Optimum Design and Operation of an HVAC Cooling Tower for Energy and Water Conservation

Abstract

Abstract:The energy consumption increase in the last few years has contributed to developing energy efficiency policies in many countries, the main goal of which is decreasing CO 2 emissions. One of the reasons for this increment has been caused by the use of air conditioning systems due to new comfort standards. In that regard, cooling towers and evaporative condensers are presented as efficient devices that operate with low-level water temperature. Moreover, the energy consumption and the cost of the equipment are lower than other systems like air condensers at the same operation conditions. This work models an air conditioning system in TRNSYS software, the main elements if which are a cooling tower, a water-water chiller and a reference building. The cooling tower model is validated using experimental data in a pilot plant. The main objective is to implement an optimizing control strategy in order to reduce both energy and water consumption. Furthermore a comparison between three typical methods of capacity control is carried out. Additionally, different cooling tower configurations are assessed, involving six drift eliminators and two water distribution systems. Results show the influence of optimizing the control strategy and cooling tower configuration, with a maximum energy savings of 10.8% per story and a reduction of 4.8% in water consumption.

Formulation of Coefficient of Performance Characteristics of Water-cooled Chillers and Evaluation of Composite COP for Combined Chillers

“…In the study of cooling towers, simple calculation methods have been proposed for determining the cooling water temperature, power consumption of cooling tower fan, and cooling water consumption using theoretical analysis and a computational model [8]. Experimental studies have also been carried out to extend the computational model.…”

“…A study using the number of transfer units (NTU) has been proposed for calculating the cooling water temperature of a cooling tower [8], but in this study, we used Tower Performance Factor (TPF) instead of NTU. Here, TPF is equal to NTU divided by ratio of cooling water volume (L: kg/h) to blast volume (G: kgDA/h; L/G).…”

Optimization of BuildingsEnergy Consumption by Designing Sliding Mode Control for Multizone VAV Air Conditioning Systems

“…The basic laws based on the pressure independent and pressure-dependent terminal unit of VAV were designed, then the Elman neural network with control was proposed. The authors in [21] presented models of an air conditioning system, the fundamental components of which were a cooling tower, a water-water chiller and a reference building. The model of the cooling tower was validated by using exploratory information in a pilot plant.…”

Heat Transfer Enhancement of the Air-Cooling Tower with Rotating Wind Deflectors under Crosswind Conditions

“…Water quantity determines the type of cooling towers used in a power plant. An air conditioning system was modeled in TRNSYS software [1] for energy and water conservation; the results showed the benefits of optimizing the control strategy and cooling tower configuration with a maximum energy savings and water reduction of 10.8% and 4.8%, respectively [2]. To protect water resources, significant conservation is obtained by applying an indirect air-cooling tower as shown in References [3,4].…”