Safety protection device of electrothermal film heater

Abstract

A safety protection device of electrothermal film heater comprises an electrothermal film plate, a bimetallic plate temperature controller mounted on the electrothermal film plate, wherein the bimetallic plate temperature controller is mounted at the upper part of the electrothermal film plate or at the water outlet of the electrothermal film heater. A bare bimetallic plate is directly covered on an insulated layer of the electrothermal film. A thermal actuator on the bimetallic plate cut off a power supply on the electrothermal film plate via the movements of opening and closing a connecting point in the bimetallic plate. The design combines the electronic circuit temperature controller with negative temperature coefficient thermister with the mechanical bimetallic kick temperature controller to form the temperature controller having at least two levels of safety protection, normally three levels, thereby making the safety protection device of the electrothermal film heater satisfy the national safety standard requirement, guaranteeing the safe and reliable use of the electrothermal film heater, laying foundations for electrothermal film heater in the household electrothermal heater, improving the electrothermal efficiency and laying foundations for saving energy.

Description

technical field [0001] The invention relates to a safety protection device for an electric heater, in particular to a heating protector for an electric heating film. Background technique [0002] Due to the fast heat conversion speed of the electric heating film, high heat energy conversion efficiency, and less thermal inertia, compared with the traditional electric heating tube, the heat conversion speed of the electric heating film is 20 times that of the electric heating tube, and the thermal efficiency can reach 98%. The use has significant benefits in saving energy and has become an ideal product to replace resistance wires or electric heating tubes. However, the electric heating film heaters sold on the market still have the following defects in terms of safety protection. They use negative temperature coefficient thermistors, That is, NTC performs safety protection. Since the thermistor temperature sensor with negative temperature coefficient needs to be equipped with...

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Problems solved by technology

[0002] Due to the fast heat conversion speed of the electric heating film, high heat energy conversion efficiency, and less thermal inertia, compared with the traditional electric heating tube, the heat conversion speed of the electric heating film is 20 times that of the electric heating tube, and the thermal efficiency can reach 98%. The use has significant benefits in saving energy and has become an ideal product to replace resistance wires or electric heating tubes. However, the electric heating film heaters sold on the market still have the following defects in terms of safety protection. They use negative temperature coefficient thermistors, That is, NTC performs safety protection. Since the thermistor temperature sensor with negative temperature coefficient needs to be equipped with complex electronic control circuits, CPU control circuits and programming software are indispensable. Because electronic circuits are prone to protection failures and electrical safety accidents, only a single The NTC system protection does not meet the requirements of national safety standards. National safety standards require that household electrical appliances must have double protection measures, so that in case one protection device fails, the second safety protection device exists to ensure the safety of users.

[0003] It is a conventional and effective safety protection device to use the sudden jump temperature controller to control the temperature of the electric heating tube heater. The memory type bimetal strip of the sudden jump thermostat sold on the market is completely enclosed by the metal shell because the bimetallic strip is completely closed. , its operating temperature is limited by the conduction speed of the metal shell, which greatly prolongs the response time of the bimetal sheet to temperature changes, and easily causes the overheating protection of the electric heating film to fail. Therefore, according to the requirements of national safety standards, the thermistor with a negative temperature coefficient must On the basis of the protection system, an improved sudden jump temperature controller is added to meet the standard requirements of double safety protection for electric heating film heaters

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