York International Corporation

Liebert Corporation

Johnson Controls Technology Company

Vertiv Corporation

John Francis Judge

Zhiyong Lin

Benedict J Dolcich

Timothy J Schrader

Harold Robert Schnetzka

Stephen C Sillato

Daniel J Schutte

Roger Noll

Gary A Helmink

Greg Haggy

Zongtao Lu

Douglas Alan Kester

Mahesh Valiya Naduvath

Lou Monnier

Pierpaolo Barbato

Giuseppe Dalla Mana

Curtis Christian Crane

Satheesh Kulankara

Frank E Wills

Paul Marie De Larminat

Thomas Harvey

Israel Federman

Jun Wang

Steven Trent Sommer

Mahesh Valiya-Naduvath

Keith E Starner

Stephen Harold Smith

Frank Highland Hill, Iv

Wanlai Lin

Luc Le Cointe

Mustafa Kemel Yanik

Kenneth E Hickman

Frank H Hill

Craig Ward

James W Holdren

Mark R Geesey

Steven N Roy

Stephen Sillato

Paul De Larminat

A system including a setpoint module, a summer, a control module, and an expansion valve module. The setpoint module is configured to indirectly control sub-cooling of a condenser by adjusting a superheat setpoint based on (i) a return air temperature setpoint or a supply air temperature setpoint, and (ii) an outdoor ambient temperature. The summer is configured to determine an error between the superheat setpoint and a superheat level of a compressor. The control module is configured to generate a control signal based on the error. The expansion valve module is configured to electronically control a state of an expansion valve based on the control signal.

Apparatus and method for subcooling control based on superheat setpoint control

A cooling system has a cabinet and a plurality of separate cooling stages including an upstream cooling stage and a downstream cooling stage. At least the upstream cooling state is a variable capacity cooling stage. Each cooling stage has a cooling circuit. Evaporators of the cooling circuits are arranged in the cabinet so that air passes over them in serial fashion. A controller when a Call for Cooling first reaches a point where cooling is needed, operating the upstream cooling circuit to provide cooling and not the downstream cooling circuit. When the Call for Cooling has increased to a second point, the controller additionally operates the downstream cooling circuit to provide cooling. The cooling capacity at which the upstream cooling circuit is being operated is less than its full capacity when the Call for Cooling reaches the second point.

High efficiency cooling system

A cooling system has a direct expansion mode and a pumped refrigerant economizer mode and a controller. The controller includes a load estimator that estimates real-time indoor load on the cooling system and uses the estimated real-time indoor load to determine whether to operate the cooling system in the pumped refrigerant economizer mode or in the direct expansion mode.

Load estimator for control of vapor compression cooling system with pumped refrigerant economization

An economized refrigeration system includes a main refrigerant circuit having a condenser, an evaporator, an economizer, an expansion device intermediate the condenser and the economizer, and a main compressor fluidly connected by a main refrigerant line. The system also includes an economized refrigerant circuit including an auxiliary compressor system and an auxiliary refrigerant line fluidly connecting the economizer to the auxiliary compressor system and fluidly connecting the main refrigerant line to the auxiliary compressor at a location intermediate the main compressor system and the condenser. The auxiliary compressor system is independently controllable with respect to the main compressor system.

Economized refrigeration system

A system includes an error module configured to integrate a difference between a superheat signal and a superheat setpoint to generate an error signal, wherein the superheat signal indicates suction superheat values of a compressor. A comparison module is configured to compare the error signal to a first predetermined threshold to generate a first comparison signal based on the comparison. A zero-crossing module is configured to compare a first count value to a second predetermined threshold to generate a second comparison signal. The first count value is generated based on at least one comparison between the superheat signal and the superheat setpoint. A setpoint module is configured to adjust the superheat setpoint based on the first comparison signal and the second comparison signal.

Expansion valve setpoint control systems and methods

A cooling system has a plurality of separate cooling stages including an upstream cooling stage having an upstream cooling circuit and a downstream cooling stage including a downstream cooling circuit, which are each a direct expansion cooling circuit including a tandem compressor. Each tandem compressor includes a fixed capacity compressor and a variable capacity compressor. A controller controls the fixed capacity compressor and variable capacity compressor of each tandem compressor based on a Call for Cooling, which of a plurality of ranges the Call for Cooling falls within, and whether the Call for Cooling is ramping up or ramping down.

Multi-stage cooling system with tandem compressors and optimized control of sensible cooling and dehumidification

A universal control panel for controlling operation of a cooling component. The universal control panel may have a variable frequency drive (VFD) that incorporates an input voltage and frequency sensing circuit; and logic, memory and communications circuits. The VFD accepts a plurality of differing input signals, analyzes the input signals and generates an output signal having a desired voltage and frequency to provide real time control over an electrical component operably associated with the cooling component. The VFD controls the cooling component in relation to changes in at least one of sensed pressure and a sensed temperature of a fluid, to dampen response of the electrical component, to thus achieve more efficient use of the cooling component being used to cool the fluid.

System and method for forming universal control panel

A falling film evaporator is provided for use in a two-phase refrigeration system or process system. The evaporator includes a shell having an upper portion, a lower portion, and a tube bundle having tubes extending substantially horizontally in the shell. A hood is disposed over the tube bundle, the hood having an upper end adjacent the upper portion above the tube bundle, the upper end having opposed substantially parallel walls extending toward the lower portion, the walls terminating at an open end opposite the upper end. Once liquid refrigerant or liquid refrigerant and vapor refrigerant is deposited onto the tube bundle, the substantially parallel walls of the hood substantially prevent cross flow of refrigerant vapor or liquid and vapor between the tubes of the tube bundle.

Falling film evaporator

A liquid refrigerant drainage mechanism is described for use in a flooded evaporator to mitigate liquid carryover. The drainage mechanism can trap liquid refrigerant droplets, create a liquid column to overcome a pressure difference across the mechanism and drain liquid back to the pool in the evaporator. The drainage mechanism is disposed in a suction baffle, and has a mesh pad and a tapered pipe secured to the bottom of the baffle. The pipe has a drainage aperture at one end to allow the accumulated liquid refrigerant to return to the refrigerant pool below. The mesh pad helps to separate liquid droplets that coalesce and fall into the tapered pipe. By using this liquid drainage mechanism in conjunction with a suction baffle, liquid carryover can be reduced and chiller performance improved.

Drainage mechanism for a flooded evaporator

A system and method are provided for variable speed operation of a screw compressor to obtain increased capacity and efficiency. The screw compressor is connected to an induction motor driven by a variable speed drive, wherein the screw compressor has a variable output capacity that is dependent on the output speed of the motor. To obtain increased capacity and efficiency, the screw compressor is operated at a speed greater than the screw compressor's rated speed and does not include a slide valve. The maximum operating speed of the screw compressor, which speed is greater than the rated speed, is related to the maximum operating speed of the motor when operated at a voltage and frequency provided by the variable speed drive that is greater than the motor's rated voltage and frequency in a constant flux or constant volts/Hz mode.

System and method for variable speed operation of a screw compressor

A chiller system includes a refrigerant loop, the refrigerant loop further including a compressor, an air-cooled condenser arrangement and an evaporator arrangement connected in a first closed refrigerant loop. A motor is connected to the compressor to drive the compressor, a drive is connected to the motor to power the motor and a power/control panel controls the refrigerant loop. The power/control panel and the condenser arrangement are connected in a second closed coolant loop. The second closed coolant loop provides cooling to the enclosure and/or components within the enclosure disposed on a chill plate. Condensation is substantially prevented from forming inside the enclosure, despite the enclosure lacking a humidity control device.

Electronic component cooling system for an air-cooled chiller

A heat exchanger assembly for use in an HVAC system is provided. The heat exchanger assembly includes: a shell-type casing; a plurality of tubes located inside the shell-type casing, each of the tubes having an outer surface and an irregular inner surface; and a plurality of electrodes. Each electrode is located inside one of the corresponding tubes to create a space between the electrode and the inner surface of the tube. A first fluid is located in each space between the electrodes and the inner surfaces of the tubes. A second fluid is located in a space between the tubes and the shell-type casing to flow across the outer surfaces of the tubes. A voltage is applied on the electrodes in order to increase the rate of heat transfer between the first fluid and the second fluid. The invention also includes a method of exchanging heat between a heat transfer fluid and a refrigerant in a shell and tube heat exchanger.

Heat exchanger assembly with enhanced heat transfer characteristics

An apparatus and associated method for discharging a fluid and a liquid separated from the fluid from an outlet chamber of a heat exchanger. The outlet chamber is configured to collect the separated liquid. The outlet chamber is in fluid communication with an outlet opening disposed on an exit surface of the outlet chamber. The apparatus includes a plate that is positionable in the outlet chamber adjacent to the exit surface to form a channel between the plate and the exit surface. The plate is configured to protrude over the outlet tube opening so that the fluid flowing through the outlet chamber and into the outlet opening pulls the liquid collected in the outlet chamber through the channel and out through the outlet opening with the fluid. Because of the plate protruding over the outlet opening, the fluid exiting directly from the outlet chamber through the outlet opening must flow through a decreased area. This decreased area produces the vena contracta effect and creates a low pressure region. The low pressure region draws the collected liquid through the channel and discharges it through the outlet opening with the fluid.

Apparatus and method for discharging fluid

This invention increases efficiency of a refrigeration system by maximizing the cooling of the condenser and reducing unnecessary work done by the compressor. In air cooled systems it will also increase the stability of the fans by reducing fan cycling. The fan controller will utilize an algorithm that will consider the following inputs: oil pressure, compressor suction pressure, expansion valve position, compressor loading, last compressor loading change, and current fan stage. The algorithm uses fuzzy logic to characterize the inputs and generates an output that controls the system cooling fans.

Method and apparatus for controlling the removal of heat from the condenser in a refrigeration system

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Galena, OH, United States of America

John Francis Judge