Assessing the energy efficiency of irrigation pump systems

G. Popov1*, K. Klimentov1, B. Kostov1, I. Ivanov1

Department of Heat, Hydraulics and Environmental Engineering, Faculty of Agriculture and Industry, University “Angel Kanchev” of Ruse, 8 Studentska str., 7004 Ruse, Bulgaria

(Manuscript received 20 June 2023; accepted for publication 15 August 2023)

Abstract. The operating modes of pump units play a crucial role in determining the energy consumption of irrigation systems. Thus, the necessity of performing qualitative and quantitative assessments of the energy efficiency of such systems is of significant importance. This paper proposes a method, newly established by authors, for accomplishing such an assessment. Using dimensionless criteria from Dimensional Analysis (as outlined in earlier publications), we propose a method to determine the specific energy consumption (ev) for a given flow rate, regulated by either VFD or throttle flow control, which are commonly used in practice. The specific relative energy consumption is depicted as an exponential relationship with four other criteria, each expressed relatively. The exponents are determined depending on the type of pump system flow rate control method applied. This energy exponent is also expressed in the dimensionless form obtained depending on the main parameters of the pump and pipe system. In this regard, two energy efficiency coefficients are introduced – of the pump and pipe system . Results obtained after performing numerical studies of a pump system, consisting of Bulgarian double-suction pumps, are presented.