Evolutionary game and system dynamics-based development method of green methanol for shipping

Abstract

The invention provides a green methanol development method for shipping based on evolutionary game and system dynamics, which comprises the following steps: taking a government, a port enterprise and a shipping company in the development process of green methanol for shipping as main bodies, and respectively analyzing strategic choices; constructing an evolutionary game model according to strategic selection; establishing a revenue matrix according to the evolutionary game model; analyzing the stability of a system balance point in the evolutionary game model, and analyzing the development process of green methanol according to a life cycle theory; a three-party evolutionary game dynamics model is constructed, and research on the development process of the green methanol for shipping is achieved. According to the method, the evolutionary game theory and the system dynamics theory are combined, the green methanol ship promotion policy is deeply analyzed, and through unique parameter design and balance point selection, an actual enlightenment and an effective policy for promoting green methanol development are provided for policy formulation.

Description

Technical Field

[0001] The present invention relates to the field of clean energy, and particularly to a development method of green methanol for shipping based on evolutionary game and system dynamics. Background Art

[0002] As an energy-saving mode of commodity transportation, maritime transportation undertakes about 90% of the world's trade volume, ranks at the forefront of the global trade market, and is a barometer of the international economy. The International Maritime Organization is committed to promoting the shipping industry to reduce carbon dioxide emissions to half of those in 2008 by 2050. However, it is estimated that the emissions of the shipping industry will reach 2.5 - 3.65 billion tons by 2050, which may pose a serious threat to climate goals. The introduction of green methanol is a key environmental protection innovation in this process.

[0003] Therefore, studying the development process of green methanol in shipping can provide inspiration for policy-making and port enterprise decision-making. Summary of the Invention

[0004] In view of the above-mentioned technical problems, a development method of green methanol for shipping based on evolutionary game and system dynamics is provided. The present invention mainly uses the decision-making behaviors and interaction mechanisms of the government, port enterprises, and shipping companies for the development of green methanol, establishes a tripartite evolutionary game model, and derives the evolutionary stable strategy and its corresponding conditions. Through numerical simulation, the dynamic evolution process of the strategic choices of stakeholders in different scenarios and their sensitivity to key parameters are analyzed. Finally, targeted suggestions are put forward based on the obtained results.

[0005] The technical means adopted by the present invention are as follows:

[0006] A development method of green methanol for shipping based on evolutionary game and system dynamics, comprising:

[0007] Regarding the government, port enterprises, and shipping companies in the development process of green methanol for shipping as the main bodies, and respectively analyzing their strategic choices;

[0008] Constructing an evolutionary game model according to the strategic choices;

[0009] Establishing a payoff matrix according to the evolutionary game model;

[0010] Analyzing the stability of the system equilibrium point in the evolutionary game model, and analyzing the development process of green methanol according to the life cycle theory;

[0011] Constructing a tripartite evolutionary game dynamics model to realize the research on the development process of green methanol for shipping.

[0012] Furthermore, the analysis of the strategic choices specifically includes:

[0013] The set of strategic choices of the government is represented as: G = (G1, G2), where promoting is G1 and not promoting is G2. The set of strategic choices of port enterprises is represented as: P = (P1, P2), where constructing is P1 and not constructing is P2. The set of strategic choices of shipping companies is represented as S = (S1, S2), where renovating is S1 and not renovating is S2;

[0014] In the initial stage, the probabilities of the government choosing to promote or not promote are x and 1 - x respectively, the probabilities of port enterprises choosing to construct or not construct are y and 1 - y respectively, and the probabilities of shipping companies choosing to renovate or not renovate are z and 1 - z respectively.

[0015] Furthermore, constructing the evolutionary game model according to the strategic choices specifically includes:

[0016] The initial social welfare of the government is represented as P g0 , when the government chooses the G1 strategy, the costs of policy implementation, promotion, and supervision are E g1 , the benefits brought to the government after the ships complete the installation of green methanol are P g1 ; the benefits brought to the government after port enterprises complete the installation of green methanol are P g3 ; when the government chooses the G1 strategy and the port enterprise chooses the P1 strategy, the cost for the government to check whether the port enterprise has fraudulently obtained subsidies is E g2 , the port enterprise has a probability of μ p of implementing fraudulent subsidy behavior. If there is fraudulent subsidy, the government will definitely detect it and impose a penalty on the enterprise. The fraudulent subsidy penalty amount is U p ; when the government chooses the G1 strategy and the shipping company chooses the S1 strategy, the cost for the government to check whether the shipping company has fraudulently obtained subsidies is E g3 , the shipping company has a probability of μ s of implementing fraudulent subsidy behavior. If there is fraudulent subsidy, the government will definitely detect it and impose a penalty on the company. The fraudulent subsidy penalty amount is U s ; when the government chooses the G2 strategy, the benefits brought to the government by port enterprises after the ships complete the installation of green methanol are P g2 , the benefits brought to the government by shipping companies after the ships complete the installation of green methanol are P g4; When the government chooses strategy G1 and the port enterprise chooses strategy P1, the government conducts the acceptance inspection work of green methanol for the port enterprise and rewards and subsidizes the construction work of the port enterprise. The government's reward coefficient for the port enterprise to build green methanol facilities is ω1; the government provides an operation subsidy to the port that uses green methanol receiving facilities as required, and the subsidy coefficient is ω2; when the government chooses strategy G1 and the shipping company chooses strategy S1, for each ship the shipping company retrofits, the government's subsidy coefficient for the shipping company is ω3; when the government chooses strategy G1, the port enterprise chooses strategy P2, and the shipping company chooses strategy S2, the government will supervise the port enterprise and the shipping company, and the penalty cost for the port enterprise to resist the construction of green methanol facilities is E p2 , and the penalty cost for the shipping company to resist the construction of green methanol facilities is E s3 ;

[0017] Denote the initial income of the port enterprise as P p0 , E p1 is the construction cost of the green methanol facility, and the expenditure of the port to purchase green methanol is F p , when the government chooses strategy G1 and the port enterprise chooses strategy P1, the construction subsidy and operation subsidy obtained by the port enterprise from the government are ω1E p1 and ω2F p ; When the local government does not have a green methanol promotion policy, the port enterprise will suffer losses in other aspects such as competition, which is E p3 ; When the government implements the policy, the port enterprise gives a subsidy E to the shipping company that refuels with green methanol ps , when the port enterprise chooses strategy P1 and the shipping company chooses strategy S2, under the premise of maximizing its own interests, the port enterprise will not choose to purchase green methanol.

[0018] Denote the initial income of the shipping company as P s0 , when the shipping company chooses strategy S1, the increased income brought to the shipping company by using green methanol is P s1 , the cost of retrofitting the green methanol receiving equipment for the ship is E s1 , the berthing cost generated by the ship during its stay in the port is E s2 ; When the government does not have relevant policies on green methanol, the shipping company will suffer losses in competition, which is E s4 ; When the government chooses strategy G1 and the shipping company chooses strategy S1, the cost for the ship to obtain green methanol under the preferential policy is F s1 , and the subsidy amount for the shipping company is ω3E s1 ; When the government chooses strategy G2 and the shipping company chooses strategy S1, the cost for the ship to purchase green methanol is F s2 , and the cost of the ship using traditional fuel is F s .

[0019] Furthermore, establishing the payoff matrix according to the evolutionary game model specifically includes:

[0020] When the strategic choice of the government is to promote G1, the strategic choice of the port enterprise is to construct P1, and the strategic choice of the shipping company is to transform S1, the payoffs of the three parties are respectively:

[0021] Government payoff:

[0022] P g0 +P g1 +P g3 -E g1 -E g2 -E g3 -ω1E p1 -ω2F p -ω3E s1 +μ p U p +μ s U s

[0023] Port enterprise payoff: P p0 +P p1 +ω1E p1 +ω2E p -E p1 -E ps -F p -μ p U p

[0024] Shipping company payoff: P s0 +P s1 +ω3E s1 -E s1 -E s2 +E ps -F s1 -F s -μ s U s ;

[0025] When the strategic choice of the government is to promote G1, the strategic choice of the port enterprise is to construct P1, and the strategic choice of the shipping company is not to transform S2, the payoffs of the three parties are respectively:

[0026] Government payoff: P g0 +P g1 -E g1 -E g2 -ω1E p1 +E s3 +μ p U p

[0027] Port enterprise revenue: P p0 +ω1E p1 -E p1 -μ p U p

[0028] Shipping company revenue: P s0 -E s2 -E s3 -F s ;

[0029] When the government's strategic choice is to promote G1, the port enterprise's strategic choice is not to build P2, and the shipping company's strategic choice is to transform S1, the revenues of the three parties are respectively:

[0030] Government revenue: P g0 +P g3 +E p2 -E g1 -E g3 -ω3E s1 +μ s U s

[0031] Port enterprise revenue: P p0 -E p2

[0032] Shipping company revenue: P s0 +P s1 +ω3E s1 -E s1 -E s2 -F s1 -F s -μ s U s ;

[0033] When the government's strategic choice is to promote G1, the port enterprise's strategic choice is not to build P2, and the shipping company's strategic choice is not to transform S2, the revenues of the three parties are respectively:

[0034] Government revenue: P g0 -E g1 +E s3 +E p2

[0035] Port enterprise revenue: P p0 -E p2

[0036] Shipping company revenue: P s0 -E s2 -E s3 -F s ;

[0037] When the government's strategic choice is not to promote G2, the port enterprise's strategic choice is to build P1, and the shipping company's strategic choice is to transform S1, the benefits of the three parties are as follows:

[0038] Government benefit: P g0 +P g2 +P g4

[0039] Port enterprise benefit: P p0 +P p1 -E p1 -E p3 -F p

[0040] Shipping company benefit: P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s ;

[0041] When the government's strategic choice is not to promote G2, the port enterprise's strategic choice is to build P1, and the shipping company's strategic choice is not to transform S2, the benefits of the three parties are as follows:

[0042] Government benefit: P g0 +P g4

[0043] Port enterprise benefit: P p0 -E p1 -E p3

[0044] Shipping company benefit: P s0 -E s2 -E s4 -F s

[0045] When the government's strategic choice is not to promote G2, the port enterprise's strategic choice is not to build P2, and the shipping company's strategic choice is to transform S1, the benefits of the three parties are as follows:

[0046] Government benefit: P g0 +P g2

[0047] Port enterprise benefit: P p0 -E p3

[0048] Shipping company benefit: P s0 +P s1 -E s1 -E s2 -E s4 -Fs2 -F s

[0049] When the government's strategic choice is not to promote G2, the port enterprise's strategic choice is not to build P2, and the shipping company's strategic choice is not to transform S2, the benefits of the three parties are as follows:

[0050] Government benefit: P g0

[0051] Port enterprise benefit: P p0 -E p3

[0052] Shipping company benefit: P s0 -E s2 -E s4 -F s 。

[0053] Furthermore, analyze the stability of the system equilibrium point in the evolutionary game model, and analyze the development process of green methanol according to the life cycle theory, specifically including:

[0054] The Jacobian matrix of the three-party evolutionary game among the government, port enterprises, and shipping companies is:

[0055]

[0056] According to Lyapunov's first law: If all the eigenvalues of the Jacobian matrix have negative real parts, then this equilibrium point is an asymptotically stable point; if one of the eigenvalues of the Jacobian matrix has a positive real part, then this equilibrium point is an unstable point;

[0057] Divide the development of green methanol into the initial stage, growth stage, and mature stage according to the life cycle theory; in the initial stage, the government's strategic choice is to promote, port enterprises build green methanol receiving facilities, and shipping companies have a negative attitude towards transforming green methanol facilities; in the growth stage, the government's strategic choice is to promote, port enterprises build green methanol receiving facilities, and shipping companies have a positive attitude towards green methanol facilities; in the mature stage, the willingness of port enterprises and shipping companies to participate in green methanol construction work increases, and no government intervention is required.

[0058] Furthermore, the construction of the three-party evolutionary game dynamics model specifically includes:

[0059] Express the expected benefits of the government's strategic choices of promoting and not promoting as E 11 、E 12 , and the average benefit is Then:

[0060] E 11 =yz(P g0+P g1 +P g3 -E g1 -Eg2-E g3 -ω1E p1 -ω2F p -ω3E s1 +μ p U p +μ s U s )+y(1 - z)(P g0 +P g1 -E g1 -E g2 -ω1E p1 +E s3 +μ p U p )+(1 - y)z(P g0 +P g3 +E p2 -E g1 -E g3 -ω3E s1 +μ s U s )+(1 - y)(1 - z)(P g0 -E g1 +E s3 +E p2 )

[0061] E 12 =yz(P g0 +P g2 +P g4 )+y(1 - z)(P g0 +P g4 )+(1 - y)z(P g0 +P g2 )+(1 - y)(1 - z)P g0

[0062]

[0063] The replicator dynamic equation of the government is:

[0064]

[0065] Express the expected returns of the port enterprise's strategic choices of construction and non - construction as E 21 、E 22 , and the average return is Then:

[0066] E 21 =xz(P p0 +P p1 +ω1E p1+ω2F p -E p1 -E ps -F p -μ p U p )+x(1 - z)(P p0 +ω1E p1 -E p1 -μ p U p )+(1 - x)z(P p0 +P p1 -E p1 -E p3 -F p )+(1 - x)(1 - z)(P p0 -E p1 -E p3 )

[0067] E 22 =xz(P p0 -E p2 )+x(1 - z)(P p0 -E p2 )+(1 - x)z(P p0 -E p3 )+(1 - x)(1 - z)(P p0 -E p3 )

[0068]

[0069] The replicator dynamic equation of port enterprises is:

[0070]

[0071] Express the expected returns of the shipping company's strategic choices of transformation and non - transformation as E 31 、E 32 , and the average return is Then:

[0072] E 31 =xy(P s0 +P s1 +ω3E s1 -E s1 -E s2 +E ps -F s1 -F s -μ s U s )+x(1 - y)(P s0 +P s1 +ω3E s1 -E s1 -Es2 -F s1 -F s -μ s U s )+(1 - x)y(P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s )+(1 - x)(1 - y)(P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s )

[0073] E 32 =xy(P s0 -E s2 -E s3 -F s )+x(1 - y)(P s0 -E s2 -E s3 -F s )+(1 - x)y(P s0 -E s2 -E s4 -F s )+(1 - x)(1 - y)(P s0 -E s2 -E s4 -F s )

[0074]

[0075] The shipping company's copy of the state equation is:

[0076]

[0077] Compared with the prior art, the present invention has the following advantages:

[0078] The green methanol development method for shipping based on evolutionary game and system dynamics provided by the present invention uses evolutionary game to analyze the decision-making behaviors and interaction mechanisms of the government, port enterprises, and shipping companies regarding the development of green methanol, establishes a tripartite evolutionary game model, and derives the evolutionary stable strategies and their corresponding conditions. Through numerical simulation, the dynamic evolutionary process of the strategic choices of stakeholders in different scenarios and their sensitivity to key parameters are analyzed. The results show that the government plays a leading role in the process of green methanol development and plays different roles in different stages of green methanol development; the reasonable setting of green methanol costs is crucial for promoting its application and transformation in the shipping industry. The government's punishment intensity for fraud in subsidies to shipping companies should be dynamically adjusted according to the market development stage. In the initial stage of promoting green methanol policies, the government should control costs and increase incentives to promote market acceptance and participation, while in the mature stage, it can appropriately increase costs to promote market self-regulation.

[0079] By combining evolutionary game theory with system dynamics theory, the present invention innovatively constructs a comprehensive dynamic decision-making model, deeply analyzes the green methanol ship promotion policy, and provides practical inspirations and effective strategies for promoting the development of green methanol through unique parameter design and equilibrium point selection. The insights and models of the present invention are not only applicable to green methanol, but also provide a theoretical framework for the development of other new energy sources, which is conducive to achieving the carbon emission reduction goal as soon as possible.

[0080] For the above reasons, the present invention can be widely promoted in the fields of clean energy and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0082] Figure 1 It is a flow chart of the green methanol development method for shipping based on evolutionary game and system dynamics in the present invention.

[0083] Figure 2 It is a graph of the evolutionary trend of the government's behavior in the embodiment of the present invention.

[0084] Figure 3 It is a graph of the evolutionary trend of the port enterprise's behavior in the embodiment of the present invention.

[0085] Figure 4 It is a graph of the evolutionary trend of the shipping company's behavior in the embodiment of the present invention.

[0086] Figure 5It is the diagram of the balance point (1, 1, 0) in the embodiments of the present invention.

[0087] Figure 6 It is the diagram of the balance point (1, 1, 1) in the embodiments of the present invention.

[0088] Figure 7 It is the diagram of the balance point (0, 1, 1) in the embodiments of the present invention.

[0089] Figure 8 It is the influence diagram of Fs1 in the embodiments of the present invention.

[0090] Figure 9 It is the influence diagram of Us in the embodiments of the present invention.

[0091] Figure 10 It is the influence diagram of Eg1 in the embodiments of the present invention. Detailed implementation manners

[0092] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0093] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way restricts the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0094] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0095] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0096] As Figure 1 shown, the present invention provides a method for the development of green methanol for shipping based on evolutionary game and system dynamics, characterized by comprising:

[0097] Regarding the government, port enterprises, and shipping companies in the process of the development of green methanol for shipping as the main bodies, respectively analyze the strategic choices;

[0098] When specifically implemented, as a preferred embodiment of the present invention, the analysis of strategic choices specifically includes:

[0099] Represent the strategic choice set of the government as: G = (G1, G2), where promotion is G1 and non - promotion is G2; represent the strategic choice set of port enterprises as: P = (P1, P2), where construction is P1 and non - construction is P2; represent the strategic choice set of shipping companies as S = (S1, S2), where retrofit is S1 and non - retrofit is S2; the stakeholders select a probabilistic option from their respective choice sets.

[0100] In the initial stage, the probabilities of the government choosing promotion or non - promotion are x and 1 - x respectively, the probabilities of port enterprises choosing construction or non - construction are y and 1 - y respectively, and the probabilities of shipping companies choosing retrofit or non - retrofit are z and 1 - z respectively. If a port enterprise completes the construction of green methanol, it must purchase green methanol for storage. The retrofitted ships can use dual - fuel, that is, they can use either traditional fuel or green methanol.

[0101] Construct an evolutionary game model according to the strategic choices;

[0102] When specifically implemented, as a preferred embodiment of the present invention, the construction of the evolutionary game model according to the strategic choices specifically includes:

[0103] Represent the initial social welfare of the government as P g0, when the government chooses the G1 strategy, the costs of policy implementation, promotion, and supervision are E g1 , the benefit brought to the government by the ship after completing the green methanol installation is P g1 ; the benefit brought to the government by the port enterprise after completing the green methanol installation is P g3 ; when the government chooses the G1 strategy and the port enterprise chooses the P1 strategy, the cost for the government to inspect whether the port enterprise has fraudulently claimed subsidies is E g2 , the port enterprise has a probability of μ p of implementing fraudulent subsidy claims. If there is fraud, the government will definitely detect it and impose a penalty on the enterprise. The penalty amount for fraudulent subsidy claims is U p ; when the government chooses the G1 strategy and the shipping company chooses the S1 strategy, the cost for the government to inspect whether the shipping company has fraudulently claimed subsidies is E g3 , the shipping company has a probability of μ s of implementing fraudulent subsidy claims. If there is fraud, the government will definitely detect it and impose a penalty on the company. The penalty amount for fraudulent subsidy claims is U s ; when the government chooses the G2 strategy, the benefit brought to the government by the port enterprise after the ship completes the green methanol installation is P g2 , the benefit brought to the government by the shipping company after the ship completes the green methanol installation is P g4 ; when the government chooses the G1 strategy and the port enterprise chooses the P1 strategy, the government conducts the completion acceptance work of green methanol for the port enterprise and provides reward subsidies for the construction work of the port enterprise. The reward coefficient of the government for the port enterprise to build green methanol facilities is ω1; the government provides operation subsidies for the ports that complete the use of green methanol receiving facilities as required, and the subsidy coefficient is ω2; when the government chooses the G1 strategy and the shipping company chooses the S1 strategy, for each ship renovated by the shipping company, the subsidy coefficient of the government for the shipping company is ω3; the construction and renovation subsidies for both the port enterprise and the shipping company are awarded by the government in a 1:1 ratio according to the construction or renovation costs. When the government chooses the G1 strategy, the port enterprise chooses the P2 strategy, and the shipping company chooses the S2 strategy, the government will supervise the port enterprise and the shipping company, and the penalty cost for the port enterprise to resist the construction of green methanol facilities is E p2 , the penalty cost for the shipping company to resist the construction of green methanol facilities is E s3 ;

[0104] Denote the initial income of the port enterprise as P p0 , E p1 is the construction cost of the green methanol facility, and the expenditure of the port for purchasing green methanol is F p , when the government chooses the G1 strategy and the port enterprise chooses the P1 strategy, the construction subsidy and operation subsidy obtained by the port enterprise from the government are ω1E p1 and ω2E p; When there is no green methanol promotion policy by the local government, the port enterprise will suffer losses in other aspects such as competition, with the loss being E p3 ; When the government promotes the policy, in order to accelerate the transformation of green methanol facilities, and at the same time each enterprise aims to attract ships that have been retrofitted with green methanol, the port enterprise gives a subsidy E to the shipping company that refuels with green methanol ps , when the port enterprise selects strategy P1 and the shipping company selects strategy S2, on the premise of maximizing its own interests, the port enterprise will not choose to purchase green methanol.

[0105] Express the initial revenue of the shipping company as P s0 , when the shipping company selects strategy S1, the increased revenue brought to the shipping company by using green methanol is P s1 , the cost for the ship to retrofit the green methanol receiving equipment is E s1 , the berthing cost generated by the ship during its stay in the port is E s2 ; When there is no green methanol-related policy by the government, the shipping company will suffer losses in competition, with the loss being E s4 ; When the government selects strategy G1 and the shipping company selects strategy S1, the cost for the ship to obtain green methanol under the preferential policy is F s1 , the subsidy amount for the shipping company is ω3E s1 ; When the government selects strategy G2 and the shipping company selects strategy S1, the cost for the ship to purchase green methanol is F s2 , the cost for the ship to use traditional fuel is F s . Since the ship is a dual-fuel ship, regardless of whether the shipping company chooses to retrofit the green methanol facilities or not, the ship will use traditional fuel.

[0106] Establish a payoff matrix according to the evolutionary game model;

[0107] Specifically in implementation, as a preferred implementation manner of the present invention, the establishment of the payoff matrix according to the evolutionary game model specifically includes:

[0108] When the strategic choice of the government is to promote G1, the strategic choice of the port enterprise is to construct P1, and the strategic choice of the shipping company is to retrofit S1, the payoffs of the three parties are respectively:

[0109] Government payoff:

[0110] P g0 +P g1 +P g3 -E g1 -E g2 -E g3 -ω1E p1 -ω2F p -ω3E s1 +μ p Up +μ s U s

[0111] Port enterprise revenue: P p0 +P p1 +ω1E p1 +ω2F p -E p1 -E ps -F p -μ p U p

[0112] Shipping company revenue: P s0 +P s1 +ω3E s1 -E s1 -E s2 +E ps -F s1 -F s -μ s U s ;

[0113] When the government's strategic choice is to promote G1, the port enterprise's strategic choice is to build P1, and the shipping company's strategic choice is not to transform S2, the benefits of the three parties are respectively:

[0114] Government revenue: P g0 +P g1 -E g1 -E g2 -ω1E p1 +E s3 +μ p U p

[0115] Port enterprise revenue: P p0 +ω1E p1 -E p1 -μ p U p

[0116] Shipping company revenue: P s0 -E s2 -E s3 -F s ;

[0117] When the government's strategic choice is to promote G1, the port enterprise's strategic choice is not to build P2, and the shipping company's strategic choice is to transform S1, the benefits of the three parties are respectively:

[0118] Government revenue: P g0 +P g3 +E p2 -E g1 -Eg3 -ω3E s1 +μ s U s

[0119] Port enterprise revenue: P p0 -E p2

[0120] Shipping company revenue: P s0 +P s1 +ω3E s1 -E s1 -E s2 -F s1 -F s -μ s U s ;

[0121] When the government's strategic choice is to promote G1, the port enterprise's strategic choice is not to build P2, and the shipping company's strategic choice is not to transform S2, the revenues of the three parties are respectively:

[0122] Government revenue: P g0 -E g1 +E s3 +E p2

[0123] Port enterprise revenue: P p0 -E p2

[0124] Shipping company revenue: P s0 -E s2 -E s3 -F s ;

[0125] When the government's strategic choice is not to promote G2, the port enterprise's strategic choice is to build P1, and the shipping company's strategic choice is to transform S1, the revenues of the three parties are respectively:

[0126] Government revenue: P g0 +P g2 +P g4

[0127] Port enterprise revenue: P p0 +P p1 -E p1 -E p3 -F p

[0128] Shipping company revenue: P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -Fs ;

[0129] When the government's strategic choice is not to promote G2, the port enterprise's strategic choice is to build P1, and the shipping company's strategic choice is not to transform S2, the benefits of the three parties are as follows:

[0130] Government benefit: P g0 +P g4

[0131] Port enterprise benefit: P p0 -E p1 -E p3

[0132] Shipping company benefit: P s0 -E s2 -E s4 -F s

[0133] When the government's strategic choice is not to promote G2, the port enterprise's strategic choice is not to build P2, and the shipping company's strategic choice is to transform S1, the benefits of the three parties are as follows:

[0134] Government benefit: P g0 +P g2

[0135] Port enterprise benefit: P p0 -E p3

[0136] Shipping company benefit: P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s

[0137] When the government's strategic choice is not to promote G2, the port enterprise's strategic choice is not to build P2, and the shipping company's strategic choice is not to transform S2, the benefits of the three parties are as follows:

[0138] Government benefit: P g0

[0139] Port enterprise benefit: P p0 -E p3

[0140] Shipping company benefit: P s0 -E s2 -E s4 -F s 。

[0141] Analyze the stability of the system equilibrium point in the evolutionary game model, and analyze the development process of green methanol according to the life cycle theory;

[0142] When specifically implemented, as a preferred implementation manner of the present invention, analyzing the stability of the system equilibrium point in the evolutionary game model and analyzing the development process of green methanol according to the life cycle theory specifically includes:

[0143] From F(x)=0, F(y)=0, F(z)=0, the system equilibrium points can be obtained: O(0,0,0), A(0,0,1), B(0,1,0), C(0,1,1), D(1,0,0), En(1,0,1), F(1,1,0), G(1,1,1). The Jacobian matrix of the three-party evolutionary game of the government, port enterprises and shipping companies is:

[0144]

[0145] In the replication dynamics equations, let F(x)=F(y)=F(z)=0, and 8 equilibrium points of the evolutionary process can be obtained: E1=(0,0,0), E2=(0,0,1), E3=(0,1,0), E4=(0,1,1), E5=(1,0,0), E6=(1,0,1), E7=(1,1,0), E8=(1,1,1).

[0146] According to Lyapunov's first law: if all the eigenvalues of the Jacobian matrix have negative real parts, then this equilibrium point is an asymptotically stable point; if one of the eigenvalues of the Jacobian matrix has a positive real part, then this equilibrium point is an unstable point. The eigenvalues of the 8 equilibrium points are shown in Table 1.

[0147] Table 1 System equilibrium points and their eigenvalues

[0148]

[0149]

[0150] Since the parameters involved in the model are relatively complex, it is necessary to analyze in combination with the actual situation when considering stability. According to the life cycle theory, the development of green methanol is divided into the initial stage, the growth stage and the mature stage.

[0151] In the initial stage, the strategic choice of the government is to promote, port enterprises build green methanol receiving facilities, and shipping companies are negative about transforming green methanol facilities; at this time, it is in the early stage of the development of green methanol, which is more in line with the current development situation of green methanol in China. The government will give priority to encouraging port enterprises to build facilities. Due to problems such as immature technology, shipping companies are in a wait-and-see state. First, analyze the eigenvalue λ1, E g1 +Eg2 +P g4 +ω1E p1 <P g1 +E s3 +μ p U p , indicating that the government's decision to implement the policy is based on the premise that ultimately, under the government's promotion policy, the combined benefits and penalty benefits exceed the implementation costs and incentive costs. Secondly, analyze the eigenvalue λ2, μ p U p +E p1 <ω1E p1 +E p2 , meaning that in the initial stage, if a port enterprise wants to carry out the construction work of green methanol, the basic premise is that the sum of the government's subsidy and the penalty cost for the port enterprise's resistance to construction is greater than the sum of the penalty for fraud and the cost of the port enterprise's construction of green methanol. Finally, analyze the eigenvalue λ3, E ps +P s1 +ω3E s1 +E s3 <F s1 +E s1 +μ s U s , considering the actual situation and the eigenvalue situation, at this time the government gives priority to the construction work of green methanol in port enterprises, and the penalty cost for shipping companies' resistance to construction is relatively small. At this time, due to lack of experience, the cost of shipping companies to transform green methanol receiving facilities is relatively high, the initial improvement benefits are relatively small, and the government will strictly inspect the renovated ships and increase the penalty for fraud to ensure normal operation, resulting in ω3E s1 <μ s U s . This also indicates that when the cost of shipping companies to transform green methanol receiving facilities, purchase green methanol and the penalty cost for fraud is greater than the sum of the government's renovation subsidy, the improvement benefits after transforming green methanol receiving facilities and the subsidy from port enterprises to shipping companies, shipping companies choose not to transform green methanol receiving equipment.

[0152] In the growth stage, the government's strategic choice is to promote, port enterprises build green methanol receiving facilities, and shipping companies have a positive attitude towards green methanol facilities; at this time, the government then promotes the green methanol policy, and port enterprises already have sufficient experience in construction. Port enterprises and shipping companies begin to actively cooperate with the government to promote the development of green methanol. First, analyze the eigenvalue λ1, E g1 +E g2 +E g3 +P g2 +P g4 +ω3E s1 +ω2F p +ω1Ep1 <P g1 +P g3 +μ p U p +μ s U s 。Combined with the actual situation and the eigenvalue situation, at this time, due to the promotion of the green methanol policy, a positive market response has been brought, so that the costs of the government in promoting green methanol and supervising related enterprises have been effectively controlled. And at this time, due to the maturity of technology, the benefits brought by port enterprises and shipping companies using green methanol to the government have increased, and are greater than the benefits brought by port enterprises and shipping companies using green methanol to the government without policies. The eigenvalue shows that when the sum of the benefits brought by port enterprises and shipping companies using green methanol to the government and the fraud subsidy punishment is greater than the sum of the government's promotion policy cost, inspection cost, reward cost and the benefits brought by port enterprises and shipping companies using green methanol to the government without policies, the government will actively promote the development of green methanol. When analyzing the eigenvalue λ2 next, E p1 +E ps +F p +μ p U p <E p2 +P p1 +ω1E p1 +ω2E p ,Combined with the actual situation and the eigenvalue situation, at this time, due to the maturity of the technology for port enterprises to build green methanol facilities in the early stage, the construction cost in the growth stage is less than that in the initial stage. The eigenvalue shows that when the sum of the benefits of port enterprises from ships using green methanol, the penalty cost for port enterprises to resist building green methanol facilities and the government's subsidy to port enterprises is greater than the sum of the construction cost of port enterprises' green methanol facilities, the subsidy from port enterprises to shipping companies and the fraud subsidy punishment, port enterprises will choose to build green methanol facilities. Finally, analyze the eigenvalue λ3, E s1 +F s1 +μ s U s <E ps +E s3 +P s1 +ω3E s1, considering the actual situation and eigenvalue situation, at this time, since the government has begun to focus on the development of green methanol for shipping companies, the cost of green methanol paid by ships under preferential policies is less than the cost of green methanol paid by ships without policies. The eigenvalue indicates that when the sum of the subsidy given by port enterprises to shipping companies, the penalty cost for shipping companies to resist building green methanol facilities, the increased revenue from using green methanol by relevant ships of shipping companies and the government subsidy is greater than the sum of the cost of green methanol paid by ships, the cost of modifying green methanol receiving equipment for relevant ships of shipping companies and the penalty for subsidy fraud, shipping companies will choose to transform green methanol facilities.

[0153] In the mature stage, the willingness of port enterprises and shipping companies to participate in the construction of green methanol increases, and government intervention is not required. At this time, the main force of green methanol application mainly composed of port enterprises and shipping companies has gradually formed. First, analyze the eigenvalue λ1, P g1 +P g3 +μ p U p +μ s U s <E g1 +E g2 +E g3 +P g2 +P g4 +ω1E p1 +ω2F p +ω3E s1 . The eigenvalue indicates that when the sum of the cost, subsidy when the government implements policies and the revenue brought by port enterprises and shipping companies to the government without policies is greater than the sum of the revenue brought by port enterprises and shipping companies to the government with policies and the penalty for subsidy fraud, the government will stop taking the initiative to implement. Secondly, analyze the eigenvalue λ2, E p1 +E p <P p1 . The eigenvalue indicates that when the sum of the construction cost of green methanol facilities of port enterprises and the cost of purchasing green methanol is less than the benefit from ships using green methanol, port enterprises will continue with the construction of green methanol. Finally, analyze the eigenvalue λ3, E s1 +F s2 <P s1 . The eigenvalue indicates that when the increased revenue from using green methanol by relevant ships of shipping companies is greater than the sum of the cost of modifying green methanol receiving equipment for relevant ships of shipping companies and the cost of green methanol paid by ships without policies, shipping companies will continue with the transformation of green methanol facilities.

[0154] Construct a tripartite evolutionary game dynamics model to realize the research on the development process of green methanol for shipping.

[0155] In specific implementation, as a preferred implementation manner of the present invention, the construction of the tripartite evolutionary game dynamics model specifically includes:

[0156] The expected returns of the government's strategic choices of promoting and not promoting are respectively expressed as E 11 、E 12 , and the average return is Then:

[0157] E 11 = yz(P g0 + P g1 + P g3 - E g1 - E g2 - E g3 - ω1E p1 - ω2F p - ω3E s1 + μ p U p + μ s U s ) + y(1 - z)(P g0 + P g1 - E g1 - E g2 - ω1E p1 + E s3 + μ p U p ) + (1 - y)z(P g0 + P g3 + E p2 - E g1 - E g3 - ω3E s1 + μ s U s ) + (1 - y)(1 - z)(P g0 - E g1 + E s3 + E p2 )

[0158] E 12 = yz(P g0 + P g2 + P g4 ) + y(1 - z)(P g0 + P g4 ) + (1 - y)z(P g0 + P g2 ) + (1 - y)(1 - z)P g0

[0159]

[0160] The replication dynamic equation of the government is:

[0161]

[0162] The expected returns of the port enterprise's strategic choices of building and not building are denoted as E 21 and E 22 , and the average return is Then:

[0163] E 21 = xz(P p0 + P p1 + ω1E p1 + ω2F p - E p1 - E ps - F p - μ p U p ) + x(1 - z)(P p0 + ω1E p1 - E p1 - μ p U p ) + (1 - x)z(P p0 + P p1 - E p1 - E p3 - F p ) + (1 - x)(1 - z)(P p0 - E p1 - E p3 )

[0164] E 22 = xz(P p0 - E p2 ) + x(1 - z)(P p0 - E p2 ) + (1 - x)z(P p0 - E p3 ) + (1 - x)(1 - z)(P p0 - E p3 )

[0165]

[0166] The replicator dynamic equation of the port enterprise is:

[0167]

[0168] The expected returns of the shipping company's strategic choices of transformation and non - transformation are denoted as E 31 and E 32 , and the average return is Then:

[0169] E 31 = xy(P s0+P s1 +ω3E s1 -E s1 -E s2 +E ps -F s1 -F s -μ s U s )+x(1 - y)(P s0 +P s1 +ω3E s1 -E s1 -E s2 -F s1 -F s -μ s U s )+(1 - x)y(P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s )+(1 - x)(1 - y)(P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s )

[0170] E 32 =xy(P s0 -E s2 -E s3 -F s )+x(1 - y)(P s0 -E s2 -E s3 -F s )+(1 - x)y(P s0 -E s2 -E s4 -F s )+(1 - x)(1 - y)(P s0 -E s2 -E s4 -F s )

[0171]

[0172] The shipping company's replication state equation is:

[0173]

[0174] Example

[0175] In this embodiment, based on the tripartite evolutionary game dynamics model, the strategic choices of the government, port enterprises, and shipping companies are analyzed.

[0176] 1. When the government's strategy reaches stability, it must satisfy the stability theorem of differential equations, that is, F(x) = 0 and dF(x) / dx < 0.

[0177] Let When y = y * At this time, F(x) = 0 always holds, which indicates that regardless of the value of x, F(x) is stable, that is, the government's strategic choice is not affected by time.

[0178] When y ≠ y * And when F(x) = 0, we get x = 0 and x = 1 as two possible equilibrium points of F(x).

[0179] When 0 < y < y * < 1, F′(0) < 0, F′(1) > 0, which means that under this condition, x = 0 is an evolutionary stable point, indicating that when the probability of port enterprises choosing to build green methanol facilities is less than y * At this time, the government will not promote the development of green methanol.

[0180] When 0 < y * < y < 1, F′(0) > 0, F′(1) < 0, which means that under this condition, x = 1 is an evolutionary stable point, indicating that when the probability of port enterprises choosing to build green methanol is greater than y * At this time, the government will promote the development of green methanol.

[0181] 2. When the port enterprise's strategy reaches stability, it must satisfy the stability theorem of differential equations, that is, F(y) = 0 and dF(y) / dy < 0.

[0182] Let At this time, when z = z * At this time, F(y) = 0 always holds, which indicates that regardless of the value of y, F(y) is stable, that is, the strategic choice of port enterprises is not affected by time.

[0183] When z ≠ z * At this time, we get y = 0 and y = 1 as two possible equilibrium state points of F(y).

[0184] When 0 < z < z * < 1, F′(0) < 0, F′(1) > 0, which means that under this condition, y = 0 is an evolutionary stable point, indicating that when the probability of shipping companies choosing to retrofit green methanol receiving equipment is less than z * At this time, port enterprises will not build new green methanol facilities.

[0185] When 0 < z *When \(z \lt 1\), \(F'(0)\gt0\) and \(F'(1)\lt0\), which indicates that \(y = 1\) is an evolutionarily stable point under this condition, meaning that when the probability of the shipping company choosing to retrofit the green methanol receiving facility is greater than \(z\) * the port enterprise will build green methanol facilities.

[0186] 3. When the strategy of the shipping company reaches stability, it must satisfy the stability theorem of differential equations, that is, \(F(z)=0\) and \(dF(z) / dz \lt 0\).

[0187] Let When \(x = x\) * \(F(z)=0\) always holds, which shows that regardless of the value of \(z\), \(F(z)\) is stable, that is, the strategic choice of the shipping company is not affected by time;

[0188] When \(x\neq x\) * we get \(z = 0\) and \(z = 1\) as two possible equilibrium state points of \(F(z)\).

[0189] When \(0 \lt x \lt x\) * \(< 1\), \(F'(0)\lt0\) and \(F'(1)\gt0\), which indicates that \(z = 0\) is an evolutionarily stable point in this case, meaning that when the probability of the government choosing to promote green methanol is less than \(x\) * the shipping company will not retrofit the green methanol receiving equipment.

[0190] When \(0 \lt x\) * \(< x \lt 1\), \(F'(0)\gt0\) and \(F'(1)\lt0\), which indicates that \(z = 1\) is an evolutionarily stable point in this case, meaning that when the probability of the government choosing to promote green methanol is greater than \(x\) * the shipping company will retrofit the green methanol receiving equipment.

[0191] According to the requirement that \(E7(1,1,0)\) reaches a stable state in the initial stage, \(E\) g1 \(+E\) g2 \(+P\) g4 \(+\omega1E\) p1 \(\lt P\) g1 \(+E\) s3 \(+\mu\) p \(U\) p \(\mu\) p \(U\) p \(+E\) p1 \(\lt \omega1E\) p1 \(+E\) p2 and \(E\) ps \(+P\) s1 \(+\omega3E\) s1 \(+E\) s3 \(\lt F\) s1 \(+E\) s1 \(+\mu\) s \(U\) s . Figure 5It depicts the three-party evolutionary game process with unfixed initial strategies, which converges to the equilibrium point (1, 1, 0), indicating that the ESS of the government, port enterprises, and shipping companies is {promote, construct, do not transform}. Figure 5 The shown evolutionary process indicates that regardless of the initial strategies of the three stakeholders, when the constraint conditions are met, the equilibrium point (1, 1, 0) is the ESS of the system. This result shows that in the initial stage, as an advocate, the government gives priority to encouraging port enterprises to transform to green methanol energy, and port enterprises, as participants, promote the development of new green methanol energy. However, due to reasons such as the high transformation cost of shipping companies, imperfect transformation technology, and high cost of green methanol in the initial stage, in order to maximize their own interests, they decide to wait and see first.

[0192] In the growth stage, at this time, the requirement for E8(1, 1, 1) to reach a stable state, E g1 +E g2 +E g3 +P g2 +P g4 +ω3E s1 +ω2F p +ω1E p1 <P g1 +P g3 +μ p U p +μ s U s ,E p1 +E ps +F p +μ p U p <E p2 +P p1 +ω1E p1 +ω2F p and E s1 +F s1 +μ s U s <E ps +E s3 +P s1 +ω3E s1 。 Figure 6 It depicts the three-party evolutionary game process with unfixed initial strategies, which converges to the equilibrium point (1, 1, 1), indicating that the ESS of the government, port enterprises, and shipping companies is {promote, construct, transform}. Figure 6The evolution process shown shows that no matter what the initial strategies of the three stakeholders are, when the constraints are met, the equilibrium point (1,1,1) is the ESS of the system. This result shows that in the development stage, the government, as an advocate, encourages port enterprises and shipping companies to transform green methanol energy, and port enterprises and shipping companies, as participants, promote the development of green methanol new energy. Due to the increase in government subsidies and the maturity of port enterprises and shipping companies in the construction and transformation of green methanol technology, the gradual clarification of transportation routes, and the reduction of green methanol costs, the strategies of the three stakeholders eventually converge to the optimal equilibrium state.

[0193] In the mature stage, E4(0,1,1) reaches the stable state requirement, P g1 +P g3 +μ p U p +μ s U s <E g1 +E g2 +E g3 +P g2 +P g4 +ω1E p1 +ω2F p +ω3E s1 , E p1 +F p <P p1 and E s1 +F s2 <P s1 . Figure 7 The three-party evolutionary game process with unfixed initial strategies is depicted, and the process converges to the equilibrium point (0,1,1), indicating that the ESS of the government, port enterprises and shipping companies is {no promotion, construction, transformation}. Figure 7 The evolution process shown shows that no matter what the initial strategies of the three stakeholders are, when the constraints are met, the equilibrium point (0,1,1) is the ESS of the system. This result shows that in the mature stage, the application market of green methanol has formed a certain scale and no longer requires government intervention. The government's behavioral strategy will change to passive governance. Since the benefits of port enterprises and shipping companies have been significantly improved after using green methanol, in this case, the construction and transformation of green methanol will gradually become a recognized choice in the shipping industry. Finally, in the mature stage, the government will gradually withdraw from the market, and port enterprises and shipping companies will become the main players.

[0194] In order to better study and evaluate the impact of key parameters on the three-way evolution results and trajectories and provide guidance, this paper chooses to s1 , U s and E g1Perform assignment analysis under the condition of meeting the equilibrium point E8(1, 1, 1). The purpose is not only to better study which parameters affect the transition from the initial stage to the growth stage, but also to give targeted opinions to better promote the maturity of green methanol. Therefore, considering the equilibrium point and combining the actual situation in this section, let the initial willingness be x = 0.7, y = 0.5, z = 0.5.

[0195] At F s1 = 2, F s1 = 8, F s1 = 16, while keeping other parameters unchanged, the simulation results Figure 8 are shown as follows. From Figure 8 it can be seen that when F s1 = 2, x, y, and z continue to grow until they finally tend to 1, indicating that when the price of green methanol is low, the application of green methanol will develop rapidly. When F s1 = 8, although x, y, and z continue to grow, the growth rate is less than that when F s1 = 2. This shows that when the government, port enterprises, and shipping companies all have a positive attitude towards the construction of green methanol and the fees paid by ships for green methanol are less, shipping companies will accelerate the transformation from traditional energy to green methanol energy. However, when F s1 = 16, x and y continue to grow to 1, but z gradually weakens from the initial willingness of 0.5 to 0. It can be seen that appropriate green methanol fees can effectively increase the willingness of ships to use green methanol, thus accelerating the optimal strategic choices of all stakeholders.

[0196] At U s = 4, U s = 15, U s = 30, while keeping other parameters unchanged, the simulation results are as Figure 9 shown as follows. From Figure 9 it can be seen that when U s = 4, x, y, and z continue to grow until they finally tend to 1. This indicates that when the government's punishment for fraud compensation of shipping companies is small, it can promote the popularization of green methanol. However, when U s = 155, it can be clearly seen that the growth rate of shipping companies is slow, which will affect the popularization of green methanol to a certain extent. But when U s=30, it is found that z will continue to decrease and eventually tend to 0, indicating that at this time, due to the high penalty for fraud, it may even be much greater than the benefit of ships from green methanol and the cost of transforming equipment to receive green methanol, so that shipping companies have a negative attitude. It can be seen that when the government's penalty for fraudulent subsidies by shipping companies is kept in an appropriate range, it will promote or even accelerate the transformation of ships from using traditional energy to green methanol. In the early stage, the government can keep the penalty low and increase the inspection efforts to ensure that the government's inspection costs are compensated while the ship is modified, thereby promoting the transformation of shipping companies. In the mature stage, when the market has already highly praised green methanol, the penalty can be increased to ensure that shipping companies will not commit fraudulent subsidies.

[0197] In E g1 =1,E g1 =5, E g1 = 10, keeping other parameters unchanged, the simulation results are as follows Figure 10 As shown. Figure 10 It can be seen that when E g1 =1, x, y and z continue to grow until they eventually approach 1, indicating that when the government's cost of promoting green methanol is small, it will promote the three stakeholders to develop in a positive direction towards green methanol. g1 =5 and E g1 =10, y and z continue to grow to 1, but x gradually decreases from the initial willingness of 0.7 to 0. g1 = 10, the rate at which x decreases to 0 is greater than E g1 =5, the rate at which x decreases to 0. This shows that when the three stakeholders each take {promote, build, and transform}, if the government increases the promotion cost at this time, the government can withdraw from the market earlier, which is conducive to better transformation to the mature stage.

[0198] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for the development of green methanol for shipping based on evolutionary game and system dynamics, characterized in that Including: Regarding the government, port enterprises, and shipping companies during the development of green methanol for shipping as the main bodies, respectively analyze the strategic choices; Construct an evolutionary game model according to the strategic choices; Establish a payoff matrix based on the evolutionary game model; Analyze the stability of the system equilibrium point in the evolutionary game model, and analyze the development process of green methanol according to the life cycle theory; Construct a three-party evolutionary game dynamics model to realize the research on the development process of green methanol for shipping.

2. The method for the development of green methanol for shipping based on evolutionary game and system dynamics according to claim 1, characterized in that The analysis of strategic choices specifically includes: Represent the strategic choice set of the government as: G = (G1, G2), where promotion is G1 and non-promotion is G2. Represent the strategic choice set of port enterprises as: P = (P1, P2), where construction is P1 and non-construction is P2. Represent the strategic choice set of shipping companies as S = (S1, S2), where retrofit is S1 and non-retrofit is S2; In the initial stage, the probabilities of the government choosing promotion or non-promotion are x and 1 - x respectively, the probabilities of port enterprises choosing construction or non-construction are y and 1 - y respectively, and the probabilities of shipping companies choosing retrofit or non-retrofit are z and 1 - z respectively.

3. The green methanol development method for shipping based on evolutionary game and system dynamics according to claim 1, characterized in that, The construction of the evolutionary game model according to the strategic choices specifically includes: Denote the government's initial social welfare as P g0 When the government chooses the G1 strategy, the costs of policy implementation, promotion, and supervision are E g1 After the ship completes the green methanol installation, the benefit brought to the government is P g1 After the port enterprise completes the green methanol installation, the benefit brought to the government is P g3 When the government chooses the G1 strategy and the port enterprise chooses the P1 strategy, the cost for the government to check whether the port enterprise has fraudulent subsidy behavior is E g2 The port enterprise has a probability of μ p to implement fraudulent subsidy behavior. If there is fraudulent subsidy, the government will definitely detect it and impose a penalty on the enterprise. The fraud penalty amount is U p When the government chooses the G1 strategy and the shipping company chooses the S1 strategy, the cost for the government to check whether the shipping company has fraudulent subsidy behavior is E g3 The shipping company has a probability of μ s to implement fraudulent subsidy behavior. If there is fraudulent subsidy, the government will definitely detect it and impose a penalty on the company. The fraud penalty amount is U s When the government chooses the G2 strategy, after the ship completes the green methanol installation, the benefit brought to the government by the port enterprise is P g2 After the ship completes the green methanol installation, the benefit brought to the government by the shipping company is P g4 When the government chooses the G1 strategy and the port enterprise chooses the P1 strategy, the government conducts the completion acceptance work of green methanol for the port enterprise and rewards and subsidizes the construction work of the port enterprise. The government's reward coefficient for the port enterprise to build green methanol facilities is ω1; the government provides an operation subsidy to the port that completes the use of green methanol receiving facilities as required, and the subsidy coefficient is ω2; when the government chooses the G1 strategy and the shipping company chooses the S1 strategy, for each ship renovated by the shipping company, the government's subsidy coefficient for the shipping company is ω3; when the government chooses the G1 strategy, the port enterprise chooses the P2 strategy, and the shipping company chooses the S2 strategy, the government will supervise the port enterprise and the shipping company, and the penalty cost for the port enterprise to resist the construction of green methanol facilities is E p2 The penalty cost for the shipping company to resist the construction of green methanol facilities is E s3 ; Express the initial income of the port enterprise as P p0 , E p1 is the construction cost of the green methanol facility, and the expenditure of the port for purchasing green methanol is F p , when the government chooses the G1 strategy and the port enterprise chooses the P1 strategy, the construction subsidy and operation subsidy obtained by the port enterprise from the government are ω1E p1 and ω2E p ; when the local government does not have a green methanol promotion policy, the port enterprise will suffer losses in other aspects such as competition as E p3 ; when the government implements the policy, the port enterprise gives a subsidy E to the shipping company refueling with green methanol ps , when the port enterprise chooses the P1 strategy and the shipping company chooses the S2 strategy, the port enterprise will not choose to purchase green methanol on the premise of maximizing its own interests. Express the initial revenue of the shipping company as P s0 When the shipping company chooses Strategy S1, the increased revenue brought to the shipping company by using green methanol is P s1 The cost of retrofitting the ship's green methanol receiving equipment is E s1 The berthing cost incurred by the ship during port stay is E s2 ; When there are no government policies related to green methanol, the shipping company will suffer losses in terms of competition by E s4 When the government chooses Strategy G1 and the shipping company chooses Strategy S1, the cost for the ship to obtain green methanol under the preferential policy is F s1 The subsidy amount for the shipping company is ω3E s1 When the government chooses Strategy G2 and the shipping company chooses Strategy S1, the cost for the ship to pay for green methanol is F s2 The cost of the ship using traditional fuel is F s .

4. The method for the development of green methanol for shipping based on evolutionary game and system dynamics according to claim 1, wherein, The establishment of the payoff matrix based on the evolutionary game model specifically includes: When the strategic choice of the government is promotion G1, the strategic choice of port enterprises is construction P1, and the strategic choice of shipping companies is retrofit S1, the payoffs of the three parties are respectively: Government payoff: P g0 +P g1 +P g3 -E g1 -E g2 -E g3 -ω1E p1 -ω2F p -ω3E s1 +μ p U p +μ s U s Port enterprise revenue: P p0 +P p1 +ω1E p1 +ω2E p -E p1 -E ps -F p -μ p U p Shipping company revenue: P s0 +P s1 +ω3E s1 -E s1 -E s2 +E ps -F s1 -F s -μ s U s ; When the strategic choice of the government is promotion G1, the strategic choice of port enterprises is construction P1, and the strategic choice of shipping companies is non-retrofit S2, the payoffs of the three parties are respectively: Government revenue: P g0 +P g1 -E g1 -E g2 -ω1E p1 +E s3 +μ p U p Port enterprise revenue: P p0 + ω1E p1 - E p1 - μ p U p Shipping company revenue: P s0 -E s2 -E s3 -F s ; When the strategic choice of the government is promotion G1, the strategic choice of port enterprises is non-construction P2, and the strategic choice of shipping companies is retrofit S1, the payoffs of the three parties are respectively: Government revenue: P g0 +P g3 +E p2 -E g1 -E g3 -ω3E s1 +μ s U s Port enterprise revenue: P p0 -E p2 Shipping company revenue: P s0 +P s1 +ω3E s1 -E s1 -E s2 -F s1 -F s -μ s U s ; When the strategic choice of the government is promotion G1, the strategic choice of port enterprises is non-construction P2, and the strategic choice of shipping companies is non-retrofit S2, the payoffs of the three parties are respectively: Government revenue: P g0 -E g1 +E s3 +E p2 Port enterprise revenue: P p0 -F p2 Shipping company revenue: P s0 -E s2 -E s3 -F s ; When the strategic choice of the government is non-promotion G2, the strategic choice of port enterprises is construction P1, and the strategic choice of shipping companies is retrofit S1, the payoffs of the three parties are respectively: Government revenue: P g0 +P g2 +P g4 Port enterprise revenue: P p0 +P p1 -E p1 -E p3 -F p Shipping company revenue: P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s ; When the strategic choice of the government is non-promotion G2, the strategic choice of port enterprises is construction P1, and the strategic choice of shipping companies is non-retrofit S2, the payoffs of the three parties are respectively: Government revenue: P g0 +P g4 Port enterprise revenue: P p0 -E p1 -E p3 Shipping company revenue: P s0 -E s2 -E s4 -F s When the strategic choice of the government is non-promotion G2, the strategic choice of port enterprises is non-construction P2, and the strategic choice of shipping companies is retrofit S1, the payoffs of the three parties are respectively: Government revenue: P g0 +P g2 Port enterprise revenue: P p0 -E p3 Shipping company revenue: P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s When the strategic choice of the government is non-promotion G2, the strategic choice of port enterprises is non-construction P2, and the strategic choice of shipping companies is non-retrofit S2, the payoffs of the three parties are respectively: Government revenue: P g0 Port enterprise revenue: P p0 -E p3 Shipping company revenue: P s0 -E s2 -E s4 -F s 。 5. The method for the development of green methanol for shipping based on evolutionary game and system dynamics according to claim 1, wherein The analysis of the stability of the system equilibrium point in the evolutionary game model and the analysis of the development process of green methanol according to the life cycle theory specifically include: The Jacobian matrix of the three-party evolutionary game of the government, port enterprises, and shipping companies is: According to Lyapunov's first law: If all the eigenvalues of the Jacobian matrix have negative real parts, then this equilibrium point is an asymptotically stable point; if one of the eigenvalues of the Jacobian matrix has a positive real part, then this equilibrium point is an unstable point; According to the life cycle theory, the development of green methanol is divided into the initial stage, the growth stage and the mature stage; in the initial stage, the strategic choice of the government is to promote, port enterprises build green methanol receiving facilities, and shipping companies have a negative attitude towards the transformation of green methanol facilities; in the growth stage, the strategic choice of the government is to promote, port enterprises build green methanol receiving facilities, and shipping companies have a positive attitude towards green methanol facilities; in the mature stage, the willingness of port enterprises and shipping companies to participate in green methanol construction work increases and does not require government intervention.

6. The green methanol development method for shipping based on evolutionary game and system dynamics according to claim 1, characterized in that, The construction of the tripartite evolutionary game dynamics model specifically includes: Let the expected returns of the government's strategic choices of promoting and not promoting be denoted as E 11 and E 12 respectively. The average return is Then: E 11 = yz(P g0 + P g1 + P g3 - E g1 - E g2 - E g3 - ω1E p1 - ω2F p - ω3E s1 + μ p U p +μ s U s ) +y(1 - z)(P g0 +P g1 -E g1 -E g2 -ω1E p1 +E s3 +μ p U p ) +(1 - y)z(P g0 +P g3 +E p2 -E g1 -E g3 -ω3E s1 +μ s U s )+(1 (1 - y)(1 - z)(P g0 -E g1 +E s3 +E p2 ) E 12 = yz(P g0 + P g2 + P g4 ) + y(1 - z)(P g0 + P g4 ) + (1 - y)z(P g0 + P g2 ) + (1 (1 - y)(1 - z)P g0 The replicator dynamic equation of the government is: The expected returns of the strategic choices of building and not building for port enterprises are respectively denoted as E 21 and E 22 . The average return is Then: E 21 = xz(P p0 + P p1 + ω1E p1 + ω2E p - E p1 - E ps - F p - μ p U p ) +x(1 - z)(P p0 + ω1E p1 - E p1 - μ p U p ) +(1 - x)z(P p0 +P p1 -E p1 -E p3 -F p )+(1 - x)(1 - z)(P p0 -E p1 -E p3 ) E 22 = xz(P p0 - E p2 ) + x(1 - z)(P p0 - E p2 ) + (1 - x)z(P p0 - E p3 ) + (1 - x)(1 - z)(P p0 - E p3 ) The replicator dynamic equation of port enterprises is: Denote the expected returns of the shipping company's strategic choices of transformation and non - transformation as E 31 and E 32 , and the average return is Then: E 31 = xy(P s0 + P s1 + ω3E s1 - E s1 - E s2 + E ps - F s1 - F s - μ s U s ) +x(1 - y)(P s0 +P s1 +ω3E s1 -E s1 -E s2 -E s1 -F s -μ s U s ) +(1 - x)y(P s0 +P s1 -E s1 -E s2 -E s4 -F s2 -F s )+(1 - x)(1 - y) (P s0 +P s1 -E s1 -E s2 -E s4 -E s2 -F s ) E 32 = xy(P s0 - E s2 - E s3 - F s ) + x(1 - y)(P s0 - E s2 - E s3 - F s ) + (1 - x)y(P s0 - E s2 - E s4 - F s ) + (1 - x)(1 - y)(P s0 - E s2 - E s4 - F s ) The replicator state equation of shipping companies is:

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