Abstract: A system in one embodiment includes a heat exchanger, a detection unit, and a controller. The heat exchanger includes a first passage and a second passage configured for exchange of heat therebetween. The first passage is configured to receive a boil-off gas stream of a first cryogenic fluid. The second passage is configured to receive a liquid stream of a second cryogenic fluid. The detection unit is configured to detect a characteristic of the boil-off gas stream. The controller is configured to, responsive to information acquired from the detection unit corresponding to the characteristic, control the flow of the second cryogenic fluid to provide sufficient exchange of heat from the boil-off gas stream via the heat exchanger to condense at least a portion of the boil-off gas stream. A liquid stream of the first cryogenic fluid is output from the first passage and returned to a first tank.