WO2017155472A1 - Procédé de commande d'une pluralité de ventilateurs disposés dans une zone pour fournir une commande de confort thermique, et dispositif associé - Google Patents

Procédé de commande d'une pluralité de ventilateurs disposés dans une zone pour fournir une commande de confort thermique, et dispositif associé Download PDF

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Publication number
WO2017155472A1
WO2017155472A1 PCT/SG2017/050119 SG2017050119W WO2017155472A1 WO 2017155472 A1 WO2017155472 A1 WO 2017155472A1 SG 2017050119 W SG2017050119 W SG 2017050119W WO 2017155472 A1 WO2017155472 A1 WO 2017155472A1
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WO
WIPO (PCT)
Prior art keywords
fans
target positions
operating parameters
air
desired air
Prior art date
Application number
PCT/SG2017/050119
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English (en)
Inventor
Schiavon STEFANO
Weng Khuen HO
Keck Voon LING
Shuo LIU
Le YIN
Original Assignee
The Regents Of The University Of California
National University Of Singapore
Nanyang Technological University
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Application filed by The Regents Of The University Of California, National University Of Singapore, Nanyang Technological University filed Critical The Regents Of The University Of California
Publication of WO2017155472A1 publication Critical patent/WO2017155472A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
    • F04D27/005—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids by changing flow path between different stages or between a plurality of compressors; Load distribution between compressors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D25/00—Pumping installations or systems
    • F04D25/16—Combinations of two or more pumps ; Producing two or more separate gas flows
    • F04D25/166—Combinations of two or more pumps ; Producing two or more separate gas flows using fans
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/72—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure
    • F24F11/74—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure for controlling air flow rate or air velocity
    • F24F11/77—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure for controlling air flow rate or air velocity by controlling the speed of ventilators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/30—Velocity
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Definitions

  • the present invention generally relates to a computer-implemented method of controlling a plurality of fans disposed in an area, and a device thereof, to provide thermal comfort control for a plurality of target positions in the area.
  • Elevated air speed generated by fans is an effective and energy- efficient method of cooling people in moderately warm indoor and outdoor environments.
  • Electric fans do not actually lower air temperature or air humidity to cool people as air conditioners do. They cool people only by increasing the air movement around people to make human body release heat faster.
  • This cooling approach can be used either in indoor environments to assist air conditioning system with higher cooling set-point or in public outdoor environments such as bazaars and hawker centers (open-air food centers), where air conditioning is not applicable.
  • Academic peer-reviewed research has demonstrated that personally controlled air movement using fans can maintain human thermal comfort in warm environments and strongly reduce energy usage.
  • U.S. Pat. No. 5,197,858 to Cheng describes a thermal control variable speed DC brushless fan which may change speed in accordance with the temperature sensed. The change in the fan's rotation speed relation to the temperature is almost linear under normal conditions.
  • U.S. Pat. No. 5,449,275 to Gluszek et al. describes a fan speed controller which is able to maintain a constant level of thermal comfort by varying a fan speed in response to dry bulb air temperature, relative air humidity, thermal radiation and distance between a human body and a fan.
  • U.S. Pat. No. 5,627,527 to Menta describes an apparatus and a method for thermostatically controlling the operation of a multiple speed fan and light assembly by inputting a desired temperature range and airflow direction for each fan speed and by inputting a single number for controlling the on time and duration of the light assembly.
  • U.S. Pat. No. 6,415,984 to Parker et al. describes a ceiling fan operation control for turning the fan on and off based on a passive infrared sensor, combined with a temperature sensor to regulate the speed of the fan.
  • none of the above-mentioned disclosures is applicable to a system of fans.
  • each fan usually operates individually.
  • a single fan or a system of fans may provide a significantly nonuniform air speed field.
  • people sitting at different positions may experience different air flow, and therefore, may experience different sensation of thermal comfort.
  • the configuration of the fans (e.g., number of fans and their placements) and their operation are also not optimized. As a result, some occupants may experience very weak or very strong airflow.
  • the operating parameters for the plurality of fans are optimized based on differences between the desired air speeds and measured air speeds at the plurality of target positions, respectively.
  • the method further comprises generating gain information based on the measured air speeds at the plurality of target positions and the operating parameters for the plurality of fans.
  • optimizing the operating parameters comprises minimizing a largest difference in said differences based on the gain information and the desired air speeds at the plurality of target positions.
  • optimizing the operating parameters comprises determining changes in the operating parameters for the plurality of fans to obtain the optimized operating parameters based on the gain information and the desired air speeds at the plurality of target positions, wherein the gain information comprises a plurality of gain values, each gain value derived based on a ratio of a change in the measured air speed at the corresponding target position to a change in the operating parameter of the corresponding fan.
  • the changes in the operating parameters are determined based on the equation:
  • V d V d — V(p)
  • V d the desired air speeds at the plurality of target positions
  • V(p) the measured air speeds at the plurality of target positions from the plurality of fans generating air movement based on the operating parameters P.
  • one or more of the desired air speeds are determined based on a thermal comfort model and a temperature measured at the area as an input to the thermal comfort model.
  • one or more of the desired air speeds are determined based on feedback received from one or more occupants at the corresponding one or more target positions.
  • the feedback comprises one or more of a first type of input indicating a desire to increase the air speed at the corresponding target position and/or one or more of a second type of input indicating a desire to decrease the air speed at the corresponding target position collected over a time period.
  • the operating parameter is a power parameter or a speed parameter for controlling the elevated air speed generated by the fan.
  • the device for controlling a plurality of fans disposed in an area to provide thermal comfort control for a plurality of target positions in the area, each of the plurality of fans being configured to generate air movement at an elevated air speed under the control of a fan control module based on an operating parameter, the device comprising:
  • a desired air speed determining module configured to determine desired air speeds at the plurality of target positions, respectively
  • an optimization module configured to optimize the operating parameter for each of the plurality of fans, the operating parameters for the plurality of fans being optimized collectively based on the desired air speeds at the plurality of target positions in the area.
  • the optimization module is configured to optimize the operating parameters for the plurality of fans based on differences between the desired air speeds and measured air speeds at the plurality of target positions, respectively.
  • the device further comprises a gain information generating module configured to generate gain information based on the measured air speeds at the plurality of target positions and the operating parameters for the plurality of fans.
  • optimizing the operating parameters comprises minimizing a largest difference in said differences based on the gain information and the desired air speeds at the plurality of target positions.
  • optimizing the operating parameters comprises determining changes in the operating parameters for the plurality of fans to obtain the optimized operating parameters based on the gain information and the desired air speeds at the plurality of target positions, wherein the gain information comprises a plurality of gain values, each gain value derived based on a ratio of a change in the measured air speed at the corresponding target position to a change in the operating parameter of the corresponding fan.
  • the changes in the operating parameters are determined based on the equation:
  • K denotes the gain matrix
  • ⁇ denotes said changes in the operating parameters P
  • AV ⁇ V d — V(p)
  • V d denotes the desired air speeds at the plurality of target positions
  • V(p) denotes the measured air speeds at the plurality of target positions from the plurality of fans generating air movement based on the operating parameters P.
  • the desired air speed determining module is configured to determine one or more of the desired air speeds based on a thermal comfort model and a temperature measured at the area as an input to the thermal comfort model.
  • the desired air speed determining module is configured to determine one or more of the desired air speeds based on feedback received from one or more occupants at the corresponding one or more target positions.
  • the feedback comprises one or more of a first type of input indicating a desire to increase the air speed at the corresponding target position and/or one or more of a second type of input indicating a desire to decrease the air speed at the corresponding target position collected over a time period.
  • the operating parameter is a power parameter or a speed parameter for controlling the elevated air speed generated by the fan.
  • a computer program product embodied in one or more computer-readable storage mediums, comprising instructions executable by one or more computer processors to perform the method of controlling a plurality of fans disposed in an area to provide thermal comfort control for a plurality of target positions in the area according to the first aspect of the present invention.
  • FIG. 1 depicts a flow diagram of a method of controlling a plurality of fans disposed in an area to provide thermal comfort control for a plurality of target positions in the area according to various embodiments of the present invention
  • FIG. 2 depicts a schematic drawing of a device for controlling a plurality of fans disposed in an area to provide thermal comfort control for a plurality of target positions in the area according to various embodiments of the present invention
  • FIG. 3 depicts a schematic block diagram of a system for providing thermal comfort control for a plurality of target positions in an area according to various example embodiments of the present invention
  • FIGs. 4A and 4B depict a picture of a meeting room (FIG. 4A) and the corresponding room layout (FIG. 4B), respectively, in which experiments were conducted according to various example embodiments of the present invention
  • FIG. 5 depicts a picture showing an air distribution measuring system used for sensing the room temperature and measuring air speed at the target positions in the experiments conducted according to various example embodiments of the present invention
  • FIGs. 6 A and 6B depict the relationship between air speed and fan power with respect to the linear function (FIG. 6A) and the natural logarithm function (FIG. 6B), respectively, obtained in experiments conducted;
  • FIGs. 7 A and 7B depict the relationship between air speed and fan speed setting with respect to the linear function (FIG. 7A) and the natural logarithm function (FIG. 7B), respectively, obtained in experiments conducted;
  • FIG. 9 depicts boxplots of the median values of measured air speeds before and after optimization obtained in experiments conducted.
  • FIG. 10 depicts boxplots of PMV deviation from target (i.e., actual PMV values minus target PMV values) before and after optimization obtained in experiments conducted;
  • FIG. 11 depicts a schematic block diagram of a system for providing thermal comfort control for a plurality of target positions in an area according to various example embodiments of the present invention;
  • FIG. 12 depicts a schematic drawing showing an illustrative framework for a SMS-based remote fan control system according to various example embodiments of the present invention
  • FIGs. 13A and 13B depict a lecture room layout (FIG. 13A) and a picture of the lecture room (FIG. 13B), respectively, in which experiments were conducted according to various example embodiments of the present invention
  • FIG. 13C depicts a timeline of an experiment conducted in the lecture room shown in FIGs. 13A and 13B;
  • FIGs. 14A and 14B depict the temperature (FIG. 14 A) and the relative humidity (FIG. 14B), respectively, measured by four HOBO temperature/relative humidity data loggers arranged in the lecture room as shown in FIG. 13A during the experiment;
  • FIG. 15 depicts a survey questionnaire used in the experiment for collecting occupants' feedback
  • FIGs. 16A and 16B show the overall thermal acceptability for two tested conditions in the experiment, in boxplots and in bar charts (dichotomous), respectively;
  • FIG. 17 shows the overall thermal sensation for the two tested conditions in the experiment in boxplots
  • FIGs. 18A and 18B show the overall acceptance of air movement for the two tested conditions in the experiment, in boxplots and in bar charts (dichotomous), respectively;
  • FIGs. 19A and 19B show the fan speed setting adjustments recorded in the experiment for fans 1 to 5 (FIG. 19A) and fans 6 to 10 (FIG. 19B) shown in FIG. 13 A, respectively;
  • FIG. 20 depicts a schematic drawing showing a device capable of being communicatively coupled to a control system configured to control a plurality of fans based on operating parameters.
  • Various embodiments of the present invention provide a method of controlling a plurality of fans (or interchangeably referred to as a system of fans herein) disposed in an area, and a device thereof, to provide thermal comfort control in the area, that seek to overcome, or at least ameliorate, one or more of the deficiencies associated with conventional methods/approaches of providing thermal comfort control in an area, such as those as described in the background.
  • a fan described herein may be any device or apparatus configured to produce air movement for providing a cooling effect on one or more subjects, including but not limited to, a fan with rotatable blades or a centrifugal fan, such as a blower, that produces a current of air.
  • Elevated air speed generated by fans is an effective and energy-efficient method of cooling people in moderately warm indoor and outdoor environments.
  • fans are not commonly incorporated into the building automation system (BAS) to save energy (e.g., by allowing the air conditioning system to operate at a higher setpoint) and improve comfort.
  • BAS building automation system
  • various embodiments of the present invention provide a method of controlling a system of fans disposed in an area to provide thermal comfort control in the area, such as to control a system of fans cooperatively (collectively) to generate elevated air speed (uniform or non-uniform) according to a thermal comfort model by using a linear programming algorithm/technique.
  • the method may be applied in either air conditioned spaces (area) such as office cubicles, theaters and classrooms, or non-air conditioned spaces such as hawker centers (open-air food centers) where fans may conventionally be provided in such spaces to operate at a particular speed setting.
  • air conditioned spaces area
  • non-air conditioned spaces such as hawker centers (open-air food centers)
  • fans may conventionally be provided in such spaces to operate at a particular speed setting.
  • the method/device may automatically determine the optimal fan speed settings (or fan power) based on the temperature(s) measured at the area.
  • the device may also advantageously be provided as a separate component to an existing BAS, but may be coupled or incorporated to the BAS to control the plurality of fans disposed in the area so as to provide thermal comfort control. Accordingly, for example, the method and device may be applied after the installation of the fans in the area. Accordingly, the method/device may advantageously enable low implementation costs (thus low investment required), thereby allowing ease of commercialization.
  • Various embodiments of the present invention may also facilitate in determining the configuration of the fans (e.g., the number of fans and their placements in an area).
  • method/device according to various embodiments of the present invention is capable of controlling a system of fans effectively and maintain or enhance thermal comfort while the air conditioner thermostat was set to a higher setpoint, thus advantageously saving energy.
  • FIG. 1 depicts a flow diagram of a method (computer-implemented method) 100 of controlling a plurality of fans disposed in an area to provide thermal comfort control for a plurality of target positions in the area according to various embodiments of the present invention.
  • each of the plurality of fans is configured to generate air movement at an elevated air speed based on (e.g., under the control of) an operating parameter.
  • the method 100 comprising a step 102 of determining desired air speeds at the plurality of target positions, respectively, and a step 104 of optimizing the operating parameter for each of the plurality of fans, the operating parameters for the plurality of fans being optimized collectively based on the desired air speeds at the plurality of target positions (e.g., target occupancy positions) in the area. Accordingly, with the optimized operating parameters, the elevated air speed generated by each of the plurality of fans may be optimized with respect to the plurality of target positions to provide improved thermal comfort control for the plurality of target positions.
  • the operating parameter may be a power parameter or a speed parameter (e.g., fan speed setting) for controlling the elevated air speed generated by the fan.
  • a speed parameter e.g., fan speed setting
  • the method is capable of controlling a plurality of fans in an area effectively to provide the desired air speeds at the target positions as best as possible to provide the occupants at such target positions with a satisfactory or pleasant level of thermal comfort.
  • the method may advantageously be adaptable to occupancy variation in the area such that the air speeds generated by the plurality of fans are specifically optimized at the target occupancy positions.
  • the method may further enable the air conditioning temperature setpoint to be adjusted higher, thus saving energy and reducing power usage costs.
  • the operating parameters for the plurality of fans are optimized based on differences between the desired air speeds at the plurality of target positions and measured air speeds at the plurality of target positions, respectively.
  • optimizing the operating parameters comprises minimizing a largest difference in such differences based on gain information and the desired air speeds at the plurality of target positions. This will be described in further details later below according to various example embodiments of the present invention.
  • the gain information (e.g., a gain matrix) may be generated based on the measured air speeds at the plurality of target positions and the operating parameters for the plurality of fans.
  • the gain information may be used to determine the air speeds at the plurality of target positions to the operating parameters (e.g., fans speed setting) for the plurality of fans such that the operating parameters may be optimized to minimize differences/deviations between the desired air speeds and the measured/actual air speed at the plurality of target positions (e.g., to minimize a largest difference in such differences).
  • one or more of the desired air speeds are determined based on a thermal comfort model and a temperature measured at the area as an input to the thermal comfort model.
  • the thermal comfort model may be a Predicted Mean Vote-Standard Effective Temperature (PMV-SET) model.
  • PMV-SET Predicted Mean Vote-Standard Effective Temperature
  • the present invention is not limited to applying the PMV-SET model for determining the desired air speeds at various target positions in the area based on a temperature measured at the area, and other models known in the art may be applied for determining the desired air speeds and are within the scope of the present invention.
  • one or more of the desired air speeds are determined based on feedback received from one or more occupants at the corresponding one or more target positions.
  • the feedback may comprise one or more of a first type of input (e.g., "+” symbol) indicating a desire to increase the air speed at the corresponding target position and/or one or more of a second type of input (e.g., "-" symbol) indicating a desire to decrease the air speed at the corresponding target position collected over a time period (e.g., a regular optimization time period, such as every 2 minutes).
  • FIG. 2 depicts a schematic drawing of a device 200 (e.g., corresponding to the method 100 as described hereinbefore with reference to FIG. 1) for controlling a plurality of fans disposed in an area to provide thermal comfort control for a plurality of target positions in the area.
  • each of the plurality of fans is configured to generate air movement at an elevated air speed based on (e.g., under the control of) an operating parameter.
  • the device 200 comprises a desired air speed determining module/circuit 202 configured to determine desired air speeds at the plurality of target positions, respectively, and an optimization module/circuit 204 configured to optimize the operating parameter for each of the plurality of fans, the operating parameters for the plurality of fans being optimized collectively by the optimizing module based on the desired air speeds at the plurality of target positions in the area.
  • the device 200 may further comprise a computer processor 206 capable of executing computer-executable instructions (e.g., the desired air speed determining module 202 and the optimization module 204) to perform one or more functions or methods (e.g., to optimize the operating parameter for each of the plurality of fans), and a computer-readable storage medium 208 communicatively coupled to the processor 206 having stored therein one or more sets of computer-executable instructions (e.g., the desired air speed determining module 202 and the optimization module 204).
  • a computer processor 206 capable of executing computer-executable instructions (e.g., the desired air speed determining module 202 and the optimization module 204) to perform one or more functions or methods (e.g., to optimize the operating parameter for each of the plurality of fans), and a computer-readable storage medium 208 communicatively coupled to the processor 206 having stored therein one or more sets of computer-executable instructions (e.g., the desired air speed determining module 202 and the optimization module 204).
  • the device 200 may be provided as a separate unit to a control system e.g., building automation system (BAS)) configured to control the plurality of fans (e.g., to generate air movement at an elevated air speed based on the operating parameters).
  • a control system e.g., building automation system (BAS)
  • BAS building automation system
  • the device 200 may be configured to be capable of being communicatively coupled (e.g., according to any wireless or wired protocol known in the art) to the control system for transmitting the optimized operating parameters thereto for the control system to control the plurality of fans based on the optimized operating parameters.
  • the device 200 may be integrated in the control system such that the control system may comprise the desired air speed determining module 202 and the optimization module 204 executable by one or more computer processors of the control system to perform one or more functions or methods as described herein.
  • the control system may thus constitute the device 200 for controlling a plurality of fans disposed in an area to provide thermal comfort control.
  • the device 200 may be configured to be capable of being communicatively coupled (e.g., according to any wireless or wired protocol known in the art) to each of the plurality of fans so as to control the plurality of fans (e.g., directly) based on the operating parameters (e.g., optimized operating parameters) communicated thereto.
  • a computing system, a controller, a microcontroller or any other system providing a processing capability may be presented according to various embodiments in the present disclosure. Such a system may be taken to include one or more processors and one or more computer-readable storage mediums.
  • the device/system 200 described herein includes a processor (or controller) 206 and a computer-readable storage medium (or memory) 208 which are for example used in various processing carried out therein as described herein.
  • a memory or computer-readable storage medium used in various embodiments may be a volatile memory, for example a DRAM (Dynamic Random Access Memory) or a non-volatile memory, for example a PROM (Programmable Read Only Memory), an EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), or a flash memory, e.g., a floating gate memory, a charge trapping memory, an MRAM (Magnetoresistive Random Access Memory) or a PCRAM (Phase Change Random Access Memory).
  • DRAM Dynamic Random Access Memory
  • PROM Programmable Read Only Memory
  • EPROM Erasable PROM
  • EEPROM Electrical Erasable PROM
  • flash memory e.g., a floating gate memory, a charge trapping memory, an MRAM (Magnetoresistive Random Access Memory) or a PCRAM (Phase Change Random Access Memory).
  • a “circuit” may be understood as any kind of a logic implementing entity, which may be special purpose circuitry or a processor executing software stored in a memory, firmware, or any combination thereof.
  • a “circuit” may be a hard-wired logic circuit or a programmable logic circuit such as a programmable processor, e.g. a microprocessor (e.g. a Complex Instruction Set Computer (CISC) processor or a Reduced Instruction Set Computer (RISC) processor).
  • a “circuit” may also be a processor executing software, e.g. any kind of computer program, e.g. a computer program using a virtual machine code, e.g. Java.
  • a “module” may be a portion of a system according to various embodiments in the present invention and may encompass a “circuit” as above, or may be understood to be any kind of a logic-implementing entity therefrom.
  • the present specification also discloses a system or an apparatus for performing the operations/functions of the methods described herein.
  • a system or apparatus may be specially constructed for the required purposes, or may comprise a general purpose computer or other device selectively activated or reconfigured by a computer program stored in the computer.
  • the algorithms presented herein are not inherently related to any particular computer or other apparatus.
  • Various general-purpose machines may be used with computer programs in accordance with the teachings herein.
  • the construction of more specialized apparatus to perform the required method steps may be appropriate.
  • the present specification also at least implicitly discloses a computer program or software/functional module, in that it would be apparent to the person skilled in the art that the individual steps of the methods described herein may be put into effect by computer code.
  • the computer program is not intended to be limited to any particular programming language and implementation thereof. It will be appreciated that a variety of programming languages and coding thereof may be used to implement the teachings of the disclosure contained herein.
  • the computer program is not intended to be limited to any particular control flow. There are many other variants of the computer program, which can use different control flows without departing from the spirit or scope of the invention.
  • modules described herein may be software module(s) realized by computer program(s) or set(s) of instructions executable by a computer processor to perform the required functions, or may be hardware module(s) being functional hardware unit(s) designed to perform the required functions. It will also be appreciated that a combination of hardware and software modules may be implemented.
  • one or more of the steps of the computer program/module or method may be performed in parallel rather than sequentially.
  • Such a computer program may be stored on any computer readable medium.
  • the computer readable medium may include storage devices such as magnetic or optical disks, memory chips, or other storage devices suitable for interfacing with a general purpose computer.
  • the computer program when loaded and executed on such a general-purpose computer effectively results in an apparatus that implements the steps of the methods described herein.
  • a computer program product embodied in one or more computer-readable storage mediums (non-transitory computer- readable storage medium), comprising instructions (e.g., the desired air speed determining module 202 and the optimization module 204) executable by one or more computer processors to perform a method 100 of controlling a plurality of fans disposed in an area to provide thermal comfort control as described hereinbefore with reference to FIG. 1 or other method(s) described herein.
  • instructions e.g., the desired air speed determining module 202 and the optimization module 204
  • various computer programs or modules described herein may be stored in a computer program product receivable by a computer system or electronic device (e.g., device 200) therein for execution by a processor of the computer system or electronic device to perform the respective functions.
  • the software or functional modules described herein may also be implemented as hardware modules. More particularly, in the hardware sense, a module is a functional hardware unit designed for use with other components or modules. For example, a module may be implemented using discrete electronic components, or it can form a portion of an entire electronic circuit such as an Application Specific Integrated Circuit (ASIC). Numerous other possibilities exist. Those skilled in the art will appreciate that the software or functional module(s) described herein can also be implemented as a combination of hardware and software modules.
  • ASIC Application Specific Integrated Circuit
  • the operating parameters for the system of fans are optimized collectively based on desired air speeds at the target occupancy positions, whereby such desired air speeds are determined based on a thermal comfort model (e.g., the integrated PMV-SET model or other appropriate thermal comfort model) and using linear programming algorithm/technique.
  • a thermal comfort model e.g., the integrated PMV-SET model or other appropriate thermal comfort model
  • Various example embodiments of the present invention may provide calibration of the system of fans in the actual environment.
  • the air speed field generated by fans depends on various parameters (e.g. air temperature, furniture layout, interaction between fans, and so on). Therefore, the process of calibration is a significant advantage because the air flow field generated by the fan may not be predicted in the design phase in a cost-efficient manner.
  • Various example embodiments of the present invention may provide optimization of the operation of fans in the actual environment with or without knowing the occupancy information. For example, if positions of occupants can be detected, only the occupied positions may be considered in optimizing the operating parameters for the plurality of fans. Otherwise, all the calibrated target positions may be considered.
  • the optimal operation of the fans depends on the measured temperature at the area being subjected to thermal comfort control, which can be either the dry-bulb air temperature or the operative temperature.
  • thermal comfort control which can be either the dry-bulb air temperature or the operative temperature.
  • an optimization technique is used to obtain the most desirable air flow for the comfort of occupants. This is achieved according to various example embodiments by minimizing the worst-case deviation of the measured air speeds from the desired air speeds at the plurality of target occupancy positions in the area, respectively.
  • Thermal comfort may be assessed with the PMV-SET model, but as mentioned hereinbefore, other thermal comfort models may also be used.
  • quantification of the effect of operating parameters e.g., fans speed settings
  • the thermal comfort model e.g., the PMV-SET model
  • various example embodiments of the present invention may also determine the configuration of fans (e.g., number of fans and their placements) for facilitating the method of controlling the plurality of fans described herein to achieve the desired air speeds (e.g., as close as possible) at the plurality of target positions in the area.
  • various example embodiments of the present invention may provide automatic re-optimization of the operation of the fans (i.e., their operating parameters such as fan power or fan speed setting) to handle or adapt to occupancy variation.
  • the occupancy information e.g., locations/positions of occupants
  • the operating parameters for the plurality of fans may be re- optimized collectively based on desired air speeds at such locations/positions of occupants detected.
  • FIG. 3 depicts a schematic block diagram of a system 350 for providing thermal comfort control for a plurality of target positions in an area according to various example embodiments of the present invention.
  • the system 350 comprises a plurality of fans 320 disposed in the area and a device 300 for controlling the plurality of fans 320 to provide thermal comfort control for the plurality of target positions in the area.
  • Each of the plurality of fans 320 being configured to generate air movement at an elevated air speed based on an operating parameter.
  • the desired air speeds at the plurality of target positions are determined based on a thermal comfort model and a temperature measured at the area as input to the thermal comfort model.
  • a PMV-SET model is applied in the device 300 for determining the desired air speeds.
  • the device 300 is configured to receive a temperature (e.g., sensed/measured temperature) as an input (e.g., the only input to the device 300), which can be either the dry-bulb air temperature or the operative temperature, and is configured to output optimized operating parameters (e.g., optimized fans speed settings) to the plurality of fans 320.
  • a temperature e.g., sensed/measured temperature
  • optimized operating parameters e.g., optimized fans speed settings
  • the plurality of fans 320 may thus generate optimal air speeds after the optimal fans speed settings are applied.
  • a gain information generating module 306 (shown as "Calibration Process" in FIG. 3) is provided in the device 300 for generating gain information (e.g., a gain matrix) based on the measured air speeds at the plurality of target positions and the operating parameters for the plurality of fans.
  • the gain information generating module 306 may be configured to determine the gains of the air speeds to the operating parameters (fans speed settings) at different/various positions in the area where the occupants are or expected to be located (i.e., target occupancy positions). Accordingly, calibration of the system of fans in the actual environment is performed.
  • a desired air speed determining module 302 (shown as "PMV-SET Model" in FIG. 3) is provided in the device 300 for determining the desired air speeds at the plurality of target positions, respectively.
  • the desired air speed determining module 302 may be configured to determine the desired air speeds at a given temperature (temperature measured/sensed) using an integrated PMV-SET model.
  • An optimization module 304 (shown as "Linear Programming Optimizer" in FIG. 3) is provided in the device 300 for optimizing the operating parameters for the plurality of fans collectively based on the desired air speeds from the desired air speed determining module 302 and the gain information from the gain information generating module 306. Therefore, the optimization module 304 may be configured to consider/assess the differences/deviations of the measured/actual air speeds from the desired air speeds for all target positions (e.g., for all the occupants), and then cooperatively/collectively controls/manipulates the system of fans 320 to minimize the worst-case difference/deviation (i.e., minimize the largest difference/deviation).
  • the optimized operating parameters may then be sent to the system of fans 320 for controlling the system of fans 320 so as to optimize their elevated air speeds (V op t) with respect to the target positions to provide improved thermal comfort control for the target positions.
  • Thermal comfort is the condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation.
  • the most common approach used nowadays to predict thermal comfort for the purpose of building design is to correlate the results of psychological experiments to thermal analysis variables.
  • PMV Predicted Mean Vote
  • the human body employs physiological processes (e.g. sweating, shivering, regulating blood flow to the skin) in order to maintain a balance between the heat produced by metabolism and the heat loss from the body (e.g., see Charles K. E, "Fanger's Thermal Comfort and Draught Models", 2003, Institute for Research in Construction National Research Council of Canada, Ottawa, K1A 0R6, Canada IRC Research Report RR- 162, October 10, 2003).
  • physiological processes e.g. sweating, shivering, regulating blood flow to the skin
  • the heat loss from the body e.g., see Charles K. E, "Fanger's Thermal Comfort and Draught Models", 2003, Institute for Research in Construction National Research Council of Canada, Ottawa, K1A 0R6, Canada IRC Research Report RR- 162, October 10, 2003.
  • Fanger investigated in these physiological processes (e.g., see Fanger, P. O., "Calculation of Thermal Comfort, Introduction of a Basic Comfort Equation", ASHRAE transactions, 73(2), III-4, 1967) and indicated that the heat balance was most significantly influenced by mean skin temperature and sweat rate which depend on activity level. Combining these two factors with the heat balance equation, the PMV can be calculated as in ISO Standard 7730 (2005) by using the following equations:
  • M the metabolic rate, in watts per square metre (W/M 2 );
  • W the effective mechanical power, in watts per square metre (W/M 2 );
  • t a the air temperature, in degrees Celsius (°C);
  • t c j the clothing surface temperature, in degrees Celsius (°C);
  • t r the mean radiant temperature, in degrees Celsius (°C);
  • h c the convective heat transfer coefficient, in watts per square metre kelvin [W/(M 2 - K))];
  • I c j the clothing insulation, in square metres kelvin per watt (m 2 ⁇ K/W);
  • V the relative air speed, in metres per second (m/s).
  • the PMV value represents the average thermal sensation response (corresponding to ASHRAE thermal sensation scale) from a large group of people in a space.
  • There are six primary variables affecting the PMV value including four environmental variables: dry-bulb air temperature, mean radiant temperature, relative humidity, air speed and two personal variables: metabolic rate and clothing insulation.
  • the comfort zone may be defined by recommended limits of PMV values being from -0.5 to 0.5 where 80% occupants will be satisfied. Within the comfort zone, the higher satisfaction rate is expected when the PMV value is zero representing thermal neutrality, the PMV value being positive means slightly warm and being negative means slightly cold. Beyond the comfort zone, the thermal sensation may be regarded to be not acceptable.
  • the PMV model has been the standard method of predicting thermal comfort for occupants adopted by many organizations for standardization such as ASHRAE Standard 55 (ANSI/ASHRAE 2013), EN Standard 15251 (CEN 2007) and ISO Standard 7730 (ISO 2005).
  • Thermal Comfort Prediction Integrated PMV -SET Model
  • Air movement has a significant cooling effect, which increases the acceptable range of indoor temperatures. Since the PMV human heat balance model underestimates the influence of air movement, ASHRAE Standard 55-2013 adopts the Standard Effective Temperature (SET) index based on Gagge's two-node model of human temperature regulation to set a comfort zone for air movement at elevated air speed (see Gagge, A. P., "An effective temperature scale based on a simple model of human physiological regulatory response", ASHRAE Trans., 77, 247-262, 1971).
  • SET Standard Effective Temperature
  • the body is modeled as two concentric cylinders, the inner representing the body core and the outer representing the thin skin shell.
  • SET is defined as the equivalent air temperature of an isothermal environment at 50% relative humidity in which a subject, wearing clothing standardized for the activity concerned, has the same heat stress (skin temperature) and thermoregulatory strain (skin wettedness) as in the actual environment.
  • Isothermal environment refers to the environment at sea level, in which air temperature is equal to mean radiant temperature and the air is still.
  • the SET model reduces any combination of real environmental and personal variables into the temperature of the imaginary standard environment.
  • the above leads to the PMV-SET model (or Elevated Air Speed model) (see Schiavon, S. et al., "Web application for thermal comfort visualization and calculation according to ASHRAE Standard 55", In Building Simulation, Tsinghua University Press, Vol. 7, No. 4, pp. 321-334, August 2014), a two-step procedure comprising first using the PMV model to determine the comfort zone at the still-air region (V ⁇ 0.2 m/s) and then utilizing the SET index to extend the comfort zone to the elevated air speed region (V > 0.2 m/s).
  • the PMV-SET model is based on the idea that equal heat balance and skin wettedness for different air speeds can be plotted in terms of SET contours.
  • Each contour is a curve over a range of dry-bulb temperature, mean radiant temperature and air speed such that every point on this curve produces the same SET value.
  • Dry bulb temperature refers to the ambient air temperature. It may be referred to as “dry bulb” because the temperature is measured by a thermometer freely exposed to the air but shielded from radiation and moisture. If one starts with the underlying PMV comfort zone, these SET contours form the boundaries of an air-movement comfort zone (e.g., see Arens E. A. et al., "Moving air for comfort", ASHRAE Journal, 51(5): 18-29, 2009).
  • Equation (5) means that the adjusted average air temperature, (t a — CE), and adjusted mean radiant temperature, (t r — CE), at still air yields the same SET value as the actual average air temperature and actual mean radiant temperature do at elevated air speed.
  • Equation (5) can be solved by using the secant and bisection iterative algorithm.
  • the analytical comfort zone generated by the PMV-SET model is applicable when the occupants have activity levels that result in average metabolic rates between 1.0 and 2.0 met.
  • the air speed should be adjustable continuously or in maximum steps of 0.25 m/s in the range from still air, 0.2 m/s to 1.2 m/s, which is suitable for sedentary occupants.
  • relative humidity, metabolic rate and clothing insulation are set to be constant, and PMV value at every target occupancy position is set to be different values for different room temperatures.
  • the value of PMV may be limited within the range of 0 to 0.5 to avoid overcooling people.
  • the PMV value at each position can be set as zero.
  • the PMV may be set to be 0 at 26°C or below, 0.3 at 29°C, 0.5 above 29°C and intermediate values for temperatures between 26°C and 29°C.
  • the present invention is not limited to such PMV settings, and other PMV settings may be applied as desired or as appropriate. Optimization of Fans Operation
  • optimal operating parameters e.g., fans speed setting
  • the operating parameter may be described hereinafter as being the fans speed setting.
  • the operating parameter is not limited to fans speed setting and may be any parameter(s) controlling the air movement (in particular, elevated air speed) generated by the fan, such as the power parameter.
  • the optimal operating parameters for the system of fans are determined by minimizing the errors (differences or discrepancies) between desired air speeds and actual/measured air speeds at the target positions.
  • a minimax-error method/technique is applied, which minimizes the infinity- norm of the errors, that is, the largest absolute value of the errors.
  • the problem is formulated as to find the optimal fans speed setting, P opt , that minimizes the largest absolute error between the desired air speeds, V d , and the actual/measured air speeds, V(P), as follows:
  • Equation 7 Equation 7 where V d can be obtained from the PMV-SET model and P is the speed setting applied to the fans. In the example embodiments, a linear relationship between P and V(P) is assumed for substantial reduction in derivation complexity.
  • V d i and V d2 an example of one fan with speed setting, p, and two occupants located at different locations with desired air speeds, V d i and V d2 , respectively, will be described below before the general case is described.
  • Equation 9 Equation 9) where k x and k 2 are gains of vi and v 2 to p, respectively.
  • the optimal speed setting, p opt that minimizes the maximum error, ⁇ , may then be obtained by solving the following linear programming problem (e.g., see Norman, S. A., "Optimization of wafer temperature uniformity in rapid thermal processing systems", IEEE Transactions on Electron Devices, 1-46, 1991): Minimize [0 l] ⁇ J
  • Equation 18 Equation 18 where K is an m X n gain matrix, P is an n X 1 column vector and V is an m X 1 column vector.
  • Equation (18) The system in Equation (18) is overdetermined if m > n (more people than fans). In general, it will be appreciated that no exact value of P will exactly satisfy Equation (18).
  • the minimax-error solution P op t to the problem given in Equation (19) may be obtained by solving an equivalent linear programming problem given as:
  • Equation 20 Equation 20 where l t is a m X 1 column vector with all entries equal to one, ⁇ is a scalar, and where for vectors a and b, a ⁇ b indicates every entry of a is no more than the corresponding entry of b.
  • the above linear programming problem may be expressed as to find a minimum ⁇ * that satisfies
  • ⁇ ⁇ * , which is equivalent to the minimax-error problem stated in Equation (19).
  • optimizing the operating parameters comprises determining changes in the operating parameters for the plurality of fans to obtain the optimized operating parameters based on the gain information and the desired air speeds at the plurality of target positions.
  • the gain information comprises a plurality of gain values, each gain value derived based on a ratio of a change in the measured air speed at the corresponding target position to a change in the operating parameter of the corresponding fan.
  • Equation 21 Equation 21
  • V( P ) measured air speeds at the plurality of target positions from the plurality of fans generating air movement based on the operating parameters P
  • V d the more accurate the approximation Equation (21) will be.
  • the gain matrix K can be determined by measuring V(pW) through V(P ⁇ ), where each P® is P slightly perturbed by ⁇ , as follows
  • Equation (21) the optimization problem may then be formulated as:
  • K refers to the gain matrix (e.g., pre-calibrated gain matrix) comprising gain values, each gain value derived based on a ratio of a change in the measured air speed at the corresponding target position to a change in the operating parameter of the corresponding fan.
  • each gain value may be a ratio of change in air speed measured at the corresponding target position to adjustment in fan speed setting of the corresponding fan, for various different target positions.
  • AVd refers to the desired air speeds change obtained based on the PMV-SET model (or occupant feedback described hereinbefore and will be described further later below), and AP op t refers to changes in operating parameters, e.g., optimal fans speed settings adjustment that optimizes thermal comfort for occupants, obtained by solving (25).
  • the experiments were conducted in a meeting room at Nanyang Technological University.
  • the meeting room has a volume of 6.4 m x 5.0 m x 2.7m ⁇ 86.4 m 3 as shown in FIG. 4A, and four standing electric fans were employed to provide thermal comfort control of up to 12 occupants (up to 12 target occupancy positions) as shown in FIG. 4B.
  • the fan employed is a three-phase brushless direct current (DC) fan (Model FSAW98RI-A, Airmate, China), which provides 32-level speed settings.
  • the fan power ranges from 3.8 W to 32.5 W (see Table 2 below).
  • An air distribution measuring system AirDistSys5000, Sensor Electronics, Poland as shown in FIG.
  • the measurement range of temperature is between -10°C and +50°C with an accuracy of 0.2°C.
  • the measurement range of air speed is between 0.05 m/s and 5 m/s with an accuracy of ⁇ 0.02 m/s ⁇ 1.5% of readings.
  • each measurement takes 90 samples over 3 minutes in all the experiments conducted.
  • the axis of the fan blades and motor, and the sensors were placed at a height of 1.1m above the ground which is equal to the head height of a seated person according to thermal comfort standards. In this regard, it has been found that the head region is the dominant body part affecting overall comfort in warm environments. Linearity Verification
  • FIGs. 6A and 6B illustrate the relationship between air speed and fan power with respect to the linear function (FIG. 6A) and the natural logarithm function (FIG. 6B).
  • the average measured air speeds and fitted curves between air speed and fan power at different distances are plotted in FIGs. 6A and 6B.
  • the natural logarithm curves fit the measured data slightly better than the linear curves.
  • the mean absolute error (e ma ) and root mean square (RMS) error (e rms ) between measured data and fitted curves in fan power are summarized in Table 5 below.
  • FIGs. 7A and 7B illustrate the relationship between air speed and fan speed setting with respect to the linear function (FIG. 7A) and the natural logarithm function (FIG. 7B).
  • the average measured air speed and fitted curves between air speed and fan speed setting at different distances are plotted in FIGs. 7A and 7B. From FIG. 7B, at farther positions, it can be observed that the natural logarithm curves still fit the measured data very well. But at nearer positions within 2 m, both the mean absolute and RMS errors can be over 0.2 m/s as shown in Table 6 below. Table 6 provides the errors between the measured data and fitted curves in fan speed settings for mean absolute and RMS errors.
  • the thermal comfort at target positions was controlled to be maintained at a targeted level.
  • the fans were set to be in oscillation mode during the experiments.
  • oscillating air movement does not affect the thermal comfort or thermal sensation, but improves the air quality perception (e.g., see Pasut W. et al., "Enabling energy-efficient approaches to thermal comfort using room air motion", Building and Environment, 79, 13-19, 2014)
  • the calibration process e.g., by the gain information generating module 306 was conducted at all the 12 positions in the test environment shown in FIGs.
  • Equation (23) the gain matrix, K, was obtained as:
  • K is a 12 x 4 matrix referring to four fans being utilized to provide thermal comfort control for 12 occupants at target positions. It can be understood that the gains at certain positions are only used when these positions are occupied.
  • 8 out of 12 occupancy positions as labeled in FIG. 4B are selected/treated as occupied.
  • the typical value of business clothing insulation in the tropics is 0.7 clo (short sleeve button or polo shirt, long trousers, socks, business shoes plus chair insulation) and in more informal settings (e.g. at home) or outdoor (e.g. open-air food centers), people are expected to wear less clothes. With higher temperature setpoints, the clothing insulation is reduced as people are expected to dress according to the indoor climate. It will be appreciated by a person skilled in the art that such an assumption may be changed as appropriate to reflect the clothing actually worn by the occupants.
  • Relative humidity, rh is assumed to be 50%.
  • the desired air speeds calculated and other parameters based on the integrated PMV-SET model for the three categories are summarized in Table 7 below.
  • each box-and-whisker plot contains 90 measured samples that were taken at one position for 3 minutes using a 2-second sampling rate.
  • the line inside the box, the bottom line, and the top line shows the median, 25 th percentile and 75 th percentile of the samples, respectively.
  • the end of each whisker line represents the lowest/highest datum that is within 1.5 interquartile range (IQR) of the lower/upper quartile. Measurements beyond the end of a whisker are plotted as dots.
  • IQR interquartile range
  • Table 9 The medians (1st quartiles, 3rd quartiles) of measured air speed at each
  • FIG. 9 shows the boxplots of the median values of measured air speeds before (left) and after (right) optimization.
  • Each box-and-whisker plot corresponds to a column in Table 9 above, including all the 8 test positions information.
  • the air speeds at test positions are closer to the desired values after being optimized.
  • These data can be further converted into PMV deviation from the target PMV values (i.e., actual PMV values minus target PMV values) shown in FIG. 10.
  • the present method implemented in the experiments conducted is able to improve the thermal environment by keeping PMV deviations around zero under 26°C/79°F, 27.5°C/82°F and 29°C/84°F. This verifies/demonstrates that the present method implemented in the experiments conducted is advantageously able to generate the desired air speed at various target positions for thermal comfort under different room temperatures by using a system of fans.
  • FIG. 3 depicts a system 350 for providing thermal comfort control for a plurality of target positions in an area according to various example embodiments of the present invention for the case where the desired air speed is determined by a thermal comfort model, such as a PMV-SET model.
  • a thermal comfort model such as a PMV-SET model.
  • the present invention is not limited to the desired air speed at a target position being determined by a thermal comfort model, and other appropriate techniques for determining the desired air speed are also within the scope of the present invention.
  • the desired air speeds may be determined based on feedback received from one or more occupants at the corresponding one or more target positions.
  • the method may thus optimally and cooperatively manipulate/control a system of fans based on occupant feedback.
  • the optimal operating parameters e.g., optimal fan speed setting
  • the optimal operating parameters is determined according to occupants' preference by optimization technique and hence is able to provide individual thermal comfort.
  • various example embodiments of the present invention provide a method of generating elevated air speed (uniform or non-uniform) at target occupancy positions to improve human thermal comfort in indoor and outdoor environments by cooperatively/collectively controlling a system of electric fans based on occupant feedback.
  • the operating parameters for the system of fans are optimized collectively based on desired air speeds at the target occupancy positions, whereby such desired air speeds are determined based on occupant feedback and using linear programming algorithm/technique.
  • Various example embodiments of the present invention may provide interpretation of occupants' desire to have more or less air movement as air movement increment or decrement.
  • the optimal operation of fans depends on the occupant feedback which may include both the occupants' position and their desire to have more or less air movement.
  • an optimization technique is used to obtain the most desirable air flow for the comfort of occupants. This is achieved according to various example embodiments by minimizing the worst-case deviation of the measured air speeds from the desired air speed at the plurality of target occupancy positions in the area, respectively.
  • the feedback from the occupants may be collected via any form of data communication between devices/systems known in the art, such as but not limited to, short message service (SMS).
  • SMS short message service
  • automatic re-optimization of the operation of fans may occur when there is new feedback to achieve consensus and to adapt to occupancy variation.
  • FIG. 11 depicts a schematic block diagram of a system 1150 for providing thermal comfort control for a plurality of target positions in an area according to various example embodiments of the present invention.
  • the system 1 150 comprises a plurality of fans 320 disposed in the area and a device 1 100 for controlling the plurality of fans 320 to provide thermal comfort control for the plurality of target positions in the area.
  • Each of the plurality of fans 320 is configured to generate air movement at an elevated air speed based on an operating parameter.
  • the desired air speeds at the plurality of target positions are determined based on occupant feedback by the occupant feedback module 1102. As shown in FIG.
  • the device 1100 is configured to receive occupant feedback as an input (e.g., the only input to the device 1100), which may include the occupant position and the respective indication of their desire to have more or less air movement, and is configured to output optimized operating parameters (e.g., optimized fans speed settings) to the plurality of fans 320.
  • the plurality of fans 320 may thus generate optimal air speeds after the optimal fans speed settings are applied.
  • a gain information generating module 306 (shown as "Calibration Process" in FIG. 1 1) is provided in the device 1 100 for generating gain information (e.g., a gain matrix) based on the measured air speeds at the plurality of target positions and the operating parameters for the plurality of fans.
  • the gain information generating module 306 may be configured to determine the gains of the air speeds to the operating parameters (fans speed settings) at different/various positions in the area where the occupants are or expected to be located (i.e., target occupancy positions).
  • a desired air speed determining module 1102 (shown as "Occupant Feedback" in FIG. 11) is provided in the device 1100 for determining the desired air speeds at the plurality of target positions, respectively.
  • the desired air speed determining module 1102 may be configured to determine the desired air speeds by interpreting occupants' desire to have more or less air movement as air speed increment or decrement.
  • An optimization module 304 (shown as "Linear Programming Optimizer" in FIG. 11) is provided in the device 1100 for optimizing the operating parameters for the plurality of fans 320 collectively based on the desired air speeds from the desired air speed determining module 1102 and the gain information from the gain information generating module 306. Therefore, the optimization module 304 may be configured to consider/assess the differences/deviations of the measured/actual air speeds from the desired air speeds for all target positions (e.g., for all the occupants), and then cooperatively/collectively controls/manipulates the system of fans 320 to minimize the worst-case difference/deviation (i.e., minimize the largest difference/deviation).
  • the optimized operating parameters may then be sent from the optimization module 304 to the system of fans 320 for controlling the system of fans 320 so as to optimize their elevated air speeds (V op t) with respect to the target positions to provide improved thermal comfort control for the target positions.
  • Thermal comfort may be defined as the condition of mind that expresses satisfaction with the thermal environment and may be assessed by subjective evaluation.
  • the environmental conditions for human thermal comfort have been studied extensively and several published standards, such as ASHRAE 55, EN15251 and ISO 7730, are available for reference. These standards focus on specifying the ranges of indoor thermal environmental factors (air temperature, mean radiant temperature, humidity and air speed) and personal factors (activity and clothing) that are acceptable to a majority of occupants.
  • ASHRAE 55 recommends thermal conditions that are acceptable to at least 80% occupants.
  • SMS Short Message Service
  • FIG. 12 depicts a schematic drawing showing an illustrative framework for the SMS-based remote fan control system.
  • the system is not limited in its application to the particular arrangement/configuration as shown in FIG. 12 and that system may be modified according to various other embodiments or implemented in various other ways as appropriate without deviating from the scope of the present invention.
  • the system as shown in FIG. 12 is to demonstrate the effective creation of the desired air movement to satisfy the occupants by cooperatively manipulating the fans based on occupant feedback. Nevertheless, for the sake of clarity and illustration purposes, the data communication for transmitting the occupant feedback may be described hereinafter as being based on SMS. However, it will be appreciated by a person skilled in the art that the occupant feedback may be collected via any other form of data communication between devices/systems known in the art, e.g., smartphone APP or Internet GUI (Graphical User Interface).
  • FIG. 13 A shows the lecture room layout
  • FIG. 13B shows a photo of the lecture room with students occupying various seats.
  • FIG. 13C illustrates a timeline of the experiment conducted.
  • FIGs. 14A and 14B depict graphs showing air temperature (FIG. 14A) and relative humidity (FIG. 14B), respectively, measured by the four HOBO temperature/relative humidity data loggers arranging in the lecture room as shown in FIG. 13 A during the experiment.
  • an occupant can provide feedback comprising one or more of a first type of input indicating a desire to increase the air speed at the corresponding target position and/or one or more of a second type of input indicating a desire to decrease the air speed at the corresponding target position collected over a time period.
  • a first type of input indicating a desire to increase the air speed at the corresponding target position
  • a second type of input indicating a desire to decrease the air speed at the corresponding target position collected over a time period.
  • an occupant may send a message through the short message service on his phone giving his seat number and a '+' ("first type of input") or a '-' ("second type of input”) to indicate increasing or decreasing air- speed respectively.
  • a e.g., may be set to 0.05 m/s
  • the device i.e., the optimization module 204/304
  • the optimization module 204/304 optimizes the fan speed setting based on the desired air speed determined and the gain matrix K to obtain an optimal fan speed setting that minimizes the maximum deviation of the actual/measured air speed from the desired air speed.
  • the optimization module 204/304 may be configured to execute the following optimization algorithm to obtain the optimized fan speed settings.
  • n Number of occupants
  • the optimization process and fan speed setting adjustment may be repeated at a predetermined time interval, such as every 2 minutes.
  • the gain matrix K may be pre-calibrated by the gain information generating module 206/306 in the manner as described hereinbefore. As an example only, the gain matrix K generated in the experiment is provided below.
  • FIG. 13C The timeline of the experiment conducted is shown in FIG. 13C.
  • the survey questionnaire used is shown in FIG. 15.
  • the difference is significant (p ⁇ 0.001) since the operation of the fans was optimized based on that the occupants could request higher air speed in Session 2.
  • FIG. 19A fan 1 to 5 on the left side of FIG. 13A
  • FIG. 19B fan 6 to 10 on the right side of FIG. 13 A
  • the device 200/300/1100 described herein may be provided as a separate component/unit to a control system (e.g., BAS or Building Management System (BMS)) configured to control the plurality of fans to generate air movement at an elevated air speed based on the operating parameters.
  • a control system e.g., BAS or Building Management System (BMS)
  • BMS Building Management System
  • the device may be configured to be capable of being communicatively coupled (e.g., according to any wireless or wired protocol known in the art) to the control system for transmitting the optimized operating parameters thereto for the control system to control the plurality of fans based on the optimized operating parameters.
  • FIG. 20 depicts a schematic drawing showing such a device 2000/2001 capable of being communicatively coupled to a control system (computer system) 2010 configured to control a plurality of fans based on operating parameters.
  • the device 2000/2001 may be communicatively coupled to the control system 2010 via a LAN cable (e.g., Ethernet cable) 2020 shown in FIG. 20.
  • LAN cable e.g., Ethernet cable
  • the device 2000/2001 may be communicatively coupled to the control system 2010 according to any other forms of wireless or wired protocol known in the art, such as Wi-Fi, Bluetooth, or USB cable.
  • Wi-Fi Wireless Fidelity
  • the device 2000 may comprise a feedback acquisition and processing module 2002 (e.g., corresponding to the desired air speed determining module 202 or the occupant feedback module 1102 as described hereinbefore) configured to determine desired air speeds at a plurality of target positions, respectively, a gain matrix module 2006 (e.g., corresponding to the gain information generating module or calibration process module 306 as described hereinbefore) configured to generate gain information, a linear programming module 2004 (e.g., corresponding to the optimization module 204 or linear programming optimizer 304 as described hereinbefore) configured to optimize the operating parameters for the plurality of fans collectively based on the desired air speeds determined, and a control signal generation module 2008 configured to generate a control signal including the optimized operating parameters for transmitting to the control system 2010 to control the plurality of fans based on the optimized operating parameters.
  • a feedback acquisition and processing module 2002 e.g., corresponding to the desired air speed determining module 202 or the occupant feedback module 1102 as described hereinbefore
  • a gain matrix module 2006 e.g.
  • FIG. 20 also illustrates another device 2001, which is the same or similar to the device 2000, except that the desired air speeds at the plurality of target positions are determined using a thermal comfort model 2003, such as a PMV-SET model, as described hereinbefore with reference to FIG. 3.
  • a thermal comfort model 2003 such as a PMV-SET model, as described hereinbefore with reference to FIG. 3.
  • the desired air speeds at the plurality of target positions are determined based on the thermal comfort model 2003 and a temperature measured at the area as input to the thermal comfort model 2003.
  • various embodiments of the present invention provide a method of controlling a system of electric fans cooperatively to generate uniform or non-uniform elevated air speed for thermal comfort maintenance or enhancement.
  • the method according to various embodiments may provide thermal comfort control or optimized air movement control based on a cooperative scheduling approach of multiple electric fans which takes all the occupants into consideration and aims to make every occupant feel as comfortable as possible.
  • the method may interpret multiple occupant feedbacks as fan control signal.
  • the method may be applied to various types of electric fans such as ceiling fans, standing fans or wall fans.
  • the method may be applied indoors and outdoors.
  • the method may be applied in either air-conditioned spaces such as office cubicles, theaters and classrooms, or non-air-conditioned spaces such as open-air food centers where fans conventionally operate at a predetermined speed setting.
  • a method of calibrating the system of fans in the actual environment is provided.
  • the air speed field generated by fans may depend on various parameters (e.g. air temperature, furniture layout, interaction between fans, and so on).
  • the process of calibration may provide a significant advantage because the air flow field generated by the fan cannot be predicted in the design phase in a cost-efficient manner.
  • the calibration process of the method may assume a linear relationship between air speed generated by electric fans and the fan speed setting (or natural logarithm of fan input power).
  • the input power may be within the physical range of the fan.
  • the calibration process of the method may be a onetime work. Once the calibration is done, the relative positions between the fans and occupancy locations are fixed. Otherwise, the system can be recalibrated.
  • a method of optimization of the fans operation is provided to generate desired air speed in the actual environment depending on the measured temperature.
  • the method may automatically determine the optimal fans speed settings (or fan input power) to generate desired air speeds under different temperatures.
  • a method of quantification of the occupants' desire to have more or less air movement is provided as air movement increment or decrement.
  • the method may include a desired air speed determination method which quantifies the occupants' desire to have more or less air movement into levels by counting how many '+' or '-' each individual has sent in one optimization cycle. These levels are multiplied by a coefficient, a, to determine the desired air speed change for each individual.
  • the gain a may be set to 0.05 m/s by default, but other values may also be used as appropriate or desired. Accordingly, a method of optimization of the fans operation (fan speed setting or fan input power) to generate desired air speed in the actual environment according to occupant feedback is provided.
  • the method may be a minimax-error solution which aims at minimizing the worst-case deviation from the desired air speed to obtain the most desirable air flow for the comfort of occupants.
  • the method may include an optimization technique to minimize the worst-case deviation from desired air speed based on linear programming algorithm. For example, this can help address the case whereby the positions near to the fan need less air flow or the positions far from the fan need more air flow.
  • the method may include the input of a measured temperature (e.g., to the thermal comfort control model for determining the desired air speeds), which can be either the dry-bulb air temperature or the operative temperature.
  • a measured temperature e.g., to the thermal comfort control model for determining the desired air speeds
  • the method may include a desired air speed determination and thermal comfort assessing method, that is, the PMV-SET model.
  • the PMV-SET model Besides the measured temperature and desired air speed, other model parameters such as relative humidity, metabolic rate and clothing insulation may be predetermined.
  • the user may change the default/initial setting as desired or appropriate.
  • the PMV value may be set to be in the range of (0, 0.5) since overcooling may be unexpected.
  • other thermal comfort models may also be used.
  • the method may be able to generate either the uniform air flow if the PMV values at all target positions are set to be the same or the non-uniform air flow if the PMV values at target positions are different due to the customization for different preferences of occupants.
  • the method of fans operation optimization may be applied with or without knowing occupancy information. If positions of occupants can be detected, only the occupied positions may be considered. Otherwise, all the calibrated target positions may be considered.
  • a method of quantification of the effect of fans speed settings (or fan input power) on the thermal sensation through the PMV-SET model for positions of the occupants in the space is provided.
  • the method may include the input of occupant feedback which can be done by any means of communication between human and the present device/system.
  • the method may be able to generate different air flow for different occupants at different positions, according to different preferences of the occupants.
  • the method may be applied to the occupied positions.
  • minimum air flow can be designated to save energy. For example, this may help to control only some fans to switch on while others to shut down to advantageously save energy without compromising thermal comfort.
  • the method may include a re-optimization scheme that repeats the optimization process every few minutes, according to latest feedbacks. This can advantageously help to achieve consensus and address occupancy variation.
  • a method of determining the number of fans and their placements for moveable fans is provided in the design phase.
  • the air speed at a plurality of target positions is measured. If the measured air speed at certain positions is too small or too large and violates the requirement of thermal comfort, the number of fans could be decreased or increased accordingly or the placements of the fans could be adjusted to offset the impact.
  • the method may be configured to obtain the best or optimal relative positions between fans and occupancy locations to provide acceptable thermal sensation. For example, by trying different relative positions, the actual air speeds at target locations can be adjusted to the same as desired ones.
  • a method of automatic re-optimization of fans operation to deal with occupancy variation is provided if occupancy information is available.
  • the method of automatic re-optimization of fans operation may consider the occupants at present, regardless of the predetermined occupancy layout. For example, this may help to control only some fans to switch on while others to shut down to advantageously save energy without compromising thermal comfort.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

La présente invention concerne un procédé mis en œuvre sur ordinateur pour commander une pluralité de ventilateurs disposés dans une zone pour fournir une commande de confort thermique pour une pluralité de positions cibles dans la zone. Chacun de la pluralité de ventilateurs est configuré pour générer un mouvement d'air à une vitesse d'air élevée sur la base d'un paramètre de fonctionnement. Le procédé comprend la détermination des vitesses d'air souhaitées à la pluralité de positions cibles, respectivement, et l'optimisation du paramètre de fonctionnement pour chacun de la pluralité de ventilateurs, les paramètres de fonctionnement pour la pluralité de ventilateurs étant optimisés collectivement sur la base des vitesses d'air souhaitées à la pluralité de positions cibles dans la zone. L'invention concerne en outre un dispositif correspondant pour commander une pluralité de ventilateurs.
PCT/SG2017/050119 2016-03-11 2017-03-10 Procédé de commande d'une pluralité de ventilateurs disposés dans une zone pour fournir une commande de confort thermique, et dispositif associé WO2017155472A1 (fr)

Applications Claiming Priority (2)

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US201662307223P 2016-03-11 2016-03-11
US62/307,223 2016-03-11

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WO2017155472A1 true WO2017155472A1 (fr) 2017-09-14

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114838403A (zh) * 2022-06-10 2022-08-02 海信空调有限公司 空调器及空调器的舒适控制方法
WO2023236660A1 (fr) * 2022-06-10 2023-12-14 海信空调有限公司 Climatiseur, et procédé de commande de confort pour climatiseur

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4732318A (en) * 1986-01-17 1988-03-22 Osheroff Gene W Velocity controlled forced air temperature control system
US20050232753A1 (en) * 2003-03-20 2005-10-20 Huntair Inc. Fan array fan section in air-handling systems
US20100163633A1 (en) * 2008-12-30 2010-07-01 Aquante Llc Automatically Balancing Register for HVAC Systems

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4732318A (en) * 1986-01-17 1988-03-22 Osheroff Gene W Velocity controlled forced air temperature control system
US20050232753A1 (en) * 2003-03-20 2005-10-20 Huntair Inc. Fan array fan section in air-handling systems
US20100163633A1 (en) * 2008-12-30 2010-07-01 Aquante Llc Automatically Balancing Register for HVAC Systems

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114838403A (zh) * 2022-06-10 2022-08-02 海信空调有限公司 空调器及空调器的舒适控制方法
CN114838403B (zh) * 2022-06-10 2023-10-20 海信空调有限公司 空调器及空调器的舒适控制方法
WO2023236660A1 (fr) * 2022-06-10 2023-12-14 海信空调有限公司 Climatiseur, et procédé de commande de confort pour climatiseur

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