Plate Surfaces Of Evaporators

Another method of construction used for manufacturing of plates-surface evaporators takes tube is formed bare-tube evaporator and sandwiches between two conductive plates. The edges of these plates welded together, as shown in the to increase the heat transfer surface bare-tube evaporator. The space between the plates evacuated, allowing the pressure of the atmosphere to push the plate tightly clutching the receiver. This strategy will increase the contact between the pipe and plate, providing a good thermal contact between the secondary surface of the plates and tubes, carrying refrigerant. Evacuation of the space also removes the air, reducing the heat transfer resistance between die secondary and primary surface. In some designs, sparse space is filled with coolant.

This evaporator type are usually used in transport refrigeration trailers to maintain the temperature of storage of food products in the distribution process. In these applications cooled brine is used as a secondary refrigerant, which flows through the tube plate, where the truck was parked on warehouse terminals. Flexible hoses delivery refrigerant disconnected from the evaporator when the truck is ready to leave the terminal. Vacuum plate evaporator is no reserve of thermal power, when the refrigerant flow stops, related effect of cooling heat exchangers also stops. Thermal mass die product is used to maintain the temperature of the die trailer within a reasonable range, while the food is distributed.

To reduce the rate of temperature increase in the trailer, the space between the plates evacuated plate evaporator can be filled with a solution that can undergo a phase transition in the desired trailer temperature. Liquid adds thermal mass of the coil, which slows the rate of temperature change that occurs in the trailer. Phase transition of the die fluid allows the refrigeration effect continues after the trailer is disconnected from the refrigerant lines on the terminal. The void between evacuated plate is filled with widi is the eutectic solution. EU-tectic solution is a mixture of substances, which has a lower melting point possible for any combination of the same components. Water and salt mixtures are used as the eutectic solution in most cooling processes. As eutectic solution to the plate evaporator changes its state from solid to liquid, it continues to absorb heat energy from the refrigerated space. This response is similar to the action of an ice floe in the early household refrigerator.

Eutectic-solution-filled evaporators used in refrigerated transportation applications are installed on the ceiling and walls of the truck. They are connected to a Central refrigeration plant system, while die trucks parked die tenninal night. During this period of coolant from the Central railway station refrigerator cools die product in the truck, and also allows the eutectic solution to change its state to the solid. When the truck was preparing to leave the terminal, die refrigerant lines are off, interrupting the flow of refrigerant in the trailer.

Refrigeration capacity is stored in the latent heat of eutectic solution, as a rule, sufficient to maintain the required temperature of the product throughout the day. Temperature plates depends on a mixture of ingredients used in the development of the eutectic solution. Each approach has different fusion temperature, ranging from 67 27F (-55 to-2.8C).

Plate evaporators may be designed to operate as individual units or piped together in the evaporator banks. Hosting multiple blocks in the Bank increases the heat exchange capacity of the system. In these designs, the direct and reverse collectors are used for connection of a parallelepiped plate in one Bank, as shown in Fig. 14-6. The plates can also be placed in series configuration refrigerant flow. Plate surfaces of evaporators can be developed as a product shelf in the freezer rooms and other facilities of storage. They are also widely used as partitions in freezers, frozen food display cases, ice cream cabinets, sparkling water and similar applications.

Plate evaporators engaged in air-conditioning applications, including liquid cooling and maximum load meet periodically. In these strategies, one or more cylindrical containers of water are stored on site. Each containment vessel plate evaporators, suspended in water. In periods of low load and less expensive electricity, plate evaporators extract heat from the water, turning it into the icy slush. When the heat load of the system increases beyond the capacity chiller evaporator heat transfer ice, forges water, air-condition buildings. In these conditions, mechanical system running at maximum power during the melting of the ice provides additional peak load requirements of the process. The thermal capacity of the ice storage reduces the maximum capacity of refrigerating equipment at an amount equal to the cooling effect of ice. This strategy reduces the initial cost of equipment and installation together with the annual operating costs of the project...