• Energy Research

Abstract This paper presents the results of a thermo-economic analysis of integrating linear Fresnel reflector (LFR) with cooling, heat and power tri-generation plan (LFR-GTPP). The annual performance of the LFR-GTPP with different sizes of gas turbine and solar collector’s area have been examined and presented. Thermoflex + PEACE software were used for the economic-thermodynamic-environmental assessment of different integration configurations. For the considered tri-generation plant (produce 35.6 kg/s of steam (120.55 MW), 2500 kg/s of chilled water (24440 tons), and 90 MWe of steam turbines electricity), the study revealed that LFR-GTPP with gas turbine sizes in the range 130–190 MWe have more economic feasibility for integrating LFR. Furthermore, the study revealed that the integration of LFR system with a conventional gas turbine tri-generation power plant (GTPP) in locations with high solar radiation has more economic feasibility (with 7.6% reduction in LEC) compared to equivalent GTPP integrated with CO2 capturing technology while achieving the same CO2 emissions reduction. Moreover, a conceptual procedure to determine the optimal configurations of the LFR-GTPP has been developed and presented in this article. The results indicate that the proper location to apply optimal integration configuration is in regions with high levels of solar radiation and low ambient temperature.

Abstract Solar heating (SH) and radiative cooling (RC) have been regarded as promising clean techniques for thermal energy harvesting and temperature control. However, SH and RC are only a single function of heat collection and dissipation, which means the static device of SH and RC cannot meet the dynamic heat requirement of real-world applications, especially in the daytime. Here, a strategy of dynamic integration of SH and RC is proposed for tunable thermal management. A device (i.e., SH/RC device) that includes a silica cavity, ultrapure single-walled carbon nanotubes (SWCNTs) aqueous dispersion, solar reflective film, and deionized water is designed and fabricated. The outdoor experimental results show that the SH/RC device with SWCNTs media can effectively achieve heat collection with a maximum temperature of 78.9°C, while the SH/RC device with deionized water can achieve heat dissipation. Besides, the temperature modulation ability of the SH/RC device is tested to be 26.3°C and can be theoretically improved to be 60.3°C by improving the solar absorptivity (i.e., 0.9 for SH mode and 0.1 for RC mode) regulation ability of the device and improving its thermal emissivity (i.e., 0.9). Furthermore, annual analysis indicates that the cumulative time in which the SH/RC device temperature is in a comfortable region (i.e., 20°C-26°C) for humans is 60.9% and 30.3% higher than that of the device with individual SH and RC mode. In summary, this work provides alternative thinking for tunable thermal management based on the dynamic utilization of the hot sun and cold universe.

AbstractThe present work provides an investigation of the technical and economic feasibility of integrating Concentrating Solar Power (CSP) technologies with cogeneration gas turbine systems that are progressively being installed in Saudi Arabia. Different designs of hybrid solar/fossil fuel gas turbine cogeneration systems have been proposed. These designs consider the possible integration of Solar Tower (ST), Parabolic Trough Collector (PTC), and Linear Fresnel Reflector (LFR) systems with conventional gas turbine cogeneration systems. These three CSP technologies were assessed for possible integration with a gas turbine cogeneration system that generates steam at a constant flow rate of 81.44kg/s at P = 45.88 (bar) and temperature of T = 394°C throughout the year in addition to the generation of electricity. THERMOFLEX with PEACE simulation software has been used to assess the performance of the integrated solar gas turbine cogeneration plant (ISGCP) for different gas turbine sizes under Dhahran weather conditions. Thermo-economic comparative analysis have been conducted to reach the optimal levelized electricity cost (LEC) and CO2 emission combination for each ISGCP configuration for each the three CSP technologies in comparison with the integration of CO2 capture technology to the conventional plant. The simulation results revealed that the optimal configuration is the integration of LFR with the steam side of a gas turbine cogeneration plant of 50 MWe, which gives a LEC of 5.1 US / kWh with 119 k tonne reduction of the annual CO2 emission.

The main criteria to assess a new solar thermal power plant are its performance and cost. Therefore, there is a need to present to the open literature a detailed modeling procedure and cost analyses to help researchers, engineers, and decision makers. The main objectives of this work are to develop a code and to evaluate the optical and thermal efficiencies of parabolic trough collectors (PTCs) solar field considering average hourly, daily, monthly, or annually averaged weather data; in addition to detailed cost analysis of the solar field. In this regard, a computer simulation code was developed using Engineering Equations Solver (EES). This simulation code was validated against Thermoflex code and data previously published in the public literature, and excellent agreements ware observed. The types of the PTC considered in the simulation are EuroTrough solar collector (ET-100) and for LUZ solar collector LS-3. The present study revealed that the maximum optical efficiency that can be reached in Dhahran is 73.5%, whereas the minimum optical efficiency is 61%. This study showed also that the specific cost for a PTC field per unit aperture area and the specific cost of different mechanical works can be cut by about 46% and 48% at 10 hectare and by about 72% and 75% at 160 hectare, respectively, compared to that at 2.8 hectare. On the other hand, the specific civil costs remain constant independent of the plant size. It was found that the ratio of the cost of the PTC to the solar field area decreases significantly as the solar field size increases. This decrement is very significant until the solar field size reaches 60 hectare and then the slope of the decrement is becoming insignificant. Therefore, it is recommended to have a solar field size of 60 hectare or larger.

Abstract In this study, a new hybrid solar preheating intercooled gas turbine (SP-IcGT), is presented, in which a parabolic trough solar technology is used to preheat the compressed air before entering the combustor. The performance of the new hybrid gas turbine was evaluated and compared with the conventional hybrid solar preheating gas turbine (SP-GT). Several performance indicators were used in the analysis under Guangzhou (China) weather data. It is observed that the SP-IcGT is superior to the SP-GT system as it can boost the fuel-based efficiency by 19.35% versus 0.26% for the SP-GT system. In addition, the SP-IcGT has a much lower specific fuel consumption (about 7017 kJ/kWh) compared with the 10362 kJ/kWh for SP-GT. The highest fuel-based efficiency of 51.4% is obtained for the SP-IcGT with 47.4% improvement over the SP-GT, which exhibits a levelized electricity cost of 4.58 US/kWh. Meanwhile, fuel consumption and greenhouse gas emissions can be reduced greatly by integrating solar energy with the intercooled gas turbine. The SP-IcGT is more economical than applying carbon capture to the equivalent conventional gas turbine plant combined while achieving the same reduction of CO2 emissions. Overall, the SP-IcGT is an attractive system under different climates.

An innovative solar thermal power generation system using cascade steam-organic Rankine cycle (SORC) and two-stage accumulators has recently been proposed. This system offers a significantly higher heat storage capacity than conventional direct steam generation (DSG) solar power plants. The steam condensation temperature (

Abstract This article presents the results of a thermodynamic-economic-environmental analysis of integrating linear Fresnel reflector (LFR) with a tri-generation system. The optimal integrated solar field size has been identified and the pertinent reduction in CO2 emissions due to solar integration is estimated. For the considered tri-generation plant (that is required to produce 110 MWe of electricity from steam turbines, 45461 m3/day of freshwater and 2300 kg/s of chilled water), the study revealed that the optimal configuration is the integration of 83.6 hectares of LFR solar field with the tri-generation plant of 130 MWe, which gives a levelized electricity cost of 6.37 USȻ/kWh with 96.40 k-tonne reduction of the annual CO2 emission. The study also revealed that the integration of LFR technology with a conventional tri-generation system (TGS) in high insolation regions has more economic feasibility compared to equivalent TGS integrated with CO2 capturing technology while achieving the same emissions reduction result.

Abstract Solar energy is an abundant resource in many countries in the Sunbelt, especially in the middle east, countries, where recent expansion in the utilization of natural gas for electricity generation has created a significant base for introducing integrated solar‐natural gas power plants (ISGPP) as an optimal solution for electricity generation in these countries. ISGPP reduces the need for thermal energy storage in traditional concentrated solar thermal plants and results in dispatchable power on demand at lower cost than stand-alone concentrated thermal power and much cheaper than photovoltaic plants. Moreover, integrating concentrated solar power (CSP) with conventional fossil fuel based thermal power plants is quite suitable for large-scale central electric power generation plants and it can be implemented in the design of new installed plants or during retrofitting of existing plants. The main objective of the present work is to investigate the possible modifications of an existing gas turbine cogeneration plant, which has a gas turbine of 150 MWe electricity generation capacity and produces steam at a rate of 81.4 at 394 °C and 45.88 bars for an industrial process, via integrating it with concentrated solar power system. In this regard, many simulations have been carried out using Thermoflow software to explore the thermo-economic performance of the gas turbine cogeneration plant integrated with LFR concentrated solar power field. Different electricity generating capacities of the gas turbine and different areas of solar collectors have been examined. Thermoflow software simulation results have been used to identify the optimal configuration and sizing of the gas turbine and the solar field of the integrated solar gas turbine cogeneration plant (ISGCPP) required to achieve the required steam generation with the minimum cost and environmental impact. The study revealed that ISGCPP can reduce the levelized electricity cost by 76–85% relative to the fully-solar-powered LFR power plant. Moreover, the study identified the configuration of ISGCPP with a gas turbine size of 50 MWe capacity and 93 ha of LFR solar field as the optimally integrated plant. It reduces the annual CO 2 emission by 100 k Tonne (18%) in comparison with that emitted by the corresponding conventional plant with 50 MWe and 400 k tonne (43.75%) compared with that emitted by the original conventional plant with a gas turbine if 150 MWe power generation capacity. The study revealed also that integrating the LFR technology with a gas turbine cogeneration power plant in locations with high solar insolation was proved to have more economic feasibility than CO 2 capturing technology. Under Dhahran weather conditions, the LEC of about 5 USȻ/kW h is obtained using the proposed optimally configured ISGCPP compared with about 7.5 USȻ/kW h obtained by the corresponding conventional cycle integrated with carbon capture technology. In other words, the ISGCPP reduces the LEC by 50% while achieving the same reduction of CO 2 emission by an equivalent conventional plant integrated with carbon capture technology.