Y. Dobriansky*, M. Duda and D. Chludzinski

University of Warmia and Mazury in Olsztyn, Faculty of Technical Sciences,
ul. Oczapowskiego 11, 10-736 Olsztyn, Poland

Corresponding Author, dobr@uwm. edu. pl

Abstract

The purpose of the work is to develop a self-acting circulating pump which transfers heat downward and acts with help of local heat that has to be transferred. The pressure difference of the saturated vapour is used for moving warm liquid downwards. The principles of action and the possibility of developing such a device by using laboratory experimental methods are presented. The device operates cyclically, is self-controlled, has simple design, and has no mechanical moving elements except flaps of check valves. This pump can be used with solar installation instead of electrical circulating pump.

Keywords: passive heat transfer downwards, self-acting, circulation, pump, liquid, reverse thermosiphon.

1. Introduction

Devices which use the phenomenon of natural convection, transfer heat upward, act autonomously and are often used in practice. There has been great interest in the invention of a device of passive heat transfer downward and there have been some technical proposals [1], [5], [6], [7]. However, they are not used in practice due to certain shortcomings: complicated mechanical design, high cost or dangerous materials, short distance of heat transfer etc. Only one engineering solution is used in practice widely. This system is a mechanical liquid pump that is being powered by using external energy sources. The main drawback of this system is that it does not act autonomously.

Solar collectors as a rule are located above a tank-accumulator of warm water in solar installations. Electrical circulating pumps are used for moving warm heat-carrier downwards from collectors to a tank. The cost of an electrical circulation pump with appropriate control device amounts about 20% from total cost of solar installations for a family house. Usual solar installation depends on power supplies. Moreover, these elements fail the most often in comparison with other parts of a solar installation.