US20110314847A1 - Dual duty compression machine - Google Patents
Dual duty compression machine Download PDFInfo
- Publication number
- US20110314847A1 US20110314847A1 US13/255,198 US201013255198A US2011314847A1 US 20110314847 A1 US20110314847 A1 US 20110314847A1 US 201013255198 A US201013255198 A US 201013255198A US 2011314847 A1 US2011314847 A1 US 2011314847A1
- Authority
- US
- United States
- Prior art keywords
- compressor
- compression machine
- mode
- water
- duty
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 230000006835 compression Effects 0.000 title claims abstract description 101
- 238000007906 compression Methods 0.000 title claims abstract description 101
- 230000009977 dual effect Effects 0.000 title claims description 5
- 239000003507 refrigerant Substances 0.000 claims abstract description 96
- 238000001816 cooling Methods 0.000 claims abstract description 40
- 238000010438 heat treatment Methods 0.000 claims abstract description 31
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 45
- 238000000034 method Methods 0.000 claims description 14
- 238000004891 communication Methods 0.000 claims description 10
- 239000000498 cooling water Substances 0.000 claims description 3
- 239000008236 heating water Substances 0.000 claims description 3
- 239000012267 brine Substances 0.000 abstract description 14
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 abstract description 14
- 239000007788 liquid Substances 0.000 description 17
- 238000004378 air conditioning Methods 0.000 description 7
- 239000007858 starting material Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 5
- 239000013529 heat transfer fluid Substances 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
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
- F04D27/02—Surge control
- F04D27/0269—Surge control by changing flow path between different stages or between a plurality of compressors; load distribution between compressors
Definitions
- This invention relates generally to compression machines for building cooling and heating application or ice thermal storage application and, more particularly, to a compression machine having dual compressors, one compressor dedicated for water chilling and the other compressor dedicated for water heating or ice thermal storage.
- a common type of compression chiller includes a tube-in-shell heat exchanger that functions as a refrigerant vapor condenser, a tube-in-shell heat exchanger that functions as a refrigerant liquid evaporator, and a centrifugal compressor that has an inlet in refrigerant flow communication with the evaporator and an outlet in refrigerant flow communication with the condenser.
- a centrifugal compressor that has an inlet in refrigerant flow communication with the evaporator and an outlet in refrigerant flow communication with the condenser.
- water is passed through the heat exchange tubes in heat exchange relationship with hot refrigerant vapor discharged from the compressor into the shell of the condenser and flowing over the heat exchange tubes.
- the refrigerant vapor is condensed and the water flowing through the heat exchange tubes is heated.
- the condensed liquid refrigerant is passed through an expansion device and thereby expanded to form a lower pressure, lower temperature refrigerant liquid/vapor mixture.
- the refrigerant liquid/vapor mixture is delivered into the shell of the evaporator and dispersed to flow over the heat exchange tubes therein.
- water passing through the heat exchange tubes is cooled and the refrigerant liquid/vapor mixture is heated and the liquid refrigerant evaporated.
- the refrigerant vapor exits the shell of the evaporator and passes back the inlet of the compressor, thereby completing the refrigerant flow circuit.
- Compression machines of this type may also be used for heating water in the winter for building space heating purposes, in addition to cooling water in the summer for building air conditioning purposes.
- designing the compression machine for dual purposes i.e. both water-cooling in the summer and water heating in winter is complicated due to the quite different temperatures of the water supplied to the compression machine and differing temperature required to be supplied to the building for cooling/heating.
- the lift required for water heating in the winter may be nearly twice the lift required for water-cooling in the summer. Consequently, in compression machines designed with a single compressor, the compressor must be selected to provide sufficient capacity to meet the winter heating lift requirement, and then be operated at a substantially reduced capacity during the summer cooling season to match the reduced summer cooling lift requirement.
- compressors operating at a substantially reduced capacity in particular centrifugal compressors operating at a substantially reduced capacity, suffer a significant reduction in energy efficiency, leading to a waste of energy and increased power consumption costs.
- compression machines of this type typically employ a single compressor
- compression machines employing two compressors are also known.
- a compression chiller using two individual centrifugal compressors arranged in series is disclosed in U.S. Pat. No. 5,875,637.
- the first compressor receives through its inlet low pressure refrigerant vapor from the evaporator and discharges refrigerant vapor at an intermediate pressure to the inlet of the second compressor.
- the refrigerant vapor is further compressed in the second compressor and discharged to the condenser at a relatively higher discharge pressure.
- the compression machine includes an evaporator, a condenser divided into two separate chambers, and two separate centrifugal compressors are in parallel.
- Each compressor receives as its input refrigerant vapor from the evaporator. However, each compressor discharges compressed refrigerant vapor into a respective separate one of the chambers of the condenser.
- a compression machine provided for selective operation in one of a first duty mode and a second duty mode.
- the compression machine includes: a refrigerant condenser, an expansion device, a refrigerant evaporator, and a compression device disposed in a serial refrigerant flow relationship.
- the compression device includes a first compressor and a second compressor, each of which is arranged to receive lower pressure refrigerant vapor from the evaporator and to deliver higher pressure vapor to the condenser independently of the other.
- the first compressor is selected for optimum operation of the compression machine in the first duty mode and the second compressor is selected for optimum operation of the compression machine in the second duty mode.
- the first duty mode has a first lift requirement and the second duty mode has a second lift requirement that is greater than the first lift requirement.
- the first duty mode may be a water-cooling mode and the second duty mode may be one of a water-heating mode or a brine cooling mode.
- a controller may be provided in operative association with each of the first compressor and the second compressor, selectively operates the first compressor when operating the compression machine in a water-cooling mode and selectively operates the second compressor when operating the compression machine in a water-heating mode.
- the controller directs electric power to a first drive motor for driving the first compressor when operating the compression machine in a water-cooling mode and directs electric power to a second drive motor for driving the second compressor when operating the compression machine in a water-heating mode.
- each of the first compressor and the second compressor comprises a centrifugal compressor.
- a method for operating a compression machine for selectively cooling water or heating water, the compression machine having a condenser and an evaporator in refrigerant flow communication with the condenser, a first compressor for receiving refrigerant vapor from the evaporator and delivering refrigerant vapor to the condenser, and a second compressor for receiving refrigerant vapor from the evaporator and delivering refrigerant vapor to the condenser.
- the method includes the steps of: selectively operating the compression machine in one of a water cooling mode or a water heating mode; operating the first compressor when operating the compression machine in a water cooling mode; and operating the second compressor when operating the compression machine in a water heating mode.
- a method for designing a compression machine for selective operation in one of a first duty mode or a second duty mode, the compression machine having a condenser and an evaporator in refrigerant flow communication with the condenser, a first compressor for receiving refrigerant vapor from the evaporator and delivering refrigerant vapor to the condenser, and a second compressor for receiving refrigerant vapor from the evaporator and delivering refrigerant vapor to the condenser.
- the method includes the steps of: selecting the first compressor to perform optimally in the first duty mode, and selecting the second compressor to perform optimally in the second duty mode.
- the first duty mode has a first lift requirement and the second duty mode has a second lift requirement that is greater than the first lift requirement.
- the step of selecting the first compressor to perform optimally in the first duty mode comprises selecting the first compressor to perform optimally in a water-cooling mode; and the step of selecting the second compressor to perform optimally in the second duty mode comprises selecting the second compressor to perform optimally in one of a water-heating mode or a brine-cooling mode.
- FIG. 1 is perspective view of an exemplary embodiment of a compression machine in accordance with the invention
- FIG. 2 is a schematic diagram depicting the compression machine of FIG. 1 .
- the compression machine 10 includes a refrigerant condenser 20 , an expansion device 25 , a refrigerant evaporator 30 , and a compression device disposed in a serial refrigerant flow relationship.
- the compression device includes a first compressor 40 and a second compressor 50 , each of which is arranged to receive lower pressure refrigerant vapor from the evaporator 30 and to deliver higher pressure refrigerant vapor to the condenser 20 independently of the other.
- Separate drive motors 42 , 52 are provided in operative association with the first compressor 40 and the second compressor 50 , respectively.
- the first drive motor 42 drives only the first compressor 40 .
- the second drive motor 52 drives only the second compressor 50 .
- each of the first compressor 40 and the second compressor 50 comprises a centrifugal compressor.
- the condenser 20 is a liquid-cooled condenser and may any one of various conventional designs.
- the condenser 20 may be a tube-in-shell condenser, wherein a heat transfer fluid, most commonly, and in the application described herein, water, is passed through a multiple-tube heat exchanger (not shown) housed in a closed shell into which is introduced high pressure, high temperature refrigerant vapor discharged from the compression device.
- the high temperature refrigerant passes over the exterior of the tubes of the heat exchanger in heat exchange relationship with the water passing through the tubes of the heat exchanger, whereby the refrigerant vapor is cooled and condensed to a refrigerant liquid and the water is heated.
- the high pressure, condensed refrigerant liquid passes from the condenser 20 to the evaporator 30 through a refrigerant passage 11 in which is disposed an expansion device 25 .
- the refrigerant liquid expands to a lower pressure and a lower temperature to form a refrigerant vapor or a saturated mixture of refrigerant liquid and refrigerant vapor at the lower pressure and the lower temperature.
- the lower pressure, lower temperature vapor or liquid/vapor mixture is delivered via the passage 11 to and introduced into the shell of the evaporator 30 .
- the evaporator 30 also may any one of various conventional designs.
- the evaporator 30 may be a tube-in-shell evaporator, wherein a heat transfer fluid, most commonly, and in the application described herein, water or a chemical salt solution (brine), is passed through a multiple-tube heat exchanger (not shown) housed in a closed shell into which is introduced the lower pressure, lower temperature refrigerant liquid in traversing the expansion device 25 .
- the lower temperature refrigerant liquid collects in the shell immersing the tubes of the heat exchanger.
- the water or brine passing through the tubes passes in heat exchange relationship with the liquid refrigerant in which the tubes are immersed, whereby the refrigerant liquid is heated and evaporated to a refrigerant vapor and the water or brine is cooled.
- first compressor 40 and the second compressor 50 are each arranged in the refrigerant flow circuit between the evaporator 30 and the condenser 20 .
- a refrigerant line 47 has an outlet opening into the shell of the condenser 20 and an inlet in communication with the discharge outlet of the first compressor 40 whereby the first compressor 40 discharges higher pressure, hot refrigerant vapor into the condenser 20 .
- a refrigerant line 57 has an outlet opening into the shell of the condenser 20 and an inlet in communication with the discharge outlet of the second compressor 50 whereby the second compressor 50 discharges higher pressure, hot refrigerant vapor into the condenser 30 .
- a refrigerant line 43 has an inlet opening into the shell of the evaporator 30 and an outlet in communication with the suction inlet of the first compressor 40 whereby the first compressor 40 receives lower pressure refrigerant vapor from the evaporator 30 .
- a refrigerant line 53 has an inlet opening into the shell of the evaporator 30 and an outlet in communication with the suction inlet of the second compressor 50 whereby the first compressor 50 receives lower pressure refrigerant vapor from the evaporator 30 .
- a first flow shut-off valve 45 is interdisposed in refrigerant line 43 upstream with respect to refrigerant flow of the suction inlet to the first compressor 40 .
- a second flow shut-off valve 55 is interdisposed in refrigerant line 53 upstream with respect to refrigerant flow of the suction inlet to the second compressor 50 .
- the compression machine 10 may also include a control system 80 for selectively operating the first compressor 40 and the second compressor 50 .
- the control system may include a first controller 80 - 1 that is operatively associated with the first compressor 40 and its drive motor 42 and a second controller 80 - 2 that is operatively associated with the second compressor 50 and its drive motor 52 , and a motor starter 82 that is capable of selectively starting either the first compressor 40 or the second compressor 50 as directed.
- the control system may also include a master controller (not shown) that selectively independently commands the first and second controllers 80 - 1 , 80 - 2 .
- the control system 80 associated with the compression machine 10 may include a single controller for controlling the first and second compressors 40 , 50 respectively.
- control system 80 may be configured to operate the compression machine 10 in a water-cooling mode during the summer cooling season to supply chilled water to an air conditioning system (not shown) of a building associated with the compression machine 10 .
- the control system 80 operates the compression machine 10 in a water-heating mode during the winter heating season to provide hot water to the air conditioning system of a building associated with the compression machine 10 .
- the compression machine 10 may need to supply chilled water at a temperature in the vicinity of about 7° C. (about 45° F.) during the summer cooling system, and need to supply hot water at a temperature in the vicinity of about 50° C. (about 122° F.) during the winter heating season.
- the lift requirement associated with water-cooling duty would be less than the lift requirement associated with water-heating duty.
- control system 80 may be configured during the summer to operate the compression machine 10 in a brine-cooling mode to supply chilled brine to an air conditioning system (not shown) of a building associated with the compression machine 10 during the hours of the day when the building is occupied and to supply chilled brine to an ice-storage system (not shown) to make ice during the hours of the night when the building occupancy is lower, such as typically at night. Chilling brine for the air-conditioning duty would have a lower lift requirement than chilling brine for ice-making duty.
- the compression machine 10 is designed for selective operation in one of a first duty mode and a second duty mode.
- the first compressor 40 is selected for optimal operation of the compression machine 10 in the first duty mode, for example a water-cooling mode
- the second compressor 50 is selected for optimal operation of the compression machine 10 in the second duty mode, for example a water-heating mode or a brine cooling mode.
- first compressor 40 is selected for optimal operation of the compression machine for providing chilled water passing from the refrigerant evaporator at a temperature in the range of from about 2° C. to about 12° C. (about 35° F. to about 54° F.).
- second compressor 50 is selected for optimal operation of the compression machine for providing heated water passing from the refrigerant condenser at a temperature in the range of from about 40° C. to about 60° C. (about 104° F. to about 140° F.). In an embodiment, the second compressor 50 is selected for optimal operation of the compression machine 10 for providing chilled brine to an ice thermal storage system (not shown) for use in making ice.
- the controller 80 closes the flow shut-off valve 55 in refrigerant line 53 thereby isolating the second compressor 50 from the refrigerant circuit, supplies electric power to the starter 82 , and commands the starter 82 to activate the first drive motor 42 for driving only the first compressor 40 .
- the controller 80 closes the flow shut-off valve 45 in refrigerant line 43 thereby isolating the first compressor 40 from the refrigerant circuit, supplies electric power to the starter 82 , and commands the starter 82 to activate the second drive motor 52 for driving only the second compressor 50 .
- the first compressor 40 when operating the compression machine 10 in the first duty mode, the first compressor 40 is operated and the second compressor 50 is shutdown and isolated from the refrigerant circuit. Conversely, when operating he compression machine 10 in the second duty mode, the second compression 50 is operated and the first compressor 40 is shut down and isolated from the refrigerant circuit.
- the compression machine 10 is designed for optimal energy efficiency in both the water-cooling mode and the water-heating or brine cooling mode by selecting as the first compressor 40 a first compressor selected to perform optimally in a water cooling mode only, and by selecting as the second compressor 50 a second compressor selected to perform optimally in one of a water heating mode or brine cooling mode.
- the second compressor 50 for optimal capacity and efficiency in the water heating mode or ice storage mode, wherein the lift required could be as much as about twice the lift required in the water cooling mode
- the first compressor 40 may be selected for optimal efficiency and performance to meet the lower lift demands
- the second compressor 50 may be selected for optimal efficiency and performance to meet the higher lift demands.
- water for delivery to the evaporator 30 may be drawn from a outside water source at a temperature of about 7° C. (about 45° F.) and the hot water leaving the condenser 20 to meet space heating demand may need to be at a temperature of about 50° C. (about 122° F.), while in the summer, water for delivery to the condenser 20 may be from the outdoor water source at a temperature of about 32° C. (about 90° F.) and the chilled water leaving the evaporator 30 to meet air conditioning demand may need to be at a temperature of about 7° C. (about 45° F.).
- the designer would necessarily need to size the compressor to meet the maximum lift requirement and compression capacity demand associated with the second duty mode and simply expect lower than optimal efficiency performance during operation in the first duty mode.
- the compression machine 10 of the invention provides for optimal performance in both the lower lift requirement first duty mode and the higher lift requirement second duty mode.
- the first compressor 40 and the second compressor 50 are designed to not operate at the same time.
- the first compressor 40 is selected for operation in, and is only operated, when the compression machine 10 operates in the water-cooling mode
- the second compressor 50 is selected for operation in, and is only operated, when the compression machine 10 operates in the water-heating mode.
- only one motor starter 82 In this embodiment, only one motor starter 82 .
- the second compressor 50 which is the compressor selected for operation in the second duty mode, that is the duty mode having the higher lift requirement, is positioned opposite the end at which the water enters the evaporator.
- the second compressor 50 should be positioned as far as practical from the water inlet end to the condenser to avoid liquid carry-over inside the evaporator, which is driven by the pressure difference between the condenser and the evaporator.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Compressor (AREA)
Abstract
Description
- Reference is made to and this application claims priority from and the benefit of U.S. Provisional Application Ser. No. 61/167,978, filed Apr. 9, 2009, entitled “DUAL DUTY COMPRESSION MACHINE”, which application is incorporated herein in its entirety by reference.
- This invention relates generally to compression machines for building cooling and heating application or ice thermal storage application and, more particularly, to a compression machine having dual compressors, one compressor dedicated for water chilling and the other compressor dedicated for water heating or ice thermal storage.
- Compression machines are well known for use in providing chilled water for use in air conditioning systems for buildings, especially large commercial buildings. A common type of compression chiller includes a tube-in-shell heat exchanger that functions as a refrigerant vapor condenser, a tube-in-shell heat exchanger that functions as a refrigerant liquid evaporator, and a centrifugal compressor that has an inlet in refrigerant flow communication with the evaporator and an outlet in refrigerant flow communication with the condenser. In the condenser, water is passed through the heat exchange tubes in heat exchange relationship with hot refrigerant vapor discharged from the compressor into the shell of the condenser and flowing over the heat exchange tubes. In doing so, the refrigerant vapor is condensed and the water flowing through the heat exchange tubes is heated. The condensed liquid refrigerant is passed through an expansion device and thereby expanded to form a lower pressure, lower temperature refrigerant liquid/vapor mixture. The refrigerant liquid/vapor mixture is delivered into the shell of the evaporator and dispersed to flow over the heat exchange tubes therein. In the evaporator, water passing through the heat exchange tubes is cooled and the refrigerant liquid/vapor mixture is heated and the liquid refrigerant evaporated. The refrigerant vapor exits the shell of the evaporator and passes back the inlet of the compressor, thereby completing the refrigerant flow circuit.
- Compression machines of this type may also be used for heating water in the winter for building space heating purposes, in addition to cooling water in the summer for building air conditioning purposes. However, designing the compression machine for dual purposes, i.e. both water-cooling in the summer and water heating in winter is complicated due to the quite different temperatures of the water supplied to the compression machine and differing temperature required to be supplied to the building for cooling/heating. The lift required for water heating in the winter may be nearly twice the lift required for water-cooling in the summer. Consequently, in compression machines designed with a single compressor, the compressor must be selected to provide sufficient capacity to meet the winter heating lift requirement, and then be operated at a substantially reduced capacity during the summer cooling season to match the reduced summer cooling lift requirement. Unfortunately, compressors operating at a substantially reduced capacity, in particular centrifugal compressors operating at a substantially reduced capacity, suffer a significant reduction in energy efficiency, leading to a waste of energy and increased power consumption costs.
- Although compression machines of this type typically employ a single compressor, compression machines employing two compressors are also known. For example, a compression chiller using two individual centrifugal compressors arranged in series is disclosed in U.S. Pat. No. 5,875,637. As disclosed therein, the first compressor receives through its inlet low pressure refrigerant vapor from the evaporator and discharges refrigerant vapor at an intermediate pressure to the inlet of the second compressor. The refrigerant vapor is further compressed in the second compressor and discharged to the condenser at a relatively higher discharge pressure.
- Another example of a compression machine having two centrifugal compressors is disclosed in U.S. Pat. No. 3,859,820. As disclosed therein, the compression machine includes an evaporator, a condenser divided into two separate chambers, and two separate centrifugal compressors are in parallel. Each compressor receives as its input refrigerant vapor from the evaporator. However, each compressor discharges compressed refrigerant vapor into a respective separate one of the chambers of the condenser.
- In such two-compressor compression machines, increased capacity may be achieved relative to single compressor compression machines as both compressors, whether disposed in a series arrangement or a parallel arrangement, are operated simultaneously. In the series arrangement of the two centrifugal compressors, the increased capacity is attainable because the individual rises in refrigerant pressure developed in the separate compressors is additive. In the parallel arrangement of the two centrifugal compressors, the increased capacity is attainable because the overall refrigerant throughput is the sum of the refrigerant flows through the two centrifugal compressors. However, the increased capacity comes at a price, as each compressor must have its own drive motor, starter and controls. Additionally, the overall system controls are necessarily more complicated.
- In an aspect of the invention, a compression machine provided for selective operation in one of a first duty mode and a second duty mode. The compression machine includes: a refrigerant condenser, an expansion device, a refrigerant evaporator, and a compression device disposed in a serial refrigerant flow relationship. The compression device includes a first compressor and a second compressor, each of which is arranged to receive lower pressure refrigerant vapor from the evaporator and to deliver higher pressure vapor to the condenser independently of the other. The first compressor is selected for optimum operation of the compression machine in the first duty mode and the second compressor is selected for optimum operation of the compression machine in the second duty mode. In an embodiment, the first duty mode has a first lift requirement and the second duty mode has a second lift requirement that is greater than the first lift requirement. In an embodiment, the first duty mode may be a water-cooling mode and the second duty mode may be one of a water-heating mode or a brine cooling mode.
- A controller may be provided in operative association with each of the first compressor and the second compressor, selectively operates the first compressor when operating the compression machine in a water-cooling mode and selectively operates the second compressor when operating the compression machine in a water-heating mode. The controller directs electric power to a first drive motor for driving the first compressor when operating the compression machine in a water-cooling mode and directs electric power to a second drive motor for driving the second compressor when operating the compression machine in a water-heating mode. In an embodiment, each of the first compressor and the second compressor comprises a centrifugal compressor.
- In an aspect of the invention, a method is provided for operating a compression machine for selectively cooling water or heating water, the compression machine having a condenser and an evaporator in refrigerant flow communication with the condenser, a first compressor for receiving refrigerant vapor from the evaporator and delivering refrigerant vapor to the condenser, and a second compressor for receiving refrigerant vapor from the evaporator and delivering refrigerant vapor to the condenser. The method includes the steps of: selectively operating the compression machine in one of a water cooling mode or a water heating mode; operating the first compressor when operating the compression machine in a water cooling mode; and operating the second compressor when operating the compression machine in a water heating mode.
- In an aspect of the invention, a method is provided for designing a compression machine for selective operation in one of a first duty mode or a second duty mode, the compression machine having a condenser and an evaporator in refrigerant flow communication with the condenser, a first compressor for receiving refrigerant vapor from the evaporator and delivering refrigerant vapor to the condenser, and a second compressor for receiving refrigerant vapor from the evaporator and delivering refrigerant vapor to the condenser. The method includes the steps of: selecting the first compressor to perform optimally in the first duty mode, and selecting the second compressor to perform optimally in the second duty mode. In an embodiment, the first duty mode has a first lift requirement and the second duty mode has a second lift requirement that is greater than the first lift requirement. In an embodiment of the method, the step of selecting the first compressor to perform optimally in the first duty mode comprises selecting the first compressor to perform optimally in a water-cooling mode; and the step of selecting the second compressor to perform optimally in the second duty mode comprises selecting the second compressor to perform optimally in one of a water-heating mode or a brine-cooling mode.
- For a further understanding of the disclosure, reference will be made to the following detailed description which is to be read in connection with the accompanying drawings, where:
-
FIG. 1 is perspective view of an exemplary embodiment of a compression machine in accordance with the invention; -
FIG. 2 is a schematic diagram depicting the compression machine ofFIG. 1 . - Referring now to the drawing, there is depicted therein an exemplary embodiment of a compression machine, designated generally by the
reference numeral 10. Thecompression machine 10 includes arefrigerant condenser 20, anexpansion device 25, arefrigerant evaporator 30, and a compression device disposed in a serial refrigerant flow relationship. The compression device includes afirst compressor 40 and asecond compressor 50, each of which is arranged to receive lower pressure refrigerant vapor from theevaporator 30 and to deliver higher pressure refrigerant vapor to thecondenser 20 independently of the other.Separate drive motors first compressor 40 and thesecond compressor 50, respectively. Thefirst drive motor 42 drives only thefirst compressor 40. Thesecond drive motor 52 drives only thesecond compressor 50. In the depicted exemplary embodiment, each of thefirst compressor 40 and thesecond compressor 50 comprises a centrifugal compressor. - The
condenser 20 is a liquid-cooled condenser and may any one of various conventional designs. For example, for purposes of illustration, but not limitation, thecondenser 20 may be a tube-in-shell condenser, wherein a heat transfer fluid, most commonly, and in the application described herein, water, is passed through a multiple-tube heat exchanger (not shown) housed in a closed shell into which is introduced high pressure, high temperature refrigerant vapor discharged from the compression device. The high temperature refrigerant passes over the exterior of the tubes of the heat exchanger in heat exchange relationship with the water passing through the tubes of the heat exchanger, whereby the refrigerant vapor is cooled and condensed to a refrigerant liquid and the water is heated. - The high pressure, condensed refrigerant liquid passes from the
condenser 20 to theevaporator 30 through arefrigerant passage 11 in which is disposed anexpansion device 25. As the high pressure refrigerant liquid traverses theexpansion device 25, the refrigerant liquid expands to a lower pressure and a lower temperature to form a refrigerant vapor or a saturated mixture of refrigerant liquid and refrigerant vapor at the lower pressure and the lower temperature. The lower pressure, lower temperature vapor or liquid/vapor mixture is delivered via thepassage 11 to and introduced into the shell of theevaporator 30. - The
evaporator 30 also may any one of various conventional designs. For example, for purposes of illustration, but not limitation, theevaporator 30 may be a tube-in-shell evaporator, wherein a heat transfer fluid, most commonly, and in the application described herein, water or a chemical salt solution (brine), is passed through a multiple-tube heat exchanger (not shown) housed in a closed shell into which is introduced the lower pressure, lower temperature refrigerant liquid in traversing theexpansion device 25. The lower temperature refrigerant liquid collects in the shell immersing the tubes of the heat exchanger. Thus, the water or brine passing through the tubes passes in heat exchange relationship with the liquid refrigerant in which the tubes are immersed, whereby the refrigerant liquid is heated and evaporated to a refrigerant vapor and the water or brine is cooled. - As noted previously, the
first compressor 40 and thesecond compressor 50 are each arranged in the refrigerant flow circuit between the evaporator 30 and thecondenser 20. Arefrigerant line 47 has an outlet opening into the shell of thecondenser 20 and an inlet in communication with the discharge outlet of thefirst compressor 40 whereby thefirst compressor 40 discharges higher pressure, hot refrigerant vapor into thecondenser 20. Similarly, arefrigerant line 57 has an outlet opening into the shell of thecondenser 20 and an inlet in communication with the discharge outlet of thesecond compressor 50 whereby thesecond compressor 50 discharges higher pressure, hot refrigerant vapor into thecondenser 30. - A
refrigerant line 43 has an inlet opening into the shell of theevaporator 30 and an outlet in communication with the suction inlet of thefirst compressor 40 whereby thefirst compressor 40 receives lower pressure refrigerant vapor from theevaporator 30. Similarly, arefrigerant line 53 has an inlet opening into the shell of theevaporator 30 and an outlet in communication with the suction inlet of thesecond compressor 50 whereby thefirst compressor 50 receives lower pressure refrigerant vapor from theevaporator 30. A first flow shut-offvalve 45 is interdisposed inrefrigerant line 43 upstream with respect to refrigerant flow of the suction inlet to thefirst compressor 40. A second flow shut-offvalve 55 is interdisposed inrefrigerant line 53 upstream with respect to refrigerant flow of the suction inlet to thesecond compressor 50. - The
compression machine 10 may also include a control system 80 for selectively operating thefirst compressor 40 and thesecond compressor 50. The control system may include a first controller 80-1 that is operatively associated with thefirst compressor 40 and itsdrive motor 42 and a second controller 80-2 that is operatively associated with thesecond compressor 50 and itsdrive motor 52, and amotor starter 82 that is capable of selectively starting either thefirst compressor 40 or thesecond compressor 50 as directed. The control system may also include a master controller (not shown) that selectively independently commands the first and second controllers 80-1, 80-2. In other embodiments, the control system 80 associated with thecompression machine 10 may include a single controller for controlling the first andsecond compressors compression machine 10 in a water-cooling mode during the summer cooling season to supply chilled water to an air conditioning system (not shown) of a building associated with thecompression machine 10. The control system 80 operates thecompression machine 10 in a water-heating mode during the winter heating season to provide hot water to the air conditioning system of a building associated with thecompression machine 10. For example, for purposes of illustration, but not limitation, thecompression machine 10 may need to supply chilled water at a temperature in the vicinity of about 7° C. (about 45° F.) during the summer cooling system, and need to supply hot water at a temperature in the vicinity of about 50° C. (about 122° F.) during the winter heating season. Thus, the lift requirement associated with water-cooling duty would be less than the lift requirement associated with water-heating duty. - In another application, the control system 80 may be configured during the summer to operate the
compression machine 10 in a brine-cooling mode to supply chilled brine to an air conditioning system (not shown) of a building associated with thecompression machine 10 during the hours of the day when the building is occupied and to supply chilled brine to an ice-storage system (not shown) to make ice during the hours of the night when the building occupancy is lower, such as typically at night. Chilling brine for the air-conditioning duty would have a lower lift requirement than chilling brine for ice-making duty. - The
compression machine 10 is designed for selective operation in one of a first duty mode and a second duty mode. Thefirst compressor 40 is selected for optimal operation of thecompression machine 10 in the first duty mode, for example a water-cooling mode, and thesecond compressor 50 is selected for optimal operation of thecompression machine 10 in the second duty mode, for example a water-heating mode or a brine cooling mode. In an embodiment,first compressor 40 is selected for optimal operation of the compression machine for providing chilled water passing from the refrigerant evaporator at a temperature in the range of from about 2° C. to about 12° C. (about 35° F. to about 54° F.). In an embodiment,second compressor 50 is selected for optimal operation of the compression machine for providing heated water passing from the refrigerant condenser at a temperature in the range of from about 40° C. to about 60° C. (about 104° F. to about 140° F.). In an embodiment, thesecond compressor 50 is selected for optimal operation of thecompression machine 10 for providing chilled brine to an ice thermal storage system (not shown) for use in making ice. - To operate the
compression machine 10 in the first duty mode, for example the water-cooling mode, the controller 80 closes the flow shut-offvalve 55 inrefrigerant line 53 thereby isolating thesecond compressor 50 from the refrigerant circuit, supplies electric power to thestarter 82, and commands thestarter 82 to activate thefirst drive motor 42 for driving only thefirst compressor 40. Alternately, to operate thecompression machine 10 in the second duty mode, for example the water-heating mode or brine cooling mode, the controller 80 closes the flow shut-offvalve 45 inrefrigerant line 43 thereby isolating thefirst compressor 40 from the refrigerant circuit, supplies electric power to thestarter 82, and commands thestarter 82 to activate thesecond drive motor 52 for driving only thesecond compressor 50. Therefore, when operating thecompression machine 10 in the first duty mode, thefirst compressor 40 is operated and thesecond compressor 50 is shutdown and isolated from the refrigerant circuit. Conversely, when operating hecompression machine 10 in the second duty mode, thesecond compression 50 is operated and thefirst compressor 40 is shut down and isolated from the refrigerant circuit. - The
compression machine 10 is designed for optimal energy efficiency in both the water-cooling mode and the water-heating or brine cooling mode by selecting as the first compressor 40 a first compressor selected to perform optimally in a water cooling mode only, and by selecting as the second compressor 50 a second compressor selected to perform optimally in one of a water heating mode or brine cooling mode. By selecting thesecond compressor 50 for optimal capacity and efficiency in the water heating mode or ice storage mode, wherein the lift required could be as much as about twice the lift required in the water cooling mode, thefirst compressor 40 may be selected for optimal efficiency and performance to meet the lower lift demands, while thesecond compressor 50 may be selected for optimal efficiency and performance to meet the higher lift demands. For example, in the winter, water for delivery to theevaporator 30 may be drawn from a outside water source at a temperature of about 7° C. (about 45° F.) and the hot water leaving thecondenser 20 to meet space heating demand may need to be at a temperature of about 50° C. (about 122° F.), while in the summer, water for delivery to thecondenser 20 may be from the outdoor water source at a temperature of about 32° C. (about 90° F.) and the chilled water leaving theevaporator 30 to meet air conditioning demand may need to be at a temperature of about 7° C. (about 45° F.). With a typical single compressor compression machine, the designer would necessarily need to size the compressor to meet the maximum lift requirement and compression capacity demand associated with the second duty mode and simply expect lower than optimal efficiency performance during operation in the first duty mode. However, thecompression machine 10 of the invention provides for optimal performance in both the lower lift requirement first duty mode and the higher lift requirement second duty mode. - Additionally, in an embodiment the
first compressor 40 and thesecond compressor 50 are designed to not operate at the same time. In this embodiment, thefirst compressor 40 is selected for operation in, and is only operated, when thecompression machine 10 operates in the water-cooling mode, and thesecond compressor 50 is selected for operation in, and is only operated, when thecompression machine 10 operates in the water-heating mode. In this embodiment, only onemotor starter 82. - Referring now to
FIG. 1 , it should be noted that thesecond compressor 50, which is the compressor selected for operation in the second duty mode, that is the duty mode having the higher lift requirement, is positioned opposite the end at which the water enters the evaporator. In practice, thesecond compressor 50 should be positioned as far as practical from the water inlet end to the condenser to avoid liquid carry-over inside the evaporator, which is driven by the pressure difference between the condenser and the evaporator. - The terminology used herein is for the purpose of description, not limitation. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as basis for teaching one skilled in the art to employ the present invention. While the present invention has been particularly shown and described with reference to the exemplary embodiments as illustrated in the drawing, it will be recognized by those skilled in the art that various modifications may be made without departing from the spirit and scope of the invention. Those skilled in the art will also recognize the equivalents that may be substituted for elements described with reference to the exemplary embodiments disclosed herein without departing from the scope of the present invention.
- Therefore, it is intended that the present disclosure not be limited to the particular embodiment(s) disclosed as, but that the disclosure will include all embodiments falling within the scope of the appended claims.
Claims (18)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/255,198 US20110314847A1 (en) | 2009-04-09 | 2010-04-01 | Dual duty compression machine |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16797809P | 2009-04-09 | 2009-04-09 | |
US13/255,198 US20110314847A1 (en) | 2009-04-09 | 2010-04-01 | Dual duty compression machine |
PCT/US2010/029595 WO2010117868A2 (en) | 2009-04-09 | 2010-04-01 | Dual duty compression machine |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110314847A1 true US20110314847A1 (en) | 2011-12-29 |
Family
ID=42936831
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/255,198 Abandoned US20110314847A1 (en) | 2009-04-09 | 2010-04-01 | Dual duty compression machine |
Country Status (3)
Country | Link |
---|---|
US (1) | US20110314847A1 (en) |
CN (1) | CN102388223B (en) |
WO (1) | WO2010117868A2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160084110A1 (en) * | 2013-05-21 | 2016-03-24 | Nuovo Pignone Srl | Compressor with a thermal shield and methods of operation |
USD828250S1 (en) * | 2015-08-31 | 2018-09-11 | Cummins Inc. | Compression relief brake system |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105841402A (en) * | 2016-05-19 | 2016-08-10 | 欧悦冰雪投资管理(北京)有限公司 | Oil return structure and ice-making unit comprising same |
CN107014141B (en) * | 2017-03-28 | 2020-04-21 | 南京国通制冷技术有限公司 | Air treatment system for performance test device of freezing and refrigerating cabinet |
DE102018108827B3 (en) * | 2018-04-13 | 2019-05-29 | Trumpf Schweiz Ag | Method for controlling at least one radial fan in a refrigeration system and radial fan |
CN111059657A (en) * | 2019-12-11 | 2020-04-24 | 珠海格力电器股份有限公司 | Refrigeration and ice-making air conditioning unit and control method |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4262488A (en) * | 1979-10-09 | 1981-04-21 | Carrier Corporation | System and method for controlling the discharge temperature of a high pressure stage of a multi-stage centrifugal compression refrigeration unit |
US5996356A (en) * | 1996-10-24 | 1999-12-07 | Mitsubishi Heavy Industries, Ltd. | Parallel type refrigerator |
US6829903B2 (en) * | 2002-12-20 | 2004-12-14 | Lg Electronics Inc. | Air conditioner and method for operating air conditioner in cooling mode |
US20070017240A1 (en) * | 2005-07-19 | 2007-01-25 | Hussmann Corporation | Refrigeration system with mechanical subcooling |
US7207183B2 (en) * | 2004-04-12 | 2007-04-24 | York International Corp. | System and method for capacity control in a multiple compressor chiller system |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4646530A (en) * | 1986-07-02 | 1987-03-03 | Carrier Corporation | Automatic anti-surge control for dual centrifugal compressor system |
EP1422483B1 (en) * | 2002-11-21 | 2015-10-14 | LG Electronics Inc. | Air conditioner |
JP4195031B2 (en) * | 2004-11-04 | 2008-12-10 | ウィニアマンド インコーポレイテッド | Air conditioner capacity controller |
US7478539B2 (en) * | 2005-06-24 | 2009-01-20 | Hussmann Corporation | Two-stage linear compressor |
KR100700545B1 (en) * | 2005-08-10 | 2007-03-28 | 엘지전자 주식회사 | Apparatus for controlling the driving of an air conditioner having plural compressors and method therefor |
-
2010
- 2010-04-01 US US13/255,198 patent/US20110314847A1/en not_active Abandoned
- 2010-04-01 CN CN201080015309.8A patent/CN102388223B/en not_active Expired - Fee Related
- 2010-04-01 WO PCT/US2010/029595 patent/WO2010117868A2/en active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4262488A (en) * | 1979-10-09 | 1981-04-21 | Carrier Corporation | System and method for controlling the discharge temperature of a high pressure stage of a multi-stage centrifugal compression refrigeration unit |
US5996356A (en) * | 1996-10-24 | 1999-12-07 | Mitsubishi Heavy Industries, Ltd. | Parallel type refrigerator |
US6829903B2 (en) * | 2002-12-20 | 2004-12-14 | Lg Electronics Inc. | Air conditioner and method for operating air conditioner in cooling mode |
US7207183B2 (en) * | 2004-04-12 | 2007-04-24 | York International Corp. | System and method for capacity control in a multiple compressor chiller system |
US20070017240A1 (en) * | 2005-07-19 | 2007-01-25 | Hussmann Corporation | Refrigeration system with mechanical subcooling |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20160084110A1 (en) * | 2013-05-21 | 2016-03-24 | Nuovo Pignone Srl | Compressor with a thermal shield and methods of operation |
JP2016520754A (en) * | 2013-05-21 | 2016-07-14 | ヌオーヴォ ピニォーネ ソチエタ レスポンサビリタ リミタータNuovo Pignone S.R.L. | Compressor with thermal shield and method of operation |
US10711641B2 (en) * | 2013-05-21 | 2020-07-14 | Nuovo Pignone Srl | Compressor with a thermal shield and methods of operation |
USD828250S1 (en) * | 2015-08-31 | 2018-09-11 | Cummins Inc. | Compression relief brake system |
Also Published As
Publication number | Publication date |
---|---|
CN102388223A (en) | 2012-03-21 |
WO2010117868A2 (en) | 2010-10-14 |
WO2010117868A3 (en) | 2011-01-13 |
CN102388223B (en) | 2017-06-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9587867B2 (en) | Chiller system and control method thereof | |
US20110314847A1 (en) | Dual duty compression machine | |
CN103185376A (en) | Heat pump and control method thereof | |
EP3324134B1 (en) | Absorption subcooler for a refrigeration system | |
CN103776114A (en) | Direct expansion type heat pump type comprehensive energy utilization system and control method thereof | |
KR101914163B1 (en) | Multi heat source integrating type heat pump system | |
CN102788447A (en) | Heat pump air conditioning system and water dispenser | |
CN104266417A (en) | Refrigeration operating method of multi-split air conditioner in high temperature environment | |
JP2009236441A (en) | Heat pump type refrigerating device | |
KR200281266Y1 (en) | Heat pump system | |
CN111251812B (en) | Thermal management system of vehicle and vehicle | |
JPS58200945A (en) | Heat source device for water heat-source heat pump type air-conditioning unit | |
KR101753086B1 (en) | Hybrid type air conditioning and heat pump system | |
JP2011122801A (en) | Air heat source heat pump system and method of operating the same | |
JP2011106718A (en) | Heat pump chiller | |
KR101658223B1 (en) | Cooling-Storage System | |
KR100877055B1 (en) | Hybrid heat pump type heat and cooling system with feeding steam water | |
CN207487211U (en) | Refrigeration system and the refrigerating transport vehicle for having the refrigeration system | |
JP2006017440A (en) | Heat pump air conditioner | |
KR101031337B1 (en) | Compound type perfect air handing unit | |
CN219037171U (en) | Flexible heat pump system using three-medium heat exchange module | |
CN216384419U (en) | Four-pipe air-cooled cold and hot water unit | |
CN220911563U (en) | Air conditioner | |
CN110035644B (en) | Centralized cooling type heat pipe air conditioner multi-split system | |
KR100443428B1 (en) | air condition system to use of gas engine heat pump |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: CARRIER CORPORATION, CONNECTICUT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DING, HAIPING;REEL/FRAME:026867/0360 Effective date: 20090409 |
|
AS | Assignment |
Owner name: CARRIER CORPORATION, CONNECTICUT Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE ADD ASSIGNOR NAME PREVIOUSLY RECORDED ON REEL 026867 FRAME 0360. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT;ASSIGNORS:STARK, MICHAEL A.;DING, HAIPING;REEL/FRAME:027160/0871 Effective date: 20090409 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |