3964 results about "Economizer" patented technology

A refrigerant system is provided where the functions of an economizer heat exchanger and liquid-suction heat exchanger are combined. The two configurations are disclosed with a single common heat exchanger construction. In a first configuration, a series of valves selectively routes only one of two possible refrigerant flows through a common heat exchanger such that a control can selectively activate either an economizer heat exchanger circuit or a liquid-suction heat exchanger function. In a second configuration, both refrigerant flows are passed to the common heat exchanger through separate fluid lines and are selectively activated by the control. Variations of the second configuration are also disclosed.

In various illustrative examples, the system may include heat recovery heat exchangers, one or more turbines or expanders, a desuperheater heat exchanger, a condenser heat exchanger, a separator, an accumulator, and a liquid circulating pump, etc. In one example, a bypass desuperheater control valve may be employed. The system comprises a first heat exchanger adapted to receive a heating stream from a heat source after passing through a second heat exchanger and a second portion of a working fluid, wherein, the second portion of working fluid is converted to a hot liquid via heat transfer. An economizer heat exchanger that is adapted to receive a first portion of the working fluid and the hot discharge vapor from at least one turbine may also be provided. The first and second portions of the working fluid are recombined in a first flow mixer after passing through the economizer heat exchanger and first heat exchanger, respectively. A second heat exchanger is provided that receives the working fluid from the first flow mixer and a hot heating stream from a heat source and convert the working fluid to a hot vapor. The hot vapor from the second heat exchanger is supplied to at least one turbine after passing through a separator designed to insure no liquid enters the said at least one turbine or expander. The hot, high pressure vapor is expanded in the turbine to produce mechanical power on a shaft and is discharged as a hot, low pressure vapor.

An economizer-equipped refrigeration system and method is provided for simultaneous operation of at least one capacity control valve controlling an independent bypass circuit with operation and variable control of the economizer circuit to permit efficient, flexible, and reliable variable system capacity control, without leakage that sacrifices system peak capacity.

Refrigerant system schematics are provided with enhanced humidity and temperature control of the air supplied to an environment to be conditioned. In particular, an economizer cycle is incorporated to be utilized in a combination with a reheat coil. Proposed system configurations enhance system performance characteristics, offer more steps of unloading, especially in the reheat mode of operation, and operate at improved reliability. Additionally, due to the enhanced performance of the economizer cycle, the reheat coil size can be reduced.

An energy-reducing method and apparatus for retrofitting a constant volume HVAC system, with or without an economizer, that provides heating, cooling, and ventilation to occupants within a building space. The present invention includes the introduction of a programmable logic controller and variable frequency drive (VFD) that takes control of the existing fan, heating, cooling, and optional economizer operation. The controller is programmed for the reduction of fan speed in the heating and cooling modes. The reduction of the fan speed in the ventilation mode when the 100% operation is not needed saves significant energy of the existing constant volume HVAC system where the fan motor is designed to run 100% of the time. The fan speed may be further reduced upon a reduction in sensed occupancy levels of the space, such as with a CO2 sensor. Additionally, the fan speed may be reduced in the heating and / or cooling mode to further reduce energy consumption. The controller may also be programmed and equipped with sensors to allow simultaneous mechanical compressor cooling and economizer free cooling operation, for the operation of the economizer in response to the monitoring of outside air and return air to determine the preferred source for cooling operations, to keep the outside air damper closed during the unoccupied heating modes such as morning warm-up, and / or to provide fault detection. The retrofit method and apparatus may be employed in a stand-alone or networked version.