement: To find the HP required for a two stage unit (example 2): Take the square root of the ratio found earlier: Rc = 17.71 = 4.20 HP = 21 x Rc x S x Q
Note: If we had not converted to psia the ratio would have been 30:1.
17
Terminology
Finding Approximate HP Requirement: To find the HP required for a single stage unit (example 1): Approximating HP Formula using Example #1 HP = 21 x Rc x S x Q Where:
SA 单作用 = Single Acting - The act of compressing on one end of the compressor cylinder. = Double Acting - The act of compressing on both ends of the compressor cylinder.
Rc = 600 psig + 14.7 = 614.7 psia = 2.863 200 psig + 14.7 = 214.7 psia
Example 2: Ps = 20 psig, Pd = 600 psig
Rc = 600psig + 14.7 = 614.7psia = 17.7 20psig + 14.7 = 34.7psia
Temperature range: Centigrade = 100° = Fahrenheit = 13 180° =
5 9
Terminology
Temperature Scales:
Converting from ° F to ° C expressed as follows: ° C = 5/9 X (° F - 32)
(1.26-1/1.26)
T2 = 520 X 2.94
.2
Ps = 500 PSIG Pd = 1500 PSIG K = 1.26
T2 = 520 X 2.94 T2 = 520 X 1.24 T2 = 644.8° R or 184.8° F
16
Terminology
Finding Ratio of Compression (RC) Example 1: Ps = 200 psig, Pd = 600 psig
8
Terminology
Total Swept Volume Example (DA):
6” Diameter x 11” Stroke 2.5” Piston Rod Diameter Total Swept Volume = (2 X 28.274 - 4.909) X 11 = (56.548 - 4.909) X 11 = 51.639 X 11 = 568.029 cu. In.
天然气压缩机 基础术语
压缩机基础术语
(Jargon)
压缩 = 压迫或压缩进入一个较小空间的动作。
2
压缩机基础术语
R/Rc Ps/P1 Pd/P2 Ts/T1 Td/T2 Ta Hp HE CE VE K = = = = = = = = = = = 压缩比 吸气压力 排气压力 吸气温度 排气温度 环境温度 马力（功率单位） 缸头端 曲柄端 容积效率 特定天然气的比热比
HP 21 Rc S Q = Horse Power = Standard (Constant) = Ratio Of Compression = # of Stages = Quantity in MMCFD
HP = 21 x 2.86 x 1 x 2 = 120.12 or 121
18
Terminology
Example:
Convert 100° F to ° C ° C = 5/9 X (100 - 32) = 5/9 X 68 = 37.8° C
14
Terminology
Temperature Scales: Degrees Rankin (° R) = Absolute temperatureEcientific work which relates the Fahrenheit scale to absolute temperature. Calculations are based on zero molecular energy. Zero Molecular Energy = -460° F or absolute zero Converting from ° F to ° R is expressed as follows: ° R = ° F + 460 Example: 100° F + 460 = 560° R