Building sofc power supply system economic evaluation method based on multi-specialty bill of quantities

Abstract

The application discloses a kind of based on multi-specialty bill of quantities building SOFC power supply system economy evaluation method, it is related to distributed energy system economy evaluation technical field;The method takes the process, electrical, civil engineering, instrument control multi-specialty bill of quantities of building SOFC power supply project as core input, realizes evaluation by "list parameter analysis→dynamic investment estimation→multivariate financial evaluation→profit boundary determination" four general processes: first, the mapping rule of list and evaluation index is established, and the core parameters are extracted;Then, combined with regional quota and market benchmark price, a dynamic model is constructed to calculate the total investment;Introduce product maturity and operation parameter variable, calculate annual profit through general formula;Finally, the break-even point is determined by single-factor sensitivity analysis to determine the profit potential of the project.

Description

Technical Field

[0001] This invention relates to the field of economic evaluation technology for distributed energy systems, and specifically to an economic evaluation method for building SOFC power supply systems based on multi-disciplinary bill of quantities. Background Technology

[0002] Building-distributed SOFC power supply systems have significant application potential due to their high efficiency and low carbon footprint. However, economic assessment is a core prerequisite for project implementation—accurate calculation of investment and returns is necessary to clarify profit boundaries. Current traditional assessment methods have significant flaws: they rely solely on empirical coefficients (such as cost per unit power) or general financial models for estimation, detaching themselves from multi-disciplinary engineering quantities such as process and civil engineering, failing to differentiate SOFC product maturity, and neglecting to quantify the impact of energy price fluctuations. This leads to large estimation errors and blurred profit boundaries, severely hindering the promotion of SOFC technology. Therefore, a list-driven assessment method that is not tied to specific power outputs and is adaptable to multiple scenarios is urgently needed. Summary of the Invention

[0003] This invention provides a universal method for evaluating the economic viability of SOFC power supply systems in buildings. It does not require specific power or equipment specifications, improves the accuracy of investment estimation through multi-disciplinary list analysis, ensures accurate cost by differentiating product maturity, quantifies energy sensitivity to clarify profit boundaries, and is adaptable to the needs of various SOFC projects in buildings.

[0004] The technical solution of the present invention is as follows: An economic evaluation method for building SOFC power supply systems based on multi-disciplinary bill of quantities is proposed. This method uses the multi-disciplinary bill of quantities of the building SOFC power supply project as the core input and achieves economic evaluation under different scenarios through a four-step general process: "bill of quantities parameter analysis → dynamic investment estimation → multivariate financial evaluation → profit boundary determination". The details are as follows: (1) Multi-professional list analysis: Extract the core evaluation parameters from the SOFC project's process, electrical, and civil engineering lists, and establish a general mapping rule for "list items - evaluation indicators".

[0005] Process Engineering: Extract the core parameters of SOFC units (rated power, power generation efficiency) and process piping specifications, and the corresponding evaluation indicators are "SOFC unit purchase cost" and "process materials and equipment cost"; Electrical and Instrumentation Specialty: Extract the type of power distribution equipment (low-voltage switchgear), cable specifications and laying length, and the corresponding evaluation indicators are "electrical equipment purchase cost" and "cable and installation cost"; Civil engineering: Extract the type of equipment foundation, concrete strength grade and foundation volume, and the corresponding evaluation index is "civil engineering cost"; The specific items and parameters in the list need to be adjusted according to the rated power of SOFC. For example, the higher the power, the larger the cable cross-section and the foundation volume should be.

[0006] (2) Dynamic investment estimation: Based on the analyzed list parameters and combined with the construction engineering quota of the project location, a dynamic calculation model of "work quantity-price-adjustment coefficient" is constructed to calculate the total investment.

[0007] Project cost calculation: The general formula is used: Project cost = Σ (Quantity of a certain specialty in the bill of quantities × Market price of the corresponding materials / equipment for that specialty × Regional adjustment coefficient k) (Note: k is determined based on the price level of the region where the project is located, such as k=1.0-1.2 in the eastern coastal areas and k=0.8-1.0 in the central and western regions; the market price is based on local construction project price information) Other expenses are calculated according to the industry's general proportion rules: Other expenses = Engineering costs × Comprehensive rate (including construction management fees, design fees, etc., recommended 5%-8%, the specific rate is adjusted according to the quota of other construction expenses in the project location).

[0008] Total Investment Calculation: Total Investment = Engineering Costs + Other Costs + Basic Contingency Fund (Recommended: 3%-5% of the sum of engineering costs and other costs) (3) Multivariate financial evaluation: Two types of general variables are introduced to establish a general financial evaluation model that is suitable for different product stages and energy price scenarios of SOFC.

[0009] ①Variable 1: SOFC product maturity Differentiate between "experimental stage products" and "mature stage products," and establish general cost rules: Trial phase: Operation period T1 = 3-5 years, annual maintenance fee F1 is a fixed value (estimated based on unit power P, recommended 50,000-150,000 yuan / year), additional labor costs for dedicated operation and maintenance need to be included; Mature stage: Operating period T2 = 8-12 years, annual maintenance fee F2 = total investment × proportional coefficient (recommended 1%-3%), labor costs can be covered by existing building maintenance personnel (not included or partially included in the cost allocation). ②Variable 2: Energy and operating parameters General parameter dimensions: Annual operating time H (recommended 6000-8000 h, adjusted according to building load continuity); Unit energy price (natural gas price Cg, tap water price Cw, electricity price Ce, all based on the benchmark price of the project location); Energy consumption (natural gas consumption G, tap water consumption W, both calculated based on SOFC unit power P and efficiency η: G=P×H / (η×natural gas calorific value), W estimated based on unit cooling / vaporization requirements); ③ General financial formula Annual direct cost = G×Cg + W×Cw + auxiliary power cost (estimated based on the power of the unit's auxiliary system). Annual indirect costs = annual maintenance and repair costs (F1 / F2) + labor costs + depreciation (based on straight-line depreciation over the operating period, with a recommended residual value rate of 3%-5%) + amortization; Annual income = Annual power generation (P × H × load factor, recommended load factor 0.7-0.9) × Ce; Annual profit = Annual revenue - Annual direct costs - Annual indirect costs.

[0010] (4) Determination of the profit margin Using a general method of single-factor sensitivity analysis, the impact of core variables on annual profit is quantified, and the profit frontier is output: Set one variable as a "variable variable" (such as electricity price Ce or natural gas unit price Cg), and fix other variables as the project's baseline value; Calculate the annual profit corresponding to the variable in different value ranges (e.g., Ce = 0.5-2.4 yuan / kWh, Cg = 0-4 yuan / Nm³); determine the "critical value of the variable" when the annual profit = 0, i.e., the break-even value (e.g., break-even electricity price Ce0, break-even natural gas price Cg0) through linear fitting or interpolation; output the conclusion: when the actual variable value ≥ Ce0 (or ≤ Cg0), the SOFC project has profit potential.

[0011] The design concept of this invention: This method uses the bill of quantities for multiple disciplines (process, electrical, civil engineering, and instrumentation) of SOFC power supply projects in buildings as core inputs. It achieves evaluation through a four-step general process: "bill of quantities parameter analysis → dynamic investment estimation → multivariate financial evaluation → profit boundary determination." First, it establishes mapping rules between the bill of quantities and evaluation indicators, extracting core adaptability parameters. Then, it combines regional quotas and market benchmark prices to construct a dynamic model to calculate the total investment. Next, it introduces product maturity and operational parameter variables, calculating annual profit using a general formula. Finally, it determines the break-even point through single-factor sensitivity analysis, assessing the project's profit potential. This method is not bound to specific power or equipment specifications, making it suitable for various building SOFC projects, improving estimation accuracy and universality, and providing a reliable basis for early-stage project decision-making.

[0012] The beneficial effects of this invention are: 1) Wide adaptability: By adjusting the list parameters, regional coefficients and energy prices, it can adapt to the assessment needs of different regions and different product stages; 2) Logic is universal: It does not depend on the specific usage or price of a single project, and the core model (such as investment estimation formula and profit boundary fitting method) can be directly reused. Detailed Implementation

[0013] The present invention will be further described below with reference to specific embodiments.

[0014] Specific Implementation Example: A 25kW SOFC Power Supply Project in an Office Park in Zhejiang Step 1: Inventory parsing (corresponding to the general mapping rules of Step 1 in the technical solution) Process: 1 set of 25kW SOFC unit, 60 m of DN20 stainless steel pipe, 10 m of DN15 stainless steel pipe; Electrical: 1 low-voltage switchgear, 230m of NG-A-0.6 / 1kV 4×25+1×16mm² cable; Civil engineering: 10.5m³ C30 reinforced concrete independent foundation and 35m² hardened ground.

[0015] Step 2: Investment estimation (corresponding to the general model of step 2 of the technical solution) Project cost = SOFC unit purchase cost + process materials and equipment cost + electrical equipment purchase cost + cable and installation cost + civil engineering cost = 1,971,900 yuan; Other expenses = 1,971,900 yuan × 14.16% (comprehensive fee rate in Zhejiang region, including construction management fee of 6.29% + design fee of 3.86%, etc.) = 279,200 yuan; Basic contingency fund = (197.19 + 27.92) × 5% = 112,600 yuan; Total investment = 197.19 + 27.92 + 11.26 = 236.37 million yuan.

[0016] Step 3: Financial Evaluation (corresponding to the general variable rules for Step 3 of the technical solution) Product maturity: Experimental product (T1=5 years, F1=100,000 yuan / year, labor cost 400,000 yuan / year); Mature product (T2=10 years, F2=236.37×2%=47,300 yuan / year, no labor cost). Energy parameters: H=8000h, Cg=3.9 yuan / Nm³ (G=4.8Nm³ / h), Cw=4.05 yuan / m³ (W=0.015Nm³ / h), Ce=0.76 yuan / kWh (annual power generation = 25×8000×0.8=160,000 kWh); Calculation results: Annual profit of the trial product = -891,300 yuan, annual profit of the mature product = -245,500 yuan.

[0017] Step 4: Profit Margin (corresponding to the general fitting method in Step 4 of the technical solution) Electricity price sensitivity: With Cg = 3.9 yuan / Nm³ fixed, the fitted result shows that the mature product Ce0 = 2.04 yuan / kWh (i.e., profitability is achieved when Ce ≥ 2.04 yuan / kWh).

[0018] Natural gas sensitivity: With a fixed Ce = 0.76 yuan / kWh, the project will incur losses regardless of how much fuel prices decrease.

[0019] This invention is applied to the investment estimation and financial evaluation of solid oxide fuel cell (SOFC) power supply systems in building scenarios. It provides a universal evaluation method that integrates engineering quantity list data from multiple disciplines, including process, electrical, and civil engineering, and is adaptable to different maturity stages of SOFC products. It can quantify energy price-sensitive factors and is applicable to the early decision-making, investment feasibility analysis, and operating income forecasting of SOFC projects of various power scales in buildings.

Claims

1. An economic evaluation method for building SOFC power supply systems based on multi-disciplinary bill of quantities, characterized in that, Includes the following steps: Step 1) Analyze the bill of quantities for the SOFC project, which includes multiple disciplines such as process, electrical, and civil engineering, extract core parameters, and establish a mapping relationship between bill of quantities items and evaluation indicators; The core parameters include the rated power of the SOFC unit, the specifications of the process piping, the type of power distribution equipment, and the basic parameters of the equipment. Specific items are adjusted according to the rated power of the SOFC. Step 2) Based on the parsed list and the construction engineering quota of the project location, calculate the project cost through the model, calculate other costs in combination with the comprehensive rate, and calculate the total project investment after adding the basic contingency reserve; Among them, the project cost = project quantity × market price × regional adjustment coefficient; Other expenses = Project costs × Comprehensive rate; Total investment = project cost + other costs + basic contingency fund; Step 3) Introduce SOFC product maturity variables and energy price variables to calculate annual profit: The SOFC product maturity variables include: Trial phase: 3-5 years of operation, fixed annual maintenance fee; Mature stage: 8-12 years of operation; annual maintenance fee = total investment × proportional coefficient. Energy price variables include annual operating time H, unit energy price, and energy consumption; Annual profit = Annual revenue - Annual costs; Annual cost = Direct cost + Indirect cost; Annual income = Annual electricity generation × Electricity price; Step 4) Through single-factor sensitivity analysis, the break-even electricity price and break-even natural gas price when the annual profit is 0 are fitted to determine the profit potential of the SOFC project.

2. The economic evaluation method for building SOFC power supply systems based on multi-disciplinary bill of quantities as described in claim 1, characterized in that, The regional adjustment coefficient mentioned in step 2) is determined based on the price level of the project location, ranging from 0.8 to 1.2; the comprehensive fee rate is 5%-8% of the project cost, specifically determined according to the quota of other construction costs in the project location.

3. The economic evaluation method for building SOFC power supply systems based on multi-disciplinary bill of quantities as described in claim 1, characterized in that, In step 3), the annual power generation is calculated as: SOFC unit rated power × annual operating time × load factor. The annual operating time ranges from 6000 to 8000 hours, and the load factor ranges from 0.7 to 0.

9.

4. The economic evaluation method for building SOFC power supply systems based on multi-disciplinary bill of quantities as described in claim 1, characterized in that, The single-factor sensitivity analysis described in step 4) calculates the break-even value through linear fitting or interpolation. The break-even value is the critical point of the function of annual profit and the variable.

5. An economic evaluation system for implementing the method of any one of claims 1-4, characterized in that, It includes a list parsing module, an investment estimation module, a financial evaluation module, and a boundary determination module. The bill of quantities parsing module: It performs structured decomposition of the bill of quantities for multiple disciplines such as process, electrical, and civil engineering in SOFC projects, extracts core parameters and establishes a dynamic mapping with evaluation indicators, providing standardized basic data for subsequent analysis; Investment estimation module: Based on the analysis list and regional construction quotas, through itemized accounting, comprehensive cost calculation and contingency fund addition, it accurately quantifies the total investment of the project and analyzes the cost composition. Financial evaluation module: Introduces product maturity and energy price variables to calculate the annual income and expenditure and profit of the project at different stages, diagnose the current profitability status and identify the core influencing factors; Boundary determination module: Through single-factor sensitivity analysis, it fits the break-even electricity price and natural gas price thresholds to clarify the project's profit range and potential, providing a quantitative basis for decision-making; Each module supports custom parameter input, adapting to SOFC projects in buildings with different regions and power levels.