US 7,284,709 B2 · System and method for hydronic space heating with electrical power generation

Abstract

This invention provides a system and method for cogeneration of electric power and building heat that efficiently interfaces a liquid-cooled electric power generator with a multi-zone forced hot water (hydronic) space heating system. The system and method utilizes an electric generator with an electric output capacity (kW) that is near the time-averaged electric power consumption rate for the building and with a heat generation capacity that is useful for meeting building heating needs. This generator is operated as the priority source of heat for the building, but normally only when there is a demand for heat in building, with the intent of running the generator for long periods of time and generating a total amount of electric energy (kWhs) that is significant in comparison to the total electric energy consumption of the building over time. The actual onsite time-variable power demand (kW) is met by a combination of the cogenerated electric power produced on site and quantities of electric power from the public electric power grid or another external power source. Hence, useful electric power is generated on site as a by-product of the required generation of heat for space or water heating. The generator is run at a speed/operating condition that is appropriate to maintaining a long operational life.

Claims32

Dependent claims

A system for the space-heating of a building to a desired temperature and generation of electrical power comprising:

a fuel-burning electric power generator being electrically connected to the building electrical service, the electric power generator being constructed and arranged to transfer heat produced by an engine of the electric power generator therefrom to a first circulating liquid stream;
a heat exchanger for transferring said heat from said first circulating liquid stream into a second circulating liquid stream that delivers heat to different locations within the building
an auxiliary heater located in the second circulating liquid stream so as to transfer additional heat to the second circulating liquid stream, the auxiliary heater being heated by an auxiliary heat source separate from and not thermally connected to the electric power generator;
and
a control module that operates a first circulating pump for driving the first circulating liquid stream and a second circulating pump for driving the second circulating liquid stream, the electric power generator, auxiliary heater, and flow control components in the second circulating liquid stream to maintain the desired building temperature while optimizing the utilization of the electric power generator as a source of heat for the building.

2 more elements

A method for space heating a building and generating electric power for the electrical service of the building in conjunction with an external electric power source that is also interconnected with the building electrical service comprising:

operating a liquid-cooled electric power generator at a continuous running rated output level to deliver electricity to the electrical service when a request for space heat is made;
while operating the electric power generator, circulating coolant from the electric power generator to a primary heat exchanger interconnected with a hydronic heating circuit so as to transfer heat from the coolant to the hydronic heating circuit;
operating an auxiliary heater inline with the hydronic heating circuit when heat transferred from the primary heat exchanger is insufficient to provide desired space heat to the building;
and
controlling operation of the primary heat exchanger and the auxiliary heater to:
(a) first exclusively operate the primary heat exchanger to transfer heat to the hydronic heating circuit, and
(b) if space heat demand cannot be satisfied by (a), then operate the auxiliary heater in combination with the primary heat exchanger to transfer the additional heat to the hydronic heating circuit.

4 more elements

Dependencies are inferred from the claim text.

System and method for hydronic space heating with electrical power generation

Life of this patent

System and method for hydronic space heating with electrical power generation

Life of this patent

Abstract

Claims32