Coal-fired power plant inventory management system and method based on supply and demand relationship

Abstract

The application provides a coal-fired power plant inventory management system and method based on a supply and demand relationship, relates to the technical field of coal-fired power plant inventory management, and the initial coal inventory, historical data information of coal consumption in each period in a historical database is called, an inventory and consumption model is constructed based on the historical data information, and a storage and consumption output relationship in the period is obtained; a coal inventory restriction condition is established according to the storage and consumption output relationship, and the coal inventory is generated according to the coal inventory restriction condition; the coal inventory is obtained, the total inventory cost of the coal-fired power plant inventory management system and the purchase time of the coal-fired power plant inventory management system are calculated, and the risk and loss of coal supply are effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal-fired power plant inventory management, in particular to a coal-fired power plant inventory management system and method based on supply and demand relationship. BACKGROUND

[0002] With the deepening of the reform of the electricity market, the market competition mechanism is gradually improved, and the power coal generation capacity enters the electricity market. The coal-fired power plant not only needs to provide stable and efficient power products for residents' life and industry, but also needs to ensure its own production safety and improve power generation efficiency. In order to prevent the power coal supply from being interrupted and causing fire outage, the power plant will set a certain amount of power coal inventory. When formulating the power generation and procurement plan, the uncertainty of the power coal supply chain and the bidding for the grid under the electricity market environment needs to be considered, which means that the power plant has more self-management right and also bears greater profit pressure. In order to ensure the maximum profit under the condition of stable power supply, the key is to optimize the power coal procurement quantity and determine a more reasonable power coal inventory level.

[0003] The electricity generated by the coal-fired power plant through the burning of power coal is called coal electricity. The stability of the power coal supply chain operation lays the foundation for large-scale coal electricity production. However, the structural contradictions of the power coal supply chain in China have been interfering with the inventory control decisions of the power plant for many years.

[0004] As an energy material, the transportation and storage of power coal are relatively simple. However, due to the great uncertainty of coal production at the upper end and consumption at the lower end, the coal-fired power plant generally signs a medium and long-term order agreement with the coal enterprise, i.e. the upstream coal mine, and the procurement quantity can basically meet the power generation demand. When the market gradually opens up and the price of power coal slowly stabilizes through market competition, the power plant may choose higher quality and higher realization rate of power coal in the market to meet part of the power generation demand. At this time, the power plant bears the risk, but obtains more benefits.

[0005] At present, there is a phenomenon of further expansion of electricity demand, increase of installed capacity of thermal power in some areas, and increase of demand for power coal. However, due to the lack of upstream production capacity and transportation capacity and other circumstances, there are still occasional problems of power supply tension and instability in some areas. Generally speaking, in order to avoid the problem of unstable power coal supply as much as possible, the power plant will set a high safety inventory to effectively reduce the risk and loss of coal supply.

[0006] At present, the research on power coal or coal (coal) in China mainly focuses on how to reduce the cost. Due to the strong dependence on coal as a primary energy in China, and the problem of non-correspondence between energy and load distribution, it directly leads to a large amount of funds occupied by storage and transportation costs. At the same time, China is in the key period of energy transformation, and the demand for cost control and optimization of coal-fired power plants is further highlighted, so optimizing the power coal inventory and transportation problem becomes an important way to reduce cost and improve efficiency. SUMMARY

[0007] In order to solve the above technical problems, the present application provides a coal-fired power plant inventory management method based on supply and demand relationship, comprising the following steps:

[0008] S1, retrieve the initial coal inventory, coal consumption history data information in each period in the historical database, build an inventory and consumption model based on the historical data information, and obtain the storage and consumption output relationship in the period;

[0009] S2, establish a coal inventory limit condition according to the output relationship value of the inventory and consumption model of step S1, and generate a coal inventory according to the coal inventory limit condition;

[0010] S3, obtain the coal inventory S, calculate the total order cost, total inventory cost and purchase expectation function of the coal-fired power plant inventory system.

[0011] Further, in step S1, the inventory and consumption model is:

[0012]

[0013] Wherein, y(t) represents the output relationship value of the inventory and consumption model, x(t) represents the initial coal inventory, b represents the coal consumption, a represents the period, t represents the cumulative time, t=a, 2a,…, na; n represents the number of periods, and e represents the base number of natural logarithm.

[0014] Further, in step S1, the retrieved initial coal inventory, coal consumption history data information in each period is preprocessed, and is divided into test set and training set. The coal production, storage, consumption and sales model is trained by using the training set, and the trained inventory and consumption model is tested by using the test set. When the test result is higher than the preset standard, the trained inventory and consumption model is output.

[0015] Further, in step S2, the coal inventory S expression is as follows in the time t∈[a,na]:

[0016]

[0017] Wherein, y(t) represents the output relationship value of the inventory and consumption model, P represents the coal inventory rate, and U represents the coal inventory rate.

[0018] Further, in step S3,

[0019] The total ordering cost TR of the coal-fired power plant inventory system at time t is a function of:

[0020] TR = OR + {HR x t x |(S + Q) - D| x P(D) + CR x Q + PC x |(S + Q) - D| x P(D)};

[0021] OR is the fixed ordering cost when ordering from the coal storage and distribution base, HR is the storage cost of the coal-fired power plant inventory per unit of time per unit of weight, S is the coal inventory of the coal-fired power plant at time t, Q represents the ordering quantity of the coal-fired power plant inventory to the coal storage and distribution base, D is the coal demand of the coal-fired power plant inventory at time t, P(D) is the probability of the coal demand D of the coal-fired power plant inventory at time t, CR is the transportation cost of the coal from the coal storage and distribution base to the coal-fired power plant inventory per unit of weight, and PC is the loss cost of the coal-fired power plant inventory per unit of weight in case of stockout.

[0022] Further, the total inventory cost TR of the coal-fired power plant inventory system at time t is a function of: Z

[0023] TR Z = δ(RR - 1) x TR;

[0024] Wherein, RR is the ordering anticipation function of the coal-fired power plant inventory, and δ is the ordering anticipation function coefficient:

[0025]

[0026] The ordering anticipation function RR of the coal-fired power plant inventory is:

[0027]

[0028] Wherein, LT is the ordering lead time of the coal-fired power plant inventory, σ is the daily demand standard deviation of the coal-fired power plant inventory, z is the safety factor of the coal-fired power plant inventory, and μ is the daily demand expectation of the coal-fired power plant inventory.

[0029] Further, the coal inventory restriction condition is that the sum of the existing inventory quantity and the ordering quantity of the coal-fired power plant inventory does not exceed its storage capacity when ordering; the ordering quantity of the coal-fired power plant inventory does not exceed the maximum transportation capacity; and the ordering quantity of the coal-fired power plant inventory is not less than the minimum transportation unit.

[0030] ​The application further provides a coal-fired power plant inventory management system based on a supply-demand relationship, characterized by being used for implementing the coal-fired power plant inventory management method, and comprising a historical database, an inventory and consumption model construction unit, a restriction condition establishment unit and an inventory management unit.

[0031] The inventory and consumption model construction unit is used for calling initial coal inventory and historical data information of coal consumption in each period in the historical database, constructing an inventory and consumption model based on the historical data information, and obtaining an inventory-consumption output relationship in the period.

[0032] The restriction condition establishment unit is used for establishing a coal inventory restriction condition according to the inventory-consumption output relationship of the inventory and consumption model construction unit, and generating a coal inventory based on the coal inventory restriction condition.

[0033] The inventory management unit is used for obtaining the coal inventory, and calculating total ordering cost, total inventory cost and a purchase expectation function of the coal-fired power plant inventory system.

[0034] Further, the inventory management unit comprises a laser acquisition instrument, a three-dimensional reconstruction unit, a judgment unit, an ordering unit and a calculation unit.

[0035] The laser acquisition instrument is used for acquiring profile data points of a coal pile in the coal-fired power plant inventory and digital signs of a coal yard site.

[0036] The three-dimensional reconstruction unit is used for acquiring the profile data points and the digital signs of the coal yard site, completing three-dimensional reconstruction of the coal pile in the coal-fired power plant inventory, and generating a coal inventory S.

[0037] The judgment unit is used for judging whether the total inventory of the coal-fired power plant inventory system is reduced to a minimum inventory.

[0038] The ordering unit is used for uniformly ordering from a coal storage and distribution base when the judgment unit judges whether the total inventory of the coal-fired power plant inventory system is reduced to the minimum inventory.

[0039] The calculation unit is used for calculating the total ordering cost, the total inventory cost and the purchase expectation function of the coal-fired power plant inventory system.

[0040] Compared with the prior art, the application has the following beneficial technical effects:

[0041] Historical data on initial coal inventory and coal consumption for each period are retrieved from the historical database. An inventory and consumption model is constructed based on this data. The model is trained using a training set and tested using a test set. When the test results exceed a preset standard, the trained inventory and consumption model is output, revealing the inventory-consumption output relationship for each period. Based on this relationship, coal inventory constraints are established. A variable integral function is used as the constraint, and the cumulative value of the constraint variable over a period is calculated to generate the coal inventory. The coal inventory is then used to calculate the total ordering cost, total inventory cost, and expected purchase function of the coal-fired power plant inventory system, effectively reducing the risks and losses associated with coal supply. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of the coal-fired power plant inventory management method based on supply and demand relationship of the present invention.

[0044] Figure 2 This is a schematic diagram of the structure of the coal-fired power plant inventory management system based on supply and demand relationship of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] In the accompanying drawings of specific embodiments of the present invention, in order to better and more clearly describe the working principle of each component in the system and show the connection relationship of each part in the device, only the relative positional relationship between each component is clearly distinguished. It does not constitute a limitation on the signal transmission direction, connection sequence, or size, dimension, and shape of each part within the component or structure.

[0047] like Figure 1 The diagram shown is a flowchart of the coal-fired power plant inventory management method based on supply and demand relationship of the present invention, which includes the following steps:

[0048] Step S1, retrieve the initial coal inventory and historical data information of coal consumption in each period in the historical database, build an inventory and consumption model based on the historical data information, and obtain the storage and consumption output relationship in the period.

[0049] The historical data information of the initial coal inventory and coal consumption in each period is preprocessed, and is divided into a test set and a training set, with a ratio of 4:6; the preprocessed historical data information is used to build an inventory and consumption model.

[0050] The training set is used to train the inventory and consumption model, and the test set is used to test the trained inventory and consumption model. When the test result is higher than the preset standard, the trained inventory and consumption model is output.

[0051] The inventory and consumption model is:

[0052]

[0053] Wherein, y(t) represents the output relationship value of the inventory and consumption model, x(t) represents the initial coal inventory, b represents the coal consumption, a represents the period, t represents the cumulative time, t=a, 2a,…, na; n represents the number of periods, and e represents the base of natural logarithm.

[0054] In the preferred embodiment, the LSTM model is used to train the inventory and consumption model, the historical initial coal inventory and coal consumption in recent years are obtained as training samples, the SSA algorithm is used to decompose and reconstruct the training data, and the normalization processing is performed; the LSTM network input layer, hidden layer and output layer parameters are constructed; the initialization of the LSTM network weight, bias and state is set; the n-layer LSTM network is trained and the optimal network structure is stored.

[0055] The LSTM model contains three control modules, namely the input module, the memory module and the output module. The input module determines how much current input data is input into the LSTM model, the memory module mainly determines the retention of historical data, and how much historical data needs to be used as the current output value is controlled by the output module.

[0056] Step S2, according to the output relationship value of the inventory and consumption model of step S1, establish the coal inventory restriction condition, and generate the coal inventory according to the coal inventory restriction condition.

[0057] The variable integral function is used as the coal inventory restriction condition, and the variable integral function is applied to the restriction condition variable expression to calculate the cumulative value of the restriction condition variable in a period of time.

[0058] In the time t∈[a, na], the expression of the coal inventory S is as follows:

[0059]

[0060] wherein y(t) represents the output value of the inventory-consumption model, P represents the coal-in rate, and U represents the coal-out rate.

[0061] In step S3, the coal inventory S is obtained, and the total ordering cost, the total inventory cost, and the order anticipation function of the coal inventory system of the coal-fired power plant are calculated.

[0062] When the total inventory of the coal inventory system of the coal-fired power plant decreases to the minimum inventory, the information coordination center uniformly orders from the coal storage and distribution base on behalf of the coal-fired power plant inventory systems that need to order within the t period.

[0063] The function of the total ordering cost TR of the coal inventory system of the coal-fired power plant in the t period is:

[0064] TR = OR + {HR x t x |(S + Q) - D| x P(D) + CR x Q + PC x |(S + Q) - D| x P(D)};

[0065] OR is the fixed ordering cost when ordering from the coal storage and distribution base, HR is the storage cost of the coal per unit weight per unit time of the coal inventory of the coal-fired power plant, S is the coal inventory of the coal-fired power plant in the t period, Q represents the ordering quantity of the coal inventory of the coal-fired power plant to the coal storage and distribution base, D is the coal demand of the coal inventory of the coal-fired power plant in the t period, P(D) is the probability of the coal demand D of the coal inventory of the coal-fired power plant in the t period, CR is the transportation cost of the coal per unit weight from the coal storage and distribution base to the coal inventory of the coal-fired power plant, and PC is the loss cost of the coal per unit weight in case of shortage of the coal inventory of the coal-fired power plant.

[0066] In the preferred embodiment, the sum of the existing inventory of the coal inventory of the coal-fired power plant and the ordering quantity does not exceed the storage capacity when the coal inventory system of the coal-fired power plant orders; the ordering quantity of the coal inventory of the coal-fired power plant does not exceed the maximum transportation capacity; and the ordering quantity of the coal inventory of the coal-fired power plant is not less than the minimum transportation unit.

[0067] The function of the total inventory cost TR of the coal inventory system of the coal-fired power plant in the t period is: Z

[0068] TR Z = δ(RR - 1) x TR;

[0069] wherein RR is the order anticipation function of the coal inventory of the coal-fired power plant, and δ is the order anticipation function coefficient:

[0070]

[0071] The order anticipation function RR of the coal inventory of the coal-fired power plant is:

[0072] ​

[0073] LT = z * (σ + μ) + LT

[0074] As Figure 2 shown, it is a structure schematic diagram of the coal-fired power plant inventory management system based on supply and demand relationship, comprising: a historical database, an inventory and consumption model construction unit, a restriction condition establishment unit and an inventory management unit.

[0075] The inventory and consumption model construction unit is used to call the initial coal inventory and coal consumption historical data information in each period in the historical database, construct the inventory and consumption model based on the historical data information, and obtain the storage and consumption output relationship in the period.

[0076] In the preferred embodiment, the Vensim software can be used to simulate the inventory and consumption model, display the corresponding graphs or tables, and further evaluate the authenticity and feasibility of the simulation results. If the evaluation is passed, the inventory and consumption model can be put into use, and if problems are found in the evaluation, the inventory and consumption model is modified.

[0077] The restriction condition establishment unit is used to establish the coal inventory restriction condition according to the storage and consumption output relationship of the inventory and consumption model construction unit, and generate the coal inventory based on the coal inventory restriction condition.

[0078] The inventory management unit is used to obtain the coal inventory, calculate the total ordering cost, total inventory cost and expected function of the coal-fired power plant inventory system.

[0079] Preferably, the inventory management unit comprises a laser acquisition instrument, a three-dimensional reconstruction unit, a judgment unit, an ordering unit and a calculation unit.

[0080] The laser acquisition instrument collects the contour data points of the coal pile in the coal-fired power plant inventory and the digital sign of the coal field,

[0081] The three-dimensional reconstruction unit obtains the contour data points and the digital sign of the coal field, completes the three-dimensional reconstruction of the coal pile in the coal-fired power plant inventory based on VC++ and OpenGL platform, divides the three-dimensional space where the coal pile is located into grids, establishes the mathematical relationship between the three-dimensional space and the coal quantity, and generates the coal inventory S.

[0082] The judgment unit is used to judge whether the total inventory of the coal-fired power plant inventory system has fallen to the minimum inventory,

[0083] The order unit is configured to, when the judging unit judges that the total inventory of the coal-fired power plant inventory system decreases to the minimum inventory, inform the information coordination center to uniformly order the coal-fired power plant inventory system that needs to order from the coal storage and distribution base within a time period.

[0084] The calculating unit is configured to calculate the total order cost, the total inventory cost and the order expectation function of the coal-fired power plant inventory system.

[0085] In the above embodiments, the implementation can be achieved wholly or partially by software, hardware, firmware or any combination thereof. When implemented by software, the implementation can be achieved wholly or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are wholly or partially generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted by the computer-readable storage medium. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center and the like including one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), a semiconductor medium (for example, a solid state disk (SSD)) or the like.

[0086] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed in the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A coal-fired power plant inventory management method based on supply and demand relationship, characterized by, Comprise the following steps: S1, call the initial coal inventory, coal consumption history data information in each period in the historical database, based on the historical data information to build the inventory and consumption model, get the relationship between the storage and consumption output in the period; S2, according to the output relationship value of the inventory and consumption model of step S1, establish the coal inventory limit condition, generate the coal inventory according to the coal inventory limit condition; The variable integral function is used as the coal storage restriction condition, the variable integral function is applied to the restriction condition variable expression, and the cumulative value of the restriction condition variable in a period of time is calculated. In the time t∈[a, na], the expression of the coal storage S is as follows: Wherein, y(t) represents the output relationship value of the storage and consumption model, P represents the coal storage rate, and U represents the coal storage rate. S3, get the coal inventory S, calculate the total cost of ordering, the total cost of inventory and the expected function of the coal-fired power plant inventory system; The total ordering cost TR of the coal-fired power plant inventory system at t period is a function of: TR=OR+{HR×t×|(S+Q)-D|×P(D)+CR×Q+PC×|(S+Q)-D|×P(D)}; OR is the fixed ordering cost when ordering to the coal storage and distribution base, HR is the storage cost of the coal-fired power plant inventory per unit time per unit weight of dynamic coal, S is the coal inventory of the coal-fired power plant inventory at t period, Q represents the ordering quantity of the coal-fired power plant inventory to the coal storage and distribution base, D is the coal demand of the coal-fired power plant inventory at t period, P(D) is the probability of coal demand D of the coal-fired power plant inventory at t period, CR is the transportation cost of the coal-fired power plant inventory per unit weight of dynamic coal from the coal storage and distribution base, PC is the loss cost per unit weight of dynamic coal when the coal-fired power plant inventory is out of stock; Total inventory cost (TR) of a coal-fired power plant inventory system during period t. Z The function is: TR Z = δ(RR-1) x TR; Wherein, RR is the expected function of the coal-fired power plant inventory, δ is the expected function coefficient: The function RR of the incoming order expectation for the coal power plant stock is: Wherein, LT is the ordering lead time of the coal-fired power plant inventory, σ is the daily demand standard deviation of the coal-fired power plant inventory, z is the safety factor of the coal-fired power plant inventory, μ is the daily demand expectation of the coal-fired power plant inventory.

2. The coal-fired power plant inventory management method according to claim 1, characterized by, In step S1, the inventory and consumption model is: Wherein, y(t) represents the output relationship value of the inventory and consumption model, x(t) represents the initial coal inventory, b represents the coal consumption, a represents the period, t represents the cumulative time, t=a, 2a,…, na; n represents the number of periods, e represents the base of natural logarithm.

3. The coal-fired power plant inventory management method of claim 2, wherein, In step S1, the initial coal inventory, coal consumption history data information in each period is pretreated, and is divided into test set and training set, the coal inventory and consumption model is trained by using the training set, the trained inventory and consumption model is tested by using the test set, when the test result is higher than the preset standard, the trained inventory and consumption model is output.

4. The coal-fired power plant inventory management method of claim 1, wherein, The coal inventory limit condition is that the sum of the existing inventory of the coal-fired power plant inventory and the ordering quantity does not exceed its storage capacity when ordering; The ordering quantity of the coal-fired power plant inventory does not exceed the maximum transportation capacity; The ordering quantity of the coal-fired power plant inventory is not less than the minimum transportation unit.

5. A coal-fired power plant inventory management system based on supply and demand relationships, characterized in that, For realizing the coal-fired power plant inventory management method as claimed in any one of claims 1-4, comprising: a historical database, an inventory and consumption model construction unit, a limit condition establishment unit and an inventory management unit; The inventory and consumption model construction unit is used for calling the initial coal inventory, coal consumption history data information in each period in the historical database, based on the historical data information to build the inventory and consumption model, get the relationship between the storage and consumption output in the period; The restriction condition establishing unit is configured to establish a coal inventory restriction condition according to the stock and consumption model constructing unit, and generate the coal inventory quantity according to the coal inventory restriction condition; The inventory management unit is configured to obtain the coal inventory quantity, and calculate the total ordering cost, the total inventory cost and the ordering expectation function of the coal power plant inventory system.

6. The coal-fired power plant inventory management system of claim 5, wherein, The inventory management unit comprises a laser acquisition instrument, a three-dimensional reconstruction unit, a judgment unit, an ordering unit and a calculation unit. The laser acquisition instrument is configured to acquire profile data points of the coal pile in the coal power plant inventory and digital signs in the coal yard field. The three-dimensional reconstruction unit is configured to acquire the profile data points and the digital signs in the coal yard field, complete three-dimensional reconstruction of the coal pile in the coal power plant inventory, and generate the coal inventory quantity S. The judgment unit is configured to judge whether the total inventory of the coal power plant inventory system decreases to the minimum inventory. The ordering unit is configured to order the coal storage and distribution base when the judgment unit judges whether the total inventory of the coal power plant inventory system decreases to the minimum inventory. The calculation unit is configured to calculate the total ordering cost, the total inventory cost and the ordering expectation function of the coal power plant inventory system.

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