Dunham-bush

Other

Copeland Corporation

Svenska Rotor Maskiner Ab

Durham-bush, Inc.

David N Shaw

Joseph A Gagnon

David J First

Giridhari L Agrawal

Donald D Schaefer

Clifford T Bulkley

Norman A Gagnon

A boosted source heat pump (BSHP) is presented having a primary compressor, a booster compressor, an economizer, and a lubricant management system. At least the primary compressor is a twin-single compressor. The lubricant management system includes traps to prevent migration of lubricant to a non-operating compressor, and aspiration tubes from the sump to the low pressure intake zone to each compressor.

Boosted air source heat pump

A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The male rotor is driven by a motor, in other words the male rotor is the drive rotor. The male rotor has a plurality of lobes which intermesh with a plurality of flutes on each of the female rotors. The male rotor comprises an inner cylindrical metal shaft with an outer composite material ring mounted thereon. The ring includes the lobes of the male rotor integrally depending therefrom. The lobes of the male rotor being comprised of a composite material allows positioning of the female rotors at a small clearance from the male drive rotor. This clearance is small enough that the liquid refrigerant itself provides sufficient sealing, cooling and lubrication. The positioning of the female rotors on opposing sides of the male rotor balances the radial loading on the male rotor thereby minimizing radial bearing loads. The interface velocity between the male and female rotors during operation is low, whereby damage suffered as a result of lubrication loss is reduced. The compressor includes a housing having an inlet housing portion, a main housing portion and a discharge housing portion. An induction side plate and a discharge side plate are mounted on the male rotor. The outside diameter of the induction plate is equal to the root diameter of the male rotor. The outside diameter of the discharge plate is equal to the crest diameter of the male rotor. These plates serve two purposes, to secure the male rotor components and to equalize suction pressure at both ends of the male rotor, thereby virtually eliminating the thrust loads. Discharge porting is defined in the discharge housing portion wherein trap pocket relief is provided.

Multi-rotor helical-screw compressor

A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The compressor includes a housing and a thrust balance configuration. The thrust balance configuration includes a thrust balance disc mounted to a male rotor shaft in a discharge housing of the compressor. The thrust balance disc is exposed to fluid from the compressor at high pressure. The outside diameter of the thrust balance is sized to provide sufficient area to react thrust loads produced by the first rotor. The thrust balance configuration serves to balance the thrust loads imparted on the male rotor and allows for full axial discharge porting.

Multi-rotor helical-screw compressor with discharge side thrust balance device

A system for controlling the amount of foam ingested to a compressor of a cooling system is presented. The present invention utilizes a heated thermistor to control an electrically positioned expansion valve feeding liquid refrigerant to a system evaporator. The thermistor is controlled to be a few degrees warmer than the discharge saturation temperature of the refrigerant exiting the compressor. The saturation temperature corresponding to the compressor discharge pressure is calculated by a microprocessor and compared to the thermistor temperature. If the difference is greater or less than desired, the microprocessor will send the proper signals to the electrically positioned expansion valve thereby controlling the rate of foam ingested by the compressor.

Evaporator generated foam control of compression systems

A helical-screw rotary compressor having a twin rotor configuration or a multi-rotor (i.e., at least three) configuration with defined compressor induction and discharge ends has at least one unloader piston disposed at said compressor discharge end. The unloader pistons being opened and closed in fine discrete steps by microprocessor controlled stepping motors which drive linear actuators

Variable capacity vapor compression cooling system

A compressor in accordance with the present invention includes a male rotor which is axially aligned with and in communication with two female rotors. The compressor includes a housing and a thrust balance configuration. The thrust balance configuration includes a stepped up portion mounted at the suction end of the male rotor and is exposed to fluid from the compressor at high pressure. The outside diameter of the thrust balance configuration is generally less than the crest diameter of the male rotor and sized to provide sufficient area to react thrust loads produced by the first rotor. The thrust balance configuration serves to balance the thrust loads imparted on the male rotor and allows for full axial discharge porting.

Multi-rotor helical-screw compressor with thrust balance device

A compressor with rotor unloading is presented. The compressor having a housing for supporting a multi-rotor configuration (e.g., a male rotor and two axially aligned female rotors) and a drive motor. A discharge disk is mounted at the discharge end of the male rotor. The length of the male rotor is slightly longer than the length of the female rotors, thereby providing axial clearance between the female rotors and the discharge disk. Lubrication is leaked (or flashed) through these clearances to upper bearings. The motor is supported in the compressor housing. Evaporated refrigerant from the evaporator is inducted into the compressor. The vapor phase refrigerant is compressed by the compressor. The compressed vapor phase refrigerant is then presented to a condenser, condensing the refrigerant to the liquid phase. Thereafter, liquid phase refrigerant is delivered through an expansion valve to the evaporator. The motor, bearings and the compression process itself are cooled and lubricated by the oil in the vapor refrigerant. The unloading is accomplished by allowing selective axial movement of the female rotors of the compressor to effectively reduce/prevent compression at that rotor. The axial movement is actuated by a stepper motor. The expansion valve is actuated and the female rotors are unloaded (i.e., the stepper motors are driven) in response to microprocessor control. Accordingly, the above describes a complete cycle which can be capacity varied.

Multi-rotor helical screw compressor with unloading

A boosted air source heat pump system is presented having a primary compressor, a booster compressor and an economizer. On activation of the heat pump system, the primary compressor is operated. When the primary compressor cannot meet the demand, the booster compressor is activated, but only upon receipt of a signal enabling the operation of the booster compressor. The booster compressor is preferably a variable speed booster, and its speed is controlled to be at or between an absolute minimum speed and an absolute maximum speed. The booster may be on the low side or the high side of the primary compressor. The operation of the economizer may be modulated to meet the demand on the system.

An expansion/separation compressor system is presented for a multi-rotor compressor configuration. In accordance with the present invention the rotors are disposed in a shell having open and closed off portions for providing expansion, compression and separation. The closed off portions depend from or are attached to other suitable compressor structure including the induction or discharge plates. In an embodiment the expansion portion is comprised of a sliding valve. Separation is achieved when the flute and respective open shell portion expose the fluid to basic plenum pressure. The fluid is essentially removed by centrifugal force through the opening in the shell. The compressor is mounted to an evaporator and a control system is provided to regulate the temperature of water in the evaporator thereby controlling the rate of evaporation of liquid phase refrigerant in the evaporator. The liquid phase refrigerant is expanded between the rotors and respective shell portions to a desired volume. Further, the present invention presents foam generated from the liquid phase refrigerant to an opening in the shell at the induction side of the compressor for cooling, sealing and lubrication purposes. In accordance with the present invention the capacity of above described system can be varied without mechanical unloading.

Expansion/separation compressor system

A plurality of variable speed centrifugal compressors operated in parallel form an HVAC or refrigeration system. The compressors are operated at proportionally synchronized speeds throughout their range of operation.

Variable speed parallel centrifugal compressors for HVAC and

A primary compressor and a booster compressor connected in series is presented. A first conduit connects the low side of a heating/cooling or refrigeration system to the inlet of the booster compressor, the outlet of the booster compressor and the inlet of the primary compressor. A second conduit connects the outlet of the primary compressor to the high side of the system. The first conduit includes a check valve for closing or opening the connection between the first conduit and the outlet of the booster compressor. A sump conduit is positioned near the bottom of the primary and booster compressors to allow lubricant to flow from the booster compressor to the primary compressor.

Series connected primary and booster compressors

A variable capacity vapor compression cooling system is presented. In the system of the present invention, air conditioning requirements are entered into a microprocessor which controls the system. Liquid phase refrigerant entering an evaporator is regulated by a microprocessor controlled electronic expansion valve. Evaporated refrigerant is delivered to a pair of compressors from the evaporator. The motors for the compressors are controlled by a controller. Each of the compressors has a feed back loop attached thereto for feeding back some of the inducted vapor phase refrigerant. The amount of vapor fed back in each loop is regulated by a corresponding microprocessor controlled multi-purpose valve. The compressed vapor phase refrigerant is then presented to a condenser which condenses the refrigerant to the liquid phase which is used for cooling, as is well known in the art. Thereafter, liquid phase refrigerant is presented to an economizer where vapor phase refrigerant (i.e., flash gas) is drawn off. The amount of vapor phase refrigerant drawn off is regulated by a microprocessor controlled electronic expansion valve. This vapor phase refrigerant is presented to the multi-purpose valves where it is directed to the respective compressors. The liquid phase refrigerant is delivered to the evaporator with the flow thereof being regulated by a microprocessor controlled electronic expansion valve. Accordingly, the above describes a complete cycle which can be capacity varied without unloading of the compressors, as described more completely below. It is an important feature of the system of the present invention that capacity is varied without unloading the compressors.

A helical-screw rotary compressor having a twin rotor configuration or a multi-rotor (i.e., at least three) configuration with defined compressor induction and discharge ends has at least one unloader piston disposed at said compressor discharge end with an economizer injection port therein. The unloader pistons being opened and closed in fine discrete steps by microprocessor controlled stepping motors which drive linear actuators.

Growing community of inventors

Unionville, CT, United States of America

David N Shaw