A combined cooling, heating and power system is formed by integrating a CO.sub.2 cycle subsystem, an ORC cycle subsystem, and an LNG cold energy utilization subsystem based on an SOFC/GT hybrid power generation subsystem. The combined system can achieve efficient and cascade utilization of energy and low carbon dioxide emission. An SOFC/GT hybrid system is used as a prime mover. High-, medium-, and low-temperature waste heat of the system are recovered through CO.sub.2 and ORC cycles, respectively. Cold energy (for air conditioning and refrigeration), heat, power, natural gas, ice, and dry ice can be provided by using LNG as a cold source of the CO.sub.2 and ORC cycles. Low CO.sub.2 emission is achieved by condensation and separation of CO.sub.2 from flue gas, so energy loss of the system can be reduced, and efficient and cascade utilization of energy can be achieved, thereby realizing energy conservation and emission reduction.

A combined cooling, heating and power system is formed by integrating a CO.sub.2 cycle subsystem, an ORC cycle subsystem, and an LNG cold energy utilization subsystem based on an SOFC/GT hybrid power generation subsystem. The combined system can achieve efficient and cascade utilization of energy and low carbon dioxide emission. An SOFC/GT hybrid system is used as a prime mover. High-, medium-, and low-temperature waste heat of the system are recovered through CO.sub.2 and ORC cycles, respectively. Cold energy (for air conditioning and refrigeration), heat, power, natural gas, ice, and dry ice can be provided by using LNG as a cold source of the CO.sub.2 and ORC cycles. Low CO.sub.2 emission is achieved by condensation and separation of CO.sub.2 from flue gas, so energy loss of the system can be reduced, and efficient and cascade utilization of energy can be achieved, thereby realizing energy conservation and emission reduction.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A flow of working fluid may be adjusted to a percentage sufficient to maintain temperature of the flow of compressed gas within the selected operating temperature range.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A flow of working fluid may be adjusted to a percentage sufficient to maintain temperature of the flow of compressed gas within the selected operating temperature range.

A combined heat and power system, or an energy system, is provided. A four-stroke opposed-piston engine provides efficient power from a generator set or genset. A heat exchange system is provided within the energy system to provide efficient waste heat recovery as the engine is operated.

A combined heat and power system, or an energy system, is provided. A four-stroke opposed-piston engine provides efficient power from a generator set or genset. A heat exchange system is provided within the energy system to provide efficient waste heat recovery as the engine is operated.

Power is produced by operating first and second nested cycles utilising CO.sub.2 as working fluid without mixing of working fluid between the nested cycles. The first cycle comprises a semi-open loop operating under low pressure conditions in which CO.sub.2 is sub-critical. The second cycle comprises a closed loop operating under higher pressure conditions in which CO.sub.2 is supercritical. The first cycle operates in a Brayton cycle including oxycombustion of hydrocarbons, preferably LNG, in a combustion chamber under low pressure conditions, expansion for power production to provide a first power source, cooling in a recuperator, compression, reheating by counter-current passage via the recuperator, and return of working fluid heated by the recuperator back to the combustion chamber. Water and excess CO.sub.2 resulting from the oxycombustion step are separated from the first cycle. The first cycle serves as a source of heat for the second cycle by gas/gas heat exchange in a gas/gas heat exchanger which results in cooling of the products of combustion and circulating working fluid in the first cycle and heating of working fluid in the second cycle. The second cycle is operated in a Brayton cycle including heating of working fluid in the second cycle by the gas/gas heat exchanger, expansion for power generation to provide a second power source, cooling in two-stages by first and second recuperator steps, compression, reheating by counter-current passage via the first recuperator step, and return of working fluid heated by the first recuperator step back to the gas/gas heat exchanger. Working fluid in the first cycle following the compression step is heated by working fluid in the second cycle by counter-current passage via the second recuperator step.

Power is produced by operating first and second nested cycles utilising CO.sub.2 as working fluid without mixing of working fluid between the nested cycles. The first cycle comprises a semi-open loop operating under low pressure conditions in which CO.sub.2 is sub-critical. The second cycle comprises a closed loop operating under higher pressure conditions in which CO.sub.2 is supercritical. The first cycle operates in a Brayton cycle including oxycombustion of hydrocarbons, preferably LNG, in a combustion chamber under low pressure conditions, expansion for power production to provide a first power source, cooling in a recuperator, compression, reheating by counter-current passage via the recuperator, and return of working fluid heated by the recuperator back to the combustion chamber. Water and excess CO.sub.2 resulting from the oxycombustion step are separated from the first cycle. The first cycle serves as a source of heat for the second cycle by gas/gas heat exchange in a gas/gas heat exchanger which results in cooling of the products of combustion and circulating working fluid in the first cycle and heating of working fluid in the second cycle. The second cycle is operated in a Brayton cycle including heating of working fluid in the second cycle by the gas/gas heat exchanger, expansion for power generation to provide a second power source, cooling in two-stages by first and second recuperator steps, compression, reheating by counter-current passage via the first recuperator step, and return of working fluid heated by the first recuperator step back to the gas/gas heat exchanger. Working fluid in the first cycle following the compression step is heated by working fluid in the second cycle by counter-current passage via the second recuperator step.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A flow of working fluid may be adjusted to a percentage sufficient to maintain temperature of the flow of compressed gas within the selected operating temperature range.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A flow of working fluid may be adjusted to a percentage sufficient to maintain temperature of the flow of compressed gas within the selected operating temperature range.