A control system for controlling an adjustable output voltage provided to a heater includes a controller configured to determine an input parameter based on an electrical characteristic of the heater, where the heater includes a resistive heating element that is operable to emit heat and as a sensor. The controller is further configured to determine an output voltage for the heater based on the input parameter and a desired setpoint, and to transmit a signal to a power converter to generate the output voltage. The desired setpoint is based on an operational state of the heater, and the input parameter includes data indicative of a temperature of the resistive heating element that is determined based on the electrical characteristic.

The present invention relates to a method for controlling one or more heat pumps (110) connected to a distribution grid (10) for fluid-based distribution of heating and cooling in order to, at least partly, compensate for a cold outtake from the distribution grid (10) by a first cooling machine (120) connected to the distribution grid (10). Alternatively, or in combination, one or more cooling machines (120) connected to the distribution grid (10) may be controlled in order to, at least partly, compensate for a heat outtake from the distribution grid (10) by a first heat pump (120) connected to the distribution grid (10). The controlling is made a control server (200) monitoring outtake of heat and/or cold from the distribution grid (10) by the heat pumps (110) and cooling machines (120) connected to the distribution grid (10). The control server (120) generates and sends out control messages to the heat pumps and/or cooling machines.

High-efficient central chiller plant system with variable load by phase change material thermal energy storage, comprising a refrigeration unit and a phase change thermal energy storage. The refrigeration unit operates under the highest COP. If the refrigerating output is higher than the demand of cooling load, the phase change thermal energy storage stores energy by the phase change. Contrarily, if the refrigerating output cannot meet the demand of cooling load, the phase change thermal energy storage releases energy to supply the insufficient cooling load of the refrigeration unit. So that users can set the operation strategy of the refrigeration unit according to the usage statistics, and let the refrigeration unit operate efficiently with the cooperation of the phase change thermal energy storage, thereby effectively improving the energy efficiency of the system operation to save energy. Compared with the existing central chiller system, it saves energy more than 40%-70%.

A climate-control system may include a first working fluid circuit, a second working fluid circuit and a storage tank. The first working fluid circuit includes a first compressor and a first heat exchanger in fluid communication with the first compressor. The second working fluid circuit includes a second compressor and a second heat exchanger in fluid communication with the second compressor. The storage tank contains a phase-change material. The first working fluid circuit and the second working fluid circuit are thermally coupled with the phase-change material contained in the storage tank.

A climate-control system may include a first working fluid circuit, a second working fluid circuit and a storage tank. The first working fluid circuit includes a first compressor and a first heat exchanger in fluid communication with the first compressor. The second working fluid circuit includes a second compressor and a second heat exchanger in fluid communication with the second compressor. The storage tank contains a phase-change material. The first working fluid circuit and the second working fluid circuit are thermally coupled with the phase-change material contained in the storage tank.

The invention relates to an energy storage system for storing heat and coldness and for providing electrical energy, characterized by an energy converter, wherein the energy converter is designed to produce electrical energy from heat and coldness and to produce heat and coldness from electrical energy, the energy converter being in heat-transferring contact with a hot heat exchanger and with a cold heat exchanger, the hot heat exchanger being connected to a heat reservoir and the cold heat exchanger being connected to a coldness reservoir, and a control unit being provided, which operates the energy storage system in a first operating mode, in which heat and coldness are formed from electrical energy by means of the energy converter, and in a second operating mode, in which electrical energy is produced from heat and coldness.

In a split system heat pump cooling and heating system, an auxiliary hot water storage tank is provided as an energy storage bank. Two sets of coils run through this storage tank, a first set carrying hot refrigerant from the heat pump to deposit energy and a second set carrying hot potable water to remove energy. Valve and switch matrixes are operated at the heat pump to provide hot potable water from the energy storage bank during both normal space heating and cooling operations of the heat pump.

The present disclosure generally describes a system that includes a heater, a power converter including a power switch, and a controller. The power converter is in communication with the heater and is operable to apply an adjustable voltage to the heater. The controller is in communication with the power switch to control the voltage output of the power converter based on at least one of a load current and a detected voltage at the heater. The controller operates the power switch to adjust the voltage output of the power converter.

A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a heating fluid circuit, a cooling fluid circuit, and a storage fluid circuit. A thermal system of the HVACR system absorbs energy from the storage fluid circuit and rejects it to the heating fluid circuit. The storage fluid circuit includes thermal storage tanks containing thermal storage material that can provide energy for heating or absorb energy for cooling depending on the state of the thermal storage material. Heating can be provided using the heating fluid circuit and the heat provided by the thermal system. Cooling can be provided using the cooling fluid circuit by absorbing energy from the conditioned space using a cooling fluid and rejecting energy from the cooling fluid to the storage fluid circuit. The thermal storage tanks can have heat added to them using an air source heat pump system to support heating operations.

A method of heating water in a water storage tank. The method includes: selecting an outlet port and an inlet port from at least three ports located in the tank at different heights along a vertical direction. The outlet port is below the inlet port. The method further includes extracting water from the outlet port, supplying the extracted water to an external heat exchanger configured for heating the extracted water, and delivering heated water from the heat exchanger to the selected inlet port.