Collector Outlet Research Articles

Direct Steam Generation Methodology in Horizontal Tubes for Parabolic Trough Solar Collectors Designing

Purpose: The present work has the objective to describe the methodology that is been carried out for the optimization of a computational tool for Parabolic Trough Solar Collector (PTC) designing and assessment, the optimization is centered in a new section where de solar collector produces steam directly, named Direct Steam Generation (DSG). Theoretical reference: A PTC collector consist of a sheet with parabolic cross section with a high reflectance surface, at the focus of the parabola is placed a tube whose material must have high thermal conductivity, this tube must be recovered by a selective coating for high solar radiation absorptivity and less emissivity. Surrounding the absorber, a coating transparent tube is placed concentric with high solar radiation transmissivity value. Into the absorber tube, the heat transfer fluid gains energy due to the concentration of the solar radiation giving as a result, a temperature increase at the outlet of the solar collector. Inside the absorber tube, the working fluid considered in this work is water, due to the objective is to produce steam directly. At the first and third section of the tube, preheating and overheating respectively, a full developed single phase flow is considered and the heat transfer depend on the Reynolds number, Prandtl number, the geometry and conductivity of the tube, related on Dittus-Boelter equation. The mayor analysis is located in the evaporation section, because of the flow patterns formation, depending directly on the mass flow and the steam quality, the Froude number indicates the flow pattern formed during the evaporation process, being the stratified and annular flow patterns the most significant. Method: The first version of the computational tool has some limitations: heat transfer fluid doesn´t have phase change, it means, liquid state is maintained, the parabola rim angle is 90° and only one concentric coating tube is considered. The software’s optimization is centered on the PTC collector designing and assessment for direct steam generation system (DSG). For this purpose, the absorber tube is divided into three sections: first for preheating, where water enters to ambient temperature and at the end reaches saturation temperature, at second section, the evaporation process begins with the water in saturated liquid state and ends to saturated steam state and at the third section, steam is superheated reaching the temperature´s condition imposed by the user. At the evaporation section, the heat transfer coefficient depends on the flow patterns formation as well as the pressure drop, where a separated flow model is applied for this analysis. Results and Conclusion: The optimization methodology for a computational tool, that is used for parabolic trough solar collector designing and assessment for direct steam generation system was analyzed. The absorber tube is divided into three segments, the first one for preheating, reaching the water from initial temperature to saturation temperature for the working pressure, the software will find the minimal length for reaching that condition and necessary mass flow is computed. The second step is evaporation, maintaining constant mass flow, evaporation begin when the saturation temperature is reached at the saturated liquid state and finishes at the saturated steam point, and the software find the minimal length for reaching this condition. The most important and complex variable for this section is the heat transfer coefficient, because of the formation of flow patterns, dominating two main phenomena, nucleate boiling and convective boiling, which are determined using the Froude number. Once saturated steam condition is covered, next section overheats the steam and the software finds the minimal length for the final temperature condition dictated by the user, also the quantity of steam produced maintaining constant mass flow condition. Finally, for the two phase flow phenomena carried out at the evaporation zone, the pressure drop is considered, analyzing some methods for frictional pressure drop in two phase flow, Friedel method is recommended due to the applicability and accuracy. Implications of research: The comprehension of PTC designing with DSG system implies a good knowledge of heat transfer in forced two phase flow into circular tubes, as well as pressure drop using a separated flow model. Originality/value: Using the methodology described in this work, the software´s applicability and versatility is enhanced, because of the implementation of another PTC collector configuration, generating steam directly, avoiding the use of great heat exchangers and synthetic oils as working fluids, which implies the reduction in the installation size and diminishing the total installation price.

Thermal Performance Solar Flat Plate Collector and Influence of Flow Pipe Design

Flat plate collectors are commonly utilized in both domestic and industrial applications to minimize energy consumption. In this study, solar flat plate collector (SFPC)) with corrugated flow pipe with ten turns placed over flat absorber plate and covered with single glass layer was fabricated and tested, in Al-Mussiab city, Babylon, Iraq (latitude 32.5◦N and longitude 44.3◦E). This research presents the effect flow pipe shape about the SFPC's thermal performance. The designed solar collector utilized employing of 12.5 mm-diameter corrugated copper tubing that extended 19500 mm in total length. According to different rates of water flow namely (50, 100, and 150 L/h). The results indicated that the working fluid's greatest temperature differential between the inlet and outlet of solar collector (12.9°C) at volumetric flow rate (50 L/h). The maximum thermal efficiency (Ƞth) rate of solar flat plate collector was (77%) at (150 L/ h). These results encourage the development of solar collector system and eventually help the sustainable use of solar power in home applications, including solar water heating system.

Experimental Investigation of Two-Pass Solar Dryer with V-Corrugated Absorber for Potato Slice Drying

Reducing the moisture level of food items can help prevent bacterial development and deterioration, extend shelf life, reduce packaging, and improve storage for convenient transportation. In this paper, a two-pass solar dryer with V-Corrugated absorber plate is developed. Its experimental performance evaluation in forced convection is carried out for potato chip drying. Various parameters like Hourly Variation of Solar Radiation Intensity, Temperature Distribution Curves inside Solar Dryer, Collector Efficiency Curve, Hourly Mass Loss of Potato Slices and Moisture Removal Comparison with Conventional Open Sun Drying Method are calculated and presented graphically. The peak temperature of the absorber plate reached 69.30C, and the air temperature at the collector outlet recorded the highest value at 57.50C. The average temperature difference of 28.580C is obtained for heat transfer by convection between the modified corrugated absorber plate and the air. An important finding in this experimental investigation was that there is an average 6.50C difference in temperature between the hot air exiting the collector and the air available at the bottom of the lower tray of the drying chamber, which should be reduced by applying means of avoiding heat loss. The highest collector efficiency is calculated as 88.9 % at 2 PM. The lowest efficiency is calculated at 9 AM as 66.8 %. The thermal inertia of the system adds to the collector efficiency in the last 2 hours of the experimentation and hence collector performs better than in the morning hours, though the insolation is nearly the same for the first and last two hours of sunshine. The percentage reduction in drying time was found to be 38.9 % for 50 % moisture removal from potato slices as compared to open sun drying.

Feasibility study of a metal hydride-based solar thermal collector system

The present study aims to assess the technical feasibility of a novel Metal Hydride-based Solar Thermal Collector (MH-STC) system. This system includes a flat-plate solar collector integrated with a metal hydride bed, a hydrogen compressor, a photovoltaic panel, a hydrogen tank, and a water storage tank. This system combines the principles of a conventional solar thermal collector with the energy storage capabilities of metal hydrides, enabling the storage of surplus thermal energy. The LaNi5 alloy was used as heat storage material. A 3D-mathematical model is established and a numerical code written in Fortran-90 is developed to simulate the dynamic behavior of the proposed solar thermal collector. It was shown that the developed 3D-model produces computational results that are consistent with experimental data. In addition, to check the accuracy of the mathematical model and numerical approach, the relative errors in the mass balance and energy balance were calculated and values of 0.054 % and 0.18 %, respectively, were obtained.The simulation results offer insights into the system's technical feasibility, revealing an overall efficiency of 90.6 %, the water temperature at the collector outlet can reach 357.3 K, and a water volume heated of 230.4 L under the considered operating conditions. Moreover, the results indicate that the proposed MH-STC system exhibits significant potential as a viable alternative for thermal storage in domestic hot water systems.

Numerical and Experimental Determination of Selected Performance Indicators of the Liquid Flat-Plate Solar Collector under Outdoor Conditions

The paper proposes applying an in-house mathematical model of a liquid flat-plate solar collector to calculate the collector time constant. The described model, proposed for the first time in an earlier study, is a one-dimensional distributed parameter model enabling simulations of the collector operation under arbitrarily variable boundary conditions. The model is based on the solution of energy balance equations for all collector components. The formulated differential equations are solved iteratively using an implicit difference scheme. To obtain a stable numerical solution, it is necessary to use appropriate steps of time and spatial division. These were found by comparing the results obtained from the model with the results of the analytical solution available in the literature for the transient state, which constitutes the novelty of the present study. The accuracy of the results obtained from the model was verified experimentally by comparing the measured and calculated history of the fluid temperature at the outlet of the collector. The calculation of the collector time constant is proposed in the paper as an example of the model’s practical application. The results of the time constant calculation were compared with the values obtained experimentally on the test stand. This is another novelty of the presented research. The analysed collector instantaneous efficiency was then calculated for selected outdoor conditions. The presented mathematical model can also be used to verify the correctness of the collector operation. By comparing, on an ongoing basis, the measured and calculated values of the fluid temperature at the collector outlet, conclusions can be drawn about the process of solar glass fouling or glycol gelling. The simplicity of the model and the low computational demands enable such comparisons in an online mode.

ANALYSIS OF PROPYLENE GLYCOL/ETHYLENE GLYCOL HEATING IN THE CYLINDRICAL CHANNEL OF THE SOLAR HEAT COLLECTOR

When designing solar thermal collectors, non-stationary operating conditions of the solar system are considered to determine the instantaneous heat output and temperature of the heat carriers during a given day or period. It is known that the amount of useful heat absorbed by a solar thermal collector is directly dependent on the temperature of the heat carrier at the inlet and outlet of the solar thermal collector. The calculation of the heat consumption and/or storage system also requires the temperature of the heat carrier at the outlet of the solar collector. The heating of the heat carrier in a solar collector can be divided into two stages: heating of the walls of the heat exchanger (cylindrical channel) in a solar thermal collector by solar energy and heating of propylene glycol/ethylene glycol in the heat exchanger (cylindrical channel) of a solar thermal collector. This paper presents seven methods for determining the temperature field of the walls of the heat exchanger (cylindrical channel) of a solar thermal collector, depending on the initial and boundary conditions. The most general case for calculating the temperature field of propylene glycol/ethylene glycol moving in the heat exchanger of a solar heat collector assumes the presence of heat exchange on the surfaces of its contact with the walls of the cylindrical channel and with the environment. The calculation takes into account the difficulties associated with the significant nonlinearity of boundary conditions of the "given surface radiation" type. That is, it is taken into account that one surface of the heat exchanger channel is turned to solar radiation, and the opposite is turned to the back wall of the solar heat collector. The solution is found analytically using the method of Green's functions.

Exploring forced convective solar drying of henna (Lawsonia inermis) and its effect on the biological activities: Comparison with open sun dried product

The first focus of this study is to investigate the design and behavior of locally built solar dryer during processing henna leaves. This was performed through the determination of the most important parameters that effect drying process. Appropriately, it was found that solar radiation has a direct effect on the collector outlet air temperature and consequently the product moisture content. Accordingly, high radiations lead having high air temperature at the drying chamber and consequently, the moisture content will decrease rapidly. Similarly, lower radiations will still lead to decrease of the moisture content, however, the drying rate will be less important than at high radiations. On the other hand, air velocity has an inverse dissipative effect of the energy and its increase leads to the decrease of the outlet temperature of the solar collector. Indeed, the highest outlet temperature from the solar collector was around 32 °C at an air velocity of 2 m/s. At 5.5 m/s, this temperature dropped to around 27 °C. The second objective of this study is to present the effect of different drying methods (i.e. forced convective solar drying and open sun drying) of Lawsonia inermis on the content of secondary metabolites (phenolic and flavonoid compounds) and compare the results with fresh henna samples. The yield of phenolic compounds was determined, and the dry crude extracts were found to be richer than the fresh sample in all of the drying modes used. The best yields are obtained with convective solar dryer and open sun drying samples (28.6 and 13.93%), respectively. The total phenolic and flavonoid contents of convective solar dryer product were 25 and 10% higher than open sun dried samples. Antioxidant tests (DPPH, ABTS, and ferric reducing power) revealed the scavenging and reducing abilities of the extract dried with the solar dryer. The values of antioxidant capacities measured by the three different methods were all consistent, appropriate, and highly correlative for assessing total antioxidant capacities. The solar dryer allows the preservation or even the increase of the antioxidant activity of the tested extracts.

Exploration Of Key Approaches to Enhance Evacuated Tube Solar Collector Efficiency

Exploration Of Key Approaches to Enhance Evacuated Tube Solar Collector Efficiency

Investigation of thermal performance, drying characteristics and environomical analysis: direct flow evacuated tube solar drying of okra.

A direct flow evacuated tube solar dryer (DF_ETSD), a novel drying system, was used for drying pre-treated okra (Abelmoschus esculentus). The performance of DF_ETSD was analysed by determining thermal profiling, dryer and collector efficiency hourly. The maximum 3-day average ambient temperature, collector outlet temperature and solar radiation were 35.6°C, 66.4°C and 976 W m-2 respectively. The collector efficiency increased as solar radiation increased over time due to a higher temperature difference between the collector outlet and ambient temperature. The maximum collector and dryer efficiency observed were 30.19% and 21.47%, respectively. A pre-treatment of okra was done in hot water at 70, 80 and 90°C for 5min. Okra samples were dried from an initial moisture content of 87.42 ± 1.49% (wb) to a final value of 10.77 ± 1.03% (wb) in 9h. The pre-treatment temperature of 80°C is suitable for maximum drying rate, colour retention and rehydration ratio and minimum water activity, which signifies the longer shelf-life of okra. Midilli and Kucuk model was best fitted (highest R2, lowest χ2 and RMSE) for the control and samples pre-treated at 80°C; however, Verma model was suitably fitted for the sample pre-treated at 70 and 90°C. The payback period of DF_ETSD was found to be 1.27years. Environmental analysis shows the CO2 emission and net CO2 mitigation ranged between 1.24 and 18.65 t and 9.86 and 154.05 t respectively for different selected lifecycles of the dryer. Due to its environmental sustainability and low payback period, the presented drying system is recommended for okra and other fruits and vegetables.

Performance analysis of solar photovoltaic thermal (PV/T) dryer for drying moringa leaf

Though its considerable solar energy potential prevents equal distribution throughout the region, Indonesia has not made the best use of it, particularly when it comes to integrated drying and electrical technologies. There are a number of drawbacks to traditional direct drying, particularly with regard to food goods. These include the possibility of contamination, discolouration, and animal disturbance. The purpose of this research is to develop, build, and evaluate an integrated drying technology—a solar photovoltaic thermal (PV/T) dryer—that can generate heat and electricity at the same time. The dried material used in this dryer is moringa leaves. This study employs an experimental design methodology, first developing and building a greenhouse-style PV/T dryer with three levels of shelves. Second, a test of the tool's functionality was conducted using 1000 grams of material on each shelf. Measuring devices such digital thermocouples, multimeters, solar power meters, and humidity meters are utilized to get test parameter data. The average daily solar intensity, according to the research findings, is 436.60 watts/m2. Shelf 1, which is next to the collector outlet, had the highest average temperature (53.9 °C), whereas shelf 3 had the lowest average temperature (37.1 °C). With an average voltage of 30.89 volts and an average current of 4.08 amperes, solar panels generate an average power of 85.65 watts. In the meantime, the material's mass decreased after drying for nine hours, on average by 72%, according to the drying data. With an average power of 86.65 watts, an average temperature on the third shelf between 37.1 °C and 40.6 °C, and an average mass reduction of 72%, it can also be stated that this PV/T dryer is quite successful for drying.

Thermal and dynamic improvement of a double pass solar air heater for drying applications

The low efficiency of solar thermal systems is a drawback that hinders the effective utilization of renewable energy. In this context, a feasibility study was conducted on a double-pass solar air heater designed for solar drying applications. Given that low efficiency often results from inefficient thermal conversion, an optimization of the V-shape absorber was performed by varying the corrugation angle. The CFD method, validated by experimental results, was employed in the current study. The meteorological station located at Mohamed First University in Morocco provided real and unstable weather conditions that were inserted into the software. The results obtained were analyzed and discussed regarding the air domain temperature, collector outlet temperature, collector efficiency, and average drying tray temperature together with its distribution. The findings show that the average air temperature and outlet temperature reach a maximum of 345.53 k and 365.5 k, respectively. For absorber corrugation angles of Φ=100°, a maximum collector efficiency of 86% was achieved. In addition, different mass flow rates (MFRs) ranging from 0.003 to 0.068 kg/s were evaluated in this study. From the results, it was noticed that the optimal MFR varies depending on the products to be dried, with values of 0.028, 0.035, 0.049, and 0.068 kg/s for sweet potato, fig, cauliflower, and orange, respectively.

Simulation model of a flat plate air solar collector

Simulation model of a flat plate air solar collector

Thermodynamic performance evaluation of a novel solar-assisted multi-generation system driven by ammonia-fueled SOFC with anode outlet gas recirculation

The cracking of ammonia to produce hydrogen and nitrogen at high temperatures, without carbon dioxide emissions, has great potential for future energy development. Hence, a novel solar-assisted multi-generation system driven by ammonia-fueled SOFC with anode outlet gas recirculation is proposed and the thermodynamic models are constructed. Under the design conditions, the exergy efficiency, and primary energy saving rate of the novel system in summer are 47.83%, and 51.36%, respectively, while in winter, they are 50.52%, and 52.01%, respectively. Meanwhile, the thermodynamic performances of the new system and two reference systems are compared, in which the reference system 1 isn't coupled with a solar collector, and SOFC adopts an anode outlet gas recirculation layout, the reference system 2 has neither coupled solar collector nor anode outlet gas recirculation arrangement for SOFC. The results demonstrate that the anode outlet gas recirculation layout and coupling solar collectors in SOFC help to reduce the fuel consumption of the system. Moreover, the subsystem's exergy flow diagrams under the design condition reveal the exergy destruction of the components. And the impacts of key factors including SOFC operating temperature, fuel utilization rate, direct normal irradiance, and hydrogen recovery factor are analyzed.

An experimental investigation of the thermal performance of solar collectors utilizing finned aluminum can pipes

An innovative experimental study is presented to improve the performance of solar collectors designed for solar drying systems, focusing on the use of recycled aluminum can waste and the development of the air solar collector. The latter’s absorber is made up of 10 cans with a diameter of 65 mm, a length of 160 mm and a thickness of 0.3 mm, forming a cylindrical finned pipe. Several collector configurations under identical weather conditions, including four collectors with different rows of rods (4, 8, 12–14 rows) and a single collector, were analyzed and compared. The thermal performance of this new collector model was assessed on the basis of solar fluxes and collector inlet and outlet temperatures, collected during the month of September 2021. Experimental results revealed that this collector can increase the outlet temperature of air from 32°C up to 130°C, in the case of a 14-row collector. The study also showed that, at low flow rates, the can-equipped collector achieves an efficiency of 54% for the case of a 14-row collector, compared with 34% for the simple case, representing a 20% improvement over the single case. The study also showed that, at low flow rates, the can-equipped collector achieves higher outlet temperatures.

Integrated photovoltaic-thermal system utilizing front surface water cooling technique: An experimental performance response

In the realm of photovoltaic-thermal (PVT) systems, optimizing operating temperatures for photovoltaic (PV) panels is a challenge. This study introduces a novel solution: a sprayed water PVT system that simultaneously harnesses energy and electricity. The aim is twofold: generate electricity through PV panels and produce hot water via a flat plate collector, using an innovative cooling mechanism. Water sprayed onto the PV panel's surface flows to a collector for storage. With varied flow rates, optimal panel efficiency occurs at a 45⁰ tilt angle, accompanied by lower collector outlet temperatures at higher flow rates. The collector achieves a peak thermal efficiency of 70.6 %, producing hot water at 84.6 °C. Notably, a significant PV panel efficiency enhancement, up to 16.78 %, especially at 1.56 L/min flow rate, is observed. The cooling technique consistently reduces panel temperatures from 45.08 °C to 34.12 °C. A self-cleaning spray mechanism improves efficiency by 2.53 %, resulting in an overall system efficiency of 83.3 %. This research offers an innovative approach to enhance energy generation and electricity in PVT systems, promising sustainable energy optimization.

Coordinated control strategy for concentrated solar power systems considering active defocusing

With an increasing proportion of renewable energy in the energy structure, concentrated solar power plants are required to respond rapidly to automatic generation control (AGC) commands, to ensure the grid stability when connected to the grid. Active defocusing affects the collecting capacity of the collector, which not only serves as a safety protection measure for system operation, but also improves the system load shedding rate and provides the possibility of system participation in the auxiliary service of grid frequency regulation. In this paper, a coordinated control strategy for parabolic through concentrated solar power (PTCSP) system considering active defocusing of collector is proposed. The coordinated controller utilizes four manipulated variables, including mass flow rate of heat transfer oil in the collector, active defocusing angle, mass flow rate of molten salt in the heat storage system, and main steam valve opening, to regulate three output variables, namely, collector outlet temperature, turbine power, and main steam pressure. By integrating the steady-state defocusing angle in the optimization function, the controller can utilize the extra control freedom degree to improve the control effect, and ensure that the final steady-state defocusing angle to be small, which reduces the unnecessary heat collection loss. The proposed control strategy improves the power response rate and also avoids excessive heat transfer oil temperature and main steam pressure. In the simulations featuring two 20% variations in load target value, the root mean square error of the outlet temperature of the collectors is reduced by 0.094, and the heat storage is reduced by 0.99 MWh.

Testing The Heat Distribution of Flat Plate Type Solar Collectors for LPG Solar Hybrid Dryers at P4S Bukit Melintang

One of the uses of solar energy in agriculture is as a source of heat energy for dryers. Through the Kedaireka 2023 Matching Fund (MF) activity and in collaboration with the Independent Rural Agricultural Training Center (P4S) of Bukit Melintang, Sidrap Regency to develop a hybrid solar and LPG dryer. Thermal energy from the sun is obtained from a flat plate-type solar collector system. This research aims to obtain a flat plate-type solar collector system as an alternative heat source for hybrid dryers. The research was carried out to test the functional tool and determine its performance in converting solar energy into heat that can be used for drying equipment. The results of tests carried out on October 22, 2023, from 10.25 AM to 13.35 PM at the Agricultural Engineering Study Program, Hasanuddin University, with coordinates -5.131048, 119.485434 showed that the average environmental temperature was 36.5 °C, the highest temperature in the solar collector outlet was 57 °C which occurred at 11.15 – 11.40. and experienced a decrease in temperature until 13.35 to the lowest temperature of 42.5 °C. This shows that the solar collector can increase the temperature from 60 to 20.5 °C.

Improvement of the classical artificial neural network simulation model of the parabolic trough solar collector outlet temperature and thermal efficiency using the conformable activation functions

The outlet temperature and the thermal efficiency predictions of the PTSC are essential parameters in the solar thermal power system. Therefore, it is crucial to have a prediction model that can predict its spatiotemporal behavior to the greatest extent possible. For that, the present study provides improved models of the classical ANN model by using ELU, swish, softplus, logsig, and tansig functions through the exponential transfer function to improve the outlet temperature prediction performance and thermal efficiency of PTSC. The PTSC’s outlet temperature simulation showed that the ANN model of topology 6-2-1 with the conformable swish transfer function (cswish) was the best model among nine other studied models, with an R2 and Radj2 of 0.9988, and MAE of 0.0052. The simulation of PTSC’s thermal efficiency proved that the conformable functions logsig, tansig, ELU and the classical ELU function involved in the ANN model for 6-3-1 achieved better results with approximately 95% precision. With the non-integer activation functions, was reduced a neuron in the hidden layer, which leads to the simplicity of the prediction model compared to the use of the classical activation functions. The proposed activation functions do not require high-performance features according to their execution times. Therefore, it could be a good alternative for engineers to apply in other thermal energy systems to make their prediction models more accessible and practical in the control and optimization process.

Performance analysis of a forced indirect cabinet solar dryer for drying figs

In the solar drying process, a lower air velocity is unable to rapidly extract moisture from the products to the outside, while a higher air velocity has a negative effect . To improve the final quality of the dried products, the effect of air inlet velocity (0.1, 0.3, and 0.5 m/s), air outlet position, and inlet size of an indirect solar dryer operating in forced convection was studied . The Computational Fluid Dynamics (CFD) method, validated by experimental results, was used for this investigation while the meteorological data used to define the boundary conditions are exported from the meteorological station. The obtained results show that the average temperature of tray 1 reaches 314, 311.75, and 311 K for the right, middle, and left outlet positions, respectively, with an inlet velocity of 0.1 m/s. In addition, the average collector outlet temperature is higher (329 K) for the 0.05 m inlet size. The trays temperature peaks at 2 pm on the selected day, with an average temperature of 326 and 324 for trays 1 and 2, respectively. Based on the current results, the farmers will have a good insight into the parameters for the realisation of a solar dryer.

Techno-economic analysis of an indirect solar dryer with thermal energy storage: An approach with machine learning algorithms for decision making

Machine learning models effectively forecast and improve engineering systems as solar dryers, making them valuable replacements for traditional physics-based models. Also, according to the literature, there is a research gap in solar drying regarding the lack of a comprehensive comparison of machine learning algorithms, neglecting the importance of cross-validation and tuning parameters. Therefore, this research focuses on employing machine learning models as effective surrogate models for solar dryers that attend to this gap, reducing the computational burden. A methodology for developing and comparing machine learning surrogate models of three indirect solar drying technologies (conventional, energy storage with beach sand, and storage with limestone) is proposed. The algorithms were trained using the database generated from a tomato solar drying process, where the solar dryer type, solar irradiance, ambient temperature, wind velocity, and relative humidity were considered model inputs to estimate the absorber plate, solar collector outlet air, and drying chamber outlet air temperatures. Subsequently, from the best predictive algorithm, a techno-economic analysis was conducted annually. The results revealed a high accuracy (R2 of 0.9917) and similar values regarding metrics that measure precision and variance. The solar dryer with thermal energy storage using beach sand exhibited the highest thermal and drying efficiency values (52.52 % and 12.57 %, respectively), while the limestone variant reported the shortest drying time (22 h). The economic evaluation indicated minimal monetary loss (3.09 %) compared to the current system’s annual projection. Finally, the framework presented in this research emphasizes using machine learning models to forecast the system’s energetic and economic performance indicators and contributes as a substitute for experimental studies that involve high cost and long duration. This work lays the bases and guides future research where machine learning algorithms are needed to compare energetic systems’ best computational and techno-economic performance.