Trane International Inc.

American Standard International Inc.

Lee R Cline

Susanna Staubly Hanson

Michael C A Schwedler

Brian A Kirkman

Brian J Fiegen

Brian Thomas Sullivan

Scott A Munns

Christopher R Vause

John Arthur Murphy

Multi-compressor chiller systems can be efficiently operated by determining real time efficiency curves for the compressors currently in operation, along with any compressors that may be added to address demand, and using these efficiency curves to determine changes to compressor operation to improve efficiency in meeting chiller demand. The efficiency curves can be parabolic curves. The data used to determine the efficiency curves can be obtained through operation at a variety of lift points and a variety of load points within those lift points. The efficiency curves can be solved to find intersections where there may be staging points for adding or subtracting compressors from operation to efficiently meet demand. This operation can be automated through a controller of a control system for the multi-compressor chiller system.

Systems and methods for modeling of chiller efficiency and determination of efficiency-based staging

A packaged heating and/or cooling unit for a production module for a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The packaged unit includes a heat pump configured to provide heating and/or cooling; a connection to a piping distribution system to selectively connect to a hot fluid circuit and/or a cold fluid circuit; and a controller. The controller is configured to connect to and receive a signal from a building automation system for a heating requirement or a cooling requirement, and further configured to selectively control connection to either the hot fluid circuit or the cold fluid circuit and independently control the packaged heating and/or cooling unit based on the signal from the building automation system for either the heating requirement or the cooling requirement.

Multi-feed chiller-heater production module and method of controlling the same

Systems, apparatus and methods for efficiently operating a chiller plant while minimizing or eliminating the occurrence of centrifugal compressor surge. Taking into account chiller design specifications and current operating conditions, a compressor lift point at which surge is predicted to occur is established. Minima and maxima for various chiller setpoints that avoid or eliminate the occurrence of compressor surge are imposed on setpoints provided by a conventional optimizing chiller controller. The chiller system is operated in accordance with the resultant anti-surge setpoints. Energy savings is realized by modulating coolant tower flow to enable the compressor to operate at near-surge conditions while preventing the onset of actual surge.

Chiller plant with dynamic surge avoidance

Chiller control systems and methods for chiller control use iterative modeling of cooling towers, heat exchangers, and pumps to determine the feasibility of integrated free cooling and the ability to take advantage of free cooling. The control systems and control methods can further include selecting the parameters for operating in the free cooling or integrated free cooling mode to improve efficiency and/or reduce energy consumption when operating in these modes. The models can have inputs and outputs that feed into one another, and converge at a solution over multiple iterations. The feasibility of integrated free cooling can be based on providing cooling to a cooling load process fluid at a heat exchanger. The availability of free cooling can be based on the cooling provided at the heat exchanger achieving a target temperature for the cooling load process fluid.

Systems and methods for controlling free cooling and integrated free cooling

Control systems and methods for control of heating, ventilation, air conditioning, and refrigeration (HVACR) systems that include cooling and one or both of heating and heat recovery can include adaptive and balanced modes for each of heating and cooling operations. The adaptive heating and cooling modes each respectively include controlling the HVACR system to achieve a target temperature for the respective heating or cooling process fluid and to unload or stop the compressor when the temperature of a the other of the cooling or heating process fluid exceeds a threshold. The balanced heating and cooling modes respectively include controlling a quantity of flow of the cooling or heating process fluids to meet balanced heating or cooling target temperatures for the respective heating or cooling process fluids and also the other of the cooling or heating process fluid.

Heat recovery or heating unit load balance and adaptive control

Cooling systems and methods of controlling a cooling system which includes one or more pumps and one or more fans, wherein the pumps and the fans are controlled by a controller. The controller controls the cooling system by a determination of an operation of the cooling system for sequencing activations, deactivations, and/or controlling parameters of the pumps, the fans, and/or other component(s) of the cooling system based on a first sensitivity of a power input as a function of lift, and a second sensitivity of a power input as a function of lift.

System and method for controlling a cooling system

Systems, apparatus and methods for operating a chiller plant while minimizing or eliminating the occurrence of centrifugal compressor surge. Taking into account chiller design specifications and current operating conditions, a compressor lift point at which surge is predicted to occur is established. Minima and maxima for various chiller setpoints that avoid or eliminate the occurrence of compressor surge are imposed on setpoints provided by a conventional optimizing chiller controller. The chiller system is operated in accordance with the resultant anti-surge setpoints. Coolant tower flow is modulated to enable the compressor to operate at near-surge conditions while preventing the onset of actual surge.

A cascade heat recovery system connects an evaporator from a heating unit to a recovery condenser of the cooling unit, where the recovery condenser is different from a cooling condenser of the cooling unit, and/or connects the evaporator of the heating unit to the cooling loop of the cooling unit, for example in fluid communication with the evaporator of the cooling unit. Both configurations allow the heating unit to be isolated or decoupled from the heat rejection circuit on which the cooling condenser runs. The use of either or both configurations, depending on the operating conditions, can use heat rejected by the evaporator of the cooling unit to be available to the heating unit, so as to provide lift to the heating unit and improve its operating efficiency.

Cascading heat recovery using a cooling unit as a source

A chiller plant including at least two chillers operating at different temperatures are disclosed. Process fluid circuits of the chillers can form fluid communication when, for example, one or more of the at least two chillers may fail, so that the other chiller(s) of the at least two chillers may provide backup operation to the failed chiller(s).

Chiller plant

A multi-mode, bi-directional cascade heat pump system, according to some examples, includes at least two chillers each being part of a unidirectional refrigerant circuit. The system includes heat exchangers each of which are dedicated to operate as just a condenser or as just an evaporator, regardless of the system's operating mode. In some modes, a secondary fluid transfers heat between the condenser of one chiller and the evaporator of another chiller before the fluid returns to a secondary fluid source such as, for example, a geothermal borefield or a conventional water source. In some embodiments, fluid is withdrawn from a borefield by way of a pump having a speed that varies to maintain a desired fluid temperature and/or a desired heat transfer rate at the borefield. The heat pump system includes means for minimizing flow through the borefield and for minimizing unnecessary mixing of relatively high and low temperature fluid.

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West Salem, WI, United States of America

Lee R Cline