Method and equipment for cooling generators

Installation for cooling cooling water-conducting copper pipes present in large electric generators cooled with hydrogen gas, by means of which installation a minimum quantity of CO2-free air can be pumped into the cooling circuit in a targeted manner depending on the oxygen content of the cooling water in the case of a high oxygen content or pure nitrogen N2 in the case of a low oxygen content, and whereby the critical air quantity ratio for the hydrogen H2 contained in the cooling circuit can be kept outside the range of 4-75% H2 in the air contained in the cooling water and thus outside the dangerous quantity ratio, with a connection to a stator cooling water system, wherein the system comprises a stator cooling water tank (2) with outgoing pipe (3) and riser tube (13), and wherein the outgoing pipe (3) leads the cooling water through pumps (4), heat exchangers (6), a filter (7) and thereafter optionally through an ion exchanger (9) back into the stator cooling water tank (2) or into the cooling channels of a stator winding in a generator (1), and wherein the installation includes an air injection system (60) with a control system with measuring instruments for the continuous measurement of CO2 in the incoming supply air and H2 in the outgoing exhaust air, and a control unit (65) with operating elements, wherein limit values can be entered for the CO2 concentration and also for the H2 concentration, above which an alarm can be output or measures can be initiated automatically,

• wherein the air injection system (60) is equipped with a plant-side valve (V11) via which oil- and dust-free air can be passed through the pipe (66) and then through a pressure sensor (PS1) and a flow meter (FS1), then through a CO2 and H2O separation column (61) then via a second pressure sensor (PS2) into a CO2 analyzer (62) and via a plant-side valve (V12) via a pipe (64) into the stator cooling water tank (2), and wherein from the riser tube (13) gas can be drawn off via a plant-side valve (V13) by means of a pump (PM) with a pump impeller (63), which can be fed via an H2 analyzer and a valve (14) into the pipe (66) and via the valve (V12) back via the pipe (64) into the stator cooling tank (2), and in that the control unit (65) is an electronic control unit (65) with an input field and display, which belongs to the plant as a control box and by means of which the measurement data of all connected sensors and analyzers of the system can be evaluated, at least the CO2 content of the injected air and the H2 content in the riser tube (13) can be measured, and by means of which an acoustic and optical alarm can be emitted when an adjustable limit value is exceeded.