RU-2861513-C1 - DEVICE FOR CATHODIC PROTECTION OF OBJECTS

RU2861513C1RU 2861513 C1RU2861513 C1RU 2861513C1RU-2861513-C1

Abstract

FIELD: electrochemistry. SUBSTANCE: invention relates to a device for cathodic protection of objects. The device comprises a thermoelectric generator, in the housing of which thermoelements are placed on the inner wall, the hot side of which is a heat receiver from the combustion of a gas burner, as well as an air intake, a pipe for an exhaust pipe, a gas supply tube with a valve for connecting it, and a gas igniter. Wherein the device further comprises a turbexpander connected to the gas supply tube, on the axis of which an electric generator is placed, and an external closed casing-shell of the housing on all sides, the inner walls of which have gaps with the outer walls of the cooled housing. The outlet of the turbexpander of cooled low-pressure gas is connected to the upper part of the casing-shell, while the gas burner is connected to its lower part through an opening in the housing, and the outputs of the electric generator and the thermoelements are connected to a current summer of the device, the output of which is connected to the cathodic protection object. EFFECT: expanding the arsenal of technical means that allow optimal temperature conditions for the thermoelements of a thermoelectric generator for their long-term stable operation. 1 cl, 1 dwg

Inventors

SHCHeklein Sergej Evgenevich
Popov Aleksandr Ilich
Sergeev Dmitrij Aleksandrovich
ZHUKOV ALEKSEJ VLADIMIROVICH

Dates

Publication Date: 20260505
Application Date: 20250523

Claims (1)

A device for cathodic protection of objects, containing a thermoelectric generator, in the housing of which on the inner wall there are thermoelements, the hot side of which is a heat receiver from the combustion of a gas burner, and an air intake, a branch pipe for an exhaust pipe, a gas supply pipe with a valve for its connection and a gas ignition device, characterized in that it additionally contains a turboexpander connected to the gas supply pipe, on the axis of which an electric generator is placed, and an outer casing-shell of the housing, closed on all sides, the inner walls of which have gaps with the outer walls of the cooled housing, wherein the outlet of the turboexpander of cooled low-pressure gas is connected to the upper part of the casing-shell, while a gas burner is connected to its lower part through an opening in the housing, and the outputs of the electric generator and thermoelements are connected to a current adder of the device, the output of which is connected to the object of cathodic protection.

Description

The invention relates to energy facilities, in particular, to the cathodic protection of gas and oil pipelines, to the cathodic protection of tanks and other metal structures subject to corrosion due to the presence of stray electric currents in the ground. Autonomous current sources based on thermoelectric generators (TEG), such as GTG-150, Global TEG 5220MPS, AITT-500g, are used as alternative current sources for cathodic protection of objects in the absence of overhead power lines. However, they have a number of common disadvantages that limit their use in industry. Numerous thermoelectric generators of similar application are known, for example, “Universal thermoenergetic generator (variants)” by the authors Popov A.I. and Shchekleyin S.E. under the patent of the Russian Federation No. 2650439, IPC H01L 35/28. This device contains a battery of thermoelectric modules, hot electrodes connected to a heat source, and cold electrodes connected, for example, to a water tank via a steam pipe or a ring thermosiphon. These devices are highly efficient. Another disadvantage of this technical solution is the lack of adjustment of the parameters of both the hot and cold electrodes of the TEG to ensure an optimal temperature difference between them, so that the required operating mode of the thermoelements is maintained. The “Cathodic Protection System for a Main Gas Pipeline” by D.L. Zhukovitsky and A.A. Tsynaeva is known under Russian Federation Patent No. 2333352, IPC C23F 13/02; H01L 35/30. The system comprises a gas distribution station on the main gas pipeline, a compressed natural gas supply line, and a temperature differential source—a vortex tube—that enables the TEG to operate by creating a cavity for hot and cold gas flows. This system thus simultaneously regulates both the cold and hot gas flows, which respectively reach the cold and hot electrodes of the TEG's thermocouples. The disadvantage of this system is the high gas consumption required to ensure the nominal operating mode of the vortex tubes and also their inability to provide a temperature difference of up to 400...450 degrees Celsius to achieve maximum efficiency of thermoelectric generators. Vortex tubes can be used for such applications only if a gas distribution station is available, receiving the mixed return natural gas from the receiver. However, most stand-alone cathodic protection devices are located remotely in hard-to-reach areas, operate without a gas distribution station, and the gas in such devices would have to be vented into the atmosphere. Furthermore, this system cannot be used at most facilities that already utilize the method of burning small amounts of natural gas from their main gas pipeline to power the TEG. Specifically, the operation of the GTG-150N generator, according to the ZhTSISh documentation 305642.056, which is part of the IT-150 current source, widely used by Gazprom enterprises, requires a gas flow rate from the gas pipeline of 650 g/hour (see Fig. 1, Appendix 1, four pages of this application), which is insufficient for the operation of the vortex tube. The GTG-15N generator is designated by pos. 6 in Fig. 1. The problems of using TEG are described in more detail in the materials of the Scientific and Technical Conference of Young Managers and Specialists, presented in the report "Improving the operational reliability of autonomous sources used in Gazprom Transgaz Ekaterinburg LLC" (see Appendix 2, selectively on the topic of TEG pages 1, 2, 3, 4, 8, 9, 11, 15, 16, 17, 18). On page 16 is shown the external appearance of the GTG-150, Fig. 4.5, which is part of the IT-150 current source. At the request of the Nevyansk LPU MG, staff from the Ural Federal University Department of Nuclear Power Plants and Renewable Energy Sources voluntarily investigated the failure of GTG-150 thermocouples on one of the IT-150 units submitted for study. It was determined that optimal operation was not being ensured. Specifically, the hot electrodes of the thermocouples were overheating due to the combustion gas, while their cold electrodes were insufficiently cooled by the outside air. Insufficient cooling, especially in summer, does not provide the required temperature differential across the thermocouple electrodes, which also reduces their efficiency. The thermoelectric generator GTG-150, Fig. 4.5, p. 16 (Appendix 2), was chosen as the closest technical solution (prototype), as the most widespread one used at Gazprom enterprises and in other organizations of the country. The disadvantage of this technical solution is the failure of the generator when its thermal elements on the hot side overheat due to unstable cooling of the cold side by atmospheric air. The technical problem addressed by this invention is increasing the reliability of TEGs and enhancing the efficiency of their thermocouples. The solution to this technical problem is linked to expanding the range of technical means to ensure optimal temperature conditions for