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- Abstract：The research progress of numerical simulation of parabolic trough solar collector was introduced. Especially the numerical simulation studies of the internal flow field in the collector tube and the external flow field of the concentrator were reviewed. In the study of the internal flow field in the collector tube, the type of heat transfer fluids and the characteristics of optical concentration have a significant effect on the heat collection performance and thermal stress distribution, especially in the water/steam medium heat collection loop. The unique gas-liquid two-phase flow superposition of the non-uniform heat flux distribution outside the tube may lead to serious thermal stress bending deformation of the collector tube. In the study of the external flow field of the concentrator, due to the high actual wind speed and the low structural strength of the ultra-thin lens, the concentrator is subjected to wind load deformation, resulting in the loss of optical efficiency, and even leading to the failure of the parabolic trough collector structure, which directly affects the normal operation of the whole collector field.Keywords：carbon neutrality;solar-thermal technology;parabolic trough collector;internal flow field;external flow field;numerical simulation26|6|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：The integration of renewable energy combined heat and power system has broad application prospects in the field of regional comprehensive energy utilization. This paper proposed a parabolic trough solar-assisted biomass-fired cogeneration system. The system uses medium and low temperature trough solar energy to heat the thermal oil that drives the absorption heat pump to preheat the supply-water, while the biomass fuel and heat output keep constant. The extraction steam for heating is decreased while power generation is increased. The EBSILON professional software was used to model and simulate the case plant and integrated system, and on this basis, the thermodynamic characteristics of energy flow and exergy loss of the system were analyzed. The results show that, under the design conditions, 1.78 MW·h of solar power can be generated, the solar-to-electricity efficiency is 20.06%, and the solar-to-electricity exergy efficiency can reach 21.60%. Five typical days were selected to explore the performance under different radiation conditions. We found that the solar radiation and system performance on March 21st are both the best. A time-by-hour simulation analysis was conducted for the entire heating season. A total of 1 124.30 MW·h of solar power is produced in the five-month heating period with an average solar-to-electricity efficiency of 16.49%.Keywords：trough solar energy;biomass-fired cogeneration;absorption heat pump;system integration;thermodynamic analysis48|4|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：The parabolic trough solar collector is a commercialized and mature concentrating solar collector, which is widely used in the field of medium temperature solar industrial heat utilization and high temperature solar thermal power generation. However, the inherent drawback of solar energy is contrary to the stable and continuous operations expected by the energy supply system. Usually, adjusting the flow rate of the heat transfer fluid is a method to let the collector provide a relatively stable output under varying solar irradiation conditions, which plays a key role in the stability of its downstream equipments. In order to clarify how the change of flow rate affects the transient thermal behaviors of the collectors, this study carried out experiments with the step-change of the flow rate by the manual adjustment, and then carried out the analysis of Reynolds number, Nusselt number and the convective heat transfer coefficient of the heat transfer fluid with different flow rates.Keywords：solar thermal power generation;carbon peak;carbon neutrality;greenhouse gas emission;parabolic trough solar collector;heat transfer characteristics;convective heat transfer coefficient27|4|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：The solar radiation is intermittent and unstable, and its dynamic instability affects the stable output of parabolic trough solar collector. Therefore, it is extremely important to study the dynamic characteristics of the solar heating process of parabolic trough solar collector. The dynamic simulation model of parabolic trough solar collector one-dimensional loop was constructed based on the Simscape environment in MATLAB/Simulink software. Based on the verified dynamic simulation model, the influence of mass flow and direct normal irradiance on the outlet temperature of the loop of parabolic trough solar collector was obtained. According to the obtained law, the dynamic regulation model of the loop of parabolic trough solar collector was constructed based on the proportional integral. The results show that the control strategy can make the outlet temperature of the loop reach the set temperature of 395 ℃ within 2 500 s when the direct normal irradiance increases suddenly, and maintain the output temperature fluctuation within -2 ℃ to 2 ℃ when the direct normal irradiance decreases suddenly. Based on the dynamic regulation strategy, the operation of the loop of parabolic trough solar collector in typical day was simulated. The results show that the regulation strategy can maintain the outlet temperature of the loop in the operation time and the thermal efficiency close to the ideal value. The study provides a new method for the construction of dynamic model of the parabolic trough solar collector, and the results can provide reference for the dynamic operation of the parabolic trough solar field.Keywords：solar thermal power generation;parabolic trough solar collector;dynamic simulation model21|4|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：To explore the influence of heat transfer fluids on the heat transfer characteristics of solar receivers, the heat transfer characteristics of conical cavity receivers with supercritical CO2 and compressed air as heat transfer fluids were compared and analysed by combining ray tracing and computational fluid dynamics method. Based on numerical simulation, the effects of cone angle, fluid inlet mass flow rate and inlet temperature on heat transfer performance of receivers were discussed. The results show that under the same working conditions, the outlet temperature of compressed air is higher than that of supercritical CO2, but the corresponding receiver thermal efficiency and system photothermal conversion efficiency are lower. For the two heat transfer fluids, the system photothermal conversion efficiencies reach the optimal values with the cone angle of 4.12°. In the range of operating parameters studied, the outlet temperature of heat transfer fluids increase linearly with the increase of inlet temperature. Once the mass flow rate exceeds 0.04 kg/s, increasing the mass flow rate has little effect on improving the photothermal conversion efficiency of the system.Keywords：solar energy;receiver;supercritical CO2;compressed air;heat transfer characteristics59|5|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：Three tower heliostat field layouts, EB, No blocking-dense, and DELSOL derived from the radial staggered layout and the principle of no blocking loss, were studied. After summarizing the mathematical models of the three heliostat field layouts, combined with some design parameters of Gemasolar power tower plant, the software SolarPILOT was used to model and simulate the heliostat field according to the three layout modes. MATLAB was used to process the coordinate data of the heliostat field obtained by the modeling, and the change curves of radial spacing and azimuth spacing were obtained, so as to verify the rationality of the three layout mathematical models. The layout rules of the heliostat ring were obtained by analyzing the arrangement characteristics of the basic ring and the staggered ring in each heliostat field. At the same time, the performance of different layouts was compared from the number of heliostats, the optical efficiency, the land utilization ratio and the receiving energy of the heliostat field, and their advantages and disadvantages were analyzed. The results show that in the range of 1 000 m radius of the heliostat field, the average annual optical efficiency and land utilization rate of the heliostat field under the No blocking-dense layout are the highest, followed by the EB layout. However, the number of the heliostats and the receiving energy of the heliostat field under the EB layout are the largest, and the performance characteristics of the DELSOL layout are the lowest.Keywords：solar thermal power generation;solar power tower plant;heliostat field layout;radial spacing;azimuth spacing83|9|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：The absorber tubes are subjected to highly non-uniform solar irradiation inside a water/steam solar cavity receiver. This causes the uneven wall temperature and large gradients applied to the absorber tubes, producing thermal deformation and stress, even the damage and failure of the receiver. The typical boiling tube and superheated tube were selected as the research objects. The thermal-structural coupling numerical simulation was carried out by using ANSYS finite element analysis method. The results show that these two types of tubes have significant differences in terms of heat transfer. The radial temperature gradient of the boiling tube leads to the bi-axial thermal stress appearing on the inner and outer walls of its irradiated front side. The circumferential temperature gradient of the superheated tube results in the serious bending deformation and the high axial stress, which also induces the circumferential distribution of equivalent stress. When the concealed back side of the absorber tubes is constrained by supports, the tube bending is significantly improved, and the thermal stress of the superheated tube is no longer circumferential. Furthermore, the axial normal stress component increases greatly and the equivalent stress on the absorber tubes increases by 1.3-6.9 times.Keywords：solar receiver;boiling tube;superheated tube;temperature gradient;thermal stress;support constraint33|6|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：As the key equipment of the tower thermal power station, the safe and efficient operation of the receiver has an important impact on the reliability and economy of the power station. The receiver is installed on the top of the tower, and the environmental meteorological factors, especially the wind speed, are directly related to the operation control strategy of the receiver and the concentrating system. Based on this, this paper used numerical simulation method to study the wind speed characteristics of the high-altitude tower receiver in different directions. The trend of wind speed on the surface of the tube panel changing with the environmental wind speed and direction was obtained. In addition, the wind speed calculation correlation was fitted and the calculation wind direction was agreed in detail. This work has important guiding significance for the accurate calculation of heat loss, the accurate evaluation of efficiency and the safe and reliable operation of the receiver.Keywords：solar thermal power generation;receiver;wind speed characteristics;fitting correlation37|4|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：As a kind of green and clean energy, solar energy plays a significant role in green development. To use the solar energy efficiently, a solar collector with an inner-cooling vapor chamber was designed and manufactured. The solar collector consists of the inner-cooling vapor chamber which is used as the receiver, and the multi-stage concentrator which is combined the line-focus Fresnel lens (LFL) and the compound parabolic concentrator (CPC). In addition, the designing method of the compound parabolic concentrator was proposed, its accuracy and the reliability of the solar collector were verified through the optical simulation and experiments. The results of optical simulations and experiments show that the compound parabolic concentrator manufactured according to the designing method proposed in this paper can concentrate the sunlight efficiently, with an optical efficiency of 78.42%. In the experiments where the solar collector is sealed with a transparent plastic cover, the inner-cooling vapor chamber solar collector can efficiently absorb the radiated solar energy and the air heat in the greenhouse with a high thermal efficiency of 98.94%.Keywords：inner-cooling vapor chamber;solar collector;liner-focus Fresnel lens;compound parabolic concentrator49|16|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：Molten salt has important applications in renewable energy power generation and energy storage heating system as the heat transfer and storage working fluid. As the constant power heating can easily lead to the burning of electric heater and the decomposition of molten salt, a constant temperature electric heating system is needed for melting and anti-freezing of molten salt system. We used monitor and control generated system (MCGS) configuration software and SIEMENS S7-200PLC, combined with solid-state relay (SSR), thermal resistance and electric heater, to design a closed-loop electric heater temperature PI control system. According to different PI tuning methods for experimental comparison, the contradiction problems of the PI controller over-tuning and anti-interference were solved by adding anti-integral saturation and two-degrees-of-freedom control. While the over-tuning was greatly reduced, the anti-interference function of the temperature of molten salt heat storage system under the interference condition was realized, and the temperature control of molten salt heat storage electric heater was carried out.Keywords：solar energy utilization;heat storage of molten salt;monitor and control generated system (MCGS);programmable logic controller (PLC);temperature control;PI control31|3|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
Solar Thermal Power Generation Technology
- Abstract：The new integrated energy system is one of the best application scenarios to carry out multi-energy supply and utilization under the background of low carbon economy, which has important enlightenment significance to promote the optimization and adjustment of China's energy structure. Taking a distributed power station in Guangzhou as the research object, this paper described the basic characteristics, system composition and key technologies of the integrated energy system of multi-energy combined power supply. The system was based on the traditional combined cold, heat and power supply, and provided diversified energy services such as compressed air, photovoltaic/energy storage, electricity sales, contracted energy management, green traffic charging, and equipment maintenance and so on. The integrated energy service covered the whole industrial park and radiated to the surrounding areas, forming a smart, efficient, clean and low-carbon integrated energy service system. The research results provide new ideas and important references for the exploration of new integrated energy system services.Keywords：integrated energy system (IES);multi-power combined supply;multi-energy collaborative supply;clean and low-carbon57|4|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：With the rapid development of China's power industry, the power grid structure tends to be complicated. In order to further optimize the grid structure, through the analysis of the actual grid, this paper proposed that the power grid had two functional attributes of hydropower transmission and load center. According to the characteristics of different functional attributes, a regional power grid planning method was proposed, which considered economy, hydropower transmission and load center functional attributes. It included objective functions and related constraints such as line construction cost, line operation cost, hydropower transmission profit, system blocking coefficient, and short-circuit current penalty function. MATLAB and PSD-BPA joint simulation method were used to analyze a regional power grid with high-attributed hydropower transmission and medium-attributed load center. The results show that the grid structure index of the optimization model considering the functional attribute is better, which can effectively promote the consumption of hydropower transmission and reduce the short-circuit current level of the load center.Keywords：power grid planning;functional property;hydropower transmission;load center44|5|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：The impact of climate change on human society has attracted more and more attention, and the risk of power outage caused by a series of extreme weather is becoming more and more significant. In order to deal with climate change, especially extreme weather, human society needs to adopt two coping strategies of mitigation and adaptation. For the developing countries and small island countries, since climate change has already taken place, the climate problem will first be adaptation. In order to solve the problem of how the power system can fully adapt to climate change from all aspects, a power system development system adapted to climate change was established, and a construction method of power system development path covering extreme meteorological factors was proposed. On the basis of summarizing the impacts of various extreme weather on the power system, the vulnerability of power grid was evaluated. The overall strategy of adapting to extreme weather was studied, and the scheme of power system adapting to extreme weather events was proposed, namely planning-construction-emergency management-assessment (PCEA) disaster resistance system. In the planning stage, the study focused on the minimum power grid planning and built the minimum power grid backbone network without power outage. Based on the application examples in different stages of the scheme, it was verified that the PCEA system can make the power system better adapt to the extreme weather.Keywords：power system;climate change;extreme weather;minimum power grid planning;minimum power grid backbone network without power outage108|4|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
- Abstract：Taking photovoltaic array power generation, lithium battery energy storage, DC load and grid-side converter as the research objects, the whole system was divided into 6 working modes, and the coordinated control strategy of the microgrid was studied through the conversion operation of different working modes. The lithium battery was divided into two groups. In order to improve the efficiency of the battery and the whole system and optimize the working characteristics of the battery, the idea of energy balance was introduced, and the energy balance algorithm was combined with the droop control based on the state of charge value, which helped to achieve power balance of two groups of lithium batteries. The simulation model of the system was built using Matlab/Simulink software. The change of system operation was realized by changing the size of load power. The simulation results show that the DC bus voltage keeps constant, the power balance of the entire system is realized, and the feasibility of the coordinated control strategy of the system is verified.Keywords：DC microgrid;coordinated control;energy balance;droop control30|5|0<HTML><DownloadPDF> <Meta-XML>Updated：2025-07-04
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