TECHNICAL FIELD
The present disclosure relates to heating, ventilating, and air conditioning (HVAC) systems, and in an embodiment, but not by way of limitation, a cam actuated damper for HVAC systems.
BACKGROUND
In a Heating, Ventilating, and Air Conditioning (HVAC) system, cooling or heating air is a valuable resource that should be minimized in spaces that do not need much of it at a particular point in time, and should be delivered in greater volume to areas that require more of it at a particular point in time. Additionally, the space demands for cooling or heating air can be dynamic based on equipment load and/or the number of people occupying different locations at different times.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a bottom plate of a heating, ventilation, and air conditioning (HVAC) damper.
FIG. 2 is a plan view of a top plate of an HVAC damper.
FIG. 3 is a side view of damper.
FIG. 4 is an embodiment of a cam.
FIG. 4A is a side view of the cam of FIG. 4.
FIG. 5 is another embodiment of a cam.
FIG. 6 illustrates a damper in a closed position.
FIG. 7 illustrates a damper in a partially open position.
FIG. 8 illustrates a damper in an open position.
FIG. 9 is a diagram illustrating thermostatic control of a damper for an HVAC system.
FIG. 10 illustrates a control system for a damper for an HVAC system with a plurality of dampers.
FIG. 11 is an example of a control sensitivity map.
DETAILED DESCRIPTION
In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural and electrical changes may be made without departing from the scope of the present embodiments. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the present embodiments is defined by the appended claims.
A damper system is disclosed herein that senses demand for cooling and/or heating air, and adjusts the amount of cooling and/or heating air (measured by cubic feet per minute) provided to a particular room or area based on a dynamic profile. The damper system consequently conserves the cooling and/or heating air. The damper system may include a controller and damper assembly mounted in the raised access floor panels of a data center, a ceiling mounted diffuser, or a wall mounted diffuser. The mounting of the damper system to the floor panels, ceiling mounter diffuser, or wall mounted diffuser can employ any type of connector or connector system known to those of skill in the art such as rivets, screws, bolts, nuts, adhesives, and straps. The damper system may be configured as a single device with a localized controller or as a plurality of devices with a centralized controller.
More specifically, in an embodiment, a damper control system for a Heating, Ventilating, and Air Conditioning (HVAC) system includes a pair of plates with a pattern of openings, holes, or slots therein. In one example, the openings are rectangular. A cam is coupled to a top plate and operates to move the top plate relative to a bottom plate such that the openings in the top and bottom plates are more fully open, less fully open, fully open, or fully closed. In another embodiment, the damper control system could be configured such that the bottom plate moves in relation to the top plate. In another embodiment, for example when the damper system is coupled to a wall-mounted diffuser, a first plate is adjacent to a second plate. The cam includes a round or oval disk with an offset (i.e., off center) rotary drive hole. The cam is driven by a motor, and in a particular embodiment, a servo motor. The servo motor is controlled thermostatically, thereby further opening or further closing the alignment of the openings of the top and bottom plates based on the sensed temperature. The thermostatic control can be local to an individual damper and temperature sensor pair, or it can be networked to a central controller with a flexible sensor to damper control scheme via a sensitivity map.
FIG. 1 is a plan view of a bottom plate 100 of a heating, ventilation, and air conditioning (HVAC) damper assembly. The bottom plate 100 includes a frame 110 and openings, holes, or slots 120. FIG. 1 further illustrates a cam 130. The cam includes an opening 135 that is offset from the center of the cam 130. The opening 135 is for receiving a drive shaft 313 of a motor 310 (See FIG. 3). FIG. 2 is a plan view of a top plate 200 of an HVAC damper assembly. The top plate 200 includes a frame 210 and openings, holes, or slots 220. The top plate 200 further includes a cam follower 230.
FIG. 3 is a side view of a damper assembly. FIG. 3 illustrates the bottom plate 100, the top plate 200, the cam 130, the motor 310 (which can be a servo motor), and the shaft 313 that couples the motor 310 to the cam 130.
FIGS. 4 and 5 illustrate embodiments of a cam design. FIG. 4 illustrates a round cam 130 with an opening 135 that is offset from the center of the cam 130. FIG. 5 illustrates an oval cam 130 with an opening 135 that is offset from the center of the cam 130. FIGS. 3 and 4A illustrate that the cam 130 can include flanges 138 that extend past the body of the cam. The embodiment of FIG. 5 can also be made with or without the flanges 138. As illustrated in FIG. 3, the flanges capture the top plate 200, which prevents the cam from disengaging from the top plate 200.
FIGS. 6, 7, and 8 illustrate operations of a damper assembly. As illustrated in FIGS. 6, 7, and 8, the cam 130 is set into a recess or cam follower 230 in the top plate 200. A portion of the cam follower 230 is rectangular to contact with the cam, such that when the cam is driven by the motor 310, the top plate 200 moves along path A-A. In another embodiment, the cam follower 230 can be any other shape that permits the motion of the cam to move the top plate 200 along path A-A. The rounded portion of the cam follower 230 permits insertion of the cam 130 into the cam follower 230 during assembly. In the embodiment with the flanges 138, the outer diameter of the cam 130 as defined by the flanges 138 is larger than the rectangular portion of the cam follower 230, but the main body of the cam 130 is slightly smaller than the width of the rectangular slot so that the cam 130 fits into the rectangular slot (See FIG. 3). The rectangular portion of the cam follower 230 permits the contact points between the cam 130 and the cam follower 230 to move along the length of the cam follower 230 in FIGS. 6, 7, and 8. For example, the cam can move from right to left in FIGS. 6, 7, and 8 as the cam 130 rotates. FIG. 6 illustrates the damper in a closed position. In the closed position, the bottom plate 100 is visible through the openings 220 of the top plate 200. If the temperature in a particular area changes such that more cooling or heating air is needed, a temperature sensor senses such a need, and transmits a signal to the servo motor 310. The servo motor 310 causes its shaft, which is connected to the opening 135 of the cam 130, to turn the cam 130. Since the opening 135 is offset from the center of the cam 130, the cam moves along the displacement path A-A. Since the cam is set in recess 230 of the top plate 200, the top plate 200 moves along the path A-A, thereby offsetting the openings of the bottom plate 100 and the top plate 200 and causing the damper to become partially open, as is illustrated in FIG. 7. Specifically, FIG. 7 illustrates that only a portion of the bottom plate 100 and a portion of the slot 120 are visible. If the temperature sensor senses that more cooling or heating air is required, the servo motor keeps turning the cam 130, and the damper becomes fully open as is illustrated in FIG. 8, wherein the entire slot 220 of the top plate 200 is visible.
FIG. 9 is a diagram illustrating thermostatic control of an HVAC system using a damper system such as illustrated in FIGS. 1-8. The variables taken into account in the control of the damper system include the temperature set point, a dead band range on both sides of the set point, and a time interval. At 910, the controller checks to see if the time interval has elapsed. The time interval is simply the interval at which the space temperature is checked, and could be 5, 10, or 15 minutes, or any other time period. Moreover, this time period could be different lengths for different times of the day (e.g., daytime working hours versus nighttime downtime hours). If block 910 determines that the time interval has not lapsed, the flow loops back to 910 for checking the time interval at a later time. If the time interval has lapsed, block 920 determines if the temperature of the room, space, or particular area is within the set point and the width of the dead band range. For example, if the dead band range is +/−3 degrees, the set point is 72 degrees, and the current temperature is 73 degrees, the temperature is within the set point and dead band range. If the temperature is within the set point plus the dead band range, the flow loops back to block 910. If the temperature is outside of the bounds of the dead band range, then the flow proceeds to block 930. At block 930, the flow of cooling or heating air is increased or decreased depending on whether the current temperature is above the dead band range or below the dead band range.
FIG. 10 illustrates a control system for an HVAC damper system. The control system includes a controller 1000, one or more temperature sensors 1010, and one or more dampers 1020. The system can be configured such that the temperature sensor 1 provides temperature data for the control of damper 1, that the temperature sensor 2 provides temperature data for the control of damper 2, etc. In another embodiment, the controller can be configured to receive temperature data from all of the temperature sensors 1010, and control the dampers based on an aggregation of the data from the temperature sensors. In one embodiment, this is accomplished with the use of a control sensitivity map. An example control sensitivity map is illustrated in FIG. 11. For example, as illustrated in FIG. 11, seventy percent of the control of Damper 1 can be attributed to temperature sensor 1, and thirty percent of the control of Damper 1 can be attributed to temperature sensor 2.
The Abstract is provided to comply with 37 C.F.R. §1.72(b) and will allow the reader to quickly ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
In the foregoing description of the embodiments, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting that the claimed embodiments have more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Description of the Embodiments, with each claim standing on its own as a separate example embodiment.
Patent Application
20150024673
