In a gamma free-piston Stirling cooler driven by linear electric motors, a motor operating frequency for consuming minimum electric power is detected and a different motor operating frequency that delivers maximum thermal cooling power is detected. The frequencies are detected by varying the operating frequency in small steps while sensing (1) the motor power input to maintain a steady temperature or (2) the thermal cooling power of the Stirling cooler. A mode detection routine detects whether the appropriate freezer operation is the electric power minimization mode or the thermal cooling power maximization mode based upon the current thermal conditions in the freezer. When the freezer is sufficiently cold, the pistons of the Stirling cooler are driven at the minimum electric power consumption frequency. When the temperature is, or is likely to become, too warm, the pistons of the Stirling cooler are driven at the maximum thermal cooling power frequency.

Disclosed is a transport refrigeration system including: an engine that is dedicated to the transport refrigeration system; a primary battery that is dedicated to the transport refrigeration system, the primary battery being electrically connected to the engine; and a jumper battery electrically connected to the primary battery, the jumper battery configured to automatically boost the primary battery when the primary battery fails to start the engine.

A cooler allows easy attachment and detachment of a battery. The cooler includes a main container including a refrigeration compartment, an evaporator on the main container, a compressor and a condenser adjacent to the main container, and at least one battery mount to receive a power tool battery in a detachable manner. The at least one battery mount is adjacent to the main container and above the compressor and the condenser.

A present heating system or heating and cooling system does not include a tank for storing potable hot water in anticipation of a potable hot water demand. Although one or more temperature sensors may be used for providing feedback to heating of the contents of a tank water heater to achieve a setpoint temperature, the effect of stratification can cause layers of fluid having different temperatures in the tank water heater. Therefore, although portions of the contents of a water heater may be disposed at a setpoint temperature that is unfavorable for Legionella proliferation, there potentially exists other portions that may be disposed at temperatures suitable for Legionella proliferation, especially when the contents have been left unused for an extended period of time.

A heating and cooling system powered by renewable energy and assisted with geothermal energy includes a solar cycling unit, a supercritical carbon dioxide (S—CO.sub.2) unit, and a refrigerant cycling unit. Solar energy obtained at the solar cycling unit may be used to power the S—CO.sub.2 cycling unit. To do so, the solar cycling unit utilizes a solar collector, a thermal energy storage, and a heat exchanger along with a first working fluid which is preferably molten salt or Therminol. Next, the energy generated at the S—CO.sub.2 cycling unit, which preferably circulates S—CO.sub.2 as a second working fluid, may be used to operate the refrigerant cycling unit. In the refrigerant cycling unit, Tetrafluroethene is preferably used as the third working fluid to produce required cooling effects. Additionally, geothermal heat exchangers may be integrated into the system for use during varying weather conditions.

Aspects of the present disclosure include a system for turbo-compression cooling. The system may be aboard a marine vessel. The system includes a power cycle and a cooling cycle. The power cycle includes a first working fluid, a waste heat boiler configured to evaporate the working fluid, a turbine, and a condenser. The condenser condenses the working fluid to a saturated or subcooled liquid. The cooling cycle includes a second working fluid, a first compressor configured to increase the pressure of the second working fluid, a condenser configured to condense the second working fluid to a saturated or subcooled liquid after exiting the first compressor, an expansion valve, and an evaporator. The turbine and first compressor are coupled one to the other. The waste heat boiler receives waste heat from engine jacket water and lubricating oil from a ship service generator. The evaporator cools water in a shipboard cooling loop.

A dynamic method of maintaining a predefined sub-cooling of a refrigerant exiting a condenser by dynamic control of the circulating mass of refrigerant, by transferring the refrigerant into or towards a receiver installed in parallel with the liquid connection between the condenser and the expansion valve, as a function of the difference in temperatures between the condensation temperature of the saturation liquid and the discharge temperature from the condenser.

In embodiments of a thermal and environmental control system an off-grid cold-storage facility has solar photovoltaic panels for producing electricity. A battery is in operable connection with the solar photovoltaic panels and configured to store the electricity produced by the solar photovoltaic panels. Cooling equipment is in operable connection to the battery and configured to regulate the temperature of the off-grid storage facility. Ventilation equipment is in operable connection to the battery to regulate air humidity and gas concentrations. A computer processor is provided at the off-grid storage facility and is in operable connection with the cooling equipment. The computer processor is configured to provide a regulating signal to the cooling equipment for optimizing battery usage, thermal setpoint, and environmental conditions. A cloud-based computing system is in operable communication to weather data and in operable communication to the computer processor. The cloud-based computing system is configured to compute optimized battery usage, thermal setpoint, and environmental conditions of the off-grid storage facility based on the weather data.

Techniques for operating a transport refrigeration system with an energy storage device include producing a first output and a second output at an energy storage device (ESD), and converting the first output and the second output to a converted first output and a converted second output. The techniques also include supplying the converted first output and the converted second output to components of the transport refrigeration system, and operating the components of the transport refrigeration system using the converted first output and the converted second output.

The present disclosure relates to a gas engine heat pump including: an engine which burns a mixed air of air and fuel; a first charger which compresses the mixed air and supplies to the engine; a first exhaust flow path which is connected to the engine, and through which exhaust gas discharged from the engine flows; and a second charger which is driven by the exhaust gas branched from the first exhaust flow path to a second exhaust flow path, and compresses the exhaust gas discharged from the engine and supplies the compressed exhaust gas to the engine, thereby reducing the emission of nitrogen oxide by recirculating the exhaust gas without additional power consumption.