Air heating apparatus

Abstract

Disclosed is an air heating apparatus including a burner configured to cause a combustion reaction, a heat exchanging device configured to receive heat from combustion gas generated by the combustion reaction and heat water, a heating heat exchanger configured to receive the water heated by the heat exchanging device and exchange heat with the air for heating, a main passage, in which the heat exchanging device and the heating heat exchanger are disposed, and configured such that the water flows therethrough while circulating, and a fan configured to blow the air to the heating heat exchanger.

What is claimed is: 
     
         1 . An air heating apparatus comprising:
 a burner configured to cause a combustion reaction;   a heat exchanging device configured to receive heat from combustion gas generated by the combustion reaction and heat water;   a heating heat exchanger configured to receive the water heated by the heat exchanging device and exchange heat with the air for heating;   a main passage, in which the heat exchanging device and the heating heat exchanger are disposed, and configured such that the water flows therethrough while circulating;   a fan configured to blow the air to the heating heat exchanger; and   a processor configured to control a temperature of the water that passes through the heating heat exchanger through the main passage and returns to the heat exchanging device.   
     
     
         2 . The air heating apparatus of  claim 1 , wherein the processor is configured to:
 control a temperature of the returning water by controlling a flow rate of the water.   
     
     
         3 . The air heating apparatus of  claim 2 , further comprising:
 a water temperature acquiring device electrically connected to the processor and configured to acquire the temperature of the returning water,   wherein the processor is configured to:   control a flow rate of the water based on a preset temperature and an acquisition temperature that is the temperature acquired by the water temperature acquiring device.   
     
     
         4 . The air heating apparatus of  claim 3 , wherein the processor is configured to:
 control such that the flow rate of the water is decreased when the acquisition temperature is higher than the preset temperature.   
     
     
         5 . The air heating apparatus of  claim 2 , further comprising:
 a flow rate control valve disposed in the main passage such that the flow rate of the water that flows along the main passage is adjusted through opening and closing thereof, and electrically connected to the processor to be controlled.   
     
     
         6 . The air heating apparatus of  claim 2 , further comprising:
 a pump disposed in the main passage to pump the water,   wherein the pump is electrically connected to the processor.   
     
     
         7 . The air heating apparatus of  claim 2 , wherein the processor is electrically connected to the burner to adjust a calorie generated in the combustion reaction through control of the combustion reaction caused by the burner. 
     
     
         8 . The air heating apparatus of  claim 7 , further comprising:
 an air temperature acquiring device electrically connected to the processor and configured to acquire a temperature of the returning air; and   a flow rate acquiring device electrically connected to the processor and configured to acquire a flow rate of the water that flows through the main passage,   wherein the processor is configured to:   control the flow rate and the calorie of the water based on a mapping table, in which the temperature of the returning air, the flow rate and the calorie of the water correspond to each other, and a preset temperature.   
     
     
         9 . The air heating apparatus of  claim 1 , wherein the heat exchanging device includes:
 a sensible heat exchanger configured to receive the heat generated by the combustion reaction and heat the water that flows through an interior thereof; and   a latent heat exchanger configured to heat the water that flows through an interior thereof by using latent heat of the combustion gas generated through the combustion reaction.   
     
     
         10 . The air heating apparatus of  claim 9 , wherein the sensible heat exchanger and the latent heat exchanger are disposed in the main passage such that the water is introduced into the sensible heat exchanger via the latent heat exchanger,
 wherein the processor is configured to control such that the temperature of the water returning to the heat exchanging device is maintained in a temperature that is lower than or equal to the preset water temperature, and   wherein the preset water temperature is lower than a maximum water temperature of the water temperature of the water returning to the latent heat exchanger, by which the combustion gas is condensed in the latent heat exchanger.   
     
     
         11 . The air heating apparatus of  claim 1 , further comprising:
 an air temperature acquiring device electrically connected to the processor and configured to acquire a temperature of the returning air;   a flow rate acquiring device electrically connected to the processor and configured to acquire a flow rate of the water that flows through the main passage; and   a case, in which the processor, the burner, the heat exchanging device, the heating heat exchanger, the fan, the air temperature acquiring device, and the flow rate acquiring device are embedded,   wherein the processor is configured to:   control the temperature of the returning water based on the temperature acquired by the air temperature acquiring device and the flow rate acquired by the flow rate acquiring device.   
     
     
         12 . The air heating apparatus of  claim 1 , further comprising:
 a water inlet port communicated with the main passage to supplement water in the main passage; and   a check valve configured to allow the water to be supplemented in the main passage through the water inlet port and prevent the water from reversely flow from the main passage through the water inlet port.   
     
     
         13 . The air heating apparatus of  claim 1 , further comprising:
 a case, in which the burner, the heat exchanging device, the heating heat exchanger, and the fan are embedded,   wherein the heating heat exchanger is disposed adjacent to an upper wall of the case, and   wherein the fan is disposed on a lower side of the heating heat exchanger such that the air is blown upward to pass through the heating heat exchanger.   
     
     
         14 . The air heating apparatus of  claim 1 , further comprising:
 a case, in which the burner, the heating exchanging device, and the heating heat exchanger are embedded; and   an expansion tank embedded in the case, and connected to the main passage to accommodate a change of a volume of the water.   
     
     
         15 . The air heating apparatus of  claim 1 , wherein the heating heat exchanger includes:
 a heat exchange tube, through which the water heated by the heat exchanging device flows to exchange heat with the air that flows a periphery thereof.   
     
     
         16 . The air heating apparatus of  claim 15 , wherein the heat exchange tube forms a plurality of layers disposed at different locations according to a specific direction such that the introduced water flows along the specific direction to be discharged, and
 wherein the specific direction is an opposite direction to a direction, in which the fan sends the air.   
     
     
         17 . The air heating apparatus of  claim 15 , wherein the heat exchange tube forms a passage including a section of a parallel passage including a plurality of partial passages, inlets and outlets of which are common. 
     
     
         18 . The air heating apparatus of  claim 1 , further comprising:
 a relief valve connected to the main passage to be opened such that a pressure of the main passage is lowered to a threshold value or less when the pressure of the main passage is higher than the threshold value.   
     
     
         19 . The air heating apparatus of  claim 1 , wherein the heat exchanging device is located on a lower side of the heating heat exchanger, and
 the air heating apparatus further includes a water lack determining device disposed at an identification point that is one site between the heat exchanging device and the heating heat exchanger on the main passage such that it is identified whether the water is full at the identification point.