We verified the utility of an oxygen economizer (Pendant Oxymizer) in assuring greater protection than nasal prongs against worsening of oxyhemoglobin resting desaturation (delta SaO2) induced by muscular exercise in 16 patients (ten with chronic obstructive pulmonary disease [COPD] and six with restrictive pulmonary disease). This worsening was quantified as desaturation surface accumulated wi...

Optimal building ventilation control is achieved combining demand controlled ventilation (DCV) and economizer control. The control instability during the transition processes between different control modes is among the major difficulties faced when combining DCV control with economizer control in applications. A robust control strategy, using “freezing”, gain scheduling, I-term reset and feedb...

As liquid oxygen represents a relevant burden on healthcare systems, different methods have been developed to reduce oxygen consumption, including economizers. The aims of the study were: 1) to evaluate the efficacy of an economizer device (Companion 5 Oxygen Saver) in a significant sample of patients, and 2) to perform cost-minimization analysis of the possible savings to be obtained using the...

The economizers are used for production of steam heating on en route ships. The economizers are producing steam in a heat exchange process from the ship’s main engine exhaust gas. Products of the incomplete combustion of the heavy fuel oil remaining in engines, passing the boiler, collect on the heat exchange surface of the economizer. When the incorrect assumptions are made for the boiler oper...

Article history: Received 28 October 2011 Accepted December, 5 2011 Available online 8 December 2011 Continuous generation of electricity of a power plant depends on the higher availability of its components/equipments. Higher availability of the components/equipments is inherently associated with their higher reliability and maintainability. This paper investigates the reliability, availabilit...

The air-side economizers have been developed as a major class of energy-saving equipment to enhance the energy efficiency of central air-conditioning systems by taking advantage of outdoor air during cool or cold weather. In current practice, the outdoor air damper is controlled to maintain either the maximum or minimum opening by comparing the outdoor air temperature/enthalpy with the setpoint...

The energy performance of radiant slab cooling relative to conventional air systems to be clarified for climates from cold and dry to very hot and humid. EnergyPlus simulations were used to compare the energy performance of 1) radiant slab cooling combined with a dedicated outdoor air system and 2) a variable air volume system. Simulation results show that the radiant slab system provided 10% t...

The impulse turbo expander (ITE) is employed to replace the throttling valve in the vapor compression refrigeration cycle to improve the system performance. An improved ITE and the corresponding cycle are presented. In the new cycle, the ITE not only acts as an expansion device with work extraction, but also serves as an economizer with vapor injection. An increase of 20% in the isentropic effi...

The current financial and economic programme in the Russian Federation is aimed at increasing energy efficiency all areas of society. most effective way boiler plant operation to improve technology deep heat recovery from heated flue gas chimney system hot-water boilers. physical essence this phenomenon consists cooling escaping high-temperature combustion products gaseous fuel, through contact...