A pulsed modulated capacity modulation system for refrigeration, air conditioning or other types of compressors is disclosed in which suitable valving is provided which operates to cyclically block flow of suction gas to a compressor. A control system is provided which is adapted to control both the frequency of cycling as well as the relative duration of the on and off time periods of each cycle in accordance with sensed system operating conditions so as to maximize the efficiency of the system. Preferably the cycle time will be substantially less than the time constant of the load and will enable substantially continuously variable capacity modulation from substantially zero capacity to the full capacity of the compressor. Additional controls may be incorporated to modify one or more of the motor operating parameters to improve the efficiency of the motor during periods of reduced load.
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29. A method of modulating the capacity of a compressor forming a part of a cooling system to accommodate varying cooling load conditions comprising:
sensing an operating parameter of said cooling system, said parameter being indicative of the system load;
determining a cycle frequency of and a maximum time duration which will minimize variation in the suction pressure of refrigerant being supplied to said compressor;
determining a first time period during which suction gas will be supplied to said compressor and determining a second time period during which suction gas will be prevented from flowing to said compressor, said first and second time periods being equal to said cycle frequency; and
pulsing a valve between open and closed positions for said first and second time periods respectively to thereby modulate the capacity of said compressor in response to said system operating parameter; and
varying a motor operating parameter when said valve is in said closed position.
1. A capacity modulated compressor comprising:
a compression mechanism disposed between a discharge passage and a suction chamber, said compression mechanism having a compression chamber therein, a suction inlet for supplying suction gas to the said compression chamber and a movable member operative to vary the volume of said compression chamber;
a power source operatively connected to effect movement of said movable member to thereby compress gas drawn into said compression chamber through said suction inlet;
a valve disposed in said suction chamber and provided in the suction gas flow path to said compression mechanism, said valve being operable between open and closed positions to cyclically allow and prevent flow of suction gas into said compression chamber; and
control apparatus for actuating said valve between said open and closed positions, said control apparatus being operative to cycle said valve for a time duration such that its cycle time is substantially smaller than the time constant of the load on said compressor.
0. 76. A capacity modulated compressor comprising:
a compression mechanism disposed between a discharge passage and a suction chamber, said compression mechanism having a compression chamber therein, a suction inlet for supplying suction gas to said compression chamber and a movable member operative to vary the volume of said compression chamber;
a power source disposed in said suction chamber and operatively connected to effect movement of said movable member to thereby compress gas drawn into said compression chamber through said suction inlet;
a valve assembly mounted to said compression mechanism and including a valve member provided in a suction gas flow path to said compression mechanism, said valve being operable between open and closed positions to cyclically allow and prevent flow of suction gas into said compression chamber; and
control apparatus for actuating said valve between said open and closed positions, said control apparatus being operative to cycle said valve for a time duration such that its cycle time is substantially smaller than the time constant of the compressor load.
17. A capacity modulated compressor comprising:
a hermetic shell including a suction chamber;
a compression mechanism disposed within said shell, said compression mechanism including a compression chamber defined in part by a moveable movable member, said moveable movable member operating to vary the volume thereof;
a drive shaft rotatably supported within said shell and drivingly coupled to said movable member;
a motor disposed in said suction chamber and operable to rotatably drive said drive shaft;
a suction inlet passage for supplying suction gas to said compression chamber from a source remote from said shell;
a valve assembly including a valve member within said suction inlet passage, said valve member being actuable between an open position to allow flow of suction gas through said inlet passage and a closed position to substantially prevent flow of suction gas through said suction inlet passage;
a controller for cyclically actuating said valve member to an open position for first predetermined time periods and to a closed position for second predetermined time periods, the ratio of said first predetermined time period to the sum of said first and second predetermined time periods being less than a given load time constant and determining the percentage modulation of the capacity of said compressor.
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is turn in in turn is rotatably supported by upper and lower bearings 68 and 70. A compression rotor 72 is eccentrically mounted on and adapted to be driven by crankshaft 66. Compression rotor 72 is disposed within cylinder 74 provided in housing 76 and cooperates with vane 78 (shown in
In order to incorporate the pulse width capacity modulation system of the present invention into rotary compressor 54, a valve assembly 84 is provided being disposed within shell 56 and between suction fitting 82 and suction gas flow path inlet passage 80. Operation of valve assembly 84 is controlled by a control module 86 which receives signals from one or more sensors 88 indicative of the system operating conditions.
Operation of valve assembly 84, control module 86 and sensor 88 will be substantially identical to that described above with valve assembly 84 operating under the control of control module 86 to cyclically open and close to thereby modulate the flow of suction gas into cylinder 74. As with compressor 10, both the cycle frequency as well as the relative duration of the open and closed portions of the cycle may be varied by control module 86 in response to system operating conditions whereby the system efficiency may be maximized and the capacity varied to any desired capacity between zero and full load.
Compressor assembly 146 includes a mean bearing housing 152 secured within and supported by outer shell 150, an orbiting scroll member 154 movably supported on bearing housing 152 and a nonorbiting scroll member 156 axially movably secured to bearing housing 152. Scroll members 154 and 156 each include end plates 158 and 160 from which interleaved spiral wraps 162 and 164 extend outwardly. Spiral wraps 162 and 164 together with end plates 158 and 160 cooperate to define moving fluid pockets 166, 168 which decrease in size as they move from a radially outer position to a radially inner position in response to relative orbital movement between scroll members 154 and 156. Fluid compressed within the moving fluid pockets 166, 168 is discharged through a centrally located discharge passage 170 provided in nonorbiting scroll member 156 into a discharge chamber 172 defined by the upper portion of hermetic shell 150 and muffler plate 174 and thereafter is supplied to the system via discharge fitting 176. An Oldham coupling is also provided acting between scroll members 154 and 156 to prevent relative rotation therebetween.
A drive shaft 180 is also provided being rotatably supported in bearing housing 152 and having one end thereof drivingly coupled to orbiting scroll member 154. A motor rotor 182 is secured to drive shaft 180 and cooperates with motor stator 184 to rotatably drive drive shaft 180. As thus far described, scroll compressor 144 is typical of scroll type compressors and will operate to draw fluid to be compressed flowing into hermetic shell 150 via inlet 186 into the moving fluid pockets via suction inlet 188 provided in nonorbiting scroll member 156, compress same and discharge the compressed fluid into discharge chamber 172.
In order to incorporate the pulse width capacity modulation system into scroll compressor 144, a valve assembly 190 is provided being positioned in overlying relationship to suction inlet 188 so as to be able to selectively control flow of fluid to be compressed into respective moving fluid pockets 166 and 168. Operation of valve assembly 190 is controlled by control module 192 in response to signals received from one or more sensors 194 in substantially the same manner as described above. It should be noted that while the present invention has been shown and described with reference to a scroll compressor in which the hermetic shell is substantially at suction pressure, it may also be easily incorporated in other types of scroll compressors such as those in which the interior is at discharge pressure or in which both scrolls rotate about radially offset axes.
As may now be appreciated, the pulsed capacity modulation system of the present invention is extremely well suited for a wide variety of compressors and is extremely effective in providing a full range of modulation at relatively low costs. It should be noted that if desired the pulsed capacity modulation system of the present invention may also be combined with any of the other known types of capacity modulation systems for a particular application.
In the above embodiments, it is intended that the compressor continue to be driven while in an unloaded condition. Obviously, the power required to drive the compressor when unloaded (no compression taking place) is considerably less than that required when the compressor is fully loaded. Accordingly, it may be desirable to provide additional control means operative to improve motor efficiency during these periods of reduced load operation.
Such an embodiment is shown schematically in
It should also be noted that while each of the embodiments has been described as incorporating a solenoid valve which operates to control the flow of pressurized discharge gas to the suction gas flow control valve for controlling suction gas flow, it is also possible to substitute other types of valves therefor such as, for example, solenoid valves by themselves or any other suitable valving arrangement. It is, however, believed that the use of a solenoid valve for controlling the flow of a pressurized fluid such as discharge gas to the suction control valve is preferred because it allows for application of greater actuating forces to the suction gas control valve and hence faster operation thereof. An exemplary embodiment of such a valve assembly is shown and will be described with reference to
As shown in
Solenoid valve assembly control valve 106 includes a housing 108 within which is provided a valve chamber 110 having a valve member 112 movably disposed therein. A pressurized fluid supply line 114 opens into chamber 110 adjacent one end thereof and a vent passage 116 opens outwardly from chamber 110 adjacent the opposite end thereof. An outlet passage 118 is also provided opening into chamber 110 approximately midway between the opposite ends thereof. Valve member 112 is secured to one end of plunger 120 the other end of which extends axially movably along hermetically sealed bore 121 about which a solenoid coil 122 is positioned. As shown, plunger 120 will be biased into the position shown in which valve member 112 overlies and closes off pressurized fluid supply line 114 and outlet passage 118 is in open communication with vent passage 116. When solenoid coil 122 is energized, shaft plunger 120 will operate to move valve member 112 into a position in which it overlies and closes off vent passage 116 and allows open communication between pressurized fluid supply line 114 and outlet 118. The opposite end of pressurized fluid supply line 114 will be connected to a suitable source of pressurized fluid such as for example discharge gas from the compressor.
Pressure actuated valve assembly 104 includes a housing 124 having a cylinder 126 provided therein within which piston 128 is movably disposed. A shaft 130 has one end connected to piston 128 and extends from cylinder 126 through bore 132 into a chamber 134 provided in housing 124. A valve member 136 is secured to the end of shaft 130, is positioned within chamber 134 and is movable by shaft 130 into and out of sealing engagement with valve seat 138 provided on partition 140 so as to selectively control flow of suction gas from chamber 134 into chamber 142 and then through outlet 144 outlet 145. An inlet 146 inlet 147 is provided for supplying suction gas to chamber 134.
Fluid outlet line 118 opens into one end of cylinder 126 and serves to provide pressurized fluid thereto bias piston 128 in a direction such that valve 136 moves into sealing engagement with valve seat 138 to thereby interrupt the flow of suction gas from inlet 146 to outlet 144 inlet 147 to outlet 145. A return spring 148 return spring 149 is also provided within cylinder 126 which serves to bias piston 128 in a direction so as to move valve member 136 out of sealing engagement with valve seat 138 in response to venting of the pressurized fluid from cylinder 126.
In operation, when control module 50 determines that capacity modulation is in order, it will operate to energize solenoid control valve 106 thereby moving valve 112 to the right as shown and allowing pressurized fluid to flow through chamber 110 to cylinder 126. This pressurized fluid then operates to move piston 128 in a direction to close valve 136 thereby preventing further flow of suction gas to the compression mechanism. When solenoid control valve 106 is deenergized by control module 50, valve 112 will move into a position to interrupt the supply of pressurized fluid to cylinder 126 and to vent same via passage 116 thereby enabling return spring 148 return spring 149 to move piston 128 in a direction to open valve member 136 such that the flow of suction gas to the compressor is resumed.
It should be noted that valve assembly 102 is exemplary only and any other suitable arrangement may be easily substituted therefor. As noted before, in order to facilitate rapid response to capacity modulation signals, it is desirable that the suction flow shut off valve be located as close to the compression chamber as possible. Similarly, the pressurized fluid supply line and vent passages should be sized relative to the volume of the actuating cylinder being supplied thereby to ensure rapid pressurization and venting of same.
It will be appreciated by those skilled in the art that various changes and modifications may be made to the embodiments discussed in this specification without departing from the spirit and scope of the invention as defined by the appended claims.
Patent | Priority | Assignee | Title |
10094600, | Sep 13 2012 | Emerson Climate Technologies, Inc. | Compressor assembly with directed suction |
10344761, | Oct 29 2013 | Emerson Climate Technologies, Inc. | Rotary compressor with vapor injection system |
10378533, | Dec 06 2011 | BITZER US, Inc. | Control for compressor unloading system |
10675950, | Nov 18 2013 | THERMO KING LLC | System and method of temperature control for a transport refrigeration system |
10928108, | Sep 13 2012 | Emerson Climate Technologies, Inc. | Compressor assembly with directed suction |
10995974, | Sep 13 2012 | Emerson Climate Technologies, Inc. | Compressor assembly with directed suction |
11209000, | Jul 11 2019 | Emerson Climate Technologies, Inc. | Compressor having capacity modulation |
11236748, | Mar 29 2019 | Emerson Climate Technologies, Inc. | Compressor having directed suction |
11248605, | Jul 28 2020 | Emerson Climate Technologies, Inc.; EMERSON CLIMATE TECHNOLOGIES, INC | Compressor having shell fitting |
11619228, | Jan 27 2021 | Emerson Climate Technologies, Inc. | Compressor having directed suction |
11767838, | Jun 14 2019 | COPELAND LP | Compressor having suction fitting |
12180966, | Dec 22 2022 | COPELAND LP | Compressor with funnel assembly |
8157538, | Jul 23 2007 | EMERSON CLIMATE TECHNOLOGIES, INC | Capacity modulation system for compressor and method |
8308455, | Jan 27 2009 | EMERSON CLIMATE TECHNOLOGIES, INC | Unloader system and method for a compressor |
8485789, | May 18 2007 | EMERSON CLIMATE TECHNOLOGIES, INC | Capacity modulated scroll compressor system and method |
8807961, | Jul 23 2007 | Emerson Climate Technologies, Inc. | Capacity modulation system for compressor and method |
8814537, | Sep 30 2011 | Emerson Climate Technologies, Inc. | Direct-suction compressor |
9322405, | Oct 29 2013 | Emerson Climate Technologies, Inc. | Rotary compressor with vapor injection system |
9366462, | Sep 13 2012 | EMERSON CLIMATE TECHNOLOGIES, INC | Compressor assembly with directed suction |
9897088, | Jan 21 2013 | COPELAND CLIMATE TECHNOLOGIES SUZHOU CO LTD | Scroll compressor with back pressure chamber having leakage channel |
ER5358, | |||
RE44636, | Sep 29 1997 | Emerson Climate Technologies, Inc. | Compressor capacity modulation |
Patent | Priority | Assignee | Title |
3653783, | |||
4361417, | Jun 12 1979 | Hitachi, Ltd.; Tokico Ltd. | Oil-cooled compressor |
4407639, | Jan 29 1981 | Matsushita Electric Industrial Co., Ltd. | Compressor |
4588359, | Dec 24 1984 | Vilter Manufacturing Corporation | Compressor capacity control apparatus |
4651535, | Aug 08 1984 | Pulse controlled solenoid valve | |
4669272, | Jun 27 1985 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Variable displacement refrigerant compressor of variable angle wobble plate type |
4685309, | Nov 01 1982 | Emerson Electric Co. | Pulse controlled expansion valve for multiple evaporators and method of controlling same |
4697431, | Aug 08 1984 | Refrigeration system having periodic flush cycles | |
4715792, | Apr 05 1985 | Nippondenso Co., Ltd. | Variable capacity vane type compressor |
4723895, | Feb 04 1983 | Hitachi, Ltd. | Method of and apparatus for effecting volume control of compressor |
4726740, | Aug 16 1984 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Rotary variable-delivery compressor |
4789025, | Nov 25 1987 | Carrier Corporation | Control apparatus for refrigerated cargo container |
4856291, | Dec 28 1987 | ZEZEL CORPORATION | Air conditioning system for automotive vehicles |
4875341, | Nov 25 1987 | Carrier Corporation | Control apparatus for refrigerated cargo container |
4892466, | May 20 1987 | MATSUSHITA ELECTRIC INDUSTRIAL CO , LTD | Variable capacity compressor |
4974427, | Oct 17 1989 | Copeland Corporation | Compressor system with demand cooling |
5015155, | Mar 26 1990 | Copeland Corporation | Motor cover assembly and method |
5018366, | Feb 05 1988 | KABUSHIKI KAISHA TOYODA JIDOSHOKKI SEISAKUSHO, 1, TOYODA-CHO 2-CHOME, KARIYA-SHI, AICHI-KEN, JAPAN | Control circuit unit for a variable capacity compressor incorporating a solenoid-operated capacity control valve |
5035119, | Aug 08 1984 | Apparatus for monitoring solenoid expansion valve flow rates | |
5059098, | Feb 02 1989 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | Apparatus for varying capacity of scroll type compressor |
5163301, | Sep 09 1991 | Carrier Corporation | Low capacity control for refrigerated container unit |
5190446, | Sep 29 1988 | Artemis Intelligent Power Ltd | Pump control method and poppet valve therefor |
5226472, | Nov 15 1991 | Lab-Line Instruments, Inc. | Modulated temperature control for environmental chamber |
5228301, | Jul 27 1992 | Westinghouse Electric Corporation | Methods and apparatus for operating a refrigeration system |
5247989, | Nov 15 1991 | Lab-Line Instruments, Inc. | Modulated temperature control for environmental chamber |
5253482, | Jun 26 1992 | Heat pump control system | |
5388968, | Jan 12 1994 | Ingersoll-Rand Company | Compressor inlet valve |
5415008, | Mar 03 1994 | General Electric Company | Refrigerant flow rate control based on suction line temperature |
5425246, | Mar 03 1994 | General Electric Company | Refrigerant flow rate control based on evaporator dryness |
5431026, | Mar 03 1994 | General Electric Company | Refrigerant flow rate control based on liquid level in dual evaporator two-stage refrigeration cycles |
5463876, | Apr 04 1994 | General Electric Company | Control system for refrigerant metering solenoid valve |
5546756, | Feb 08 1995 | Eaton Corporation | Controlling an electrically actuated refrigerant expansion valve |
5572879, | May 25 1995 | Thermo King Corporation | Methods of operating a refrigeration unit in predetermined high and low ambient temperatures |
5611674, | Jun 07 1995 | Copeland Corporation | Capacity modulated scroll machine |
5613841, | Jun 07 1995 | Copeland Corporation | Capacity modulated scroll machine |
5634350, | Sep 20 1994 | HAMILTON SUNDSTRAND ITALIA S R L | Refrigeration system |
5741120, | Jun 07 1995 | Copeland Corporation | Capacity modulated scroll machine |
6047556, | Dec 08 1997 | Carrier Corporation | Pulsed flow for capacity control |
6047557, | Jun 07 1995 | Copeland Corporation | Adaptive control for a refrigeration system using pulse width modulated duty cycle scroll compressor |
6086335, | Jun 07 1995 | Copeland Corporation | Capacity modulated scroll machine having one or more pin members movably disposed for restricting the radius of the orbiting scroll member |
6393852, | Jun 07 1995 | Copeland Corporation | Adaptive control for a refrigeration system using pulse width modulated duty cycle scroll compressor |
6408635, | Jun 07 1995 | Copeland Corporation | Adaptive control for a refrigeration system using pulse width modulated duty cycle scroll compressor |
6438974, | Jun 07 1995 | Copeland Corporation | Adaptive control for a refrigeration system using pulse width modulated duty cycle scroll compressor |
6449972, | Jun 07 1995 | Copeland Corporation | Adaptive control for a refrigeration system using pulse width modulated duty cycle scroll compressor |
6467280, | Jun 07 1995 | Copeland Corporation | Adaptive control for a refrigeration system using pulse width modulated duty cycle scroll compressor |
6499305, | Jun 07 1995 | Copeland Corporation | Adaptive control for a refrigeration system using pulse width modulated duty cycle scroll compressor |
6662578, | Jun 07 1995 | Copeland Corporation | Refrigeration system and method for controlling defrost |
6662583, | Jun 07 1995 | Copeland Corporation | Adaptive control for a cooling system |
6679072, | Jun 07 1995 | Copeland Corporation | Diagnostic system and method for a cooling system |
DE3422398, | |||
DE764179, | |||
EP482592, | |||
GB2116635, | |||
JP57162988, | |||
JP57204381, | |||
JP58214644, | |||
JP59145392, | |||
JP61107989, | |||
JP61138490, | |||
JP62003190, | |||
JP62003191, | |||
JP62125262, | |||
JP62125263, | |||
JP6229779, | |||
JP8284842, |
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