Advanced starting control for heating/cooling systems

• US 6,591,901 B2
• Filed: 08/06/2002
• Issued: 07/15/2003
• Est. Priority Date: 05/17/2000
• Status: Expired due to Term

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Bujak, Walter E. Jr.
• Primary Examiner(s): CIRIC, LJILJANA V
• Application Number:
  US10/212,387
• Publication Number:
  US 20020185271A1
• Time in Patent Office: 343 Days
• Field of Search: 165/205, 165/208, 165/209, 165/218, 165/219, 165/220, 165/221, 165/238, 165/239, 165/236, 165/200, 237/2.R, 237/2.B, 237/8.A, 237/12, 62/56, 621/32, 621/15, 621/766, 621/961, 621/97, 621/58, 621/73, 621/75, 364/148, 700/8, 700/17
• US Class Current: 165/209
• CPC Class Codes: F24F 11/54 using one central controller connected to several sub-controllers
• CPC Class Codes: F24F 11/83 by controlling the supply of heat-exchange fluids to heat-exchangers
• CPC Class Codes: F24F 11/84 using valves
• CPC Class Codes: F24F 2221/54 Heating and cooling, simultaneously or alternatively
• CPC Class Codes: F24F 3/06 characterised by the arrangements for the supply of heat-exchange fluid for the subsequent treatment of primary air in the room units
• CPC Class Codes: G05D 23/1934 each space being provided with one sensor acting on one or more control means

Abstract

A system and method for controlling delivery of either heated or cooled water to a plurality of heat exchangers includes a system controller which gathers information as to the current and future heating or cooling demands of a plurality of zone controllers associated with the plurality of heat exchangers. The system controller is operative to provide heated or cooled water to the heat exchangers even though current heating or cooling demands may not be sufficient to require the provision of heated or cooled water to the heat exchangers. The system controller analyzes current demands for heating or cooling in combination with future demands for heating or cooling to determine if there is any combination of current and future heating or cooling demands that exceed a minimum level or number of demands necessary to authorize heating or cooling. A start time for the provision of the heated or cooled water is thereafter determined by the system controller in the event that there is any combination of current and future heating or cooling demands that exceed the minimum level or number of demands necessary to authorize a heating or cooling. The system controller is also operative to implement a changeover between delivery of water conditioned in one way, such as for example heating, to the delivery of water conditioned another way, such as for example cooling.

Claims

1. A process for controlling the provision of conditioned water to a plurality of heat exchangers, under the control of zone controllers, said process comprising the steps of:

periodically polling the plurality of zone controllers for the heat exchangers to obtain information concerning current and future demands for heating or cooling by the zone controllers;

determining whether there is a sufficient predominance of current heating demands from said zone controllers;

determining whether there is a sufficient predominance of current and future demands for heating from said zone controllers when there is not a sufficient predominance of current heating demands;

providing heated water to the heat exchangers in response to a determination that there is a sufficient predominance of current demands for heating or if there is a sufficient predominance of current and future demands for heating from said zone controllers;

determining whether there is a sufficient predominance of current cooling demands from said zone controllers;

determining whether there is a sufficient predominance of current and future demands for cooling from said zone controllers when there is not a sufficient predominance of current cooling demands; and

providing cooled water to the heat exchangers in response to a determination that there is a sufficient predominance of current demands for cooling or if there is a sufficient predominance of current and future demands for cooling from said zone controllers.

2. The process of claim 1 further comprising the step of:

storing in a system controller the information obtained from the zone controllers; and

computing a future heat or cooling demand for any zone controller not having a current heating or cooling demand.

3. The process of claim 2 wherein said step of computing a future heating or cooling demand comprises the step of:

computing a heat start time or a cool start time for any zone controller not having a current heating or cooling demand.

4. The process of claim 3 wherein the information obtained from each zone controller includes the next future setpoint and associated start time for the next future setpoint for each zone controller, a currently sensed temperature for the zone associated with the zone controller, and the heat and cooling factors for the respective zone controller wherein the heat factor defines the amount of time necessary to raise the sensed temperature in the respective zone by one degree and the cooling factor defines the amount of time necessary to lower the sensed temperature in the respective zone by one degree and wherein any heat start time for a zone controller is computed as a function of the difference between the next future setpoint for the zone controller and the current temperature for the zone controller, the difference being multiplied by the heating factor for the zone controller and wherein any cool start time for a zone controller is computed as a function of the difference between the current temperature and the next future setpoint for the zone controller, the difference being multiplied by the cooling factor.

5. The process of claim 3 wherein said step of determining whether there is a sufficient predominance of current and future demands for heating from said zone controllers comprises the steps of:

adding the number of current heat demands in the array of information to the number of heat start times in the array; and

comparing the added number of current heat and future heat start times with a minimum level of required heat demands; and

wherein said step of determining whether there is a sufficient predominance of current and future demands for cooling from said zone controllers comprises the step of;

adding the number of current cool demands in the array of information to the number of cool start times in the array; and

comparing the added number of current cool demands and future cool start times with a minimum level of required cool demands.

6. The process of claim 5 further comprising the steps of:

determining a start time for providing heated water to any heat exchanger associated with a zone controller having a current or future heating demand when there is a sufficient predominance of current and future heating demands; and

determining a start time for providing cooled water to any heat exchanger associated with a zone controller having a current or future cooling demand when there is a sufficient predominance of current and future cooling demands.

7. The process of claim 6 wherein said step of determining a start time for providing heated water to any heat exchanger associated with a zone controller having a current or future heating demand comprises the steps of:

determining the number of current heat demands in the stored information;

determining the number of computed heat start times that need to be counted and combined with the number of current heat demands in the stored information in order to exceed a minimum number of zone controllers necessary to provide heated water;

successively selecting the next to occur heat start time until the number of start times that needed to be counted have been counted; and

selecting the last successively selected next to occur heat start time as the start time for providing heated water.

8. The process of claim 7 wherein said step of determining a start time for providing cooled water to any heat exchanger associated with a zone controller having current or future cooling demand comprises the steps of:

determining the number of current cool demands in the stored information;

determining the number of cool start times that need to be counted and combined with the number of current cooling demands in the stored information in order to exceed a minimum number of zone controllers necessary to be demanding current or future cooling in order to provide cooled water;

successively selecting the next to occur cool start time until the determined number of cool start times that need to be counted have been counted; and

selecting the last successively selected next to occur cool start time as the start time for providing cooled water.

9. The process of claim 1 further comprising the steps of:

switching from providing heated water to providing cooled water to the heat exchangers in response to a determination that the information being received from said zone controllers is continually indicating a sufficient predominance of current or a sufficient predominance of current and future demands for cooling over a predetermined period of time; and

switching from providing cooled water to providing heated water to the heat exchangers in response to a determination that the information being received from said zone controllers is continually indicating a sufficient predominance of current or a sufficient predominance of current and future demands for heating over a predetermined period of time.

10. The process of claim 9 further comprising:

switching to providing cooled water before the predetermined period of time has elapsed in the event that the water being returned for further conditioning is within a predefined range of temperatures; and

switching to providing heated water before the predetermined period of time has elapsed in the event that the water being returned for further conditioning is within a predefined range of temperatures.

11. The process of claim 10 further comprising the steps of:

initiating a tracking of the predetermined period of time that must elapse before the switching to either providing cooled water or the switching to providing heated water; and

delaying said step of initiating the tracking of the predetermined period of time that must elapse before the switching in the event that a second predetermined period of time has not elapsed since the current provision of heated or cooled water to the heat exchanger was initiated.

12. The process of claim 11 wherein said step of providing heated water comprises activating a heating source and wherein said step of providing cooled water comprises activating a cooling source and wherein said step of switching from providing heated water to providing cooled water to the heat exchangers comprises deactivating the cooling source and thereafter activating the heating source after the predetermined period of time has elapsed and wherein said step of switching from providing cooled water to providing heated water comprises deactivating the heating source and thereafter activating the cooling source after the predetermined period of time has elapsed.