Abstract: An active charge control (ACC) in an air conditioner has a first portion of refrigerant passing into a compressor and a second portion held within the ACC. The first portion is substantially vapor and the second portion substantially liquid. Lubricant is included in both portions for lubricating the compressor. A lubricant mechanism includes a heat exchanger having a primary pathway thermally connected with the compressor and a secondary pathway operable between the ACC and the compressor. The secondary pathway transfers the refrigerant second portion to the compressor. The fluid inlet of the compressor retains liquid refrigerant. The secondary pathway delivers the refrigerant and the lubricant from the ACC to the compressor such that heat energy from the primary pathway is transmitted to the liquid refrigerant and lubricant in the secondary pathway evaporating the refrigerant in the secondary pathway such that refrigerant vapor and lubricant are sent to the compressor.

Abstract: A refrigerant system includes a compressor, an evaporator, an expansion valve, an accumulator or equivalent, one or more earth loops, and auxiliary heat removal means. The auxiliary means comprises a fan and fan coil and the fan forces air between multiple tubes of the fan coil to remove unwanted heat from the hot vapor exiting the compressor.

Abstract: A cooling system for PV cells includes an evaporator configured to thermally contact the PV cells and transfer heat generated thereby to coolant in the evaporator, a condenser for receiving vaporized coolant from the evaporator and condensing the coolant to a liquid state, tubing connecting the evaporator, and the condenser in a circuit, a compressor arranged in the circuit for pumping coolant therethrough in a coolant flow direction, an active charge control apparatus arranged in the circuit between, in the coolant flow direction, the evaporator and the condenser, and a liquid flow control apparatus arranged in the circuit between, in the coolant flow direction, the condenser and the evaporator. The active charge control apparatus and the liquid flow apparatus cooperate to maintain the evaporator completely wetted by coolant and prevent coolant in the liquid state from leaving the evaporator.

Abstract: A subcool flow control valve useful in a refrigerant system includes an enclosure having a fluid flow pathway for a controlled fluid between an inlet and an outlet. A thermally conductive flexible wall forms a sealed cavity within the enclosure for carrying a controlling fluid. A metering orifice operable between the pathway and the outlet port controls an amount of metered fluid passing through the outlet port in response to movement of the flexible wall toward and away from the metering orifice in response to temperature changes of the controlled fluid transmitting temperature and thus pressure changes to the controlling fluid in the sealed cavity. Inverse thermal feedback means is formed as part of the valve for stabilizing valve operation thus providing means for transmitting a thermal signal from the metered controlled fluid back to the controlling fluid.

Abstract: An active charge control (ACC) in an air conditioner has a first portion of refrigerant passing into a compressor and a second portion held within the ACC. The first portion is substantially vapor and the second portion substantially liquid. Lubricant is included in both portions for lubricating the compressor. A lubricant mechanism includes a heat exchanger having a primary pathway thermally connected with the compressor and a secondary pathway operable between the ACC and the compressor. The secondary pathway transfers the refrigerant second portion to the compressor. The fluid inlet of the compressor retains liquid refrigerant. The secondary pathway delivers the refrigerant and the lubricant from the ACC to the compressor such that heat energy from the primary pathway is transmitted to the liquid refrigerant and lubricant in the secondary pathway evaporating the refrigerant in the secondary pathway such that refrigerant vapor and lubricant are sent to the compressor.

Abstract: A heat pump apparatus maintains a desired constant amount of subcooling at an outlet of a condenser and a desired constant amount of superheat at an outlet of an evaporator, thereby requiring a charge defining level of refrigerant within a refrigerant storage container. A refrigerant level indicator is provided for indicating a level of liquid refrigerant to reside stored within the refrigerant container during operation of the heat pump. The superheat at an outlet of the evaporator is preferably controlled to be near zero degrees Fahrenheit so that the evaporator is fully flooded. Subcooling at an outlet of the condenser may also desirably be maintained at about zero degrees Fahrenheit. The refrigerant level indicator may be provided by a view port connected to the refrigerant container for permitting viewing of a level of liquid refrigerant. A liquid level sensor and associated display may also be used to indicate the level of refrigerant within the refrigerant container.

Abstract: A heat pump apparatus includes a start assist valve for permitting refrigerant to flow from an outlet of a condenser to an inlet of an evaporator during start-up of the heat pump apparatus. The heat pump apparatus preferably includes an expansion orifice connected in fluid communication between the outlet of the condenser and the inlet of the evaporator. The start assist valve provides a bypass for refrigerant flow around the expansion orifice during start-up of the heat pump apparatus. The apparatus also preferably includes a series of check valves cooperating with the start assist valve so that the start assist valve is operable only when the heat pump apparatus is in the cooling mode. The invention is particularly applicable to a direct expansion heat pump apparatus where one or more earth tap heat exchangers serve as the condenser when operating in the cooling mode.

Abstract: A heat pump apparatus includes a liquid refrigerant flow control valve connected in fluid communication between a condenser and evaporator. The liquid flow control valve includes a refrigerant outlet tube connected in fluid communication with an expansion orifice and extends in thermal contact with an upper portion of the valve housing for controlling condensing of vapor refrigerant within the housing to thereby stabilize refrigerant flow. A float, movably positioned within the housing, cooperates with the expansion orifice for controlling a flow of refrigerant passing from the housing to the evaporator based upon a level of liquid refrigerant within the housing. When a large amount of vapor refrigerant arrives at the liquid flow control valve as a result of a control oscillation or system disturbance, the float moves downwardly, thereby reducing flow through the expansion orifice, cooling the outlet tube and causing vapor to condense more quickly in the housing.

Abstract: A ground-coupled direct expansion heat pump apparatus includes an earth tap heat exchanger including a plurality of earth contacting tubes connected together in side-by-side relation. A first earth contacting tube defines a vapor refrigerant passageway and a second earth contacting tube provides additional heat transfer with the first earth contacting tube. Moreover, the earth tap heat exchanger includes a liquid refrigerant insulated passageway positioned within the second earth contacting tube. Each of the earth contacting tubes preferably comprises a thermal conductor, such as copper or a non-metallic material suitable for contact with refrigerant, to transfer heat with surrounding earth and with an adjacent earth contacting tube. The liquid refrigerant passageway and the vapor refrigerant passageway are preferably connected together in fluid communication adjacent lower ends thereof. Multiple vapor refrigerant passageways may be provided by additional earth contacting tubes.

Abstract: A method for identifying a leaking earth tap heat exchanger includes measuring an electrical resistance between the electrically conducting tubing of the earth tap heat exchanger and the surrounding soil or water to determine if the electrically insulating layer has an undesired opening in a portion thereof thereby exposing an adjacent portion of the electrically conducting tubing to the soil or water as indicated by a relatively low electrical resistance. Each earth tap heat exchanger preferably comprises electrically conducting tubing having an electrically insulating layer covering an exterior thereof. The method may also be used to test the integrity of the electrically insulating layer to avoid corrosion as may be caused by direct contact between metallic tubing and adjacent soil or water. Apparatus aspects of the invention are also disclosed.

Abstract: A nonlinear processor for an echo canceller has an adaptive suppression threshold which is a function of an echo estimate signal generated by an adaptive filter. The nonlinear processor also has an adaptive noise transparency threshold which is a function of an estimated level of background noise. The nonlinear processor is in the send path at the near end of a 4-wire circuit, and during far end single talk is activated to pass send path signals that are below the noise transparency threshold level and above the suppression threshold level. The dual adaptive thresholds of the nonlinear processor during far end single talk result in removal of residual echo from the send path while allowing limited levels of actual background noise to remain on the send path to improve the perceived quality of the voice connections to a far end talker/listener.

Abstract: The heating system of the present invention includes a compressor for compressing and heating refrigerant. The pressurized, heated refrigerant is passed through a first heat exchanger which is coupled to a container of water. A pump circulates water from the container through the first heat exchanger to transfer heat from the refrigerant through the heat exchanger to the water. This heat exchange process cools and condenses the refrigerent from a gas to a liquid as the water is heated. The liquified refrigerant is transferred to a coaxial earth tap which includes an inner passageway for transferring the refrigerant from the upper end to the lower end of the earth tap and a restrictor positioned at the lower end of the tap for vaporizing the refrigerant.

Abstract: This disclosure describes an electrical and pneumatic device for picking fruit, particularly citrus fruit, by severing the fruit from its stem with an electrical current, or pulling the fruit from its stem pneumatically by applying a suction cup to the side of the fruit and physically pulling the fruit from its stem, or by using a combination of electrical current and pneumatic (vacuum) force to sever the fruit from its stem.