Direct-current power supply electric floor heating system

Abstract

The utility model discloses an electric floor heating system powered by direct current, and belongs to the field of electric floor heating. An electric floor heating system powered by direct current comprises an electric heating film, a full-bridge rectifying circuit, an energy storage capacitor unit, a time relay, an alternating current contactor and a power resistor. According to the electric floor heating system powered by the direct current, the mains supply is converted into the direct current, then the electric heating film is powered, and due to the fact that the direct current power supply has no frequency, an alternating electric field and an alternating magnetic field are not generated, electric field intensity is not generated, and the electric field intensity is zero. The problem of high electric field intensity of an electrothermal film without a shielding layer can be effectively solved.

Description

Technical Field

[0001] This utility model belongs to the field of electric floor heating, and in particular relates to a DC-powered electric floor heating system. Background Technology

[0002] Electric underfloor heating involves embedding a heating film or heating cable with an external operating temperature limit of 70°C into the floor. The heating film or heating cable serves as the heat source to heat the floor or tiles, and a thermostat controls the room or floor temperature to achieve radiant floor heating. It has advantages such as comfort, energy saving, environmental protection, flexibility, and no maintenance. The heating film, with its surface heating, provides uniform heating and lower temperature for the same power, making it the mainstream choice.

[0003] Electric underfloor heating systems using heating films as a heat source typically employ multiple sheets of heating film, covering 60-70% of the room area. There is a certain distance between the heating films, and for ease of cutting, the heating elements within the films are also spaced apart. When using alternating current, an electric field intensity exceeding 1000V / m will exist at the edges of each unshielded heating element and along the conductors. Although studies have shown that power frequency electric field intensity has no impact on human health, and it decreases cubically with increasing distance (becoming undetectable at 30cm from the heating element), the fact that electric underfloor heating is laid underground with the heating film only 1-5cm above the ground means that the distance between the feet and the heating film is relatively small during use, which may cause slight discomfort for people sensitive to electric field intensity. The alternating electric field generates an alternating magnetic field, which in turn generates an alternating electric field. If electronic products are placed too close to the heating film, it can also have a certain impact on precision electronic instruments and equipment. However, the use of shielding layers in electric heating films can lead to breakdowns between the shielding layer and the live wire in the event of damage or defects, due to the relatively thin PET film. In addition, the use of shielding layers increases costs. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a DC-powered electric floor heating system that converts mains power into DC power and then supplies power to the heating film, which can effectively solve the problem of high electric field strength of the heating film without a shielding layer.

[0005] This utility model is achieved through the following technical solution: a DC-powered electric floor heating system, comprising an electric heating film, a full-bridge rectifier circuit, an energy storage capacitor unit, a time relay, an AC contactor, and a power resistor; the AC terminal of the full-bridge rectifier circuit is connected to an AC power supply, and the negative terminal of the DC terminal of the full-bridge rectifier circuit is connected to the negative terminal of the energy storage capacitor unit; the positive terminal of the DC terminal of the full-bridge rectifier circuit is connected to one end of the power resistor, and the other end of the power resistor is connected to the positive terminal of the energy storage capacitor unit; the positive terminal of the DC terminal of the full-bridge rectifier circuit is connected to the input terminal of the first main contact of the AC contactor, and the output terminal of the first main contact of the AC contactor... The time relay is connected to the positive terminal of the energy storage capacitor unit; the power supply terminal of the time relay is connected to the AC power supply; one end of the normally open pin of the time relay is connected to one coil contact of the AC contactor; the other end of the normally open pin of the time relay is connected to the live wire of the AC voltage; the other coil contact of the AC contactor is connected to the neutral wire of the AC power supply; the input terminal of the second main contact of the AC contactor is connected to the positive terminal of the energy storage capacitor unit; the input terminal of the third main contact of the AC contactor is connected to the negative terminal of the energy storage capacitor unit; and the output terminals of the second and third main contacts of the AC contactor are connected to the power input terminal of the heating film.

[0006] Furthermore, the electric floor heating system also includes a bleed resistor, one end of which is connected to the positive terminal of the energy storage capacitor unit, and the other end of which is connected to the negative terminal of the energy storage capacitor unit.

[0007] Furthermore, the discharge resistor has a specification of 100kΩ.

[0008] Furthermore, the heating film is a PTC heating film.

[0009] Furthermore, the PTC strength of the PTC electrothermal film is greater than or equal to three.

[0010] Furthermore, the energy storage capacitor unit includes multiple capacitors connected in parallel.

[0011] Furthermore, the energy storage capacitor unit includes six capacitors connected in parallel.

[0012] Furthermore, the capacitor is specified as 450V, 1000uf.

[0013] Furthermore, the power resistor is specified as 200Ω, 20W.

[0014] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0015] (1) This utility model provides a DC-powered electric floor heating system that converts mains power into DC power and then supplies power to the electric heating film. Since DC power has no frequency, it does not generate an alternating electric field or an alternating magnetic field, and therefore does not generate an electric field strength. The electric field strength is zero, which can effectively solve the problem of high electric field strength of the electric heating film without a shielding layer.

[0016] (2) Direct current (DC) has no alternating losses (such as the skin effect) during transmission, resulting in higher conductor utilization. For heating cables or heating films in electric underfloor heating, DC may reduce line losses and improve the efficiency of converting electrical energy into heat energy. Experiments show that DC is more stable than AC in certain scenarios, which may reduce the frequent start-stop of the thermostat caused by voltage fluctuations, thereby extending the equipment life;

[0017] (3) AC equipment may generate low-frequency electromagnetic fields. Although existing studies have shown that the electromagnetic radiation of electric floor heating is harmless to the human body, DC power systems can further reduce electromagnetic interference, and are especially suitable for electromagnetically sensitive environments (such as medical or precision laboratories).

[0018] (4) The risk of electric shock from direct current is lower than that from alternating current. Alternating current may cause muscle spasms, while direct current is less harmful to the human body at the same voltage, and is especially suitable for places with higher safety requirements (such as children's rooms or bathrooms).

[0019] (5) Converting AC power to DC power can double the power without changing the heating film. If the power remains unchanged, the current can be reduced to 70% of the original. As the current carrying capacity of the heating film circuit decreases, the safety of the heating film circuit can be improved. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the principle of the electric underfloor heating system of this utility model. Detailed Implementation

[0022] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0025] In the description of this utility model, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating the connection relationship between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] like Figure 1 As shown, this utility model discloses a DC-powered electric floor heating system.

[0027] This embodiment discloses a DC-powered electric floor heating system, such as... Figure 1 As shown, the electric floor heating system includes an electric heating film, a full-bridge rectifier circuit, an energy storage capacitor unit, a time relay KT, an AC contactor KM, and a power resistor R1.

[0028] The AC terminal of the full-bridge rectifier circuit is connected to an AC power supply. The negative terminal of the DC terminal of the full-bridge rectifier circuit is connected to the negative terminal of the energy storage capacitor unit. The positive terminal of the DC terminal of the full-bridge rectifier circuit is connected to one end of the power resistor R1. The positive terminal of the DC terminal of the full-bridge rectifier circuit is connected to the input terminal of the first main contact of the AC contactor KM. The output terminal of the first main contact of the AC contactor KM is connected to the positive terminal of the energy storage capacitor unit. The output terminal of the first main contact of the AC contactor KM is the output terminal corresponding to the input terminal of its first main contact.

[0029] For example, the full-bridge rectifier circuit includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The cathode of the first diode D1 is connected to the cathode of the second diode D2 to form the positive DC terminal of the full-bridge rectifier circuit. The anode of the first diode D1 is connected to the cathode of the fourth diode D4 to form one AC terminal of the full-bridge rectifier circuit. The anode of the second diode D2 is connected to the cathode of the third diode D3 to form the other AC terminal of the full-bridge rectifier circuit. The anode of the third diode D3 is connected to the anode of the fourth diode D4 to form the negative DC terminal of the full-bridge rectifier circuit.

[0030] The other end of the power resistor R1 is connected to the positive terminal of the energy storage capacitor unit. The power resistor R1 is used to charge the capacitor with the initial AC power supply, and at the same time, it limits the current to prevent the capacitor from having an excessive current at the moment the power is turned on, which could damage the switch contacts.

[0031] For example, the power resistor R1 is specified as 200Ω, 20W.

[0032] The power supply terminal of the time relay KT is connected to an AC power supply. One end of the normally open pin of the time relay KT is connected to a coil contact of the AC contactor KM, and the other end of the normally open pin of the time relay KT is connected to the live wire of the AC voltage. The other coil contact of the AC contactor KM is connected to the neutral wire of the AC power supply.

[0033] The time relay KT sets the delay time according to the capacitance of the energy storage capacitor unit and the power resistor R1, t=R*C. When the voltage of the capacitor approaches the saturation voltage, the coil of the AC contactor KM is connected, which drives the normally open contact to close, thereby supplying power to the heating film.

[0034] The second main contact input terminal of the AC contactor KM is connected to the positive terminal of the energy storage capacitor unit, the third main contact input terminal of the AC contactor KM is connected to the negative terminal of the energy storage capacitor unit, and the second and third main contact output terminals of the AC contactor KM are connected to the power input terminal of the heating film. The second main contact output terminal of the AC contactor KM is the output terminal corresponding to its second main contact input terminal, and the third main contact output terminal of the AC contactor KM is the output terminal corresponding to its third main contact input terminal.

[0035] In some embodiments of this example, the electric floor heating system further includes a bleed resistor R2, one end of which is connected to the positive terminal of the energy storage capacitor unit, and the other end of which is connected to the negative terminal of the energy storage capacitor unit.

[0036] For example, the discharge resistor R2 has a specification of 100kΩ.

[0037] In these embodiments, a discharge resistor R2 is connected to the positive and negative terminals of the energy storage capacitor unit to dissipate the voltage on the capacitor when the power is turned off, thus preventing electric shock.

[0038] In some embodiments of this example, the heating film is a PTC heating film. For example, the PTC intensity of the PTC heating film is greater than or equal to three.

[0039] In some embodiments of this example, the energy storage capacitor unit includes multiple capacitors connected in parallel. For example, the energy storage capacitor unit includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6, which are connected in parallel. The specifications of the first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, fifth capacitor C5, and sixth capacitor C6 are 450V and 1000uF.

[0040] In this embodiment, the AC220V or AC380V power supply is converted to DC311V or DC537V DC power supply to power the heating film. The internal electrodes of the heating film are composed of comb-shaped electrodes, and the positive and negative electrodes are connected through a conductive ink layer to form a conductive path. Since the DC power supply has no frequency, it does not generate an alternating electric field or an alternating magnetic field, and therefore does not generate an electric field strength, which is zero.

[0041] In one case, the electric underfloor heating system described in this example was installed and tested in a 22-square-meter room. The electromagnetic radiation monitoring instrument showed that the electric and magnetic field strengths on the underfloor heating surface were both zero, consistent with the theoretical values.

[0042] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A DC-powered electric underfloor heating system, characterized in that, This system includes an electric heating film, a full-bridge rectifier circuit, an energy storage capacitor unit, a time relay, an AC contactor, and a power resistor. The AC terminal of the full-bridge rectifier circuit is connected to an AC power supply, and the negative terminal of the DC terminal of the full-bridge rectifier circuit is connected to the negative terminal of the energy storage capacitor unit. The positive terminal of the DC terminal of the full-bridge rectifier circuit is connected to one end of the power resistor, and the other end of the power resistor is connected to the positive terminal of the energy storage capacitor unit. The positive terminal of the DC terminal of the full-bridge rectifier circuit is connected to the input terminal of the first main contact of the AC contactor, and the output terminal of the first main contact of the AC contactor is connected to the positive terminal of the energy storage capacitor unit. The time relay... The power supply terminal of the relay is connected to the AC power supply. One end of the normally open pin of the time relay is connected to one coil contact of the AC contactor, and the other end of the normally open pin of the time relay is connected to the live wire of the AC voltage. The other coil contact of the AC contactor is connected to the neutral wire of the AC power supply. The input terminal of the second main contact of the AC contactor is connected to the positive terminal of the energy storage capacitor unit, and the input terminal of the third main contact of the AC contactor is connected to the negative terminal of the energy storage capacitor unit. The output terminals of the second and third main contacts of the AC contactor are connected to the power input terminal of the heating film.

2. The DC-powered electric underfloor heating system according to claim 1, characterized in that, The electric floor heating system also includes a bleed resistor, one end of which is connected to the positive terminal of the energy storage capacitor unit, and the other end of which is connected to the negative terminal of the energy storage capacitor unit.

3. The DC-powered electric floor heating system according to claim 2, characterized in that, The bleeder resistor is rated at 100kΩ.

4. The DC-powered electric underfloor heating system according to claim 1, characterized in that, The heating film is a PTC heating film.

5. A DC-powered electric underfloor heating system according to claim 4, characterized in that, The PTC strength of the PTC electrothermal film is greater than or equal to three.

6. The DC-powered electric underfloor heating system according to claim 1, characterized in that, The energy storage capacitor unit includes multiple capacitors connected in parallel.

7. A DC-powered electric underfloor heating system according to claim 1, characterized in that, The energy storage capacitor unit comprises six capacitors connected in parallel.

8. A DC-powered electric underfloor heating system according to claim 6 or 7, characterized in that, The capacitor is rated for 450V and 1000uf.

9. A DC-powered electric underfloor heating system according to claim 1, characterized in that, The power resistor is specified as 200Ω, 20W.

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