VARIABLE-FREQUENCY HEATER

Abstract

A variable-frequency heater, which is provided in a heating space. A plurality of hot air channels are embedded in walls of the heating space. Hot air is output from the variable-frequency heater to the hot air channels for heating the heating space. The variable-frequency heater includes a housing, which includes a first enclosure plate, a second enclosure plate, a front support plate and an access panel, and a temperature controller. The housing is internally provided with a gas heating assembly, which includes a heat exchanger at a front end inside the housing. The heat exchanger is provided with an igniter. The access panel is provided with an exhaust panel, which is provided with an air outlet pipe and an air inlet pipe connected to the heat exchanger. The first enclosure plate is provided with a gas pipe connected to a gas source.

Claims

1. A variable-frequency heater, the variable-frequency heater being provided in a heating space, a plurality of hot air channels being embedded in walls of the heating space, the variable-frequency heater being configured to output hot air to the plurality of hot air channels for heating the heating space, and the variable-frequency heater comprising: a housing; and a temperature controller; wherein the housing comprises a first enclosure plate, a second enclosure plate, a front support plate and an access panel; the housing is internally provided with a gas heating assembly; the gas heating assembly comprises a heat exchanger mounted at a front end inside the housing; and the heat exchanger is provided with an igniter; the access panel is provided with an exhaust panel; the exhaust panel is provided with an air outlet pipe and an air inlet pipe that are connected to the heat exchanger; the air inlet pipe is connected to a fan such that air is blown into the heat exchanger to assist combustion; and the air outlet pipe is connected to an exhaust port of the heat exchanger; and the first enclosure plate is provided with a gas pipe connected to a gas source; the gas pipe is connected to an inlet end of a gas proportional valve; and an outlet end of the gas proportional valve is connected to the igniter through a pipeline.

2. The variable-frequency heater of claim 1, wherein the heat exchanger comprises a first structural part and a second structural part connected to each other; and the first structural part and the second structural part are both C-shaped; the first structural part is provided with a first groove, and the second structural part is provided with a second groove; and the first groove and the second groove are arranged opposite to each other, and are configured to form a dual-layer flow channel; and an upper end and a lower end inside the second structural part are each provided with a connector; and two connectors are connected with each other, and are connected to the second groove.

3. The variable-frequency heater of claim 1, wherein the igniter comprises a base plate mounted at a mouth of the heat exchanger; the base plate is provided with a nozzle fixing hole; a primary air distribution hole is provided on an outer side of the nozzle fixing hole; a side of the base plate is connected to a connecting pipe; the connecting pipe is connected to a burner; and the connecting pipe is provided at the primary air distribution hole; the burner is provided with a bracket; the bracket is provided with a lead-out electrode; the bracket is provided with an ignition pin above the lead-out electrode; a rear end of the ignition pin is connected to a feedback electrode with a pointed structure; mounting positions of the feedback electrode, the ignition pin and the lead-out electrode on the bracket are each provided with an insulating pad; and the base plate is further provided with a secondary air distribution hole and a plurality of mounting holes; and the secondary air distribution hole is arranged at an outer side of the primary air distribution hole.

4. The variable-frequency heater of claim 1, wherein the fan comprises a fixing plate; the fixing plate is provided with a motor; and a first side of the motor is provided with a first impeller housing, and a second side of the motor is provided with a second impeller housing; the first impeller housing is rotatably provided with a heating impeller; a combustion impeller is rotatably mounted in the second impeller housing; and the combustion impeller and the heating impeller are connected to a rotating shaft of the motor; a front side of the second impeller housing is connected to an air inlet, and a rear side of the second impeller housing is provided with an air outlet connected to the heat exchanger; a side of the air inlet is provided with a first sampling port; the air outlet of the second impeller housing is provided with a second sampling port; and an air pressure sensor is provided inside the housing, wherein the air pressure sensor is an air differential pressure sensor; the first sampling port is connected to a negative pressure detection terminal of the air pressure sensor, and the second sampling port is connected to a positive pressure detection terminal of the air pressure sensor; and an air output direction of the heating impeller is configured to be oriented rearwardly, and face toward the heat exchanger; and an air outlet of the heating impeller is provided with a flow guide plate.

5. The variable-frequency heater of claim 1, wherein a temperature control switch is provided inside the housing at a side of the heat exchanger, and a controller is provided inside the housing at a side of the fan.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] FIG. 1 structurally shows a rear portion of a variable-frequency heater according to an embodiment of the present disclosure;

[0033] FIG. 2 structurally shows a front portion of the variable-frequency heater according to an embodiment of the present disclosure;

[0034] FIG. 3 is an exploded view of the variable-frequency heater according to an embodiment of the present disclosure;

[0035] FIG. 4 schematically shows an operation principle of the variable-frequency heater according to an embodiment of the present disclosure;

[0036] FIG. 5 is an external structural diagram of an igniter according to an embodiment of the present disclosure;

[0037] FIG. 6 is a side view of the igniter according to an embodiment of the present disclosure;

[0038] FIG. 7 is a rear view of a fan according to an embodiment of the present disclosure;

[0039] FIG. 8 is a side view of the fan according to an embodiment of the present disclosure;

[0040] FIG. 9 is an internal structural diagram of the fan according to an embodiment of the present disclosure;

[0041] FIG. 10 is an external structural diagram of a heat exchanger according to an embodiment of the present disclosure;

[0042] FIG. 11 is a rear view of the heat exchanger according to an embodiment of the present disclosure;

[0043] FIG. 12 is a structural diagram of a second structural part according to an embodiment of the present disclosure;

[0044] FIG. 13 is a structural diagram of a first structural part according to an embodiment of the present disclosure; and

[0045] FIG. 14 schematically shows a connection between the first structural part and the second structural part according to an embodiment of the present disclosure.

[0046] In the figures: 1first enclosure plate; 2second enclosure plate; 3front support plate; 4access panel; 5heat exchanger; 5-1first structural part; 5-2second structural part; 5-3groove; 5-4connector; 6igniter; 6-1base plate; 6-11nozzle fixing hole; 6-12primary air distribution hole; 6-13secondary air distribution hole; 6-14mounting hole; 6-2connecting pipe; 6-3burner; 6-4bracket; 6-5ignition pin; 6-6feedback electrode; 6-7lead-out electrode; 7fan; 7-1fixing plate; 7-2motor; 7-3heating impeller; 7-4first impeller housing; 7-5combustion impeller; 7-6second impeller housing; 7-7air inlet; 7-8second sampling port; 7-9first sampling port; 8flow guide plate; 9controller; 10gas pipe; 11gas proportional valve; 12exhaust panel; 13air inlet pipe; 14air outlet pipe; 15air pressure sensor; 16temperature control switch; 17hot air channel; 18heating space; and 19temperature controller.

DETAILED DESCRIPTION OF EMBODIMENTS

[0047] The present disclosure will be further clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, described herein are merely some embodiments of the present disclosure, rather than all embodiments. Based on the embodiments provided herein, all other embodiments obtained by those of ordinary skill in the art without making creative effort shall fall within the scope of the present disclosure.

[0048] An embodiment of the present disclosure provides a variable-frequency heater. Referring to FIGS. 1-3, the variable-frequency heater is provided in a heating space 18. A plurality of hot air channels 17 are embedded in walls of the heating space 18. The variable-frequency heater is configured to output hot air output to the hot air channels 17 for heating the heating space 18. The variable-frequency heater includes a housing and a temperature controller 19. The temperature controller 19 is a remote controller or a wired control panel. The housing includes a first enclosure plate 1, a second enclosure plate 2, a front support plate 3 and an access panel 4. The housing is internally provided with a gas heating assembly. The gas heating assembly includes a heat exchanger 5 mounted at a front end inside the housing. The heat exchanger 5 is provided with an igniter 6. The access panel 4 is provided with an exhaust panel 12. The exhaust panel 12 is provided with an air outlet pipe 14 and an air inlet pipe 13 that are connected to the heat exchanger 5. The air inlet pipe 13 is connected to a fan 7 such that air is blown into the heat exchanger 5 to assist combustion. The air outlet pipe 14 is connected to an exhaust port of the heat exchanger 5. The first enclosure plate 1 is provided with a gas pipe 10 connected to a gas source. The gas pipe 10 is connected to an inlet end of a gas proportional valve 11. An outlet end of the gas proportional valve 11 is connected the igniter 6 through a pipeline. A temperature control switch 16 is provided inside the housing at a side of the heat exchanger 5. A controller 9 is provided inside the housing at a side of the fan 7.

[0049] Referring to FIGS. 1-14, the heat exchanger 5 includes a first structural part 5-1 and a second structural part 5-2 connected to each other. The first structural part 5-1 and the second structural part 5-2 are both C-shaped and integrally formed. The first structural part 5-1 is provided with a first groove 5-3. The second structural part 5-2 is provided with a second groove 5-3. The first groove 5-3 and the second groove 5-3 are arranged opposite to each other, and are configured to form a dual-layer flow channel. An upper end and a lower end inside the second structural part 5-2 are each provided with a connector 5-4. Two connectors 5-4 are connected with each other, and are connected to the second groove 5-3.

[0050] The first structural part 5-1 and the second structural part 5-2 are formed of sheet-metal components, which enables simple and efficient manufacturing and provides uniform material distribution. Compared with conventional die-casting technology, the sheet-metal components have a reduced material thickness, resulting in higher heat exchange efficiency, faster heat transfer, improved durability and lower production cost. The use of a dual-layer flow channel allows to naturally generate a temperature gradient during the heat exchange process, enhance airflow, and extend the heat exchange path of the flue gas, thereby achieving higher thermal utilization. During operation, the combustion gas is separated from the external air, and the exhaust gas is forcibly discharged, thereby preventing poisoning.

[0051] Referring to FIGS. 1-6, the igniter 6 includes a base plate 6-1 mounted at a mouth of the heat exchanger 5. The base plate 6-1 is provided with a nozzle fixing hole 6-11. A primary air distribution hole 6-12 is provided on an outer side of the nozzle fixing hole 6-11. A side of the base plate 6-1 is connected to a connecting pipe 6-2. The connecting pipe 6-2 is connected to a burner 6-3. The connecting pipe 6-2 is provided at the primary air distribution hole 6-12. The burner 6-3 is provided with a bracket 6-4. The bracket 6-4 is provided with a lead-out electrode 6-7. The bracket 6-4 is provided with an ignition pin 6-5 above the lead-out electrode 6-7. A rear end of the ignition pin 6-5 is connected to a feedback electrode 6-6 with a pointed structure. Mounting positions of the feedback electrode 6-6, the ignition pin 6-5 and the lead-out electrode 6-7 on the bracket 6-4 are each provided with an insulating pad. The base plate 6-1 is further provided with a secondary air distribution hole 6-13 and a plurality of mounting holes. The secondary air distribution hole is arranged at an outer side of the primary air distribution hole 6-12.

[0052] During ignition, the ignition pin 6-5 emits high-voltage electricity to produce an electric arc between the ignition pin 6-5 and the lead-out electrode 6-7 that is closest to the ignition pin 6-5, thereby igniting the mixture of combustible gas and oxygen. At the same time, the feedback electrode 6-6 and the ignition pin 6-5 respectively detect the flame from opposite ends. Once the flame is detected by either the ignition pin 6-5 or the feedback electrode 6-6, a feedback signal can be generated. After the fan 7 is started, an airflow is introduced respectively through the primary air distribution hole 6-12 and the secondary air distribution hole 6-13. The airflow entering through the primary air distribution hole 6-12 is delivered into the burner 6-3 to mix with the combustible gas for combustion, while the airflow entering through the secondary air distribution hole 6-13 is divided into two parts: one part participates in combustion by contacting the flame on an outer side of the burner 6-3, thereby improving combustion efficiency, and the other part guides the flame from the outside and wraps around the flame, thereby controlling the temperature of the heat exchanger 5.

[0053] Referring to FIGS. 1-9, the fan 7 includes a fixing plate 7-1. The fixing plate 7-1 is provided with a motor 7-2. A first side of the motor 7-2 is provided with a first impeller housing 7-4, a second side of the motor 7-2 is provided with and a second impeller housing 7-6. The first impeller housing 7-4 is rotatably provided with a heating impeller 7-3. A combustion impeller 7-5 is rotatably mounted in the second impeller housing 7-6. The combustion impeller 7-5 and the heating impeller 7-3 are connected to a rotating shaft of the motor 7-2. A front side of the second impeller housing 7-6 is connected to an air inlet 7-7, and a rear side of the second impeller housing 7-6 is provided with an air outlet connected to the heat exchanger 5. A side of the air inlet 7-7 is provided with a first sampling port 7-9. The air outlet of the second impeller housing 7-6 is provided with a second sampling port 7-8. An air pressure sensor 15 is provided inside the housing. The air pressure sensor 15 is an air differential pressure sensor. The first sampling port 7-9 is connected to a negative pressure detection terminal of the air pressure sensor 15. The second sampling port 7-8 is connected to a positive pressure detection terminal of the air pressure sensor 15. An air output direction of the heating impeller 7-3 is configured to be oriented rearwardly, and face toward the heat exchanger 5. An air outlet of the heating impeller 7-3 is provided with a flow guide plate 8.

[0054] The motor 7-2 can simultaneously drive the combustion impeller 7-5 and the heating impeller 7-3 to operate, thereby respectively performing combustion and heat dissipation functions. The air pressure sensor 15 is configured to continuously acquire pressure values from the first sampling port 7-9 and the second sampling port 7-8, and calculates a pressure difference between the acquired pressure values. When the motor 7-2 is not in operation, the pressure value acquired at the second sampling port 7-8 is zero. After the fan 7 is started, the pressure value acquired at the second sampling port 7-8 changes, indicating that the variable-frequency heater is operating normally. When the air inlet 7-7 is blocked, the first sampling port 7-9 is subjected to turbulence and suction caused by the fan 7, resulting in a significant increase in negative pressure, while the second sampling port 7-8 experiences a decrease in positive pressure as no air is drawn from the air inlet 7-7. As a result, the overall pressure difference rapidly increases, an output signal of the air pressure sensor 15 changes rapidly, and a mainboard of the variable-frequency heater can read the data to perform shutdown protection. When the exhaust port is blocked, the second sampling port 7-8 is subjected to forced airflow delivered by the fan 7, resulting in a significant increase in positive pressure, while the first sampling port 7-9 experiences a reduction in negative pressure. Accordingly, the pressure difference monitored by the air pressure sensor 15 rapidly increases, the output signal of the air pressure sensor 15 changes rapidly, and the mainboard of the variable-frequency heater can read the data to perform shutdown protection.

[0055] An operating process of the variable-frequency heater includes the following steps.

[0056] (S1) A heating temperature for a heating space is set on a main control module through the temperature controller 19, and the variable-frequency heater is started.

[0057] (S2) The gas heating assembly and the fan 7 are controlled by the main control module to operate at a maximum level to deliver warm air into the heating space. A temperature probe of the temperature controller 19 detects a temperature of the heating space in real time and feeds the temperature back to the main control module. When operating at the maximum level, the gas heating assembly and the fan 7 are operated at 100% load, i.e., at maximum power.

[0058] (S3) When the real-time temperature of the heating space detected by the temperature probe reaches the set heating temperature, the gas heating assembly and the fan 7 are controlled by the main control module to enter a standby state.

[0059] (S4) When the real-time temperature of the heating space detected by the temperature probe decreases to a minimum heating temperature preset in the main control module, the gas heating assembly and the fan 7 are controlled by the main control module to operate at an automatic level. The temperature probe of the temperature controller 19 detects the temperature of the heating space in real time and feeds the temperature back to the main control module. The process then returns to step (S3) until the heater is turned off. When operating at the automatic level, the gas heating assembly and the fan 7 are operated at 40-80% load, i.e., at 40-80% of the maximum power.

[0060] (S5) A soft mode command is sent to the main control module through the temperature controller 19, where the gas heating assembly and the fan 7 are controlled by the main control module to operate at a soft level. The temperature probe of the temperature controller 19 detects the temperature of the heating space in real time and feeds the temperature back to the main control module. When operating at the soft level, the gas heating assembly and the fan 7 are operated at 30-60% load, i.e., at 30-60% of the maximum power.

[0061] (S6) When the real-time temperature of the heating space detected by the temperature probe decreases to the minimum heating temperature preset by the main control module, the process returns to step (S5) until the heater is turned off.

[0062] (S7) A sleep mode command is sent to the main control module through the temperature controller 19, under which the gas heating assembly and the fan 7 are controlled by the main control module to operate at a sleep level. The temperature probe of the temperature controller 19 detects the temperature of the heating space in real time and feeds the temperature back to the main control module. When operating at the sleep level, the gas heating assembly and the fan 7 are operated at 20-40% load, i.e., at 20-40% maximum power.

[0063] (S8) When the real-time temperature of the heating space detected by the temperature probe decreases to the minimum heating temperature preset by the main control module, the process returns to step (S5) until the heater is turned off.

[0064] In actual operation, assuming an ambient temperature of 10 C., the heating space measures 30 m.sup.2 with a height of 3 m, resulting in a volume of 90 m.sup.3. When a user enters the heating space and no heating is active, the variable-frequency heater is activated and set to a heating temperature of 20 C., corresponding to a temperature difference of 30 K relative to the ambient temperature. At this condition, the heater is operated at maximum load, i.e., at a full load of 35,000 BTU, producing a measured airflow of approximately 900 m.sup.3/h and a heating capacity of 80 K. When converted, this corresponds to an effective airflow of 2,400 m.sup.3/h to achieve a temperature rise of 30 K. The required heating time is calculated as:

[00001]$t=\frac{9060}{2400}=2\min 15s.$

[0065] After the set heating temperature is reached, the variable-frequency heater enters a standby state. When the temperature of the heating space decreases to the minimum heating temperature preset by the main control module, specifically when the temperature decreases to 17 C., the heater operates at 40% load and 40% airflow. At 40% load, the heater can produce an effective airflow of 1,200 m.sup.3/K min, which is significantly greater than a volume of the heating space. Under this condition, the heater is operated at a reduced load, such that temperature equilibrium is achieved within 5 to 15 minutes. This enables low-noise operation, low airflow and gentle delivery of warm air.

[0066] During the sleep mode, a door of the heating space remains closed, ensuring good thermal insulation. Under this condition, the heater can operate at an even lower load, i.e., at the sleep level, with a 20% load and ultra-low airflow, thereby ensuring that the operation of the heater is inaudible to the user during sleep.

[0067] The embodiments described above are merely illustrative, and are not intended to limit the scope of the present disclosure. It should be understood that various modifications, changes and replacements made by those skilled in the art without departing from the spirit of the disclosure shall fall within the scope of the present disclosure defined by the appended claims.