An energy efficient heat pump for a heating, ventilation, and air conditioning (HVAC) system includes a vapor compression circuit, a heat exchanger of the vapor compression circuit configured to place a working fluid in a heat exchange relationship with an air flow directed across the heat exchanger, and a conduit system of the vapor compression circuit. The conduit system of the vapor compression circuit is configured to direct the working fluid into the heat exchanger and to receive the working fluid from the heat exchanger, wherein the conduit system is configured to direct the working fluid into the heat exchanger to place the working fluid in a counterflow arrangement with the air flow directed across the heat exchanger in a cooling mode of the heat pump and in a heating mode of the heat pump.

A variable capacity screw compressor comprises a suction port, at least two screw rotors and a discharge port being configured in relation to a selected rotational speed that operates at least one screw rotor at an optimum peripheral velocity that is independent of a peripheral velocity of the at least one screw rotor at a synchronous motor rotational speed for a rated screw compressor capacity. A motor is configured to drive the at least one screw rotor at a rotational speed at a full-load capacity that is substantially greater than the synchronous motor rotational speed at the rated screw compressor capacity. A variable speed drive receives a command signal from a controller and generates a control signal that drives the motor at the selected rotational speed.

This present disclosure provides a compressor and a refrigeration device having the compressor. The refrigeration device has a coupling assembly and a frequency converter connected to one end of the coupling assembly. The compressor has a first shell and a permanent magnet motor. The permanent magnet motor is set in the first shell and connected to the other end of the coupling assembly. By designing the relevant parameters of the motor of the compressor, the efficiency of the motor and the compressor can be improved.

The present invention relates to a system and method for operational acoustic optimization of a variable speed compressor (2) comprising a synchronous motor (6), a frequency inverter (3) and a control block (5), such optimization being carried out by modifying the switching frequency of the supply signal (9) of the motor (6) contained in the compressor (2), via a control block (5), only during the aligmnent phase of the motor (6), thus, not impairing the performance of the compressor (2), the thermal management of the inverter (3) and the acoustic performance of the system.

In a power converter, an inductance L of a reactor and a capacitance C of a capacitor satisfy a condition of the expression (1) below. In the power converter, a current-limiting circuit between an AC power source and the capacitor is unnecessary. Herein, αm ([A.Math.s]) is a value of a ratio of a maximum rated current squared time product to a maximum rated output current of diodes of a rectifier circuit, Pmax is a maximum power consumption of the motor, Vac is a voltage value of a three-phase AC voltage, and a value of a constant a is 4.3 $\begin{array}{cc}a.Math.C.Math.\sqrt{\frac{C}{L}}.Math.\frac{{\mathrm{Vac}}^3}{P_{\max }}\le {\alpha }_m.& \left(1\right)\end{array}$

A water distribution apparatus and method including cold and hot water supplies, a fan coil (or chilled beam device), a control valve having cold and hot water inlets and outlets, cold and hot water outputs configured to supply cold and hot water to the fan coil, cold and hot water return inlets configured to receive from the fan coil the water supplied by the cold and/or water outputs and outputting the cold and/or hot water to the cold and hot water supply lines, respectively, via the cold and hot water outlets, respectively. Cold and hot water is supplied from the cold and/or hot water outputs to the fan coil and received into the cold and hot water return inlets, respectively, and the cold and hot water supplied by the cold and hot water outputs to the fan coil is output to the cold and hot water supply lines, respectively.

A chiller system includes a compressor, a condenser and an evaporator in fluid communication. A motor drives the compressor. A variable speed drive powers the motor. An oil heater and pump system circulate heated lubricating oil in the compressor. A control panel is arranged to determine whether an input parameter is greater than or equal to a threshold parameter; deactivate the VSD in response to sensing that the input parameter is less than the threshold parameter; determine at least one chiller capacity control parameter at a point when the VSD is deactivated, and maintain the at least one chiller capacity control parameter while the VSD is deactivated; determine that the input parameter has been restored; determine a motor rotation and motor rotational speed; and in response to determining that the input parameter is restored and the motor is rotating in a forward direction, reactivate the VSD.

Devices are provided for field weakening control of a compressor, including the compressor and a main circuit unit providing power for the compressor. The devices include a compressor rotational speed obtaining unit, and a control unit that compares the rotational speed ω of the compressor with a rotational speed threshold ω1 of the compressor, and controls the main circuit unit according to comparison results. When the rotational speed ω is less than ω1, an output voltage of the main circuit unit is controlled at a fixed value. When the rotational speed ω is greater than or equal to ω1, the compressor is controlled not to enter the field weakening control temporarily and the output voltage of the main circuit unit is controlled to rise, the compressor is controlled to enter the field weakening control when the output voltage of the main circuit unit cannot continue to rise.

An air conditioner includes a blower unit to blow air at a predetermined amount, a cooling unit arranged downstream of the blower unit in an air flowing direction, a compressor which is operated at a variable operating frequency so that a revolving speed thereof is adjustable, a condenser, and a cooling coil connected in this order by pipes to circulate a heating medium to cool blown air with a heating unit arranged on a downstream side of the cooling unit in the air flowing direction in which the blown air is heated by a heater, and a control unit controls the operating frequency of the compressor and includes a compressor control part which adjusts the revolving speed of the compressor such that the operating frequency of the compressor is decreased by a predetermined frequency when an output of the heating unit exceeds a first threshold value.

A driving device is used with a compressor including a motor including coils. The driving device drives the motor. The driving device includes an inverter connected to the coils, a connection switching unit to switch a connection state of the coils between a first connection state and a second connection state, a controller to control the inverter and the connection switching unit, and a compressor state detection unit to detect a state of the compressor. When the connection state of the coils is the first connection state, the controller controls the motor based on a first detection value detected by the compressor state detection unit and a first threshold. When the connection state of the coils is the second connection state, the controller controls the motor based on a second detection value detected by the compressor state detection unit and a second threshold.