Abstract: An evaporator for a micro combined heat and power system. The evaporator includes a heat source, an enclosure made up of at least a heating chamber and a primary fluid flowpath, and tubing that intersects the primary fluid flowpath. In one embodiment, the heat source is a burner such that the primary fluid is an exhaust gas formed by a combustion process at the burner, and the primary fluid flowpath is for the transport of the exhaust gas. The tubing defines a secondary fluid flowpath with a proximal portion adjacent the heat source and a distal portion downstream in the flowpath from the proximal portion. Working fluid first flows through the distal portion in counterflow relationship with the exhaust gas, then flows through the proximal portion in co-flow relationship with the exhaust gas. This circuiting avoids the excessive working fluid temperature of traditional counterflow heat exchangers, while providing better heat transfer efficiency than traditional co-flow heat exchangers.

Abstract: A micro combined heat and power system includes at least a heat source, an expander, a pump, a staged, counterflow condenser and a conduit for transporting a working fluid. The heat source can be, for example, a burner, while the expander is preferably a scroll expander. The heat source superheats the working fluid, which is preferably an organic working fluid. The superheated organic working fluid passes through the expander, which is coupled to a generator to produce electricity. After the working fluid is expanded, its gives up at least a portion of its excess heat first to the condenser. By placing the condenser in a counterflow arrangement, the fluid receiving the heat from the condensing working fluid can be of a higher temperature, thus allowing more system variation in the heat to power output ratio. The fluid receiving heat from the condenser may include circulating air, water or related fluid to provide space heat or domestic hot water.

Abstract: A waffle baker is disclosed which is of tubular frame construction having a pair of shell members which have a food receiving part, a handle, and a hinge. The shell members include a heater coil for connecting to a power source and a thermocouple to monitor the heat index of the shell members. A timing system is incorporated into the system, preferably through a magnetic and proximity switch, such that the baker turning and cooking time is monitored with either visual and/or audio warnings.

Abstract: Apparatus for recovering refrigerant from a refrigeration system having a high pressure liquid side and a low pressure vapor side comprises a storage receptacle for receiving recovered refrigerant, a liquid flow circuit for recovering liquid from the high pressure side of the system, a vapor flow circuit for recovering vapor from the low pressure side of the system, and a vapor feedback flow circuit from the receptacle to the inlet side of a vapor reducing section of the vapor flow circuit. The apparatus is operable in a liquid recovery mode and in a vapor recovery mode, and an arrangement for automatically purging non-compressible gases from liquid refrigerant is provided in the vapor flow circuit on the downstream side of the vapor reducing section thereof.