Customer benefit from the practical application of «7 = 2» initiative

Summary

The method of selecting pumping equipment by Life Cycle Cost (LCC) criterion – total cost of ownership is presented. The software that provides for calculating LCC criterion depending on the pump output is placed at www.7-2.su Web site. Submersible pumps are selected as a LCC calculation object because of their wide use at the sewage pumping stations under construction or subject to upgrade.

Key words

sewerage pumping station , impeller , electric power , submersible pump

Hydraulic calculation of group water intakes on underground wells equipped with pumps with variable speed drives

Summary

The use of variable speed drives at group water intakes on underground sources in water supply systems is aimed at saving electricity, ensuring efficient operation modes, improving the management engineering; however, without sufficient justification the desired result is not always effected. One of the reasons is the lack of calculation using an effective mathematical model that describes the movement of water in aquifers, wells, lift pipes and gathering mains, taking into account all the existing limitations, including the mode parameters while using variable speed drives in some or in all submersible pumps. The model is submitted in the form of an optimization task where the target function is the total power input of all the operating submersible pumps. The proposed optimization model provides for describing the modes of the group water intakes operating from the intake external boundary to the tanks. All the limitations of the optimization task can be divided into three non-overlapping groups as follows: balance, technologic, and performance ones. Having calculated the electricity consumption for all significant modes during the year and compared them with the costs at the existing modes without variable speed drives, we can make a reasonable conclusion about the applicability of a variable speed drive in one or more submersible pumps. The proposed model provides for arranging both efficient and technologically allowable operating modes.

Key words

frequency converter , water well , aquifer , submersible pump , hydraulic head , flow distribution task , optimization task , energy input , group water intake

Energy saving in operating deep wells for underground water abstraction

Summary

The share of energy costs in the operating expenditures structure reaches 85%. Taking into consideration the requirements to the reduction of СО2 emissions into the atmosphere as well as the necessity of reducing the costs and water tariffs, energy saving is the priority task for the housing and utility enterprises, industrial, agricultural companies and water and wastewater services providers that are operating deep wells. Different options of installing water lifting equipment in deep wells are considered. The energy efficiency comparison was made on the basis of the software designed by Wilo Company (Germany), pump manufacturer. The specific features of hydraulic calculations of the combined operation of the pump and the well are considered. The data on the structural concepts for deep wells that provide for saving energy spent directly on underground water lifting is set. The economic and financial mechanism of inducing the measures to reduce the energy consumption by water and wastewater services providers on the basis of the conditions of their foreign investment self-sufficiency development is illustrated.

Key words

water intake , ground water , power saving , hydraulic design , submersible pump , well , lift pipes