Akıllı endüstriyel altyapılar için enerji optimizasyonu: Su şebekesi örneği
Energy optimization for smart industrial infrastructure: Water supply network example
Yazar: HUSSEIN MOHAMMED HUSSEIN QASIM AL-SANABANI
Danışman: DR. ÖĞR. ÜYESİ MURAT İSKEFİYELİ
Sakarya Üniversitesi / Fen Bilimleri Enstitüsü / Bilgisayar Mühendisliği Ana Bilim Dalı / Bilgisayar Mühendisliği Bilim Dalı
Derece: Doktora, 2024
Konu: Bilgisayar Mühendisliği Bilimleri-Bilgisayar ve Kontrol = Computer Engineering and Computer Science and Control

Özet:
Su dağıtım sistemlerinin verimli işletimi için özellikle enerji maliyetlerinin azaltılması ve su talebinin sürekli olarak karşılanması büyük öneme sahiptir. Bu amaçla, enerji maliyetlerini minimize etmek ve su pompalama istasyonlarının işleyişini optimize etmek için matematiksel modeller kullanılır. Bu bağlamda, üç farklı çalışma sunulmuştur:
İlk çalışma, su dağıtım sistemlerindeki (bir pompa ve bir depo) pompalama için kullanılan enerji maliyetini azaltmayı hedeflemektedir. Bu amaçla, SDPA (Sadeleştirilmiş Dinamik Programlama Algoritması) adlı yeni bir algoritma geliştirilmiştir. SDPA, geleneksel su seviyesi kontrolü (CWLC) yaklaşımına kıyasla daha fazla enerji tasarrufu sağlayabilir. Özellikle Sakarya ilindeki bir su dağıtım sistemi üzerinde yapılan uygulamalarda, SDPA'nın enerji maliyetinde %12'lik bir tasarruf elde edebildiği görülmüştür.
İkinci çalışmada, SDPA yaklaşımının daha geniş bir kullanım alanı sağlayacak şekilde optimize edilerek OSDPA (Optimal Sadeleştirilmiş Dinamik Programlama Algoritması) adlı yeni bir algoritma geliştirmiştir. OSDPA, çok aşamalı (kaskad) sistemleri optimize etmek için kullanılabilir ve özellikle karmaşık pompalama sistemlerinde etkili sonuçlar verir. Örnek bir vaka çalışması olarak Türkiye'deki Sakarya Su ve Kanalizasyon İdaresi'ne ait çok aşamalı pompa sistemleri incelenmiş ve OSDPA yaklaşımının enerji maliyetlerinde önemli tasarruflar sağladığı gösterilmiştir.
Üçüncü çalışma ise E-SDPA (Genişletilmiş Sadeleştirilmiş Dinamik Programlama Algoritması) adlı bir algoritmayı tanıtmaktadır. Bu algoritma, çoklu pompa istasyonları için optimize edilmiştir ve enerji maliyetlerini azaltmak için farklı zaman dilimlerindeki yükleri yönetmede etkili bir şekilde çalışır. Çalışmalar, E-SDPA'nın geleneksel su seviyesi kontrolü yaklaşımıyla karşılaştırıldığında enerji maliyetlerinde %20'lik bir tasarruf sağlayabileceğini göstermektedir.
Bu üç çalışma, su dağıtım sistemlerinde enerji tasarrufunu artırmak için geliştirilmiş algoritmalar sunarak elektrik kaynaklarının daha sürdürülebilir bir şekilde yönetilmesine katkı sağlar. Sonuç olarak bu çalışmalar, su dağıtım sistemlerindeki pompalama enerji maliyetlerini azaltmak için geliştirilen SDPA, OSDPA ve E-SDPA algoritmalarının, enerji tasarrufu sağlamak ve su talebini sürekli olarak karşılamak isteyen su dağıtım şirketleri için önemli araçlar olduğunu göstermektedir.

Abstract:
Inefficient operation of pump stations leads to ineffective pump systems. It is evident that the primary expense in pumping systems is the energy cost, constituting the largest portion of the overall expenditure.
To mitigate energy expenses, load-shifting techniques contributing to water demand management can be employed. These approaches involve strategies to shift electrical loads to off-peak hours, utilizing tank capacity to reduce pumping costs in water distribution systems.
Ensuring the optimal functioning of water distribution systems is crucial, particularly when aiming to improve the performance of water pumping stations for the dual purpose of lowering energy costs and consistently meeting water demand. Mathematical models are employed to minimize energy expenses and optimize the operation of water pumping stations in pursuit of this objective. In this context, three distinct studies have been presented:
The first study aims to reduce the energy cost associated with pumping in water distribution systems (one pump and one reservoir). For this purpose, a new algorithm called Simplified Dynamic Programming Algorithm (SDPA) has been developed. SDPA can provide more energy savings compared to the Conventional Water Level Control (CWLC) approach.
SDPA stands out as an algorithm that aims to shift peak loads to the night by simply optimizing the pumping schedule, without changing the equipment and physical conditions in existing drinking water distribution systems. 
The simulation and application results have demonstrated that the SDPA approach offers lower pump operating frequency and reduced pumping costs compared to the CWLC and Improved Dynamic Programming Algorithm (IDPA) approaches. By implementing SDPA, the optimal amount of savings achievable solely through the optimization of the pumping schedule has been attained. In the simulation environment, it was observed that the maximum savings achievable through the optimization of only the pumping schedule is 11.97%, and this amount has translated into a 11.85% savings in operational costs reflected in electricity bills with the implementation of SDPA. 
With the implementation of SDPA, it has been possible to reduce the decision period encountered in the IDPA approach, addressing the issue of increased pump operating frequency. This has resulted in a significant reduction of approximately 72% in the number of pump start-stop decisions. The advantages derived from the reduction in pump start-stop cycles include: extended pump-motor lifespan, increased maintenance intervals, avoidance of high currents during startup (inrush current), and a decrease in energy consumption compared to nominal power due to the reduction in inrush current.
The second study optimizes the SDPA approach to create a new algorithm called Optimal Simplified Dynamic Programming Algorithm (OSDPA) that can have a broader range of applications. OSDPA can be used to optimize multi-stage (cascade) systems and yields effective results, especially in complex pumping systems. As an example case study, multi-stage pump systems belonging to the Sakarya Water and Sewerage Administration in Turkey were examined, and the OSDPA approach was shown to provide significant energy cost savings.
According to OSDPA, it is emphasized that in order to optimize the entire system, the system must first be divided into subsystems and optimized step by step from the top level to the bottom level (main source). In multistage pump systems, when only the last stages are optimized, a reduction in the energy cost of the pumps in the lower stages until reaching the main water supply has been observed, even if no optimization has been made in the first stages.
Despite the complexity of cascade-structured systems, OSDPA has provided lower pump operating frequency and significant energy savings compared to CWLC. OSDPA achieves this by optimizing the operating schedules of pumps A, B, and C in the water supply system, ensuring the maximum shift of the highest-cost electricity consumptions to other tariff time slots as much as possible. This underscores the success of OSDPA in cascade-structured water supply systems. When compared to Conventional Water Level Control (CWLC), under specified conditions and without any physical equipment improvements, OSDPA offers the best optimization results achievable solely through load shifting. OSDPA can deliver energy cost savings of 39%, 41%, and 24% for pumps C, B, and A, respectively, in the system.
The third study introduces an algorithm called Extended Simplified Dynamic Programming Algorithm (E-SDPA). E-SDPA is an algorithm developed to optimize multi-pump water stations and effectively manages loads at different time intervals to reduce energy costs. E-SDPA is an adaptation of the SDPA algorithm for use in multiple pump stations, which typically consist of a tank and multiple pumps.
The simulation results conducted in the study field clearly demonstrate that the E-SDPA approach provides lower pump operating frequency and reduced pump costs compared to CWLC approaches. By using E-SDPA, the maximum savings achievable through the optimization of pump operating times alone have been attained. This savings amount was determined to be 20.69% in our simulations.
As a result of implementing E-SDPA, the number of pump start-stop cycles has been reduced by 77% compared to the CWLC approach. The advantages of reducing pump start-stop cycles include an extended pump-motor lifespan, extending maintenance periods, avoidance of high inrush currents during startup, and a decrease in energy consumption compared to nominal power due to the reduction in inrush current.
These three studies present novel algorithms to reduce the energy costs of water pumping systems. Each of SDPA, OSDPA, and E-SDPA demonstrates lower pump operating frequency and costs compared to traditional methods such as CWLC. Additionally, practical advantages like the lightweight nature of these algorithms and their integration with Programmable Logic Controllers (PLC) have been emphasized.
These three studies present that in multistage pump systems, when only the last stages are optimized, a reduction in the energy cost of the pumps in the lower stages until reaching the main water supply has been observed, even if no optimization has been made in the first stages.
These three studies offer developed algorithms to enhance energy savings and efficiency in water distribution systems, contributing to the more sustainable management of electricity resources. As a result, these studies demonstrate that the SDPA, OSDPA, and E-SDPA algorithms developed to reduce pumping energy costs in water distribution systems are essential tools for water distribution companies seeking to achieve energy savings and consistently meet water demand.