RU73454U1 - HEAT FAN WITH HEAT VENT - Google Patents

Abstract

The utility model relates to electrical engineering, and more particularly to fan heaters used as heaters for industrial and domestic needs, and this design provides both a heating mode and a ventilation mode.

This utility model can be used in construction, light industry, agriculture and other sectors of the economy.

The essence of the utility model: a fan heater contains a metal or plastic case, an electric motor placed in it with an impeller on the shaft, the blades of which are resistive heating elements, and the heating elements are supplied with power using a current collector, the movable part of which is fixed to the motor shaft.

The technical result achieved by the utility model is an increase in the heat transfer coefficient, a decrease in the weight and size characteristics of the fan heater, an increase in the resource of the heating element. This result is achieved by changing the heat release along the length of the blade.

The utility model formula has 3 points.

Description

The utility model relates to electrical engineering, more specifically to thermal electric fans, used as heaters for industrial and domestic needs, for example: for space heating, drying, etc.

This utility model can be used in construction, light industry, agriculture and other sectors of the economy.

Fan heaters are known that have a heating element in the form of a tubular electric heater (TENA) and actually a fan that creates an air stream that moves relative to the heated surface of a fixed TENA (blows it) and removes the heat generated by the heating element. For example, patent RU 16305 U1 7 F24Н 3 \ 04 dated 12/20/2000.

In the specified fan heater, the technical result achieved by the proposed utility model is not provided, since the specified fan heater has lower heat transfer efficiency, large weight and size characteristics and a shorter resource.

A fan heater is also known having a heating element made in the form of thin-layer resistive loops (tracks) placed directly on the impeller blade. The heating elements and the impeller are a single unit. Patent RU 2072064 C1 6 F24H 3/04 dated 01/20/97. This fan heater was chosen by us for the prototype.

In the specified fan heater, the technical result achieved by the proposed utility model is not provided, since the specified fan heater has lower heat transfer efficiency.

The objective of the utility model is the creation of a fan heater with increased heat transfer efficiency, reduced weight and size characteristics and increased reliability.

The technical result achieved by the proposed utility model is to increase the heat transfer coefficient, reduce weight and size characteristics and increase reliability.

The technical result is achieved by the fact that a fan heater containing a metal or plastic case, an electric motor placed in it with an impeller on the shaft, on the blades of which are conductive material in the form of tracks that are resistive heating elements, the heating elements are supplied with power using a current collector, the movable part which is mounted on the motor shaft, and the heat dissipation of the resistive tracks increases in proportion to the distance from the axis of rotation of the cr stamens.

In special cases, this result is achieved by the fact that the heat dissipation of the blade is determined by the formula

_{Q r = Q o (r /} r o) k

where Q _r is the heat dissipation of the blade at a radius of g, W / m ² ;

Q _o - heat dissipation of the blade at a radius r _o from which the resistive layer begins, W / m ² ;

r is the current value of the radius, m;

r _o - radius of the beginning of the resistive layer, m;

k - exponent, varying in the range of 0.5 ÷ 1, as well as the ratio of the area of the resistive heating elements to the total area of the blade on which they are applied is determined by the following

the formula:

S _R / S _L ≥0,5,

where S _R is the area of the resistive heating elements;

S _l - the area of the blade.

Figure 1 schematically depicts the described fan heater with a thermal impeller. Figure 2 shows the site of the thermal impeller with applied heating elements.

The fan heater comprises a housing 1, an electric motor 2 located therein with an impeller 3 on a shaft, on the blades 4 of which a conductive material is applied in the form of tracks 5 representing resistive heating elements. The power of the heating elements is supplied using a current collector, the movable part of which 6 is fixed to the motor shaft, and the fixed part 7, including brushes 8, is fixed to the motor housing.

In the proposed design of the fan heater, the heat release of the heating element increases in the radial direction and thus the heat transfer efficiency also changes and reaches its maximum value on the periphery of the blade, this allows to increase the heat transfer of the impeller as a whole. The increase in heat transfer from the blade to the air allows you to remove more heat with the same power consumption of the heating elements, allows you to reduce the dimensions of the impeller, to prevent overheating of the impeller (resistive layer) near the axis of the impeller, which leads to an increase in resource.

The proposed fan heater works as follows.

From an alternating current network with a voltage of 220 / 380V, power is supplied to an electric motor, on the shaft of which there is a thermal impeller and a rotating current collector. Through the sliding contacts of the current collector, an alternating voltage of 220 V is supplied to the input of the impeller heating elements. The electric motor rotates the impeller blades, which are both heating elements and form a directed flow of warm air.

A prototype of a fan heater with a heat impeller has been developed, which is characterized by the following parameters: total power consumption of heating elements 3 kW, engine power 0.18 kW, rotation speed 1300 rpm, temperature of heating elements 500 ° C, air capacity in the outlet section 500 m ³ / h, ΔТ = 28 ° С, supply voltage ~ 220 V.

Tests of the fan heater were carried out, which confirmed the fulfillment of the task of the utility model and the achievement of the technical result.

Claims (3)

1. A fan heater containing a metal or plastic housing, an electric motor placed in it with an impeller on the shaft, on the blades of which are conductive material in the form of tracks, which are resistive heating elements, the heating elements are supplied with power using a current collector, the movable part of which is fixed to the shaft an electric motor, the heat dissipation of the resistive tracks increasing in proportion to the distance from the axis of rotation of the impeller. 2. The fan heater according to claim 1, characterized in that the heat dissipation of the blade is determined by the formula Q _r = Q _o (r / r _o ) ^k , where Q _r is the heat dissipation of the blade at a radius r, W / m ² ; Q _o - heat dissipation of the blade at a radius r _o , which begins the resistive layer, W / m ² ; r is the current value of the radius, m; r _o is the radius of the beginning of the resistive layer; k - exponent, varying in the range of 0.5 ÷ 1. 3. The fan heater according to claim 1 or 2, characterized in that the ratio of the area of the resistive heating elements to the total area of the blade on which they are applied is determined by the following formula: S _R / S _L ≥0.5, where S _R is the area of the resistive heating elements; S _l - the area of the blade.