CN112459984B - Performance test calculation method for isothermal compressor - Google Patents

Abstract

The invention provides a performance test calculation method for an isothermal compressor, which comprises the following steps: step one, collecting parameters of an isothermal compressor: step two, calculating process multivariable preliminary determination: step 201, acquiring pressure and temperature parameters of inlet and outlet of each stage in a design state; step 202, calculating multiple variables at each level of the design state: step 203, preliminarily determining the multivariable of each stage of the test state: making the test state multi-variable at each level equal to the design state multi-variable at each level; step three, preliminary calculation of test data: step four, data comparison and correlation coefficient selection iterative computation: comparing the complete machine power N obtained by calculation in the step three with the actually measured power N, calculating a relevant power adjustment coefficient, and recalculating multiple variables at each stage: and (3) redetermining the multiple variables of each stage of the test state: making the multi-variables of each stage in the test state equal to the multi-variables of each stage obtained by recalculation; repeatedly iterating the calculation of the third step and the calculation of the fourth step; and step five, calculating the related characteristic parameters.

Description

Performance test calculation method for isothermal compressor

Technical Field

The invention belongs to the field of compressors, relates to an isothermal compressor, and particularly relates to a performance test calculation method for the isothermal compressor.

Background

Isothermal compressors with built-in coolers are widely used in the industrial fields of air separation and the like. The built-in cooler enables the high-temperature gas after each stage of compression to be cooled immediately in time and then enter the next stage for compression again. The overall energy consumption of the unit is lower than that of other types of compressor units with the same scale, and the overall occupied area is also smaller than that of other types of compressor units with the same scale. However, the application of the built-in cooler, especially the use of a special gas distributor for gas distribution in order to ensure that the high-temperature gas can be sufficiently cooled, increases the nonuniformity of the high-temperature gas flow at the outlet of the previous stage and the low-temperature gas flow at the inlet of the subsequent stage of the built-in cooler, especially the nonuniformity of the temperature field, and brings certain difficulties to the performance test and evaluation of the unit. Especially, quantitative and accurate evaluation of performance test and analysis of all levels is difficult to achieve.

At present, in the test analysis of the isothermal centrifugal compressor, test points are arranged at an inlet and an outlet of each stage of the compressor according to the JB/T3165 standard to obtain pressure and temperature parameters of the inlet and the outlet of each stage of the compressor, a flow meter arranged on a test pipeline obtains flow measurement parameters of the flow meter, and the measurement parameters are calculated and analyzed by combining related environmental medium parameters and unit operation characteristic parameters through the principle of a thermal balance method to obtain the overall thermal performance of the compressor and the thermal performance of each stage.

Due to the structural limitation of the isothermal compressor, the temperature testing precision of the inlet and the outlet of each stage is difficult to guarantee. The inlet and the outlet of the compressor complete machine are connected with the test pipeline, pressure and temperature measuring points can be arranged according to the test standard requirements strictly, and related pressure and temperature parameters can be obtained accurately. The compressor flow measurement is arranged on the relevant test pipeline, and the flow parameters can be accurately obtained. The difficulty in measuring the pressure and temperature parameters between compressor stages (namely the relevant parameters of the inlet and the outlet of the built-in cooler) is high. In contrast, the pressure field is relatively stable, and accurate pressure measurement parameters can be obtained by increasing the number of measuring points for averaging or seeking a stable flow area for arranging the measuring points. For the inter-stage temperature measurement, the applicant also tries to obtain temperature parameters by increasing the number of measuring points for averaging and seeking for arranging measuring points in a stable flow region in the previous research process, and carries out analysis and calculation according to the calculation method recommended by JB/T3165. The obtained result often has great deviation from the design concept and the theoretical principle, and sometimes even has the conclusion of violating the thermodynamic principle. The test of the isothermal compressor is caused, and the applicant can only give qualitative analysis conclusion in the early research process, and hardly gives quantitative conclusion.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a performance test calculation method for an isothermal compressor, which aims at the test difficulty brought by the characteristics of the isothermal compressor structure and solves the technical problem that the accurate quantitative test result is difficult to give out by aiming at the characteristics of the isothermal compressor structure in the prior art.

In order to solve the technical problems, the invention adopts the following technical scheme:

a performance test calculation method for an isothermal compressor, wherein the isothermal compressor is provided with a built-in cooler, comprises the following steps:

step one, collecting parameters of an isothermal compressor:

the parameters comprise:

environmental parameters: including atmospheric pressure and atmospheric temperature;

flow parameters: including mass flow rate;

and (3) inlet parameters of each stage: including stage inlet pressures and stage inlet temperatures;

exit parameters at each level: including stage outlet pressures;

parameters of each stage of cooler: the method comprises the steps of feeding water mass flow of each stage of cooler, feeding water temperature of each stage of cooler and discharging water temperature of each stage of cooler;

compressor related parameters: including compressor speed and compressor power;

preparing parameters at the early stage: including adiabatic index, gas constant and cooling water specific heat;

step two, preliminary determination of multiple variables in the calculation process:

step 201, checking design parameters corresponding to the test working condition points of the isothermal compressor, and acquiring the inlet and outlet pressure and temperature parameters of each stage in a design state, namely:

including at least a design secondary inlet pressure P_2j', design second level inlet temperature T_2j', design second level outlet pressure P_2C' and design State Secondary Outlet temperature T_2C’；

Step 202, calculating multiple variables at each level of the design state:

at least including a design state two-level multivariable

Step 203, preliminarily determining the multivariable of each stage of the test state:

making the test state multi-variable at each level equal to the design state multi-variable at each level;

step three, preliminary calculation of test data:

at least two stages of power calculation are included:

in the formula:

k is the adiabatic index;

r is a gas constant;

Q_mis the mass flow rate;

T_2jcalculating for the second stage inlet temperature:

P_2jis the second inlet pressure;

P_2Ca secondary outlet pressure;

σ₂is a test state secondary multivariable;

step four, data comparison and correlation coefficient selection iterative computation:

the total machine power N obtained by the calculation of the step three_MeterComparing with the measured power N, calculating a relevant power adjustment coefficient, and recalculating multiple variables at each stage:

power adjustment coefficient:

at least two-stage multivariate recalculation:

in the formula:

T_{2j meter 2}Is a two-stage inlet temperatureRecalculating the result;

T_{2C meter 2}Recalculating the results for the secondary outlet temperature;

and (3) redetermining the multiple variables of each stage of the test state:

making the multi-variables of each stage in the test state equal to the multi-variables of each stage obtained by recalculation;

substituting the calculated inlet and outlet temperature parameter values of each stage into the corresponding calculation formula of the third step for recalculation, and repeatedly iterating the calculation of the third step and the calculation of the fourth step until the complete machine power N obtained by calculation_MeterIs equal to the measured power N;

calculating related characteristic parameters;

the related characteristic parameters comprise inlet volume flow of each stage, pressure ratio of each stage, efficiency of each stage and power of each stage.

The invention also has the following technical characteristics:

the isothermal compressor is a four-stage isothermal compressor, three built-in coolers are arranged in the compressor, the four-stage isothermal compressor is divided into a first-stage cooler, a second-stage cooler, a third-stage cooler and a fourth-stage cooler, and the three built-in coolers are divided into a first-stage cooler, a second-stage cooler and a third-stage cooler; the method is characterized by comprising the following steps:

step one, collecting parameters of an isothermal compressor:

the parameters comprise:

environmental parameters: including atmospheric pressure Pa and atmospheric temperature Ta;

flow parameters: including mass flow rate Q_m；

Primary inlet parameters: including a primary inlet pressure P_1jAnd primary inlet temperature T_1j；

Primary outlet parameters: including a primary outlet pressure P_1C；

Primary cooler parameters: comprises a primary cooler water inlet mass flow q_{1m water}First-stage cooler inlet water temperature T_{1j Water}And the outlet water temperature T of the primary cooler_{1C water}；

Secondary import parameters: comprises thatSecondary inlet pressure P_2j；

Secondary outlet parameters: including a secondary outlet pressure P_2C；

Secondary cooler parameters: comprises a secondary cooler water inlet mass flow q_{2m water}Water inlet temperature T of secondary cooler_{2j water}And the outlet water temperature T of the secondary cooler_{2C water}；

Three-level import parameters: including three inlet pressures P_3j；

And (3) three-level outlet parameters: three stage outlet pressure P_3C；

Parameters of the tertiary cooler: water inlet mass flow q of three-stage cooler_{3m water}Water inlet temperature T of three coolers_{3j Water}And the outlet water temperature T of the three-stage cooler_{3C water}；

Four-stage inlet parameters: including four stages of inlet pressure P_4j；

Four-stage outlet parameters: four stage outlet pressure P_4CAnd a fourth stage outlet temperature T_4C；

Compressor related parameters: the compressor speed N and the compressor power N;

preparing parameters at the early stage: adiabatic index k, gas constant R and specific heat of cooling water C_{p water}；

Step two, calculating process multivariable preliminary determination:

step 201, checking design parameters corresponding to the test working condition points of the isothermal compressor, and acquiring the inlet and outlet pressure and temperature parameters of each stage in a design state, namely:

design primary inlet pressure P_1j', design first-level inlet temperature T_1j', design first stage outlet pressure P_1C' and design State first order Outlet temperature T_1C’；

Design second order inlet pressure P_2j', design second level inlet temperature T_2j', design second level outlet pressure P_2C' and design State Secondary Outlet temperature T_2C’；

Design state three-stage inlet pressure P_3j' design state three-level inlet temperature T_3j', design three-stage outlet pressure P_3C' and design three stage exit temperature T_3C’；

Design state four stage inlet pressure P_4j', design four-stage inlet temperature T_4j', design four stage outlet pressure P_4C' and design State four stage Outlet temperature T_4C’；

Step 202, calculating multiple variables at each level of the design state:

first-level multivariable of design state

Design state two-level multivariable

Three-level multivariable of design state

Design state four-stage multivariable

Step 203, preliminarily determining the multivariable of each stage of the test state:

order:

first-order multivariable sigma of test state₁＝σ₁'；

Test state two-stage multivariable sigma₂＝σ'₂；

Three-stage multivariable sigma of test state₃＝σ'₃；

Test state four-stage multivariable sigma₄＝σ'₄；

Step three, preliminary calculation of test data:

primary outlet temperature calculation:

calculating the secondary inlet temperature:

Q₁＝C_{p water}q_1m(T_{1c Water}-T_{1j Water})；

Calculating the secondary outlet temperature:

calculating the three-stage inlet temperature:

Q₂＝C_{p water}q_2m(T_{2c water}-T_{2j water})；

Calculating the temperature of the three stages of outlets:

four-stage inlet temperature calculation:

Q₃＝C_{p water}q_3m(T_{3c water}-T_{3j Water})；

Four-stage outlet temperature calculation:

primary power calculation:

calculating secondary power:

calculating three-stage power:

four-stage power calculation:

and (3) calculating the power of the whole machine: n is a radical of_Meter＝N_{1 meter}+N_{2 meter}+N_{3 meter}+N_{4 meter}；

In the formula:

Q₁the heat of a first-stage built-in cooler;

Q₂the heat of a secondary built-in cooler;

Q₃the heat of a three-stage built-in cooler is adopted;

step four, data comparison and correlation coefficient selection iterative computation:

the total machine power N obtained by the calculation of the step three_MeterComparing the four-level outlet temperature T with the actually measured power N, and calculating the four-level outlet temperature T obtained in the step three_{4C meter}And actually measuring the four-stage outlet temperature T_4CComparing, calculating the related power adjustment coefficient, and recalculating the multi-variables at each stage:

power adjustment coefficient:

recalculating a primary multivariant:

and (3) recalculating a secondary multivariant:

and (3) recalculating the three-level multivariant:

four-stage multivariable recalculation:

in the formula:

T_{1C meter 2}Recalculating the results for the primary outlet temperature;

T_{2j meter 2}Recalculating the results for the secondary inlet temperature;

T_{2C meter 2}Recalculating the results for the secondary outlet temperature;

T_{3j meter 2}Recalculating results for the third level inlet temperature;

T_{3C meter 2}Recalculating results for the tertiary outlet temperatures;

T_{4j meter 2}Recalculating the results for the four stage inlet temperature;

T_{4C meter 2}Recalculating the results for the four stage outlet temperature;

λ₁the value range of the coefficient is 0.95-1.05;

λ₂the value range of the coefficient is 0.95-1.05;

λ₃the value range of the coefficient is 0.95-1.05;

λ₄the value range of the coefficient is 0.95-1.05;

and (3) redetermining the multiple variables of each stage of the test state:

order:

first-order multivariable sigma of test state₁＝σ_{1 meter}；

Test state two-stage multivariable sigma₂＝σ_{2 meter}；

Three-stage multivariable sigma of test state₃＝σ_{3 meter}；

Test state four-stage multivariable sigma₄＝σ_{4 meter}；

And calculating the inlet and outlet temperature parameter values T of each level_{1C meter 2}、T_{2j meter 2}、T_{2C meter 2}、T_{3j meter 2}、T_{3C meter 2}And T_{4j meter 2}Substituting into the corresponding calculation formula in the third step for recalculation, and repeating the iteration of the calculation in the third step and the calculation in the fourth step until the complete machine power N obtained by calculation_MeterEqual to the measured power N and calculating the obtained four-stage outlet temperature T_{4C meter}And actually measuring the four-stage outlet temperature T_4C；

Step five, calculating related characteristic parameters:

primary inlet volume flow:

primary pressure ratio:

primary efficiency:

primary power:

volume flow of a secondary inlet: q_2V＝Q_m/ρ₂×60；

Secondary pressure ratio:

secondary efficiency:

secondary power:

tertiary inlet volume flow: q_3V＝Q_m/ρ₃×60；

Third-stage pressure ratio:

tertiary efficiency:

three-stage power:

four-stage inlet volume flow: q_4V＝Q_m/ρ₄×60；

Fourth-stage pressure ratio:

four-stage efficiency:

four-stage power:

in the formula:

ρ₁is the first level inlet density;

ρ₂the second level inlet density;

ρ₃the density is three-level inlet density;

ρ₄is a four-stage inlet density.

Compared with the prior art, the invention has the following technical effects:

the test calculation method disclosed by the invention has the advantages that (I) the obtained superposition calculation result is compared and analyzed with the tested model level complete machine result, the parameters are basically consistent, the data deviation is within the range allowed by the calculation error, the result accuracy is high, and the quantitative test of the isothermal compressor is realized.

(II) the test calculation method can be applied to the test and field test analysis and evaluation of the isothermal compressor with the built-in cooler and the analysis and treatment of the auxiliary relevant operation problems.

(III) the test calculation method of the invention obtains the complete machine thermodynamic performance of the isothermal compressor and the thermodynamic performance parameters of all stages by combining the thermodynamic correlation principle and the compressor characteristics through experimental tests, substituting the calculation parameters for the relevant temperature parameters with high measurement difficulty through theoretical reasoning and iterative calculation.

The present invention will be explained in further detail with reference to examples.

Detailed Description

It is to be understood that all devices and components of the present invention, unless otherwise specified, are intended to be within the scope of the present invention, as defined in the appended claims.

It should be noted that the types, units and acquisition modes of the parameters collected by the isothermal compressor in the present invention are as follows:

environmental parameters:

pa- -atmospheric pressure in kPa (measured value);

ta- -atmospheric temperature in K (measured);

flow parameters:

Q_m-mass flow in kg/s (measured value);

primary inlet parameters:

P_1j-primary inlet pressure in Pa (taking inlet test pressure transmitter average);

T_1j-primary inlet temperature in K (taking inlet test temperature transmitter average);

primary outlet parameters:

P_1C-primary outlet pressure in Pa (take-off test pressure transmitter mean);

primary cooler parameters:

q_{1m water}-primary cooler inlet water mass flow in kg/s (measured value);

T_{1j Water}-primary cooler inlet water temperature in K (measured value);

T_{1C water}-primary cooler exit water temperature in K (measured value);

secondary import parameters:

P_2j-secondary inlet pressure in Pa (taking inlet test pressure transmitter mean);

secondary outlet parameters:

P_2C-secondary outlet pressure in Pa (take-off test pressure transmitter mean);

secondary cooler parameters:

q_{2m water}-mass flow of the secondary cooler inlet water in kg/s (measured);

T_{2j water}-secondary cooler inlet water temperature in K (measured value);

T_{2C water}-secondary cooler effluent temperature in K (measured value);

three-level import parameters:

P_3j-tertiary inlet pressure in Pa (taking inlet test pressure transmitter average);

and (3) three-level outlet parameters:

P_3C-a tertiary outlet pressure in Pa (take-off test pressure transmitter mean);

parameters of the tertiary cooler:

q_{3m water}-mass flow of water entering the tertiary cooler in kg/s (measured);

T_{3j Water}-the tri-cooler inlet water temperature in K (measured value);

T_{3C water}-the outlet water temperature of the tertiary cooler in K (measured value);

four-stage inlet parameters: in the relevant characteristic parameter

P_4j-four levels of inlet pressure in Pa (taking inlet test pressure transducer mean);

four-stage outlet parameters:

P_4C-a quaternary outlet pressure in Pa (take-off test pressure transmitter mean);

T_4C-four levels of outlet temperature in K (take-off test temperature transmitter mean);

compressor related parameters:

n-compressor speed in r/min (measured);

n- -compressor power in kW (measured);

preparing parameters at the early stage:

k — adiabatic index, unit 1, (air k 1.4);

r-gas constant, in J/(kg · K) (air R288.3);

Cp_{water (W)}Specific heat of cooling water, in J/(kg. DEG C.) (selected).

In the isothermal compressor-related characteristic parameters according to the present invention, the units of the parameters are as follows:

primary inlet volume flow Q_1vVolume flow Q of secondary inlet_2vThree-stage inlet volume flow Q_3vAnd four stages of inlet volume flow Q_4vAll units of (are m)³/min；

Primary power N₁Second order power N₂Three-stage power N₃And four levels of power N₄The units of (A) are all kW.

The present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention fall within the protection scope of the present invention.

Example 1:

according to the technical scheme, the performance test calculation method of the isothermal compressor is provided in the embodiment, the compressor is a four-stage isothermal compressor, three built-in coolers are arranged in the compressor, the four-stage isothermal compressor is divided into a first-stage cooler, a second-stage cooler, a third-stage cooler and a fourth-stage cooler, and the three built-in coolers are divided into a first-stage cooler, a second-stage cooler and a third-stage cooler; the method comprises the following steps:

step one, collecting parameters of an isothermal compressor:

the parameters comprise:

environmental parameters: including atmospheric pressure Pa and atmospheric temperature Ta;

flow parameters: including mass flow rate Q_m；

Primary inlet parameters: including a primary inlet pressure P_1jAnd primary inlet temperature T_1j；

Primary outlet parameters: including a primary outlet pressure P_1C；

Primary cooler parameters: comprises a primary cooler water inlet mass flow q_{1m water}First-stage cooler inlet water temperature T_{1j Water}And the outlet water temperature T of the primary cooler_{1C water}；

Secondary import parameters: including a secondary inlet pressure P_2j；

Secondary outlet parameters: including a secondary outlet pressure P_2C；

Secondary cooler parameters: comprises a secondary cooler water inlet mass flow q_{2m water}And the water inlet temperature T of the secondary cooler_{2j water}And the outlet water temperature T of the secondary cooler_{2C water}；

Three-level import parameters: including three inlet pressures P_3j；

And (3) three-level outlet parameters: three stage outlet pressure P_3C；

Parameters of the tertiary cooler: water inlet mass flow q of three-stage cooler_{3m water}Water inlet temperature T of three coolers_{3j Water}And the outlet water temperature T of the three-stage cooler_{3C water}；

Four-stage inlet parameters: including four stages of inlet pressure P_4j；

Four-stage outlet parameters: four-stage outlet pressure P_4CAnd a fourth stage outlet temperature T_4C；

Compressor related parameters: the compressor speed N and the compressor power N;

preparing parameters at the early stage: adiabatic index k, gas constant R and specific heat of cooling water C_{p water}；

Step two, calculating process multivariable preliminary determination:

step 201, checking design parameters corresponding to the test working condition points of the isothermal compressor, and acquiring the inlet and outlet pressure and temperature parameters of each stage in a design state, namely:

design primary inlet pressure P_1j', design first-level inlet temperature T_1j', design first stage outlet pressure P_1C' and design State first order Outlet temperature T_1C’；

Design second stage inlet pressure P_2j', design second level inlet temperature T_2j', design second level outlet pressure P_2C' and design State Secondary Outlet temperature T_2C’；

Design state three-stage inlet pressure P_3j' design state three-level inlet temperature T_3j', design three-stage outlet pressure P_3C' and design three stage exit temperature T_3C’；

Design state four stage inlet pressure P_4j', design four-stage inlet temperature T_4j', design four stage outlet pressure P_4C' and design State four stage Outlet temperature T_4C’；

Step 202, calculating multiple variables at each level of the design state:

first-level multivariable of design state

Design state two-level multivariable

Three-level multivariable design state

Design state four-stage multivariable

Step 203, preliminarily determining the multivariable of each stage of the test state:

order:

first-order multivariable sigma of test state₁＝σ₁'；

Test state two-stage multivariable sigma₂＝σ'₂；

Three-stage multivariable sigma of test state₃＝σ'₃；

Test state four-stage multivariable sigma₄＝σ'₄；

Step three, preliminary calculation of test data:

primary outlet temperature calculation:

calculating the secondary inlet temperature:

Q₁＝C_{p water}q_1m(T_{1c Water}-T_{1j Water})；

Calculating the secondary outlet temperature:

calculating the three-stage inlet temperature:

Q₂＝C_{p water}q_2m(T_{2c water}-T_{2j water})；

Calculating the temperature of the three stages of outlets:

four-stage inlet temperature calculation:

Q₃＝C_{p water}q_3m(T_{3c water}-T_{3j Water})；

Four-stage outlet temperature calculation:

primary power calculation:

calculating secondary power:

calculating three-stage power:

four-stage power calculation:

and (3) calculating the power of the whole machine: n is a radical of_Meter＝N_{1 meter}+N_{2 meter}+N_{3 meter}+N_{4 meter}；

In the formula:

Q₁the heat of a first-stage built-in cooler;

Q₂the heat of a secondary built-in cooler;

Q₃the heat of a three-stage built-in cooler is adopted;

step four, data comparison and correlation coefficient selection iterative computation:

the total machine power N obtained by the calculation of the step three_MeterComparing the four-level outlet temperature T with the actually measured power N, and calculating the four-level outlet temperature T obtained in the step three_{4C meter}And actually measuring the four-stage outlet temperature T_4CComparing, calculating the related power adjustment coefficient, and recalculating the multi-variables at each stage:

power adjustment coefficient:

recalculating a primary multivariant:

and (3) recalculating a secondary multivariant:

and (3) recalculating the three-level multivariant:

four-stage multivariable recalculation:

in the formula:

T_{1C meter 2}Recalculating the results for the primary outlet temperature;

T_{2j meter 2}Recalculating the results for the secondary inlet temperature;

T_{2C meter 2}Recalculating the results for the secondary outlet temperature;

T_{3j meter 2}Recalculating results for the third level inlet temperature;

T_{3C meter 2}Recalculating results for the tertiary outlet temperatures;

T_{4j meter 2}Recalculating the results for the four stage inlet temperature;

T_{4C meter 2}Recalculating the results for the four stage outlet temperature;

λ₁the value range of the coefficient is 0.95-1.05;

λ₂the value range of the coefficient is 0.95-1.05;

λ₃the value range of the coefficient is 0.95-1.05;

λ₄the value range of the coefficient is 0.95-1.05;

and (3) redetermining the multiple variables of each stage of the test state:

order:

first-order multivariable sigma of test state₁＝σ_{1 meter}；

Test state two-stage multivariable sigma₂＝σ_{2 meter}；

Three-stage multivariable sigma of test state₃＝σ_{3 meter}；

Test state four-stage multivariable sigma₄＝σ_{4 meter}；

And calculating the inlet and outlet temperature parameter values T of each level_{1C meter 2}、T_{2j meter 2}、T_{2C meter 2}、T_{3j meter 2}、T_{3C meter 2}And T_{4j meter 2}Substituting into the corresponding calculation formula in the third step for recalculation, and repeating the iteration of the calculation in the third step and the calculation in the fourth step until the complete machine power N obtained by calculation_MeterIs equal to the actually measured power N and calculates the obtained four-stage outlet temperature T_{4C meter}And actually measuring the four-stage outlet temperature T_4C；

Step five, calculating related characteristic parameters:

primary inlet volume flow: q_1V＝Q_m/ρ₁×60；

Primary pressure ratio:

primary efficiency:

primary power:

volume flow of a secondary inlet: q_2V＝Q_m/ρ₂×60；

Secondary pressure ratio:

secondary efficiency:

secondary power:

tertiary inlet volume flow: q_3V＝Q_m/ρ₃×60；

Third-stage pressure ratio:

three-stageEfficiency:

three-stage power:

four-stage inlet volume flow: q_4V＝Q_m/ρ₄×60；

Fourth-stage pressure ratio:

four-stage efficiency:

four-stage power:

in the formula:

ρ₁is the first level inlet density;

ρ₂the second level inlet density;

ρ₃the density is three-level inlet density;

ρ₄is a four-stage inlet density.

Application example:

the isothermal compressor in the application example is an isothermal centrifugal compressor unit which operates on site, the compressor is a four-stage isothermal compressor, three built-in coolers are arranged in the compressor, the four-stage isothermal compressor is divided into a first-stage cooler, a second-stage cooler, a third-stage cooler and a fourth-stage cooler, and the three built-in coolers are divided into a first-stage cooler, a second-stage cooler and a third-stage cooler. The design parameters are shown in table 1.

TABLE 1 design parameters for isothermal compressors

The application example adopts the performance test calculation method of the isothermal compressor in the embodiment 1 to calculate.

In this application example, the parameters of the isothermal compressor collected according to the method of step one of example 1 are shown in table 2.

TABLE 2 parameters collected

In this application example, the relevant characteristic parameters obtained by the method of step five in example 1 are shown in table 3.

TABLE 3 relevant characteristic parameters

The performance test calculation method of the isothermal compressor, provided by the invention, has the advantages that the superposed calculation result is compared and analyzed with the tested model level complete machine result, the parameters are basically consistent, the data deviation is very small, and the very small deviation is caused by calculation errors.

Claims (2)

1. A performance test calculation method for an isothermal compressor, wherein the isothermal compressor is provided with a built-in cooler, is characterized by comprising the following steps:

step one, collecting parameters of an isothermal compressor:

the parameters comprise:

environmental parameters: including atmospheric pressure and atmospheric temperature;

flow parameters: including mass flow rate;

and (3) inlet parameters of each stage: including stage inlet pressures and stage inlet temperatures;

exit parameters at each level: including stage outlet pressures;

parameters of each stage of cooler: the method comprises the steps of feeding water mass flow of each stage of cooler, feeding water temperature of each stage of cooler and discharging water temperature of each stage of cooler;

compressor related parameters: including compressor speed and compressor power;

preparing parameters at the early stage: including adiabatic index, gas constant and cooling water specific heat;

step two, calculating process multivariable preliminary determination:

step 201, checking design parameters corresponding to the test working condition points of the isothermal compressor, and acquiring the inlet and outlet pressure and temperature parameters of each stage in a design state, namely:

including at least a design secondary inlet pressure P_2j', design second level inlet temperature T_2j', design second level outlet pressure P_2C' and design State Secondary Outlet temperature T_2C’；

Step 202, calculating multiple variables at each level of the design state:

at least including a design state two-level multivariable

Step 203, preliminarily determining the multivariable of each stage of the test state:

making the test state multi-variable at each level equal to the design state multi-variable at each level;

step three, preliminary calculation of test data:

at least two stages of power calculation are included:

in the formula:

k is the adiabatic index;

r is a gas constant;

Q_mis the mass flow rate;

T_2jcalculating for the second stage inlet temperature:

P_2jis the second inlet pressure;

P_2Ca secondary outlet pressure;

σ₂is a test state secondary multivariable;

step four, data comparison and correlation coefficient selection iterative computation:

the total machine power N obtained by the calculation of the step three_MeterComparing with the measured power N, calculating a relevant power adjustment coefficient, and recalculating multiple variables at each stage:

power adjustment coefficient:

at least two-stage multivariate recalculation:

in the formula:

T_{2j meter 2}Recalculating the results for the secondary inlet temperature;

T_{2C meter 2}Recalculating the results for the secondary outlet temperature;

and (3) redetermining the multiple variables of each stage of the test state:

making the multi-variables of each stage in the test state equal to the multi-variables of each stage obtained by recalculation;

substituting the calculated inlet and outlet temperature parameter values of each stage into the corresponding calculation formula of the third step for recalculation, and repeatedly iterating the calculation of the third step and the calculation of the fourth step until the complete machine power N obtained by calculation_MeterIs equal to the measured power N;

calculating related characteristic parameters;

the related characteristic parameters comprise inlet volume flow of each stage, pressure ratio of each stage, efficiency of each stage and power of each stage.

2. The isothermal compressor performance test calculation method according to claim 1, wherein the isothermal compressor is a four-stage isothermal compressor, three internal coolers are arranged in the compressor, the four-stage isothermal compressor is divided into a first-stage cooler, a second-stage cooler, a third-stage cooler and a fourth-stage cooler, and the three internal coolers are divided into a first-stage cooler, a second-stage cooler and a third-stage cooler; the method is characterized by comprising the following steps:

step one, collecting parameters of an isothermal compressor:

the parameters comprise:

environmental parameters: including atmospheric pressure Pa and atmospheric temperature Ta;

flow parameters: including mass flow rate Q_m；

Primary inlet parameters: including a primary inlet pressure P_1jAnd primary inlet temperature T_1j；

Primary outlet parameters: including a primary outlet pressure P_1C；

Primary cooler parameters: comprises a primary cooler water inlet mass flow q_{1m water}First-stage cooler water inlet temperature T_{1j Water}And the outlet water temperature T of the primary cooler_{1C water}；

Secondary import parameters: including a secondary inlet pressure P_2j；

Secondary outlet parameters: including a secondary outlet pressure P_2C；

Secondary cooler parameters: comprises a secondary cooler water inlet mass flow q_{2m water}Water inlet temperature T of secondary cooler_{2j water}And the outlet water temperature T of the secondary cooler_{2C water}；

Three-level import parameters: including three inlet pressures P_3j；

And (3) three-level outlet parameters: three stage outlet pressure P_3C；

Parameters of the tertiary cooler: water inlet mass flow q of three-stage cooler_{3m water}Cooling by threeTemperature T of inlet water of device_{3j Water}And the outlet water temperature T of the three-stage cooler_{3C water}；

Four-stage inlet parameters: involving four levels of inlet pressure P_4j；

Four-stage outlet parameters: four-stage outlet pressure P_4CAnd a fourth stage outlet temperature T_4C；

Compressor related parameters: the compressor speed N and the compressor power N;

preparing parameters at the early stage: adiabatic index k, gas constant R and specific heat of cooling water C_{p water}；

Step two, calculating process multivariable preliminary determination:

step 201, checking design parameters corresponding to the test working condition points of the isothermal compressor, and acquiring the inlet and outlet pressure and temperature parameters of each stage in a design state, namely:

design primary inlet pressure P_1j', design first-level inlet temperature T_1j', design first stage outlet pressure P_1C' and design State first order Outlet temperature T_1C’；

Design second stage inlet pressure P_2j', design second level inlet temperature T_2j', design second level outlet pressure P_2C' and design State Secondary Outlet temperature T_2C’；

Design state three-stage inlet pressure P_3j' design state three-level inlet temperature T_3j', design three-stage outlet pressure P_3C' and design three stage exit temperature T_3C’；

Design state four stage inlet pressure P_4j', design four-stage inlet temperature T_4j', design four stage outlet pressure P_4C' and design State four stage Outlet temperature T_4C’；

Step 202, calculating multiple variables at each level of the design state:

first-level multivariable of design state

Design state two-level multivariable

Three-level multivariable of design state

Design state four-stage multivariable

Step 203, preliminarily determining the multivariable of each stage of the test state:

order:

first-order multivariable sigma of test state₁＝σ’₁；

Test state two-stage multivariable sigma₂＝σ'₂；

Three-stage multivariable sigma of test state₃＝σ'₃；

Test state four-stage multivariable sigma₄＝σ'₄；

Step three, preliminary calculation of test data:

primary outlet temperature calculation:

calculating the secondary inlet temperature:

Q₁＝C_{p water}q_1m(T_{1c Water}-T_{1j water})；

Calculating the secondary outlet temperature:

calculating the three-stage inlet temperature:

Q₂＝C_{p water}q_2m(T_{2c water}-T_{2j water})；

Calculating the temperature of the three stages of outlets:

four-stage inlet temperature calculation:

Q₃＝C_{p water}q_3m(T_{3c water}-T_{3j Water})；

Four-stage outlet temperature calculation:

primary power calculation:

calculating secondary power:

calculating three-stage power:

four-stage power calculation:

and (3) calculating the power of the whole machine: n is a radical of_Meter＝N_{1 meter}+N_{2 meter}+N_{3 meter}+N_{4 meter}；

In the formula:

Q₁the heat of a first-stage built-in cooler;

Q₂the heat of a secondary built-in cooler;

Q₃the heat of a three-stage built-in cooler is adopted;

step four, data comparison and correlation coefficient selection iterative computation:

the total machine power N obtained by the calculation of the step three_MeterComparing the four-level outlet temperature T with the actually measured power N, and calculating the four-level outlet temperature T obtained in the step three_{4C meter}And actually measuring the four-stage outlet temperature T_4CComparing, calculating the related power adjustment coefficient, and recalculating the multi-variables at each stage:

power adjustment coefficient:

recalculating a primary multivariant:

and (3) recalculating a secondary multivariant:

and (3) recalculating the three-level multivariant:

four-stage multivariable recalculation:

in the formula:

T_{1C meter 2}Recalculating the results for the primary outlet temperature;

T_{2j meter 2}Recalculating the results for the secondary inlet temperature;

T_{2C meter 2}Recalculating the results for the secondary outlet temperature;

T_{3j meter 2}Recalculating results for the third level inlet temperature;

T_{3C meter 2}Recalculating results for the tertiary outlet temperatures;

T_{4j meter 2}Recalculating the results for the four stage inlet temperature;

T_{4C meter 2}Recalculating the results for the four stage outlet temperature;

λ₁the value range of the coefficient is 0.95-1.05;

λ₂the value range of the coefficient is 0.95-1.05;

λ₃the value range of the coefficient is 0.95-1.05;

λ₄the value range of the coefficient is 0.95-1.05;

and (3) redetermining the multiple variables of each stage of the test state:

order:

first-order multivariable sigma of test state₁＝σ_{1 meter}；

Test state two-stage multivariable sigma₂＝σ_{2 meter}；

Three-stage multivariable sigma of test state₃＝σ_{3 meter}；

Test state four-stage multivariable sigma₄＝σ_{4 meter}；

And calculating the inlet and outlet temperature parameter values T of each level_{1C meter 2}、T_{2j meter 2}、T_{2C meter 2}、T_{3j meter 2}、T_{3C meter 2}And T_{4j meter 2}Substituting into the corresponding calculation formula in the third step for recalculation, and reversing the calculations in the third step and the fourth stepRepeating the iteration till the obtained overall power N is calculated_MeterIs equal to the actually measured power N and calculates the obtained four-stage outlet temperature T_{4C meter}And actually measuring the four-stage outlet temperature T_4C；

Step five, calculating related characteristic parameters:

primary inlet volume flow:

primary pressure ratio:

primary efficiency:

primary power:

volume flow of a secondary inlet:

secondary pressure ratio:

secondary efficiency:

secondary power:

tertiary inlet volume flow:

third-stage pressure ratio:

tertiary efficiency:

three-stage power:

four-stage inlet volume flow:

fourth-stage pressure ratio:

four-stage efficiency:

four-stage power:

in the formula:

ρ₁is the first level inlet density;

ρ₂the second level inlet density;

ρ₃the density is three-level inlet density;

ρ₄is a four-stage inlet density.