CN101796299A

CN101796299A - Capacity modulated compressor

Info

Publication number: CN101796299A
Application number: CN200880104966A
Authority: CN
Inventors: 克里斯托弗·斯托弗; 史蒂芬·M·塞贝尔
Original assignee: Emerson Climate Technologies Inc
Current assignee: Copeland LP
Priority date: 2007-07-02
Filing date: 2008-06-09
Publication date: 2010-08-04
Also published as: EP2012017A2; KR20100025539A; US20090071183A1; EP2012017A3; WO2009005574A1

Abstract

A heat pump system may include first and second heat exchangers, a compressor, and a fluid conduit. The compressor may include a capacity modulation system providing first, second, and third capacities of the compressor. The second capacity may be less than the first capacity and greater than the third capacity. The fluid conduit may provide fluid communication between the first and second heat exchangers and the compressor. The fluid conduit may define a first flow path from the compressor to the first heat exchanger and from the first heat exchanger to the second heat exchanger during a cooling mode and a second flow path from the compressor to the second heat exchanger and from the second heat exchanger to the first heat exchanger during a heating mode. The compressor may operate at the first capacity during the heating mode and at the second capacity during the cooling mode.

Description

Capacity modulated compressor

Technical field

The present invention relates to heat pump, and relate more specifically to the compressor in the heat pump, this compressor comprises capacity modulation.

Background technique

Statement in this section only provides background information related to the present invention, may not constitute prior art.

When moving under refrigerating mode, the heat pump with two-stage capacity modulation can provide system's operation of improvement.More specifically, first compressor capacity can with refrigerating mode down the system's working capacity during operation be associated, and second capacity can be used to reduce compressor capacity, is used to improve the underloading performance during the refrigerating mode.Desired compression machine capacity under the refrigerating mode, the heat pump operation under heating mode may need bigger compressor capacity.Thus, the thermal source that may need to add provides heating mode required heat.Alternately, the big I of system's rated capacity of compressor is configured to greater than capacity required under the refrigerating mode, thereby makes compressor that enough heating properties can be provided under heating mode.Yet excessive system's rated capacity may cause the compressor operating of poor efficiency under the refrigerating mode.

Summary of the invention

Therefore, compressor can comprise shell and be contained in compressing mechanism in the shell.This compressing mechanism can comprise first and second scroll elements, and described scroll element is supported, is used for the relative moving motion between them.First and second scroll elements all can comprise the end plate with spiral wraps, and described spiral wraps is engaged with each other from the end plate extension and in the mode that meshes, thereby forms a plurality of chambeies.First path can be arranged in described first scroll element, and from the outside of described first scroll element extends to the described chamber first.Alternate path can be arranged in first scroll element and extend among in the described chamber second, and this second chamber radially inwardly is provided with respect to described first chamber.Compressor also can comprise valve assembly, in order to optionally to open and close described first and second paths, the 3rd working capacity that second working capacity that alternate path is closed thereby first working capacity, described first path that provide described first and second paths all to close are opened and described alternate path are opened.Compressor can be arranged in the heat pump, and wherein said first working capacity is corresponding to the heating mode of heat pump, and described the 3rd working capacity is corresponding to the refrigerating mode of heat pump.

A kind of heat pump can comprise first and second heat exchangers, compressor and fluid line.Compressor can comprise the capacity modulation of first, second and the 3rd working capacity that described compressor is provided.Second working capacity can be less than first working capacity and greater than described the 3rd working capacity.Fluid line can provide first heat exchanger and second heat exchanger to be communicated with fluid between the compressor.Fluid line limits from compressor to first heat exchanger and first flow path from first heat exchanger to second heat exchanger in the time of can moving under refrigerating mode, and limits from compressor to second heat exchanger and second flow path from second heat exchanger to first heat exchanger can move under heating mode the time.Compressor can move under first working capacity during the heating mode, and is moving under second working capacity during the refrigerating mode.

The method of the scroll compressor in a kind of operating heat pump system, comprise first leakage paths that sealing is communicated with first chamber and seal second leakage paths that is communicated with second chamber, thereby scroll compressor is being moved during the heating mode of heat pump under first working capacity, described first chamber is that the scrollwork engagement ground by first scroll element that makes the described scroll compressor that moves under first pressure and second scroll element engages first in the chamber that forms, described second chamber is that the scrollwork engagement ground by first scroll element that makes the described scroll compressor that moves under second pressure and second scroll element engages second that forms in the chamber, and described second pressure is greater than described first pressure.Described method also can comprise to be opened described first leakage paths and closes described second leakage paths, thereby described compressor is being moved under second working capacity during the refrigerating mode of described heat pump, and this second working capacity is less than described first working capacity.Described method also can comprise opens described second leakage paths, thereby described compressor is being moved under the 3rd working capacity during the described refrigerating mode, and the 3rd working capacity is less than described second working capacity.

By the description that provides at this, further Applicable scope will become apparent.Should be understood that described description and specific example only are used for the purpose of example, and be not intended to restriction the scope of the present disclosure.

Description of drawings

Accompanying drawing described here only is used to illustrate purpose, is not to be intended to limit by any way the scope of the present disclosure.

Fig. 1 is the indicative icon according to heat pump of the present disclosure.

Fig. 2 is the sectional view of the compressor of the heat pump among Fig. 1.

Fig. 3 is the non-moving vortex of the compressor among Fig. 2 and the sectional view of capacity modulation.

Fig. 4 is the non-moving vortex of the compressor among Fig. 2 and another sectional view of capacity modulation.

Fig. 5 is the non-moving vortex of the compressor among Fig. 2 and another sectional view of capacity modulation, and

Fig. 6 is the non-moving vortex of the compressor among Fig. 2 and the perspective view of capacity modulation.

Embodiment

Ensuing description in fact only is exemplary, and is not intended to the restriction disclosure, application or use.Should be understood that, in institute's drawings attached, like the corresponding reference character representation class or corresponding parts and feature.

As shown in Figure 1, heat pump 10 can comprise indoor unit 12 and outdoor unit 14.Indoor unit 12 can comprise indoor coil or heat exchanger 16, and the variable speed indoor fan 18 that is driven by motor 20.Indoor coil 16 and fan 18 can be enclosed in the cabinet 22, thereby force atmosphere to pass indoor coil 16 by fan 18.Outdoor unit 14 can comprise outdoor coil or heat exchanger 24 and the variable speed outdoor fan 26 that is driven by motor 28.Outdoor coil 24 and fan 26 can be enclosed in the protection housing 30, thereby fan 26 suction outside atmosphere are passed outdoor coil 24 to improve heat transmission.Outdoor unit 14 can further comprise compressor 32, and this compressor 32 is connected with indoor coil 16 and outdoor coil 24.

Connection between compressor 32, indoor coil 16 and the outdoor coil 24 can form ring usually, wherein compressor 32, indoor coil 16 and outdoor coil 24 setting that is one another in series, and wherein expansion gear 33 is arranged between indoor coil 16 and the outdoor coil 24.Heat pump 10 can comprise the reversing valve 34 that is arranged between compressor 32 and indoor coil 16, the outdoor coil 24, so that the flow direction between compressor 32, indoor coil 16 and the outdoor coil 24 can conversion between first direction and second direction.On first direction, heat pump 10 moves under refrigerating mode, thereby flowing on the direction shown in " cooling " arrow is provided.Under refrigerating mode, compressor 32 provides fluid to outdoor coil 24.This fluid advances to indoor coil 16 subsequently and turns back to compressor 32 subsequently.Under refrigerating mode, indoor coil 16 is as evaporator coil, and outdoor coil 24 is as condenser coil.On second direction, heat pump 10 moves under heating mode, thereby flowing on the direction shown in " heating " arrow is provided.Under heating mode, flowing becomes oppositely, promptly from compressor 32 row: enter indoor coil 16 again to outdoor coil 24, and turn back to compressor 32 subsequently.Under heating mode, indoor coil 16 is as condenser coil, and outdoor coil 24 is as evaporator coil.

Property purpose presented for purpose of illustration, condenser 32 is illustrated as the sealing vortex refrigeration compressor of low side type, and the wherein cooling of the intake-gas in the sealed shell of motor and compressor is shown in the vertical cross-section figure of Fig. 2.Compressor 32 can comprise cylindrical seal shell 116, compressing mechanism 118, main bearing housing 120, motor sub-assembly 122, refrigeration agent outlet fitting 124 and intake-gas inlet fitting 126.Can 116 can hold compressing mechanism 118, main bearing shell 120 and motor sub-assembly 122.Shell 116 can comprise the end cap 128 of its upper end and the divider 129 of horizontal expansion.Refrigeration agent outlet fitting 124 can be connected to shell 116 at 130 places of the opening in the end cap 128.Intake-gas inlet fitting 126 can be connected to shell 116 at opening 132 places.Compressing mechanism 118 can be driven and be supported by main bearing housing 120 by motor sub-assembly 122.Main bearing housing 120 can be fixed to shell 116 at a plurality of points by any desirable mode.

Motor sub-assembly 122 can generally include motor 134, framework 136 and live axle 138.Motor 134 can comprise motor stator 140 and rotor 142.Motor stator 140 can be press fitted in the

framework

136, and 136 of this frameworks are press fitted in the shell 116.Live axle 138 is rotatably driven by rotor 142.Winding 144 can pass stator 140.Rotor 142 can be press fitted on the live axle 138.Motor protector 146 can be arranged to be close to winding 144, thereby if winding 144 surpasses their normal temperature range, then motor protector 146 will be removed excitation to motor 134.

Live axle 138 can comprise eccentric crankpin 148, has par 149 on this eccentric crankshaft pin 148 and 152 has counterweight 150 in the top.Live axle 138 can comprise that axle journal rotatably supports first necked part 153 in (journaled) clutch shaft bearing 154 in main bearing housing 120, and rotatably axle journal is supported on second necked part 155 in second bearing 156 in framework 136.Live axle 138 comprises pump oil concentric hole 158 and the counterweight 159 that is positioned at lower end 160.Concentric hole 158 can be communicated with radially outward-dipping and the relative less hole 162 of diameter, and this hole 162 extends to the upper end 152 of live axle 138.The inner lower part of shell 116 can be filled with lubricant oil.Concentric hole 158 can provide pump action together with hole 162, thereby lubricating fluid is assigned to the various piece of compressor 32.

Compressing mechanism 118 can generally include moving vortex 164 and non-moving vortex 166.Moving vortex 164 can comprise end plate 168, has helical blade or scrollwork (wrap) 170 on the upper surface of end plate 168, and its lower surface has the smooth directed thrust directed thrust surfaces 172 of annular.Directed thrust directed thrust surfaces 172 can have a common boundary with the annular planar thrust bearing surface 174 on the upper surface of main bearing housing 120 (interface).Cylindrical hub 176 can be stretched out downwards and can comprise shaft bearing 178 from directed thrust directed thrust surfaces 172, and shaft bearing 178 has the driving lining 180 that is arranged in rotary manner wherein.Drive lining 180 and can comprise internal holes, be arranged in this internal holes to crankpin 148 driven natures.The par 149 of crankpin can with plat surface driven nature in the part of the internal holes that drives lining 180 engage, thereby the driving device of radial compliance (compliant) is provided.

Non-moving scroll element 166 can comprise end plate 182, has spiral wraps 184 on the lower surface 186 of this end plate 182.Spiral wraps 184 can form engagement with the scrollwork 170 of moving scroll element 164 and engage, and is formed into oral cavity 188, intermediate cavity 190,192,194,196 and outlet plenum 198 thus.Non-moving vortex 166 can have the vent pathway 200 of setting placed in the middle and the recess 202 of upward opening, and described vent pathway 200 is communicated with outlet plenum 198, and described recess 202 can be communicated with vent silencer 201 fluids by the opening 203 in the divider 129.Vent silencer 201 can be communicated with outlet fitting 124 and can be limited by end cap 128 and divider 129.

Can comprise annular recess 204 in the upper surface of non-moving scroll element 166, this annular recess 204 has parallel coaxial sidewall, and annular floating seal 205 is arranged on wherein with sealing means, is used for relative axial motion.The bottom of recess 204 can be by floating seal 205 and the gas barrier that is under suction and the discharge pressure, thereby can be by means of path 206 and central fluid pressure-source communication (as shown in Fig. 3-5).Path 206 may extend in the intermediate cavity 190,192,194,196.Non-moving vortex 166 can axially be biased on the moving scroll element 164 by power that discharge pressure produced on the core that acts on scroll element 166 and the power that is produced by the central fluid pressure that acts on recess 204 bottoms thus.Also can be used for the limited axial motion of scroll element 166 in the compressor 32 in conjunction with multiple other technology.

Can prevent the relative rotation of scroll element 164,166 by the Oldham coupling, described Oldham coupling can comprise usually the ring 212, this ring 212 have slidably be arranged on non-moving vortex 166 along the pair of keys 214 (demonstrating) in the relative groove 216 of diameter (demonstrating) and slidably be arranged in the moving vortex 164 along second pair of key (not shown) in the relative groove of diameter.

With reference to figure 3 to Fig. 5, non-moving scroll element 166 can comprise first, second, third and four-way road 218,220,222,224, and the outer side wall 226 that described path passes non-moving scroll element 166 extends in the intermediate flow body cavity 190,192,194,196.First, second, third and four-way road 218,220,222,224 all can comprise be arranged on its outlet in Sealing 225.Compare first and second paths 218,220 and can have bigger radially inside length in third and

fourth path

222 and 224 one or whole two.With reference to figure 6, capacity modulation 228 can be connected in non-moving scroll element 166 in addition.

Capacity modulation 228 can comprise regulating ring 230 and actuating mechanism 232.Sealing 225 can engage with regulating ring 230.Regulating ring 230 comprises rotatably the main body of the cardinal principle annular that the outer side wall 226 around non-moving scroll element 166 is provided with.Regulating ring 230 can comprise first and second parts 234,236, first and second parts 234,236 have first flow path 238,239 and second flow path 240,241 that extends through described part separately, be used for the one or more of middle fluid chamber 190,192,194,196 are optionally discharged, this will be described below.Pin 242 extends from regulating ring 230, is used for engaging with actuating mechanism 232.

Actuating mechanism 232 can be solenoidal form, and it has extended and retractible arm 244.The biasing member (not shown), helical spring for example can be with arm 244 normal pressures to extended position.Can comprise recess 248 in the end 250 of arm 244.Pin 242 may extend in the recess 248, is used to activate regulating ring 230, and this will be described below.

Referring to Fig. 3 to Fig. 5, actuating mechanism 232 can make regulating ring 230 rotate between three positions.In primary importance (as shown in Figure 3), compressor 32 moves with maximum capacity.Under maximum capacity, first and second parts 234,236 of regulating ring 230 seal up the path 218,220,222,224 in the non-moving scroll element 166.More specifically, in primary importance, first flow path 238,239 is not communicated with first and second paths 218,220, and second flow path 240,241 is not communicated with third and fourth path 222,224.By the withdrawal of arm 244 and thus regulating ring 230 be rotated in a clockwise direction the second place (as shown in Figure 4) and by arm 244 stretch out and thus regulating ring 230 rotate to the 3rd position (as shown in Figure 5) in the counterclockwise direction, can pondage.

Second capacity is less than first capacity.When in second capacity following time, arm 244 can be in inner side, and first flow path 238,239 of regulating ring 230 can align with first and second paths 218,220 in the non-moving scroll element 166.Capacity also can be adjusted to the 3rd capacity (as shown in Figure 5), and wherein regulating ring 230 is rotated to the 3rd position.The 3rd capacity is less than second capacity.When in the 3rd capacity following time, arm 244 is extended to outermost locations, thereby makes regulating ring 230 rotate to the 3rd position from the second place in the counterclockwise direction.The 3rd position can make between third and fourth path 222,224 in first flow path 238,239 and the non-moving scroll element 166 and second flow path 240,241 and non-moving scroll element 166 in first and second paths 218,220 between align.

As mentioned above, less than second capacity, reason is that third and fourth path 222,224 has bigger radially inside length in the non-moving scroll element 166 to first capacity greater than second capacity and the 3rd capacity.First, second, third and four-way road 218,220,222,224 radially inwardly length can reduce non-moving scroll element 166 effectively hold length (wrap length).For example, non-moving vortex 166 has the angle that holds of about 1330 degree.First and second paths 218,220 may extend in the non-moving scroll element, and what reach about 1000 degree of beginning from the basic circle of involute holds angle.Thus, under first and second paths 218,220 and second capacity that first flow path 238,239 is communicated with, the angle that holds of non-moving vortex 166 is reduced to 1000 degree effectively.Third and fourth path 222,224 may extend in the non-moving vortex 166, and what reach about 660 degree of beginning from the basic circle of involute holds angle.Thus, first and second paths 218,220 be communicated with second flow path 240,241 and third and fourth path 222,224 and the 3rd capacity that first flow path 238,239 is communicated with under, the angle that holds of non-moving scroll element 166 is reduced to 660 degree effectively.

The capacity of swirl chamber can be with to hold angle proportional substantially.Thus, according to top example, comparable second capacity of first capacity is big substantially by 33%, and comparable second capacity of the 3rd capacity is substantially little by 33%.Yet, the basic big 10%-35% of comparable second capacity of first capacity, and the substantially little 10%-35% of comparable second capacity of the 3rd capacity.Regulating ring 230 can be maintained at constant position, thereby three capacity recited above are provided.Alternately, regulating ring 230 can circulate apace, thus capacity in the middle of providing.

The size of compressor 32 is configured such that when heat pump 10 moved, second capacity was corresponding with system's rated capacity of compressor 32 under refrigerating mode.When heat pump 10 moved under heating mode, compressor 32 can move under first and second capacity.First capacity can provide extra capacity to be used for moving under heating mode.More specifically, when compressor 32 moved under first capacity, the overhead provision that is provided can reduce in the heat pump 10 needs for the reserve heat, and can improve heating figure of merit in season (HSPF).For example, if the size of compressor 32 is provided in the cooling capacity that has 3 tons under second capacity, and the cooling capacity that under first capacity, has 4 tons, the HSPF value of heat pump 10 can reach than the heat pump with fixed-capacity compressor larger about 6% so.

When heat pump 10 moved under refrigerating mode, compressor 32 can move under the second and the 3rd capacity.More specifically, the 3rd capacity can provide the operation more efficiently of heat pump 10 under the underloading refrigerating mode.When heat pump 10 moved under refrigerating mode, what provided when compressor 32 moves under the 3rd capacity reduced capacity and can improve seasonal energy efficiency ratio (seer) (SEER).For example, if the size of compressor 32 is provided in the cooling capacity that has 3 tons under second capacity, and the cooling capacity that under the 3rd capacity, has 2 tons, heat pump 10 available SEER values reach than the same system with fixed-capacity compressor larger about 7% so.Capacity reduces to reach than the same system that has fixed-capacity compressor and do not have a variable speed indoor and outdoors fan larger about 18% with variable speed indoor and outdoors fan 18,26 combined producible SEER values.

Claims

1. compressor comprises:

Shell;

Compressing mechanism, described compressing mechanism is contained in the described shell and comprises first scroll element and second scroll element, described first scroll element and second scroll element are supported for the relative moving motion between them, described first scroll element and second scroll element include end plate, described end plate has the spiral wraps of extending from described end plate, and the described spiral wraps of described first scroll element and second scroll element is engaged with each other in the mode that meshes and forms a plurality of chambeies;

First path, described first channel setting are in described first scroll element and from the outside of described first scroll element extends to the described chamber first;

Alternate path, described alternate path are arranged in described first scroll element and extend among in the described chamber second, and this second chamber radially inwardly is provided with respect to described first chamber; And

Valve assembly, described valve assembly can be operable to and optionally open and close described first path and alternate path, the 3rd working capacity that second working capacity that described alternate path is closed thereby first working capacity, described first path that provide described first path and described alternate path both to close are opened and described alternate path are opened, described compressor is arranged in the heat pump, wherein said first working capacity is corresponding to the heating mode of described heat pump, and described the 3rd working capacity is corresponding to the refrigerating mode of described heat pump.

2. compressor as claimed in claim 1, wherein when moving under described second working capacity, described compressing mechanism moves under refrigerating mode system rated capacity.

3. compressor as claimed in claim 2, wherein said second working capacity is less than described first working capacity and greater than described the 3rd working capacity.

4. compressor as claimed in claim 3, wherein said first working capacity is than the big 10%-35% of described second working capacity.

5. compressor as claimed in claim 3, wherein said the 3rd working capacity is than the little 10%-35% of described second working capacity.

6. compressor as claimed in claim 1, also comprise the 3rd path and the four-way road that are arranged in described first scroll element, described the 3rd path is from the outside of described first scroll element extends to the described chamber the 3rd, and described four-way road is from the outside of described first scroll element extends to the described chamber the 4th, and described the 4th chamber radially inwardly is provided with respect to described first chamber and the 3rd chamber.

7. compressor as claimed in claim 6, wherein said first working capacity comprise closes described first path, alternate path, the 3rd path and four-way road.

8. compressor as claimed in claim 6, wherein said second working capacity comprise closes described alternate path and four-way road and opens described first path and the 3rd path.

9. compressor as claimed in claim 6, wherein said the 3rd working capacity comprise opens described alternate path and four-way road.

10. compressor as claimed in claim 9, wherein said the 3rd working capacity comprise opens described first path and the 3rd path.

11. compressor as claimed in claim 1, wherein said first scroll element are non-moving scroll elements.

12. comprising, compressor as claimed in claim 1, wherein said the 3rd working capacity open described first path.

13. compressor as claimed in claim 1, wherein said valve assembly comprises regulating ring, this regulating ring is around the outer side wall setting of described first scroll element and can move between corresponding to primary importance, the second place and the 3rd position of described first working capacity, second working capacity and the 3rd working capacity, thereby optionally opens described first path and alternate path.

14. compressor as claimed in claim 13, wherein said valve assembly comprises solenoid, and described solenoid is used to make described regulating ring to move between described primary importance, the second place and the 3rd position.

15. a heat pump comprises:

First heat exchanger;

Second heat exchanger;

Compressor, described compressor comprise the capacity modulation of first working capacity, second working capacity and the 3rd working capacity that described compressor is provided, and described second working capacity is less than described first working capacity and greater than described the 3rd working capacity; And

Fluid line, described fluid line provides described first heat exchanger, fluid between described second heat exchanger and the described compressor is communicated with, described fluid line limits from described compressor to described first heat exchanger and first flow path from described first heat exchanger to described second heat exchanger when moving under refrigerating mode, and limit from described compressor to described second heat exchanger and second flow path when under heating mode, moving from described second heat exchanger to described first heat exchanger, described compressor is moving under described first working capacity during the described heating mode, and is moving under described second working capacity during the described refrigerating mode.

16. heat pump as claimed in claim 15, wherein said compressor comprise the system's rated capacity that is used for described refrigerating mode, this system's rated capacity is corresponding to described second working capacity.

17. heat pump as claimed in claim 15, wherein said first working capacity is than the big 10%-35% of described second working capacity.

18. heat pump as claimed in claim 15, wherein said the 3rd working capacity is than the little 10%-35% of described second working capacity.

19. heat pump as claimed in claim 15, wherein said compressor is a scroll compressor.

20. a method comprises:

Second leakage paths that first leakage paths that sealing is communicated with first chamber and sealing are communicated with second chamber, thereby scroll compressor is being moved during the heating mode of heat pump under first working capacity, described first chamber is that the scrollwork engagement ground by first scroll element that makes the described scroll compressor that moves under first pressure and second scroll element engages first in the chamber that forms, described second chamber is that the scrollwork engagement ground by first scroll element that makes the described scroll compressor that moves under second pressure and second scroll element engages second in the chamber that forms, and described second pressure is greater than described first pressure;

Open described first leakage paths and close described second leakage paths, thereby described compressor is being moved under second working capacity during the refrigerating mode of described heat pump, this second working capacity is less than described first working capacity; And

Open described second leakage paths, thereby described compressor is being moved under the 3rd working capacity during the described refrigerating mode, the 3rd working capacity is less than described second working capacity.

21. method as claimed in claim 20 wherein saidly makes compressor comprise in operation under described first working capacity described compressor is being moved under big 10% the capacity than described second working capacity at least.

22. method as claimed in claim 20, wherein said compressor is moved comprise under described the 3rd working capacity described compressor is moved at least under the capacity than described second working capacity little 10%.

23. method as claimed in claim 20 wherein during described refrigerating mode, is moved under described the 3rd working capacity by making described compressor, seasonal energy efficiency ratio (seer) (SEER) grade increases than the operation under described second working capacity.

24. method as claimed in claim 20 wherein during described heating mode, is moved under described first working capacity by making described compressor, heating figure of merit in season (HSPF) grade increases than the operation under described second working capacity.

25. method as claimed in claim 20, system's rated capacity that wherein said second working capacity is described refrigerating mode.

26. method as claimed in claim 20 also comprises and open described first leakage paths so that described compressor moves under described the 3rd working capacity.