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Showing 1 to 12 of 12 for “"Vapor compression systems"”.
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Potentials for COP increase in vapor compression systems
… different opportunities for COP increase in vapor compression systems: work recovery ejectors, condenser subcooling and increase of relative size of heat exchangers (HXs). Regarding work recovery ejectors, experimental results showed that the COP of the ejector system increased between 8.2% …
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Dynamic modeling, validation, and control for vapor compression systems
… process of model-based control design for vapor compression systems (VCSs), from nonlinear model development to linearization and control formulation. Addressing gaps in the previous literature, the equations behind each model and control approach are clearly stated and emphasis is placed …
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Model free real-time optimization for vapor compression systems
A vapor compression system's optimal input settings vary according to changes in environmental conditions. Tracking these optimal input trajectories can be challenging when insufficient information for a reliable system model is available. An alternative set of optimization approaches use system …
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Extremum seeking control of battery powered vapor compression systems for vehicles
… real-time energy optimization of battery powered vapor compression systems (VCS) for vehicles. Battery powered VCS are critical for maintaining passenger comfort in engine-off situations, and are especially important to long-haul truck drivers who sleep inside their vehicle overnight. However, one …
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TRANSIENT MODELING OF TWO-STAGE AND VARIABLE REFRIGERANT FLOW VAPOR COMPRESSION SYSTEMS WITH FROSTING AND DEFROSTING
… framework for the transient simulation of vapor compression systems. This framework contains a wide range of components and its modular nature enables an arbitrary cycle configuration to be analyzed. One of the highlights of this framework is the first-principles heat exchanger models with …
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Performance optimization of advanced vapor compression systems working with low-GWP refrigerants using numerical and experimental methods
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-05-01
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Experimental and numerical investigation of the design and control of vapor-compression systems with integration of two-phase ejectors for performance enhancement through expansion work recovery
… to improve the efficiency and capacity of vapor-compression refrigeration cycles by means of expansion work recovery has received significant attention in the past decade. Research has focused primarily on the design and performance of the ejector and the effect the ejector has on cycle …
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Cop and capacity improvement through work and heat recovery by using vortex tube
… possibility to replace the expansion valve of vapor compression systems with this low-cost device that can recover expansion work that would otherwise be lost in the isenthalpic throttling process. Most of the work on vortex tubes used for refrigeration have been numerical studies, and many of …
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Comparative study of advanced heat pumps
… are made to the more commonly applied vapor compression systems, including those using R-134a. The study examines the effect of thermal resistances between the device and the heat rejection or heat absorption space. A cool side temperature difference between 0 and …
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Dynamic Modeling and Advanced Control of Air Conditioning and Refrigeration Systems
… that captures the dynamics of a variety of vapor compression cycles in a form amenable to controller design. These models are highly nonlinear, and require a nonlinear control strategy to attain high performance over the entire operating envelope. To this end, a gain-scheduled control …
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Dynamic modeling and control of transcritical vapor compression system for battery electric vehicle thermal management
… is an increasing trend among vehicle systems such as aircrafts, heavy machinery, and civilian transportation. Battery electric vehicles (BEVs) are one such development that use a battery pack to generate electrical energy used to propel the vehicle and power its auxiliaries. However, …
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ENERGY SAVINGS AND THERMAL COMFORT OF SEPARATE SENSIBLE AND LATENT COOLING AIR-CONDITIONING SYSTEMS
Conventional air conditioning (AC) systems have limited control of sensible cooling and latent cooling capacities; therefore additional energy-consuming devices, i.e. electric heaters, are often used to reheat the conditioned air in order to provide thermal comfort for the building occupants. …