Solar Air Conditioning System Research Articles

Design of solar thermal absorption air conditioning system using CO2 with synthetic building load

Traditional air conditioning and refrigeration solutions rely on compressor-driven systems, leading to increased electricity consumption and intensified greenhouse gas (GHG) emissions. These systems primarily utilize synthetic refrigerants such as CFCs, HCFCs, and HFCs. Despite their advantages, these refrigerants are either banned or subject to restricted permissions under the Montreal Protocol (1987) and the Kyoto Protocol (1997) due to environmental concerns. According to the Paris Accord, ratified by 196 parties as of 2017, there is a global shift towards low global warming refrigerants and eco-friendly alternatives. COP27 reaffirmed global commitments to limit temperature rise to 1.5 °C, emphasizing urgent action and stronger climate plans to combat global warming. CO2 envisaged by ASHRAE is resurrected as a promising natural refrigerant with the advent of high-pressure technologies the design employs a solar evacuated glass tube collector (EGTC) with U-shaped copper tubes and flat plate collector (FPC) to harness solar thermal energy. An immersed heat exchanger's (HX) based thermal storage tank is incorporated to address the intermittency of solar energy. The CO2 refrigerant offers advantages over other natural refrigerants due to its low critical point.This research conducts a TRNSYS® simulation of a 35.2 kW absorption cooling system with synthetic building load driven by energy captured through FPC and EGTC using R-744, additionally supported by a supplementary boiler for traditional office timing. The system design comprises two solar collectors, the EGTC and FPC, integrated with two different cooling loop configurations (C1 and C2). In C1, the hot water that exits the generator of the absorption chiller is forwarded toward the immersed HX-based hot storage tank, which is connected to the solar and absorption cooling loop. In C2, the working fluid leaving the absorption chiller is diverted directly toward the auxiliary boiler/furnace, if the temperature in the storage tank falls below the necessary level (108.89 °C) and if the tank temperature is greater than this set point temperature, then the flow passes through the storage tank. Both system designs have been developed using TRNSYS, with dynamic simulations conducted throughout the summer.The solar fraction and collector efficiency are considered as key performance indicators to evaluate and compare the system's effectiveness. Then the optimization of system parameters is performed for all four cases (EGTC C1 & C2 and FPC C1 & C2) based on these key performance indicators, all configurations integrated with a fixed synthetic building cooling load. The optimum parameters are found for all four cases, and the optimum parameters for EGTC C1 & C2 are 100 m2, 4 m3, and 11° for collector area, storage tank volume, and collector slope respectively. Similarly, for FPC based configurations, these parameters are 200 m2, 32 m3 for C2 and 4 m3 for C1, and 20° respectively. The results revealed better C2 performance than C1, with EGTC outperforming FPC. The final results were computed for the EGTC based designs due to their high solar fractions, with EGTC C2 emerging as the optimal configuration, achieving a seasonal solar fraction of 0.649.

Performance Predication of a Solar Assisted Desiccant Air Conditioning System Using Radial Basis Function Neural Network: An Integrated Machine Learning Approach

In this Paper solar desiccant air conditioning system integrated with cross flow Maisotsenko cycle (M-cycle) indirect evaporative cooler is used to investigate the performance of whole system in different range of parameters. Solar evacuated tube electric heater is used to supply the regeneration temperature to the desiccant wheel, whereas, Desiccant Wheel (DW) and M-cycle is used to handle latent load and sensible load separately. Major contribution of this research is to predict system level performance parameters of a Solar Assisted Desiccant Air Conditioning (Sol-DAC) system using Radial Basis Function Neural Network (RBF-NN) under real transient experimental inlet conditions. Nine parameters are mainly considered as input parameters to train the RBF-NN model, which are, supply Air temperature at the process side of desiccant wheel, supply air humidity ratio at process side of the desiccant wheel, outlet temperature from the desiccant wheel at process side, outlet humidity ratio from the desiccant wheel at process side, regeneration temperature at regeneration side of the DW, outlet temperature from the heat recovery wheel at process side, outlet humidity ratio out from the Heat Recovery Wheel (HRW) at process side, temperature before heat recovery wheel regeneration side of the system, humidity ratio before heat recovery wheel regeneration side of the system. Four parameters are considered as the output of the RBF-NN model, namely: output temperature, output humidity, Cooling Capacity (CC), and Coefficient of Performance (COP). The results of the RBF-NN model shows that the best Mean Squared Error (MSE) and Regression coefficient (R) for outlet temperature prediction are 0.00998279 and 0.99832 when regeneration temperature is 70°C and inlet humidity at 18 g/kg. Best MSE and R for predication of outlet humidity are 0.0102932 and 0.99485 when the regeneration temperature is 70°C and inlet humidity at 16 g/kg. Best MSE and R for predication of COP are 0.0106691 and 0.9981 when the regeneration temperature is 70°C and inlet humidity 12 g/kg. Best MSE and R for predication of CC are 0.0144943 and 0.99711 when the regeneration temperature is 70°C and inlet humidity 14 g/kg. Experimental and predicted performance parameters were in close agreement and showed minimal deviation. Investigations of predicted results revealed that trained RBF-NN model was capable of predicting the trend of output result under the varying input condition.

Experimental investigation of a photovoltaic solar air conditioning system and comparison with conventional unit in the context of the state of Piaui, Brazil

Globally the building sector is responsible for a big share of electric energy consumption and emissions. To alleviate these impacts it is necessary to improve the energy efficiency besides implementing renewable energy sources for building sector sustainability. PV panels for generating electric energy are most preferred by the sector. In the present study, two similar rooms were prepared one with a conventional air conditioner of the window type powered from the grid and the other is powered from PV panels. The heat load was calculated and used to define the conventional air conditioner and also to define the area of photovoltaic solar panels and the associated equipments to install a PV circuit for supplying electric energy to the PV air conditioner. Both rooms were equipped with calibrated instrumentation including thermocouples to measure the temperature distribution in rooms as well as electric energy consumption during the experiments. Ambient temperature, wind speed, temperature in the vicinity of the photovoltaic panels, humidity, solar radiation, voltage, current, flow of energy consumed by the systems were measured and registered by data acquisition system. Experiments were carried out with the systems working simultaneously at pre-defined times. The solar PV-based air conditioner consumed approximately 342 kWh during 30 days of experiments, while the air conditioner connected to the grid, consumed about 330 kWh, which is 5 % less than the solar PV air conditioner confirming that solar PV air conditioner is viable. The COP for the solar-based air conditioner is about 2.6 and the COP for conventional air conditioner is 2.9. The incident solar radiation is high and stable in Teresina, Piauí, Brazil which ensures viability of the solar PV air conditioner. The power supply from CC showed better quality and costs an AC system, and that PV System can save about $700.00 in energy consumption and the payback occurs in 3.7 years.

Field test study on thermal performance of a novel embankment using solar refrigeration technology

The embankment construction in permafrost regions affects the energy exchange process between the original ground and the surrounding environment, accelerates the degradation of the underlying permafrost layer, and endangers the stability of the embankment. To prevent permafrost degradation, a solar air conditioning system based on solar refrigeration technology was proposed. In this study, a field test of cooling embankment was carried out in permafrost regions, and the cooling performance of the new technology was analyzed. The solar air conditioning system shows good cooling performance, with a horizontal influence range of about 1.77–2.28 m and a vertical influence depth of more than 3 m. By active cooling, the temperature of the permafrost layer beneath the embankment decreased significantly, and the permafrost table rose by about 0.3 m. In addition, the influence mechanism of complex environmental factors on the cooling performance of the solar air conditioning system was revealed by correlation analysis and machine learning methods. Compared with existing technologies, solar refrigeration technology achieves active refrigeration during the whole season and presents a significant price advantage. The research results help promote the application of solar refrigeration technology in transportation geotechnics and provide a new approach for actively cooling embankments.

Energy saving and economic competitiveness of solar desiccant cooling technology – A case study of the Moroccan Kingdom

As many countries in the world, Morocco is vulnerable to climate change having direct impacts on its main economic sectors highly dependent on natural resources. This is exemplified, among other things, by long periods of drought, increase of average temperatures and successive heat waves. These circumstances have increased the demand for cooling energy, particularly in tertiary building where centralized air conditioning systems still predominant. Currently, the installed power capacity seems to be insufficient to respond effectively to this increasing demand. In this context, sustainable alternatives to traditional cooling systems such as solar air conditioning systems can be a suitable option for energy efficiency and security. Solar desiccant cooling systems present a great opportunity since they do not use any ozone-depleting coolants. This study discusses the techno-economic feasibility of solar desiccant systems in tertiary building, in particular a conference room, compared to a conventional air handling unit. Besides the use of air solar collectors to heat up the regeneration air, the particularity of the studied system is the use of exhaust air leaving the desiccant wheel and purge zone to preheat regeneration air. Accordingly, simulations were performed in three climatic regions with different enthalpy loads. The main result of this work is that solar desiccant cooling system can be an attractive investment if appropriate economic conditions are met with a substantial governmental support, since a significant energy-saving of about 77% can be achieved compared to conventional systems.

Modeling and simulation of absorption solar air conditioning to reduce energy consumption: A case of some cities in tropical region

Buildings are one of the most important infrastructure sectors in today’s society. However, in Madagascar, most hotels, malls, hospitals use fossil fuels to meet energy needs, especially in the traditional air conditioning system. they consume a considerable amount of energy that has negative effects on the environment. The emergence of solar cooling systems is a very interesting solution to this problem because the use of renewable energies in this sector contributes to a significant reduction of greenhouse gas emissions in the environment. Madagascar is one of the countries with high renewable energy potential, notably solar energy estimated at 2000kWh/m².an.At present, the rate of exploitation of this potential for the operation of the solar absorption cooling system coupled with the building is still non-existent. This energy is clean, sustainable, profitable and environmentally friendly. This is the main objective of this work which uses this energy source to ensure thermal comfort in a building in Madagascar and contributes to the development of this system. The TRNSYS software helped us to model and simulate this system.  To do this, first we will select 4 big cities of the big island, a building of total surface 80 m² was used. Then, the hourly thermal loads of this building for the whole year were simulated using the TRNbuild sub-program using meteorological data for a typical year of the selected cities. The dimensions of the components of the solar absorption air conditioning system were obtained using the maximum loads of the building. The results of the simulations show, the system meets the cooling load needs of the building with the climatic conditions of each selected city.

Simulation of a solar absorption air conditioning system for a tropical wet region in Brazil

Simulation of a solar absorption air conditioning system for a tropical wet region in Brazil

Simulation of a solar absorption air conditioning system for a tropical wet region in Brazil

Simulation of a solar absorption air conditioning system for a tropical wet region in Brazil

Performance Assessment of Solar Desiccant Air Conditioning System under Multiple Controlled Climatic Zones of Pakistan

Over the past decade, the integration of desiccant technology with evaporative cooling methods has proven to be highly effective and efficient in providing comfortable indoor environments. The performance of desiccant-based direct evaporative cooling (DEC) systems is strongly influenced by environmental conditions, and their output behavior varies across multiple climatic zones. It is not easy to assess the system performance in numerous climatic zones as it is a time-consuming process. The current study focuses on determining the feasibility of a solid desiccant integrated with a direct evaporative cooler (SDI-DEC) for three different climatic zones of Pakistan: Lahore (hot and humid), Islamabad (hot and semi-humid) and Karachi (moderate and humid). To serve this purpose, a specially designed controlled climate chamber with an integrated air handling unit (AHU) was installed to create multiple environmental conditions artificially. It could also provide global climatic conditions under temperature and absolute humidity ranges of 10 °C to 50 °C and 10 g/kg to 20 g/kg, respectively. The weather conditions of the selected cities were artificially generated in the climate chamber. Based on different operating conditions, such as inlet air temperature, humidity and regeneration temperature, the performance of the system was estimated using performance indicators like COP, dehumidification effectiveness, solar fraction and supply air conditions. Results showed that the maximum temperature achieved from solar collectors was about 70 °C from collectors with an area of 9.5 m2. Moreover, the observations showed that when the regeneration temperature was increased from 60 °C to 80 °C, the COP of the system decreased about 41% in a moderate and humid climate, 28% in a hot and semi-humid environment and 23% in a hot and humid climate. The results revealed that an SDI-DEC system has the potential to overcome the humidity and cooling loads of the multiple climatic scenarios of Pakistan.

Modeling, optimizing and sizing of a solar air conditioning system with refrigerant storage for meeting the 24-hour cooling load of a restaurant building

A methodology is presented for the sizing of a solar integrated absorption refrigeration system considering the dynamic cooling load, solar energy and ambient conditions. The solar vapor absorption system (single effect, LiBr) is designed to meet the cooling demand of a 200 m2 restaurant building. Using the genetic algorithm, the operating variables of the absorption refrigeration system are optimized The system is to be integrated to a solar collector to meet the varying cooling load profile. The local solar insolation profile at a location is considered in the analysis. The ambient temperature data is utilized to model how the system works in real time. For continuous operation, to meet the 24 h load profile, refrigerant storage is considered for the system. The amount of refrigerant stored is 1529 kg. The optimal area required for the solar collector is found to be 308 m2. The hot water storage tank volume is 5.2 m3. The selection of working fluid (LiBr-water), solar collector (flat plate), and design (single effect system) guarantees that the system is effective, economical, and environmentally favorable.

Design of solar air conditioning system integrated with photovoltaic panels and thermoelectric coolers: Experimental analysis and machine learning modeling by random vector functional link coupled with white whale optimization

Design of solar air conditioning system integrated with photovoltaic panels and thermoelectric coolers: Experimental analysis and machine learning modeling by random vector functional link coupled with white whale optimization

Solar Air Conditioning Case Studies for Qatar Climate Conditions

Abstract Air conditioning (AC) is crucial for comfortable living in countries with challenging desert climates like Qatar. In the face of such harsh conditions, cooling applications account for up to 70% of energy consumption in residential buildings. Given the high-energy demand for cooling and the region's abundant solar resources, rooftop photovoltaics (PVs) can offer an ideal sustainable solution, as peak solar supply closely aligns with the electricity demand. This study aims to enhance the feasibility, effectiveness, and system design for solar ACs in Qatar's climate conditions. A simulation model is developed to evaluate different setups of solar AC systems, utilizing local historical weather data. Optimization strategies are explored and validated for the purpose of minimizing the need for costly battery storage. Results demonstrate the efficacy of these techniques, with potential reductions in battery capacity needs of up to 15% through heat inertia management and matching of energy supply and demand. The complete elimination of battery storage is found to be possible but would be at the expense of slight compromises in end-of-day indoor comfort, which can be addressed by cooling storage solutions.

Grid Interactive Solar PV and Battery Operated Air Conditioning System: Energy Management and Power Quality Improvement

The drop in solar panel cost over past decade has accelerated the usage of solar photovoltaic (SPV) in various applications. In tropical countries, air conditioning unit is extensively used for cooling comfort. In this paper, PV generation is utilized with a battery energy storage (BES) for an air conditioner to reduce the impact of energy consumption from utility grid. Recently, air conditioning units are adopted with variable speed drive (VFD) that creates peaky nature of the input grid current due to the AC-DC conversion. The diode bridge rectifier (DBR) used for such conversion, does not allow bidirectional current flow. In this paper, considering such facts and taking the benefit of the VFD technology, an energy management methodology is proposed using PV array and BES to reduce the power consumption of air conditioning unit as well as it feeds excess PV generation to the grid with improved power quality. The DC power produced by the PV panel and BES is fed to DC bus of the VFD directly with the help of dual active bridge (DAB) converter, that eliminates DC-AC conversion stage. A voltage source converter (VSC) is interfaced as a front-end converter of VFD, to feed PV generation to the grid when air conditioner is not operating. This system is useful from multistory buildings to small consumers where the air conditioners are extensively used and PV array is installed. The concept of the system is validated by implementing in a prototype in the laboratory scale. The system is investigated with different possible scenarios. Under all test conditions, the THD of the grid current is found within the limits of the IEC 6100-3-2 standard.

Design and analysis of grooved heat pipe

AbstractA heat pipe is a heat conduction program that utilizes both heat permeability and regime shift concepts to transport heat effectively between 2 different lines. A heat pipe is made up of a pipe or tube and a base fluid. In practice, the heat pipe is poured into a mould that is compatible with the cooling media. These devices have found uses in a variety of fields, including space apparatus, solar energy systems, electronic equipment, and air conditioning systems, due to their simplicity of design and ease of manufacture and maintenance. Thermal performance improvement being the major concern in our project we researched different techniques. The heating surface area has a direct impact on heat transfer. Therefore, we have focused on heat enhancement by introducing grooves. Alongside we also considered using different materials for the pipe. At the end of our research, we are going to produce groove structure models with different materials and analyze them using ANSYS software and propose the best structures with highest thermal efficiency for different applications of heat pipes. This is an attempt to increase heat transmission in response to various material and structural changes. Heat transmission is improved with grooved heat pipes as well as heat transmission various with different types materials used in heat pipe.

Smart Solar Cooling System Controlled by the Internet of Things

Comfort and relax is the basic need needed eventually during the summer seasons and has amended an important need, of an hour with the use of such air conditioning and cooling system which is increasing rapidly. The power outages and high initial cost has made it unsuitable for the village areas. Photovoltaic systems are seen as a way for renewable energy in the future, as the solar air conditioning system provides many essential products to the village. The technology improves indoor air quality by monitoring product performance, improving ventilation and controlling humidity. Despite the growing number of design and management guidelines for energy use, the high electricity demand continues to rise and there is currently no solar air conditioning system for residential use at home, especially in cities, businesses and schools. The solar air conditioner with a freezer for food at home has been tested as part of the business, making it ideal for home use. The proposed work addresses this issue and is a design project aimed at maintaining a comfortable temperature inside a car parked in a parking lot or driveway. The proposed work addresses this issue and is a design project aimed at maintaining a comfortable temperature inside a car parked in a parking lot or driveway.

A New Approach to Air Conditioning System Using the Photovoltaic System in Combination With Electricity – Driven Heat Pump and Vapor Compression Chiller

Solar cooling systems have the benefit of the correlation between hours of cooling demand and the availability of solar radiation which can help to minimize electricity usage in buildings. Cooling and/or heating are the major requirements in houses, depending on local climatic conditions and construction style. As well as the impacts of global warming and climate change, air conditioning and refrigeration demands have risen. The development of cooling by using green energies, such as solar panels, is also a crucial solution for electricity and environmental problems. In this research, a solar air conditioning system using pv- vapor compression chiller is proposed. The objectives of this research is to design a system structure to reduce the energy consumption and electricity bill, investigate the performance of the proposed structure through simulation software, implement a hardware prototype based on the proposed design, and to evaluate the simulation and implementation data to validate the experimental results. Finally the data will be validating by the results from other works and simulation as well. DOI: 10.7176/JETP/13-1-04 Publication date: January 31 st 2023

A Review on Performance of Solar Powered Air Conditioning System

Abstract: Solar energy converts the renewable energy to increase growth. The development of energy in to generated worldwide. It in the most easy to construct the process of solar air Conditioning systems. The different energy areinvolved into the solar air conditioning to the decreasing current Sources Then using high oil and concern environmental effects have been Controlling. The most comfortable Process of the solar energy system. It we implemented nowadays, increase in progress. we are air Conditioning systems are using in. every building, malls,Colleges industries, flats, etc. solar power air conditioning system is the hot issue to study building energy Consumer. I Then we indoor and outdoor comfort of air Conditioning while be cold storage system. To increasing the efficiency of air Conditioning intensity of the cooling system. The transient thermal efficiency we can using the storage system to maintain the temperature to indoor,The solar system must be using the different. Parabolic collector from the high accommodation,The basic analysis, to investment of Solar air conditioning system are using 3-phase accumulator. The solar energy using of high rate of low grade energy to high grade of energy are Converting them. It will high efficient process could be panels, collectors, will cool the High temperature can be assumed to use the chilled water storage tank. can be provided due to reduce the system of on and off options. There are improving solar system.It will high efficient process could be panels , collectors, will cool the High temperature can be assumed to use the chilled water storage tank. can be provided due to reduce the system of on and off options. There are improving solar system.it is common for the storage chilling water can be utilized, that can to be operated solar energy.

Adsorption Solar Air Conditioning System for Singapore Climate

The design of an adsorption solar air conditioning system is investigated by using a model with an activated carbon–methanol working pair. This system is analysed with the solar insolation levels and ambient temperatures of Singapore. The proposed design mainly consists of two tubular reactor heat exchangers (TRHEXs) operating out of phase and driven by heat from an evacuated tube solar collector (ETSC). The pair of TRHEXs act as a thermal compressor and contain about 2.275 kg of activated carbon per reactor. The evacuated tube solar collector (ETSC) has better performance and is more cost effective than the flat plate solar collector (FPSC), even though it has a higher cost per unit. On the hottest day of the year, the proposed adsorption system has a maximum cooling power of 2.6 kW and a COP of 0.43 at a maximum driving temperature of 139 °C with a 9.8 m2 ETSC area. The system has a total estimated cost of EUR 10,550 corresponding to about SGD 14,800 with a 7-year payback time. At similar cooling capacities, the adsorption air conditioning system is expected to be more cost effective than the conventional system beyond an expected period of 7 years, with an expected lifetime of 15 to 20 years.

Performance optimization of a solar air-conditioning with a three-phase accumulator based on the energy-economic analysis

The intermittent and instability problem of solar energy is solved by using "three-phase accumulator" with the medium of LiBr–H2O instead of the auxiliary heater in a solar air conditioning (SAC) system based on independent-developed solar parabolic trough collectors (PTC), in which, "three-phase" refers to LiBr solution, LiBr crystal and vapor. The multi-objective optimization is conducted based on the energy and economy analysis. Pareto frontier for the multi-objective optimization has been obtained with NSGA II. The optimal points have been selected by LINMAP and TOPSIS decision-making methods. The multi-objective optimization results show that the solar fraction, the energy storage density and the system efficiency of the SAC system with TOPSIS are 89.67%, 624.67 kWh/m³, 0.833, respectively, compared with LINMAP, which are 88.31%, 604.22 kWh/m³, 0.848. Based on the TOPSIS decision-making results, the annual average investment of the SAC system is 161,100RMBY, the economic indexes of the system, i.e., AFC (annual cash flow), PBP (payback period), NPV(net present value) and IRR (internal rate of return) are 38,100RMBY, 5.53 years, 140,500RMBY and 7.82%, respectively. In addition, the economic sensitivity analysis results show that the prices of PTCs and refrigeration equipment have a greater impact on the economic index.

Utilizing innovative proportional-integral-derivative controllers to reduce solar air conditioning system energy demand

In this study, a new proportional-integral-derivative controllers (PID) system was designed to analyze chiller energy demand (CED) in accordance with current criteria for lowering energy consumption in buildings (TED). By defining parameters of cooling setpoint (CSP) and cooling set back (CSB) schedule, the activity of the air conditioning system along with mechanical ventilation was adjusted well-ordered by the PID controllers. In the first step, it was found that a one-degree change in the CSP parameter had a much superior effect than a three-degree change in CSB. In this study, the heat recovery potential in Riyadh was evaluated and it was found that adding this system with a yield of 0.5 to 0.8, diminished TED in the range of 33.4 to 50%. With the development of a system of PID controllers, the economizer decreased CED by 1 kWh/m2 during CSB. Although the heat recovery system was much more successful than the economizer, to benefit the advantage of both devices simultaneously, a suitable PID system was designed to activate the economizer in CSB time and heat recovery in CSP. Due to the proper combination of these two devices, TED was reduced by 54.3%.