US20200271329A1

US20200271329A1 - Systems and methods for implementing an advanced energy efficient boiler control scheme

Info

Publication number: US20200271329A1
Application number: US16/800,021
Authority: US
Inventors: Nicholas E. AUMEN; Bryan C. HAAG
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-02-26
Filing date: 2020-02-25
Publication date: 2020-08-27
Also published as: WO2020176551A1

Abstract

Automated systems, methods, techniques, processes, products and product components are provided to implement an advanced and energy efficient hot water heating system control scheme that incorporates an advanced hot water reset for the boilers, including condensing boilers in hydronic systems. The advanced controls are provided to substantially enhance combustion (heating) efficiency for the boilers. The disclosed schemes replace conventional linear hot water reset with a device which can stand alone or integrate with boiler control technology or an existing building automation system to create a unique (non-linear) boiler reset curve based on various inputs. The schemes allow boiler control systems to learn and adapt over time maximizing the efficiency of a condensing boiler plant, by providing an independent, intelligent, economical, monitorable and manipulable solution eliminating the need of a head end BAS control system.

Description

BACKGROUND

This application claims priority to U.S. Provisional Patent Application No. 62/810,385, entitled “Systems and Methods For Implementing an Advanced Energy Efficient Boiler Control Scheme,” by Nicholas E. Aumen and Bryan Haag, filed in the U.S. Patent and Trademark Office on Feb. 25, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.

FIELD OF THE DISCLOSURE

This disclosure is directed to exemplary embodiments of automated systems, methods, techniques, processes, products and product components that implement an advanced and energy efficient hot water heating system control scheme that incorporates an advanced hot water reset for the boilers, including condensing boilers in hydronic systems, being controlled to enhance combustion (heating) efficiency for the boilers.

DESCRIPTION OF THE RELATED ART

Environmental control systems for buildings take many forms. Certain heating systems for large buildings include certain heating systems that fall under the general category of hydronic heating systems generally employing liquid heat-transfer mediums in the heating systems. The working fluid is typically water or steam. Hydronic heating systems may include both heated water or steam loops to provide the heating medium. Large scale installations may range from hot water boilers in individual buildings to what may be referred to as “campus hot water systems” in which multiple buildings are fed hot water from a central plant and/or a central steam system is provided where the buildings are fed steam and the steam is converted to hot water in the individual buildings. Commonly, hot water heating systems are provided in which the hot water, as the heat supplying medium, is circulated through piping systems associated with one or more hot water boilers. The hot water boilers may typically be fired with combustible fuels, or may employ electric heating or heating using certain renewable energy sources.
In some conventional boiler systems, as in other typical heating systems for environmental control within buildings, a thermostat in a portion of the building signals a call for heat to a particular environmental zone within the building where the thermostat is located. The hot water circulation systems associated with the one or more boilers are activated to circulate a supply of hot water to the particular environmental zone within the building. Though thermostats are typically employed, it should be noted that some buildings may not employ conventional thermostats to activate the hot water circulation systems. In these buildings, the pumps in the hot water circulation systems may be simply started at a certain outside ambient air temperatures, and use a linear reset to control the water temperature. When the temperature of the circulating water is determined to fall below a preset lower temperature limit, the burner, or other heating element, associated with a particular boiler will receive an automated signal to fire, or energize, in order to heat the water in the boiler to a temperature limit set point. When the temperature of the circulating water reaches the temperature limit set point, the burner, or other heating element, shuts off and the hot water continues to circulate until the demand for heat from the calling thermostat is met.
The scheme of boiler control necessary to support the demand for a supply of hot water may involve multiple burner on/off cycles, and/or modulation of filing rate(s). Once the heat demand is satisfied, the boiler remains non-activated, and is thus allowed to cool, ultimately potentially to the ambient temperature of its surroundings. Ambient temperatures significantly affect the operations of the boilers. In low ambient temperatures, the demand for high temperature water likely keeps the periods of non-activation of the boiler to a minimum, thereby maintaining the boiler at a temperature well above ambient. Conversely, operations in more temperate surroundings may waste energy in forcing the boiler to “overheat” the water in consideration of the demand, cycling the burner cycles and the ultimate temperature of the boiler much less efficiently. In this manner, significant overall inefficiencies in the operation of the boiler system are introduced.
The addition of a reset controller to the boiler control system introduces a level of automated control that is intended to reduce these inefficiencies in boiler operations. A boiler temperature limit is automatically adjusted (or “reset”) based on the outside ambient air temperature in a manner that is theoretically designed to attempt to more closely approximate (or otherwise match) the supply of energy via the boiler to the anticipated demand for hot water necessary to achieve building occupant comfort in a comparatively more controlled manner.
Boiler reset or hot water reset schemes, therefore, are forms of energy-saving automatic control algorithms for the hot water boilers that are typically fired with fuel oil or natural gas, but are also applicable to boilers that employ other heat sources. A boiler reset or hot water reset control loop measures the outside air temperature. Information regarding the outside air temperature is used to estimate demand for heating load as the outside air temperature varies. The supply hot water temperature is modulated up and down range conventionally in an inverse linear ratio with respect to outside ambient air temperature.
The conventional standard, or generally accepted industry standard, for a boiler reset or hot water reset is a linear reset. A linear reset control scheme dictates a range of hot water supply temperatures across a corresponding range of ambient outside air temperatures using a linear scale, typically between, for example, a 180° F. hot water supply temperature at a 0° F. outside ambient air temperature, and a 120° F. hot water supply temperature at a 60° F. outside ambient air temperature. Typically, a lower level temperature can vary based on equipment type, building type, and other factors. Regardless of any particular “low level” setpoint, there remains a linear relationship.
These types of linear reset control strategies have existed for decades. The automated algorithms are straightforward, and thus limited in their inability to, for example, take advantage of modern intelligent system components and/or digital control equipment and sensors that exist today. In addition to the inability to adapt linear reset control systems to incorporate the enumerated advancing technologies, an additional shortfall exists in the employment of linear reset strategies based on their limited applicability to non-condensing boilers.

SUMMARY OF DISCLOSED EMBODIMENTS

In view of any one or more of (1) advances in system sensors, system control components, including digital controls and intelligent equipment design, (2) a challenge to constantly increase efficiencies in environmental control systems, and (3) an understanding of limitations in further efficiencies that may be realized given the dated nature of the conventional linear reset techniques, it may be advantageous to introduce uniquely updated and contemporary boiler control systems, algorithms, and system control components, and to implement associated methods, for advanced non-linear hot water reset for boilers.
In exemplary embodiments of the systems and methods according to this disclosure, it may be advantageous to implement certain schemes that allow modern digital building control systems, and advanced control for boilers, whereby a supply water temperature needed to meet space environmental comfort requirements is determined in a manner that maximizes combustion efficiency of the boilers. Such control schemes may, in embodiments, result in increased comfort for building occupants through advanced control of the environmental control systems. It is anticipated further that, through implementation of exemplary embodiments of the disclosed schemes, significant cost savings may be realized based on the efficiencies introduced according to the disclosed schemes over conventional linear hot water reset techniques. In the disclosed operating schemes and scenarios, advanced reset controls may significantly affect occupant comfort within building and overall efficiency of the controlled heating systems themselves.
In embodiments, systems and methods according to the disclosed embodiments may modify (lower) supply water temperatures for condensing and non-condensing boilers in a manner that realizes significant efficiencies.
Exemplary embodiments of the disclosed systems and methods may provide standalone control via a control standalone device, capable of more efficient operations without the comparatively higher cost of a modern digital building automation system (BAS) infrastructure, or necessary compatibility with, and incorporation into a BAS scheme. Other embodiments may access and use information available from the BAS in a manner that allows the implemented control schemes according to this disclosure to make intelligent decisions to maximize boiler efficiencies. In embodiments, the disclosed systems and methods may piggy-back onto, or otherwise supplement (or be supplemented by) BAS data.
Exemplary embodiments of the disclosed systems and methods may monitor multiple parameters including one or more of supply and return water temperatures, pump speed, hot water flow rates, and loop differential pressure, in addition to outside ambient air temperatures. The disclosed schemes may employ these additional multiple inputs to calculate new hot water temperature set points to a much finer granularity than is conventionally available using only outside ambient air temperature and a linear reset model.
In embodiments, the disclosed systems and methods may additionally reference boiler efficiency based on, for example, boiler firing (heating) curves that may be supplied by a boiler manufacturer. Embodiments implementing the disclosed schemes may compare boiler efficiencies with supply water temperature set points to optimize operation of the environmental control systems by, for example, controlling the boiler to perform at a peak efficiency across a range of operating parameters and environmental conditions.
In embodiments, the disclosed systems and methods may compute a new supply water temperature set point. This newly computed supply water temperature set point may be communicated to the building control system or the boiler control system, as appropriate, to reset the hot water supply temperature to the boiler thereby resulting in increased efficiencies in boiler operations.
These and other features, and advantages, of the disclosed systems and methods are described in, or apparent from, the detailed description of various exemplary embodiments provided below.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary embodiments of automated systems, methods, techniques, processes, products and product components that implement an advanced and energy efficient hot water heating system control scheme that incorporates an advanced hot water reset for the boilers, including condensing boilers in hydronic systems, being controlled to enhance combustion (heating) efficiency for the boilers, according to this disclosure, will be described, in detail, with reference to the following drawings, in which:

FIG. 1 illustrates a block diagram of an exemplary embodiment of an enhanced boiler-based environmental control system including an automated advanced hot water reset implementing device according to this disclosure;

FIG. 2 illustrates a block diagram of an automated advanced hot water reset implementing system according to this disclosure; and

FIG. 3 illustrates a flowchart of an exemplary method for implementing an automated scheme for implementing an advanced and efficient boiler control scheme according to this disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

The systems and methods for implementing an advanced energy efficient boiler control scheme according to this disclosure may generally replace conventional linear hot water reset controls with advanced systems, devices and methods that can stand alone or integrate with boiler control technology, or an existing building automation system.
In embodiments, the disclosed systems, methods, devices, techniques and schemes implement an updated control methodology to generate new, advanced and unique boiler reset curves based on various inputs.
In embodiments, the disclosed schemes may allow the system to learn and adapt over time to maximize an efficiency of a condensing boiler plant. When incorporated into existing boiler systems without a BAS, embodiments of the disclosed systems and methods may provide an independent, intelligent solution at a comparatively lower price point when compared to a BAS, thereby potentially eliminating a need, for example, for a head end control system while providing a user with an intelligent interface, which may be in a form of a control system dashboard, to monitor, evaluate, and change heating plant operation.
The disclosed systems, system components, devices, methods, processes and/or techniques for implementing an advanced energy efficient boiler control scheme may generally refer to these specific utilities for the disclosed systems, system components, devices, methods, processes and/or techniques, which may be applicable to both condensing and non-condensing boilers.
Exemplary embodiments described and depicted in this disclosure should not be interpreted, however, as being specifically limited to any particular configuration of a system, device, set of integrated electro-mechanical components, associated sensor elements/arrays, and/or decision-making programs and/or methodologies to accomplish the above-described functions. Any particular configuration of an automated control system for implementing a control scheme incorporating multiple monitored parameter inputs for environmental control within a building, and specifically for boiler control, that may benefit from the overarching concepts outlined according to the exemplary embodiments discussed in this disclosure is contemplated as being included within the scope of this inventive concept. In other words, it should be recognized that any advantageous use of advanced schemes for controlling boiler operations, including through the monitoring of supply (outlet) and return (inlet) water temperatures, outdoor ambient air temperatures, pump speed, hot water flow rates, and/or loop differential pressure, that may employ all, or a portion of, the devices and/or methods presented in this disclosure is contemplated as being included within the scope of the disclosed exemplary systems and methods.
The disclosed systems and methods will be described as being particularly adaptable for use in controlling operations of fuel or gas fired boilers (both condensing and non-condensing boilers) for supplying hot water through circulating systems to heat buildings, or portions thereof. This description, and the associated references, are intended to provide a single particular real-world use case in which the systems and methods according to this disclosure may be particularly beneficially adapted for use. These references are intended to be illustrative only and should not be considered as limiting the disclosed systems and methods to any particular embodiment, application, operational scenario, heat/heating source or use case. Generic reference will be made to comparative increases in efficiency over conventional linear reset methods for hot water reset in boiler systems as illustrative of the comparative advantages in efficiency and optimization of operations of the boiler systems that may be achieved through full implementation of the disclosed schemes within buildings, systems of buildings and other structures in which circulating hot water environmental control systems may be employed.
The disclosed exemplary systems and methods may, in a most basic and straightforward implementation, monitor, and use as inputs to the disclosed control scheme: supply water temperature measured in, or at an outlet of, a boiler; return water temperature measured in a vicinity of an inlet to the boiler; a rate of circulating flow for the water supply, which may be based on a pump speed; and an outside ambient air temperature. The combination of these inputs may be used to generate an output signal to the building automated system, or to the boiler control system or its components, to indicate a desired hot water supply temperature. Improving the reset curve by, for example, lowering the supply temperature, or constantly feeding the computed supply temperature to the control systems, particularly when using condensing boilers, may improve the efficiency of the boilers over conventional methods, and result in increasingly efficient systems and lower operational costs.
FIG. 1 illustrates a block diagram 100 of an exemplary embodiment of an enhanced boiler-based environmental control system including an automated advanced hot water reset implementing device 170 according to this disclosure.
As shown in FIG. 1, the enhanced boiler-based environmental control system may include one or more boilers 110, each of which may include one or more heating elements that is selectively energized or activated to heat a fluid medium, including generating hot water, to be circulated through system piping 140 in flow direction A. The one or more boilers 110 may be, for example, fuel-fired or gas-fired, or heated by electrical components.
In the boiler 110, water is heated to a preset temperature and leaves the boiler 110 via an outlet 112 for circulation through the system piping 140 in flow direction A, the circulation being facilitated, or urged, by one or more circulating pumps 120.
An outlet (supply) water temperature sensor 130 may be provided in the system piping 140 positioned downstream of the outlet 112 in the flow direction A, or downstream of the one or more circulating pumps 120 in the flow direction A.
An inlet (return) water temperature sensor 150 may be provided in the system piping positioned upstream, including proximately upstream, of a return water inlet 114 to the boiler 110.
An automated advanced hot water reset implementing device 170 may be provided. The automated advanced hot water reset implementing device 170 may receive signal inputs from one or more sensors. The sensors may include operation sensor(s) associated with the one or more circulating pumps 120 that may generate a signal input 125; outlet (supply) water temperature sensor(s) 130 that may generate a signal input 135; inlet (return) water temperature sensor(s) 150 that may generate a signal input 155; and outside ambient air temperature sensor(s) 160 that may generate signal input 165. The automated advanced hot water reset implementing device 170 may weight the various input values and/or apply an implementing scheme combining the various input values as an output signal 175. In embodiments, for example, if it is determined that, for a particular building, that building's setpoint may be more substantially affected by outside ambient air temperature, the automated advanced hot water reset implementing device 170 may more heavily weight signal input 165. These weighting adjustments may serve to allow varying installations of the automated advanced hot water reset implementing device 170 among significantly different buildings, in significantly different climates, to be appropriately locally adjusted. The output signal 175 from the automated advanced hot water reset implementing device 170 may cause the boiler to fire (or to be otherwise heated) in a manner that in turn heats the water to a specified setpoint in order to maintain a particular temperature of outlet (supply) water.
The application of the disclosed scheme by the automated advanced hot water reset implementing device 170 based on signal inputs 125, 135, 155 and 165 may have a measurable effect with regard to operational efficiency and cost savings when employed in conjunction with a condensing boiler. Similar results may be realized from application of the disclosed scheme by the automated advanced hot water reset implementing device 170 in association with non-condensing boilers as well.
It should be noted that, while the output signal 175 from the exemplary system is described above as going to the boiler to cause the boiler to fire (or to be otherwise heated) in a manner that heats the water to a specified setpoint in order to maintain a particular temperature of outlet (supply) water, being thereby indicative of a hot water setpoint, the output signal 175 should not be considered to be so limited. In embodiments, for example, the output signal 175 may include commands for operation and speed control of the one or more circulating pumps 120. Further, the output signal 175 may be sent directly to the involved components, or may be transmitted via a digital building automation system to each of the involved components.
Further, the above list of sensed parameters is not exhaustive. It is anticipated that, as systems expand, particularly with regard to the use of embedded or attached parameters for sensing all manner of environmental conditions, and component operating conditions, additional sensor inputs may be provided to the automated advanced hot water reset implementing device 170 to increase granularity of the output signal, and to thereby increase efficiencies realized by expanded implementation of the disclosed schemes. Also, the hot water reset implementing device 170 may actually be separately configured to calculate the monetary savings over linear reset and to calculate a payback to the user as an additional internal function. The hot water reset implementing device 170 may create and display an electronic interface in a form of, for example, an energy dashboard by which the energy used by the boiler and pumps may be displayed to the user.
A building Heating, Ventilation, and Air Conditioning (HVAC) system, including boiler and hot water circulating components such as those shown in FIG. 1, may be thermostatically controlled and include thermostats, valves, coils, air flow meters, temperature sensors, water flow meters and the like. The temperature required in the thermostatically controlled environments within a particular building may conventionally be considered a function of outside air temperature, solar load, heat dissipation factors and internal heat gains, such as, for example, from occupants, electronics, lighting and other heat producing bodies within the building.
The disclosed automated advanced hot water reset implementing device 170 may account for many of the above-enumerated conventionally-measured variables in optimizing the hot water system temperature that is delivered to the building. The disclosed systems and methods may ensure that the water is not too hot, thus wasting energy in a significantly inefficient manner, while providing for comparatively increased comfort to the occupants. The water supplied to the system may be employed by the exemplary HVAC system for providing optimal comfort within the building. The disclosed systems and methods may have the added advantage of “learning” building characteristic control profiles over time resulting in additional system control efficiencies.
FIG. 2 illustrates a block diagram of an automated advanced hot water reset implementing system 200 according to this disclosure.
As shown in FIG. 2, the exemplary system 200 may include an operating interface 210 by which a user may communicate with the system. The operating interface 210 may provide a user an opportunity to initiate and/or monitor the operation of the exemplary system 200, and to perform certain administrative functions with respect to the operation of the system, and potentially the extraction of data from the system. Additionally, the operating interface 210 may provide the user a capability by which to input any parameters appropriate to operation of the system including, but not limited to, initial building operating parameters, or boiler system operating parameters, for example, as may be received from the boiler manufacturer.
The operating interface 210 may be configured as one or more conventional mechanisms common to computing and/or communication devices that may permit the user to input information to the exemplary system. The operating interface 210 may include, for example, a conventional keyboard, a touchscreen with “soft” buttons or with various components for use with a compatible stylus, a microphone by which the user may provide oral commands to the exemplary system to be “translated” by a voice recognition program, or other like device by which a user may communicate specific operating instructions to the exemplary system 200.
The exemplary system 200 may include one or more local processors 220 for individually operating the exemplary system 200, and for carrying into effect the disclosed schemes for boiler control. The processor(s) 220 may carry out routines appropriate to operation of the exemplary system 200, and may undertake data manipulation and analysis functions appropriate to the interface established between the multiple sensor inputs and an output signal generated based on those inputs for boiler supply water temperature control.
Processor(s) 220 may include at least one conventional processor or microprocessor that interprets and executes instructions to direct specific functioning of the exemplary system 200, and control of the automated implementations of the boiler supply water temperature control techniques, methods or schemes according to this disclosure.
The exemplary system 200 may include one or more data storage devices 230. Such data storage device(s) 230 may be used to store data or operating programs to be used by the exemplary system 200, and specifically the processor(s) 220, in carrying into effect the disclosed boiler supply water temperature control techniques, methods or schemes. At least one of the data storage device(s) 230 may be used to store various sets of operating parameters and resultant determined boiler supply water temperature set points. These stored setpoints may be used for reference, or aggregated over time in order that the exemplary system 200 “learns” the characteristics of the building and the response of the building and the boiler controlled hot water circulating supply system to ranges of operating parameters exhibited by, and within, the building.
The data storage device(s) 230 may include a random access memory (RAM) or another type of dynamic storage device that is capable of storing updatable database information, and for separately storing instructions for execution of the exemplary system 200 operations by, for example, processor(s) 220. Data storage device(s) 230 may also include a read-only memory (ROM), which may include a conventional ROM device or another type of static storage device that stores static information and instructions for processor(s) 220. Further, the data storage device(s) 230 may be integral to the exemplary system 200, or may be provided external to, and in wired or wireless communication with, the exemplary system 200, including as cloud-based (or other virtual) data storage components.
The exemplary system 200 may include at least one data output or display device 240, which may be configured as one or more conventional mechanisms that output information to a user. The display device 240 may be used as a monitor to indicate to the user information regarding a compilation of individual sensor parameters as inputs from the individual sensors. It is not necessary that the user monitor the actual conduct of the operation by the exemplary system 200, but the user is afforded that option. The display device 240 may be any conventional data display device typically associated with computing and/or communications systems, including any one of myriad electronic data display devices.
The exemplary system 200 may include one or more separate input sensor signal interfaces 250 by which the exemplary system 200 may receive input from the myriad sensors outlined above in a manner that facilitates execution of its function of determining from those sensor inputs a particular boiler supply water temperature set point. Individual ones of the one or more separate input sensor signal interfaces 250 may include a translation and/or weighting capability such that the input signals from various types of sensors are made compatible with one another and given appropriate weight. In this manner, signals from various sensors may be “tuned” by the input sensor signal interfaces 250 to be compatible with one another for use in the exemplary system 200.
The exemplary system 200 may include an algorithm application device (which may be alternatively referred to as an application administration module) 260 that may be used to apply and administer the disclosed scheme that amalgamate the various sensor inputs according to the input sensor signals and produces a particular output signal to drive the boiler directly, or via a boiler management system or a boiler control panel to indicate by which that exemplary system 200 may communicate with multiple boilers which are often controlled by a master controller, or via an advanced digital building automation system, the firing (or heating) scheme of the boiler to efficiently achieve a particular determined boiler water supply temperature set point based on the conditions measured by the various sensor inputs. The algorithm application device 260 may be a component or capability of one or more of the processors 220, or may be made available as a standalone capability/component of the exemplary system 200.
The exemplary system 200 may include a separate signal generation device 270 which may be usable to take a result of the data manipulation undertaken by the algorithm application device 260 and convert a result of that sensor signal manipulation to a compatible signal for firing (or otherwise heating) the boiler to efficiently achieve the particular determined boiler water supply temperature set point. The signal generation device 270 may then communicate directly with the boiler, may otherwise communicate with the boiler through the advanced digital building automation system, or may separately communicate with the boiler via some intervening output signal interface 280 as may be required to condition the output signal for receipt by the particular components associated with the boiler for controlling inlet water temperature to the boiler. Each of the specific capabilities of the signal generation device 270 and the output signal interface 280 may be provided as a standalone system, or may be incorporated as a component or capability of one or more of the processors 220.
Each of the individual functions, modules, devices and/or units of the exemplary system 200 may be varyingly interconnected by one or more data exchange and control buses 290. Such data exchange and control buses 290 may take the form of one or more wired or wireless communications interfaces between the various enumerated components of the exemplary system 200. As indicated above for the data storage device(s) 230, the various components of the exemplary system 200 may be housed substantially together as an integral package, or may, in varying combinations, be housed individually as separate system components in wired, or wireless, communication with each other to effect the disclosed boiler supply water temperature control techniques, methods or schemes. In other words, all of the various components of the exemplary system 200, as depicted in FIG. 2, may be connected internally, and to one or more external components by one or more data/control busses 290. These data/control busses 290 may provide wired or wireless communication between the various components of the exemplary system 200, whether all of the components of the exemplary system 200 are housed integrally in, or are otherwise external and connected to, the exemplary system 200.
It should be appreciated further that, although depicted in FIG. 2 as an essentially integral unit, the various disclosed elements of the exemplary system 200 may be arranged in any combination of sub-systems as individual components or combinations of components, integral to a single unit, or external to, and in wired or wireless communication with the single unit of the exemplary system 200. Wireless communications may be by RF radio devices, optical interfaces, NFC devices and other wireless communicating means according to RF, Wi-Fi, WiGig and other like communications protocols. In other words, no specific configuration as an integral unit, or as a support unit, is to be implied by the depiction in FIG. 2. Further, although depicted as individual units for ease of understanding of the details provided in this disclosure regarding the exemplary system 200, it should be understood that the described functions of any of the individually-depicted components may be undertaken, for example, by one or more processors 220 connected to, and in communication with, one or more data storage devices 230, and the myriad sensors by which particular signal inputs are introduced into the exemplary system 200.
FIG. 3 illustrates a flowchart of an exemplary method for implementing an automated, and potentially artificially intelligent, scheme for implementing an advanced and efficient boiler control scheme according to this disclosure. As shown in FIG. 3, operation of the method commences at Step S300 and proceeds to Step S310.
In Step S310, multiple input sensors may be provided throughout a boiler-based hot water circulating environmental control system such as that shown, for example, in FIG. 1. The sensors may include, but not be limited to: an outlet (supply) water temperature sensor; and inlet (return) water temperature sensor; a pump speed sensor, a heated fluid flow rate sensor, a heated fluid loop pressure sensor, and an outside ambient air temperature sensor. Operation of the method proceeds to Step S320.
In Step S320, the automated advanced hot water reset device may be electrically activated. Operation of the method proceeds to Step S330.
In Step S330, the hot water system to be controlled by the advanced hot water reset device may be started by, for example, energizing the hot water pump. It should be noted that, once the hot water pump has proofed on, the hot water set point optimization calculations may begin according to the detailed steps of the method set forth below, and a targeted heating hot water supply set point may be generated and sent to the boiler management system or building automation system. Operation of the method proceeds to Step S340.
In Step S340, an initial hot water system supply water temperature set point may be established based on, for example, a traditional outside air temperature reset schedule, which may be combined (as appropriate) with a previous equivalent optimized set point as determined by the automated advanced hot water reset device. It should be further noted that, once the system has stabilized to the particular load conditions within the building (in, for example, approximately one hour) optimized system calculations may begin to adjust the traditional outside air temperature reset schedule to increase the heating system's efficiency based on inputs from others of the myriad sensors enumerated above. Operation of the method proceeds to Step S350.
In Step S350, the activated automated advanced hot water reset device may establish communications with the multiple input sensors. Operation of the method proceeds to Step S360.
In Step S360, signal inputs may be received by the automated advanced hot water reset device from multiple input sensors. The various signals may be translated, modified, and/or weighted by the automated advanced hot water reset device in order to be compatible with one another, and conditioned for use by the automated advanced hot water reset device. Operation of the method proceeds to Step S370.
In Step S370, signal inputs from the outlet (supply) water temperature sensor and the inlet (return) water temperature sensor may be compared to calculate a difference between water temperatures at these particular points in the controlled system. The calculated temperature difference between the outlet (supply) water temperature sensor and the inlet (return) water temperature sensor may be referred to as the hot water system's “Delta T” or “ΔT.” Delta T may be considered a best direct reflection of the heating load within the building. Operation of the method proceeds to Step S380.
In Step S380, in addition to the hot water system's Delta T, the hot water system pump speed, hot water flow, and/or hot water loop differential pressure may be monitored and may be further usable to optimize the hot water system's set point as specified by the operation of the automated advanced hot water reset device. Operation of the method proceeds to Step S390
In Step S390, each of the Delta T, the monitored one or more of the pump speed, the hot water flow rate and the hot water loop pressure, and the outside ambient air temperature may be manipulated by the automated advanced hot water reset device according to application of weighting factors, and/or implementing a particular hot water system set point control scheme to effect maximum efficiency specific to the particular building in which the monitored system is installed. Operation of the method proceeds to Step S400.
In Step S400, an actuation signal indicative of the hot water set point ultimately determined by the automated advanced hot water reset device may be generated according to the multiple sensor inputs and translated to one or more of a firing (or heating) schedule for the burner or boiler heating element, to adjust pump speed, to adjust loop pressure or to adjust any other physical parameter within the boiler system to increase efficiency of the boiler system. Operation of the method proceeds to Step S410.
In Step S410, determined optimal hot water system set points may be stored as a function, for example, of measured outside ambient air temperatures. Operation of the method proceeds to Step S420.
In Step S420, the stored value suboptimal hot water system set points as a function, for example, of outside ambient air temperatures may be used to compile a system/building specific optimal (non-linear) hot water reset schedule. Operation of the method proceeds to Step S430, where operation of the method ceases.
Purely by way of example, a targeted Delta T may be in a range of 15° F. to 25° F. depending on the performance of a building's HVAC system and the integrity of the building shell, among other environmental and operating factors. During such an exemplary condition, with a water pump speed between adjustable minimum and maximum speed setpoints of 40% and 75%, the calculated set point may remain unchanged. Conversely, when the Delta T is greater than the maximum set point value, and hot water pump speed is greater than the adjustable maximum speed setpoint of 75%, the optimization process may request a hot water set point increase of, for example, 5° F. Again by contrast, when the Delta T is less than the minimum value, and the hot water pump speed is less than the adjustable minimum speed setpoint of 40%, the optimization process may request the hot water set point decrease of 5° F. In any and all instances, the automated advanced hot water reset device may introduce time delays of, for example, at least 30 minutes, between varying setpoint adjustments in order to allow the system to stabilize to new adjusted set point levels.
The details of the method provided above should not be considered to imply that all of the method steps indicated must be accomplished, or accomplished in the order shown. No specific order to the disclosed method steps is implied by the depiction in FIG. 3, except insofar as execution of any particular one or more of the depicted method steps provides a necessary precursor to the execution of others of the depicted method steps.
The above-indicated sequence of operations may be programmed onto a controlling device. The language used for programming the controller may be proprietary to the manufacturer of the controller. Such proprietary programming language may not, however, adversely affect the implementation of the control methodology disclosed above.
The disclosed embodiments may include a non-transitory computer-readable medium storing instructions which, when executed by a processor, may cause the processor to execute all, or at least some, of the steps of the method outlined above.
Variations on the disclosed methods may include one in which the automated advanced hot water reset device may enable the hot water system whenever the ambient air temperature is below an enable setpoint of, for example, 60° F. In such instances, whenever the hot water system's calculated Delta T may be less than a minimum set point of, for example, 2° F. for a period of 30 minutes, or an outside ambient air temperature rises above 65° F., the automated advanced hot water reset device may disable the hot water system.
Other variations of the disclosed methods may include variations in which the automated advanced hot water reset device may command separate pumps to be operated in a lead/lag configuration. In such instances, the designation of the “lead” pump may be rotated among multiple pumps in order to equalize run times for the various pumps over time. The function of the designated “lead” pump may be to run whenever the hot water system is enabled. This configuration may leave the lag pump in reserve to be commanded “on” in instances in which the designated lead pump may fail to proof on. In such circumstances, the automated advanced hot water reset device, may provide the mechanism for designating the “lead” pump, for receiving a signal of the lead pump's failure to proof on, for sending a signal, in such circumstances, to command the lag pump on, and for enunciating a local alarm on a face of a control panel indicating variation in a planned scheme for which pump, among a plurality of pumps, may have failed to react in accordance with the planned scheme.
Other variations of the disclosed methods may include a variation in which the automated advanced hot water reset device may control the lead pump, once commanded on, such that its drive mechanism (to include, for example, a variable frequency drive or VFD) is commanded to a predetermined minimum speed setpoint. In embodiments, once the pump is proofed on, the VFD speed may be modulated to maintain a hot water loop differential pressure or Delta T at a particular set point rather than a speed of the pump at a particular level. In instances in which the hot water loop differential pressure decreases below the particular set point, a separate hot water loop bypass valve may be, for example, modulated closed to account for the pressure decrease before the VFD speed is increased. In such instances, if the hot water loop differential pressure remains below the setpoint, the automated advanced hot water reset device may then command VFD speed to be increased. Conversely, in instances in which the automated advanced hot water reset device has commanded the VFD speed to its minimum, and the hot water loop differential pressure may exceed its set point, the hot water bypass valve may be, for example, modulated open to relieve the pressure in a manner so as to maintain the hot water loop differential pressure set point without commanding a change in VFD speed.
Variations of the disclosed systems may include a variation in which multiple boilers may be controlled in individual buildings. The multiple boilers may operate in a lead/lag configuration. Variations may separately control multiple boilers in multiple buildings from a single remote location.
In instances in which embodiments of the disclosed systems “know” boiler efficiency curves at different firing rates, variations of the disclosed schemes may adjust the pump speed and boiler firing rate to optimize the energy efficiency of the entire hot water plant to allow the entire hot water plant to operate at its most efficient.
As condensing boilers entered the marketplace and provided new and more efficient technology, the dated linear reset control model remained the same. Linear reset has been used to control boiler supply temperature for decades. Given the capabilities of modern control methods, shortfalls and application of the linear reset model are overcome by implementation of the disclosed schemes as stand-alone control schemes or as part of broader building automation system methodologies. In this manner, the disclosed schemes may implement an invented new strategy to improve upon the linear reset curve and make possible even more efficient methods of continual reset.
Specific reference to, for example, the above-discussed embodiments for implementing advanced energy efficient boiler controls through, for example, an advanced digital building automation system, should not be interpreted to constrain the disclosed systems, methods, techniques, schemes, processes, products or product components to only those embodiments. The depicted and described embodiments are included for non-limiting illustration of the disclosed concepts for implementing these systems, methods, techniques, processes and schemes for more efficient building environmental controls may include, but are not limited to, use of the depicted component systems, as shown. All of the above depictions and/or descriptions should, therefore, be interpreted as being exemplary only, and not limiting the disclosed schemes, in any manner.
Features and advantages of the disclosed embodiments are set forth in this disclosure and may be, at least in part, obvious from this detailed description, or may be learned by practice of the disclosed embodiments. The features and advantages of the disclosed embodiments may be realized and obtained by means of the instruments and combinations of features particularly described.
Various embodiments of the disclosed systems and methods are discussed in this disclosure. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and scope of the disclosed embodiments.

Claims

We claim:

1. A building heating system, comprising:

at least one boiler comprising one or more heating elements, the one or more heating elements being selectively energized to heat a fluid medium in the at least one boiler;

piping that is connected between an outlet side of the at least one boiler and an inlet side of the at least one boiler, the piping being configured to circulate the heated fluid medium in the building;

at least one circulating pump that is configured to urge flow of the heated fluid medium through the piping;

a first sensor that is configured to generate a first input signal based on an ambient air temperature of an environment of the building;

at least one second sensor that is configured to generate at least one second input signal based on a sensed parameter measured by the at least one second sensor; and

a controller that is configured to receive the first input signal and the at least one second input signal and to generate at least one output signal for controlling at least one operating parameter of an operating component of the building heating system.

2. The building heating system of claim 1, the controller being configured generate the at least one output signal for controlling the at least one operating parameter of the operating component of the building heating system to modify a boiler supply water temperature set point.

3. The building heating system of claim 1, the at least one second sensor comprising one or more of: (1) an operation sensor associated with the at least one circulating pump; (2) a pump speed sensor; (3) an outlet or supply fluid temperature sensor; (4) an inlet or return water temperature sensor; (5) a piping loop pressure sensor; and (6 ) a heated fluid flow rate sensor.

4. The building heating system of claim 1, the at least one operating parameter being the selective energizing of the one or more heating elements of the at least one boiler as the operating component.

5. The building heating system of claim 1, the one or more heating elements being selected from a group consisting of combustible fuel fire heating elements, electrical heating elements, and heating elements powered by renewable energy sources.

6. The building heating system of claim 1, the at least one operating parameter being at least one of (1) selectively energizing, and (2) controlling an operating speed for, the at least one circulating pump as the operating component.

7. The building heating system of claim 6, the at least one circulating pump comprising a plurality of circulating pumps, and the at least one operating parameter being at least one of (1) selectively energizing, and (2) controlling an operating speed for, each of the plurality of circulating pumps in a specified order as the operating component.

8. The building heating system of claim 1, the piping including at least one selectable pressure relief valve and the at least one operating parameter being controlling a loop pressure in the piping by selectively opening and closing the at least one selectable pressure relief valve as the operating component.

9. The building heating system of claim 1, the at least one boiler being a condensing boiler.

10. The building heating system of claim 1, the at least one boiler being a plurality of boilers, each of the plurality of boiler being in communication with separate piping that is connected between an outlet side and an inlet side of the each of the plurality of boilers and at least one circulating pump that is configured to urge flow of the heated fluid medium from the each of the plurality of boilers through the separate piping,

the controller being configured to receive the first input signal and the at least one second input signal and to generate the at least one output signal for controlling the at least one operating parameter of the operating component of the building heating system associated with each of the plurality of boilers.

11. The building heating system of claim 1, the controller applying a selectable weighting factor to at least one of the first input signal and the at least one second input signal to generate the at least one output signal for controlling that at least one operating parameter of the building heating system.

12. The building heating system of claim 7, further comprising a user interface that is configured to allow a user to manually input the selectable weighting factor for the controller to apply to the at least one of the first input signal and the at least one second input signal to generate the at least one output signal.

13. The building heating system of claim 1, the at least one output signal for controlling the at least one operating parameter of the operating component being transmitted to the operating component from the controller via a digital building automation system.

14. The building heating system of claim 1, the controller being further configured to calculate and output a comparative analysis of an efficiency in operation of the building heating system as controlled by the controller with a baseline conventional linear reset model.

15. A method for heating a building heating, comprising:

providing at least one boiler comprising one or more heating elements, the one or more heating elements being selectively energized to heat a fluid medium in the at least one boiler;

providing piping that is connected between an outlet side of the at least one boiler and an inlet side of the at least one boiler, the piping being configured to circulate the heated fluid medium in the building;

providing at least one circulating pump that is configured to urge flow of the heated fluid medium through the piping;

providing a first sensor that is configured to generate a first input signal based on an ambient air temperature of an environment of the building;

providing at least one second sensor that is configured to generate at least one second input signal based on a sensed parameter measured by the at least one second sensor;

receiving, via a controller, the first input signal and the at least one second input signal; and

generating, with the controller, at least one output signal for controlling at least one operating parameter of an operating component of the building heating system.

16. The method of claim 15, the controller being configured generate the at least one output signal for controlling the at least one operating parameter of the operating component of the building heating system to modify a boiler supply water temperature set point.

17. The method of claim 15, the at least one second sensor comprising one or more of: (1) an operation sensor associated with the at least one circulating pump; (2) a pump speed sensor; (3) an outlet or supply fluid temperature sensor; (4) an inlet or return water temperature sensor; (5) a piping loop pressure sensor; and (6) a heated fluid flow rate sensor.

18. The method of claim 15, the at least one operating parameter being the selective energizing of the one or more heating elements of the at least one boiler as the operating component.

19. The method of claim 15, the at least one operating parameter being at least one of (1) selectively energizing, and (2) controlling an operating speed for, the at least one circulating pump as the operating component.

20. The method of claim 15, the piping including at least one selectable pressure relief valve and the at least one operating parameter being controlling a loop pressure in the piping by selectively opening and closing the at least one selectable pressure relief valve as the operating component.