Apparatus and method for producing sustainable power and heat

Abstract

An integrated system provides electricity and heat from solar, waste heat, biomass and fossil fuel energy. The system operates with a volatile organic working fluid that circulates in a variable speed heat engine type cycle, that is heated either to its boiling point, to a saturated state or above its boiling point, or to a superheated gas state, expanded through an expander, with working fluid injected therein such that the fluid exiting the expander is cooled in a condenser in thermal communication with a facility's domestic hot water, space heating or process heating systems, and circulated by a pump. Heat exchange loops define hot water production capability for use in a facility while a generator is coupled to the expander to produce electricity and is connected to the utility grid at fixed frequency and voltage in either a paralleling or island mode.

1 . An integrated system producing electricity and heat for a facility comprising:
 at least one heat source producing one of a saturated liquid or superheated vapor;   an expander heat engine, receiving one of a saturated liquid or a superheated vapor from said at least one heat source, and having ports for injection of subcooled volatile organic fluid into an expansion chamber of the expander such that said volatile organic fluid exiting said heat engine expander is in a saturated state;   a first circuit configured to transport said volatile organic working fluid, said first circuit in thermal communication with said heat source where heat transferred therefrom raises the temperature of said volatile organic working fluid to one of a saturated bi-phase state or a superheated gas state, said first circuit further comprising:
 said heat engine expander being driven by said volatile organic working fluid under heat and pressure producing mechanical power to an output shaft; 
 an alternator operatively coupled to said output shaft generating electricity; 
 a converter-controller, converting the electricity from said alternator into specified alternating current and controlling the operations of said system; 
 a heat exchanger in fluid communication with said expander reducing the temperature of said volatile organic working fluid, said volatile organic working fluid exiting said expander in a liquid state and transferring latent and specific heat of said volatile organic working fluid to said facility's heating system, domestic hot water system, and process heat system; and, 
 a variable speed pump pressurizing and circulating said volatile organic working fluid through said system, the speed of said pump responding to signals from said converter controller and determining the state of said volatile organic working fluid entering said expander, the amount of electricity produced versus thermal power produced by said system; 
   a second circuit in thermal communication between said variable speed pump and said expander and transporting said volatile organic working fluid exiting said pump to said expander such that said volatile organic working fluid exits said expander in a saturated state, said second circuit further comprising:
 an injection valve dynamically controlling the flow of said volatile organic working fluid into said expander based on signals from said converter-controller. 
   
   
   
       2 . An integrated combined heat and electricity system according to  claim 1 , wherein said heat source is at least one solar collector directly heating said working fluid. 
   
   
       3 . An integrated combined heat and electricity system according to  claim 2 , wherein said heat source includes waste heat from said facility's air conditioning or refrigeration system, said facility's attic space, or said facility's process heat. 
   
   
       4 . An integrated combined heat and electricity system according to  claim 1 , wherein said heat source is a combustion burner consuming one of fossil fuel or biomass fuel. 
   
   
       5 . An integrated combined heat and electricity system according to  claim 4 , wherein said heat source is a fossil fuel combustion burner. 
   
   
       6 . An integrated combined heat and electricity system according to  claim 5 , wherein said volatile organic working fluid is heated directly by said heat source. 
   
   
       7 . An integrated combined heat and electricity system according to  claim 1 , further comprising:
 said volatile organic working fluid being heated by one of at least one solar collector, waste heat from said facility's air conditioner, biomass fuel combustion, or fossil fuel combustion; and,   a transfer fluid transferring heat to said volatile organic fluid through said heat exchanger.   
   
   
       8 . An integrated combined heat and electricity system according to  claim 1 , wherein said volatile working fluid is heated by waste heat from another lo power generator system including an internal combustion generator, turbine, micro turbine, or fuel cell, said waste heat exceeding 200° F. 
   
   
       9 . An integrated combined heat and electricity system according to  claim 1 , wherein said first circuit includes a receiver downstream of said expander to provide a reservoir for cooled volatile organic working fluid and a head for said variable speed pump. 
   
   
       10 . An integrated combined heat and electricity system according to  claim 1 , wherein said expander is cooled by an evaporative cooling tower. 
   
   
       11 . An integrated combined heat and electricity system according to  claim 1 , wherein said first circuit includes an emergency bypass around said expander for said volatile organic working fluid. 
   
   
       12 . An integrated combined heat and electricity system according to  claim 1 , wherein said converter-controller compares temperature and pressure signals in said heating device and said expander to determine amount said organic working fluid is saturated and superheated and controls the amount of said working fluid injected and the speed of said pump to control the state of the working fluid entering said expander. 
   
   
       13 . An integrated combined heat and electricity system according to  claim 1 , wherein said converter-controller operates in an interconnecting paralleling mode and an island mode when an utility electric grid fails. 
   
   
       14 . A method for utilizing thermal energy for the production of mechanical power, electrical power, hot water, space heating or process heat for a facility by controlling the temperature, pressure and state of a volatile organic fluid entering and exiting an expander of a heat engine cycle comprising:
 a) circulating and substantially adiabatically pressurizing said volatile organic fluid through a heat engine system;   b) circulating a portion of the pressurized volatile organic fluid to a heat exchanger of said system;   c) circulating the balance of the pressurized volatile organic fluid to injectors that communicate directly with an expansion volume of said expander;   d) providing an external heat energy source and passing said external heat energy source in heat exchange relationship with said circulating volatile organic fluid;   e) transferring the heat from the external heat energy source in a substantially isobaric manner to the circulating volatile organic fluid to one of a saturated or superheated state;   f) further circulating the heated volatile organic fluid from the heater to said expander;   g) injecting the unheated portion of the pressurized volatile organic fluid into the expansion volume of the expander so that the volatile organic fluid exits the expander in a saturated state;   h) providing a flow path for the volatile organic fluid through the expander, substantially adiabatically expanding said volatile organic fluid and exhausting the combined mass flow of said volatile organic fluid from the expander;   i) passing thermal transfer fluid from one of the facility's domestic hot water system, space heating system or process heat system in a heat exchange relationship with said volatile organic fluid exiting the expander; wherein said volatile organic fluid from the expander is in saturation state at a temperature sufficient to transfer heat from said volatile organic fluid to one of the domestic hot water system, space heating system or process heat system, at a minimum delta temperature between said volatile fluid and the heat transfer media;   j) removing heat of condensation of said volatile organic fluid medium in substantially isobaric manner to create a liquid phase condensate at a saturation temperature approximating the minimum reliable approach difference above the lowest temperature of said coolant fluid;   k) returning the liquid phase condensate produced to circulation in said system;   l) controlling the saturation temperature and pressure of said volatile organic fluid leaving the heater in response to the dynamic temperatures and pressures of the thermal energy to the system, ambient conditions and electrical and thermal loads of the facility; and,   m) controlling the saturation temperature and pressure of said volatile organic fluid in response to load demands of the facility and the targeted temperatures of the domestic hot water system, the space heating system and the process heat system to foster the saturation conditions of said volatile organic working fluid medium permits condensation.   
   
   
       15 . The method of  claim 14 , wherein controlling the temperature, pressure and state of said volatile organic fluid entering the expander includes sensing changes in temperature of the heater and the temperature of volatile organic fluid and controlling the mass flow through heater and volatile organic fluid by controlling the circulation of said volatile organic fluid and pressurizing said volatile organic fluid. 
   
   
       16 . The method of  claim 14 , wherein controlling the temperature, pressure and state of the volatile organic fluid leaving the expander includes sensing changes in electrical and thermal loads of the facility and controlling the lo mass flow through heater and volatile organic fluid in response thereto. 
   
   
       17 . The method of  claim 14 , wherein controlling the temperature, pressure and state of the volatile organic fluid entering the expander includes sensing changes in temperature of a condenser and the temperature of said volatile organic fluid and controlling the mass flow through a condenser and volatile organic fluid in response to the sensed changes in said fluid temperatures. 
   
   
       18 . The method of  claim 14 , wherein controlling the temperature, pressure and state of the volatile organic fluid leaving the expander from the heater comprising sensing changes in electrical and thermal loads of the facility and controlling the mass flow through heater and volatile organic fluid in response to the sensed changes in facility electrical and thermal loads. 
   
   
       19 . The method of  claim 14 , wherein controlling the mass flow to the expander comprises providing valve controlled injectors which introduce mass flow quantities of one of liquid, vapor or biphase volatile organic fluid into an expansion volume for mixing with the vapor phase fluid in transit therethrough, said valve controlled injectors locating along the travel path through the turbine. 
   
   
       20 . The method of  claim 14  wherein said external heat source includes at least one solar collector. 
   
   
       21 . The method of  claim 20  wherein the external heat source includes waste heat recovered from one of said facility's air conditioner or refrigeration equipment, attic, or other process waste heat. 
   
   
       22 . The method of  claim 21  wherein the external heat source includes heat from a separate heat engine system.