Abstract:
A system for heating water to improve safety and efficiency. The system may have normal operation measured in time. After a time of normal operation, a water temperature setpoint may be checked. If the setpoint is not at a certain level, normal operation may continue. If the setpoint is within the certain level, water temperature may be measured. If the water temperature is less than a desired level, one or more draws of water may be measured for a preset temperature drop. If the draws do not meet the temperature drop, a return to check the setpoint may be made. If the draws meet the temperature drop, the setpoint may be reduced and a time of normal operation may be measured to determine whether a burn cycle occurs within the time. If not, normal operation may continue; but if so, a return to check the setpoint may be made.

Description:
BACKGROUND 
       [0001]    The present disclosure pertains to systems designed to heat fluids and particularly to devices that pertain to the efficiency and safety of heating fluids. 
       SUMMARY 
       [0002]    The disclosure reveals a system for heating water in a controlled manner to improve safety and efficiency. The system may have a mode of normal operation measured in terms of time. After a certain amount of time of normal operation, a temperature setpoint of the system may be checked. If the setpoint is not at a certain level, then normal operation may continue. If the setpoint is at the certain level, then water temperature of the system may be measured. If the water temperature is less than a desired level, then one or more draws of water may be checked for a preset temperature drop. If the draws do not meet the temperature drop, then a return to the setpoint may be made with subsequent actions as described herein. If the draws meet the temperature drop, then the setpoint may be reduced and normal operation may be measured in terms of time to determine if a burn cycle occurs within a preset amount of time. If not, then normal operation may continue; but if so, a return to a setpoint check may be made along with the subsequent actions as noted. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0003]      FIG. 1  is a diagram of a water heater that incorporates the present system and approach for heating water; 
           [0004]      FIG. 2  is a diagram of an illustrative example of a controller for a water heater; 
           [0005]      FIG. 3  is a diagram of a general water heater flow chart; and 
           [0006]      FIG. 4  is a diagram of water temperature control of a water heater system to prevent generating temperatures of water beyond a certain temperature to improve safety and energy savings. 
       
    
    
     DESCRIPTION 
       [0007]    The present system and approach may incorporate one or more processors, computers, controllers, user interfaces, wireless and/or wire connections, and/or the like, in an implementation described and/or shown herein. 
         [0008]    This description may provide one or more illustrative and specific examples or ways of implementing the present system and approach. There may be numerous other examples or ways of implementing the system and approach. 
         [0009]    Residential and commercial water heaters may use a ten to fifteen degree differential to maintain tank temperature. The temperature control may work sufficiently to deliver hot water; however, after multiple draws, the water tank can begin to stratify, leading to a set point at 135 degrees Fahrenheit (F) producing a temperature near 150 degrees F. at the top of the tank for supply. The hot water is not necessarily safe or comfortable for the user and also may waste more energy by increasing the top of the tank&#39;s ambient differential. The present algorithm may limit the return to a setpoint only during excess demand cycles. The reduction in return to setpoint may still maintain sufficient hot water; however, the burner advance turnoff could protect the user from scalding and excess energy consumption. 
         [0010]    The burning algorithm may track the gas valve history for the prior four hours of operation. A counter may track the number of burner on and off and total burner on time of each recovery. In the condition of 2 or more burn cycles in one hour, the algorithm may go live and on the third reheat cycle, the return to setpoint may be limited from zero to ten degrees F., depending on a total prior draw load and total burn time tracked leading up to the 3rd draw with in that hour. The reduction in setpoint may allow the regeneration of heat without the overshoot of tank temperature at the top of the tank. The hot water tank algorithm&#39;s reduction in set point may stay live for up to four hours to allow the tank to equalize tank temp. At that point, the return to set point may occur and water temp may rise to the desired tank temp within two to three degrees F. 
         [0011]      FIG. 1  is a diagram of a water heater  30  that may incorporate the present system and approach for heating water. A water tank  32  may have an input supply pipe or drip tube  44  for receiving fresh water and an output pipe or tube  46  for drawing water, particularly heated water as needed. Tank  32  may have an inner surface  42  and an outer surface  52 . Around tank  32  may be an insulating layer  34  and an external shell  36 . In tank  32  may be a rust inhibiting layer  50 . Toward a bottom of tank  32  may be a drainage valve  48 . Water heater  30  and tank  32  may have a top surface  54 . At a bottom of heater  30  and tank  32  at a bottom surface  56  may be a heater  38  which can use electricity, gas or a combination to create heat for increasing a temperature of water in tank  32 . In the diagram of  FIG. 1 , a gas burner  58  may be used as an illustrative example of heater  38 . There may be a combustion chamber  63  that is supplied with a fuel such as gas in a tube  66 . Combustion chamber  63  may have an enclosure  59  and or exhaust pipe flue  66  that runs from chamber  63  through tank  32  and top surface  54  to an outside exhaust vent. 
         [0012]    An ignition source  40  such as a pilot light may be fed fuel from tube  66 . A valve  67  may be electrically opened and closed. Valve  67  may close if not kept warm by pilot  60 , particular in the event that the pilot  60  is extinguished and cannot light the burner in an event that an electric signal from a controller  40  is a command to open valve  67 . Also, if pilot  60  goes out, then a thermal valve (a component of valve  67 ) connected to pilot  60  closes if not kept warm by pilot  60 . The precautionary measures are for preventing a release of gas from a non-functioning burner  38  and pilot  60 . 
         [0013]    A sensor  64  may be connected to controller  40  to provide a temperature of water in tank  32  to controller  40 . Input signals  70 , sensor signals  84  and settings  86  may go to controller  40 . Control signals  82  may be provided by controller  40 . Controller  40  may also have controls and indicators for a user. Examples may be gauges, lights, setting selectors, and the like. A controller  40  may be of various versions of models that vary from simple to complex arrangements. Controller  40  may operate relative to a program or algorithm as indicated herein. 
         [0014]    A diagram in  FIG. 2  shows an illustrative example of controller  40 . Input signals  70  may go to a processing block  72  which may incorporate a processor  71  and memory  78  that are connected to each other. A connection line  84  may connect one or more sensors  64  to a sensor input buffer circuit  74 . Sensor signals may be provided by sensor input buffer circuit  74  to processor  71 . Settings  86 , such as those of temperature and time, and the like, may go to settings buffer circuit  80  and then on to processor  71 . Output control signals may proceed from processor  71  to along connection line  82  to one or more valve actuators, and other actuators or components, and the like. Indicator signals may proceed from processor  71  along a connection line  83  to various instruments such as displays, gauges, indicator lights, sound emanating devices, and the like. Temperature and other setpoints may be entered along connection line  86  to a settings buffer circuit  80 . From circuit  80 , setting signals may go to processor  71 . Entries from inputs may be from thermostats, keyboards, tunable knobs, switches, and so forth. 
         [0015]      FIG. 3  is a diagram of a general water heater flow chart. Symbols may represent blocks, steps, statuses, activity or other items, even though they might be referred to as “symbols” for purposes of the diagram. Symbol  91  may indicate that a water temperature control system is in standby. A question of whether water temperature is less that a setpoint minus tolerance may be asked at symbol  92 . If an answer is no, then there may be a return to standby. If the answer is yes, then a heating cycle (burn cycle) may occur at symbol  93 . At symbol  94 , a question of whether the water temperature is greater than the setpoint plus tolerance may be asked. If an answer is no, then the heating cycle may occur. If the answer is yes, then a return to standby may be made. 
         [0016]      FIG. 4  is a diagram of water temperature control that may prevent a water heater system from generating temperatures of water beyond a certain temperature to improve safety and energy savings. Symbol  11  may represent normal operation of a water heater. A timer may be started at symbol  12 . A question at symbol  13  may ask whether the timer has run for more than one hour. If an answer is no, then a return may be made to symbol  11  and symbol  12 . The question at symbol  13  may be asked again. If the answer is yes, then a question at symbol  14  may be asked as to whether a set point of the water heater is greater than 125 degrees Fahrenheit (F) or less than 150 degrees F. If an answer is no, then a return may be made to symbol  11  of normal operation. If the answer is yes, then a question at symbol  15  may be asked as to whether a water temperature in the water heater is less than C*(88 degrees F.). If the answer is yes, then a return to normal operation at symbol  11  may occur. If the answer is no, then at symbol  16  a question asked may be whether two draws within X minutes (60&lt;X&lt;75) with a temperature drop greater than D*(˜25 degrees F.) in M (˜10) minutes on each draw. If an answer is no, then a return to symbol  14  may be made with sequences to follow symbol  14  as indicated herein. If the answer is yes, then the set point may be reduced by Y*(˜5 to 10 degrees F.) at symbol  17 . Subsequently, a timer may be started and normal operation can occur at symbol  18 . A question may then be asked at symbol  19  as to whether a burn cycle is within four hours. If an answer is no, then a return to normal operation at symbol  11  may occur. If the answer is yes, then a return may be made to symbol  14  with sequences of operation to follow as indicated herein. 
         [0017]    To recap, a water heater control mechanism may incorporate a processor having a memory, a temperature sensor situated in a tank of a water heater and connected to the processor, a heater connected to a valve or switch, a setpoint device connected to the processor, an actuator attached to the valve and connected to the processor, and a program situated in the memory. The processor may have a normal operation for controlling temperature of water in the tank relative to a setpoint for temperature of the water. The program may provide steps that incorporate timing a length of normal operation, reading the setpoint device if the timing of a length of the normal operation exceeds a pre-determined time, reading the temperature sensor if a reading of the setpoint device is between two pre-determined temperatures, measuring one or more draws in terms of time and temperature if the reading of the temperature sensor is equal to or greater than a pre-determined temperature, reducing a setting of the setpoint device if the terms of time and temperature are within pre-defined terms of time and temperature for a draw, timing to when a burn cycle occurs, and reading the setpoint device if a time until a burn cycle occurs is greater than a pre-determined time. 
         [0018]    If the reading of the setpoint device is not between the two pre-determined temperatures, then the processor may return to normal operation. 
         [0019]    A return to reading the setpoint device may occur if the terms of time temperature for a draw are not within the pre-defined terms of time and temperature for a draw. 
         [0020]    If the timing of the length of the normal operation does not exceed the pre-determined time, then the processor may continue in normal operation. 
         [0021]    The two pre-determined temperatures for the setpoint device may be between A degrees Fahrenheit and B degrees Fahrenheit. 
         [0022]    If the reading of the temperature sensor is equal to or less than the pre-determined temperature, then the processor may return to normal operation. 
         [0023]    The pre-determined temperature for the temperature sensor may be C degrees Fahrenheit. 
         [0024]    The pre-defined terms of time and temperature may incorporate J draws or K pair or pairs of draws with a period between D minutes and E minutes with a temperature drop of F degrees Fahrenheit in G minutes on each draw. 
         [0025]    A return of the processor to normal operation may occur if the time until the burn cycle occurs is equal to or less than the pre-determined time. 
         [0026]    The pre-determined time for when the burn cycle occurs may be H hours. 
         [0027]    Illustrative example numbers for the variables may be A˜125, B˜150, C˜80, D˜60, E˜75, F˜25, G˜10, H˜4, J˜2 and K˜1. 
         [0028]    A fluid heater system may incorporate a tank, a heater at the tank, a fluid input on the tank, a fluid output on the tank, a heater control device connected to the heater, a temperature sensor situated in the tank, a temperature setpoint mechanism, a timer, and a processor connected to the heater control device, the temperature sensor, the temperature setpoint mechanism and the timer. The processor may control the heater control device, adjust the temperature setpoint mechanism and operate a timer in response to the temperature sensor, according to a program. 
         [0029]    A maximum temperature of a fluid in the tank may be controlled by the processor and heater control device according to the program. 
         [0030]    A setpoint on temperature setpoint mechanism may result in a temperature of a fluid in the tank greater than a temperature indicated by the setpoint due to temperature stratification of the fluid in the tank. The program may limit a return to a setpoint just during excess demand cycles, to reduce the temperature of the fluid in the tank increased by temperature stratification. 
         [0031]    The heater may be a gas burner. The heater control device may incorporate a valve connected to the gas burner, and an actuator that controls the valve and is connected to the processor. The program may track a history of the valve that reveals a number of times that a burner turns on and off and the total on-time of the burner. After a sequence of a pre-determined number of times that the burner turns on and off, the program may limit a return to the setpoint by a certain number of degrees less than the setpoint of the temperature setpoint mechanism according to the total on-time of the burner and amount of fluid draw from the tank within a given period of time. 
         [0032]    The heater may be electric. 
         [0033]    Steps of the program may incorporate 1) measuring a time of a normal operation of the processor, 2) checking a setpoint of the temperature setpoint mechanism if a time of the normal operation exceeds an A hour duration, 3) detecting a temperature less than B degrees Fahrenheit of the fluid if the setpoint of the temperature setpoint mechanism is between C degrees and D degrees Fahrenheit to take the processor out of normal operation, 4) making E draws of fluid from the tank within an F minute duration between a G minute duration and an H minute duration with a temperature drop detected by the temperature sensor greater than I degrees Fahrenheit of a J minute duration on each draw occurring that results in reducing the setpoint by K degrees between L degrees and M degrees, or in absence of each draw occurring as such results in going to step 3), 5) measuring a time of another normal operation of the processor, and 6) determining that an electric heat cycle has occurred within an N hour duration and thus resulting in returning to step iii), or determining that an electric heat cycle has not occurred thus resulting in the processor remaining in normal operation. 
         [0034]    A, B, C, D, E, F, G, H, I, J, K, L, M, and N may be numbers associated with units as fitting in their context. 
         [0035]    One or more items may be selected from a group incorporating A being about 1, B being about 80, C being about 125, D being about 150, E being about 2, F being between G and H, G being about 60, H being about 75, I being about 25, J being about 10, K being between L and M, L being about 5, M being about 10, and N being about 4. 
         [0036]    One or more items may be selected from a group comprising A is between 0.05 and 5, B is between 40 and 120, C is 80, D is 200, E is between 1 and 10, F is between G and H, G is 5, H is 250, I is between 5 and 125, J is between 1 and 60, K is between L and M, L is 0, M is 50, and N is between 0.1 and 10. 
         [0037]    A water heater may incorporate a tank, a water heater attached to the tank, a control device connected to the water heater, a temperature sensor in the tank, a temperature setpoint mechanism, and a controller connected to the control device, temperature sensor and a temperature setpoint mechanism. The processor may operate according to a program that causes normal operation of the heater to be overridden by an occasional setpoint adjustment to ensure efficiency and a supply safe hot water temperature. 
         [0038]    The program may incorporate occasionally checking the setpoint of the temperature setpoint mechanism, continuing normal operation if the setpoint is at an acceptable setting, obtaining a temperature of water in the tank from the temperature sensor if the setpoint is absent from a predetermined setting, returning to normal operation if the temperature of the water is at predetermined magnitude, obtaining a temperature drop evaluation of one or more draws of water if the temperature of the water is absent from a predetermined magnitude, rechecking the setpoint if the temperature drop evaluation is high, reducing the setpoint if the temperature drop evaluation is low, starting timing normal operation of the heater to detect whether a burn cycle occurs within a predetermined period of time, rechecking the setpoint if the burn cycle occurs, and continuing normal operation if a burn cycle does not occur. 
         [0039]    U.S. patent application Ser. No. 14/225,308, filed on Mar. 25, 2014, is hereby incorporated by reference. 
         [0040]    Any publication or patent document noted herein is hereby incorporated by reference to the same extent as if each individual publication or patent document was specifically and individually indicated to be incorporated by reference. 
         [0041]    In the present specification, some of the matter may be of a hypothetical or prophetic nature although stated in another manner or tense. 
         [0042]    Although the present system and/or approach has been described with respect to at least one illustrative example, many variations and modifications will become apparent to those skilled in the art upon reading the specification. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the related art to include all such variations and modifications.