Liebert Corporation

Vertiv Corporation

Daniel J Schutte

Benedict J Dolcich

Zhiyong Lin

Roger Noll

Gary A Helmink

Stephen C Sillato

Lou Monnier

John Francis Judge

Timothy J Schrader

Steven M Madara

Pierpaolo Barbato

Giuseppe Dalla Mana

Greg Haggy

Matthew Raven

Gang Xu

Thomas Harvey

Zongtao Lu

David W Douglas

John R Birchmeier

Anfu Zhong

Lewis Marton

Luis A Anjos

Peter M Buckingham

Stephen Sillato

The present disclosure relates to a method for controlling a level of superheat during a pump mode of operation of a refrigeration system, wherein the refrigeration system can operate in either the pump mode or a compressor mode, and has an electronically controlled expansion valve (EEV). A controller obtains a stored, predetermined pump differential pressure range able to be produced by a pump of the system. The controller also obtains a stored, predetermined superheat range, and detects a superheat level. When the detected superheat level is outside of the superheat temperature range, the controller commands adjusting at least one of the EEV and a speed of the pump based on whether the detected superheat level is above or below the superheat range, and whether a current pump differential pressure is above or below the predetermined pump differential pressure range.

System and method to maintain evaporator superheat during pumped refrigerant economizer operation

A cooling system has both pumped refrigerant economization and direct expansion cooling. When outside air temperature is low enough that pumped refrigerant economization can provide enough cooling to satisfy cooling demand, only pumped refrigerant economization cooling is used to provide cooling. When outside air temperature is low enough that pumped refrigerant economization can provide some but not all of the cooling needed to satisfy cooling demand, the pumped refrigerant economization is operated at one hundred percent capacity and the direct expansion cooling is operated at a capacity to provide any supplemental cooling that is needed. If the outside air temperature is high enough that pumped refrigerant economization cannot provide any cooling, then only direct expansion cooling is used to provide cooling.

Cooling system with direct expansion and pumped refrigerant economization cooling

An evaporator for a cooling system has a slab coil having a plurality of refrigerant circuits with each refrigerant circuit being a fin-and-tube assembly that extends across the slab coil. At least one of the refrigerant circuits has a mini-slab circuit extender that has a fin-and-tube assembly that extends across only a portion of the fin-and-tube assembly of that refrigerant circuit and is disposed in front of that portion of the fin-and-tube assembly of that refrigerant circuit.

Fin and tube-evaporator with mini-slab circuit extenders

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

In an aspect, a cooling system has a cooling circuit that includes an evaporator, a condenser, a compressor, a sub-cooler and an expansion device configured in a direct expansion cooling circuit with the sub-cooler coupled in series between an outlet of the condenser and an inlet of the expansion device. The condenser has a micro-channel cooling coil and the sub-cooler has a fin-and-tube cooling coil. In an aspect, the fin-and-tube cooling coil of the sub-cooler has a total hydraulic volume equivalent to the total hydraulic volume of the micro-channel cooling coil of the condenser but the fin-and-tube cooling coil of the sub-cooler has a face area more than two times smaller than a face area of the micro-channel cooling coil of the condenser.

Cooling system having a condenser with a micro-channel cooling coil and sub-cooler having a fin-and-tube heat cooling coil

A method including: determining a cooling value; and comparing the cooling value to an activation point of a lead compressor. The lead compressor is in a tandem set of scroll compressors of a cooling system. The tandem set of compressors comprises a lag compressor. The method further includes: activating the lead compressor when the cooling value is greater than the activation point; activating the lag compressor subsequent to activating the lead compressor; and determining whether conditions exist including: an alarm associated with the lag compressor being generated, and the lead compressor being deactivated. The method further includes deactivating the lag compressor when at least one of the conditions exists in the cooling system.

Scroll compressor differential pressure control during compressor startup transitions

A method including determining whether an OFF criterion is satisfied for a lag compressor of a tandem set of scroll compressors. The tandem set of scroll compressors includes a lead compressor. The method further includes: initiating at least one process when the OFF criterion is satisfied; and maintaining the lag compressor in an ON state for a predetermined period subsequent to the OFF criterion being satisfied. The at least one process includes at least one of: operating the lead compressor at a maximum level; overriding a motor overload protection method, wherein the motor overload protection method protects motors of the lead compressor and the lag compressor; and overriding a proportional integral derivative (PID) method to reduce a speed of a condenser fan. The PID method controls the speed of the condenser fan. A system including the lag compressor module and the lead compressor module.

Scroll compressor differential pressure control during compressor shutdown transitions

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 conditioning unit can allow the blower to be easily translated from a first operable position in the conditioning unit to a second operable position external to the conditioning unit. The translation of the blower does not require the disconnection of the blower and, accordingly, does not require that the blower be disconnected and reconnected to the control system. Such capability can facilitate the installation of the conditioning unit into a variety of applications and allows the purchaser to customize the blower location based on the desired performance. The ability to customize the installation of the conditioning unit without requiring disconnection and reconnection of the blower can reduce the cost and expense associated with the installation into differing applications.

Growing community of inventors

Lewis Center, OH, United States of America

Daniel J Schutte