Wave energy resources, particularly the incident wave power density, are critical to the design and evaluation of wave energy conversion systems. Based on the operational principles of the Eagle wave energy converter, this study analyzes the incident wave power density under realsea conditions, develops a methodology for measuring input wave energy power, and establishes an input wave power model. Utilizing wave data including significant wave height, mean period, and wave direction collected over 217 consecutive hours from June 8 to 18, 2016, during the realsea state testing of the "Wanshan" Eagle wave energy converter, the realtime input wave energy power was measured and compared with published literature data. The results indicate that the measured values are generally lower than those reported in the literature, and the temporal variation in wave power is more gradual, providing a more accurate representation of actual marine environmental changes. Consequently, the proposed incident wave power measurement method can offer precise and reliable reference data for the design and performance assessment of wave energy conversion systems or wave power stations.

Pretreatment and enzymatic hydrolysis of straw type biomass are among the key technologies for its high value conversion and utilization. Using corn stover as the raw material, pretreatment methods with formic acid, sodium chlorite, and alkaline hydrogen peroxide were studied and compared. Methods such as scanning electron microscopy, Xray diffraction, and Fouriertransform infrared spectroscopy were employed to analyze the composition, morphology, crystal structure, and functional groups of corn straw before and after pretreatment. After pretreatment with formic acid, sodium chlorite, and alkaline hydrogen peroxide, the lignin removal rates were 66.71%, 97.12%, and 91.88% respectively, and the enzymatic hydrolysis rates reached 63.26%, 71.83%, and 95.14% respectively. Under the conditions where the cellulase dosage is 19.6 FPU/g, the xylanase dosage is 35.44 IU/g, and the Tween 80 dosage is 20.96 mg/g, the predicted enzymatic hydrolysis rate of corn straw pretreated with alkaline hydrogen peroxide is 95.57%, while the actual enzymatic hydrolysis rate is 94.42%. The optimal feeding strategy for high solid enzymatic hydrolysis was an initial substrate concentration of 8%, with 4% of the substrate added at 6, 12 h, and 24 h respectively. After 120 h of enzymatic hydrolysis, the enzymatic hydrolysis rate reached 87.57%.

The low energy consumption and mild storage and transportation conditions of the clathratebased solid natural gas technology make it a key factor in promoting the development of the natural gas industry. However, the slow hydrate formation kinetics has hindered its application. This article explores the formation laws of methane hydrates supported by porous media (activated carbon and quartz sand) under the action of 1,3dioxolane. It analyzes the hydration efficiency in different systems, evaluates the synergistic and antagonistic effects of 1,3dioxolane and porous media on hydrate growth, and clarifies the influence of the pore structure. The results show that: under high pressure, the adsorption of 1,3dioxolane by the pore structure of activated carbon leads to an antagonistic effect between the two, resulting in poor hydration efficiency. Moreover, as the initial pressure and the concentration of 1,3dioxolane increase, the antagonistic effect intensifies. Under low pressure, there is a synergistic effect between 1,3dioxolane and activated carbon. The hydration efficiency is affected by pressure. The free 1,3dioxolane enhances the formation of methane hydrates and increases the gas storage capacity of hydrates. 1,3Dioxolane enhances the formation of hydrates in the quartz sand system. However, the rapidly growing hydrates limit the conversion of internal water, making this enhancement effect achieve the best performance when the initial pressure is 5 MPa.

This paper takes GE 9HA.02 combined cycle unit as the research object, and innovatively proposes the design scheme of a hydrogen natural gas mixing integrated system in gas turbine power plant, with gas hydrogen long tube trailers as the main hydrogen transmission method and reserved pipeline gas inlet interface. Through the configuration of a hydrogen compressor bypass system, the residual hydrogen stored in the long tube trailer was fully utilized, improving the utilization rate of trailer hydrogen storage. At the same time, a comparative analysis was conducted on the economic feasibility of adding hydrogen to the 9H class gas turbine power plant. Electricity price and natural gas price are more sensitive to the impact on the internal earing rate of return. And in order to meet the requirements, hydrogen price cannot exceed 38.5 yuan/kg. With the development of renewable hydrogen production technology, and driving the further reduction of hydrogen production costs, the promotion and application of hydrogennatural gas mixing integrated system will become increasingly competitive.

The study elucidated the relationship between anaerobic digestion gas production efficiency and temperature and hydraulic retention time (HRT) using synthetic glucose wastewater as a substrate. Gas production under different temperatures (37,55 °C) and HRTs (25, 30, 50 d) was compared. The results indicated that the hydrolysis rate of glucose was higher at thermophilic temperature than at mesophilic temperature. However, volatile fatty acids, especially propionic acid, tended to accumulate at thermophilic temperature. Additionally, Methanomicrobiaes and Methanosarcinales were enriched at both moderate and high temperatures, suggesting the presence of pathways for methane production from acetic acid and acetate oxidation at both temperatures, with the acetate oxidation pathway exhibiting greater environmental resilience. The recommended optimal fermentation conditions for treating heavy glucosecontaining wastewater through anaerobic digestion are 37 °C and an HRT of 30 days.

In order to comprehensively evaluate the power generation performance of solar cells, aiming at solving the problem that the existing photovoltaic (PV) equivalent circuit model cannot estimate its spectral response characteristics, in this paper, an equivalent physical model of solar cells and its parameter identification method based on the finite element method is proposed to estimate its electrical characteristics and spectral response. Firstly, the influence of key parameters in the finite element model on the estimation results of electrical characteristics is analyzed. Six parameters, including the thickness of the emitter region, the thickness of the base region, the doping concentration of the emitter region, the doping concentration of the base region, the series resistance, and the parallel resistance, are determined as the model parameter identification objects. Then, based on the measured currentvoltage (IV) characteristic data under high irradiation conditions, the particle swarm optimization algorithm is used to identify the above parameters. Finally, the IV characteristics under different irradiation and temperature conditions are measured and compared with the model estimation results. Meanwhile, the solar spectrum curves are measured to indirectly verify the accuracy of the spectral response of the solar cell estimated by the model. The experimental results show that the root mean square error (RMSE) of the estimated current for monoSi and polySi cell models are in the range of 0.019 2 A to 0.030 2 A and 0.018 0 A to 0.051 5 A, respectively. The absolute percentage error between the estimated shortcircuit current and the measured shortcircuit current is concentrated below 15%. The proposed equivalent physical model of solar cell and corresponding parameter identification method can comprehensively reflect its actual performance.

Due to the selection of solar radiation spectrum by solar cells in semi transparent photovoltaic windows, the energy consumption, indoor daylight and thermal environment of photovoltaic window buildings are different with clear glass window buildings. When semitransparent photovoltaic windows are applied to building, specific design values for thermal parameters are required for reference, but there is a lack of basis. Therefore, this paper took an office building in Taiyuan as an example, established a reference building model and a design building model, and explored the influence of the Heat Transfer Coefficient (Uvalue) and Solar Heat Gain Coefficient (SHGC) on the energy consumption of semi transparent photovoltaic window buildings. The recommended range of Uvalue and SHGC value of photovoltaic window is obtained by the method of tradeoff judgment. The results show that smaller Uvalue and larger SHGC value are more beneficial to energy saving when photovoltaic windows are used in Taiyuan. When the windowwall ratio of photovoltaic window building is greater than 0.60 and the transmittance is equal to 0.46, the maximum Uvalue limit is 1.9 times the existing energysaving standard limit. By comparing the recommended range of SHGC value with different window wall ratio, the lower limit of SHGC decreases by 25%.

Steam methane reforming membrane reactor removes hydrogen through a hydrogen selective permeation membrane, which can promote the forward movement of the reaction, improve methane conversion rate with reduced reaction temperature, and achieve thermochemical storage under mediumtemperature of trough solar collector. However, the characteristics of multiphysical field coupling in the reactor are complex, and the influence of operating parameters on the performance of the reactor needs to be further investigated. The steam methane steam reforming reaction in the membrane reactor driven by solar at mid temperature was taken as the research object in this paper. The multiphysics coupling model of fluid flow, heat/mass transfer and chemical reactions in the reactor was established by using ANSYS FLUENT, and the effects of the key operating parameters (i.e., inlet mass flow rate, temperature, reaction pressure, water to carbon ratio and permeation pressure) on the reactor chemical and thermodynamic performances were studied. The results show that the methane conversion rate and energy efficiency are negatively correlated with the inlet flow rate. The conversion rate of methane is positively correlated with reaction temperature. The energy efficiency first increases and then decreases with the increase of temperature, existing a peak value. When the inlet flow rate is low, the methane conversion rate and energy efficiency increase with the increase of the reaction pressure, while the methane conversion rate and energy efficiency decrease with the increase of reaction pressure when the inlet flow rate is high. The increase of the water to carbon ratio can significantly improve the chemical reaction performance but reduce the energy efficiency. The lower the pressure on the permeation side, the better the reactor performance. The research results are of great significance for highgrade solar thermal utilization.

This paper intends to design a deep water spiral pile jacket foundation structure for offshore wind power, and use finite element analysis to simulate the load of wind, wave, current, wind turbine, and the bearing capacity and stability of the foundation structure under the conditions of silt and silty soil, and provide a feasible reference for the design of the finite element model of pilesoil interaction of spiral pile structure. This paper also designs a common pile control foundation model without helical blade structure by means of lateral comparison, and explores the influence of single helical blade on the bearing capacity and stability of the foundation structure. The research shows that the addition of singlelayer helical twist blade structure can significantly improve the bearing capacity and stability of offshore wind power pile foundation structure, and has little influence on the natural vibration frequency under the constraint state of the foundation structure. The relevant data can provide suggestions and references for the design of helical pile foundation in practical engineering.

With the depletion of resources in flat terrain, the site selection for wind farms is gradually shifting towards complex terrains. Complex terrain presents geographical conditions distinct from flat terrain, the undulating topography leads to intricate flow patterns, and the wind characteristics in complex terrains are also different. Therefore, studying the distribution patterns of flow fields in complex terrain is significant for micrositing of wind farms and wind power prediction. This paper, based on the opensource software OpenFOAM, establishes geometric and numerical simulation models for complex terrain. It investigates and analyzes grids, boundary conditions, and turbulence models suitable for complex terrain. The reliability of the numerical model for complex terrain is compared and analyzed using real measurement data from the Askervein mountain. The paper solves the flow field distribution for typical complex terrains such as isolated peaks, plateaus, and peak clusters, studying the impact of slope and height on the flow fields in different terrains. The research reveals that different terrains satisfy the Reynolds number independence principle. In isolated peak topography, the influence of slope becomes more pronounced in the lee zone behind the mountain as the slope increases. Plateau terrain is more affected by changes in height. For peak cluster topography, the flow field development remains consistent under varying slopes and heights, with height having a greater impact compared to slope. The provided distribution ranges of flow field characteristic values in this paper can serve as a reference for wind farm micrositing and wind power prediction in complex terrain.