Parallel-compound dual-fluid heat engine

• US 3,978,661 A
• Filed: 12/19/1974
• Issued: 09/07/1976
• Est. Priority Date: 12/19/1974
• Status: Expired due to Term

• Current Assignee: Cheng Power Systems, Inc. (NRG Energy, Inc.)
• Original Assignee: International Power Technology
• Inventors: Cheng, Dah Yu
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Casaregola, L. J.
• Application Number:
  US05/534,479
• Time in Patent Office: 628 Days
• Field of Search: 60/39.55, 60/39.05, 60/39.18 B, 60/39.52, 60/39.02, 60/39.53, 60/39.19, 431/4, 431/190
• US Class Current: 60/39.55
• CPC Class Codes: F01K 21/047 having at least one combustion gas turbine
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder

Abstract

A heat engine provides work output from a first working fluid operating in essentially a Brayton-type thermodynamic cycle and from a second working fluid operating essentially in a Rankine-type thermodynamic cycle, the two working fluids interacting with each other so that the work output of the two working fluids, working in parallel during the conversion of heat energy to work, is compounded.

Claims

1. A heat engine comprising:

a. first means for converting heat energy to mechanical work essentially according to the Brayton thermodynamic cycle, having a first working fluid resulting from combustion of a mixture of air and a hydrocarbon fuel in the ratio of from about 0.8 to 2.0 times the stoichiometric air/fuel ratio;

b. second means for converting heat energy to mechanical work essentially according to the Rankine thermodynamic cycle, having a second working fluid comprising water;

c. said first and second means operating in parallel with each other with means for intermixing said first and second working fluids with a ratio of water-to-air by weight in the range of about 0.2 to 1.0 so that the work output of each is compounded and said second working fluid contains greater heat content than said first working fluid, and

d. means for recuperating exhaust heat from said intermixed working fluid for pre-heating said second working fluid to the vapor or mixed liquid and vapor form prior to intermixing with the first working fluid.

9. A heat engine as in claim 1 including means for recovering and condensing back water into a liquid from said intermixed working fluid and means wherein non-soluble combustion products are exhausted and water-soluble combustion products are separately removed from the recovered water.

2. A heat engine comprising:

a. a combustion chamber;

b. compressor means for introducing a first reactant comprising air into said combustion chamber;

c. means for introducing a second reactant comprising a hydrocarbon fuel into said combustion chamber for combustion with said first reactant, and wherein the overall air/fuel ratio includes the range of about 0.8 to 2.0 times that of stoichiometric air/fuel ratio;

d. means for introducing water in the form of a vapor or a vapor/liquid mixture within said combustion chamber at a weight ratio of said water-to-air in the range of about 0.25 to 0.85 whereby the water vapor or vapor/liquid mixture is converted to super-heated vapor by heat transfer through rapid and turbulent mixing with the heated combustion products;

e. means responsive to the mixture of said superheated vapor and combustion products for converting the energy associated with the mixture to mechanical energy; and

f. means for transferring residual thermal energy from said mixture of super-heated vapor and combustion products to said water to thereby preheat the same to a vapor or vapor/liquid mixture prior to its introduction within said combustion chamber.

3. A heat engine as in claim 2 wherein said converting means comprises expander means which includes first and second expanders, and wherein said first expander drives said compressor means and wherein said second expander provides work output, and regulating valve means for providing a variable part of said mixture from said combustion chamber directly to said first expander and means for providing another variable part of said mixture directly to said second expander.

10. A heat engine as in claim 2. including means for recovering and condensing back water into a liquid from said mixture of said superheated vapor and combustion products and means wherein non-soluble combustion products are exhausted and water-soluble combustion products are separately removed from the recovered water.

4. A heat engine for converting heat energy to mechanical work comprising:

a. means for converting heat energy from combustion, in the range of about 0.8 to 2.0 times the stoichiometric ratio by weight, of a compressed mixture of air and a hydrocarbon fuel such that the combustion products comprise a first working fluid for the engine cycle;

b. means for converting heat energy by a second working fluid, comprising water, which receives a substantial amount of the heat energy of the first working fluid through turbulent intermixing and undergoes a phase change from vapor or a vapor/liquid mixture to superheated steam during the operation of the cycle;

c. means for expanding the two working fluids through a mechanical expander to do work;

d. means whereby the ratio of the second and first working fluids is above 0.2 by weight so that the second working fluid acquires greater heat content than the first working fluid; and

e. means for recuperating exhaust heat from said intermixed working fluid for pre-heating said second working fluid to the vapor or mixed liquid and vapor form prior to intermixing with the first working fluid.

5. A heat engine as in claim 4. wherein the ratio of the second to first working fluids is in the range of 0.2 to 1.0 by weight.

7. A heat engine as in claim 4 wherein the weight ratio of water to combustion products is about 0.2 to 1.0.

8. A heat engine as in claim 4. wherein the weight ratio of water to combustion products is about 0.25 to 0.85.

11. A heat engine as in claim 4. including means for recovering and condensing back water into a liquid from said intermixed working fluid and means wherein non-soluble combustion products are exhausted and water-soluble combustion products are separately removed from the recovered water.

6. A heat engine comprising:

a. a combustion chamber;

b. compressor means for introducing a first reactant comprising air into said combustion chamber;

c. means for introducing a second reactant comprising a hydrocarbon fuel under pressure into said combustion chamber for combustion with said first reactant wherein the ratio of the first reactant to the second reactant falls within the range of about 0.8 to 2.0 times the stoichiometric ratio by weight;

d. means of introducing a fluid comprising water in a vapor/liquid mixture state into the said heat engine combustion chamber at a ratio of water to the combustion products greater than about 0.2 by weight whereby the said water is converted into superheated steam by heat transfer through rapid and turbulent mixing with the heated combustion products;

e. expander means for converting the energy associated with the mixture to mechanical work;

f. means for utilizing part of the mechanical work generated by said expander means to power said compressor means;

g. means for extracting useful work from said expander means; and

h. means for transferring residual thermal energy from said mixture of super-heated vapor and combustion products to said water to thereby preheat the same to a vapor/liquid mixture prior to its introduction within said combustion chamber.

12. A heat engine as in claim 6. including means for recovering and condensing back water into a liquid from said mixture of said superheated vapor and combustion products and means wherein non-soluble combustion products are exhausted and water-soluble combustion products are separately removed from the recovered water.