Electronic device and method for control of a building management system

Abstract

Electronic device for regulating a thermo-fluidic system for a building, including a heating/cooling system including mixing valves adapted to control flows of hot/cold water within said heating/cooling system, the device including a control unit adapted to: receive a main signal from a building management system; receive a predefined reference signal representative of a desired parameter for the building; receive environmental signals from environmental sensors placed in the building and adapted to measure environmental parameters of said building; issue a control signal towards an actuator associated with a respective mixing valve in order to modify the opening or closing thereof.

Claims

1. An electronic device for regulating a thermo-fluidic installation for a building, comprising a heating/cooling system including mixing valves or gates adapted to control flows of hot and/or cold water within said heating/cooling system, said device comprising a control unit adapted to: receive a main signal from a building management system; receive a predefined reference signal representative of a desired parameter for the building; receive environmental signals from environmental sensors placed in the building and adapted to measure environmental parameters of said building; issue a control signal towards an actuator associated with a respective mixing valve or gate in order to modify opening or closing thereof, wherein: said electronic device is adapted to be installed between a cable that carries said main signal and said actuator associated with said respective mixing valve or gate, said control unit further comprises: a sum block adapted to compute an error (e(t)) between a reference temperature and an internal temperature (T.sub.interna) measured inside said building; a derivative block adapted to derive an error first derivative (de(t)/dt) of said error signal (e(t)); and a fuzzy controller block adapted to apply a fuzzy algorithm in order to compare said main signal with said error (e(t)) and said error first derivative (de(t)/dt) signals, so as to obtain said control signal directed towards said respective mixing valve or gate.

2. The device according to claim 1, wherein the thermo-fluidic system for a building further comprises an air treatment unit including gates allowing the entry of air from outside the building or recirculation air from said building into the air treatment unit, said device being also adapted to send a control signal to an actuator associated with a respective gate in order to control the opening or closing thereof.

3. The device according to claim 1, wherein the control signals propose modifications of the main signal for obtaining a predetermined percentage of opening or closing of said mixing valves or said gates.

4. A method for regulating, by an electronic device, a temperature of a thermo-fluidic installation for a building comprising a heating/cooling system having mixing valves adapted to control flows of hot and/or cold water within said heating/cooling system, said electronic device comprising a control unit adapted to: receive a main signal from a building management system; receive a predefined reference signal representative of a desired parameter for said building; receive environmental signals from environmental sensors placed in said building and adapted to measure environmental parameters of said building; issue a control signal towards an actuator associated with a respective mixing valve in order to modify opening or closing thereof, said method comprising the steps of: connecting said electronic device with a cable that carries the main signal and a respective actuator associated with one of said mixing valves; receiving a reference temperature signal (T.sub.rif); computing an error (e(t)) between the reference temperature and an internal temperature (T.sub.interna) measured inside the building; computing a first derivative of the error (de(t)/dt); applying a fuzzy algorithm in order to compare the main signal with the error (e(t)) and error first derivative (de(t)/dt) signals, so as to obtain the control signal directed towards said mixing valve.

5. A method for regulating, by an electronic device, a carbon dioxide level of a thermo-fluidic installation for a building comprising a heating/cooling system including gates adapted to control flows of hot and/or cold water within said heating/cooling system, said electronic device comprising a control unit adapted to: receive a main signal from a building management system; receive a predefined reference signal representative of a desired parameter for said building; receive environmental signals from environmental sensors placed in said building and adapted to measure environmental parameters of said building; issue a control signal towards an actuator associated with a respective gate in order to modify opening or closing thereof, said method comprising the steps of: connecting said electronic device with a cable that carries the main signal and a respective actuator associated with one of said gates; receiving a reference carbon dioxide level signal (C.sub.rif); computing an error (e(t)) between the reference carbon dioxide level and an internal carbon dioxide level (C.sub.interno) measured inside the building; computing a first derivative of the error (de(t)/dt); applying a fuzzy algorithm in order to compare the main signal with the error (e(t)) and error first derivative (de(t)/dt) signals, so as to obtain the control signal directed towards said gate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and advantages of the invention will become apparent from the following detailed description, given merely by way of non-limiting example with reference to the annexed drawings, wherein:

(2) FIG. 1 shows a block diagram of the electronic device according to the present invention;

(3) FIG. 2 shows a diagram of a building wherein climatic conditions are controlled by means of an open-loop system;

(4) FIG. 3 shows a diagram of an air treatment unit; and

(5) FIG. 4 show a block diagram of the method for regulating the temperature/carbon dioxide level carried out by the device of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) FIG. 1 shows a device for controlling the climatic conditions of a building according to the present invention.

(7) The device 1 is adapted to be associated with a traditional heating/cooling system of a building (of the type including a heating or cooling unit that sends hot or cold water towards a distribution system of a building by opening/closing a mixing valve), or more in general with an HVAC (Heating, Ventilation and Air Conditioning) system also comprising, as aforementioned, an air treatment unit.

(8) FIG. 2 shows a traditional heating system comprising a heating unit 50 (or, as an alternative, a cooling unit), a mixing valve 52 and a heating device 54 (or, as an alternative, a cooling device) of a building 56. Hot (or cold) water is delivered by the unit 50 towards the building 56 in the direction shown by the arrow A by opening/closing the mixing valve 52.

(9) FIG. 3 shows an ATU 80 including a heating battery 82, a cooling battery 84 and a post-heating battery 85.

(10) A first duct 86 allows external air to enter and flow, through a first gate 88, towards the ATU 80, while a second duct 90 ensures recirculation of air coming from a building (not shown in the drawing) towards the ATU 80, through a second gate 92.

(11) Mixing valves 52′, similar to the mixing valve 52, are associated with the heating battery 82, the cooling battery 84 and the post-heating battery 85, which valves are adapted to control the hot/cold water flows within the ATU 80 in order to heat/cool outside air or recirculated air.

(12) The treated air then flows out of the ATU 80 and is sent, through a third duct 94, towards the building to control.

(13) Referring back to FIG. 1, the device 1 comprises a control unit 2, e.g., a microprocessor, which is adapted to receive: a main signal 4 coming from a per se known building management system (BMS); a reference signal 6, preferably a temperature signal, set by a user and representative of a desired parameter for the building involved; environmental signals 8, coming from environmental sensors located in the building (not shown in the drawing), which are adapted to measure environmental parameters such as temperature, humidity, carbon dioxide level, etc.

(14) The building management system is an existing system associated with the controlled building and adapted to supply control signals to the mixing valves 52, 52′ and/or to the gates 88, 92 for opening/closing the air ducts 86, 90 of the ATU 80.

(15) The control unit 2 is adapted to issue a control signal 10 towards an actuator of a respective mixing valve 52, 52′ or gate 88, 92. In particular, such control signals 10 are sent to respective actuators of the valves 52, 52′ and of the gates 88, 92, which respectively open/close the valves 52, 52′ and the gates 88, 92.

(16) The control unit 2 is powered in a per se known manner, e.g., via a 24V or 220V power signal.

(17) In order to obtain the control signal 10, the control unit 2 carries out a temperature regulation process and/or a carbon dioxide level regulation process, respectively, which will be described more in detail below.

(18) The device 1 according to the present invention is an electronic device capable of creating a closed-loop system in a heating/cooling system of a building by integrating the information coming from the environmental sensors.

(19) The actuators that receive a respective control signal 10 are adapted to change the percentage of opening of a three-way mixing valve 52, 52′ or the percentage of opening of a gate 88, 92.

(20) The device 1 is installed upstream of each actuator, between the cable that carries the main signal 4 and the actuator itself.

(21) In a preferred embodiment of the invention, the control signal 10 proposes a modification to the main signal 4 to be applied to the actuator.

(22) Through the control actuators, one can regulate the opening/closing of the gates 88, 92 of the air treatment unit 80 and the flow rate of hot/cold water coming from the heating/cooling units in order to attain the desired comfort.

(23) The control device 1 according to the present invention allows reducing the costs for integration into existing systems.

(24) It operates according to the IoT (Internet of things) logics; it can read analog signals and, through an elaboration, create new ones.

(25) FIG. 4 shows a block diagram of the temperature regulation method performed by the control unit 2 for regulating the temperature in the building.

(26) This method is preferably based on fuzzy, fuzzy PID like or possibly fuzzy PID algorithms.

(27) The fuzzy logic is used because it allows regulating a system via formalization of concepts derived from common experience. These types of regulation algorithms offer very good performance and do not require mathematical modellization of the system being controlled, nor they require that an estimation of PID regulation parameters which are not always intuitive.

(28) The idea at the basis of these algorithms is that a quantity can also take, in addition to Boolean values, a set of values which indicate the degree of truthfulness of a given expression.

(29) The temperature regulation method according to the present invention employs, in order to regulate the building's internal temperature, an algorithm whereby a control signal 10 is obtained which, by opening or closing the valve 52, 52′ or a gate 88, 92 of the air treatment unit 80, allow to get the desired temperature (or carbon dioxide level) inside the building.

(30) In FIG. 4, a reference value, e.g., a reference temperature Trif, is defined by the user and sent to the control unit 2 via the temperature signal 6. A sum block 100 in the control unit 2 computes the error e(t) between the reference temperature Trif and an internal temperature of the building Tinterna measured by a temperature sensor installed inside the building and sent to the control unit 2 via one of the environmental signals 8.

(31) The error e(t) and its first derivative de(t)/dt are sent to a fuzzy controller block 102 of the control unit 2, which, through a per se known fuzzy algorithm, compares the main signal 4 with the error signals e(t) and de(t)/dt and in turn produces the control signal 10 directed towards a valve 52, 52′.

(32) Preferably, the device 1 sends a 0V to 10V signal to the actuator of the valve 52, 52′ to open/close.

(33) As far as the carbon dioxide level regulation is concerned, the control signal 10 is computed by following a scheme similar to that of FIG. 4 on the basis of a reference carbon dioxide level value Crif and a measured carbon dioxide level value Cinterno, and is sent to the opening/closing gate 88, 92 of the air treatment unit 80 of the HVAC system.

(34) Two input variables are used by the above-described control algorithm for both the temperature regulation and the carbon dioxide regulation, i.e., the regulation error e(t) and its derivative de(t)/dt.

(35) In the methods according to the present invention, the error e(t) and its variation Δe(t) are used as an antecedent. The fuzzy implication between these variables and the control signal 10 can be derived from the existing literature (see, for example, the article “Design and simulation of self-tuning PID-type fuzzy adaptive control for an expert HVAC system” by Servet Soyguder, Mehmet Karakose, Hasan Alli, ELSEVIER, Expert Systems with Applications 36 (2009) 4566-4573 or the article “Self-Tuning Fuzzy PI Controller and its Application to HVAC Systems” by A. K. Pal and R. K. Mudi, INTERNATIONAL JOURNAL OF COMPUTATIONAL COGNITION (HTTP://WWW.IJCC.US), VOL. 6, NO. 1, MARCH 2008.

(36) Of course, without prejudice to the principle of the invention, the forms of embodiment and the implementation details may be extensively varied from those described and illustrated herein by way of non-limiting example, without however departing from the protection scope of the present invention as set out in the appended claims.