Abstract:
A closed-loop reheat circuit decoupled from a main refrigerant circuit is provided as part of a refrigerant system. In the closed-loop reheat circuit refrigerant is flown through an auxiliary heat exchanger, at which it transfers heat to refrigerant in the main circuit, increasing its cooling and dehumidification potential prior to entering an evaporator. The closed-loop circuit also includes a reheat heat exchanger that is placed in the path of at least a portion of airflow having passed over an evaporator. The reheat heat exchanger reheats air supplied to a conditioned space to a desired temperature after sufficient amount of moisture has been removed from the air in the evaporator to provide a comfortable humidity level. By utilizing the closed-loop reheat circuit, a control for the overall refrigerant system becomes less complex and more flexible, and the refrigerant system operation turns out to be more reliable and satisfying a variety of environmental conditions and potential applications. Various features and options of the decoupled reheat circuit concept are also disclosed.
Abstract:
A reciprocating compressor includes a cylinder block, a cylinder head, and a bypass unloader valve assembly. The cylinder block has a cylinder disposed therein. The cylinder head is secured to the cylinder block overlying the cylinder and has a suction plenum and a discharge plenum in selective fluid communication with the cylinder. The bypass unloader valve assembly is in operable communication with the cylinder head and is responsive to control signals to rapid cycle to allow for fluid communication of a refrigerant between the discharge plenum and the suction plenum.
Abstract:
A refrigerant vapor compression system includes a hot gas bypass line establishing refrigerant vapor flow communication between the compression device and the refrigerant heat absorption heat exchanger, and bypassing the refrigerant heat rejection heat exchanger and the primary expansion device. A refrigerant vapor flow control device is interdisposed in the hot gas bypass line. The flow control device has at least a first open position in which refrigerant vapor flow may pass through the hot gas bypass line and a closed position in which refrigerant vapor flow may not pass through the hot gas bypass line.
Abstract:
A reciprocating piston compressor for use in a refrigerant compression circuit comprises first and second intake manifolds, first and second reciprocating piston compression units, an outlet manifold and a first pulsing valve. The intake manifolds segregate inlet flow into the compressor. The first and second reciprocating piston compression units receive flow from the first and second intake manifolds, respectively. The outlet manifold collects and distributes compressed refrigerant from the compression units. The first pulsing valve is mounted externally of the first intake manifold to regulate refrigerant flow into the first intake manifold. In another embodiment, a second valve is mounted externally of the second intake manifold to regulate flow into the second intake manifold, and the first and second valves are operated by a controller. The controller activates the first valve with variable width pulses having intervals less than an operating inertia of the refrigerant compression circuit.
Abstract:
A modular multi-channel tube heat exchanger includes a plurality of aluminum heat exchanger modules selectively connected in fluid communication by interconnecting tubing. Each heat exchanger module includes an aluminum inlet header, an aluminum outlet header and a plurality of aluminum heat exchange tubes extending longitudinally therebetween. Each of the plurality of heat exchange tubes may have a plurality of flow paths extending longitudinally in parallel relationship from an inlet end thereof in fluid communication with the inlet header to an outlet end thereof in fluid communication with the outlet header.
Abstract:
A refrigerant system operates in an environment defined by three distinct temperature levels, such as, for instance, the outdoor ambient temperature level, the indoor temperature level and the refrigeration temperature level. The refrigerant system is provided with an air-to-refrigerant heat exchanger located within the general indoor environment and connected to receive the flow of refrigerant from a heat rejection heat exchanger. The air-to-refrigerant heat exchanger gives off heat to the indoor air and in the process further cools the refrigerant flowing to an expansion device to thereby increase the cooling effect provided by an evaporator to the refrigeration area. Provisions are also made to partially or entirely bypass the air-to-refrigerant heat exchanger and/or the heat rejection heat exchanger, on a selective basis.
Abstract:
A transport refrigeration/air conditioning system includes a fuel cell which is electrically connected to at least one of the compressor drive motor, evaporator fan motor or condenser fan motor to provide electrical power thereto.
Abstract:
A single speed compressor is provided with a switching device and control for turning the compressor drive motor ON and OFF in repeated succession at a selected ON time/OFF time ratio within a selected cycle time interval. The ON/OFF ratio and cycle time interval are selected to maintain desired temperature and/or humidity control within a conditioned space.
Abstract:
A refrigerant system is provided with at least two sequential stages of compression. An intercooler is positioned intermediate the two stages. The refrigerant flowing through the intercooler is cooled by a secondary fluid such as ambient air. A vapor/liquid injection function is also provided for the refrigerant system. The intercooler function and the vapor/liquid injection function are selectively activated on demand depending on environmental conditions and thermal load in a conditioned space. This invention is particularly important for the CO2 refrigerant systems operating in the transcritical cycle.
Abstract:
A refrigerant system includes a compressor that has safe operating limits that are also built into a refrigerant system control to protect the compressor. Under certain conditions, these safe operational limits may be changed to allow the compressor to operate beyond the safety limits at least for a period of time.