Genetic Algorithms are employed to optimize the selection of chiller size in a multi-chiller central plant for arbitrary cooling load profiles. The objective of the optimization is to minimize life cycle (capital + operating) costs while keeping all chillers running in good part load conditions to avoid any surge of chillers. The approach has the capability of solving the combinatorial optimiza...

In this paper, a detailed simulation model of a solarpowered triple-effect LiBr–H2O absorption chiller is developed to supply both cooling and heating demand of a large-scale building, aiming to reduce the fossil fuel consumption and greenhouse gas emissions in building sector. TRNSYS 17 is used to simulate the performance of the system over a typical year. A combined energeticeconomic-environm...

The ventilation and air conditioning systems of large commercial buildings are typically driven by chilled-water plants with multiple chillers. Real-time optimization and sequencing of such plants is thus critical for building efficiency (AHRI 2011). Due to the complexity and cost for calibrating chiller plant in field operation, model-free control has become an attractive solution. In an earli...

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...

The chilled-water systems, mainly consisting of electric chillers and cooling towers, are crucial for the ventilating and air conditioning systems in commercial buildings. Energy efficient operation of such systems is thus important for the energy saving of commercial buildings. This paper presents an extremum seeking control (ESC) scheme for energy efficient operation of the chilled-water syst...

.............................................................................................................................. i List of Figures ................................................................................................................... vi List of Tables .................................................................................................................... i...

A data-driven approach is utilized to model a chiller plant that has four chillers, four cooling towers, and two chilled water storage tanks. The chillers have varying energy efficiency. Since the chiller plant model derived from data-driven approach is nonlinear and non-convex, it is not practical to solve it by using the traditional gradient-based optimization algorithm. A two-level intellige...

Recent improvements in HVAC control networking technologies together with an improved understanding of the nature of cooling loads in buildings offer enormous potential improvements in the cost effectiveness of district cooling plants. By carefully coordinating the district cooling plant design with a digital controls network to the loads served, the following economic advantages over tradition...

This thesis investigates the problem of regulating the temperature of a conditioned space using a Solar Assisted Air Conditioning Systems (SAACS) prototype located at Cabo Rojo, Puerto Rico. The SAACS Prototype consists of a 66 flat plate solar collector array with 115.4 m 2 of selective surface area, a 35 kW single-effect lithium-bromide absorption chiller, a 84 kW cooling tower, a 50 kW auxil...

We present a data mining approach to model the cooling infrastructure in data centers, particularly the chiller ensemble. These infrastructures are poorly understood due to the lack of “first principles” models of chiller systems. At the same time, they abound in data due to instrumentation by modern sensor networks. We present a multi-level framework to transduce sensor streams into an actiona...