The Stability of Water Ejector Using in Heating System

In the heating system, the water ejector can use the "surplus pressure" to pump return water from return pipe instead of using mixing pumps, thus achieving the purpose of energy conservation. The water ejector is normally devised in the design condition, however, it usually does not operate at the design point because the pressure and flow rate of water in water ejector varies with the fluctuation of adjacent heat consumer, which causes the deviation of the indoor air temperature from the designed value. In the present study, the allowed pressure fluctuation of water ejector was investigated under the condition that the indoor air temperature was maintained in a certain range. The experimental results showed that when indoor air temperature was set at°C, the allowed pressure fluctuation range for the water ejector in Harbin was -10%∼20%, and it expanded as the outdoor design temperature increased and/or the supply water temperature of primary network reduced.