The control apparatus and method of fresh-air flow rate using pressure difference of terminal unit in air and water central AHU system

摘要

An outer air induction control device of a water-air central air conditioning system and a method thereof are provided to induce a pressure decrease in a terminal unit by mounting a taper nozzle at an outlet of a blower in the terminal unit and accelerating indoor circulated air and to control induction rate of the terminal unit in proportion by using a pressure difference with a mixed air chamber for introducing fresh air. An outer air induction control device of a water-air central air conditioning system comprises an outer air induction terminal unit(2) installed at one side of the lower side of each floor slab in a building to induce a pressure decrease of indoor circulated air and to introduce fresh outer air due to the pressure decrease; an indoor supply duct(4) connecting the outlet port of the outer air induction terminal unit with each air conditioning zone(100) to circulate indoor air; a cold/hot water supplying unit(6) supplying cold/hot water to exchange heat with indoor circulated air flowed toward the outer air induction terminal unit; and a fresh outer air induction controlling unit(8) detecting difference between inner and outer pressure of the outer air induction terminal unit and performing proportional control to approach to a designed value by a PID(Proportional Integral and Derivative) control logic.