Controlled direct drive engine system

• US 6,470,683 B1
• Filed: 08/29/2000
• Issued: 10/29/2002
• Est. Priority Date: 08/30/1999
• Status: Active Grant

• Current Assignee: Leidos, Inc. (Leidos Holdings, Inc.)
• Original Assignee: Science Applications International Corporation
• Inventors: Childs, Willard D., Dabiri, Ali
• Primary Examiner(s): NGUYEN, HOANG M
• Application Number:
  US09/650,390
• Time in Patent Office: 791 Days
• Field of Search: 60/396, 606/418, 604/28
• US Class Current: 60/641.8
• CPC Class Codes: B01D 2313/246 Energy recovery means
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: B01D 61/06 Energy recovery
• CPC Class Codes: B01D 61/10 Accessories; Auxiliary operations
• CPC Class Codes: B01D 61/12 Controlling or regulating
• CPC Class Codes: F02B 71/04 Adaptations of such engines for special use; Combinations of such engines with apparatus driven thereby
• CPC Class Codes: F05B 2200/12 Subtraction

Abstract

A controlled direct drive engine efficiency uses positive-displacement power produced from a thermal energy source (or sources), which may include combustion energy. Engine power production is from a plurality of cylinders appropriately controlled by a hydraulic drive unit to add to or subtract from such power output to adjust cyclic variations, thus producing a desired velocity profile for a piston (or other mover) in a fluid-displacement cylinder that is being used to effect pumping (or compressing) of liquids, gases, or vapors. The overall system is particularly suited to use a Modified Brayton thermodynamic cycle where the power output is delivered through a common rod to a positive displacement fluid pumping or compressing device. Interconnected with that common rod is a double-acting hydraulic cylinder which is operated in conjunction with a rotary, variable volume hydraulic motor/pump to effect the desired adjustment. By using a plurality of power outputs from such a Modified Brayton cycle (or other cycle), which outputs are phased to operate complementary to one another, power is transferred between individual power outputs to efficiently and smoothly operate a plurality of fluid-displacement devices.

Claims

1. A power producing system particularly suited for positive displacement fluid pumping, which system comprises:

first means for producing reciprocating power from a thermal energy source which may include combustion energy,

positive displacement fluid-displacement means including piston means for pumping/compressing fluid in a cylinder, which piston means is driven by said first means, and

a hydraulic drive unit mechanically connected to said piston means for controlling said reciprocating power from said first means to achieve efficient operation by moving said piston means with a desired velocity profile.

2. The system of claim 1 wherein said first means includes:

means for compressing a working fluid;

means for heating said compressed fluid; and

first cylinder means for expanding said heated compressed fluid to produce said reciprocating power.

3. The system of claim 2 wherein said compressing means includes second cylinder means mechanically interconnected with and driven by said first cylinder means.

4. The system of claim 3 wherein there are a plurality of subcombinations of said first and second cylinder means, with said subcombinations producing complementary reciprocating power outputs,

wherein said fluid-displacement means includes a plurality of said piston means, and

wherein said hydraulic drive unit transfers power between said plurality of reciprocating power outputs and between said plurality of piston means so as to achieve efficient operation of said fluid-displacement means.

5. The system of claim 4 wherein said hydraulic drive unit includes a plurality of rotary hydraulic power means which can function as a pump or a motor.

6. The system of claim 5 wherein said plurality of rotary hydraulic power means are mechanically interconnected so as to all rotate at the same speed and so as to transfer power back and forth therebetween.

7. The system of claim 2 wherein said first means includes a modified Brayton cycle engine which delivers reciprocating power, wherein said piston means operates in a double-acting cylinder and is linked by a common rod to said first cylinder means, wherein said hydraulic drive unit includes a double-acting cylinder which is also mechanically linked as part of said common rod, and wherein a control unit is included which controls said engine, said fluid-displacement means and said hydraulic drive unit to efficiently drive said double-acting cylinders of said fluid-displacement unit so as to move fluid on both forward and rearward strokes by adding power to or subtracting power from the stroke of said common rod to achieve said desired velocity profile of said piston means.

8. The system of claim 2 wherein said first cylinder means is a double-acting cylinder;

wherein said compressing means includes a second double-acting cylinder linked to said first cylinder means;

wherein said fluid-displacement means includes a double-acting cylinder wherein said piston means resides; and

wherein said hydraulic drive unit includes a double-acting cylinder mechanically linked to said piston means and to said first cylinder means by a common rod and a rotary variable volume hydraulic motor/pump for controlling said output power from said first cylinder means to obtain said desired velocity profile and achieve efficient pumping operation.

9. The system of claim 8 wherein there are a plurality of said first cylinder means producing reciprocating power output and a plurality of fluid-displacement cylinders;

wherein there is control means for operating said plurality of first cylinder means in complementary relationship,

wherein said hydraulic drive unit includes a plurality of combinations of one said double-acting cylinder and one said rotary motor/pump, and means interconnecting said rotary motor/pumps so that all rotate at the same speed and so that power can be transferred therebetween, and

wherein said control means transfers power between said plurality of reciprocating power outputs so as to achieve efficient pumping operation of said plurality of fluid-displacement cylinders.

10. The system of claim 9 wherein said hydraulic drive unit includes a rotary shaft which interconnects said plurality of motor/pumps and wherein an electric motor/generator is connected to said rotary shaft.

11. A combination of a modified Brayton cycle engine for delivering reciprocating power output, a fluid-displacement unit, a hydraulic drive unit which includes a double-acting cylinder, and a control unit, wherein a common rod unites said power output, said hydraulic drive unit cylinder and said fluid-displacement unit, said control unit being designed to operate said hydraulic drive unit to add power to or subtract power from said common rod to achieve a desired velocity profile for said fluid displacement unit that assures efficient and smooth operation.

12. The combination of claim 11 wherein said engine includes double-acting expander cylinders and said fluid-displacement unit includes cylinders which move fluid on both forward and rearward strokes.

13. The combination of claim 12 wherein said engine produces a plurality of reciprocating power outputs which are controlled through said control unit to complement one another, wherein said fluid-displacement unit includes a plurality of double-acting cylinders that move said fluid on both forward and rearward strokes that are respectively connected via said common rods to one of said power outputs and wherein said hydraulic drive unit transfers power among said common rods to efficiently utilize said plurality of power outputs.

14. A power producing system which comprises:

a plurality of first means for producing reciprocating power through a rod from a thermal energy source which may include combustion energy,

a plurality of linear hydraulic units, one of which is mechanically connected to each said rod,

a plurality of rotary hydraulic power units which can function as a rotary pump or a motor, one of which units is associated with each said linear hydraulic unit,

means interconnecting said rotary motor/pumps so that all rotate at the same speed and so that power can be transferred therebetween, and

a control unit which operates said plurality of first power-producing means complementary to one another and controls the operation said hydraulic rotary power units so as to add power to or subtract power from said individual linear units and in this manner controls said plurality of first reciprocating power-producing means.

15. The system according to claim 14 wherein said interconnecting means is a common rotary shaft to which electrical generating means is also connected.

16. A method for positive-displacement fluid pumping employing a reciprocating thermal engine, which method comprises the steps of:

providing a high temperature, high pressure fluid and expanding said fluid to produce reciprocating power output;

transferring said power from said expanding step to carry out positive-displacement pumping/compressing and

adjusting said output power through the use of a hydraulic drive unit to independently add to or subtract from said power output to achieve a desired velocity profile for said pumping/compressing to effect efficient operation.

17. The method of claim 16 wherein said adjusting step includes linking a piston of a hydraulic cylinder with said reciprocating power output and employing a rotary variable volume hydraulic motor/pump for said transferring by assisting or deterring movement of the piston and thereby controlling said pumping/compressing operation.

18. The method of claim 16 wherein a plurality of separate expansions of high-temperature fluid are carried out to produce a plurality of reciprocating power outputs,

wherein said plurality of expansions are controlled to produce said power outputs in complementary relationship,

wherein each of said plurality of power outputs is transferred to individually carry out said pumping/compressing, and

wherein said adjusting step uses said hydraulic drive unit to also transfer power between said plurality of reciprocating power outputs and thereby achieve efficient pumping/compressing.

19. A power producing system particularly suited for providing rotary power output, which system comprises:

first means for producing reciprocating power from a thermal energy source, which may include combustion energy, which includes piston means,

a hydraulic drive unit mechanically connected to said piston means for controlling said power from said first means to achieve efficient operation by moving said piston means with a desired velocity profile;

wherein said hydraulic drive unit includes a double-acting cylinder mechanically linked to said first cylinder means by a common rod and to a rotary variable volume hydraulic pump/motor;

a rotary output shaft from said hydraulic drive unit to achieve efficient rotary power output.

20. The system of claim 19 wherein said first reciprocating power-producing means includes:

means for compressing a working fluid;

means for heating said compressed fluid;

first cylinder means for expanding said heated compressed fluid to produce said reciprocating power, and second cylinder means mechanically interconnected with and driven by said first cylinder means.