Temperature Control in Thermal Batteries (Termostatirovanie Teplovykh Batarei)

Abstract : Temperature control in thermal batteries, whose operation depends on the melting of an electrolyte by means of pyrotechnic heating, is provided in order to maintain the temperature of the electrochemical elements (EKhE) within the required working range of 350-700 C. Existing methods of temperature control in thermal batteries are classified as active and passive. Passive temperature control provides thermal stability of the EKhE mass by placing around it layers of thermal insulating material. Active temperature control provides for the introduction of heat into the element block from one or another source arranged inside the battery, and for it to be effective over the working period. Thermal insulating layers are commonly achieved by means of materials of low heat conduction which must exhibit chemical stability against molten salts, withstand short-term temperature rise, and be mechanically stable against shock and centrifugal loads. In thermal batteries tough, resilient thermal insulators are employed. Kaolin-based fabric, fibreglass and asbestos are used in such materials. The element block may be wrapped in them; it is also possible to have alternate layers of various materials, for example, ceramic, glass fibre or mica.