Modeling and experimental validation of a solar-assisted direct expansion air conditioning system

Vakiloroaya, Vahid; Ha, Q.P.; Skibniewski, Mirosław J.

doi:10.1016/j.enbuild.2013.07.073

Cited by 35 publications

(11 citation statements)

References 20 publications

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“…This development is promising between 25 and 43% of monthly electricity can be saved on average. Vakiloroaya et al 2013 [5] derived mathematical models for the components of hybrid solar air conditioner and then validated against experimental results. The models are derived based on the mass and energy balance equations merging thermodynamics and heat transfer laws.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Hybrid Solar Air Conditioning System using a New Control Strategy

Mohammed¹,

Abduljabbar²

2018

alkej

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Enhancement of the performance for hybrid solar air conditioning system was presented in this paper. The refrigerant temperature leaving the condenser was controlled using three-way valve, this valve was installed after the compressor to regulate refrigerant flow rate towards the solar system. A control system using data logger, sensors and computer was proposed to set the opening valve ratio. The function of control program using LabVIEW software is to obtain a minimum refrigerant temperature from the condenser outlet to enhance the overall COP of the unit by increasing the degree of subcooled refrigerant. A variable load electrical heater with coiled pipe was used instead of the solar collector and the storage tank to simulate the solar radiation. Experimental data was measured to study the performance of the system. The proposed system was compared with the conventional one. Results show that the COP of the proposed system was higher than the COP of the conventional system by 10 %. In addition, the controlled system saved an electricity of 11.2 %. The optimum opening valve ratio fluctuated between 0.3 and 0.4 when the heater power was 500 W.

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Section: Introductionmentioning

confidence: 99%

Enhancement of Hybrid Solar Air Conditioning System using a New Control Strategy

Mohammed¹,

Abduljabbar²

2018

alkej

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“…Vakiloroaya et al [8] improved an air-conditioning system combined with a vacuum solar collector in order to benefit from solar energy. A mathematical model of the system components was also developed and validated against experimental results.…”

Section: Introductionmentioning

confidence: 99%

Hibrit bir İklimlendirme Sisteminin Enerji ve Ekserji Analizi

Özbek

2018

Çukurova Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi

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In summer months, an increase in electricity demand with the use of air conditioning systems requires the more economical use of energy. Energy saving can be achieved by using the same work with less energy or by developing the conventional methods. In this study, energy and exergy analysis of a solar assisted hybrid airconditioning system operating in cooling mode is carried out analytically. Performance analysis was then performed comparing with the situation in which no solar energy support was used. Results indicate that solar panel usage improves system COP by 16% and exergy destruction rate increases through the condenser and compressor, but decreases through the evaporator and capillary tube. Furthermore, total exergy destruction and overall exergy efficiency values of the system increase by using the panel.

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“…Because building cooling load varies with the time of the day, an HVAC system could be equipped with an effective controller to reduce the energy consumption by keeping the process variables to their optimal set-point required. This has motivated the work presented in this paper, to reconfigure the system developed in [19] with a refined model validated from experiments, and to design and implement an optimal regulator for its closed-loop multivariable control. The new hybrid solar-assisted system features a discharge bypass line, an inline controlled solenoid valve, a condenser fan with variable speed drive, and a programmable logic controller for closed-loop control of two outputs, namely the temperatures of the refrigerant leaving the condenser and leaving the compressor, respectively.…”

Section: Introductionmentioning

confidence: 99%

Modeling and optimal control of an energy-efficient hybrid solar air conditioning system

Vakiloroaya

2015

Automation in Construction

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The paper addresses the modeling and optimal control problem of a new hybrid solar-assisted air conditioning system developed for performance enhancement and energy efficiency improvement. To regulate the mass flow rate of the refrigerant vapor passing through a water storage tank for increasing the refrigerant's subcooling process at partial loads, we propose a new discharge bypass line together with an inline solenoid valve, installed after the compressor. In addition, to control the air flow rate, a variable speed drive is coupled with the condenser fan. For the control purpose, a lumped parameter model is first developed to describe the system dynamics in an explicit input-output relationship; then, a linear optimal control scheme is applied for the system's multivariable control. The system has been fully-instrumented to examine its performance under different operation conditions. The system model is then validated by extensive experimental tests. Based on the obtained dynamic model, an optimal controller is designed to minimize a quadratic cost function. Numerical algorithms, implemented in a simulation tool, are then employed to predict the energy performance of the system under transient loads. The experimental results obtained from implementation with PLC demonstrate that the newly-developed system can deliver higher system efficiency owing to amelioration of the refrigeration effect in the direct expansion evaporator and adjustment of its air flow rate. The development is thus promising for improvement of energy efficiency, enhancement of the system performance while fulfilling the cooling demand.

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Modeling and experimental validation of a solar-assisted direct expansion air conditioning system

Cited by 35 publications

References 20 publications

Enhancement of Hybrid Solar Air Conditioning System using a New Control Strategy

Enhancement of Hybrid Solar Air Conditioning System using a New Control Strategy

Hibrit bir İklimlendirme Sisteminin Enerji ve Ekserji Analizi

Modeling and optimal control of an energy-efficient hybrid solar air conditioning system

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