摘要 |
A fluid flow control system has a heating device for heating a fluid and a first flow path for providing the heated fluid from the heating device to a use region. A heat exchanger has a supply path which is adapted to receive fluid from a fluid supply. The heat exchanger also has a outlet path adapted to receive fluid from the use region, whereby the fluid in the supply path is pre-heated by the fluid in the outlet path. A second flow path provides pre-heated fluid from the supply path of the heat exchanger to the heating device. A first flow modulating device controls fluid flow through the outlet path. A second flow modulating device controls the flow of pre-heated fluid along the supply path. A flow control device controls each of the first and second flow modulating devices such that, during use, the fluid flow rates in the fluid supply path and outlet path of the heat exchanger are balanced, so as to be substantially the same. |