Optimal Control Strategy for Ice-Storage System Based on Hourly Dynamic Load Simulation

2013 ◽  
Vol 671-674 ◽  
pp. 2515-2519
Author(s):  
Xue Mei Wang ◽  
Zhen Hai Wang ◽  
Xing Long Wu
Keyword(s):  
Optimal Control ◽  
Air Conditioning ◽  
Control Strategies ◽  
Storage System ◽  
Simulation Software ◽  
Ice Storage ◽  
Optimal Control Strategy ◽  
Air Conditioning System ◽  
Energy Plus ◽  
Load Simulation

This project aims to study the optimal control model of the ice-storage system which is theoretically close to the optimal control and also applicable to actual engineering. Using Energy Plus, the energy consumption simulation software, and the simple solution method of optimal control, researchers can analyze and compare the annual operation costs of the ice-storage air-conditioning system of a project in Beijing under different control strategies. Researchers obtained the power rates of the air-conditioning system in the office building under the conditions of chiller-priority and optimal contro1 throughout the cooling season. Through analysis and comparison, they find that after the implementation of optimal control, the annually saved power bills mainly result from non-design conditions, especially in the transitional seasons.

Optimization Control of Ice Storage Air-Conditioning System

2013 ◽  
Vol 655-657 ◽  
pp. 1492-1495
Author(s):  
Ting Wu ◽  
Gang Wu ◽  
Zhe Jing Bao ◽  
Wen Jun Yan
Keyword(s):  
Control Strategy ◽  
Air Conditioning ◽  
Particle Swarm Optimization Algorithm ◽  
Ice Storage ◽  
Optimal Control Strategy ◽  
Air Conditioning System ◽  
Control Scheme ◽  
Optimization Control ◽  
Building Cooling ◽  
Operation Cost

Ice storage air-conditioning system can bring benefits to power supplier and consumers for its advantage of shifting power consumption at peak hours during day to the off-peak hours at night. In this paper, we adopted an improved particle swarm optimization algorithm to develop an optimal control strategy for ice storage air-conditioning system with the aim of minimizing operation cost subject to various operational constrains. Comparing with the usual chiller-priority and ice-storage-priority control strategy, the proposed control scheme can not only meet the building cooling load but also achieve the minimum operation cost.

scholarly journals Utilizing the solar thermal ice storage system in improving the energy, exergy, economic and environmental assessment of conventional air conditioning system

2021 ◽  
Author(s):  
Mohamed Elhelw ◽  
Wael M. El-Maghlany ◽  
Mohamed Shawky Ismail ‎
Keyword(s):  
Energy Saving ◽  
Air Conditioning ◽  
Storage System ◽  
Water System ◽  
Maximum Energy ◽  
Ice Storage ◽  
Air Conditioning System ◽  
Air System ◽  
Alexandria City ◽  
Air Conditioning Systems

Abstract This paper introduces novel modification for conventional air conditioning systems through utilizing a thermal ice storage system integrated with solar panels. Alexandria and Aswan, cities in Egypt, are chosen to represent two climates for hot-humid and hot-dry climates respectively. The governing equations for both heat and mass transfer are theoretically solved. Exergy analysis is performed for the proposed solar-ice thermal storage system via determining exergy destruction on ice and solar components as well as the total destruction based on transient analysis. This study was carried out on two common types of air conditioning systems, an air handling unit and fan coil unit. Results showed that, solar-ice storage system is more effective approach in hot-humid climate than hot-dry climate and more efficient with all-water air conditioning system than with all-air conditioning system. The maximum energy saving is 205.16 GJ having a percent of 27.5% in August for all water system in case of Alexandria city and 224.67 GJ with a percent of 25.38% in August for all-water system in case of Aswan city. All air system simulation showed maximum energy saving of 175.05 GJ with a percent of 18.13 % in case of August for Alexandria and 175.45 GJ having a percentage of 17.43% in case of Aswan in August. Moreover, the all-water system achieved a reduction in CO2 emissions by 467 tons/year in Aswan city and 390 tons/year in case of Alexandria city. While these reductions decrease to be 435 and 353 tons/year when the all-air system used for the same two cities.

Ice Storage System Controls for the Reduction of Operating Cost and Energy Use

1998 ◽  
Vol 120 (4) ◽  
pp. 275-281 ◽  
Author(s):  
G. P. Henze ◽  
M. Krarti
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Energy Use ◽  
Storage Systems ◽  
Storage System ◽  
Operating Cost ◽  
Optimal Strategies ◽  
Excess Energy ◽  
Ice Storage ◽  
Optimal Control Strategy

Ice storage systems have the reputation of saving cost for operating building cooling plants by appropriately recognizing time-of-use incentives in the utility rate structure. However, many systems can consume more electrical energy than a conventional cooling plant without ice storage. This excess energy problem is illustrated in this paper by a simplified cooling plant model employed in a simulation environment that allows the assessment of the control performance of various conventional and optimal strategies. The optimal control strategy of minimizing operating cost only is introduced and subsequently is modified to allow the simultaneous consideration of operating cost and energy consumption. This proposed optimal control strategy could be valuable if ice storage systems are to stand on their own merits in a deregulated utility environment. Due to the lack of demand charges under real-time pricing, even small energy penalties and their associated excess energy cost may jeopardize the feasibility of the ice storage system.

Parametric Study of a Simplified Ice Storage Model Operating Under Conventional and Optimal Control Strategies

Solar Energy ◽  
2002 ◽  
Author(s):  
Gregor P. Henze
Keyword(s):  
Optimal Control ◽  
Control Strategies ◽  
Storage System ◽  
Operating Cost ◽  
Load Forecasting ◽  
Cost Savings ◽  
Ice Storage ◽  
Storage Losses ◽  
Constant Proportion ◽  
The Impact

A simplified ice storage system model was developed in which the icemaking mode is reflected by a higher power consumption per unit cooling than in chilled-water mode. The performance of four control strategies for ice storage systems is evaluated. The four control strategies investigated are chiller-priority and constant-proportion as conventional, instantaneous controls, while storage-priority and optimal control represent sophisticated controls employing load forecasting. Six parameters were investigated with respect to their influence on the ice storage system performance: Storage losses, utility rate structures, rate periods, penalty for icemaking, storage capacity, and the impact of load forecasting. Optimal control was determined to provide maximal operating cost savings. The storage-priority control yields operating costs only slightly higher than those of optimal control. Chiller-priority control realized savings that were typically on the order of 50% of what is theoretically possible (optimal control). Constant-proportion control proved to be a simple control strategy yielding higher savings than chiller-priority, yet lower than storage-priority control.

Parametric Study of a Simplified Ice Storage Model Operating Under Conventional and Optimal Control Strategies*

2003 ◽  
Vol 125 (1) ◽  
pp. 2-12 ◽  
Author(s):  
Gregor P. Henze
Keyword(s):  
Optimal Control ◽  
Control Strategies ◽  
Storage System ◽  
Operating Cost ◽  
Load Forecasting ◽  
Cost Savings ◽  
Ice Storage ◽  
Storage Losses ◽  
Constant Proportion ◽  
The Impact

A simplified ice storage system model was developed in which the icemaking mode is reflected by a higher power consumption per unit cooling than in chilled-water mode. The performance of four control strategies for ice storage systems is evaluated. The four control strategies investigated are chiller-priority and constant-proportion as conventional, instantaneous controls, while storage-priority and optimal control represent sophisticated controls employing load forecasting. Six parameters were investigated with respect to their influence on the ice storage system performance: Storage losses, utility rate structures, rate periods, penalty for icemaking, storage capacity, and the impact of load forecasting. Optimal control was determined to provide maximal operating cost savings. The storage-priority control yields operating costs only slightly higher than those of optimal control. Chiller-priority control realized savings that were typically on the order of 50% of what is theoretically possible (optimal control). Constant-proportion control proved to be a simple control strategy yielding higher savings than chiller-priority, yet lower than storage-priority control.

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