## Comparison of three methods for the pump energy analysis

Mathematical Modeling, Vol. 4 (2020), Issue 3, pg(s) 82-85

This paper presents a comparison of three methods for any pump energy analysis. Each method is used for the analysis of three different water pumps from the conventional steam thermal power plant – two feed water pumps (FWP1 and FWP2) and condensate pump (CP). For each pump three essential types of mechanical power which defines all energy analysis methods are: delivered power from power producer, real (polytropic) power and ideal (isentropic) power. Method 1 which compares delivered and real (polytropic) power show the best performances, while Method 3 which compare delivered and ideal (isentropic) power should be avoided because it results with too high energy power loss and too low energy efficiency of any pump. Method 2 which compares real (polytropic) and ideal (isentropic) pump power can be used as a good compromise for the pump energy analysis in the most of the cases – its results are similar to results of Method 1.

## ILLUSTRATION OF MODEL CREATION ON EXAMPLE OF APPROXIMATIONS TO THE STEADY STATE CURRENT OF CHEMICAL CYCLIC PROCESSES

Mathematical Modeling, Vol. 1 (2017), Issue 3, pg(s) 159-162

An approach for creation of biophysically based models for the steady state current of cyclic processes is investigated. When the process (like chemical reactions) can be described by a system of linear ordinary differential equations, an analytic expression for its steady state exists. The analytic expression is especially simple for the current of single cycle processes. In biologic context, concentrations of many substances change in a very restricted (patho)physiological range. This allows neglecting some terms of the analytic expression and thus obtaining biophysically based models that are both simple and adequate for description of currents produced by enzymes, pumps or transporters. The approximations obtained could be reduced to the existing empirical models. A clear way of expanding a specific empirical model for obtaining the desired quality and range of validity is also represented. The described approach is general and can be useful for creating biophysically based models of other types of processes.

• ## MULTI-FUNCTION DEVICE OF A CANAL CLEANER FOR PERFORMING A COMPLETE CLEANING OF DRAINAGE CANALS

We offer a multi-functional operating element of rotary type for a channel cleaner, which is capable of performing the entire cycle of cleaning household water reservoirs (ponds), in particular:1. due to the compound rotor:1.1. mow and chop the crop;
2. due to the implementation of detachable body:2.1. mill and transport “dry” soils using a jet of air;2.2. pump water;2.3. extract and transport the soil from under the water;

3. due to the installation of the teeth on the lower movable part of the body:3.1. work as a clamp grapple to remove garbage from water reservoirs (ponds).

The basis of multifunctionality of this invention is in the principle of implementation of the maximum number of hidden abilities of the initial technical system, its rotor, framing, manipulator parts, which implies the subsequent creation of a reclamation robot.

• ## EVOLUTION OF HYDRODYNAMIC CAVITATOR

The original design of a cavitator is a volute (snail) with a tangential inlet connected to the pump and an axial outlet which is attached to the body in the form of a cylindrical tube, which ends with a braking device and a central hole connected to inlet of the pump.
Proposal: 1) to equip cavitator with axial gas extractors in the volute (snail) and at the output from the body, 2) exclude the snail (volute) from the construction and control the interaction of flows by dividing stream leaving the pump into two parts and then merge them in the camera in front of body, 3) organize an axial jet in body with the required structure by using ring nozzles, 4) reduce a vortex component of the current by installing a second straightening snail (scroll) before the body, 5) design the pump as an active generator of elastic vibrations of useful frequencies while maintaining its primary function; – separate it with antivibration bushing.