Modulation control of hydronic systems (thermodynamic process control) electricity and magnetism pdf

#

The present application is a continuation-in-part of U.S. application Ser. No. 11/949,314 entitled “Modulation Control of a Hydronic Heating System”, filed Dec. 3, 2007, which is a continuation-in-part of U.S. application Ser. No. 11/627,739, entitled “Hydronic Heating System”, filed Jan. 26, 2007 (collectively the “Priority Applications”). This present application claims priority and benefit of the Priority Applications to the extent the subject matter of this present application is found in the Priority Applications. The content of the Priority Applications is incorporated herein by reference. TECHNICAL FIELD

The present disclosure generally relates to modulation control of various hydronic systems utilizing one or more energy sources for a particular purposes, such as, for example, systems utilizing natural gas, oil, coal, gasoline, steam, water and/or electricity for purposes of providing heating, cooling, pumping, current output and/or mechanical energy. The present disclosure specifically relates to an energy based modulation control of such hydronic systems. BACKGROUND

Temperature based modulation control schemes of boilers as known in the art are generally premised on operating the boilers as temperature devices based on an error calculation between a set-point temperature and a supply temperature. More particularly, in response to the supply temperature being less than the set-point temperature, the temperature based modulation control scheme would ramp up the heating output of one or more of the boilers until the supply temperature equaled the set-point temperature. Conversely, in response to the supply temperature being greater than the set-point temperature, the temperature based modulation control scheme would ramp down the heating output of one or more of the boilers until the supply temperature equaled the set-point temperature.

While in practice the temperature based modulation control schemes may have involved various subcontrol features (e.g., a proportional—integral—derivative control feature of the ramping up/ramping down of boiler(s) or a timing control feature for enabling/disabling boiler(s), the operation of the boilers as temperature devices impede efficient operation of the boilers for various reasons, primarily the absence of a calculation of a real-time heating load also known herein as an energy load or system energy load. SUMMARY

One form of the present disclosure is an energy exchange system employing a hot water loop, a chilled water loop, an energy exchanger, a boiler plant for heating water flowing through the hot water loop and for heating water flowing through the chilled water loop via the energy exchanger, a chiller plant for chilling the water flowing through the chilled water loop and for chilling the water flowing through the hot water loop via the energy exchanger, and a control for calculating a hot energy load for operating the at least one boiler to heat the water flowing through the hot water loop and for heating the water flowing through the chilled water loop via the energy exchanger, and for calculating a chilled water energy load for operating the at least one chiller to chill the water flowing through the chilled water loop and for chilling the water flowing through the hot water loop via the energy exchanger.

The foregoing form and other forms of the present disclosure as well as various features and advantages of the present disclosure will become further apparent from the following detailed description of various embodiments of the present disclosure read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the present disclosure rather than limiting, the scope of the present disclosure being defined by the appended claims and equivalents thereof. BRIEF DESCRIPTION OF THE DRAWINGS