An economic evaluation method for compressed air energy storage power stations

Abstract

This invention discloses an economic evaluation method for compressed air energy storage power stations, belonging to the field of compressed air energy storage technology. The method includes: setting basic parameters for the compressed air energy storage power station and configuring the station; calculating the thermal system of the station based on the configuration; calculating the energy conversion efficiency of the unit based on the thermal system; and evaluating the economic efficiency of the compressed air energy storage power station based on the energy conversion efficiency and the construction cost. This method can evaluate the economic efficiency of a compressed air energy storage power station based on the energy conversion efficiency and the construction cost.

Description

Technical Field

[0001] This invention relates to an economic evaluation method for compressed air energy storage power stations, belonging to the field of compressed air energy storage technology. Background Technology

[0002] New energy storage technologies will play a crucial role in the carbon peaking and carbon neutrality process. With the improvement of innovation capabilities in new energy storage technologies, the level of independent control over core technologies and equipment has been greatly enhanced, achieving significant progress in areas such as high safety, low cost, high reliability, and long lifespan.

[0003] Among numerous emerging energy storage technologies, compressed air energy storage (CAES) is an indirect, large-scale physical energy storage technology. During periods of low grid load, it uses a compressor to compress air, converting electrical energy into compressive potential energy for storage. During periods of high grid load, the high-pressure gas in the storage tank is released to drive a generator. CAES technology can be categorized into combustion-based and non-combustion-based methods. Non-combustion-based methods can be further divided into those without external heat sources (high-temperature adiabatic compression, medium-low-temperature adiabatic compression) and those with external heat sources (solar thermal, industrial waste heat, etc.). For the same capacity, non-combustion-based systems have higher energy conversion efficiency than combustion-based systems and emit no pollution, making them environmentally friendly. Like pumped hydro storage, CAES can solve the problem of large-capacity energy storage and offers significant advantages over electromagnetic and chemical energy storage, such as longer service life and easier maintenance. Developing large-scale CAES systems has become an important option for supporting intermittent renewable energy generation.

[0004] The selection of main unit parameters and the determination of gas storage boundary conditions in compressed air energy storage power plants are closely coupled and play a decisive role in the overall economic evaluation of the unit. Therefore, for clearly defined gas storage boundary conditions, it is necessary to conduct system integration and optimization design of compressed air energy storage power plants, select a scheme that balances efficiency and economy, and ensure that the unit obtains more returns in the energy storage market with lower investment. Summary of the Invention

[0005] The purpose of this invention is to provide an economic evaluation method for compressed air energy storage power stations, which can evaluate the economic performance of compressed air energy storage power stations based on the energy conversion efficiency of the unit and the cost of the compressed air energy storage power station.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An economic evaluation method for compressed air energy storage power stations includes:

[0008] Set the basic parameters of the compressed air energy storage power station and configure the compressed air energy storage power station;

[0009] Based on the configuration, calculate the thermal system of the compressed air energy storage power station;

[0010] Based on the aforementioned thermal system, the energy conversion efficiency of the computer group;

[0011] Based on the energy conversion efficiency of the unit and the cost of the compressed air energy storage power station, an economic evaluation of the compressed air energy storage power station is conducted.

[0012] Furthermore, setting the basic parameters of the compressed air energy storage power station and configuring the compressed air energy storage power station includes:

[0013] Set the installed capacity, energy storage duration, and energy release duration of the compressed air energy storage power station;

[0014] Select a gas storage facility and set its pressure fluctuation range;

[0015] The temperature range of the heat storage medium, the heat transfer difference of the heat exchange system, and the resistance loss of the compressed air energy storage power station are configured.

[0016] Furthermore, off-peak electricity storage is selected for energy storage, with a storage duration of 8 hours and an energy release duration of 4 to 6 hours.

[0017] Furthermore, abandoned salt caverns or artificial chambers are selected as gas storage facilities. The pressure fluctuation range for abandoned salt caverns is set to 1.5–2.5 MPa, and the pressure fluctuation range for artificial chambers is set to 5–8 MPa.

[0018] Furthermore, the calculation formula for the thermal system is shown in formula (1):

[0019]

[0020] In formula (1), i represents the i-th compressor segment, k represents the compressor segment number, n represents the compressor polytropic index, and P cin,i Let P be the inlet pressure of the i-th compressor segment. cout,i Let T be the outlet pressure of the i-th compressor segment. cin,i Let T be the inlet temperature of the i-th compressor segment. cout,i Let T be the outlet temperature of the i-th compressor segment. xure ΔT represents the high-temperature side temperature of the heat storage medium. he The heat transfer difference at the top of the heat exchanger is given by β, where β is the air turbine expansion ratio, and P is the heat transfer difference at the top of the heat exchanger. smin P0 is the minimum pressure of the gas storage tank, Pm is atmospheric pressure, m is the adiabatic index of the air turbine, and P0 is the minimum pressure of the gas storage tank. ein,i Let P be the inlet pressure of the i-th segment of the air turbine. eout,i Let T be the outlet pressure of the i-th air turbine. ein,iLet T be the inlet temperature of the i-th air turbine. eout,i Let E be the outlet temperature of the i-th air turbine. i Let E be the shaft power of the air turbine unit under a unit working fluid flow rate in the i-th segment, E0 be the design power of a single unit, and G be the shaft power of the air turbine unit under a unit working fluid flow rate. c For the mass flow rate of the compressor unit, t c For energy storage duration, G e For the mass flow rate of the air turbine unit, t e R is the energy release time, η is the air turbine efficiency, and R is the energy release duration. g R is the gas constant for air. g = 0.287 kJ / (kg·K).

[0021] Furthermore, the inlet temperature of the first stage compressor is determined by the meteorological conditions of the compressor's location, while the inlet temperature of the remaining compressor stages is set to 40°C; the number of air turbine stages is one less than the number of compressor stages, and each air turbine stage expands to atmospheric pressure P0 using a proportional expansion method.

[0022] Furthermore, the formula for calculating the energy conversion efficiency of the unit is shown in formula (2):

[0023]

[0024] In formula (2), w is the shaft power of the air turbine unit under unit working fluid flow rate, w i,c Let η be the shaft power of the compressor under unit working fluid flow rate in the i-th segment. i,c Let w0 be the isentropic efficiency of the compressor, w0 be the design power of a single unit, and η be the isentropic efficiency. sys This refers to the unit's energy conversion efficiency.

[0025] Furthermore, the cost analysis method for the compressed air energy storage power station includes:

[0026] Based on the aforementioned thermal system, dynamic balance calculations are performed on the thermal storage system within a single cycle to obtain the thermal storage medium and cooling water consumption.

[0027] Calculate the volume of the gas storage tank based on the gas consumption within a single cycle.

[0028] Based on the cooling water consumption and gas storage capacity, the cost of the compressed air energy storage power station is analyzed.

[0029] Furthermore, a dynamic balance calculation is performed on the thermal storage system within a single cycle, and the calculation formula is shown in formula (3):

[0030]

[0031] In formula (3), G xurec,iC represents the amount of heat storage medium used at the outlet of the i-th compressor. xure C represents the specific heat capacity of the heat storage medium. air For the specific heat of air at constant pressure, G xuree,i Let be the amount of heat storage medium used at the outlet of the i-th air turbine, where i = 1, 2, 3, 4…k-1.

[0032] Furthermore, the volume of the gas storage tank satisfies the relationship shown in formula (4):

[0033] Vρ(P smin ,T s )+G e t e =Vρ(P smax ,T s (4)

[0034] In formula (4), V is the gas storage volume, and T s P represents the temperature of the gas storage facility. smax P is the highest pressure in the gas storage facility. smin Set T to the minimum pressure of the gas storage facility. s The temperature is 40℃.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] The economic evaluation method for compressed air energy storage power stations provided by this invention evaluates the economic efficiency of compressed air energy storage power stations based on the energy conversion efficiency of the units and the cost of the compressed air energy storage power stations, which facilitates the rational and scientific selection of different installation schemes. Attached Figure Description

[0037] Figure 1 This is a flowchart of an economic evaluation method for a compressed air energy storage power station provided in an embodiment of the present invention. Detailed Implementation

[0038] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0039] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent. Unless otherwise specified, the embodiments of this application and the technical features within them can be combined with each other.

[0040] Example 1:

[0041] Figure 1This is a flowchart illustrating an economic evaluation method for a compressed air energy storage power station according to Embodiment 1 of the present invention. This flowchart merely shows the logical sequence of the method in this embodiment; however, in other possible embodiments of the present invention, different methods may be used, provided there are no conflicts. Figure 1 Complete the steps shown or described in the order indicated.

[0042] See Figure 1 The method in this embodiment specifically includes the following steps:

[0043] Step 1: Set the basic parameters of the compressed air energy storage power station and configure the compressed air energy storage power station;

[0044] Setting the basic parameters of a compressed air energy storage power station and configuring the compressed air energy storage power station includes the following steps:

[0045] Step A: Set the installed capacity, energy storage duration, and energy release duration of the compressed air energy storage power station;

[0046] When storing energy, off-peak electricity is selected, the energy storage duration is set to 8 hours, and the energy release duration is set to 4 to 6 hours.

[0047] Step B: Select a gas storage facility and set its pressure fluctuation range;

[0048] Abandoned salt caverns or artificial chambers were selected as gas storage facilities. The pressure fluctuation range for abandoned salt caverns was set to 1.5–2.5 MPa, and the pressure fluctuation range for artificial chambers was set to 5–8 MPa.

[0049] Step C: Configure the temperature range of the heat storage medium, the heat transfer difference of the heat exchange system, and the resistance loss of the compressed air energy storage power station.

[0050] Step 2: Calculate the thermal system of the compressed air energy storage power station based on the configuration;

[0051] The calculation formula for the thermal system is shown in formula (1):

[0052]

[0053] In formula (1), i represents the i-th compressor segment, k represents the compressor segment number, n represents the compressor polytropic index, and P cin,i Let P be the inlet pressure of the i-th compressor segment. cout,i Let T be the outlet pressure of the i-th compressor segment. cin,i Let T be the inlet temperature of the i-th compressor segment. cout,i Let T be the outlet temperature of the i-th compressor segment. xure ΔT represents the high-temperature side temperature of the heat storage medium. he The heat transfer difference at the top of the heat exchanger is given by β, where β is the air turbine expansion ratio, and P is the heat transfer difference at the top of the heat exchanger.smin P0 is the minimum pressure of the gas storage tank, Pm is atmospheric pressure, m is the adiabatic index of the air turbine, and P0 is the minimum pressure of the gas storage tank. ein,i Let P be the inlet pressure of the i-th segment of the air turbine. eout,i Let T be the outlet pressure of the i-th air turbine. ein,i Let T be the inlet temperature of the i-th air turbine. eout,i Let E be the outlet temperature of the i-th air turbine. i Let E be the shaft power of the air turbine unit under a unit working fluid flow rate in the i-th segment, E0 be the design power of a single unit, and G be the shaft power of the air turbine unit under a unit working fluid flow rate. c For the mass flow rate of the compressor unit, t c For energy storage duration, G e For the mass flow rate of the air turbine unit, t e R is the energy release time, η is the air turbine efficiency, and R is the energy release duration. g R is the gas constant for air. g = 0.287 kJ / (kg·K).

[0054] The inlet temperature of the first compressor is determined by the meteorological conditions of the compressor's location, while the inlet temperature of the other compressors is set to 40℃.

[0055] The number of air turbine sections is one less than the number of compressor sections, and each air turbine section expands to atmospheric pressure P0 using a proportional expansion method.

[0056] Step 3: Based on the thermal system, the energy conversion efficiency of the computer group;

[0057] The formula for calculating the energy conversion efficiency of the unit is shown in formula (2):

[0058]

[0059] In formula (2), w is the shaft power of the air turbine unit under unit working fluid flow rate, w i,c Let η be the shaft power of the compressor under unit working fluid flow rate in the i-th segment. i,c Let w0 be the isentropic efficiency of the compressor, w0 be the design power of a single unit, and η be the isentropic efficiency. sys This refers to the unit's energy conversion efficiency.

[0060] Step 4: Based on the energy conversion efficiency of the unit and the cost of the compressed air energy storage power station, conduct an economic evaluation of the compressed air energy storage power station.

[0061] Cost analysis methods for compressed air energy storage power stations include:

[0062] Step a: Based on the thermal system, perform dynamic balance calculations on the thermal storage system within a single cycle to obtain the thermal storage medium and cooling water consumption;

[0063] Step b: Calculate the volume of the gas storage tank based on the gas consumption within a single cycle;

[0064] Step c: Analyze the cost of the compressed air energy storage power station based on the cooling water consumption and the gas storage capacity.

[0065] Among them, the dynamic balance calculation of the thermal storage system within a single cycle is performed, and the calculation formula is shown in formula (3):

[0066]

[0067] In formula (3), G xurec,i C represents the amount of heat storage medium used at the outlet of the i-th compressor. xure C represents the specific heat capacity of the heat storage medium. air For the specific heat of air at constant pressure, G xuree,i Let be the amount of heat storage medium used at the outlet of the i-th air turbine, where i = 1, 2, 3, 4…k-1.

[0068] The volume of the gas storage facility satisfies the relationship shown in formula (4):

[0069] Vρ(P smin ,T s )+G e t e =Vρ(P smax ,T s (4)

[0070] In formula (4), V is the gas storage volume, and T s P represents the temperature of the gas storage facility. smax P is the highest pressure in the gas storage facility. smin Set T to the minimum pressure of the gas storage facility. s The temperature is 40℃.

[0071] The economic evaluation method for compressed air energy storage power stations provided in this embodiment can evaluate the economic performance of compressed air energy storage power stations based on the energy conversion efficiency of the units and the cost of the compressed air energy storage power stations, making it easier to make reasonable and scientific selections for different installation schemes.

[0072] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0073] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0074] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0076] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for evaluating the economy of a compressed air energy storage power plant, characterized in that, The application relates to a method for setting up a compressed air energy storage power station. The method comprises the following steps: setting up basic parameters of the compressed air energy storage power station and configuring the compressed air energy storage power station; calculating a thermal system of the compressed air energy storage power station according to the configuration; calculating energy conversion efficiency of a unit according to the thermal system; evaluating the economic efficiency of the compressed air energy storage power station according to the energy conversion efficiency of the unit and the cost of the compressed air energy storage power station; （1）； In formula (1), For the first Section compressor, This refers to the compressor stage number. For compressor polytropic index, For the first The inlet pressure of the compressor section. For the first The outlet pressure of the compressor section. For the first The inlet temperature of the compressor section. For the first The outlet temperature of the compressor section. This refers to the high-temperature side temperature of the heat storage medium. The heat transfer at the upper end of the heat exchanger is poor. The air turbine expansion ratio, This is the minimum pressure for the gas storage facility. Atmospheric pressure, The thermal insulation index of an air turbine. For the first The inlet pressure of the air turbine. For the first The outlet pressure of the air turbine. For the first The inlet temperature of the air turbine. For the first The outlet temperature of the air turbine. For the first Shaft power of a section air turbine per unit working fluid flow rate The shaft power of the air turbine unit under unit working fluid flow rate. Design power for a single unit, This refers to the mass flow rate of the compressor unit. For energy storage duration, This refers to the mass flow rate of the air turbine unit. For the duration of energy release, For air turbine efficiency The gas constant of air; the calculation formula of the thermal system is shown in formula (1); （2）； In formula (2), is the shaft power of the air turbine unit per unit mass flow rate of working medium, is the shaft power of the first-stage compressor per unit mass flow rate of working medium, is the shaft power of the second-stage compressor per unit mass flow rate of working medium, is the isentropic efficiency of the compressor, is the design power of a single unit, is the energy conversion efficiency of the unit. the calculation formula of the energy conversion efficiency of the unit is shown in formula (2); the cost analysis method of the compressed air energy storage power station comprises the following steps: calculating the dynamic balance of the heat storage system in a single cycle according to the thermal system to obtain the heat storage medium and the cooling water consumption; calculating the volume of the gas storage according to the gas consumption in a single cycle; analyzing the cost of the compressed air energy storage power station according to the cooling water consumption and the volume of the gas storage; （3）； In equation (3), is the first segment compressor outlet regenerative medium usage, is the regenerative medium specific heat capacity, is the air constant pressure specific heat, is the first segment air turbine outlet regenerative medium usage, where, ; The volume of the gas reservoir satisfies the relationship as shown in equation (4): (4); In equation (4), V is the volume of the gas storage, T is the temperature of the gas storage, Pmax is the maximum pressure of the gas storage, Pmin is the minimum pressure of the gas storage.

2. The compressed air energy storage power plant economy assessment method of claim 1, wherein, the calculation formula of the dynamic balance of the heat storage system in a single cycle is shown in formula (3): setting up basic parameters of the compressed air energy storage power station and configuring the compressed air energy storage power station comprises the following steps: setting up the installed capacity, the energy storage time length and the energy release time length of the compressed air energy storage power station; selecting a gas storage and setting up the pressure fluctuation range of the gas storage; 3. The compressed air energy storage power plant economy evaluation method according to claim 2, characterized in that, configuring the temperature range of the heat storage medium of the compressed air energy storage power station, the heat transfer end difference of the heat storage and exchange system and the resistance loss.

4. The compressed air energy storage power plant economy evaluation method according to claim 2, characterized in that, The energy storage time is selected as valley electricity energy storage, the energy storage time length is set to be 8 hours, and the energy release time length is set to be 4-6 hours. The abandoned salt cave or the artificial chamber is selected as the gas storage, the pressure fluctuation range of the abandoned salt cave is set to be 1.5-2.5 MPa, and the pressure fluctuation range of the artificial chamber is set to be 5-8 MPa.

5. The compressed air energy storage power plant economy assessment method of claim 1, wherein, The inlet temperature of the first compressor is determined by the meteorological condition of the site of the compressor, and the inlet temperature of the rest of the compressors is set to 40℃; the number of air turbine stages is one less than the number of compressor stages, and each air turbine stage is expanded to atmospheric pressure by using the method of equal ratio expansion .

6. The compressed air energy storage power plant economy assessment method of claim 1, wherein, Setting was 40 °C.

Images