FI112532B - Unit for measuring and adjusting air flow - Google Patents

Description

112532

The present invention relates to an airflow control and measurement unit for supply air to a room, which unit consists of a ruptured tubular jacket connected to the supply air duct. Many different control device structures are known in the art. Some also include the ability to measure airflow. The problem with all known devices is either poor air flow control or an unreliable air flow measurement method. Poor air flow control is often due to the fact that the free area 10 cannot be changed in a mathematically credible manner. When the back pressure of the opening decreases to almost nonexistent, we move on to "I feel the area". Because the velocity of the airflow is rarely uniform throughout the free surface area of the duct, the dynamic pressure measurement method used by several regulators can be considered unreliable.

15 Since approximately 20-25% of the energy consumption of office and other public buildings is due to air conditioning, it is important that the air flow is controlled so that the right amount of air is achieved in the desired space. This, of course, requires that the accuracy of the available air flow control and measurement devices is good. Good means that the measurement accuracy should be +/- 5%.

. 20 The most common air flow measuring devices on the market are the so-called air flow meters. single-point, measuring devices, that is, they measure the dynamic pressure from a single point in the duct.

In this case, the accuracy of the measurement is in the order of +/- 15-30%, ie the emissions of the air currents are considerable. This, of course, leads to overconditioning of some premises and to the opposite; too little. When rooms are sufficiently ventilated, this usually leads to complaints. Doing so will raise the airflow of the entire building in ignorance, so that complaints will stop. Correspondingly, this leads to a situation where the energy consumption of the building is increased, and there is no "reasonable" explanation for it.

Supply air devices and air flow measurement and control units known per se are disclosed in, for example, FI patents 71614 and 81666 and in patent application 20000681.

It is an object of the present invention to provide a new type of, relatively simple, reliable, easy to adjust and, in addition, relatively silent air flow measuring and regulating unit. The unit according to the invention is characterized in that an axially movable adjusting plate 2 112532 is provided inside the tube casing. The adjusting plate is movable stepwise between the rows of holes in the tube casing.

By adding up the open rows of holes and adding to it the number of nozzles in the baffle plate, by measuring the static pressure, the amount of air flow through the device 5 can be reduced to an accuracy of +/- 5%.

Airflow qv 1 / s = kl x nl + k2 x n2 where kl is the coefficient of the baffle nozzles (determined by the control pressure) nl is the number of open nozzles 10 k2 and n2 are respectively the coefficient and the number of holes in the pipe.

Various embodiments of the invention are set forth in the dependent claims.

The invention will now be described, by way of example, with reference to the accompanying drawing, in which Figure 1 shows a unit for measuring and controlling the airflow in section, and Figure 2 shows an adjusting plate in axonometric view.

* 't; The air flow control and measurement unit 1 for supply air to the room compartment forms'. the housing 10 connected to the supply air duct 2 within which is located the actual weather; working and measuring unit. The unit consists of a routed tube jacket 3 within which. 20 is an axially movable adjusting plate 5 with nozzles 4. are formed in the control plate 5 through the holes, the edges of which are bent outwardly in the direction of the air flow control plate 25 5 is attached to the static pressure measuring point 8, by means of which a pressure difference is measurable Y like from the pipe sleeve 3 inside / outside of the control plate 5 nozzles can be,.. If necessary, plug in, for example, rubber plugs to reduce the adjustment range.

• I

Claims (7)

An air flow control and measurement unit (1) for supply air to a room, which unit consists of a torn tube (3) connected to the supply air tube (2), characterized in that an axially movable control plate (5) is provided inside the tube. 5). Adjusting and measuring unit according to claim 1, characterized in that the adjusting plate (5) is movable stepwise between the rows of holes in the tube casing. Adjustment and measurement unit according to claim 1 or 2, characterized in that the adjustment of the adjustment plate is carried out by means of an axis (6) attached to the adjustment plate, which has adjustment lugs (7) for longitudinal adjustment. 3, 112532 Adjustment and measurement unit according to one of the preceding claims, characterized in that the nozzles (4) consist of holes in the adjusting plate (5), the edges of which are bent outwards in the direction of the air flow. 5. An adjusting of the preceding claims and according to the measurement unit 15 characterized in that the control disc (5) is secured to the static pressure measuring point (8), by means of which the differential pressure is measured between the pipe sleeve (3) inside / outside. Adjustment and measurement unit according to one of Claims 1 to 4, characterized in that the shaft (6) is hollow and acts as a measuring unit. Adjustment and measurement unit according to one of the preceding claims, characterized in that the nozzles (4) in the adjusting plate (5) can be plugged into the adjustment area. to reduce. I * »4 112532