OPERATION ANALYSIS OF A INDUSTRIAL COOLING SYSTEMS WITH VARIABLE SPEED AIMING THE EFFICIENCY ENERGY A. B. Moreira, C. R. Shmidlin Jr., R. T. S. Pontes, C. A. Monteiro, T. N. C. Neto. Federal University of Ceará. Laboratório de Eficiência Energética em Sistemas Motrizes. Department of Electrical Engineering, Caixa Postal 6001 - Campus do Pici- Bloco 705 - 60.455-760 Fortaleza - CE – Brasil. adson@dee.ufc.br , celso@dee.ufc.br , ricthe@dee.ufc.br , tomaz@dee.ufc.br , almir@ufc.br . Abstract – The paper relates the simulation and analysis of the behavior efficiency industrial cooling system’s in a constant speed compared with a variable speed system from inverter PWM sinusoidal, aiding to control fluid volumetric flow rate and pressure and consequently save energy. Index Terms— Cooling system, efficiency, motor, energy, PWM inverter, save. I. INTRODUÇÃO The scarcity of natural resources, the economic picture of stagnation and a competitive process for which were the society in the last times, have reduced costs for better applying capital, it results save energy in the sectors industrial, commercial and residential. In the industry, it this comes being done from reducing energy losses in the productive process, specifying the equipments with maximum efficiency and operating them next to this condition. The fans and the hydraulical pumps are used more at the industry in some applications. They are used about 65 % of the industry electric energy is consumed by electric [2]. The fans are common in industrial processes, such as: blast furnaces in the siderurgical ones, installations of boilers, sprays of coal, burners and in many other applications [1]. This work is one of activities released by LAMOTRIZ (Laboratório de Eficiência Energética em Sistemas Motrizes) with objective in energy efficiency of systems’s force motor in industrial consumers. The main objective of this work is to analyze the operation the variable speed of a system of industrial cooling, shaping since the hydraulical part until the electric part, aiming at the efficiency in the consumption of the electric energy for the diverse situations of demand of an installation. II. COOLING SYSTEM The industrial cooling system is composed for the installation of cooling and the group motor-fan, each one have a characteristic curve of load versus flow rate that, when it crossed, they determine the point of system operation. Some elements in the industrial cooling installation of the LAMOTRIZ are: suppressors of noise, expansion, reduction, curve, damper and centrifugal fan. A. Group of benches of cooling The centrifugal fan has an excellent point of operation that it determines flow rate, pressure and rotation, where its losses to flow are minimum. In the work the operation of a radial centrifugal fan analyzed, it is the most used in the industry, in Figure 1. The fan has an electric motor 2 hp, static pressure of 784 Pa and outflow of 1,67 m 3 /s and an inverter. Fig. 1. Photograph of experimental setup - LAMOTRIZ – UFC. Fig. 2. Photograph of experimental setup - LAMOTRIZ – UFC. In Figure 2, it is observed suction (the right) and the air discharge of the radial fan (left). The cooling system has acquisition of electric data and mechanical, amongst them: voltage, current, rotation of the motor, temperature of the motor and environment, pressure in the input and output of the fan and flow rate. In Figure 3, it is observed place of the sensors in the plant of used cooling.