Energy Consumption Reduction of a Chiller Plant by Adding Evaporative Pads to Decrease Condensation Temperature

Abstract

The high energy consumption of cooling systems justifies the need for strategies to increase the efficiency of the facilities, in order to reduce the related CO2 emissions. This study aims to improve the performance and reduce the energy consumption of an 8.6 MW air cooled chiller. This installed capacity is biased due to the screw compressors, of 2.98 Energy Efficiency Ratio (EER) at full load (characteristics provided by the manufacturer). The chiller unit has been modified by placing evaporating cooling pads before the condensing coils. The chiller has been monitored for three months, recording over 544,322 measurements (5 min-step data), with and without the evaporative cooling pads, to assess the performance. Data comparison has been done by selecting two days (with and without evaporative panels) with the same health care load and temperatures. Implementing the proposed strategy yields an improvement in the European Seasonal Energy Efficiency Ratio (ESEER) from 3.69 to 4.83, while the Total Equivalent Warming Impact (TEWI) decreases about 1000 tCO2. Energy savings of up to 32.6 MWh result into a payback period lower than 2 years.

Direct evaporative cooling from wetted surfaces: Challenges for a clean air conditioning solution

“…A trend towards hybrid systems with DEC can also be seen in the air condensing units of chiller plants (Rey‐Martínez et al, 2020) and in dry cooling towers (S. He, Guan, Gurgenci, Hooman, Lu, & Alkhedhair, 2014; S. He et al, 2015). In these applications, evaporative cooling pads are being incorporated to precool the working air towards its WBT during particularly harsh outdoor conditions.…”

“…Similarly, for a split air conditioner including a DEC pad on the condenser, the expected payback period was 2.87 years (Ketwong et al, 2021). Rey‐Martínez et al (2020) installed corrugated cellulose rigid media pads at the inlet of the air condensing units of a 8.9 MW chiller plant at a hospital, which enabled over 3700 € yearly savings, resulting in a payback period of less than 2 years.…”

“…Precooling air before air condensing units can considerably improve the EER of conventional vapor compression systems. Installing DEC pads at the air condensing unit inlet of a 8.9 MW chiller plant with 2.98 EER resulted in a reduction in the total equivalent warming impact of the chiller plant of 1000 tons CO 2 and energy savings of up to 32.6 MWh for a 15‐year study (Rey‐Martínez et al, 2020).…”

Energy Performance of a University Building for Different Air Conditioning (AC) Technologies: A Case Study

“…The energy simulation of the building is the most used tool for the energy performance assessment of buildings due to the use of EnergyPlus calculation engine and the Transfer Function (TF) [31][32][33] (Equation (1)):…”

Experimental Investigation of a Split Air Conditioning Using Condensate as Direct Evaporative Cooling

“…Many scholars have done experimental research on evaporative cooling system combined with condenser using different type of evaporative pad. Martínez et al, [20] has been modified the chiller unit by placing evaporative cooling pads before the condenser to improve performance and reduce the energy consumption of an 8.6 MW air cooled chiller. Zaidan et al, [21] presented the performance enhancement by adding a wet pad in Vapor Compression Cooling System.…”