CN113944621B - Pipeline compressor energy consumption measurement method, system and computer storage medium - Google Patents

Abstract

The invention relates to a pipeline compressor energy consumption measuring method, a system and a computer storage medium, wherein the method comprises the following steps of dividing the whole variable compression process of a pipeline compressor into a plurality of variable compression subprocesses; sequentially solving the variable compression sub-work of each variable compression sub-process based on a variable power solving model; and superposing the variable compression sub-work of all the variable compression sub-processes to obtain the variable compression work of the whole variable compression process of the pipeline compressor. The invention divides the whole variable compression process into a plurality of sub-processes, and solves each sub-process respectively, so that the change of natural gas in the compression process can be better simulated, the application range of the direct integral model is wider, and the invention can be suitable for the compression process with phase change. In addition, the invention adopts a more accurate variable power solving model, namely a Malen model, to solve the variable compression sub-power of the variable compression sub-process, so that the variable compression power of the whole variable compression process can be calculated more accurately.

Description

Method, system and computer storage medium for measuring energy consumption of pipeline compressor

technical field

The invention relates to the field of energy management, in particular to a method, system and computer storage medium for measuring energy consumption of pipeline compressors.

Background technique

The pipeline compressor is a general-purpose machine used in the compressor station of the natural gas long-distance pipeline. The natural gas is compressed to a certain pressure in the pipeline compressor and then transported to the downstream users by the gas pipeline. The compression process of natural gas in the pipeline compressor is a variable compression process, and the power consumption corresponds to the variable compression work. The accuracy of polyvariable compression work calculation is very important for the optimal operation of pipeline compressors. The calculation formula usually adopted for the compression work W _pol in the existing variable compression process is:

The total energy consumption W _tot of the compressor can be calculated by the following formula:

In the formula, m is the variable process index, Z is the compressibility factor, R is the gas constant, T ₁ and p ₁ are the compressor inlet temperature and inlet pressure respectively, p ₂ is the compressor outlet pressure, η _pol is the pipeline compressor at Polytropic compression efficiency throughout the polytropic compression process.

The key factor affecting the calculation accuracy of the variable process compression work W _pol is the calculation of the variable process index. The calculation error of the variable process index can reach more than 4% in different process index selection methods. Therefore, it is necessary to study a calculation accuracy Higher variable process compression work measurement method.

Contents of the invention

The technical problem to be solved by the present invention is to provide a pipeline compressor energy consumption measurement method, system and computer storage medium, which can accurately calculate the compression work in the entire variable process of the pipeline compressor, and then can provide an optimal operation for the pipeline compressor Provide reliable evidence.

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a method for measuring energy consumption of pipeline compressors, comprising the following steps,

S1, according to the inlet and outlet pressures of the pipeline compressor, the entire variable compression process of the pipeline compressor is divided into multiple variable compression sub-processes;

S2, based on the multivariable work solution model, sequentially solve the multivariable compression sub-work of each multivariable compression sub-process;

S3, superimposing the polyvariable compression sub-works of all polyvariable compression sub-processes to obtain the polyvariable compression work of the entire polyvariable compression process of the pipeline compressor.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, the S2 is specifically,

S21, based on the polyvariable work solution model and the set condition M, and according to the known inlet condition K ₀ of the pipeline compressor, calculate the outlet condition K ₁ of the polyvariable compression sub-process G ₁ and the polyvariable compression sub-work W _{pol(1 )} ;

S22, using the exit condition K _x of the variable compression sub-process G _x as the entry condition F _x+1 of the variable compression sub-process G _x+1 ; in the variable compression sub-process G _x+1 , based on the multiple According to the variable power solution model and the set condition M, the outlet condition K _{x+1 and the multivariable compression subprocess G x+1} of the multivariable compression subprocess G _{x+1 are calculated according to the entry condition F x+ 1 of the multivariable compression subprocess G x +1} Variable compression sub-work W _pol(x+1) ; where x=1, 2, 3...n-1, n is the total number of variable compression sub-processes of the pipeline compressor.

Further, the known inlet condition K ₀ includes the inlet pressure P1 and the inlet temperature T1 of the pipeline compressor; wherein, the known inlet condition K ₀ is the inlet condition of the variable compression sub-process G ₁ ;

The set condition M includes a preset pressure ratio Alfa, a preset iteration termination criterion ε, and a preset temperature increment α;

The outlet condition K _x of the polyvariable compression sub-process G _x includes outlet pressure P _(x)j , outlet temperature T _(x)j , outlet specific enthalpy h _(x)j and outlet specific entropy s _(x)j ;

The inlet conditions F _x+1 of polyvariable compression sub-process G x+ ₁ include inlet pressure P _(x+1)i , inlet temperature T _(x+1)i , inlet specific enthalpy h _(x+1)i and inlet ratio Entropy s _(x+1)i ; and P _(x+1)i = P _(x)j , T _(x+1)i = T _(x)j , h _(x+1)i = h _{(x) j} , s _(x+1)i = s _(x)j ;

The calculation termination condition of said S2 is that the outlet pressure P _(n)j in the outlet condition _Kn of the polyvariable compression subprocess _Gn is greater than or equal to the known outlet condition of the pipeline compressor, wherein the known outlet condition of the pipeline compressor The condition is the outlet pressure P2 of the line compressor.

Further, the multivariable work solution model includes a Mallen model and a multivariable process compression work definition model;

其中，W_p′_ol(x)为多变压缩子过程G_x的多变压缩子功计算值，h_(x)i、s_(x)i和T_(x)i分别为多变压缩子过程G_x的入口比焓、入口比熵和入口温度，且h_(x)i＝h_(x-1)j，s_(x)i＝s_(x-1)j，T_(x)i＝T_(x-1)j；The Mallen model is specifically,

Among them, W _p ′ _ol(x) is the calculated value of the variable compression sub-work of the variable compression sub-process G _x , h _(x)i , s _(x)i and T _(x)i are the variable compression sub-process The inlet specific enthalpy, inlet specific entropy and inlet temperature of G _x , and h _(x)i = h _(x-1)j , s _(x)i = s _(x-1)j , T _(x)i = T _(x-1)j ;

The definition model of the multivariate process compression work is specifically, W _p ″ _ol(x) = η _pol (h _(x)j -h _(x)i ), wherein, W _p ″ _ol(x) is the multivariate compressor The defined value of the polyvariable compression subwork of the process G _x , η _pol is the polyvariable compression efficiency of the pipeline compressor in the entire polytropic compression process.

Further, let the inlet pressure P _(1)i =P1 of the multivariable compression subprocess _G1 , and let the inlet temperature of the multivariate compression subprocess _G1 be T _(1)i =T1;

The S21 is specifically,

S211, under the conditions of inlet pressure P _(1)i and inlet temperature T _(1)i , call the NIST database to calculate the inlet specific enthalpy h ( _{1 )i} and inlet specific entropy s _{(1 )i} ;

S212, according to the inlet pressure P _(1)i and the preset pressure ratio Alfa, through the formula P _(1)j = P _(1)i *Alfa, calculate the outlet pressure P ₍₁₎ of the variable compression sub-process G _{1 j} ;

S213, assuming that the outlet specific entropy s _(1)j of the variable compression sub-process G ₁ is equal to the inlet specific entropy s _(1)i , that is, s _(1)j = s _(1)i ; then at the outlet pressure P _{(1 )j} and the outlet specific entropy s _(1)j , call the NIST database to calculate the proposed outlet temperature T _s(1)j of the variable compression sub-process G ₁ ; and make the outlet temperature of the variable compression sub-process G ₁ T _(1)j = T _s(1)j ;

S214, under the conditions of the outlet temperature T _(1)j and the outlet pressure P _(1)j , call the NIST database to calculate the outlet specific enthalpy h _(1)j and the outlet specific entropy s ₍₁₎ of the variable compression subprocess G _{1 )j} ;

S215, according to the inlet specific enthalpy h _(1)i , inlet specific entropy s _(1)i and inlet temperature T _{(1)i in} S211, and the outlet specific enthalpy h _(1)j and outlet Specific entropy s _(1)j and outlet temperature T _(1)j , use the Mallen model to calculate the multivariate compression sub-work calculation value W′ _pol(1) of the multivariate compression sub-process G ₁ , and use the multivariate process compression Work definition model, calculate the variable compression sub-work definition value W″ _pol(1) of the variable compression sub-process _G1 ;

S216, judging whether the absolute value of the difference between the multivariable compression sub-work calculation value W′ _{pol (1)} of the multivariable compression sub-process G ₁ and the defined value W″ _{pol (1)} of the multivariable compression sub-work is less than or equal to the preset The iteration termination criterion ε, if not, add the outlet temperature T _(1)j to the preset temperature increment α, that is, T _(1)j = T _(1)j + α, and update the outlet temperature T _{(1) j} , and repeatedly execute the said S214～S215 in a loop until the difference between the multivariable compression sub-work calculation value W′ _pol(1) of the multivariable compression sub-process _G1 and the multivariable compression sub-work defined value W″ _pol(1) The absolute value of is less than or equal to the iteration termination criterion ε;

S217, when the absolute value of the difference between the multivariable compression sub-work calculation value W' _pol(1) and the multivariable compression sub-work definition value W" _pol(1) of the multivariable compression sub-process _G1 is less than or equal to the iteration termination When the criterion ε is used, the average value of the multivariable compression sub-work calculation value W′ _pol(1) and the multivariable compression sub-work definition value W″ _pol(1) of the multivariable compression sub-process G ₁ is used as the multivariable compression sub-process The variable compression subwork W _pol(1) of G ₁ .

Further, the final outlet temperature T _(1)j of the polyvariable compression sub-process G ₁ is the final updated outlet temperature T _(1)j in S216, and the final outlet specific enthalpy h _{(1) of} the polyvariable compression sub-process G 1 _j and the outlet specific entropy s _(1)j are, after the outlet temperature T _(1)j in the S214 is updated to the outlet temperature T _(1)j finally updated in the S216, the calculated outlet specific enthalpy h _(1)j and export ratio entropy s _(1)j .

Further, let the inlet pressure P _{(x+1)i of the polyvariable compression subprocess G x+1 =} P _(x)j , let the inlet temperature of the polyvariable compression subprocess G _x+1 be T _(x+1)i =T _(x)j ; Wherein, x=1,2,3...n-1, n is the total number of variable compression sub-processes of the pipeline compressor;

The S22 is specifically,

S221, under the conditions of the inlet pressure P _(x+1)i and the inlet temperature T _(x+1)i , call the NIST database to calculate the inlet specific enthalpy h _(x+1) of the variable compression sub-process G _{x+1 i} and the entrance ratio entropy s _(x+1)i ;

S222, according to the inlet pressure P _(x+1)i and the preset pressure ratio Alfa, through the formula P _(x+1)j =P _(x+1)i *Alfa, calculate the variable compression sub-process G _{x+ 1} outlet pressure P _(x+1)j ;

S223, assuming that the outlet specific entropy s _(x+1)j of the variable compression sub-process G _x+1 is equal to the inlet specific entropy s _(x+1)i , that is, s _(x+1)j = s _{(x+1 )i} ; then under the conditions of outlet pressure P _(x+1)j and outlet specific entropy s _(x+1)j , the NIST database is called to calculate the planned outlet temperature T s of the variable compression sub-process G _{x+1 ( x+1)j} ; And make the outlet temperature T _(x+1)j =T _s(x+1)j of the variable compression subprocess G _x+1 ;

S224, under the conditions of the outlet temperature T _(x+1)j and the outlet pressure P _(x+1)j , call the NIST database to calculate the outlet specific enthalpy h _{(x +1) of the variable compression sub-process G x+} 1 _j and export ratio entropy s _(x+1)j ;

S225, according to the inlet specific enthalpy h _(x+1)i , the inlet specific entropy s _(x+1)i , and the inlet temperature T _{(x+1)i in} S221 , and the outlet specific enthalpy h in S224 _(x+1)j , outlet specific entropy s _(x+1)j and outlet temperature T _(x+1)j , using the Mallen model to calculate the multivariate compression sub-work calculation of the multivariate compression subprocess G _x+1 Value W′ _pol(x+1) , and utilize the definition model of the multivariable process compression work to calculate the multivariate compression sub-work definition value W″ _pol(x+1) of the multivariate compression subprocess G _x+1 ;

S226, judge whether the absolute value of the difference between the multivariable compression sub-work calculation value W′ _{pol (x+1)} of the multivariable compression sub-process G _x+1 and the multivariable compression sub-work definition value W″ _{pol (x+1)} is less than or equal to the preset iteration termination criterion ε, if not, add the outlet temperature T _(x+1)j to the preset temperature increment α, that is, T _(x+1)j = T _{(x+1 )j} +α, update the outlet temperature T _(x+1)j , and execute the S224~S225 repeatedly until the multivariable compression sub-work calculation value W _{′ pol(x+ 1)} The absolute value of the difference with the variable compression subwork definition value W″ _pol(x+1) is less than or equal to the iteration termination criterion ε;

S227, when the absolute value of the difference between the multivariable compression sub-work calculation value W′ _{pol (x+1)} and the multivariable compression sub-work defined value W″ _{pol (x+1)} of the multivariable compression sub-process G _x+ 1 is less than Or when it is equal to the iteration termination criterion ε, the multivariable compression sub-work calculation value W′ _pol(x+1) of the multivariable compression sub-process G _x+1 and the multivariate compression sub-work definition value W″ _{pol(x +1)} as the polymorphic compression subwork W _pol(x+1) of the polymorphic compression subprocess G _x+1 .

Further, the final outlet temperature T _(x+1)j of the multivariable compression sub-process G _x+1 is the final updated outlet temperature T (x+1)j in S226, and the final outlet temperature T _(x+1)j of the multivariable compression sub-process G _x+1 The outlet specific enthalpy h _(x+1)j and outlet specific entropy s _(x+1)j are, the outlet temperature T _(x+1)j in the S224 is updated to the final updated outlet temperature in the S226 After T _(x+1)j , the calculated outlet specific enthalpy h _(x+1)j and outlet specific entropy s _(x+1)j .

Based on the above method for measuring energy consumption of a pipeline compressor, the present invention also provides a system for measuring energy consumption of a pipeline compressor.

A pipeline compressor energy consumption measurement system, including the following modules,

A polyvariable compression process decomposition module, which is used to divide the entire polyvariable compression process of the pipeline compressor into multiple polyvariable compression sub-processes according to the inlet and outlet pressures of the pipeline compressor;

A multivariable compression sub-work calculation module, which is used to sequentially solve the multivariable compression sub-work of each multivariable compression sub-process based on the multivariable work solution model;

The polyvariable compression sub-work superposition and summation module is used to superimpose the polyvariable compression sub-works of all the polyvariable compression sub-processes to obtain the polyvariable compression work of the entire polyvariable compression process of the pipeline compressor.

Based on the above method for measuring energy consumption of a pipeline compressor, the present invention further provides a computer storage medium.

A computer storage medium includes a memory, and a computer program stored on the memory, when the computer program is executed by a processor, the method for measuring energy consumption of a pipeline compressor as described above is implemented.

The beneficial effects of the present invention are: the present invention adopts the direct integral model to calculate the compression work of the polyvariable process, and the direct integral model divides the entire polyvariable compression process into several sub-processes, and solves each sub-process separately, so it can be better Therefore, the application range of the direct integral model is wider, and it can also be applied to the compression process with phase change. In addition, the present invention adopts a more accurate multivariable work solution model—Mallen model to solve the multivariable compression sub-work of the multivariate compression subprocess, from the first multivariate compression subprocess to the last multivariate compression subprocess , and then add the polyvariable compression sub-works of all polyvariable compression sub-processes to obtain the polyvariable compression work of the entire polyvariable compression process, so that the polyvariable compression work of the entire polyvariable compression process can be calculated more accurately; at the same time This calculation method avoids the calculation error caused by solving the multivariate process exponent m.

Description of drawings

Fig. 1 is the flowchart of a kind of pipeline compressor energy consumption measurement method of the present invention;

Fig. 2 is a schematic diagram of a method for measuring energy consumption of pipeline compressors according to the present invention;

Fig. 3 is a structural block diagram of a pipeline compressor energy consumption measurement system according to the present invention.

Detailed ways

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

As shown in Figure 1, a method for measuring energy consumption of a pipeline compressor includes the following steps,

S1, according to the inlet and outlet pressures of the pipeline compressor, the entire variable compression process of the pipeline compressor is divided into multiple variable compression sub-processes;

S2, based on the multivariable work solution model, sequentially solve the multivariable compression sub-work of each multivariable compression sub-process;

S3, superimposing the polyvariable compression sub-works of all polyvariable compression sub-processes to obtain the polyvariable compression work of the entire polyvariable compression process of the pipeline compressor.

In this specific example:

In the S1, the entire polyvariable compression process of the pipeline compressor can be equally divided into multiple polyvariable compression sub-processes.

Specifically, the S2 is specifically,

S21, based on the polyvariable work solution model and the set condition M, and according to the known inlet condition K ₀ of the pipeline compressor, calculate the outlet condition K ₁ of the polyvariable compression sub-process G ₁ and the polyvariable compression sub-work W _{pol(1 )} ;

S22, using the exit condition K _x of the variable compression sub-process G _x as the entry condition F _x+1 of the variable compression sub-process G _x+1 ; in the variable compression sub-process G _x+1 , based on the multiple According to the variable power solution model and the set condition M, the outlet condition K _{x+1 and the multivariable compression subprocess G x+1} of the multivariable compression subprocess G _{x+1 are calculated according to the entry condition F x+ 1 of the multivariable compression subprocess G x +1} Variable compression sub-work W _pol(x+1) ; where x=1, 2, 3...n-1, n is the total number of variable compression sub-processes of the pipeline compressor.

Further, the known inlet condition K ₀ includes inlet pressure P1 and inlet temperature T1 of the pipeline compressor; wherein, the known inlet condition K ₀ is the inlet condition of the polyvariable compression sub-process G ₁ ;

The set condition M includes a preset pressure ratio Alfa, a preset iteration termination criterion ε, and a preset temperature increment α;

The outlet condition K _x of the polyvariable compression sub-process G _x includes outlet pressure P _(x)j , outlet temperature T _(x)j , outlet specific enthalpy h _(x)j and outlet specific entropy s _(x)j ;

The inlet conditions F _x+1 of polyvariable compression sub-process G x+ ₁ include inlet pressure P _(x+1)i , inlet temperature T _(x+1)i , inlet specific enthalpy h _(x+1)i and inlet ratio Entropy s _(x+1)i ; and P _(x+1)i = P _(x)j , T _(x+1)i = T _(x)j , h _(x+1)i = h _{(x) j} , s _(x+1)i = s _(x)j ;

The calculation termination condition of said S2 is that the outlet pressure P _(n)j in the outlet condition _Kn of the polyvariable compression subprocess _Gn is greater than or equal to the known outlet condition of the pipeline compressor, wherein the known outlet condition of the pipeline compressor The condition is the outlet pressure P2 of the line compressor.

Further, the multivariable work solution model includes a Mallen model and a multivariable process compression work definition model;

其中，W′_pol(x)为多变压缩子过程G_x的多变压缩子功计算值，h_(x)i、s_(x)i和T_(x)i分别为多变压缩子过程G_x的入口比焓、入口比熵和入口温度，且h_(x)i＝h_(x-1)j，s_(x)i＝s_(x-1)j，T_(x)i＝T_(x-1)j；The Mallen model is specifically,

Among them, W′ _pol(x) is the calculated value of the variable compression sub-work of the variable compression sub-process G _x , h _(x)i , s _(x)i and T _(x)i are the variable compression sub-process G The inlet specific enthalpy, inlet specific entropy and inlet temperature _{of x} , and h _(x)i = h _(x-1)j , s _(x)i = s _(x-1)j , T _(x)i = T _{( x-1)j} ;

The definition model of the polyvariable process compression work is specifically, W″ _{pol (x)} = η _pol (h _(x)j -h _(x)i ), wherein, W″ _{pol (x)} is the polyvariable compression subprocess G The polyvariable compression sub-work definition value of _x , η _pol is the polyvariable compression efficiency of the pipeline compressor in the entire polyvariable compression process.

The physical parameters of natural gas can be obtained by calling the database of the National Institute of Standards and Technology (NIST). For example, under the condition of known P and T, v, s and h can be solved; under the condition of known P and s, v, h and T can be solved; under the condition of known P and h, the solution Output v, s, T; among them, P is the pressure, T is the temperature, v is the specific volume, s is the specific entropy, h is the specific enthalpy.

Specifically, let the inlet pressure P _(1)i = P1 of the polyvariable compression subprocess _G1 , and let the inlet temperature of the polyvariate compression subprocess _G1 be T _(1)i = T1;

The S21 is specifically,

S211, under the conditions of inlet pressure P _(1)i and inlet temperature T _(1)i , call the NIST database to calculate the inlet specific volume v ( _{1 )i} and inlet specific enthalpy h _{(1 )i} and entrance ratio entropy s _(1)i ;

S212, according to the inlet pressure P _(1)i and the preset pressure ratio Alfa, through the formula P _(1)j = P _(1)i *Alfa, calculate the outlet pressure P ₍₁₎ of the variable compression sub-process G _{1 j} ;

S213, assuming that the outlet specific entropy s _(1)j of the variable compression sub-process G ₁ is equal to the inlet specific entropy s _(1)i , that is, s _(1)j = s _(1)i ; then at the outlet pressure P _{(1 )j} and the outlet specific entropy s _(1)j , call the NIST database to calculate the proposed outlet temperature T _s(1)j of the variable compression sub-process G ₁ ; and make the outlet temperature of the variable compression sub-process G ₁ T _(1)j = T _s(1)j ;

S214. Under the conditions of outlet temperature T _(1)j and outlet pressure P _(1)j , call the NIST database to calculate outlet specific volume v ( _{1 )j} and outlet specific enthalpy h _{(1 )j} and export ratio entropy s _(1)j ;

S215, according to the inlet specific enthalpy h _(1)i , inlet specific entropy s _(1)i and inlet temperature T _{(1)i in} S211, and the outlet specific enthalpy h _(1)j and outlet Specific entropy s _(1)j and outlet temperature T _(1)j , use the Mallen model to calculate the multivariate compression sub-work calculation value W′ _pol(1) of the multivariate compression sub-process G ₁ , and use the multivariate process compression Work definition model, calculate the variable compression sub-work definition value W″ _pol(1) of the variable compression sub-process _G1 ;

S216, judging whether the absolute value of the difference between the multivariable compression sub-work calculation value W′ _{pol (1)} of the multivariable compression sub-process G ₁ and the defined value W″ _{pol (1)} of the multivariable compression sub-work is less than or equal to the preset The iteration termination criterion ε, if not, add the outlet temperature T _(1)j to the preset temperature increment α, that is, T _(1)j = T _(1)j + α, and update the outlet temperature T _{(1) j} , and repeatedly execute the said S214～S215 in a loop until the difference between the multivariable compression sub-work calculation value W′ _pol(1) of the multivariable compression sub-process _G1 and the multivariable compression sub-work defined value W″ _pol(1) The absolute value of is less than or equal to the iteration termination criterion ε;

S217, when the absolute value of the difference between the multivariable compression sub-work calculation value W' _pol(1) and the multivariable compression sub-work definition value W" _pol(1) of the multivariable compression sub-process _G1 is less than or equal to the iteration termination When the criterion ε is used, the average value of the multivariable compression sub-work calculation value W′ _pol(1) and the multivariable compression sub-work definition value W″ _pol(1) of the multivariable compression sub-process G ₁ is used as the multivariable compression sub-process The variable compression subwork W _pol(1) of G ₁ .

Furthermore, the final outlet temperature T _{(1)j of} the polyvariable compression sub-process G ₁ is the final updated outlet temperature T _(1)j in S216, and the final outlet specific enthalpy h _{(1 )j} and the outlet specific entropy s _(1)j are, after the outlet temperature T _(1)j in the S214 is updated to the outlet temperature T _(1)j finally updated in the S216, the calculated outlet ratio Enthalpy h _(1)j and outlet specific entropy s _(1)j .

Specifically, let the inlet pressure P _(x+1)i of the polyvariable compression subprocess G _x+ 1 =P _(x)j , let the inlet temperature of the polyvariable compression subprocess G _x+1 be T _{(x+1) i} =T _(x)j ; where, x=1,2,3...n-1, n is the total number of variable compression sub-processes of the pipeline compressor;

The S22 is specifically,

S221, under the conditions of the inlet pressure P _(x+1)i and the inlet temperature T _(x+1)i , call the NIST database to calculate the inlet specific volume v _{(x +1) of the variable compression sub-process G x+1 i} , entrance specific enthalpy h _(x+1)i and entrance specific entropy s _(x+1)i ;

S222, according to the inlet pressure P _(x+1)i and the preset pressure ratio Alfa, through the formula P _(x+1)j =P _(x+1)i *Alfa, calculate the variable compression sub-process G _{x+ 1} outlet pressure P _(x+1)j ;

S223, assuming that the outlet specific entropy s _(x+1)j of the variable compression sub-process G _x+1 is equal to the inlet specific entropy s _(x+1)i , that is, s _(x+1)j = s _{(x+1 )i} ; then under the conditions of outlet pressure P _(x+1)j and outlet specific entropy s _(x+1)j , the NIST database is called to calculate the planned outlet temperature T s of the variable compression sub-process G _{x+1 ( x+1)j} ; And make the outlet temperature T _(x+1)j =T _s(x+1)j of the variable compression subprocess G _x+1 ;

S224, under the conditions of the outlet temperature T _(x+1)j and the outlet pressure P _(x+1)j , call the NIST database to calculate the outlet specific volume v _(x+1) of the variable compression subprocess G _{x+1 j} , outlet specific enthalpy h _(x+1)j and outlet specific entropy s _(x+1)j ;

S225, according to the inlet specific enthalpy h _(x+1)i , the inlet specific entropy s _(x+1)i , and the inlet temperature T _{(x+1)i in} S221 , and the outlet specific enthalpy h in S224 _(x+1)j , outlet specific entropy s _(x+1)j and outlet temperature T _(x+1)j , using the Mallen model to calculate the multivariate compression sub-work calculation of the multivariate compression subprocess G _x+1 Value W′ _pol(x+1) , and utilize the definition model of the multivariable process compression work to calculate the multivariate compression sub-work definition value W″ _pol(x+1) of the multivariate compression subprocess G _x+1 ;

S226, judge whether the absolute value of the difference between the multivariable compression sub-work calculation value W′ _{pol (x+1)} of the multivariable compression sub-process G _x+1 and the multivariable compression sub-work definition value W″ _{pol (x+1)} is less than or equal to the preset iteration termination criterion ε, if not, add the outlet temperature T _(x+1)j to the preset temperature increment α, that is, T _(x+1)j = T _{(x+1 )j} +α, update the outlet temperature T _(x+1)j , and execute the S224~S225 repeatedly until the multivariable compression sub-work calculation value W _{′ pol(x+ 1)} The absolute value of the difference with the variable compression subwork definition value W″ _pol(x+1) is less than or equal to the iteration termination criterion ε;

S227, when the absolute value of the difference between the multivariable compression sub-work calculation value W′ _{pol (x+1)} and the multivariable compression sub-work defined value W″ _{pol (x+1)} of the multivariable compression sub-process G _x+ 1 is less than Or when it is equal to the iteration termination criterion ε, the multivariable compression sub-work calculation value W′ _pol(x+1) of the multivariable compression sub-process G _x+1 and the multivariate compression sub-work definition value W″ _{pol(x +1)} as the polymorphic compression subwork W _pol(x+1) of the polymorphic compression subprocess G _x+1 .

Furthermore, the final outlet temperature T _(x+1)j of the variable compression sub-process G x ₊₁ is the final updated outlet temperature T _(x+1)j in S226, and the variable compression sub-process G _x+1 The final outlet specific enthalpy h _(x+1)j and outlet specific entropy s _(x+1)j are, and the outlet temperature T _(x+1)j in the S224 is updated as the final updated outlet in the S226 After temperature T _(x+1)j , the calculated outlet specific enthalpy h _(x+1)j and outlet specific entropy s _(x+1)j .

In summary, the polyvariable compression work of the entire polyvariable compression process is:

In this specific embodiment, the above S21 and the above S22 are combined to obtain the comprehensive solution shown in FIG. 2 . as shown in picture 2:

Known conditions: inlet temperature T ₁ , inlet pressure p ₁ , outlet pressure p ₂ of the pipeline compressor, polytropic compression efficiency η _pol in the entire polytropic compression process.

Setting conditions: iteration termination criterion ε, small temperature increment α, and pressure ratio Alfa of the variable compression sub-process.

The comprehensive plan is as follows:

Firstly, the whole multivariate compression process is divided into several multivariate compression sub-processes. The inlet temperature T _i =T ₁ and the inlet pressure p _i =p ₁ of the first polyvariable compression sub-process. The calculation steps of the polyvariable compression sub-work W _poli of any polyvariable compression sub-process will be described below.

(1) Calculating the specific volume v _i , specific enthalpy h i and specific entropy _{s i} of natural gas under the conditions of inlet temperature T _i and inlet pressure p _i by calling NIST database;

(2) The variable compression sub-process outlet pressure p _j =p _i *Alfa, judge the size relationship between p _j and p ₂ , if p _j >p ₂ , set p _j =p ₂ ;

(3) The outlet pressure of the variable compression sub-process is p _j , assuming that the specific entropy of natural gas at the outlet of the variable compression sub-process is equal to that of the inlet, which is also s _i , call the NIST database to calculate the specific enthalpy h _sj of natural gas under this condition, and the temperature T _sj , and specific volume v _sj . Let the outlet temperature T _j =T _sj of the variable compression sub-process;

(4) The outlet temperature of the variable compression sub-process is T _j , the outlet pressure is p _j , and the specific volume v _j , specific enthalpy h _j and specific entropy s _j of natural gas are calculated by calling the NIST database under this condition;

(5) Step (1) obtains the import parameters, and step (4) obtains the export parameters, and respectively substitutes the calculation results into formula (4) for calculation to obtain the polyvariable work W _poli1 , which is substituted into formula (5) for calculation to obtain the polyvariable work W _poli2 ;

(6) Define the absolute value of the difference between W _poli1 and W _poli2 as abs(W _poli1 −W _poli2 ). If abs(W _poli1 -W _poli2 )>ε, add α to T _j , update the value of T _j , repeat steps (4), (5) until abs(W _poli1 -W _poli2 )≤ε;

(7) Set W _poli =(W _poli1 +W _poli2 )/2 to obtain the value of the variable work W _poli of the variable compression sub-process, and the calculation of the variable work W _poli of the variable compression sub-process is completed.

The exit condition of the last polyvariable compression sub-process is the entry condition of the next polyvariable compression sub-process, that is, after calculating the polyvariable work of a certain polyvariable compression sub-process, let p _i =p _j , T _i =T _j , that is to enter the calculation of the polyvariable work of the next polyvariable compression sub-process. The calculation termination condition of the entire polyvariable compression process is that the outlet pressure p _j ≥ p ₂ of a certain polyvariable compression sub-process. The polyvariable compression work of all polyvariable compression sub-processes is added to obtain the polyvariable compression work of the entire polyvariable compression process.

In this specific embodiment, the inlet and outlet parameters of a natural gas pipeline compressor are as follows: the inlet temperature is 307.55K, the inlet pressure is 6927kPa, the outlet temperature is 338.95K, the outlet pressure is 6927kPa, and the variable compression efficiency η _pol is 87.4 %. Using the method of the present invention and the method of the prior art (the calculation method of the formula (1) in the background art) to calculate the multivariate work of the natural gas pipeline compressor during the compression process, the results shown in Table 1 below are obtained. It can be seen from Table 1 that the calculation accuracy of the method of the present invention is greatly improved compared with the calculation accuracy of the traditional method.

Table 1: Calculation results of variable compression work of pipeline compressors by different methods

Based on the above method for measuring energy consumption of a pipeline compressor, the present invention also provides a system for measuring energy consumption of a pipeline compressor.

As shown in Figure 3, a pipeline compressor energy consumption measurement system includes the following modules,

A polyvariable compression process decomposition module, which is used to divide the entire polyvariable compression process of the pipeline compressor into multiple polyvariable compression sub-processes according to the inlet and outlet pressures of the pipeline compressor;

A multivariable compression sub-work calculation module, which is used to sequentially solve the multivariable compression sub-work of each multivariable compression sub-process based on the multivariable work solution model;

The polyvariable compression sub-work superposition and summation module is used to superimpose the polyvariable compression sub-works of all the polyvariable compression sub-processes to obtain the polyvariable compression work of the entire polyvariable compression process of the pipeline compressor.

Based on the above method for measuring energy consumption of a pipeline compressor, the present invention further provides a computer storage medium.

A computer storage medium includes a memory, and a computer program stored on the memory, when the computer program is executed by a processor, the method for measuring energy consumption of a pipeline compressor as described above is implemented.

The present invention uses the direct integral model to calculate the compression work of the variable process. The direct integral model divides the entire variable compression process into several sub-processes, and solves each sub-process separately, so it can better simulate the compression process of natural gas. Therefore, the application range of the direct integration model is wider, and it can also be applied to the compression process with phase change. In addition, the present invention adopts a more accurate multivariable work solution model—Mallen model to solve the multivariable compression sub-work of the multivariate compression subprocess, from the first multivariate compression subprocess to the last multivariate compression subprocess , and then add the polyvariable compression sub-works of all polyvariable compression sub-processes to obtain the polyvariable compression work of the entire polyvariable compression process, so that the polyvariable compression work of the entire polyvariable compression process can be calculated more accurately; at the same time This calculation method avoids the calculation error caused by solving the multivariate process exponent m.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (8)

1. A method for measuring energy consumption of a pipeline compressor, characterized by: comprises the steps of,

s1, dividing the whole variable compression process of a pipeline compressor into a plurality of variable compression sub-processes according to inlet and outlet pressures of the pipeline compressor;

s2, sequentially solving the variable compression sub-work of each variable compression sub-process based on a variable power solving model;

s3, superposing the variable compression sub-work of all the variable compression sub-processes to obtain variable compression work of the whole variable compression process of the pipeline compressor;

the step S2 is specifically that,

s21, based on the multiple transformation solving model and the set condition M, according to the known inlet condition K of the pipeline compressor ₀ Calculating a variable compression sub-process G ₁ Outlet condition K of (2) ₁ And variable compression sub-work W _pol(1) ；

S22, variable compression sub-process G _x Outlet condition K of (2) _x As a variable compression sub-process G _x+1 Inlet condition F of (2) _x+1 The method comprises the steps of carrying out a first treatment on the surface of the In the variable compression sub-process G _x+1 Based on the variable power solving model and the set condition M, according to the variable compression subprocess G _x+1 Inlet condition F of (2) _x+1 Calculating a variable compression sub-process G _x+1 Outlet condition K of (2) _x+1 And variable compression sub-work W _pol(x+1) The method comprises the steps of carrying out a first treatment on the surface of the Where x=1, 2,3. N-1, n is a pipeline total number of variable compression sub-processes of the compressor;

said known inlet condition K ₀ Including the inlet pressure P1 and inlet temperature T1 of the pipeline compressor; wherein the known inlet condition K ₀ Is a variable compression sub-process G ₁ Inlet conditions of (2);

the setting condition M comprises a preset pressure ratio Alfa, a preset iteration termination criterion epsilon and a preset temperature increment alpha;

variable compression sub-process G _x Outlet condition K of (2) _x Including the outlet pressure P _(x)j Outlet temperature T _(x)j Specific enthalpy of outlet h _(x)j And the outlet specific entropy s _(x)j ；

Variable compression sub-process G _x+1 Inlet condition F of (2) _x+1 Including the inlet pressure P _(x+1)i Inlet temperature T _(x+1)i Specific enthalpy of inlet h _(x+1)i And inlet specific entropy s _(x+1)i The method comprises the steps of carrying out a first treatment on the surface of the And P is _(x+1)i ＝P _(x)j ，T _(x+1)i ＝T _(x)j ，h _(x+1)i ＝h _(x)j ，s _(x+1)i ＝s _(x)j ；

The calculation termination condition of the S2 is a variable compression subprocess G _n Outlet condition K of (2) _n Outlet pressure P in (a) _(n)j Greater than or equal to the known outlet condition of the pipeline compressor, wherein the known outlet condition of the pipeline compressor is the outlet pressure P2 of the pipeline compressor.

2. The pipeline compressor energy consumption measurement method of claim 1, wherein: the variable power solving model comprises a Mallin model and a variable process compression power defining model;

the mullen model is specifically described as,

wherein W' _pol(x) Is a variable compression sub-process G _x Calculated value of variable compression sub-work, h _(x)i 、s _(x)i And T _(x)i Respectively the multiple compression subprocess G _x Inlet specific enthalpy, inlet specific entropy and inlet temperature, and h _(x)i ＝h _(x-1)j ，s _(x)i ＝s _(x-1)j ，T _(x)i ＝T _(x-1)j ；

The variable process compression work definition model is specifically W _pol(x) ＝η _pol (h _(x)j -h _(x)i ) Wherein W' _pol(x) Is a variable compression sub-process G _x Is defined by the variable compression sub-work values, eta _pol Is the variable compression efficiency of the pipeline compressor in the whole variable compression process.

3. The pipeline compressor energy consumption measurement method of claim 2, wherein: make the variable compression sub-process G ₁ Inlet pressure P of (2) _(1)i Let variable compression sub-process G =p1 ₁ Is at an inlet temperature T _(1)i ＝T1；

The step S21 is specifically that,

s211 at inlet pressure P _(1)i And inlet temperature T _(1)i Under the condition of calling NIST database, calculating variable compression subprocess G ₁ Is the inlet specific enthalpy h of (2) _(1)i And inlet specific entropy s _(1)i ；

S212, according to inlet pressure P _(1)i And a preset pressure ratio Alfa, by the formula P _(1)j ＝P _(1)i * Alfa, calculating to obtain a variable compression sub-process G ₁ Outlet pressure P of (2) _(1)j ；

S213, assume a polytropic compression sub-process G ₁ Is the outlet specific entropy s _(1)j Specific entropy s with inlet _(1)i Equal, i.e. let s _(1)j ＝s _(1)i The method comprises the steps of carrying out a first treatment on the surface of the At outlet pressure P _(1)j And the outlet specific entropy s _(1)j Under the condition of calling NIST database, calculating variable compression subprocess G ₁ Is set to the outlet temperature T _s(1)j The method comprises the steps of carrying out a first treatment on the surface of the And let the variable compression sub-process G ₁ Outlet temperature T of (2) _(1)j ＝T _s(1)j ；

S214, at outlet temperature T _(1)j And outlet pressure P _(1)j Under the condition of calling NIST database, calculating variable compression subprocess G ₁ Is the outlet specific enthalpy h of (2) _(1)j And the outlet specific entropy s _(1)j ；

S215, according to the inlet specific enthalpy h in S211 _(1)i Inlet specific entropy s _(1)i And inlet temperature T _(1)i And the outlet specific enthalpy h in the S214 _(1)j Specific entropy s of outlet _(1)j And outlet temperature T _(1)j Calculating a variable compression sub-process G by using a Mallin model ₁ Calculated value W 'of variable compression sub-work' _pol(1) And calculating a variable compression sub-process G by using a variable process compression work definition model ₁ Variable compressor work definition value W _pol(1) ；

S216, judging the variable compression sub-process G ₁ Calculated value W 'of variable compression sub-work' _pol(1) And a variable compression sub-work definition value W _pol(1) If the absolute value of the difference is smaller than or equal to the preset iteration termination criterion epsilon, if not, the outlet temperature T is calculated _(1)j Adding a pre-chargeA set temperature increment alpha, i.e. let T _(1)j ＝T _(1)j +α, update outlet temperature T _(1)j Repeating the steps S214-S215 until the variable compression sub-process G ₁ Calculated value W 'of variable compression sub-work' _pol(1) And a variable compression sub-work definition value W _pol(1) The absolute value of the difference is smaller than or equal to the iteration termination criterion epsilon;

s217, when the variable compression sub-process G ₁ Calculated value W 'of variable compression sub-work' _pol(1) And a variable compression sub-work definition value W _pol(1) When the absolute value of the difference is smaller than or equal to the iteration termination criterion epsilon, the variable compression subprocess G ₁ Calculated value W 'of variable compression sub-work' _pol(1) And a variable compression sub-work definition value W _pol(1) As the average value of the variable compression sub-process G ₁ Variable compression sub-work W _pol(1) 。

4. A pipeline compressor energy consumption measurement method according to claim 3, characterized in that: variable compression sub-process G ₁ Final outlet temperature T _(1)j For the final updated outlet temperature T in S216 _(1)j Variable compression sub-process G ₁ Final outlet specific enthalpy h _(1)j And the outlet specific entropy s _(1)j For, the outlet temperature T in the step S214 _(1)j Updated to the final updated outlet temperature T in S216 _(1)j Then, the calculated outlet specific enthalpy h _(1)j And the outlet specific entropy s _(1)j 。

5. A pipeline compressor energy measurement method according to claim 3 or 4, characterized in that: make the variable compression sub-process G _x+1 Inlet pressure P of (2) _(x+1)i ＝P _(x)j Make the variable compression sub-process G _x+1 Is at an inlet temperature T _(x+1)i ＝T _(x)j The method comprises the steps of carrying out a first treatment on the surface of the Wherein, x=1, 2, 3....n.. N. -1, n is pipeline compression the total number of variable compression sub-processes of the machine;

the step S22 is specifically that,

s221, at inlet pressure P _(x+1)i And inlet temperature T _(x+1)i Under the condition of calling NIST database, calculating variable compression subprocess G _x+1 Is the inlet specific enthalpy h of (2) _(x+1)i And inlet specific entropy s _(x+1)i ；

S222, according to inlet pressure P _(x+1)i And a preset pressure ratio Alfa, by the formula P _(x+1)j ＝P _(x+1)i * Alfa, calculating to obtain a variable compression sub-process G _x+1 Outlet pressure P of (2) _(x+1)j ；

S223, assume a polytropic compression sub-process G _x+1 Is the outlet specific entropy s _(x+1)j Specific entropy s with inlet _(x+1)i Equal, i.e. let s _(x+1)j ＝s _(x+1)i The method comprises the steps of carrying out a first treatment on the surface of the At outlet pressure P _(x+1)j And the outlet specific entropy s _(x+1)j Under the condition of calling NIST database, calculating variable compression subprocess G _x+1 Is set to the outlet temperature T _s(x+1)j The method comprises the steps of carrying out a first treatment on the surface of the And let the variable compression sub-process G _x+1 Outlet temperature T of (2) _(x+1)j ＝T _s(x+1)j ；

S224, at outlet temperature T _(x+1)j And outlet pressure P _(x+1)j Under the condition of calling NIST database, calculating variable compression subprocess G _x+1 Is the outlet specific enthalpy h of (2) _(x+1)j And the outlet specific entropy s _(x+1)j ；

S225, according to the inlet specific enthalpy h in S221 _(x+1)i Inlet specific entropy s _(x+1)i And inlet temperature T _(x+1)i And the outlet specific enthalpy h in the S224 _(x+1)j Specific entropy s of outlet _(x+1)j And outlet temperature T _(x+1)j Calculating a variable compression sub-process G by using a Mallin model _x+1 Calculated value W 'of variable compression sub-work' _pol(x+1) And calculating a variable compression sub-process G by using a variable process compression work definition model _x+1 Variable compressor work definition value W _pol(x+1) ；

S226, judging the variable compression sub-process G _x+1 Calculated value W 'of variable compression sub-work' _pol(x+1) And a variable compression sub-work definition value W _pol(x+1) If the absolute value of the difference is smaller than or equal to the preset iteration termination criterion epsilon, if not, the outlet temperature T is calculated _(x+1)j Adding a preset temperature increment alpha, namely, let T _(x+1)j ＝T _(x+1)j +α, update outlet temperature T _(x+1)j Repeating the steps S224-S225 until the variable compression sub-process G _x+1 Calculated value W 'of variable compression sub-work' _pol(x+1) And a variable compression sub-work definition value W _pol(x+1) The absolute value of the difference is smaller than or equal to the iteration termination criterion epsilon;

s227, when the variable compression sub-process G _x+1 Calculated value W 'of variable compression sub-work' _pol(x+1) And a variable compression sub-work definition value W _pol(x+1) When the absolute value of the difference is smaller than or equal to the iteration termination criterion epsilon, the variable compression subprocess G _x+1 Calculated value W 'of variable compression sub-work' _pol(x+1) And a variable compression sub-work definition value W _pol(x+1) As the average value of the variable compression sub-process G _x+1 Variable compression sub-work W _pol(x+1) 。

6. The pipeline compressor energy measurement method of claim 5, wherein: variable compression sub-process G _x+1 Final outlet temperature T _(x+1)j For the final updated outlet temperature T in said S226 _(x+1)j Variable compression sub-process G _x+1 Final outlet specific enthalpy h _(x+1)j And the outlet specific entropy s _(x+1)j For, the outlet temperature T in the S224 _(x+1)j Updated to the final updated outlet temperature T in S226 _(x+1)j Then, the calculated outlet specific enthalpy h _(x+1)j And the outlet specific entropy s _(x+1)j 。

7. A pipeline compressor energy measurement system, characterized by: comprising the following modules, wherein the modules are arranged in a row,

the variable compression process decomposition module is used for dividing the whole variable compression process of the pipeline compressor into a plurality of variable compression subprocesses according to the inlet pressure and the outlet pressure of the pipeline compressor;

the variable compression sub-work calculation module is used for sequentially solving the variable compression sub-work of each variable compression sub-process based on a variable power solving model;

the variable compression sub-work superposition summation module is used for superposing variable compression sub-work of all variable compression sub-processes to obtain variable compression work of the whole variable compression process of the pipeline compressor;

the variable compression sub-work calculation module is specifically used for,

based on the multiple transformation solving model and the set condition M, according to the known inlet condition K of the pipeline compressor ₀ Calculating a variable compression sub-process G ₁ Outlet condition K of (2) ₁ And variable compression sub-work W _pol(1) ；

Variable compression sub-process G _x Outlet condition K of (2) _x As a variable compression sub-process G _x+1 Inlet condition F of (2) _x+1 The method comprises the steps of carrying out a first treatment on the surface of the In the variable compression sub-process G _x+1 Based on the variable power solving model and the set condition M, according to the variable compression subprocess G _x+1 Inlet condition F of (2) _x+1 Calculating a variable compression sub-process G _x+1 Outlet condition K of (2) _x+1 And variable compression sub-work W _pol(x+1) The method comprises the steps of carrying out a first treatment on the surface of the Where x=1, 2,3. N-1, n is a pipeline total number of variable compression sub-processes of the compressor;

said known inlet condition K ₀ Including the inlet pressure P1 and inlet temperature T1 of the pipeline compressor; wherein the known inlet condition K ₀ Is a variable compression sub-process G ₁ Inlet conditions of (2);

the setting condition M comprises a preset pressure ratio Alfa, a preset iteration termination criterion epsilon and a preset temperature increment alpha;

variable compression sub-process G _x Outlet condition K of (2) _x Including the outlet pressure P _(x)j Outlet temperature T _(x)j Specific enthalpy of outlet h _(x)j And the outlet specific entropy s _(x)j ；

Variable compression sub-process G _x+1 Inlet condition F of (2) _x+1 Including the inlet pressure P _(x+1)i Inlet temperature T _(x+1)i Specific enthalpy of inlet h _(x+1)i And inlet specific entropy s _(x+1)i The method comprises the steps of carrying out a first treatment on the surface of the And P is _(x+1)i ＝P _(x)j ，T _(x+1)i ＝T _(x)j ，h _(x+1)i ＝h _(x)j ，s _(x+1)i ＝s _(x)j ；

The computation termination condition of the variable compression sub-work computation module is a variable compression sub-process G _n Outlet condition K of (2) _n Outlet pressure P in (a) _(n)j Greater than or equal to the known outlet condition of the pipeline compressor, wherein the known outlet condition of the pipeline compressor is the outlet pressure P2 of the pipeline compressor.

8. A computer storage medium, characterized by: comprising a memory, and a computer program stored on the memory, which when executed by a processor implements the pipeline compressor energy measurement method of any one of claims 1 to 6.

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