scholarly journals Modeling and optimization of a chilled-water cooling system with multiple chillers

2020 ◽  
pp. 328-328
Author(s):  
Jiamin Du ◽  
Shuhong Li ◽  
Xinmei Li
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Cooling System ◽  
Support Vector ◽  
Water Cooling ◽  
Parallel Operation ◽  
Total Energy Consumption ◽  
Modeling And Optimization ◽  
Chilled Water ◽  
Water Cooling System

In order to reduce energy consumption of the centralized chilled-water cooling system in large buildings, a dynamic control strategy was proposed for cooling plants by modeling and optimization. Combined with the chilled water flow model, this paper analyzed the parallel operation characteristics of the chillers and takes the load distribution as one of the control parameters. Based on the measured data of a typical cooling system that has undergone preliminary energy-saving transformation, the residual neural network (ResNet) is applied to model the relationship among energy consumption, controllable parameters and environmental parameters, and the ResNet outperforms multi-layer perceptron (MLP) and support vector regression (SVR). To minimize the total energy consumption, the gray wolf optimizer (GWO) was introduced to optimize the controllable variables of the cooling system. Compared with the energy consumption before optimization, the simulation energy consumption after optimization decreased 10.45% on average, while the energy saving rate is only 7.9% with equal chilled water supply temperature of parallel chillers.

Characterization of an Isolated Hybrid Cooled Server With Failure Scenarios Using Warm Water Cooling

2017 ◽  
Author(s):  
Uschas Chowdhury ◽  
Manasa Sahini ◽  
Ashwin Siddarth ◽  
Dereje Agonafer ◽  
Steve Branton
Keyword(s):  
Energy Consumption ◽  
Data Centers ◽  
Cooling System ◽  
Warm Water ◽  
Alternative Methods ◽  
Inlet Temperature ◽  
Cooling Efficiency ◽  
Water Cooling ◽  
Liquid Cooling ◽  
Total Energy Consumption

Modern day data centers are operated at high power for increased power density, maintenance, and cooling which covers almost 2 percent (70 billion kilowatt-hours) of the total energy consumption in the US. IT components and cooling system occupy the major portion of this energy consumption. Although data centers are designed to perform efficiently, cooling the high-density components is still a challenge. So, alternative methods to improve the cooling efficiency has become the drive to reduce the cooling cost. As liquid cooling is more efficient for high specific heat capacity, density, and thermal conductivity, hybrid cooling can offer the advantage of liquid cooling of high heat generating components in the traditional air-cooled servers. In this experiment, a 1U server is equipped with cold plate to cool the CPUs while the rest of the components are cooled by fans. In this study, predictive fan and pump failure analysis are performed which also helps to explore the options for redundancy and to reduce the cooling cost by improving cooling efficiency. Redundancy requires the knowledge of planned and unplanned system failures. As the main heat generating components are cooled by liquid, warm water cooling can be employed to observe the effects of raised inlet conditions in a hybrid cooled server with failure scenarios. The ASHRAE guidance class W4 for liquid cooling is chosen for our experiment to operate in a range from 25°C – 45°C. The experiments are conducted separately for the pump and fan failure scenarios. Computational load of idle, 10%, 30%, 50%, 70% and 98% are applied while powering only one pump and the miniature dry cooler fans are controlled externally to maintain constant inlet temperature of the coolant. As the rest of components such as DIMMs & PCH are cooled by air, maximum utilization for memory is applied while reducing the number fans in each case for fan failure scenario. The components temperatures and power consumption are recorded in each case for performance analysis.

The Research of Energy-Saving in Air Conditioning Water Cooling System by Frequency Conversion Pump and Constant Pressure Control

2013 ◽  
Vol 446-447 ◽  
pp. 1207-1210 ◽  
Author(s):  
Hong Jie Wang ◽  
Fang Wang ◽  
Yuan Yuan Huang ◽  
Liang Zhang
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Frequency Conversion ◽  
Constant Pressure ◽  
Cooling System ◽  
Branch Pipe ◽  
Pressure Control ◽  
Water Cooling ◽  
Water Pump ◽  
Water Cooling System

The main research point is analysis of energy conservation on water cooling system in air conditioning engineering in this paper. After discussing the running characteristics for frequency water pump controlling variable speed and changing the flow. Then the cooling system adopts the new control method that constant branch pipe pressure difference in the most unfavorable end, and the water pump in parallel configuration, combined with the frequency conversion technology. At last from the experiment data and the actual test of the water cooling system, the energy-saving effect with variable pump of constant pressure control is validated.

scholarly journals Optimized Design of Diesel Generators Based Chilled Water Cooling System for Intelligent Hospitals and Hotels

2020 ◽  
Vol 9 (3) ◽  
pp. 1649-1656
Keyword(s):  
Carbon Dioxide ◽  
Co2 Emissions ◽  
Cooling System ◽  
Load Management ◽  
Water Cooling ◽  
Cooling Systems ◽  
Saving Ratio ◽  
Chilled Water ◽  
Diesel Generators ◽  
Water Cooling System

For the intelligent applications like Hotels and Hospitals, there is requirement of efficient chilled water system in terms of energy consumption reduction, cost minimization, reduction in Carbon Dioxide (CO2 ) emissions. As the loads in hotels and applications increases, the performances of water cooling systems becomes the worst that leads to excessive consumption of energy and emission of CO2 , thus it needs the efficient load management strategies as well. In this paper, we first analysed the challenges of energy and CO2 efficiency of water cooling system in the intelligent hospitals and hotels from systematic point of view and then introduced the effective scheduling strategies for both hotel and hospitals. Further, the key focus in this paper is to design water cooling system using the diesel generators by considering the real time applications hospitals and hotels. Since the coolant temperature is having the significant effects on the performance of cooling engine and the CO2 emissions, therefore we introduced the diesel generators with coolant system to investigate such effects. For the cold water supply load management, we designed the Particle Swarm Optimization (PSO) based scheduling strategy at last. This paper exhibits the plan and its simulation results that analysed in terms of ESR (Energy Saving Ratio), CSR (Cost Saving Ratio), and CRR (Carbon dioxide Reduction Ratio) for the Internal Combustion Engine (ICE) capacity on heating and cooling systems.

scholarly journals Energy analysis using carrier HAP program and Deep Lake Water Cooling (DLWC) feasibility analysis for Ryerson University

2021 ◽  
Author(s):  
Md. Ziaur Rahman
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Lake Water ◽  
Building Energy ◽  
Energy Simulation ◽  
Base Case ◽  
Water Cooling ◽  
Ghg Emission ◽  
Deep Lake ◽  
Total Energy Consumption

The objective of this project is to determine the total annual energy summary in terms of cost and Greenhouse Gas (GHG) emission of 16 buildings at Ryerson University (RU). In addition, the Deep Lake Water Cooling (DLWC) feasibility analysis of RU is another objective of this project in terms of total energy consumption and amount of gas emission reduction. The total audit area of RU was 86% of the total campus area. Building energy simulation program, Carrier HAP (Hourly Analysis Program), has been used to make an integrated evaluation of building energy consumption. An energy simulation involves hour-by-hour calculations for all 8,760 hours in a year. In this project, an energy audit was conducted for the 16 existing buildings to establish the base case model, "Ryerson University", to determine its annual energy consumption across all usage. There are two sources of energy used at RU. Electricity uses for lighting, plug load, miscellaneous and cooling, and remote steam is used for cooling and heating. For the base case model, total energy consumption was 251 TJ. To reduce the total energy consumption of the base case model, HVAC systems were investigated to analyze their energy-based performance and impact on the GHG emission. There is no Heat Recovery Ventilation (HRV) system coming from the investigation of HVAC system. The sensitivity analysis was conducted using HRV system with air system. By using HRV system with air system, total of 5.6% energy would be saved for cooling and 76% energy would be saved for heating of RU. The energy intensity was determined to be 1.04 GJ/m² only for 16 buildings of RU and comparatively it is lower than other universities in Canada which have a range of 1.64 GJ/m² to 2.26 GJ/m². In the DLWC system, cool lake water at 4°C was used for building air conditioning. To reduce the cooling energy costs, DLWC system was considered as an alternative chilled water source. The Rogers Business Building (RBB) already has DLWC system. For DLWC system, chilled water was served by Enwave to the RBB. According to base case analysis of the RBB with conventional chillers, the electricity consumption was 924594 kWh for RBB due to chillers. With the implementation of DLWC system for the rest of the 15 buildings, total energy saving due to cooling would be 89.2% and GHG emission reduction would be 89% for CO₂, 70% for NOx and 70.4% for SOx due to elimination of chillers.

Multi-Objective Optimization Analysis of Motor Cooling System in Articulated Dump Truck

2011 ◽  
Vol 383-390 ◽  
pp. 4715-4720
Author(s):  
Yan Zhang ◽  
Yan Hua Shen ◽  
Wen Ming Zhang
Keyword(s):  
Field Distribution ◽  
Cooling System ◽  
Dump Truck ◽  
Water Cooling ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Pareto Optimal Set ◽  
Temperature And Pressure ◽  
Water Cooling System ◽  
Optimal Set

In order to ensure the reliable and safe operation of the electric driving motor of the articulated dump truck, water cooling system is installed for each motor. For the best performance of the water cooling system, not only the heat transfer should be enhanced to maintain the motor in relatively low temperature, but also the pressure drop in the water cooling system should be reduced to save energy by reducing the power consumption of the pump. In this paper, the numerical simulation of the cooling progress is completed and the temperature and pressure field distribution are obtained. The multi-objective optimization model is established which involves the cooling system structure, temperature field distribution and pressure field distribution. To improve the computational efficiency, the surrogate model of the simulation about the cooling process is established based on the Response Surface Methodology (RSM). After the multi-objective optimization, the Pareto optimal set is obtained. The proper design point, which could make the average temperature and pressure drop of the cooling system relative desirable, is chosen from the Pareto optimal set.

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