Combined heat power system
A combined heat power system comprises a Rankine cycle, optionally an organic Rankine cycle, using a fluid both in gaseous phase and liquid phase. The Rankine cycle comprises—an evaporator for evaporating the fluid from liquid phase to gaseous phase, an expander for expanding the fluid in gaseous phase provided by the evaporator. The expander is suitable to transform energy from the expansion of the fluid in gaseous phase into mechanical energy, —a condenser for condensing the fluid from gaseous phase from the expander to liquid phase and—a liquid pump for pumping the fluid in liquid phase provided by the condenser to the evaporator. The system comprises a heat source providing exhaust gas. The exhaust gas provides thermal energy for evaporating the fluid from liquid phase to gaseous phase by the evaporator. The system further comprises a generator unit for converting mechanical energy from expander to electrical energy. The expander is a volumetric expander.
1. A combined heat power system comprising:
a Rankine cycle, said Rankine cycle using a fluid both in gaseous phase and liquid phase, said Rankine cycle comprising
an evaporator configured to evaporate the fluid from liquid phase to gaseous phase;
an expander configured to expand the fluid in gaseous phase provided by the evaporator, the expander being suitable to transform energy from the expansion of the fluid in gaseous phase into mechanical energy;
a condenser configured to condense the fluid from gaseous phase from the expander to liquid phase; and
a fluid pump configured to pump the fluid in liquid phase provided by the condenser to the evaporator;
a heat source that provides exhaust gas, said exhaust gas providing thermal energy to evaporate the fluid from liquid phase to gaseous phase by said evaporator,
a generator unit configured to convert mechanical energy from the expander to electrical energy to inject power into a grid or a battery, the expander being a volumetric expander, and
an oil pump configured to provide oil to the generator unit, the expander, and the fluid pump,
wherein said expander, said generator unit and said fluid pump are coaxially mounted so that the fluid pump is mounted below the expander.
2. The combined power system according to claim 1 , wherein said Rankine cycle uses an organic fluid.
3. The combined heat power system according to claim, 1 , wherein said heat source is a burner for burning biomass.
4. The combined heat power system according to claim 1 , wherein said volumetric expander comprises any of a vane expander, a reciprocal piston expander, a screw expander, a rolling cylinder expander, a positive displacement expander, a hypocycloid expander or a epicycloid expander.
5. The combined heat power system according to claim 1 , wherein said volumetric expander comprises a scroll expander.
6. The combined heat power system according to claim 1 , wherein said generator unit comprises a rotary generator.
7. The combined heat power system according to claim 6 , wherein said expander, said rotary generator and said fluid pump are mounted in one gas-tight unit.
8. The combined heat power system according to claim 1 , the generator being a permanent magnet generator.
9. The combined heat power system according to claim 8 , the generator being an axial flux permanent magnet generator dual rotor with a large number of poles and concentrated pole winding.
10. The combined heat power system according to claim 1 , wherein said generator unit further comprises a variable speed converter for converting the variable frequency of said generator unit to the grid frequency.
11. The combined heat power system according to claim 10 , wherein said converter is used to inject power into the grid or into a battery, wherein the converter comprises an AC to DC section based on a circuit using MOSFET and IGBT as controlled switches, where the MOSFET and IGBT are connected in series in each leg.
12. The combined power system according to claim 11 , wherein the MOSFET has a slow diode with large recovery charge but low switching losses, and the IGBT has a fast diode but more switching loss.
13. The combined heat power system according to claim 11 , wherein the MOSFET is used to switch at a higher frequency than the IGBT.
14. The combined heat power system according to claim 1 , wherein said system is part of a central heating system.
15. The combined heat power system according to claim 1 , wherein the oil pump is coaxially mounted with said expander, said generator unit and said fluid pump, and wherein said oil pump is mounted below the fluid pump.
16. The combined heat power system according to claim 1 , further comprising a fluid/oil separator coupled to the fluid pump, said fluid/oil separator configured to separate oil and the fluid so that the oil is guided to the generator, the expander, and fluid pump and the fluid is guided to the evaporator.
17. A combined heat power system comprising:
a Rankine cycle, said Rankine cycle using a fluid both in gaseous phase and liquid phase, said Rankine cycle comprising
an evaporator configured to evaporate the fluid from liquid phase to gaseous phase;
an expander configured to expand the fluid in gaseous phase provided by the evaporator, the expander being suitable to transform energy from the expansion of the fluid in gaseous phase into mechanical energy;
a condenser configured to condense the fluid from gaseous phase from the expander to liquid phase; and
a fluid pump configured to pump the fluid in liquid phase provided by the condenser to the evaporator;
a heat source that provides exhaust gas, said exhaust gas providing thermal energy to evaporate the fluid from liquid phase to gaseous phase by said evaporator, and
a generator unit configured to convert mechanical energy from the expander to electrical energy to inject power into a grid or a battery, the expander being a volumetric expander,
wherein said expander, said generator unit and said fluid pump are coaxially mounted so that the fluid pump is mounted below the expander, and
wherein said expander, said generator unit and said fluid pump are coaxially mounted inside a second heat exchanging unit.
18. A combined heat power system comprising:
a Rankine cycle, said Rankine cycle using a fluid both in gaseous phase and liquid phase, said Rankine cycle comprising
an evaporator configured to evaporate the fluid from liquid phase to gaseous phase;
an expander configured to expand the fluid in gaseous phase provided by the evaporator, the expander being suitable to transform energy from the expansion of the fluid in gaseous phase into mechanical energy;
a condenser configured to condense the fluid from gaseous phase from the expander to liquid phase; and
a fluid pump configured to pump the fluid in liquid phase provided by the condenser to the evaporator;
a heat source that provides exhaust gas, said exhaust gas providing thermal energy to evaporate the fluid from liquid phase to gaseous phase by said evaporator,
a generator unit configured to convert mechanical energy from the expander to electrical energy to inject power into a grid or a battery, the expander being a volumetric expander, and
a thermal oil heat exchanger configured to transfer heat from the heat source to thermal oil inside the thermal oil heat exchanger so that the thermal oil is configured to conduct heat to the fluid in the evaporator,
wherein said expander, said generator unit and said fluid pump are coaxially mounted so that the fluid pump is mounted below the expander.