CN109740242B - Unified energy flow calculation method of electricity-gas comprehensive energy system considering natural gas thermal process - Google Patents

Unified energy flow calculation method of electricity-gas comprehensive energy system considering natural gas thermal process Download PDF

Info

Publication number
CN109740242B
CN109740242B CN201811633610.XA CN201811633610A CN109740242B CN 109740242 B CN109740242 B CN 109740242B CN 201811633610 A CN201811633610 A CN 201811633610A CN 109740242 B CN109740242 B CN 109740242B
Authority
CN
China
Prior art keywords
natural gas
gas
model
node
flow
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811633610.XA
Other languages
Chinese (zh)
Other versions
CN109740242A (en
Inventor
余娟
包诗媛
杨知方
代伟
郭林
马梦楠
覃明星
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chongqing University
Original Assignee
Chongqing University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Chongqing University filed Critical Chongqing University
Priority to CN201811633610.XA priority Critical patent/CN109740242B/en
Publication of CN109740242A publication Critical patent/CN109740242A/en
Application granted granted Critical
Publication of CN109740242B publication Critical patent/CN109740242B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Management, Administration, Business Operations System, And Electronic Commerce (AREA)

Abstract

The invention discloses a unified energy flow calculation method of an electricity-gas comprehensive energy system considering a natural gas thermal process, which mainly comprises the following steps: 1) and establishing an equipment model considering the thermodynamic process of the natural gas system. The plant model includes a natural gas pipeline model and a compressor model. 2) And establishing a unified energy flow solving model of the electricity-gas integrated energy system based on the equipment model. The unified energy flow solving model of the electricity-gas comprehensive energy system comprises a natural gas system model, an electric power system model and a coupling element model. 3) And calculating the energy flow of the to-be-detected electricity-gas comprehensive energy system by using the unified energy flow solving model of the electricity-gas comprehensive energy system. The invention can more accurately reflect the temperature change condition of the natural gas caused by the thermodynamic process and the influence of the temperature change condition on other state variables in the system.

Description

Unified energy flow calculation method of electricity-gas comprehensive energy system considering natural gas thermal process
Technical Field
The invention relates to the field of electricity-gas comprehensive energy systems, in particular to a unified energy flow calculation method of an electricity-gas comprehensive energy system considering a natural gas thermal process.
Background
In recent years, with the increasing installed capacity of a gas turbine, the coupling between an electric power system and a natural gas system is increasingly tight, so that the unified power flow solving of the electricity-gas integrated energy system is very important. The thermodynamic process of natural gas through different elements will result in constant changes in air temperature, and the changes in air temperature, air pressure, flow rate, etc. are mutually affected and coupled. The natural gas temperature can have a significant effect on both the power system and the natural gas system, for example, affecting the energy consumption of the compressor and the energy conversion efficiency of the gas turbine. The gas temperature and the gas pressure can also influence the generation of hydrate together, and the hydrate can cause the reduction of gas transmission efficiency, the excessive accumulation of local gas pressure, the damage of gas network equipment, even cause the interruption of gas transmission and the reduction of the gas supply reliability for users. When an interruption occurs in the gas turbine supply branch, power supply reliability may also be affected. Therefore, besides the gas pressure, the gas temperature must also be taken into account as a state variable.
Most of the existing unified energy flow calculation models of the electricity-gas integrated energy system only consider the flow balance of nodes, the air pressure and the flow are used as state variables, the temperature of natural gas is generally used as a constant equal to the ambient temperature, and the thermodynamic process in a pipeline is ignored. The existing calculation method considering the pipeline thermal process uses the Weymouth equation as a flow model of the pipeline, but the contradiction is that the Weymouth equation is derived based on the assumption that the temperature of the whole pipeline is unchanged, so the calculation precision is limited in the context of considering the thermal process. In the research of the thermodynamic process specially aiming at the natural gas pipeline, the temperature distribution at different positions of the pipeline is generally described by using a Suhoff formula and the like, and the formula can account for the temperature change caused by the heat exchange between the natural gas and the external environment and the friction of the gas along the pipeline. When the distribution of the temperature and the pressure of the natural gas in the pipeline is expected to be observed simultaneously, a group of partial differential equations reflecting the flow characteristics of the gas in the pipeline is generally used, and the solution is carried out by numerical calculation methods such as finite difference approximation, a Roger-Kutta method and the like, so that the temperature and the pressure state of any point in the pipeline can be obtained.
The pipeline flow model in the partial differential form is not suitable for solving the unified energy flow of the electricity-gas integrated energy system because the pipeline flow model covers a large amount of unnecessary state variable information in the pipeline, thereby bringing huge calculation amount. In addition, the compressor is another important device of the natural gas system, the thermodynamic process of the compressor causes the obvious temperature rise of the outlet node, and the characteristic is not considered in the existing unified power flow solving method of the electricity-gas integrated energy system.
Disclosure of Invention
The present invention is directed to solving the problems of the prior art.
The technical scheme adopted for achieving the purpose of the invention is that the unified energy flow calculation method of the electricity-gas integrated energy system considering the natural gas thermodynamic process mainly comprises the following steps:
1) and establishing an equipment model considering the thermodynamic process of the natural gas system. The plant model includes a natural gas pipeline model and a compressor model.
The natural gas pipeline model comprises a natural gas pipeline thermal model and a natural gas pipeline flow model. The compressor model includes a compressor thermodynamic model and a compressor flow model.
1.1) establishing a natural gas pipeline model mainly comprises the following steps:
1.1.1) Natural gas horizontal pipe m1n1The gas flow conservation equation of (a) is as follows:
Figure GDA0002582685060000021
wherein p and T are the pressure and temperature of the natural gas, respectively. Z and R are the compressibility factor and gas constant of natural gas, respectively. λ is the coefficient of friction. x is the distance between the current position and the beginning of the pipe.
Figure GDA0002582685060000022
And
Figure GDA0002582685060000023
respectively the inner diameter and the cross-sectional area of the pipe.
Figure GDA0002582685060000024
Is the mass flow through the pipe. d (-) is the differential sign.
1.1.2) the natural gas temperature T (x) at a distance x from the pipeline starting point position is as follows:
Figure GDA0002582685060000025
in the formula, amnTo calculate the coefficients. T issIs ambient temperature. T ism1For the purpose of connecting with the natural gas system node m1The temperature of the outflowing natural gas. EtaJTIs the joule-thomson coefficient. p is a radical ofm1And pn1Respectively being the first node m in the branch of the natural gas pipeline1And end node n1The air pressure of (a).
Figure GDA0002582685060000026
Is a natural gas pipeline m1n1Length of (d).
Wherein the conversion coefficient
Figure GDA0002582685060000027
As follows:
Figure GDA0002582685060000028
in the formula (I), the compound is shown in the specification,
Figure GDA0002582685060000029
is a natural gas pipeline m1n1The heat transfer coefficient of (1). Rho0Is the density of natural gas in the standard state. CpIs the constant pressure heat capacity of natural gas.
Figure GDA00025826850600000210
Is flowed throughNatural gas pipeline m1n1The volume flow rate at the standard state of (1).
Figure GDA00025826850600000211
Is a natural gas pipeline m1n1Of the inner diameter of (a).
1.1.3) the natural gas temperature T is taken as a state variable, equation 1 is rewritten as follows:
Figure GDA0002582685060000031
1.1.4) substituting equations 2 and 3 into equation 4 yields:
Figure GDA0002582685060000032
1.1.5) the conversion of volume flow to mass flow under standard conditions is as follows:
Figure GDA0002582685060000033
the gas constant R is as follows:
Figure GDA0002582685060000034
1.1.6) substituting equation 6 and equation 7 into equation 5, a pipeline flow model in algebraic form suitable for non-isothermal conditions is obtained, namely:
Figure GDA0002582685060000035
in the formula, T0Is the natural gas temperature at standard conditions. p is a radical of0Is the natural gas pressure in the standard state. λ is the coefficient of friction.
1.1.7) pipeline thermodynamic model, i.e. natural gas pipeline m, according to equation 51n1Gas temperature at outletDegree of rotation
Figure GDA0002582685060000036
The calculation formula of (a) is as follows:
Figure GDA0002582685060000037
1.2) compressor thermodynamic model as follows:
Figure GDA0002582685060000038
in the formula, Tm2For compressor node m from natural gas system2The temperature of the outflowing natural gas.
Figure GDA0002582685060000039
Is a compressor m2n2The gas temperature at the outlet. p is a radical ofm2And pn2Respectively a first node m in a branch of the natural gas compressor2And end node n2The air pressure of (a). Chi shapem2n2Is a polytropic exponent.
The compressor flow rate model is shown in equations 11 to 12:
Figure GDA00025826850600000310
in the formula (I), the compound is shown in the specification,
Figure GDA00025826850600000311
the energy consumed for the compressor.
Figure GDA00025826850600000312
A constant related to the operation efficiency is consumed for the compressor.
Figure GDA0002582685060000041
Is the flow through the compressor.
Figure GDA0002582685060000042
In the formula (I), the compound is shown in the specification,
Figure GDA0002582685060000043
the flow consumed by the compressor.
Figure GDA0002582685060000044
And
Figure GDA0002582685060000045
respectively, the energy conversion parameters of the compressor.
2) And establishing a unified energy flow solving model of the electricity-gas integrated energy system based on the equipment model.
The unified energy flow solving model of the electricity-gas comprehensive energy system comprises a natural gas system model, an electric power system model and a coupling element model.
The natural gas system model comprises a thermodynamic balance model of natural gas system nodes and a flow balance model of the natural gas system nodes.
The thermodynamic balance of the natural gas system node is as follows:
Figure GDA0002582685060000046
in the formula, m ∈ n indicates that the node m is adjacent to the node n. FG,nAnd TG,nThe injection flow rate of the gas source at the node n of the natural gas system and the temperature of the natural gas of the gas source are respectively. m is m1,m2。n＝n1，n2。
Sign function sgn1The values of (m, n) are as follows:
Figure GDA0002582685060000047
the flow balance model of the natural gas system node is as follows:
Figure GDA0002582685060000048
in the formula, FD,nAnd FGAS,nRespectively the normal gas load at natural gas system node n and the gas flow consumed by the gas turbine. N is a radical ofmIs the total number of natural gas system nodes.
Sign function sgn2The values of (m, n) are as follows:
Figure GDA0002582685060000049
the power system model comprises an active power balance equation and a reactive power balance equation of the power system nodes.
The active power balance equation of the nodes of the power system is as follows:
Figure GDA0002582685060000051
in the formula, PG,iAnd PGAS,iThe active power output of the conventional unit and the gas turbine of the power system node i. PD,iIs the common active load of the node i of the power system.
The reactive power balance equation of the nodes of the power system is as follows:
Figure GDA0002582685060000052
in the formula, QG,iAnd QGAS,iRespectively the reactive power output of the conventional unit and the gas turbine of the power system node i. QD,iIs the common reactive load of the node i of the power system. QC,iThe output of the parallel reactive power compensation device of the node i of the power system. ViAnd thetaiRespectively, the voltage amplitude and the phase angle of the power system node i. GijAnd BijThe real part and the imaginary part of the ith row and the jth column element of the node admittance matrix. N is a radical ofeIs the total number of nodes in the power system. ThetaijIs a power system node i andphase angle difference of power system node j.
The energy conversion model of the coupling element gas turbine is as follows:
Figure GDA0002582685060000053
in the formula, GHV is high heating value of natural gas. Alpha is alphai,n、βi,nAnd gammai,nIs the energy conversion parameter of the gas turbine connecting the power system node i and the natural gas system node n.
3) And calculating the energy flow of the to-be-detected electricity-gas comprehensive energy system by using the unified energy flow solving model of the electricity-gas comprehensive energy system.
The technical effect of the present invention is undoubted. The invention provides a novel unified energy flow solving method which can more accurately reflect the temperature change condition of natural gas caused by a thermodynamic process and the influence of the temperature change condition on other state variables in a system.
Drawings
FIG. 1 is a schematic diagram of a 13-node natural gas system;
fig. 2 is a diagram showing the judgment of hydrate formation at a node.
Detailed Description
The present invention is further illustrated by the following examples, but it should not be construed that the scope of the above-described subject matter is limited to the following examples. Various substitutions and alterations can be made without departing from the technical idea of the invention and the scope of the invention is covered by the present invention according to the common technical knowledge and the conventional means in the field.
Example 1:
the unified energy flow calculation method of the electricity-gas comprehensive energy system considering the natural gas thermodynamic process mainly comprises the following steps of:
1) and establishing an equipment model considering the thermodynamic process of the natural gas system. The plant model includes a natural gas pipeline model and a compressor model.
The natural gas pipeline model comprises a natural gas pipeline thermal model and a natural gas pipeline flow model. The compressor model includes a compressor thermodynamic model and a compressor flow model.
1.1) establishing a natural gas pipeline model mainly comprises the following steps:
1.1.1) Natural gas horizontal pipe m1n1The gas flow conservation (conservation of mass, conservation of momentum, conservation of energy) equation is as follows:
Figure GDA0002582685060000061
wherein p and T are the pressure and temperature of the natural gas, respectively. Z and R are the compressibility factor and gas constant of natural gas, respectively. λ is the coefficient of friction. x is the distance between the current position and the beginning of the pipe.
Figure GDA0002582685060000062
And
Figure GDA0002582685060000063
respectively the inner diameter and the cross-sectional area of the pipe.
Figure GDA0002582685060000064
Is the mass flow through the pipe. d (-) is the differential sign.
1.1.2) the natural gas temperature T (x) at a distance x from the pipeline starting point position is as follows:
Figure GDA0002582685060000065
in the formula (I), the compound is shown in the specification,
Figure GDA0002582685060000066
to calculate the coefficients. T issIs ambient temperature. T ismIs the temperature of the natural gas flowing from the natural gas system node m. EtaJTIs the joule-thomson coefficient. p is a radical ofm1And pn1Respectively being the first node m in the branch of the natural gas pipeline1And end node n1The air pressure of (a).
Figure GDA0002582685060000067
Is a natural gas pipeline m1n1Length of (d).
In calculating equation 2, the third term on the right side can be ignored since its value is much smaller than the first two terms.
Wherein the conversion coefficient
Figure GDA0002582685060000068
As follows:
Figure GDA0002582685060000069
in the formula (I), the compound is shown in the specification,
Figure GDA00025826850600000610
is a natural gas pipeline m1n1The heat transfer coefficient of (1). Rho0Is the density of natural gas in the standard state. CpIs the constant pressure heat capacity of natural gas.
Figure GDA00025826850600000611
For flowing through natural gas pipeline m1n1The volume flow rate at the standard state of (1).
Figure GDA00025826850600000612
Is a natural gas pipeline m1n1Of the inner diameter of (a).
1.1.3) the natural gas temperature T is taken as a state variable, equation 1 is rewritten as follows:
Figure GDA0002582685060000071
1.1.4) substituting equations 2 and 3 into equation 4 yields:
Figure GDA0002582685060000072
1.1.5) the conversion of volume flow to mass flow under standard conditions is as follows:
Figure GDA0002582685060000073
the gas constant R is as follows:
Figure GDA0002582685060000074
1.1.6) substituting equation 6 and equation 7 into equation 5, a pipeline flow model in algebraic form suitable for non-isothermal conditions is obtained, namely:
Figure GDA0002582685060000075
in the formula, T0Is the natural gas temperature at standard conditions. p is a radical of0Is the natural gas pressure in the standard state. λ is the coefficient of friction. p is a radical of0＝101.325kPa,T0＝293.15K。
1.1.7) thermodynamic model, i.e. natural gas pipeline m, according to equation 51n1Temperature of gas at outlet
Figure GDA0002582685060000076
The calculation formula of (a) is as follows:
Figure GDA0002582685060000077
1.2) compressor thermodynamic model as follows:
Figure GDA0002582685060000078
in the formula, Tm2For compressor node m from natural gas system2The temperature of the outflowing natural gas.
Figure GDA0002582685060000079
Is a compressor m2n2The gas temperature at the outlet. p is a radical ofm2And pn2Respectively a first node m in a branch of the natural gas compressor2And end node n2The air pressure of (a). Chi shapem2n2Is a polytropic exponent that indicates that the actual thermodynamic process of the compressor is between two ideal conditions (adiabatic compression and isothermal compression).
The compressor flow rate model is shown in equations 11 to 12:
Figure GDA0002582685060000081
in the formula (I), the compound is shown in the specification,
Figure GDA0002582685060000082
the energy consumed for the compressor.
Figure GDA0002582685060000083
A constant related to the operation efficiency is consumed for the compressor.
Figure GDA0002582685060000084
Is the flow through the compressor.
Figure GDA0002582685060000085
In the formula (I), the compound is shown in the specification,
Figure GDA0002582685060000086
the flow consumed by the compressor.
Figure GDA0002582685060000087
And
Figure GDA0002582685060000088
respectively, the energy conversion parameters of the compressor.
2) And establishing a unified energy flow solving model of the electricity-gas integrated energy system based on the equipment model.
The unified energy flow solving model of the electricity-gas comprehensive energy system comprises a natural gas system model, an electric power system model and a coupling element model.
The natural gas system model comprises a thermodynamic balance model of natural gas system nodes and a flow balance model of the natural gas system nodes.
Thermodynamic equilibrium reflects the fact that the temperature of the natural gas flowing out of a node is a weighted average of the temperature of the gases flowing into the end of each branch of the node. The flow balance indicates that the natural gas flow into a node and out of it should be equal.
The thermodynamic balance of the natural gas system node is as follows:
Figure GDA0002582685060000089
in the formula, m ∈ n indicates that the node m is adjacent to the node n. FG,nAnd TG,nThe injection flow rate of the gas source at the node n of the natural gas system and the temperature of the natural gas of the gas source are respectively. m is m1,m2。n＝n1，n2。m1And n1Denotes a natural gas pipeline node, m2And n2Showing the natural gas compressor node.
The values of m and n include the following two groups: 1) m is m1And n is equal to n1。2)m＝m2And n is equal to n2。
When m is equal to m1And n is equal to n1Meanwhile, a natural gas pipeline node solving model of the electricity-gas integrated energy system is established. When m is equal to m2And n is equal to n2Meanwhile, a natural gas compressor node solving model of the electricity-gas integrated energy system is established.
Sign function sgn1The values of (m, n) are as follows:
Figure GDA0002582685060000091
the flow balance model of the natural gas system node is as follows:
Figure GDA0002582685060000092
in the formula, FD,nAnd FGAS,nRespectively the normal gas load at natural gas system node n and the gas flow consumed by the gas turbine. N is a radical ofmIs the total number of natural gas system nodes.
Sign function sgn2The values of (m, n) are as follows:
Figure GDA0002582685060000093
the power system model comprises an active power balance equation and a reactive power balance equation of the power system nodes.
The active power balance equation of the nodes of the power system is as follows:
Figure GDA0002582685060000094
in the formula, PG,iAnd PGAS,iThe active power output of the conventional unit and the gas turbine of the power system node i. PD,iIs the common active load of the node i of the power system.
The reactive power balance equation of the nodes of the power system is as follows:
Figure GDA0002582685060000095
in the formula, QG,iAnd QGAS,iRespectively the reactive power output of the conventional unit and the gas turbine of the power system node i. QD,iIs the common reactive load of the node i of the power system. QC,iThe output of the parallel reactive power compensation device of the node i of the power system. ViAnd thetaiRespectively, the voltage amplitude and the phase angle of the power system node i. GijAnd BijThe real part and the imaginary part of the ith row and the jth column element of the node admittance matrix.NeIs the total number of nodes in the power system. ThetaijIs the phase angle difference between power system node i and power system node j.
The energy conversion model of the coupling element gas turbine is as follows:
Figure GDA0002582685060000096
in the formula, GHV is high heating value of natural gas. Alpha is alphai,n、βi,nAnd gammai,nIs the energy conversion parameter of the gas turbine connecting the power system node i and the natural gas system node n.
3) And calculating the energy flow of the to-be-detected electricity-gas comprehensive energy system by using the unified energy flow solving model of the electricity-gas comprehensive energy system. The unified energy flow model of the built electricity-gas integrated energy system is a group of models with X ═ thetai,Vi,πm,,Tm]TAs a non-linear equation for the system state variables. An efficient solution of the model can be achieved using the newton-raphson method.
Example 2:
an experiment for verifying a unified energy flow calculation method of an electricity-gas integrated energy system considering a natural gas thermal process mainly comprises the following steps of:
1) a test system as shown in fig. 1 was set up.
Taking an IEEE14-NGS13 system, namely an IEEE14 node system and a 13 node natural gas system as an example, the method for calculating the unified energy flow of the electricity-gas comprehensive energy system considering the thermodynamic process of a pipeline and a compressor, which is provided by the invention, is tested. The 13-node natural gas system comprises 2 gas sources, 3 common loads, 9 pipelines, 3 compressors and 2 gas turbines. Wherein all compressors are driven by natural gas. Connected to the 2 gas turbines are node 1 (balance node) of the power system and node 8 of the natural gas system, and node 3 of the power system and node 6 of the natural gas system, respectively. A schematic diagram of which is shown in fig. 1.
2) Different comparison models
In order to verify the effectiveness of the unified energy flow calculation method of the electricity-gas comprehensive energy system considering the thermodynamic process of the natural gas equipment, the following 2 models are adopted for comparison:
m1: the existing electricity-gas integrated energy system unified energy flow model considering the pipeline thermal process.
M2: the invention provides a unified energy flow calculation model of an electricity-gas integrated energy system considering a natural gas thermal process.
3) Validation of pipeline flow model and compressor thermodynamic model
TABLE 1 results of air temperature and pressure calculations for M1 and M2 nodes
Figure GDA0002582685060000101
Table 1 shows the calculation results of the air temperature and the air pressure when the unified power flow solving calculation of the electrical-electrical interconnection system is performed by using M1 and M2, respectively.
As can be seen from Table 1, the calculation results obtained by using the model provided by the invention are significantly different from those obtained by using the existing model. For the air temperature, the difference between the calculation results of the two models exceeds 5K at nodes 2, 3, 5, 9 and 10, and the positions of the nodes are relatively close to the compressor. The difference is mainly caused by different treatment modes of the temperatures of the nodes at the head end and the tail end of the compressor. For M1, the temperature at the nodes at the head and tail ends of the compressor is considered to be a constant equal to the temperature of the air supply. For M2, the temperature of the nodes at the head end and the tail end of the compressor is calculated according to a corresponding model, and the value of the temperature can be greatly different from the temperature of the air supply. On the other hand, when the pipeline is long enough, the temperature of the natural gas at the tail end of the pipeline is close to the ambient temperature, so that the difference of the temperature calculation results of the two models is small for the node far away from the compressor. For the air pressure, the difference of the results calculated by adopting the two models is also obvious, the difference reaches 16.45psi at the node 13, because the state variables such as the air temperature, the air pressure and the like of each node have close coupling relation, the difference of the calculation results of any variable can bring influence to the calculation results of other variables, and the working value of the invention is also obvious.
Based on the poilmaloff empirical formula, whether the hydrate is generated can be judged by integrating the node air temperature and the node air pressure, as shown in fig. 2. When the node temperature is low and the gas pressure is high (corresponding to the upper left part of fig. 2), hydrates are generated.

Claims (6)

1. The unified energy flow calculation method of the electricity-gas integrated energy system considering the natural gas thermodynamic process is characterized by mainly comprising the following steps of:
1) establishing an equipment model considering the thermodynamic process of a natural gas system; the equipment model comprises a natural gas pipeline model and a compressor model;
the natural gas pipeline model comprises a natural gas pipeline thermal model and a natural gas pipeline flow model; the compressor model comprises a compressor thermal model and a compressor flow model;
a natural gas pipeline model is established, and the method mainly comprises the following steps:
1.1) Natural gas horizontal pipe m1n1The gas flow conservation equation of (a) is as follows:
Figure FDA0002677575520000011
wherein p and T are the pressure and temperature of the natural gas, respectively; z and R are respectively a compression factor and a gas constant of the natural gas; λ is the coefficient of friction; x is the distance between the current position and the starting point of the pipeline;
Figure FDA0002677575520000012
and
Figure FDA0002677575520000013
the inner diameter and the sectional area of the pipeline are respectively;
Figure FDA0002677575520000014
is the mass flow through the pipe; d (-) is the differential sign;
1.2) the natural gas temperature T (x) at a distance x from the pipeline starting point is as follows:
Figure FDA0002677575520000015
in the formula (I), the compound is shown in the specification,
Figure FDA0002677575520000016
to calculate the coefficients; t issIs ambient temperature; t ism1For the purpose of connecting with the natural gas system node m1The temperature of the outflowing natural gas; etaJTIs the joule-thomson coefficient; p is a radical ofm1And pn1Respectively being the first node m in the branch of the natural gas pipeline1And end node n1The air pressure of (a);
Figure FDA0002677575520000017
is a natural gas pipeline m1n1Length of (d);
wherein the coefficients are calculated
Figure FDA0002677575520000018
As follows:
Figure FDA0002677575520000019
in the formula (I), the compound is shown in the specification,
Figure FDA00026775755200000110
is a natural gas pipeline m1n1Heat transfer coefficient of (d); rho0Density of natural gas in a standard state; cpIs the constant pressure heat capacity of natural gas;
Figure FDA00026775755200000111
for flowing through natural gas pipeline m1n1The volume flow rate in the standard state of (1);
Figure FDA00026775755200000112
is a natural gas pipeline m1n1Inner diameter of (d);
1.3) taking the natural gas temperature T as the state variable, equation (1) is rewritten as follows:
Figure FDA00026775755200000113
1.4) substituting equation (2) and equation (3) into equation (4) yields:
Figure FDA0002677575520000021
1.5) the conversion relationship between volume flow and mass flow under the standard state is as follows:
Figure FDA0002677575520000022
the gas constant R is as follows:
Figure FDA0002677575520000023
1.6) substituting the formula (6) and the formula (7) into the formula (5) to obtain an algebraic pipeline flow model suitable for non-isothermal conditions, namely:
Figure FDA0002677575520000024
in the formula, T0Is the natural gas temperature at standard conditions; p is a radical of0Natural gas pressure under standard state; λ is the coefficient of friction;
1.7) pipeline thermodynamic model, i.e. natural gas pipeline m, according to equation (2)1n1Temperature of gas at outlet
Figure FDA0002677575520000025
The calculation formula of (a) is as follows:
Figure FDA0002677575520000026
2) establishing a unified energy flow solving model of the electricity-gas integrated energy system based on the equipment model;
the unified energy flow solving model of the electricity-gas integrated energy system comprises a natural gas system model, an electric power system model and a coupling element model;
3) and calculating the energy flow of the to-be-detected electricity-gas comprehensive energy system by using the unified energy flow solving model of the electricity-gas comprehensive energy system.
2. The method for calculating the unified power flow of an electric-gas integrated energy system considering the thermodynamic process of natural gas as claimed in claim 1, wherein the thermodynamic model of the compressor is as follows:
Figure FDA0002677575520000027
in the formula, Tm2For compressor node m from natural gas system2The temperature of the outflowing natural gas;
Figure FDA0002677575520000028
is a compressor m2n2The temperature of the gas at the outlet; p is a radical ofm2And pn2Respectively a first node m in a branch of the natural gas compressor2And end node n2The air pressure of (a);
Figure FDA0002677575520000029
is a polytropic exponent.
3. The method for calculating the unified power flow of an electric-gas integrated energy system considering the thermodynamic process of natural gas according to claim 1, wherein the compressor flow models are respectively as shown in equations (11) to (12):
Figure FDA0002677575520000031
in the formula (I), the compound is shown in the specification,
Figure FDA0002677575520000032
energy consumed for the compressor;
Figure FDA0002677575520000033
consuming a constant related to the working efficiency for the compressor;
Figure FDA0002677575520000034
is the flow through the compressor;
Figure FDA0002677575520000035
in the formula (I), the compound is shown in the specification,
Figure FDA0002677575520000036
the flow rate consumed for the compressor;
Figure FDA0002677575520000037
and
Figure FDA0002677575520000038
respectively, the energy conversion parameters of the compressor.
4. The method for calculating the unified power flow of the electricity-gas integrated energy system considering the natural gas thermodynamic process according to claim 1, wherein the natural gas system model comprises a thermodynamic balance model of natural gas system nodes and a flow balance model of natural gas system nodes;
the thermodynamic balance of the natural gas system node is as follows:
Figure FDA0002677575520000039
in the formula, m belongs to n and represents that the node m is adjacent to the node n; fG,nAnd TG,nRespectively injecting the flow rate of the gas source of the natural gas system node n and the temperature of the natural gas of the gas source; m is m1,m2；n＝n1，n2；
Sign function sgn1The values of (m, n) are as follows:
Figure FDA00026775755200000310
the flow balance model of the natural gas system node is as follows:
Figure FDA00026775755200000311
in the formula, FD,nAnd FGAS,nRespectively the normal gas load of the natural gas system node n and the gas flow consumed by the gas turbine; n is a radical ofmThe total number of natural gas system nodes;
sign function sgn2The values of (m, n) are as follows:
Figure FDA00026775755200000312
5. the method for calculating the unified power flow of an electricity-gas integrated energy system considering the thermodynamic process of natural gas as claimed in claim 1, wherein the power system model comprises a power system node active power balance equation and a reactive power balance equation;
the active power balance equation of the nodes of the power system is as follows:
Figure FDA0002677575520000041
in the formula, PG,iAnd PGAS,iThe active power output of a conventional unit and a gas turbine which are nodes i of the power system; pD,iIs the common active load of the node i of the power system;
the reactive power balance equation of the nodes of the power system is as follows:
Figure FDA0002677575520000042
in the formula, QG,iAnd QGAS,iThe reactive power output of the conventional unit and the gas turbine of the power system node i is respectively; qD,iIs the common reactive load of the node i of the power system; qC,iThe output of the parallel reactive power compensation device of the node i of the power system; viAnd thetaiThe voltage amplitude and the phase angle of a node i of the power system are respectively; gijAnd BijReal and imaginary parts of the jth column element of the ith row of the node admittance matrix; n is a radical ofeThe total number of the nodes of the power system is; thetaijIs the phase angle difference between power system node i and power system node j.
6. The method for calculating the unified power flow of an electricity-gas integrated energy system considering the thermodynamic process of natural gas as claimed in claim 1, wherein the energy conversion model of the coupling element gas turbine is as follows:
Figure FDA0002677575520000043
in the formula, GHV is high heat value of natural gas; alpha is alphai,n、βi,nAnd gammai,nIs the energy conversion parameter of the gas turbine connecting the power system node i and the natural gas system node n.
CN201811633610.XA 2018-12-29 2018-12-29 Unified energy flow calculation method of electricity-gas comprehensive energy system considering natural gas thermal process Active CN109740242B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811633610.XA CN109740242B (en) 2018-12-29 2018-12-29 Unified energy flow calculation method of electricity-gas comprehensive energy system considering natural gas thermal process

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811633610.XA CN109740242B (en) 2018-12-29 2018-12-29 Unified energy flow calculation method of electricity-gas comprehensive energy system considering natural gas thermal process

Publications (2)

Publication Number Publication Date
CN109740242A CN109740242A (en) 2019-05-10
CN109740242B true CN109740242B (en) 2020-11-24

Family

ID=66362208

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811633610.XA Active CN109740242B (en) 2018-12-29 2018-12-29 Unified energy flow calculation method of electricity-gas comprehensive energy system considering natural gas thermal process

Country Status (1)

Country Link
CN (1) CN109740242B (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110765622A (en) * 2019-10-28 2020-02-07 南方电网科学研究院有限责任公司 Energy flow obtaining system, equipment and medium of natural gas pipeline model
CN110991061B (en) * 2019-12-10 2023-07-07 国网浙江省电力有限公司杭州供电公司 Thermoelectric comprehensive energy simulation planning method
CN111259547B (en) * 2020-01-16 2021-12-03 清华大学 Natural gas path modeling method for operation control of comprehensive energy system
CN111682520B (en) * 2020-03-11 2023-08-22 国网辽宁省电力有限公司大连供电公司 Method for optimizing analysis of electric-gas interconnection system by using network flow
CN111563315B (en) * 2020-04-08 2024-01-26 重庆大学 Topology analysis-based steady-state energy flow calculation method for electric-gas comprehensive energy system
CN113343531B (en) * 2021-06-21 2023-04-18 华北电力大学 Method for acquiring dynamic energy flow of electricity-gas integrated energy system based on explicit difference

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105958480A (en) * 2016-05-27 2016-09-21 清华大学 Combined static safety analysis method for electrical-gas coupling multiple energy flow system
CN107730129A (en) * 2017-10-24 2018-02-23 重庆大学 Consider the electrical heat interacted system methods of risk assessment of photo-thermal cogeneration of heat and power and electric boiler
CN108599137A (en) * 2017-12-28 2018-09-28 东南大学 A kind of multipotency streaming system optimizing operation method considering region heat supply network transient state heat-transfer character

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012122004A2 (en) * 2011-03-04 2012-09-13 Hugo Ronald J Distributed compressed air energy storage system and method
CN107491849B (en) * 2017-10-09 2020-10-20 清华大学 Gas power plant gas storage capacity calculation method considering constraint of electricity-gas coupling system
CN108062599B (en) * 2017-12-12 2020-08-18 西安交通大学 Modeling method for cooperative operation of electric power system and natural gas system
CN108964143B (en) * 2018-06-28 2020-10-09 重庆大学 Natural gas network static equivalent model of electricity-gas comprehensive energy system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105958480A (en) * 2016-05-27 2016-09-21 清华大学 Combined static safety analysis method for electrical-gas coupling multiple energy flow system
CN107730129A (en) * 2017-10-24 2018-02-23 重庆大学 Consider the electrical heat interacted system methods of risk assessment of photo-thermal cogeneration of heat and power and electric boiler
CN108599137A (en) * 2017-12-28 2018-09-28 东南大学 A kind of multipotency streaming system optimizing operation method considering region heat supply network transient state heat-transfer character

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"A unified gas and power flow analysis in natural gas and electricity coupled networks";Alberto Martínez-Mares et al.;《IEEE TRANSACTIONS ON POWER SYSTEMS》;20121130;第27卷(第4期);第2156-2166页 *
"含电转气的电-气互联系统可靠性评估";余娟等;《中国电机工程学报》;20180205;第38卷(第3期);第708-715页 *
Alberto Martínez-Mares et al.."A unified gas and power flow analysis in natural gas and electricity coupled networks".《IEEE TRANSACTIONS ON POWER SYSTEMS》.2012,第27卷(第4期),第2156-2166页. *

Also Published As

Publication number Publication date
CN109740242A (en) 2019-05-10

Similar Documents

Publication Publication Date Title
CN109740242B (en) Unified energy flow calculation method of electricity-gas comprehensive energy system considering natural gas thermal process
CN109800968B (en) Power-gas interconnection system probability energy flow analysis method considering natural gas system thermodynamic process
CN109726483B (en) Radial heat supply network model of electric-heat interconnection comprehensive energy system and system thereof
CN106844895B (en) Decoupling calculation method for combined cooling heating and power micro-grid energy flow
Cheng et al. Bi-directional nozzle control of multistage radial-inflow turbine for optimal part-load operation of compressed air energy storage
Barbour et al. Why is adiabatic compressed air energy storage yet to become a viable energy storage option?
CN110866213A (en) Multi-network steady-state energy flow analysis method and device for electricity-gas integrated energy system
Li et al. Gradient descent iterative method for energy flow of integrated energy system considering multiple modes of compressors
Li et al. Graph theory-based heat current analysis method for supercritical CO2 power generation system
CN111563315B (en) Topology analysis-based steady-state energy flow calculation method for electric-gas comprehensive energy system
Kisha et al. Asymmetrically heated multi-stage travelling-wave thermoacoustic electricity generator
Lu et al. Dynamic modeling and numerical investigation of novel pumped thermal electricity storage system during startup process
Valdés et al. Reynolds-number-dependent efficiency characterization of a micro-scale centrifugal compressor using non-conventional working fluids
Shamekhi Amiri et al. Development of a Dynamic Model for Simulating the Transient Behaviour of a Solar-Powered Micro Gas Turbine
CN113420397B (en) Dynamic operation regulation and control method for energy storage power station
CN114629124A (en) Comprehensive energy system load flow calculation method based on subareas
Yao et al. A novel cross iteration method for dynamic energy flow calculation of the hot-water heating network in the integrated energy system
CN111241479A (en) Electric-thermal interconnection comprehensive energy system risk assessment method based on cross entropy and objective entropy weight method
Barberis et al. High temperature storage for CSP hybrid gas turbine: test rig dynamic analysis and experimental validation
Chen et al. Unsteady analysis of the cold energy storage heat exchanger in a liquid air energy storage system
CN117134418B (en) Load flow calculation method, device and equipment of multi-energy coupling system
Raggio et al. Compressed air energy storage with T100 microturbines: Dynamic analysis and operational constraints
Kuras Experimental Study of a Transcritical Thermoacoustic Engine with Power Extraction Applications
Wang et al. Performance Analysis of Distributed Compressed Air Energy Storage under Different Air Storage Chamber Models
Cui et al. Dynamic modeling and regulation control of advanced adiabatic compressed air energy storage under all operating conditions

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant