METHOD FOR SPACECRAFT TEMPERATURE CONTROL HYDRAULIC SYSTEM FILLING WITH COOLANT Russian patent published in 2009 - IPC B64G1/50 B67D5/00 

FIELD: engines and pumps; cosmonautics.

SUBSTANCE: invention is related to methods for ground filling of low temperature hydraulic circuits of spacecraft temperature control systems that operate during flight at low negative temperatures. It may also be used for equipment and units operated under conditions of Extreme North. Method for filling of hydraulic system equipped with hydropneumatic compensator of working medium volume expansion, according to invention, includes its vacuumising and filling with deaerated coolant. Then excessive coolant is drained, and free air remained are dissolved in filled system by means of its pressurising by maximum permissible pressure. Coolant circulation is created in system, average coolant temperature is measured, as well as volume of compensator gas cavity. Afterwards coolant is drained completely, and working pressure is established in system. Method peculiarity consists in the fact that prior to vacuumising of system dew point temperature t₁ of filling gas is measured. Then system is blown by gas of the same name with dew point temperature t₂ < t₁ for the time sufficient for complete replacement of gas in system, and dew point temperature t₃ of gas is again measured at the outlet from system. If condition t₃ < t₁ is fulfilled, conclusion is made on absence of liquid phase in internal cavities of system, and its vacuumizing is started. If this condition is not fulfilled, system blowing is continued until measured temperature does not satisfy this condition, and then system vacuumising is started. Method may be realised on existing filling equipment by servicing personnel of ordinary qualification. Analysers of gas humidity used in this method are serially produced.

EFFECT: increased quality of hydraulic systems filling with coolants by means of control of internal cavities of systems for absence of liquid phase in them or its highly saturated vapors.