Patents by Inventor Dah Y. Cheng

Dah Y. Cheng has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5323661
    Abstract: A means and method of design and installation of a pre-rotator ahead of an elbow are disclosed in order to eliminate or reduce elbow-induced turbulence in pipe flows. Experimental verification was conducted, and noise and pressure loss for flow around the elbow can be substantially reduced.
    Type: Grant
    Filed: December 11, 1992
    Date of Patent: June 28, 1994
    Inventor: Dah Y. Cheng
  • Patent number: 5235470
    Abstract: A reflecting surface which is open at least at one axial end and in an axial section conforms to an axial section through a geometric surface generated by rotating a parabolic curve about an axis normal to the parabola axes. An elongated source/sink extends along the axis of the reflecting surface and is at least partly enveloped by that surface.
    Type: Grant
    Filed: August 5, 1991
    Date of Patent: August 10, 1993
    Inventor: Dah Y. Cheng
  • Patent number: 5233826
    Abstract: A method of operation of an Advanced Cheng Cycle heat engine comprising: (a) initializing start conditions in the gas turbine engine and the heat recovery steam generator with the control system; (b) setting the control valve means for idle flow condition of the heat engine; (c) pressurizing the drum with the compressed gas source to approximately the desired operating pressure of the heat recovery steam generator; (d) starting the gas turbine engine from idle to full load as limited by maximum allowed turbine inlet temperature; and (e) throttling second working fluid flow rate with the control valve means and shutting off the compressed gas source, after the sensor system indicates that heat recovery steam generator pressure is higher than compressor discharge pressure.
    Type: Grant
    Filed: September 8, 1992
    Date of Patent: August 10, 1993
    Inventor: Dah Y. Cheng
  • Patent number: 5197509
    Abstract: A means and method of design and installation of a pre-rotator ahead of an elbow are disclosed in order to eliminate or reduce elbow-induced turbulence in pipe flows. Experimental verification was conducted, and noise and pressure loss for flow around the elbow can be substantially reduced.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: March 30, 1993
    Inventor: Dah Y. Cheng
  • Patent number: 5170622
    Abstract: A Cheng cycle, dual-fluid heat engine comprising a compressor for compressing a first working fluid, having a compressor outlet; a combustion chamber in fluid communication with the compressor outlet; a turbine having an inlet in fluid communication with the combustion chamber for performing work by expansion of working fluid, and a turbine exhaust. The engine also has a heat recovery exchanger coupled to the turbine exhaust for heating thereby, having a heat recovery exchanger inlet and an outlet for heating a second working fluid; and an injector for introducing heated second working fluid from the heat recovery exchanger into the turbine. The engine has a coolant inlet port for introducing coolant having a temperature less than the first working fluid temperature at the compressor outlet, to at least one of turbine nozzles and blades in the turbine.
    Type: Grant
    Filed: April 2, 1991
    Date of Patent: December 15, 1992
    Inventor: Dah Y. Cheng
  • Patent number: 5165452
    Abstract: A design concept and method for a diverter which enables a diffuser to obtain pressure recovery at a very large expansion angle to be comparable to those with less than 15.degree. expansion angle diffusers.
    Type: Grant
    Filed: July 12, 1990
    Date of Patent: November 24, 1992
    Inventor: Dah Y. Cheng
  • Patent number: 5165373
    Abstract: A concept of pulse input thermal energy to induce a rapid volume change in a vessel is introduced to provide rapid pressure raise as a means to inject fuel into internal combustion engines. A computer and sensor means are incorporated to provide pulse width, height and multiple pulse using engine conditions such as RPM, exhaust pollution and efficiency, etc. as control parameters.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: November 24, 1992
    Inventor: Dah Y. Cheng
  • Patent number: 5037191
    Abstract: An Orthogonal Parabolic Reflector is generated by rotating a parabolic curve 90.degree. to the axis of symmetry passing through the focal point of the parabola. The Orthogonal Parabolic Reflector can concentrate a section of the linear source or sink on the axis of rotation to the focal point, resulting in integrating the intensity as a point source or sink at the focal point with almost no physical dimension effects.
    Type: Grant
    Filed: December 21, 1989
    Date of Patent: August 6, 1991
    Inventor: Dah Y. Cheng
  • Patent number: 4823546
    Abstract: A steam-injected free-turbine type of gas turbine is disclosed. In order to avoid the necessity of redesigning the compressor/core turbine, the shaft of the core turbine is modified to provide additional load output. As steam is injected into the system the resulting excess power of the core turbine is taken out of the system by coupling the compressor output shaft with a load. Thus, the core turbine operates as a single shaft turbine in addition to the existing power turbine. A control provides control of the load output of the two turbine output shafts so that the compressor/turbine stays in the matched operating domain.
    Type: Grant
    Filed: April 13, 1988
    Date of Patent: April 25, 1989
    Assignee: International Power Technology
    Inventor: Dah Y. Cheng
  • Patent number: 4790269
    Abstract: An improved procedure for cold start-up of closed loop boiler set and Cheng cycle system wherein the venting step, the boiler swelling problem and blowdown step of the conventional start-up are eliminated by use of an external pressure source to increase the operating pressure in the evaporator section which minimizes premature phase change and accompanying volume increase.
    Type: Grant
    Filed: April 4, 1988
    Date of Patent: December 13, 1988
    Assignee: International Power Technology, Inc.
    Inventors: James Hamill, Ramarao Digumarthi, William Conlon, Dah Y. Cheng, Chung-Nan Chang
  • Patent number: 4735043
    Abstract: An improved procedure for cold start-up of closed loop boiler set and Cheng cycle system wherein the venting step, the boiler swelling problem and blowdown step of the conventional start-up are eliminated by use of an external pressure source to increase the operating pressure in the evaporator section which minimizes premature phase change and accompanying volume increase.
    Type: Grant
    Filed: July 8, 1985
    Date of Patent: April 5, 1988
    Assignee: International Power Technology
    Inventors: James Hamill, Ramarao Digumarthi, William Conlon, Dah Y. Cheng, Chun-Nan Chang
  • Patent number: 4685288
    Abstract: An apparatus which automatically removes the non-condensable gases from the process steam cogenerated in the Cheng cycle system.
    Type: Grant
    Filed: November 20, 1986
    Date of Patent: August 11, 1987
    Assignee: International Power Technology
    Inventor: Dah Y. Cheng
  • Patent number: 4680927
    Abstract: A control system is disclosed for controlling Cheng dual-fluid cycle engines over a wide operating range to maintain high efficiency under partial load conditions.
    Type: Grant
    Filed: July 25, 1985
    Date of Patent: July 21, 1987
    Assignee: International Power Technology, Inc.
    Inventor: Dah Y. Cheng
  • Patent number: 4597256
    Abstract: An improved shutdown procedure, which minimizes the potential for steam condensation in the superheater section, combustion chamber and turbines during the coast to halt of the engine maintains high temperatures until all the steam has passed through the system.
    Type: Grant
    Filed: April 16, 1985
    Date of Patent: July 1, 1986
    Assignee: International Power Technology, Inc.
    Inventors: James Hamill, Ramarao Digumarthi, William Conlon, Dah Y. Cheng, Chun-Nan Chang
  • Patent number: 4549397
    Abstract: A control system is disclosed for controlling Cheng dual-fluid cycle engines over a wide operating range to maintain high efficiency under partial load conditions.
    Type: Grant
    Filed: March 18, 1983
    Date of Patent: October 29, 1985
    Assignee: International Power Technology, Inc.
    Inventor: Dah Y. Cheng
  • Patent number: 4499721
    Abstract: A control system is disclosed for controlling Cheng dual-fluid cycle engines over a wide operating range to maintain high efficiency under partial load conditions.
    Type: Grant
    Filed: March 21, 1983
    Date of Patent: February 19, 1985
    Assignee: International Power Technology, Inc.
    Inventor: Dah Y. Cheng
  • Patent number: 4476024
    Abstract: A composite membrane structure is used in a distillation apparatus and method. The composite membrane separates a distilland and a distillate, such as salt water and fresh water. The composite membrane comprises a thin lyophobic microporous layer or membrane and a thin lyophilic layer or membrane. Evaporation and condensation takes place within the micropores of the lyophobic membrane. The lyophilic layer prevents intrusion of distilland into the pores of the lyophobic layer.
    Type: Grant
    Filed: August 9, 1982
    Date of Patent: October 9, 1984
    Assignee: International Power Technology, Inc.
    Inventor: Dah Y. Cheng
  • Patent number: 4419242
    Abstract: A composite membrane separates a distilland and a distillate, such as salt water and fresh water. The composite membrane comprises a thin lyophobic microporous layer or membrane and a thin lyophilic layer or membrane on both sides of the lyophobic membrane or on the distillate side. Evaporation and condensation takes place within the micropores of the lyophobic membrane. The lyophilic layer on the distilland side prevents intrusion of distilland into the pores of the lyophobic layer. The lyophilic layer on the distillate side changes the surface curvature of the liquid/vapor interface in a manner which enhances the distillation rate through the membrane.
    Type: Grant
    Filed: February 18, 1982
    Date of Patent: December 6, 1983
    Assignee: International Power Technology, Inc.
    Inventors: Dah Y. Cheng, Steve J. Wiersma
  • Patent number: 4419187
    Abstract: Apparatus and method for improved thermal membrane distillation utilizes a composite membrane comprised of a microporous lyophobic layer having deposited thereon an essentially nonporous lyophilic coating.
    Type: Grant
    Filed: March 4, 1982
    Date of Patent: December 6, 1983
    Assignee: International Power Technology, Inc.
    Inventors: Dah Y. Cheng, Steve J. Wiersma
  • Patent number: 4417438
    Abstract: A control system is disclosed for controlling Cheng dual-fluid cycle engines over a wide operating range to maintain high efficiency under partial load conditions.
    Type: Grant
    Filed: June 12, 1981
    Date of Patent: November 29, 1983
    Assignee: International Power Technology, Inc.
    Inventor: Dah Y. Cheng