Loading...
Publication
Ensaio de equipamento de ar condicionado do tipo split fora das condições nominais por métodos não intrusivos
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 7.19 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
A preocupação com o meio ambiente é cada vez maior, devido ao aumento do aquecimento global e da depleção da camada de ozono. A compra de equipamentos de ar condicionado também tem vindo a aumentar e por sua vez a quantidade de equipamentos utilizados. Uma das falhas mais comuns neste tipo de equipamentos são as fugas de fluido frigorigéneo e muitos dos equipamentos utilizados atualmente têm gases que contribuem de forma negativa para o meio ambiente. Portanto, o desenvolvimento de métodos que permitam identificar este tipo de falhas tem vindo a ser cada vez mais estudado.
Neste trabalho foi projetada e construída uma instalação para ensaios de equipa-mentos de ar condicionado tipo split dentro e fora das condições nominais de carga de fluido frigorigéneo. A instalação é composta por uma câmara construída com um material termicamente isolante e dois ventiladores com caudal volúmico regulável. Foi também construído um sistema que permite recolher ou injetar fluido frigorigéneo, simulando uma situação de avaria. Para a monitorização e registo de valores, foi implementado um sis-tema de instrumentação com capacidade de medir as temperaturas do ar e do ciclo frigo-rífico e as pressões. Foi utilizado outro sistema de aquisição para a medição do consumo energético e a vibração do compressor. Os ensaios foram realizados com as câmara aber-tas e com as câmaras fechadas, dentro e fora das condições nominais de carga de fluido frigorigéneo.
Na análise dos resultados, verificou-se que, para ambos os modos, com a diminu-ição da carga de fluido frigorigéneo a temperatura de condensação, de evaporação e de subarrefecimento diminuiu. Já a temperatura de sobreaquecimento aumentou forma signi-ficativa. A potência do compressor também diminuiu com a redução da carga, assim como a capacidade de arrefecimento/aquecimento e os coeficientes EER/COP. A vibra-ção no compressor do ciclo frigorífico também foi medida, verificando-se variações no espectro de frequências para diferentes cargas de fluido frigorigéneo. A vibração do com-pressor, a temperatura à saída do tubo capilar e a temperatura de sobreaquecimento apre-sentam variações significativas, podendo ser bons indicadores no diagnóstico de falta de fluido frigorigéneo do equipamento.
The concern with the environment is growing, due to the increase of global war-ming and the depletion of the ozone layer. The purchase of air conditioning equipment has also been increasing, as the amount of equipment used. One of the most common faults in this type of equipment is refrigerant leakage, and many of the equipment used today have gases that contribute negatively to the environment. Therefore, the deve-lopment of methods to identify this type of failure has been increasingly studied. In this work, an installation for testing split air conditioners was designed and built, for different refrigerant load conditions. The installations consist of a chamber built with thermally insulating material and two fans with adjustable volume flow rate. A sys-tem was also built to collect or inject refrigerant, simulating a failure situation. For mo-nitoring and recording of values, an instrumentation system was implemented with the ability to measure the air and refrigerant cycle temperatures and pressures. Another ac-quisitions system was used for the measurement of energy consumption and compressor vibration. The tests were performed with the chambers open and with the chambers clo-sed, in and out of the nominal refrigerant load conditions. Analysing the results, it was found that, for both modes, with the decrease of the refrigerant load, the condensing, evaporating and subcooling temperatures decreased. The superheat temperature, on the other hand, increased significantly. The compressor power also decreases with the load reduction, as does the cooling/heating capacity and EER and COP coefficients. The vibration in the compressor of the refrigeration cycle was also measured, and variations in the frequency spectrum were verified for different refrigerant loads. The vibration of the compressor, the temperature at the capillary tube outlet and the overheating temperature show significant variations, and may be good indicator in diagnosing the lack of refrigerant in the equipment.
The concern with the environment is growing, due to the increase of global war-ming and the depletion of the ozone layer. The purchase of air conditioning equipment has also been increasing, as the amount of equipment used. One of the most common faults in this type of equipment is refrigerant leakage, and many of the equipment used today have gases that contribute negatively to the environment. Therefore, the deve-lopment of methods to identify this type of failure has been increasingly studied. In this work, an installation for testing split air conditioners was designed and built, for different refrigerant load conditions. The installations consist of a chamber built with thermally insulating material and two fans with adjustable volume flow rate. A sys-tem was also built to collect or inject refrigerant, simulating a failure situation. For mo-nitoring and recording of values, an instrumentation system was implemented with the ability to measure the air and refrigerant cycle temperatures and pressures. Another ac-quisitions system was used for the measurement of energy consumption and compressor vibration. The tests were performed with the chambers open and with the chambers clo-sed, in and out of the nominal refrigerant load conditions. Analysing the results, it was found that, for both modes, with the decrease of the refrigerant load, the condensing, evaporating and subcooling temperatures decreased. The superheat temperature, on the other hand, increased significantly. The compressor power also decreases with the load reduction, as does the cooling/heating capacity and EER and COP coefficients. The vibration in the compressor of the refrigeration cycle was also measured, and variations in the frequency spectrum were verified for different refrigerant loads. The vibration of the compressor, the temperature at the capillary tube outlet and the overheating temperature show significant variations, and may be good indicator in diagnosing the lack of refrigerant in the equipment.
Description
Keywords
Ar condicionado split Ciclo frigorífico Fluido frigorigéneo Fugas Vibração