Demand flow pumping

A controller for controlling one or more pumps of a chilled water plant comprising:

• an input configured to receive sensor information from one or more sensors;
• a processor configured to control a flow rate provided by the one or more pumps to maintain a Delta T across a component of the chilled water plant, wherein the processor increases or decreases the flow rate to maintain the Delta T based on the sensor information and generates one or more signals to control the flow rate provided by the one or more pumps, the Delta T comprising an entering temperature and a leaving temperature;
• and wherein the processor is configured to perform a critical zone reset by lowering the Delta T in response to sensor information indicating additional cooling capacity is desired at the component;
• and
• an output configured to send the one or more signals to the one or more pumps.

A method for efficient operation of a chilled water plant comprising:

• setting a chilled water Delta T comprising a chilled water entering temperature and a chilled water leaving temperature at one or more components of the chilled water plant;
• controlling chilled water flow rate through the one or more components to maintain the chilled water Delta T across the one or more components, wherein the chilled water flow rate is controlled by one or more chilled water pumps;
• and
• performing a critical zone reset to adjust the chilled water Delta T when one or more triggering events occur, wherein the chilled water Delta T is reset by an action selected from the group consisting of adjusting the chilled water entering temperature and adjusting the chilled water leaving temperature;
• wherein the control of chilled water flow rate through the one or more components to maintain the chilled water Delta T reduces Low Delta T Syndrome at the chilled water plant, and wherein the chilled water Delta T at the one or more chilled water plant components is maintained by increasing the chilled water flow rate or decreasing the chilled water flow rate.