A steady-state model for a centralized cooling system is developed to enable proper provisioning of cooling resources in capital intensive projects such as data centers. The model resolves the energy equations for a cooling tower and a centralized water-cooled chiller simultaneously. It requires inputs that are readily available to the design engineer. The user inputs are the ambient conditions...

A study was conducted to determine the effects of treating and reusing poultry chiller water in a commercial poultry processing facility. Broiler carcasses and chiller water were obtained from a commercial processing facility which had recently installed a TOMCO Pathogen Management System to recycle water in sections 2 and 3 of two 3-compartment chillers. In this system, reused water is blended...

Although water-cooled chillers are more energy efficient than air-cooled chillers, a majority of chilled water systems use air-cooled chillers. In cold weather climates, air-cooled chillers are capable of functioning in low ambient temperatures with few operational concerns, where as water-cooled chiller systems must be equipped to prevent cooling tower freezing. The integrated chiller system a...

To detect degradation in energy efficiency of a chiller in a chiller plant, a multivariate Gaussian mixture model is applied. This classification technique was selected to take advantage of an expected correlation between measurable state variables and equipment and operation specifications and system control targets. The hidden variable is the faultiness of the chiller and can take on one of t...

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A mathematical model describing the behaviors of current commercialized silica gel-water adsorption chillers is presented in this study. Comparing with the previous study, this model comprises (i) a realistic representation of the thermal mass of the associated piping materials and fins; (ii) a distributed modeling of the reactor bed for the sorption processes. The model is demonstrated on a tw...

For simulation of centrifugal chiller system with differential algebraic equations (DAEs), consistent initial conditions are difficult to obtain due to the two-phase refrigerant cycle and the connections between several components. Existing rigorous initialization methods are generally not easy to apply and not suitable for the particular problem of centrifugal chiller simulation, such as the s...

In this paper, the transient model of a water-cooled centrifugal chiller is developed in Modelica with Dymola and the TLK/IfT Library (TIL). The centrifugal compressor is modeled in detail based on the turbomachinery theory. The chiller capacity control is achieved by the combination of variable inlet guide vane (VIGV) and variable speed drive (VSD). The shell-and-tube heat exchangers are discr...

A dynamic model for the simulation of a new single-effect water/lithium bromide absorption chiller is developed. The chiller is driven by two distinct heat sources, includes a custom integrated falling film evaporator-absorber, uses mixed recirculation and is exclusively cooled by the ambient air. Heat and mass transfer in the evaporator-absorber and in the desorber are described according to a...