Efficiency calculation method and device for natural gas excess pressure power generation equipment

Abstract

The embodiment of the invention provides an efficiency calculation method and device for natural gas excess pressure power generation equipment. The method comprises the steps of obtaining operation data of the excess pressure power generation equipment; according to the operation data, the enthalpy value of natural gas at an inlet of the residual pressure power generation equipment and the enthalpy value of natural gas at an outlet are calculated; according to the operation data, the entropy value of natural gas at an inlet and the entropy value of natural gas at an outlet of the residual pressure power generation equipment are calculated; calculating ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment; and calculating the efficiency of the residual pressure power generation equipment according to the ideal work. According to the embodiment of the invention, the equipment efficiency of natural gas excess pressure power generation can be accurately calculated.

Description

Technical Field

[0001] The embodiments of the present specification relate to the field of power generation technology, and in particular, to a method and device for calculating the efficiency of a natural gas residual pressure power generation equipment. Background Art

[0002] The natural gas excess pressure power generation technology replaces the traditional pressure regulating valve with an expander, and uses the mechanical energy generated when high-pressure natural gas expands and reduces pressure to directly drive the generator to generate electricity. The natural gas in the high-pressure pipeline network is first preheated by the preheater and then enters the expander. After the pressure is reduced, it drives the generator set to generate electricity. It is then heated by the heater to prevent water condensation from blocking the pipeline. The heated natural gas is output to the low-pressure natural gas pipeline network. The natural gas excess pressure power generation system converts pressure energy into electrical energy and cold energy, so that the excess pressure resources are recovered.

[0003] With the promotion of natural gas excess pressure power generation technology and the construction of pilot projects, accurate calculation of the equipment efficiency of natural gas excess pressure power generation is a basic means to evaluate the quality of construction projects and improve the level of project management. It is also a method for comparing excess pressure power generation equipment based on different principles. It plays an important reference role in the analysis and selection of the operation of natural gas excess pressure power generation equipment, project management and natural gas excess pressure power generation equipment based on different principles.

[0004] Therefore, there is an urgent need for an efficiency calculation method for natural gas excess pressure power generation equipment, which can accurately calculate the equipment efficiency of natural gas excess pressure power generation. Summary of the invention

[0005] The purpose of the embodiments of this specification is to provide a method and device for calculating the efficiency of a natural gas excess pressure power generation device, so as to accurately calculate the efficiency of the natural gas excess pressure power generation device.

[0006] To achieve the above objectives, on the one hand, an embodiment of this specification provides a method for calculating the efficiency of a natural gas residual pressure power generation equipment, including:

[0007] Obtaining the operating data of the residual pressure power generation equipment;

[0008] Calculating the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data;

[0009] Calculating the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data;

[0010] Calculating the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment, and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment;

[0011] The efficiency of the residual pressure power generation equipment is calculated according to the ideal work.

[0012] Preferably, after obtaining the operating data of the residual pressure power generation equipment, the method further includes:

[0013] Calculating the critical temperature and critical pressure of the natural gas according to the critical temperatures and critical pressures of different components in the natural gas;

[0014] The relative temperature and relative pressure of the natural gas are calculated according to the critical temperature and the critical pressure.

[0015] Preferably, the step of calculating the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operating data further comprises:

[0016] According to the comparative temperature and comparative pressure of the natural gas, the influence of pressure on the enthalpy of simple fluid and the deviation of the influence of pressure on the enthalpy of real fluid and simple fluid are obtained by reading the graph;

[0017] The influence of pressure on the enthalpy of natural gas is calculated based on the influence of pressure on the enthalpy of simple fluid and the deviation of the influence of pressure on the enthalpy of real fluid and simple fluid;

[0018] Calculating the enthalpy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under the ideal gas state according to the enthalpy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under the ideal gas state;

[0019] According to the influence of the pressure on the enthalpy of natural gas and the enthalpy of the natural gas at the inlet and the natural gas at the outlet under ideal gas state, the enthalpy of the natural gas at the inlet and the enthalpy of the natural gas at the outlet of the residual pressure power generation equipment are calculated.

[0020] Preferably, the step of calculating the enthalpy values ​​of the natural gas at the inlet and the outlet of the residual pressure power generation equipment under an ideal gas state according to the enthalpy values ​​of different components in the natural gas at the inlet and the outlet under an ideal gas state further comprises:

[0021] The enthalpy values ​​of the natural gas at the inlet and outlet of the residual pressure power generation equipment under the ideal gas state are calculated by the following formula:

[0022]

[0023] in, is the enthalpy of the i-th component in natural gas under ideal gas state, y i is the molar percentage of the i-th component in natural gas, It is the enthalpy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment under ideal gas state.

[0024] Preferably, the step of calculating the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operating data further comprises:

[0025] According to the comparative temperature and comparative pressure of the natural gas, the influence of pressure on the entropy value of the simple fluid and the deviation of the influence of pressure on the entropy values ​​of the real fluid and the simple fluid are obtained by reading the graph;

[0026] The influence of pressure on the entropy value of natural gas is calculated based on the influence of pressure on the entropy value of simple fluid and the deviation of the influence of pressure on the entropy values ​​of real fluid and simple fluid;

[0027] Calculating the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under the ideal gas state according to the entropy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under the ideal gas state;

[0028] According to the influence of the pressure on the entropy value of natural gas and the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet under ideal gas state, the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment are calculated.

[0029] Preferably, the step of calculating the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under an ideal gas state according to the entropy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under an ideal gas state further comprises:

[0030] The entropy values ​​of the natural gas at the inlet and outlet of the residual pressure power generation equipment under the ideal gas state are calculated by the following formula:

[0031]

[0032] in, is the entropy value of the i-th component in natural gas under ideal gas state, y i is the molar percentage of the i-th component in natural gas, It is the entropy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment under the ideal gas state.

[0033] Preferably, the calculating the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment further comprises:

[0034] The ideal work of the residual pressure power generation equipment is calculated by the following formula:

[0035] W d =(H2-H1)-T0(S2-S1);

[0036] Among them, W d is the ideal work of the residual pressure power generation equipment, H2 is the enthalpy of natural gas at the outlet of the residual pressure power generation equipment, H1 is the enthalpy of natural gas at the inlet of the residual pressure power generation equipment, S2 is the entropy of natural gas at the outlet of the residual pressure power generation equipment, S1 is the entropy of natural gas at the inlet of the residual pressure power generation equipment, and T0 is the ground state temperature.

[0037] On the other hand, an embodiment of the present specification provides an efficiency calculation device for a natural gas residual pressure power generation equipment, the device comprising:

[0038] An acquisition module, used to acquire operation data of the residual pressure power generation equipment;

[0039] An enthalpy value calculation module, used to calculate the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data;

[0040] An entropy value calculation module, used to calculate the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data;

[0041] an ideal work calculation module, used to calculate the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment, and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment;

[0042] The efficiency calculation module is used to calculate the efficiency of the residual pressure power generation equipment according to the ideal work.

[0043] On the other hand, an embodiment of the present specification further provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein when the computer program is executed by the processor, the instructions of any one of the above methods are executed.

[0044] On the other hand, an embodiment of the present specification further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor of a computer device, the computer program executes instructions of any one of the above-described methods.

[0045] It can be seen from the technical solutions provided in the above embodiments of this specification that the efficiency calculation method of the excess pressure power generation equipment established by the embodiments of this specification can calculate the energy conversion efficiency of the excess pressure power generation equipment, and then intuitively judge the conversion capacity of the excess pressure power generation equipment to the natural gas pressure energy, thereby judging the operation status of the excess pressure power generation equipment, and providing a basis for the selection of excess pressure power generation equipment in the future natural gas project construction process and the acceptance of the excess pressure power generation equipment that has been put into production.

[0046] In order to make the above and other purposes, features and advantages of the present specification more obvious and easy to understand, the following specifically cites preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 A schematic flow chart showing a method for calculating the efficiency of a natural gas residual pressure power generation device provided in an embodiment of this specification is shown;

[0049] Figure 2 A schematic diagram of a process after obtaining the operating data of the residual pressure power generation equipment provided in the embodiment of this specification is shown;

[0050] Figure 3 A schematic diagram of a process flow for reflecting the influence of pressure on the enthalpy value of a simple fluid provided in an embodiment of this specification is shown;

[0051] Figure 4 A schematic diagram for reflecting the influence of pressure on the enthalpy values ​​of real fluids and simple fluids provided in the embodiments of this specification is shown;

[0052] Figure 5 A schematic diagram of calculating the enthalpy value of natural gas at the inlet and the enthalpy value of natural gas at the outlet of a residual pressure power generation device provided in an embodiment of this specification is shown;

[0053] Figure 6 A schematic diagram showing the coefficients of thermodynamic equations under an ideal gas state provided in an embodiment of this specification is shown;

[0054] Figure 7 A schematic diagram for reflecting the effect of pressure on the entropy value of a simple fluid provided in an embodiment of this specification is shown;

[0055] Figure 8 A schematic diagram for reflecting the influence of pressure on the entropy value of a real fluid and a simple fluid provided in an embodiment of this specification is shown;

[0056] Fig. 9 A schematic diagram of a process for calculating the entropy value of natural gas at the inlet and the outlet of a residual pressure power generation device provided in an embodiment of this specification is shown;

[0057] Fig.10A schematic diagram of the module structure of an efficiency calculation device for a natural gas residual pressure power generation equipment provided in an embodiment of this specification is shown;

[0058] Fig.11 A schematic diagram of the structure of a computer device provided in an embodiment of this specification is shown.

[0059] Description of the accompanying symbols:

[0060] 100. Get module;

[0061] 200. Enthalpy calculation module;

[0062] 300. Entropy value calculation module;

[0063] 400. Ideal work calculation module;

[0064] 500. Efficiency calculation module;

[0065] 1102. Computer equipment;

[0066] 1104. Processor;

[0067] 1106. Memory;

[0068] 1108. Driving mechanism;

[0069] 1110, input / output module;

[0070] 1112. Input device;

[0071] 1114. Output device;

[0072] 1116. Presentation equipment;

[0073] 1118. Graphical user interface;

[0074] 1120, network interface;

[0075] 1122. Communication link;

[0076] 1124. Communication bus. DETAILED DESCRIPTION

[0077] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of this specification.

[0078] With the promotion of natural gas excess pressure power generation technology and the construction of pilot projects, accurate calculation of the equipment efficiency of natural gas excess pressure power generation is a basic means to evaluate the quality of construction projects and improve the level of project management. It is also a method for comparing excess pressure power generation equipment based on different principles. It plays an important reference role in the analysis and selection of the operation of natural gas excess pressure power generation equipment, project management and natural gas excess pressure power generation equipment based on different principles.

[0079] In order to solve the above problems, an embodiment of the present specification provides a method for calculating the efficiency of a natural gas residual pressure power generation equipment. Figure 1 This is a flow chart of a method for calculating the efficiency of a natural gas residual pressure power generation equipment provided in an embodiment of this specification. This specification provides method operation steps as described in the embodiment or flow chart, but may include more or fewer operation steps based on conventional or non-creative labor. The order of steps listed in the embodiment is only one way of executing the order of many steps and does not represent the only execution order. When the system or device product is executed in practice, it can be executed in the order of the method shown in the embodiment or the accompanying drawings or in parallel.

[0080] It should be noted that the terms "first", "second", etc. in the description and claims of the embodiments of this specification and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of this specification described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, device, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0081] Reference Figure 1 The present specification provides a method for calculating the efficiency of a natural gas residual pressure power generation device, including:

[0082] S101: Acquire operation data of the residual pressure power generation equipment;

[0083] S102: Calculating the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data;

[0084] S103: Calculating the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data;

[0085] S104: calculating the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment, and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment;

[0086] S105: Calculating the efficiency of the residual pressure power generation equipment according to the ideal work.

[0087] The operating data of the excess pressure power generation equipment is acquired on-site. Specifically, after the excess pressure power generation equipment has been running stably for 1 hour, first parameters such as the natural gas temperature at the inlet of the excess pressure power generation equipment, the natural gas temperature at the outlet, the natural gas pressure at the inlet, the natural gas pressure at the outlet, and the natural gas composition are acquired. The first parameters can be acquired multiple times during the acquisition, and then the average value of the multiple acquisitions is calculated as the operating data to reduce the occurrence of inaccurate operating data caused by only one acquisition.

[0088] In addition to the first parameter, the embodiment of this specification also obtains second parameters such as the power generation and natural gas flow of the residual pressure power generation equipment. The second parameter is calculated as a cumulative value by multiple acquisitions of the first parameter. For example, the first parameter is calculated as the average value of 4 acquisitions, and the second parameter is calculated as the cumulative value of 4 acquisitions.

[0089] Further based on the operating data, the enthalpy value of the natural gas at the inlet of the excess pressure power generation equipment, the enthalpy value of the natural gas at the outlet, the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet are calculated to calculate the ideal work of the excess pressure power generation equipment, and then based on the ideal work, the efficiency of the excess pressure power generation equipment is calculated.

[0090] By using the efficiency calculation method of the excess pressure power generation equipment established in the embodiments of this specification, the energy conversion efficiency of the excess pressure power generation equipment can be calculated, and then the conversion capacity of the excess pressure power generation equipment to the natural gas pressure energy can be intuitively judged, thereby judging the operation status of the excess pressure power generation equipment, providing a basis for the selection of excess pressure power generation equipment in the future natural gas project construction process and the acceptance of the excess pressure power generation equipment that has been put into production.

[0091] In the embodiments of this specification, refer to Figure 2 , after obtaining the operation data of the residual pressure power generation equipment, the method further includes:

[0092] S201: Calculating the critical temperature and critical pressure of the natural gas according to the critical temperatures and critical pressures of different components in the natural gas;

[0093] S202: Calculate the comparative temperature and comparative pressure of the natural gas according to the critical temperature and critical pressure.

[0094] Specifically, the critical temperature and critical pressure of natural gas are calculated by the following formula:

[0095] T c =∑y i T ci ;

[0096] P c =∑y i P ci ;

[0097] Among them, T c is the critical temperature of natural gas, y i is the molar percentage of the i-th component in natural gas, T ci is the critical temperature of the i-th component in natural gas, P c is the critical pressure of natural gas, P ci is the critical pressure of the i-th component in natural gas.

[0098] The relative temperature and relative pressure of natural gas are further calculated by the following formula:

[0099]

[0100]

[0101] Among them, T r is the relative temperature of natural gas, T is the natural gas temperature at the inlet or outlet of the residual pressure power generation equipment, P r is the relative pressure of natural gas, and P is the natural gas pressure at the inlet or outlet of the residual pressure power generation equipment.

[0102] In the embodiments of this specification, refer to Figure 5 , the step of calculating the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operating data further comprises:

[0103] S301: According to the comparative temperature and comparative pressure of the natural gas, read the graph to obtain the influence of pressure on the enthalpy value of the simple fluid, and the influence deviation of pressure on the enthalpy values ​​of the real fluid and the simple fluid;

[0104] Reference Figure 3 and Figure 4 , Figure 3 The figure shows the effect of pressure on the enthalpy of a simple fluid. Figure 4 The figure shows the effect of pressure on the enthalpy of real fluid and simple fluid. After knowing the comparative temperature and comparative pressure of natural gas, the comprehensive comparative temperature T r and the contrast pressure P r , by reading Figure 3 , the vertical coordinate value obtained The effect of pressure on the enthalpy of a simple fluid, compared with temperature T r and the contrast pressure P r , by reading Figure 4 , the vertical coordinate value obtained is the deviation of the effect of pressure on the enthalpy of real fluid and simple fluid.

[0105] S302: Calculate the influence of pressure on the enthalpy value of natural gas according to the influence of pressure on the enthalpy value of simple fluid and the deviation of the influence of pressure on the enthalpy values ​​of real fluid and simple fluid;

[0106] The influence of pressure on the enthalpy of natural gas is calculated by the following formula:

[0107]

[0108] in, is the effect of pressure on the enthalpy of natural gas, is the effect of pressure on the enthalpy of a simple fluid, is the deviation of the effect of pressure on the enthalpy of real fluid and simple fluid, ω m is the eccentricity factor of natural gas, R is the gas constant, R = 8.3145 kJ / (kmol·K), T c is the critical temperature of natural gas.

[0109] Specific:

[0110] ω m =∑y i ω i (4)

[0111] Among them, y i is the molar percentage of the i-th component in natural gas, ω i is the eccentricity factor of the i-th component in natural gas, with a dimension of 1.

[0112] S303: Calculating the enthalpy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under the ideal gas state according to the enthalpy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under the ideal gas state;

[0113] Specifically, the enthalpy values ​​of the natural gas at the inlet and outlet of the residual pressure power generation equipment under the ideal gas state are calculated by the following formula:

[0114]

[0115] in, is the enthalpy of the i-th component in natural gas under ideal gas state, y i is the molar percentage of the i-th component in natural gas, It is the enthalpy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment under ideal gas state.

[0116] in,

[0117] T is the natural gas temperature at the inlet or outlet of the residual pressure power generation equipment, A i , B i , C i , D i 、E i and F i are the coefficients of the thermodynamic equation of the i-th component in natural gas under the ideal gas state. The specific values ​​can be based on Figure 6 Obtained by reading the diagram.

[0118] S304: Calculate the enthalpy of the natural gas at the inlet and the outlet of the residual pressure power generation equipment according to the influence of the pressure on the enthalpy of the natural gas and the enthalpy of the natural gas at the inlet and the outlet under an ideal gas state.

[0119] Specifically, the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment are calculated by the following formula:

[0120]

[0121] Among them, H m The enthalpy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment, is the enthalpy of the natural gas at the inlet or outlet of the residual pressure power generation equipment under ideal gas state. In formula (7), (H 0 -H) m As a whole, it can be obtained according to formula (3). Both sides of formula (3) are multiplied by RT c , we can get (H 0 -H) m The value of .

[0122] In the embodiments of this specification, refer to Fig. 9 , the step of calculating the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operating data further includes:

[0123] S401: According to the comparative temperature and comparative pressure of the natural gas, read the graph to obtain the influence of pressure on the entropy value of the simple fluid, and the influence deviation of pressure on the entropy values ​​of the real fluid and the simple fluid;

[0124] Reference Figure 7 and Figure 8 , Figure 7 The effect of pressure on the entropy of a simple fluid is shown. Figure 8 The figure shows the effect of pressure on the entropy of real fluid and simple fluid. After knowing the comparative temperature and comparative pressure of natural gas, the comprehensive comparative temperature T rand the contrast pressure P r , by reading Figure 7 , the vertical coordinate value obtained The effect of pressure on the entropy of a simple fluid, compared with temperature T r and the contrast pressure P r , by reading Figure 8 , the vertical coordinate value obtained is the deviation of the effect of pressure on the entropy value of real fluid and simple fluid.

[0125] S402: Calculate the influence of pressure on the entropy value of natural gas according to the influence of pressure on the entropy value of simple fluid and the influence deviation of pressure on the entropy values ​​of real fluid and simple fluid;

[0126] The effect of pressure on the entropy value of natural gas is calculated by the following formula:

[0127]

[0128] in, is the effect of pressure on the entropy of natural gas, is the effect of pressure on the entropy of a simple fluid, is the deviation of the effect of pressure on the entropy of real fluid and simple fluid, ω m is the eccentricity factor of natural gas, R is the gas constant, R = 8.3145 kJ / (kmol·K).

[0129] Specific:

[0130] ω m =∑y i ω i (9)

[0131] Among them, y i is the molar percentage of the i-th component in natural gas, ω i is the eccentricity factor of the i-th component in natural gas, with a dimension of 1.

[0132] S403: Calculating the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under the ideal gas state according to the entropy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under the ideal gas state;

[0133] Specifically, the entropy values ​​of the natural gas at the inlet and outlet of the residual pressure power generation equipment under the ideal gas state are calculated by the following formula:

[0134]

[0135] in, is the entropy value of the i-th component in natural gas under ideal gas state, y iis the molar percentage of the i-th component in natural gas, It is the entropy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment under the ideal gas state.

[0136] in,

[0137] T is the natural gas temperature at the inlet or outlet of the residual pressure power generation equipment, B i , C i , D i 、E i 、F i and G i are the coefficients of the thermodynamic equation of the i-th component in natural gas under the ideal gas state. The specific values ​​can be based on Figure 6 Obtained by reading the diagram.

[0138] S404: According to the influence of the pressure on the entropy value of the natural gas and the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet under an ideal gas state, the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment are calculated.

[0139] Specifically, the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment are calculated by the following formula:

[0140]

[0141] Among them, S m The entropy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment, is the entropy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment under the ideal gas state. In formula (12), (S 0 -S) m As a whole, it can be obtained according to formula (8). Multiplying both sides of formula (8) by R, we can get (S 0 -S) m The value of .

[0142] In an embodiment of the present specification, the step of calculating the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment, and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment further includes:

[0143] The ideal work of the residual pressure power generation equipment is calculated by the following formula:

[0144] W d =(H2-H1)-T0(S2-S1)(13)

[0145] Among them, Wd is the ideal work of the residual pressure power generation equipment, H2 is the enthalpy of natural gas at the outlet of the residual pressure power generation equipment, H1 is the enthalpy of natural gas at the inlet of the residual pressure power generation equipment, S2 is the entropy of natural gas at the outlet of the residual pressure power generation equipment, S1 is the entropy of natural gas at the inlet of the residual pressure power generation equipment, and T0 is the ground state temperature.

[0146] Furthermore, according to the ideal work, the efficiency of the residual pressure power generation equipment can be calculated by the following formula:

[0147]

[0148] Where η is the efficiency of the residual pressure power generation equipment, W is the power generation of the residual pressure power generation equipment, and W d is the ideal work of the residual pressure power generation equipment, and Q is the natural gas flow rate.

[0149] The power generation and natural gas flow of the residual pressure power generation equipment are obtained through the operation data obtained in S101, and the power generation and natural gas flow of the residual pressure power generation equipment are accumulated values ​​obtained multiple times.

[0150] Based on the above-mentioned method for calculating the efficiency of a natural gas excess pressure power generation equipment, an embodiment of this specification also provides a corresponding device for calculating the efficiency of a natural gas excess pressure power generation equipment. The device may include a system (including a distributed system), software (application), module, component, server, client, etc. using the method described in the embodiment of this specification and a device combined with necessary implementation hardware. Based on the same innovative concept, the device in one or more embodiments provided in the embodiment of this specification is as described in the following embodiments. Since the implementation scheme and method of the device to solve the problem are similar, the implementation of the specific device in the embodiment of this specification can refer to the implementation of the aforementioned method, and the repetitions will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0151] Specifically, Fig.10 This is a schematic diagram of a module structure of an embodiment of a device for calculating the efficiency of a natural gas residual pressure power generation device provided in the embodiment of this specification, referring to Fig.10 As shown, an efficiency calculation device for a natural gas excess pressure power generation equipment provided in an embodiment of the present specification includes: an acquisition module 100, an enthalpy value calculation module 200, an entropy value calculation module 300, an ideal work calculation module 400, and an efficiency calculation module 500.

[0152] An acquisition module 100 is used to acquire operation data of the residual pressure power generation equipment;

[0153] An enthalpy value calculation module 200 is used to calculate the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data;

[0154] An entropy value calculation module 300, used to calculate the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data;

[0155] The ideal work calculation module 400 is used to calculate the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment, and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment;

[0156] The efficiency calculation module 500 is used to calculate the efficiency of the residual pressure power generation equipment according to the ideal work.

[0157] Reference Fig.11 As shown, based on the above-mentioned method for calculating the efficiency of a natural gas residual pressure power generation device, a computer device 1102 is also provided in an embodiment of this specification, wherein the above-mentioned method is run on the computer device 1102. The computer device 1102 may include one or more processors 1104, such as one or more central processing units (CPUs) or graphics processing units (GPUs), and each processing unit may implement one or more hardware threads. The computer device 1102 may also include any memory 1106, which is used to store any kind of information such as code, settings, data, etc. In a specific embodiment, the computer program on the memory 1106 and which can be run on the processor 1104, when the computer program is run by the processor 1104, can execute instructions according to the above-mentioned method. Non-limitingly, for example, the memory 1106 may include any one or more combinations of the following: any type of RAM, any type of ROM, flash memory device, hard disk, optical disk, etc. More generally, any memory may use any technology to store information. Further, any memory may provide volatile or non-volatile retention of information. Further, any memory may represent a fixed or removable component of the computer device 1102. In one embodiment, when the processor 1104 executes the associated instructions stored in any memory or combination of memories, the computer device 1102 can perform any operation of the associated instructions. The computer device 1102 also includes one or more drive mechanisms 1108 for interacting with any memory, such as a hard disk drive mechanism, an optical disk drive mechanism, etc.

[0158] The computer device 1102 may also include an input / output module 1110 (I / O) for receiving various inputs (via input devices 1112) and for providing various outputs (via output devices 1114). A specific output mechanism may include a presentation device 1116 and an associated graphical user interface 1118 (GUI). In other embodiments, the input / output module 1110 (I / O), input device 1112, and output device 1114 may not be included, and the computer device 1102 may be used as a computer device in a network. The computer device 1102 may also include one or more network interfaces 1120 for exchanging data with other devices via one or more communication links 1122. One or more communication buses 1124 couple the components described above together.

[0159] The communication link 1122 may be implemented in any manner, for example, through a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication link 1122 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc. governed by any protocol or combination of protocols.

[0160] Corresponds to Figure 1 , Figure 2 , Figure 5 and Fig. 9 The method in the embodiment of the present specification also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are executed.

[0161] The embodiment of the present specification also provides a computer-readable instruction, wherein when the processor executes the instruction, the program therein causes the processor to execute the following Figure 1 , Figure 2 , Figure 5 and Fig. 9 The method shown.

[0162] It should be understood that in the various embodiments of this specification, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this specification.

[0163] It should also be understood that in the embodiments of this specification, the term "and / or" is only a description of the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the embodiments of this specification generally indicates that the associated objects before and after are in an "or" relationship.

[0164] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the embodiments of this specification can be implemented with electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the embodiments of this specification.

[0165] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0166] In the several embodiments provided in this specification, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or it can be an electrical, mechanical or other form of connection.

[0167] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of this specification.

[0168] In addition, each functional unit in each embodiment of this specification may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0169] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of this specification is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of this specification. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

[0170] Specific embodiments are used in this specification to illustrate the principles and implementation methods of the embodiments of this specification. The description of the above embodiments is only used to help understand the methods and core ideas of the embodiments of this specification. At the same time, for those skilled in the art, according to the ideas of the embodiments of this specification, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the embodiments of this specification.

Claims

1. A method for calculating the efficiency of a natural gas residual pressure power generation equipment, characterized in that: include: Obtaining the operating data of the residual pressure power generation equipment; Calculating the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data; Calculating the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data; Calculating the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment, and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment; The efficiency of the residual pressure power generation equipment is calculated according to the ideal work.

2. The efficiency calculation method of natural gas residual pressure power generation equipment according to claim 1 is characterized in that: After obtaining the operation data of the residual pressure power generation equipment, the method further includes: Calculating the critical temperature and critical pressure of the natural gas according to the critical temperatures and critical pressures of different components in the natural gas; The relative temperature and relative pressure of the natural gas are calculated according to the critical temperature and the critical pressure.

3. The efficiency calculation method of natural gas residual pressure power generation equipment according to claim 2 is characterized in that: Calculating the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data further includes: According to the comparative temperature and comparative pressure of the natural gas, the influence of pressure on the enthalpy of simple fluid and the deviation of the influence of pressure on the enthalpy of real fluid and simple fluid are obtained by reading the graph; The influence of pressure on the enthalpy of natural gas is calculated based on the influence of pressure on the enthalpy of simple fluid and the deviation of the influence of pressure on the enthalpy of real fluid and simple fluid; Calculating the enthalpy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under the ideal gas state according to the enthalpy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under the ideal gas state; According to the influence of the pressure on the enthalpy of natural gas and the enthalpy of the natural gas at the inlet and the natural gas at the outlet under ideal gas state, the enthalpy of the natural gas at the inlet and the enthalpy of the natural gas at the outlet of the residual pressure power generation equipment are calculated.

4. The efficiency calculation method of natural gas residual pressure power generation equipment according to claim 3 is characterized in that: The step of calculating the enthalpy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under the ideal gas state according to the enthalpy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under the ideal gas state further comprises: The enthalpy values ​​of the natural gas at the inlet and outlet of the residual pressure power generation equipment under the ideal gas state are calculated by the following formula: in, is the enthalpy of the i-th component in natural gas under ideal gas state, y i is the molar percentage of the i-th component in natural gas, It is the enthalpy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment under ideal gas state.

5. The efficiency calculation method of natural gas residual pressure power generation equipment according to claim 2 is characterized in that: Calculating the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data further includes: According to the comparative temperature and comparative pressure of the natural gas, the influence of pressure on the entropy value of the simple fluid and the deviation of the influence of pressure on the entropy values ​​of the real fluid and the simple fluid are obtained by reading the graph; The influence of pressure on the entropy value of natural gas is calculated based on the influence of pressure on the entropy value of simple fluid and the deviation of the influence of pressure on the entropy values ​​of real fluid and simple fluid; Calculating the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under the ideal gas state according to the entropy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under the ideal gas state; According to the influence of the pressure on the entropy value of natural gas and the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet under ideal gas state, the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment are calculated.

6. The efficiency calculation method of natural gas residual pressure power generation equipment according to claim 5 is characterized in that: The step of calculating the entropy values ​​of the natural gas at the inlet and the natural gas at the outlet of the residual pressure power generation equipment under the ideal gas state according to the entropy values ​​of different components in the natural gas at the inlet and the natural gas at the outlet under the ideal gas state further comprises: The entropy values ​​of the natural gas at the inlet and outlet of the residual pressure power generation equipment under the ideal gas state are calculated by the following formula: in, is the entropy value of the i-th component in natural gas under ideal gas state, y i is the molar percentage of the i-th component in natural gas, It is the entropy value of the natural gas at the inlet or outlet of the residual pressure power generation equipment under the ideal gas state.

7. The efficiency calculation method of natural gas residual pressure power generation equipment according to claim 1, characterized in that: The calculating the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment further comprises: The ideal work of the residual pressure power generation equipment is calculated by the following formula: <h2 style=";text-align:left;direction:ltr">W<h2 style=";text-align:left;direction:ltr"> d <h2 style=";text-align:left;direction:ltr"> (H2-H1)-T0(S2-S1) Among them, W d is the ideal work of the residual pressure power generation equipment, H2 is the enthalpy of natural gas at the outlet of the residual pressure power generation equipment, H1 is the enthalpy of natural gas at the inlet of the residual pressure power generation equipment, S2 is the entropy of natural gas at the outlet of the residual pressure power generation equipment, S1 is the entropy of natural gas at the inlet of the residual pressure power generation equipment, and T0 is the ground state temperature.

8. An efficiency calculation device for a natural gas residual pressure power generation equipment, characterized in that: The device comprises: An acquisition module, used to acquire operation data of the residual pressure power generation equipment; An enthalpy value calculation module, used to calculate the enthalpy value of the natural gas at the inlet and the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data; An entropy value calculation module, used to calculate the entropy value of the natural gas at the inlet and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment according to the operation data; an ideal work calculation module, used to calculate the ideal work of the residual pressure power generation equipment according to the enthalpy value of the natural gas at the inlet of the residual pressure power generation equipment, the enthalpy value of the natural gas at the outlet of the residual pressure power generation equipment, the entropy value of the natural gas at the inlet of the residual pressure power generation equipment, and the entropy value of the natural gas at the outlet of the residual pressure power generation equipment; The efficiency calculation module is used to calculate the efficiency of the residual pressure power generation equipment according to the ideal work.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory, characterized in that: When the computer program is executed by the processor, the computer program executes the instructions of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor of a computer device, the computer program executes instructions of the method according to any one of claims 1 to 7.

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