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Thermal energy storage devices for cooling have become increasingly used in various areas of technology. Their operation is based on the use of preliminary cooling reserves built up by a heat-draining insert as a result of a first-order phase transition at low temperatures, such as evaporation, sublimation [1], or melting of the working medium [2].Since cooling reserves in the thermal energy storage device diminish as heat is withdrawn from the objects to be cooled, when needed for prolonged operation they are designed to allow for periodic charging. The charging method depends on the operating principle of the cryogenic thermal energy storage device. Repeated charging may be done using a refrigerator, a cryogenerator, or any other cooling device. For short-term operation, generally repeated charging of the thermal energy storage device is not required and thus its operating life is limited by the mount of cooling reserve.The operating life of the cooling thermal energy storage device, all other conditions being equal, is determined not only by the cooling reserve but also in many eases by the unacceptably large temperature difference developing over time as heat is transferred from the object to be cooled to the working medium. Such a limitation usually arises when cryostating ff and optoelectronic devices, in which the objects to be cooled cannot tolerate substantial changes in temperature.Accordingly, cryogenic thermal energy storage devices based on melting of solid cryogens have two major advantages: during heat input from the object to be cooled, the temperature of the melting working medium in the cryogenic thermal energy storage device remains constant; the change in the specific volume of the working medium during melting--freezing phase transitions is relatively small, which makes it possible to create cryogenic thermal energy storage devices without consumption of the working medium and accordingly allowing for periodic charging, i.e., cooling. Such devices are expediently used, for example, to increase the service life of gas-cycle cryogenic micromachines, and cryostating rf and optoelectronic devices which cannot tolerate exposure to noise, vibrations, electric or magnetic fields, etc.Under realistic conditions, withdrawal of heat from a heat-releasing object to a melting working medium occurs with some variable temperature difference between the object and the working medium. This is connected with the fact that a layer of liquid having significant thermal resistance is formed between the heat-releasing object and the melting cryogen. Since many heat-releasing objects do not tolerate a large variation in their temperature during the cooling process, we need to take special measures in designing cryogenic storage devices.In order to decrease the temperature difference between the heat-releasing object and the melting working medium, in the cryogenic thermal energy storage device we can place an insert made of material with high thermal conductivity, designed in the form of different types of fins or ...

The article considers the Combustion Turbine Inlet Cooling (CTIC) system — an experimental system for cooling the cycle air entering the gas microturbine unit. This enables to save electrical power of the unit generated at the design level in the period of seasonal increase in air temperature. Cooling of the air at the inlet to the turbocharger of the unit occurs up to its design temperature (which is, according to the ISO standard, equal to 15˚С). The basis of the CTIC model is an industrial cooling system based on a vapor compression refrigeration unit with a cold accumulator. Water ice is used as a cold storage medium in the accumulator, while ice water is used as a medium cooling the cycle air (ice water is water at a temperature of 0.5˚С – 1˚С). The eff ect of cooling of cycle air is achieved by pumping ice water coming from the cold accumulator through an air-to-water heat exchanger installed at the inlet to the turbocharger. The purpose of the study was to determine the operating time of a cold accumulator, depending on the speed of the circulating water. The experiments were carried out on a model of a cooling system with a cold accumulator having a 200 kg ice storage and working with the Capstone C-30 microturbine. Maintaining the temperature of the cycle air at its design level is achieved using a frequency-controlled circulation pump and a digital measurement and control system with the LabVIEW software package. The results of the study show that the considered CTIC system, while discharging the cold accumulator, is able to maintain the required design temperature of the cycle air at 15°C for 6 hours, which is quite enough to cover the peak load of the working day. Technical and economic parameters of the plant are evaluated.