This standard specifies the terms, symbols and their definitions or explanations for positive displacement compressors. This standard applies to all types of positive displacement compressors. GB/T 4975-1995 General Terms for Positive Displacement Compressors GB/T4975-1995 Standard download decompression password: www.bzxz.net

130 621. 512 : 001. 4
National Standard of the People's Republic of China
GB/T4975-1995
Displacement compressors vocabulary-General
Issued on June 12, 1995
Implemented on October 1, 1995
Issued by State Technical Supervision Bureau
National Standard of the People's Republic of China
Displacement compressors vocabulary—General GB/I4975-1995
Substituted for GB4975-85
This standard is equivalent to the part related to displacement compressors in the international standard IS03857-1577 Compressors, pneumatic tools and pneumatic machines.
1 Subject content and scope of application
This standard specifies the terms, symbols and their definitions or explanations for displacer compressors. This standard is applicable to various positive displacement compressors (hereinafter referred to as displacement compressors): 2 General
2.1 Displacer sweeping capacity
the swept volume for a displacer compressor is the volume swept by the first stage compression element of a compressor per unit time. 2.2 Displacer flow rate
the swept volume for a displacer compressor is the volume swept by the first stage compression element of a compressor per unit time. 2.3 Clearance volume The volume of the compression chamber occupied by the scavenging gas at the end of the compression cycle. 2.4 Relative clearance volume The ratio of the clearance volume of a stage to the scavenging volume of the compression element of that stage. 2.5 Standard inlet point (standard suction point) The suction point considered as representative on the compressor. This position varies with the structure and installation method of the compressor (refer to the relevant compressor test method standards).
2.6 Standard discharge point
cn standard discharge point (standeri discharge point)fz join national reference approval by the National Technical Supervision Bureau on 1995-06-12 and implementation on 1995-10-01
GB/T4975—1995
The representative discharge point on a compressor, which varies with the structure and installation method of the compressor (refer to relevant standard medical standards).
2.7 Standard suction state
eu standard suction control (standard suction control) fr canditions narmalesd'aspiration state of the suction device in the standard position of the compressor. 2.B Standard discharge state
ea star.card discharge controlr candit:ons normales de refouiemcntThe state of the exhaust gas at the exhaust position of the compressor. 2.9 Compressibility factor
fr facteur de corupressibli-e represents the absolute difference between the actual gas state and the ideal gas state. It can be expressed as the following formula:
Where: 2-compressibility factor
pressure;
V.-volume ratio
R-gas band number
T-thermodynamic temperature (absolute temperature)
3 temperature
3. 1 static temperature
en static temperature
fr temperature
tt||The fluid temperature measured without being affected by the fluid velocity. 3.2 cynarmic temperature
fr terperature 3.3 Total temperature
en total temperature
i: temperaturc totelc
the sum of static strength and dynamic temperature. It indicates the state of the fluid after the kinetic energy of the fluid is converted into heat energy without loss. When the fluid is at rest, the temperature and total temperature are equal.
3.4 ​​Critical temperature
rn critical temperuture
fr tenphrature criuqur
extreme temperature that is independent of pressure. Above this temperature, the discontinuity between the stagnant phase and the gas phase is measured. 3.5 Comparative temperature
rn reduers temperature
fr temperature reduite
GB/T 4975--1995
The ratio of the thermodynamic temperature of a fluid to its critical thermodynamic temperature 3.6 Suction temperature(suetion termpcrture)Tr tepfralure daspirutiuta
The total temperature of the gas at the standard suction position of the compression blade. 3.7 Exhaust temperature The full temperature of the air compressor at its standard exhaust position. 4.1 Atmospheric pressure The absolute positive pressure of the atmosphere measured at the designated location. 4.2 Gauge pressure The pressure obtained with the atmospheric pressure as zero point. 4.3 Absolute pressure The pressure obtained with the absolute pressure as zero point. It is the algebraic sum of atmospheric pressure and gauge pressure (static pressure or total pressure). 4.4 Static pressure The pressure obtained without being affected by the velocity of the fluid. 4.5 Dynamic pressure The pressure obtained with the atmospheric pressure as zero point. dyuanaigu
When the kinetic energy of the gas flowing at a high speed is completely and without loss, that is, converted into pressure energy, the increased pressure is expressed as the following formula:
In the formula: dynamic pressure;
Degree:
G flow rate.
4.6 Total pressure
er.total pressure
fr preson tntele
GA/T4975—1995
The sum of static pressure and dynamic pressure. It expresses the pressure after the kinetic energy of the system is losslessly converted into pressure energy. In the static state, the static pressure and total pressure are equal 4. 7 Critical pressure
cn eritize! prcssure
fr siun itigue
The limit pressure that is independent of temperature. At this pressure, no discontinuity between the liquid phase and the gas phase is observed. 4.8 Ratio
-n reduced pressure
Ir Ftexsinn -lui1e
The ratio of the absolute pressure of a fluid to its critical absolute pressure. 4.9 Inlet pressure (pressure) pressure of the aspirator The average absolute pressure of the aspirator at the standard discharge position. 4.10 Discharge pressure The average absolute pressure of the aspirator at the standard discharge position. Note: When the gas pressure is low enough, the static pressure can be substituted for the normal pressure. The exhaust pressure at the beginning of the discharge of the foil machine is shown in the figure. Note that the pressure ratio should be the same as the total pressure. 4.11 Overall ratio The total pressure ratio is the pressure ratio of the maximum and minimum pressures. 4.12 Proportional pressure ratio The pressure ratio of any stage in a multistage compressor. The exhaust pressure is the value before the intercooler. 4.13 Overall pressure ratio The pressure ratio of the longest stage in a compressor. The exhaust pressure is the value after the intercooler (including the secondary compressor). 4.14 Ideal multistage compressor mulri-nagecomprassiprIr urripresion poly etagee ilpaleThe equalization correction of the gas in the plate when the suction density and power consumption of each stage are equal. 5 Flow
5.7 Actual volume rate of compressor
en actual volume rate nd lw of g compressor (actual capacity)fr debit-volume reel d'un compresseur (debit reel')The actual volumetric flow rate at the standard exhaust position when the gas is compressed and discharged by the compressor should be converted to the full density, total pressure and composition (such as the state of density>) at the standard suction position. 52 Standard volume rate of compressor
GB/T4975—1995
cn standard volume rate of flow (atandard capacity)fr debit-volume normul
The actual flow rate of the gas compressed and discharged by the wax press at the approved exhaust position. This flow rate should be converted to the standard operating conditions (temperature and pressure).
6 Power
According to the selected reference process: the power cycle can provide: a.
Isothermal process, that is, the compression process is isothermal and has no losses b. Isotropic (reversible adiabatic) process, that is, the process in which the filling is constant during the normal process, and the reversible compression process, that is, the process in which the compression is carried out reversibly along a series of curves that are as close to the actual standard as possible. 6.1 Theoretical power
cn theoreticul required gain puissance absorbee theoriqueIn a compressor without losses, according to the selected reference process, the power required to reduce the gas from a given suction pressure to a given exhaust pressure in theory. 6.2 Indicated power
en indicated power
ir pressure indicator
The power corresponding to the pressure-volume diagram recorded by the indicator, 6.3 Internal power
the indicated power plus the power lost due to heat transfer and leakage. 6.4 Equivalent power
the power required by the compressor drive shaft, which is equal to the internal power plus the mechanical losses, but does not include the power lost by external transmission such as gears or belts.
7 Specific energy
7.1 Theoretical specific energy requirementfr energie rnenritur de cnmpreraianThe work required to compress unit mass of gas or unit volume of gas according to the selected standard process <isothermal, isothermal, variable> is called theoretical air volume specific energy or theoretical volume total energy, respectively. 7.2 Actual specific energy
en actual specific energy iejuiremen!fr encrgic volume absorbee reeleThe work required to compress unit mass of gas by unit volume of gas, the work required by the main shaft of the compressor, is called actual mass specific energy or actual volume specific energy, respectively.
B Male efficiency
B1 Theoretical efficiency
cn carefulelemental eficiency
fr reridrmner:1 theoriguc
GB/T4975-1995
The ratio of diagnostic power to indicated power. Depending on the selected reversible benchmark error, the theoretical efficiency can include variable efficiency, equal extraction efficiency and equal source efficiency.
B.2 Internal efficiency
en internal afficierwy
fr rendemat internal
the ratio of theoretical power to internal power
8.3 Mechanical efficiency
en mechanical efficiency
fr renderment mecanique
the ratio of internal efficiency to shaft power.
8.4 Overall efficiency
en overall elficiency
fr rendement global
the ratio of theoretical power to shaft power,
8.5 Volumetric efficiency
en volumetric efficiency
fr rendernent valuation
the ratio of the actual volumetric flow of the compressor to the ideal volumetric flow of the compressor: variable consideration of the influence of cooling. 9 Specified performance
erspecified performance
fr performance specified in the contract.
position: manufacturers will show and describe their compressors in the nominal performance.10. The Chinese version is introduced in Appendix A (Supplementary Document), the English version is introduced in Appendix (Supplementary Document), and the French version is introduced in Appendix C (Supplementary Document). 11 Special numbers and unitswwW.bzxz.Net
Commonly used symbols and units are shown in Appendix D (examination documents), G
Standard exhaust price
Standard exhaust state
Standard air supply volume
Standard air intake state
Table power
Air pressure
Dynamic temperature
Bore pressure
Comparative temperature
Comparative pressure
Specified performance
Machine efficiency
Total pressure ratio of the level
No pressure ratio
Static temperature
For the theoretical performance:
Theoretical power
Theoretical efficiency
Ideal transfer level
Critical temperature change
Critical pressure
Internal power||tt| |GB/14975—1995
Appendix A
Chinese Introduction
(Filling Part)
Internal Efficiency
Exhaust Overflow
Exhaust Pressure
Total Temperature
Total Pressure
1.1Total Pressure Ratio
Variable Effect
Actual Specific Energy
Suction Temperature
Suction Pressure
Relative Residual Volume
Normal Compressor Standard Volumetric Flow
Compressor Air Flow
Compressor Scavenging Volume
Actual Volumetric Flow of Compressor
Compressibility Coefficient
Residual Volume
Indicated Power
Shaft Power
Total Efficiency
elisol: te pre-xu
actusl apec.fic energy tequireanen!GE/F4975-1995
Appendix B
English index
(cup filler)
aiu.l voluant ralr of flom of e cunpressatmospheri: pressure
clearaace vo.ue
compaessiuility Eactar
criuical pressure
Iritical tcrr.pereture
dine barge jiresnnr
discharge reperaicre
disglatnin-ml fis: a linleement cumpressudynamic pressure
dynumic temperutu::
gaugupressure
ideal mu.ti-stage compressinnEguinitel pwer
inlel pressuretsuction presfure)inlet tempcrature(guecion lemperture)nrernsl e[.c.en?y
:nternal power
mcchanical eiiiclency
cversll efficiency
avcrali stagepressureratio
reduced pressure | conditipn)standard inlet point (standard suctian point)sandord ulumr rate of fla(sianderd capacity?-aciss
statie lrinpHtalure
swepl vojure lor a lisplucement tunprtsxoyT
thearetica: efliciency
thenretica! reguired powe!
theoretical epecific energy requirementtotal pressure
lotal pre3sure ratio-
volunteirir efficiency
Appendix C
French index
(external parts)
caracteriaiquessptcititee
compressor poly-etagee idealcconditions normnles d'aspirationcandicions nornales de refoulernentP
debit engerdre d'un compresweur volumer:jnue:debi:-volume norma!
dehit-salume reel d' un compresseur (drhin reel)...3.5
energle theo-ique de compressinnenurgic volume absotbee reeliecseacemnr!
espare mors relatif
tarteur de campressililite
pir1 nnrnl l'angiraon
point rprual de refaulamen!
μression abnl:se
p+iut tlinsperigu
Fression crininpur
pression d'aspirztian
[ircssion de refeuulemem
preaeion r:ysmicjue
GE/T49751995
Press:on ettective(pressinn mannm:ripur?prassior reduste
pressjun s:atiquc
ptessist: inlals
puissance Jarbre
puisssnrc absorbee theoriye
puissam:p Snliyuer
puissanre intene
Tapport de pressian Far piagrrappor:g.obuldeprersicr.par wcag.r:[urt toa] decompression
rendamrut glubal
Iendemeat in:er:e
rendemen mezinigue
Tamleinent thcoriguc
:endement voluriftriga
temperarurr ritiyurs
+4r44-4
temperature d'aspiralion
temperaturedereloulsment
lemperuturedyamique
Irmperututerahile
temperaturetatique
temperature torale
GB/T4975
volume enrendre(cylindree)d'un campresseur Appendix D
Symbols and units
(Rhombus examination)
Symbols and units used are shown in Table 2 and Table 3 of [1, Table D1
Mass specific volume
Barrier
Enzhou Tong degree
Angular return room
Mass density
Celsius
Thermal primary school degree
Original most specific volume
Product ratio
New disk statistics
Capacitance resistance
·Shangjia
Change overhang index
Symbols and units
ML\\T-!
n'/ruol
Pure teaching)
Other real month units
t +g rrug
J/Lwb/u
/ht/un,Lu.l
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