Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D25/00—Pumping installations or systems
  • F04D25/16—Combinations of two or more pumps ; Producing two or more separate gas flows
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
  • F04D27/02—Surge control
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/07—Details of compressors or related parts
  • F25B2400/075—Details of compressors or related parts with parallel compressors
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/8593—Systems
  • Y10T137/85978—With pump
  • Y10T137/86131—Plural
  • Y10T137/86163—Parallel

Definitions

• the present invention relates to compressors. More specifically, the present invention is concerned with a dynamically controlled compressor system and method.
• centrifugal compressors have an operating envelope, referred to as the compressor map, which is limited by a condition called choke and another condition called surge.
• centrifugal compressors pump gas when operating within the surge and choke points. If a centrifugal compressor is left operating in a surge condition for any length of time, impellors thereof can overheat and damage the whole machine. Compressor manufacturers go to length at trying to protect the compressor from operating in these damaging conditions with a variety of surge detection devices, which, when they detect a surge, shut the machine down to prevent damage.
• centrifugal compressors In order to conserve energy, some more recent centrifugal compressors have added speed control to increase its operating range and in these cases the compressors control system has become dynamic. While up until this point, the compressors were either on or off, they have thus become more intelligent and the dynamic nature of the controls causes the compressors to react to changes in the condition. In a most recent version now available on the marketplace, by the present applicant, the centrifugal compressors may have totally dynamic controls and continually optimizes their speed and the positions of their inlet guide vanes to maximize their efficiency.
• centrifugal compressors have been mainly single compressor systems, and in more recent years, when two compressors have been applied to the one machine, have run in parallel and the loading and unloading has been through the use of the (IGV) alone and have been controlled from the one controller and therefore load and unload at the same rate and at the same time.
• compressors have a compressor map programmed into a control unit thereof, to adjust their speed and when necessary also operate their inlet guide vanes in order to maximize their performance.
• Such dynamic control system provides that the compressors adapt their operating parameters as the conditions in the system change and as the load in the system varies.
• FIG. 1 illustrating a first compressor comp 1 and a second compressor comp 2 in parallel between a low pressure side (suction line) and a high pressure side (discharge line), operating conditions of the first compressor may be directly effected by a change in pumping capacity of the second compressor. This may occur for example when one the compressors, a condenser or an evaporator, are not adequately sized and a pipe work to and from the compressors is not connected in an independent fashion, or in the case when multiple compressors are connected in parallel and the point of interconnection between the compressors is to a common point or a common pipe and the capacity at the connecting point is not adequate to compensate for the changes in the first compressor and therefore has an immediate effect on the second compressor.
• a multiple compressor system comprising at least a first and a second compressors in parallel between a low pressure side and a high pressure side; at least one inertia vessel connected to one of suction lines and discharge lines of the at least first and second compressors; wherein the at least one inertia vessel acts as a means of dampening changes of operation condition of the at least first and second compressors.
• a method for controlling a compressor system including at least two compressors arranged in parallel between a low pressure side and a high pressure side, comprising the step of connecting at least one inertia vessel to at least one of: a suction line and: a discharge line of at least one of the at least two compressors.
• Figure 1 labelled as Prior Art, illustrates a piping configuration of multiple compressors piped up in parallel, as known in the art
• Figure 2 illustrates a system according to an embodiment of the present invention
• Figure 3 illustrates a system according to an other embodiment of the present invention.
• Figure 4 illustrates a system according to a further embodiment of the present invention
• Figures 5 illustrate alternatives to the embodiment of Figure
• Figure 6 illustrates a system according to still a further embodiment of the present invention.
• Figure 7 illustrates an alternative to the embodiment of Figure 6; and [0020]
• Figure 8 illustrates a system comprising multiple compressors piped in parallel to and from a common vessel, i.e. condenser and evaporator, which most likely does not require inertia tanks.
• Such a dynamic control system may be applied to conventional system using other types of positive displacement compressors such as reciprocating, scroll or screw compressors for example.
• the compressor may thus respond as the load demand changes in the process in which it is being applied, such as a manufacturing process.
• the present invention provides an adequately sized vessel or tank in either or both the suction line or the discharge line of multiple compressors, in such a fashion that if the conditions of the first compressor change, it does not have an immediate effect on the other compressors, the vessel acting as a means of dampening the change.
• Figure 2 illustrates a parallel piping system comprising a header arrangement to reduce the impact of a first compressor changes in operation on a second compressor: a common low pressure tank 12 is connected to the suction line and a high pressure tank 14 is connected to the discharge line of the compressors Comp 1 and Comp 2.
• an expansion tank is installed in the discharge 14a, 14b and in the suction 12a, 12b lines of each compressors Comp 1 and Comp2 to reduce the impact of the change in the first compressor operation on the second compressor.
• Figure 4 illustrates a system of hermetic or semi-hermetic compressors wherein a compressor housing, such as in a hermetic or semi- hermetic compressor, is provided, which is adequately sized to act as an inertia tank thus eliminating the need for external inertia tanks.
• Figures 5 illustrate a system comprising two compressors sharing a same housing adequately sized to act as an inertia tank thus eliminating the need for an external inertia tank.
• This type of system may have one or more exit and entry ports (see Figures 5a and 5b).
• Figure 6 illustrates an alternative embodiment where a low and high pressure inertia tanks are provided, these inertia tanks being modular in design and connected by flanged connections or connections as provided by Victualic Inc. for example, the inlet and outlet pipes being connected at either end.
• the inlet and outlet pipes to the inertia tanks may be connected into any part of the inertia tanks.
• the inlet and outlet connections may be installed into the middle of the stack in order to balance the distribution of the gas and reduce the size of the individual inertia tanks.
• refrigerant may enter and exit the system from any of at least one ports.
• the present invention may be used in applications where multiple dynamically controlled compressors are used to replace one large compressor and where the suction and discharge lines have to be connected to a heat exchanger through either or both the one entry and one exit points.
• An example of this would be a water chiller where there is one entry to the condenser and one exit from the evaporator. If the compressor only required one compressor, then there would be no problem, however where two or more compressors are needed to obtain a required capacity, then simply piping the compressors as is usually done in the art is inefficient. The connecting point of the pipe work needs to be of adequate size as to not have an immediate effect on the other compressors operating in the system.
• the present invention may be applied to systems comprising more than two compressors.
• the systems of Figures 2-8 may be expanded by adding additional compressors either when the systems are first installed or at a later date as required.
• Each of the systems may also have the capability to be piped up with single or multiple suction and discharge pipes.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=35785869

Family Applications (1)

Country Status (9)

Families Citing this family (4)

Citations (4)

Family Cites Families (14)

• 2005
  • 2005-07-21 CA CA 2574879 patent/CA2574879C/en not_active Expired - Fee Related
  • 2005-07-21 JP JP2007522883A patent/JP2008507659A/ja active Pending
  • 2005-07-21 KR KR1020077004091A patent/KR20070045266A/ko not_active Application Discontinuation
  • 2005-07-21 BR BRPI0513578-8A patent/BRPI0513578A/pt not_active IP Right Cessation
  • 2005-07-21 US US11/658,811 patent/US20080210317A1/en not_active Abandoned
  • 2005-07-21 WO PCT/CA2005/001149 patent/WO2006010251A1/en active Application Filing
  • 2005-07-21 CN CNA2005800255936A patent/CN101002025A/zh active Pending
  • 2005-07-21 EP EP05764273A patent/EP1781949A4/en not_active Withdrawn
  • 2005-07-21 AU AU2005266792A patent/AU2005266792A1/en not_active Abandoned

Patent Citations (4)

Non-Patent Citations (1)

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