Multielement thermal-emission power-generating assembly for loop reactor tests

Abstract

Loop reactor tests of power-generating assemblies, most often called power-generating channels (PC, C), are a very important step in the refinement of one of the complicated units of a thermal-emission reactor-converter and a nuclear power plant as a whole [l].The exploratory stages of loop tests are intended for further improvement of the construction of the PGC for the purpose of increasing the output power and service-life characteristics, decrease the size, and so on. The tests should check the possibility and efficiency of using new materials, new arrangements and construction-technological solutions with respect to the main units and the PGC as a whole. Such a refinement requires a large volume of tests. Considering the high cost of developing and performing reactor tests of a PGC, it is necessary to refine in loop tests several technical solutions at the same time, for example, for the gas-removing units of power-generating elements. However, in a multielement PCK2 with serially connected power-generating elements the energy-characteristics of only the entire PGC without separating the energy characteristics of an individual element can be measured, which substantially decreases the amount of information obtained. As a result, in the course of the tests an integral of the technical solutions is refined, though at a given stage, in the absence of a specifically developed object and a limited volume of tests, it is desirable to refine and perform comparative investigations of several technical solutions with respect to all of the most important units of the power-generating elements and the channel in the same tests. Such a PGC should be equipped with instrumentation in a manner so as to be able to measure during the tests the voltage or even the current-voltage characteristic of each element and thereby to monitor the working capacity of each modification with different technical solutions in the course of the tests and not after investigations in hot chambers.We have proposed [2] an experimental-research PC~ that makes it possible to measure the voltage and therefore the generated power of each element. In contrast to the standard PGC with a five-layer collector packet, in the experimental-research PGC the guard electrode between two layers of the collector insulation is not continuous but rather made in the form of metal strips which are insulated from one another, each strip being electrically closed with the aid of a switching unit on the end of the multielement bridge of one of the power-generating elements. Each strip is equipped with a terminal for connecting to a potentiometric probe.Each element in such a PGC can possess different technical solutions, for example, it could be prepared from different materials (emitter, collector), its length could be different, the schemes for removing gas could be different, and so on. It is possible to fabricate a PGC from groups of identical components, where identical technical solutions are used in a group of two, three, and so on components and different solu...