1. Field
A steam distribution control system and method for a steam heating system are disclosed herein.
2. Background
Steam heating systems are known. However, they suffer from various disadvantages.
Embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein:
Embodiments of a steam distribution control system and method for a steam heating system are described in detail with reference to the accompanying drawings. Where possible, like reference numerals have been used to refer to like elements, and repetitive disclosure has been omitted.
Many older homes, apartment buildings, and commercial buildings may employ steam heating systems, for example, single-pipe steam heating systems. Such heating systems may employ gas or oil-fired boilers to supply steam to a plurality of radiators distributed throughout the building. One disadvantage of such systems is uneven heat distribution. An apartment building, for example, may have the heat adjusted according to needs of a coldest unit (for example, a unit that is most difficult to heat) causing other units to be over-heated. Tenants in the over-heated units may open windows to compensate. This is a costly and grossly inefficient means of heat balancing. The unfortunate results are a significant waste of fuel, increased pollution, and compromised comfort of the building inhabitants.
A complete replacement of a building's steam-heat system is typically cost prohibitive. Less dramatic remedies exist, but these are marginally effective and difficult to install and adjust.
In a single-pipe steam heating system, a boiler may heat water into steam under the control of a single thermostat. The steam may rise up through a plurality of pipes to a plurality of radiators. After the steam transfers its heat through a radiator into a room, the steam may condense back into water and drip down the same pipe, through which it rose, back to the boiler.
Each radiator may have a steam-air vent or steam inlet valve on one end, and a steam-air outlet valve on the other end. The steam-air vent may be, for example, a small hole in the radiator. The distribution of steam, and thus heat, may be determined by relative sizes of the steam-air vent holes. If a radiator has a large steam-air vent hole, more steam will enter that radiator than will enter a radiator having a smaller vent hole. The process of adjusting the sizes of the individual vent holes is called balancing. This is, for a vast majority of steam heating systems, a manual process based on intuition and rule of thumb.
The steam distribution control system and method for a steam heating system according to embodiments disclosed herein may provide, for example, the following features: automatic and dynamic radiator balancing; distributed temperature sensing; system-level intelligent and adaptive control; data logging for offline energy efficiency and operation analysis; remote, real-time status monitoring and control; real-time fault notification via the Internet or telephone.
The steam distribution control system according to embodiments disclosed herein may include a central controller, a plurality of distributed temperature sensors, and a novel steam-air vent for each radiator. The steam distribution control system according to embodiments disclosed herein may also include one or more thermostats. The central controller may monitor the plurality of temperature sensors and/or one or more thermostats, and intelligently control the boiler and each radiator's steam-air vent. The central controller may maintain comfortable heat levels based on user desired temperature settings or schedules and optimize the boiler's energy usage. Further, the central controller may recognize and alert users to excessive heat-use situations, such as those caused by open windows and propped doors.
The steam distribution control system according to embodiments disclosed herein may further include a boiler switch for the boiler. The central controller may intelligently control the boiler switch.
Further, the one or more thermostats are optional. When omitted, user interface may be provided solely by or at the central controller.
Communication between the central controller and the individual components may be via, for example, a low-power, wireless mesh network, such as, for example, ZigBee or Z-Wave. This type of network requires little electrical power, and thus, facilitates battery powered operation of the various devices of the system. The central controller may include connection(s) to telephone, Internet, and/or Bluetooth.
The plurality of steam-air vents, the plurality of temperature sensors, and/or the one or more thermostats may be battery powered, and may communicate wirelessly with the central controller via the wireless mesh network. The only wiring required by the steam distribution control system may be that between the boiler and boiler switch.
Software items for the system may include, for example, controller software, bluetooth cellular phone software (optional), and desktop software.
The steam distribution control system 10 of
The central controller may wirelessly communicate with the plurality of steam-air vents 42, the plurality of indoor temperature sensors 52, the one or more outdoor temperature sensor(s) 54, the one or more thermostat(s) 50, and/or the boiler switch 22. That is, a wireless mesh network, such as ZigBee or Z-wave, may be provided for communication between the central controller 60 and the plurality of steam-air vents 42, the plurality of indoor temperature sensors 52, the one or more outdoor temperature sensor(s) 54, and/or the one or more thermostat(s) 50.
The central controller 60 may be configured to selectively control the plurality of steam-air vents 42 to control an amount of steam distributed into each of the plurality of radiators. That is, the central controller 60 may be configured to control each of the steam-air vents 42 to control a flow of steam into each radiator 42. This may be accomplished by opening and closing the steam-air vent 42 to control the flow of steam into the radiator 42, or by controlling an opening amount of an orifice of the steam-air vent 42 to control the flow of steam into the radiator 40.
The steam distribution control system 10 may include the one or more thermostat(s) 50 distributed throughout the apartments 30, which may provide one or more user interface(s) with the steam distribution control system 10. Alternatively, a user interface may be provided solely at the central controller 60.
As shown in
Further, the central controller 60 may include an Internet interface device or component 68, which provides the central controller 60 with access to the Internet, a short range wireless device interface device or component 63, such as Bluetooth, which allows the central controller 60 to communicate with another device, such as a mobile phone, having such capability, and/or a memory card interface device or component 63, which allows the central controller 60 to communicate with a memory card, such as a secure digital (SD) card or USB memory stick, to upload data therefrom or download data thereto.
A backup central controller (not shown) may be provided in case of malfunction or failure of the central controller 60. Alternatively, the system may be configured so that the steam heating system reverts back to pre-existing control means in the case of malfunction or failure of the central controller.
As set forth above, the plurality of temperature sensors 30, the one or more thermostat(s) 50, and/or the plurality of steam-air vents 42 may communicate with the central controller 60 via a wireless mesh network. In such a case, the only required wiring may be that between the boiler 20 and the boiler switch 22.
The plurality of temperature sensors 30 provide the central controller 60 with sensed temperatures at various locations. Using the sensed temperatures provided by the plurality of temperature sensors 30, the central controller 60 may selectively control the plurality of steam-air vents 42 to control the distribution of steam to the plurality of radiators 40.
For example, the steam distribution control system 10 may divide a building into multiple, uniquely and/or individually controlled zones. A zone may be, for example, one room, many rooms, an entire apartment, an entire floor of the building, or another configuration.
Each zone may have one or more temperature sensors 52 and/or one or more thermostat(s) 50. Temperature sensors may be provided in un-controlled areas (for example, un-heated areas and outdoors), as well. For example, outdoor temperature sensor 54 may be provided. Coverage of the building with temperature sensors facilitates optimized control, efficiency, and fault detection.
A unique target temperature for each zone may be controlled by a respective temperature schedule. The temperature schedules may be managed by the central controller 60. The temperature schedules may be set through a remote desk-top application in communication with the central controller, a built-in webserver, or via the optional thermostats. With respect to this embodiment, it is noted that while a thermostat may be used to configure a temperature schedule, it may not directly control the boiler or a zone's steam-air vents. All of the control may be central to the central controller 60.
When one or more zones requires heat, the central controller 60 may turn on the boiler 20 via the boiler switch 22, starting a boiler cycle. Throughout the boiler cycle, the central controller 60 may uniquely manipulate each steam-air vent 42 to achieve a desired heating behavior. All of the steam-air vents 42 in a zone may be opened and closed or varied in unison, under the direction of the central controller 60. Alternatively, the steam-air vents 42 in a zone may be individually and selectively controlled by the central controller 60 to obtain the desired heating behavior.
The central controller 60 may characterize a thermodynamic behavior of the zones and/or of the building as a whole, and periodically adapt its algorithms to optimize operation. For example, a zone calling for heat, which is situated above another zone also calling for heat, may be shut off early, in expectation of the additional heat that will rise from the lower zone. Similarly, a zone whose temperature after a boiler cycle decreases a little or not at all (due to, for example, solar heat absorption) may have its steam reduced or removed completely for the next boiler cycle. The control algorithms may adapt to such contingencies using various means, one example being dynamic computation of unique heating coefficients for each zone. This parameter is basically a correlation of steam usage and heat rise over time, and may be dynamically re-computed to account for an outdoor temperature and temperatures of adjoining zones. The heating coefficients allow the steam distribution control system according to embodiments disclosed herein to predict a rate of heat rise of a zone in any situation, and thus, ensure that zones reach their target temperatures simultaneously, avoiding over-heating.
Thus, the central controller 60 may monitor the temperature sensors 52, the temperature sensor(s) 54, and/or the thermostats 50 and control the steam-air vents 42 and/or the boiler switch 22 to obtain the desired heating behavior for the one or more zones and/or the building as a whole. The central controller 60 may continuously monitor the heating profile(s) of the one or more zone(s) and/or the building as a whole, and compute updated solutions based on the sensed temperatures and desired temperature schedules for each of the one or more zones and/or the building as a whole.
Experiments conducted by the Inventors have shown that closing a vent on an already hot radiator may not significantly coot a radiator throughout a remainder of a boiler cycle. On the other hand, starting the boiler cycle with the vent closed may prevent steam from entering the radiator until the vent is opened.
Since a hot radiator may not be cooled during the boiler cycle, the steam distribution control system and method according to embodiments disclosed herein may instead delay heating of a radiator by delaying opening of the vent of the radiator. An amount of delay time applied to a zone's radiators may be a function of that zone's heating coefficient and temperature set point(s).
Steam heating systems, especially older ones, have reliability issues. The reliability issues may be caused, for example, by boiler burner clogs, water and steam leak, obscured radiators, and other occurrences that may compromise system operation. Misuse and tampering may also be problematic. Factors external to the steam heating system may adversely affect heating effectiveness and efficiency, as well, such as open windows and doors.
The central controller 60 may include configurable monitors that detect, for example, failures or misuse, and may issue a warning or alert. The resulting warning or alert may be transmitted as, for example, emails or text messages to a user or administrator, in addition to being stored in the memory device 64. Further, the warning or alert may include impending maintenance needs or instructions, a record of which may also be stored in the memory device 64.
The central controller 60 may dynamically compute a heating coefficient for each zone. Before every boiler cycle, the central controller 60 may predict a zone's heat rise according to its coefficient. Open windows may cause a deviation from the predicted behavior. The central controller 60 may detect the deviation and issue an alert.
An area need not be heated to have predictable behavior. For example, a zone need not have a radiator receiving steam to have predictable behavior, as it will receive heat from adjoining zones. Thus, a temperature sensor in an unheated area may be utilized to influence distribution of steam by the steam distribution control system and method according to embodiments disclosed herein. This may allow the steam distribution control system and method according to embodiments disclosed herein to detect, for example, a propped door in an unheated lobby or entry area.
All events may be logged and stored within the central controller 60, for example, in the memory device 64. This may include temperature data, alerts, the turning on and off of the boiler, the opening and closing or varying of the vent openings of the steam-air vents, and temperature set point changes. The log data may be transferred to a computer of, for example, a user or an administrator, such as a building's superintendent, for analysis by a desktop application as discussed herein below.
The desktop application may allow a user or administrator to remotely examine and analyze log data, adjust the steam distribution control system configuration and programming, and add components to extend the steam distribution control system. The desktop application may connect to the central controller 60 through various means, for example, a direct Internet connection, a memory card, or a short range wireless connection. A memory card, such as a SD card or USB memory stick, may be used to transfer data between the central controller 60 and a computer containing the desktop application. The central controller 60 may read new programming data from the memory card, and put data on the memory card that is destined for the desktop application.
The short range wireless connection may be, for example, a smartphone and Bluetooth wireless link, employed for data transfer. A smartphone application may be provided that includes some subset of the desktop application's features.
Each of the individual devices or components of the steam distribution control system according to embodiments disclosed herein may be battery powered where permissible. This results in a low power and/or low cost control system.
The steam-air vent 42 may be a type of steam-air vent that merely opens and closes a vent opening. With such a configuration, the central controller 60 would control the steam-air vent 42 to selectively open and close the steam-air vent to control an amount of steam that follows into the respective radiator 40. Alternatively, the steam-air vent 42 may be a type of steam-air vent that varies a vent opening amount to vary a flow rate of steam. With such a configuration, the central controller 60 would control a vent opening amount of the steam-air vent 42 to control a flow rate of steam into the respective radiator 40. In either case, the central controller 60 may selectively control the plurality of steam-air vent 42 to control an amount of steam distributed into each of the plurality of radiators 40.
An example of a type of steam-air vent that opens and closes a vent opening is shown in
As shown in
The exemplary steam-air vent of
The central controller 60 communicates with the microcontroller 110 via the wireless mesh network interface device 125 to control the steam-air vent 42, selectively opening and closing the vent opening 44 by activating and de-activating the solenoid 45.
An example of a type of steam-air vent that varies a vent opening amount is shown in
The steam-air vent 142 of
The first vent opening 144 is shown with respect to this embodiment in the shape of a slot; however, other shapes may also be appropriate. Further, the second vent opening 141c is shown with respect to this embodiment as triangular in shape; however, other shapes may also be appropriate.
The steam distribution control system according to embodiments disclosed above provides a high degree of control and allows management of an entire building. However, one of ordinary skill in the art will recognize that the steam distribution control system according to embodiments disclosed herein may be configured to address simpler applications.
That is, the steam distribution control system according to this embodiment may manage heating of only a single zone, for example, an apartment, and may not control the boiler. The steam distribution control system according to this embodiment may employ one or more steam-air vents 42 controlled by a combination thermostat-controller 150. The steam distribution control system of this embodiment is similar to a Thermostatic Radiator Valve (TRV), which is a steam-air vent that adjusts to its location's temperature.
A TRV senses a temperature just inches from a radiator to which it is attached or a few feet away using a wired temperature probe. Thus, a TRV cannot accurately determine a zone's heating requirement. The steam distribution control system according to this embodiment, on the other hand, may sense a temperature at the thermostat-controller 150 and/or temperature sensors 52. The thermostat-controller 150 may communicate with the steam-air vents 42 wirelessly.
The distributed temperature sensing of the embodiments disclosed herein may alleviate problems associated with a single, centrally located thermostat and/or a temperature sensor located immediately adjacent to a radiator. For example, the location of a single thermostat may not well represent the temperature of, for example, an entire apartment or building, as its location may become over or under-heated due to, for example, usage and/or weather conditions. Further, a malfunctioning or misused thermostat may upset the heating of the entire apartment or building.
Locating a thermostat in a central location implies that the location must be heated even if it is uninhabited. For example, a foyer of an apartment or a lobby of an apartment building is a common location for a thermostat. The foyer or lobby loses heat through entry doors, windows, and stairwells. Sensing temperatures within living areas instead allows the heat distributed to a central location to be reduced or completely removed, providing a significant energy savings.
The steam distribution control system 100 of
Similar to the embodiment of
Similar to the embodiment of
Under-sized radiators, radiators fed by undersized pipes, and radiators far from the boiler 20 often may not accept enough steam to adequately heat their area, even with a fully open steam-air vent. To compensate, users often increase the output of adjacent radiators, over-heating one space to satisfy another. A pump-equipped steam-air vent 342 may increase a radiator's affinity for steam by creating a partial vacuum that draws steam actively into the radiator. The central controller 360 of
The plurality of steam-air vents 342 may be driven by an electric motor (not shown). Thus, power may be drawn from AC mains, a rechargeable battery pack, or from energy scavenged from the radiator, for example, with a thermoelectric generator.
Similar to the embodiment of
The method of
The method of
The method of
The method of
The steam distribution control system for a steam heating system according to embodiments disclosed herein is easy to install.
To install the steam distribution control system according to embodiments disclosed herein, a wireless mesh network is first set up, in step S1310. Next, each component or device of the steam distribution control system is associated with the wireless mesh network, in step S1320. Then, one or more zone(s) are set up, in step S1330, and the various components or devices (not including the central controller) are assigned to the one or more zone(s), in step S1340. The components or devices are then installed in the respective zone(s), in step S1350. The steam heating system is then ready for activation and may receive input of desired temperature schedules for each zone(s).
Once the steam distribution control system according to embodiments disclosed herein has been installed, a site has a wireless mesh network. Other functions may then be piggy-backed over the network. Once such example is a wireless front door access system. This would not require a dedicated phone line to call a telephone linked to the apartment, the typical means used today. It would allow a voice intercom to the front door of the building. It would also allow the administrator to “broadcast” messages to all (or some) units in the building. Another is integrating wireless smoke detectors with the larger hard-wired fire system.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
This application is a Continuation-In-Part of U.S. patent application Ser. No. 12/512,491, filed Jul. 30, 2009, which claims priority to U.S. Provisional Application No. 61/085,040, filed Jul. 31, 2008. These applications are hereby incorporated by reference.
Number | Date | Country | |
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61085040 | Jul 2008 | US |
Number | Date | Country | |
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Parent | 12512491 | US | |
Child | 12544364 | US |