Onboard heater of auxiliary systems using exhaust gases and associated methods
An exhaust energy recovery system (EERS) and associated methods for an engine are disclosed. An embodiment of an EERS, for example, includes an inlet duct that is configured to divert exhaust gas from an exhaust duct of the engine into the recovery system and an outlet duct configured to return the exhaust gas to the exhaust duct downstream of the inlet duct. The recovery system is configured to heat components or fluids associated with engine to operating temperatures. The recovery system may be part of a mobile power system that is mounted to a single trailer and includes an engine and a power unit such as a high pressure pump or generator mounted to the trailer. Methods of operating and purging recovery systems are also disclosed.
1. A mobile power system comprising:
a transportation platform;
an engine mounted to the transportation platform, the engine having an intake port and an exhaust duct, the engine comprising a gas turbine engine;
a first heat distribution reservoir mounted to the transportation platform;
an exhaust energy recovery system (EERS) mounted to the transportation platform, the EERS comprising:
an inlet duct in communication with the exhaust duct, the inlet duct having an open configuration in which the inlet duct is configured to divert a first portion of an exhaust gas from the exhaust duct to a recovery flow path and allow a second non-zero portion of the exhaust gas of the exhaust duct to be exhausted, the inlet duct having a closed configuration in which the inlet duct is configured to prevent the exhaust gas from flowing to the recovery flow path,
an outlet duct in communication with the exhaust duct downstream of the inlet duct, the outlet duct configured to return the first portion of the exhaust gas from the recovery flow path to the exhaust duct,
a first heat exchanger disposed in the recovery flow path between the inlet duct and the outlet duct, the first heat exchanger associated with the first heat distribution reservoir, the first heat exchanger configured to:
receive the exhaust gas from the recovery flow path;
transfer heat from the received exhaust gas to a media of the first heat distribution reservoir within the first heat exchanger; and
return the received exhaust gas to the recovery flow path,
a flushing assembly including a flushing port in fluid communication with the recovery flow path, the flushing port configured to receive a fluid when the inlet duct is in the closed configuration, such that the fluid flows through the recovery flow path and exits the outlet duct to purge residue from the recovery flow path, and
a flow restrictor disposed in the recovery flow path between the inlet duct and the first heat exchanger, the flow restrictor configured to limit flow of the exhaust gas through the recovery flow path;
a second heat distribution reservoir disposed in the recovery flow path between the inlet duct and the outlet duct; and
a second heat exchanger associated with the second heat distribution reservoir and configured to:
receive the exhaust gas from the recovery flow path; and
transfer heat from the received exhaust gas to a media; and
return the received exhaust gas of the second heat exchanger to the recovery flow path.
2. The system according to claim 1 , wherein the EERS further includes a pressure relief valve having a first end in communication with the recovery flow path between the inlet duct and the first heat exchanger and a second end in fluid communication with the recovery flow path between the first heat exchanger and the outlet duct, the pressure relief valve configured to return the exhaust gas from the inlet duct to the outlet duct bypassing the first heat exchanger.
3. The system according to claim 1 , further comprising:
a manifold positioned upstream of the first heat exchanger and the second heat exchanger, the manifold configured to distribute exhaust gas from the inlet duct to the first heat exchanger and the second heat exchanger.
4. The system according to claim 3 , wherein the EERS further includes:
a first control valve in the recovery flow path between the manifold and the first heat exchanger, the first control valve configured to control flow of the exhaust gas from the manifold to the first heat exchanger; and
a second control valve in the recovery flow path between the manifold and the second heat exchanger, the second control valve configured to control flow of the exhaust gas from the manifold to the second heat exchanger.
5. The system according to claim 4 , wherein the first control valve comprises a thermostatically controlled valve, and wherein the first heat distribution reservoir includes a temperature sensor configured to detect a temperature of the media of the first heat distribution reservoir, the first control valve being configured to open in response to the temperature of the media of the first heat distribution reservoir being below a first predetermined temperature and configured to close in response to the temperature of the media of the first heat distribution reservoir being at or above a second predetermined temperature.
6. The system according to claim 1 , wherein the first heat distribution reservoir comprises a heat distribution element selected from a group consisting of an oil heater, a gearbox lubrication heater, a pump lubrication heater, a water heater, and a heat fan, and wherein the media is selected from a group consisting of water, oil, and air.
7. The system according to claim 1 , wherein the transportation platform comprises a single trailer.
8. The system according to claim 1 , further comprising a power unit driven by the engine, the power unit being a hydraulic fracturing pump.