Pressure sensor and system for regulating a ventilation device

Abstract

A pressure sensor includes: a detection device for ascertaining air pressure and temperature; a computing unit; and a wireless interface. With the aid of the wireless interface, the pressure sensor data which represent a flow state in the surroundings of the pressure sensor are transferred wirelessly to a central control device. With the aid of the central control device, final control elements of a ventilation device are set.

Claims

1. A sensor, comprising: a first detection device that: is positioned at a first region of a building; ascertains data corresponding to an air pressure and a temperature at the first region; includes a computing unit and a wireless interface; and receives, via the wireless interface and from a second detection device that is positioned at a second region of the building that is non-proximal to the first region, data corresponding to an air pressure and a temperature at the second region; wherein: the computing unit determines a flow speed of air within a spatial zone of the building based on the ascertained data corresponding to the air pressure and the temperature at the first region and the received data corresponding to the air pressure and the temperature at the second region; and the sensor causes a modification to a ventilation state within the spatial zone by outputting the determined flow speed via the wireless interface to a control device to which the sensor is communicatively coupled and that responds to the determined flow speed from the sensor by controlling, as a function of the determined flow speed, elements of a ventilation device.

2. The sensor as recited in claim 1, wherein the sensor is configured to detect operating states of the ventilation device.

3. The sensor as recited in claim 1, wherein the output of the determined flow speed is via the wireless interface.

4. The sensor as recited in claim 1, wherein the first detection device is configured to transmit, via the wireless interface and to the second detection device, the data corresponding to the air pressure and the temperature at the first region.

5. The sensor as recited in claim 1, wherein the computing unit is configured to determine the flow speed by executing a self-learning evaluation software.

6. The sensor as recited in claim 1, wherein the first and second regions are in different rooms of the building.

7. A sensor, comprising: a first detection device that: is positioned at a first region of a building; ascertains data corresponding to an air pressure and a temperature at the first region at a point in time; includes a computing unit and a wireless interface; and receives, via the wireless interface and from a second detection device that is positioned at a second region of the building that is non-proximal to the first region, data corresponding to an air pressure and a temperature prevailing at the same point in time at the second region; wherein: the computing unit determines a flow speed of air within a spatial zone of the building based on the ascertained data corresponding to the air pressure and the temperature at the first region and the received data corresponding to the air pressure and the temperature prevailing at the same point in time at the second region; and the sensor causes a modification to a ventilation state within the spatial zone by outputting the determined flow speed via the wireless interface to a control device to which the sensor is communicatively coupled and that responds to the determined flow speed from the sensor by controlling, as a function of the determined flow speed, elements of a ventilation device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic diagram of a flow situation in an indoor space.

(2) FIG. 2 shows a schematic diagram of a first specific embodiment of the system according to the present invention for regulating a ventilation device.

(3) FIG. 3 shows a schematic diagram of a second specific embodiment of the system according to the present invention for regulating a ventilation device.

DETAILED DESCRIPTION OF THE INVENTION

(4) In a schematic cross-sectional view, FIG. 1 shows a diagram of a flow situation in an indoor space of a building. An air flow sweeps along a heated radiator 6 beneath a window sill 10 essentially from bottom to top and along a window 8 essentially from top to bottom. Directions of air flows generated by free convection are indicated by arrows. With the aid of the system according to the present invention, these flows are ascertained in order to regulate a ventilation state or a flow situation within the indoor space from this information.

(5) FIG. 2 shows a top view of a first specific embodiment of the system according to the present invention. System 20 has at least one, preferably multiple, pressure sensors 1 that are situated at a suitable position within several indoor spaces of a building. Each of pressure sensors 1 is equipped with a two-channel detection device 2 for ascertaining air pressure and temperature. Furthermore, pressure sensor 1 includes a computing unit 3, having a preferably high computational power (for example, a high-performance microcontroller) and a wireless interface 4. For the sake of clarity, computing unit 3 and wireless interface 4 are shown on only one single pressure sensor 1. Via wireless interface 4, data ascertained by pressure sensor 1 are transferred to other pressure sensors 1 or to a central control device 5 (for example, to a central device of a building automation system).

(6) Each of pressure sensors 1 is able to ascertain flow situations within the room. For this purpose, the gas law of thermodynamics
pB=nrT

(7) having the parameters:

(8) p . . . pressure

(9) V . . . volume

(10) n . . . amount of substance

(11) r . . . ideal gas law constant

(12) T . . . temperature

(13) is used in order to obtain the evaluation formula for pressure sensor 1 for determining a change in density after a differentiation:
dV/dT=nRd(T/p)/dT

(14) Opening and closing of doors in a laboratory may be considered as a numerical example. The opening or closing of the door causes pressure changes of approximately 3 hPa to 5 hPa in each case, which is about 30 to 50 times greater than the resolution of the pressure sensor 1. Fume hoods may be mentioned as another example for air flow generators, conventional fume hoods causing air flows of several 100 m.sup.3/hr. The air pressure falls along flow lines, is stable in non-ventilated zones, and increases in air blockages.

(15) With the aid of pressure sensors 1, pressure and temperature values are detected in this way at different locations in multiple rooms of the building at the same time. After a calibration phase without flow, these may be used for ascertaining the flow conditions or the flow speeds of the air.

(16) Software is preferably implemented in computing unit 3, which calculates flow speeds from the ascertained temperature and pressure values. For the case that pressure sensor 1, with the aid of known position data, knows the location at which it is placed, one single pressure sensor 1 is able to ascertain the flow speed from the ascertained data. If this is not the case, at least one second pressure sensor 1 is required for ascertaining the flow speed.

(17) Preferably, the above-named software is self-learning, which may mean, for example, that it has adaptive algorithms that detect the flow conditions on a long-term basis and thereby become familiar with them. As a result, the software may even deliver specific information concerning positions of elements of a ventilation device (e.g., window open/closed, flap open/closed, door open/closed) to control device 5.

(18) This makes it possible for the operating characteristics of centralized or decentralized ventilation devices to be adapted to instantaneous flow situations. The above-named ventilation devices may include, for example, final control elements in the form of adjustable flaps 11, adjustable blowers 12 or regulatable fans. The arrows represented in FIG. 2 show directions of air flows within (cross-flows) and outside of the rooms in a diagrammatic manner. An air flow is generally drawn into the building through flaps 11; an air flow is generally discharged from the building through blowers 12.

(19) The ventilation flow adapted with the aid of system 20 according to the present invention makes it possible to advantageously minimize electrical energy consumption for blowers 12 and flaps 11 or increase a room comfort via an adapted air flow. Advantageously, wireless pressure sensors 1, which communicate exclusively with control device 5 by radio, make it possible to avoid wiring complexity. This makes it possible to place integrated, radio-based pressure sensors 1 in a simple way at the most suitable positions for the measurement and simply retrofit them into existing buildings.

(20) Integrated micromechanical pressure sensors are available as known economically priced standard components, the resolution of modern pressure sensors (e.g., of the type Bosch BMP180) allowing a highly accurate detection of pressures. The above-named two-channel sensors also deliver a high-resolution local temperature signal. Both pieces of information are sufficient to determine flow speeds according to the present invention via pressure and temperature differences.

(21) FIG. 3 shows a schematic diagram of a second specific embodiment of the system according to the present invention for regulating a ventilation device. System 20 is situated in an industrial clean room having a clean room cell 7. Multiple air nozzles 13 are recognizable above clean room cell 7, the air nozzles being supplied with a filtered air flow via a filtration and heating device 14 and/or a climate control device 15. An essentially laminar air flow extends downwardly from air nozzles 13, the main purpose of the laminar air flow being to remove dust particles from clean room cell 7, i.e., conveying them to the outside with the aid of suction systems (not shown) on the bottom of clean room cell 7.

(22) According to the present invention, it is provided that multiple wireless pressure sensors 1 are attached at various positions for detecting flow speeds. Pressure sensors 1 may, for example, also be attached to persons within clean room cell 7. Furthermore, pressure sensor 1 may be situated at various additional positions (for example, industrial equipment) within clean room cell 7. The flow speed of the laminar air flow adapted with the aid of the detected flows thus makes it possible to eliminate an interfering turbulence and accordingly a potential source of dust. The basic mode of operation with the aid of wireless interface 4 is the same as has been already explained above with reference to FIG. 2.

(23) As a result, air flows within clean room cell 7 are thus advantageously regulated by filtration and heating device 14 activated by control device 5 and/or climate control device 15. The regulated air flow makes it possible in this way to regulate air purity, i.e., an important parameter for industrial clean rooms.

(24) In summary, using the present invention, a pressure sensor, a system and a method are provided, which allow an adaptive regulation of a ventilation state within a room in a simple and convenient manner. With the aid of networked, decentrally positioned intelligent pressure sensors, which are able to detect flow states in the surroundings of the pressure sensors, data representing a flow state in the surroundings of the pressure sensors are transmitted via a wireless interface to a central control device.

(25) Consequently, final control elements of a ventilation device are activated with the aid of the control device and a flow situation is adapted as a result. The system according to the present invention is scalable, with the result that tasks may be carried out on a higher level of abstraction using data which have been ascertained on a lower level of abstraction.

(26) The intended flow situation is advantageously predefined in such a way that power consumption of the ventilation device is minimized, operating characteristics of elements of the ventilation device are time-controlled, an air flow is set in a pre-defined manner (for example, minimized), etc.

(27) Advantageously, a conventional pressure sensor may be simply and cost-effectively retrofitted to become a radio-based pressure sensor according to the present invention with the aid of a computing unit and a wireless interface.

(28) Although the present invention has been described with reference to preferred exemplary embodiments, it is not limited thereto. In particular, the above-named examples of rooms and ventilation devices are merely exemplary. It is of course also conceivable to use the present invention for any situations in which gaseous fluids are to be moved in spaces in a defined manner.

(29) Those skilled in the art will therefore modify or combine the described features of the present invention in a suitable way, without departing from the essence of the invention.