Refrigerated merchandiser with modular evaporator coils and EEPR control

Abstract

An air cooling and control system for a refrigerated food merchandiser having an insulated cabinet with a product area having adjacent product zones, plural modular evaporator coil sections of substantially equal heat exchange potential and being of predetermined length and arranged in horizontal, spaced, end-to-end predetermined disposition and separate air moving means associated with each coil section and a corresponding product zone for circulating separate air flows through the coil sections and to the product area for cooling. The system further includes a first refrigerant metering valve for controlling liquid refrigerant flow on the high side of the evaporator sections, and a second refrigerant metering valve for controlling suction pressure and refrigerant vapor flow on the low side of the evaporator sections. An electronic control senses exit air temperatures downstream of the evaporator sections and operates the second metering valve in response thereto. In another aspect, a method of operating an electronic evaporator pressure regulating (EEPR) valve during the refrigeration and defrost modes of the controlled evaporator and in response to sensed air temperature<DEL-S DATE="20020409" ID="DEL-S-00001" / >s<DEL-E ID="DEL-S-00001" / > .

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates generally to the commercial refrigeration art, and more particularly to improvements in food product merchandisers and temperature control systems therefor.2. Description of Prior ArtGreat advances have been made in the last forth years in the field of commercial food merchandising with the improved insulation materials, better refrigerants, more efficient air handlers and condensing unit systems, better lighting and the universal use of ambient air temperature and humidity control in food stores and the like. A long checklist of important factors influence the construction and manufacture of food merchandisers including refrigeration requirements and performance, structural engineering for strength, durability and safety as well as insulation effect, servicing capability, product merchandising potential, and both manufacturing and operating costs.In today's marketplace a wide variety of food merchandisers ar...

AI Technical Summary

Benefits of technology

It is a principal object of the present invention to provide a novel modular evaporator coil that facilitates modular design and fabrication of different refrigerated fixtures, that provides increased coil capacity with a smaller coil size having a reduced refrigerant charge and improved efficiency; that produces better product temperatures; that eliminates return bends and evaporator coil joints and minimizes refrigerant leaks; that can be used in multiple, parallel-piped sections with one or more liquid metering controls; that is responsive to both liquid and suction controls; and that accommodates ease of manufacture, installation and service. Another feature of the invention is in controlling the operation of commercial refrigerator evaporators to maintain preselected food zone temperatures at substantially constant values. Another object is to provide an EEPR valve for suction control of the associated evaporator means during refrigeration and defrost modes and in response to sensed and projected exit air temperatures. Still another object is to provide an improved apparatus and control strategy for regulating the suction pressure of refrigeration evaporators to achieve operating temperatures and maintain exit air and display zone temperatures. These and still other objects and advantages will become more apparent hereinafter.

Problems solved by technology

Furthermore, although such a location does not interfere with the structural soundness of a coffin-type merchandiser, it has been discovered that a back wall evaporator coil location limits the structural support capability for internal vertical frames in multi-deck merchandisers, and the cantilever suspension of glass front panels in a deli merchandiser.

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