Cool storage supervisory controller

Claim 1

For a building having a HVAC system which includes chiller means, pump means, storage means, heat exchanging means and a chilled water loop between said chiller means, storage means, and heat exchanging means, an operating method for a cool storage supervisory controller for controlling the HVAC system where the controller includes a direct digital controller, a first control interface between said direct digital controller and said chiller means, a second control interface between said direct digital controller and said pump means, a third controller interface between said direct digital controller and said ice storage means, computing means including data input means, data storage means, memory means, display means, and processing means and a two-way data transfer gateway for communication between said computing means and said direct digital controller, the operating method comprising the steps of: (a) operating the computing means to determine the predicted ambient temperatures from a projected high temperature and projected low temperature input by the user, historical data of actual temperatures from the current and previous cycles stored by the storage means, and an array of shape factors which assume a daily temperature pattern can be established by each hour's position relative to high and low temperatures; (b) operating the data input means to receive data including predicted building load requirements and power company rate structure information; and (c) determining a new shape factor by operating the computer means to: (i) calculate temperature charges for the preceding cycle, (ii) test these changes for reasonableness, (iii) if reasonable, calculate current shape factors using the temperatures from the previous cycle and the temperature changes, (iv) determine whether the current shape factors are reasonable, and (v) if reasonable, calculate a new shape factor profile from the previous and current profiles using weighted averages; and (d) operating the direct digital controller to implement a charge/discharge strategy for the storage means where the strategy is a function of the predicted ambient temperatures, the predicted building load requirements and the rate structure information.