| 摘要 |
A local heating system according to the present invention includes a boiler producing hot water for heating; a water supply pipe for supplying the hot water; a hot water pipe buried in a room; a return water pipe for returning the hot water to the boiler; a circulation pump for forcibly flowing the hot water; a bypass pipe installed between the water supply pipe and the return water pipe; a three-way valve including a discharge unit connected to the boiler, a first intake unit connected to the hot water pipe, and a second intake unit connected to the bypass pipe; a three-way valve driving actuator which controls the extent of opening the three-way valve and varies an inner flow passage of the three-way valve; a return water flowmeter for detecting a return water amount (Qr) of the hot water via the return water pipe; a bypass flowmeter for detecting a bypass amount of the hot water via the bypass pipe; and a controller controlling the circulation pump and the three-way valve driving actuator. The controller maintains the total amount of the hot water returned to the boiler equal to or greater than an operation minimum amount (Qm) of the hot water returned to the boiler via the hot water pipe by bypassing the hot water to the boiler via the bypass pipe when the return water amount (Qr) is less than the operation minimum amount (Qm). [Reference numerals] (AA) Start; (S10) Opening an automatic control valve; (S11) Preset temperature > Indoor temperature; (S12) Closing the automatic control valve; (S13) (Water supply temperature - Return water temperature) >=ΔTw; (S14) Maximum extent of opening the automatic control valve; (S16) Maintaining Qr over Qm by bypassing hot water; (S17) Deceleration-driving a circulation pump; (S18) Return water temperature is increased over Td1 within a reference time(td)?; (S19) Maintaining Qr over Qm by controlling a bypass amount while reducing the extent of opening the automatic control valve as much as the controlled reference opening extent within a range over the middle opening extent; (S20) (Preset temperature - Indoor temperature) >=ΔTr1; (S21) Extent of opening the automatic control valve is less than the middle opening extent?; (S22) Maintaining Qr over Qm by reducing the extent of opening the automatic control valve to the middle opening extent and controlling the bypass amount; (S23) (Preset temperature - Indoor temperature) >=ΔTr2; (S24) Return water temperature is decreased?; (S25) Maintaining Qr over Qm by increasing the extent of opening the automatic control valve as much as the reference opening extent control amount and controlling the bypass amount; (S26) Return water temperature is increased over Td2 within a reference time(td)?; (S27) Maintaining Qr over Qm by controlling the bypass amount while reducing the extent of opening the automatic control valve as much as the controlled reference opening extent within a range over the minimum opening extent; (S28) Indoor temperature is increased in a continuous operation for a maximum heating time(Tm)? |
