METHODS AND SYSTEMS FOR ENERGY EXCHANGE

Methods and systems for energy recovery in desalination or other systems are provided to transfer the pressure energy from one fluid to anther fluid. A system for energy recovery with a container comprises two sections separated by one or plurality of flexible impermeable diaphragms and pressures of the two fluids in the two sections are transmitted during the cyclical filling and pumping operations, as well as flow control valves. As one embodiment, two flexible impermeable tubes operable to receive two fluids of different pressures respectively connect to flow control valves. The first fluid and the second fluid are separated by the flexible impermeable diaphragm formed by the flexible tubes. Cyclical inflows of the two fluids transmit the higher pressure of one fluid to the other through the diaphragm and transfer the energy from one fluid to the other.