JP2013217521A - Latent heat recovery type evaporative water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a latent heat recovery type evaporative oil water heater which prevents freezing of retained water inside heat receiving tubes without providing a dedicated heater for preventing freezing which heats the heat receiving tubes of a primary heat exchanger and a secondary heat exchanger.SOLUTION: In a latent heat recovery type evaporative oil water heater 1 which includes a burner configured with an evaporating unit 7 which has heaters 4 and 6 for heating and which evaporates a fuel, and a combustion unit 10 which combusts the fuel evaporated at the evaporating unit 7, a primary heat exchanger 23 which recovers sensible heat from a combustion gas generated by combustion of the burner to heat water flowing through a primary heat receiving tube 22, a secondary heat exchanger 25 which recovers latent heat from the combustion gas which has passed through the primary heat exchanger 23 to heat water flowing through a secondary heat receiving tube 24, and a temperature detecting unit 36 which detects a freezing prevention temperature, in which the primary heat exchanger 23 is arranged above the burner, and the secondary heat exchanger 25 are arranged above the primary heat exchanger 23, and when the freezing prevention temperature is detected upon stop of operation of the latent heat recovery type evaporative oil water heater 1, the heaters 4 and 6 for heating are powered on.

Description

  The present invention relates to the prevention of freezing of a latent heat recovery type vaporized petroleum hot water supply apparatus.

  In a conventional hot water supply apparatus, in order to improve heat exchange efficiency, a primary heat exchanger that recovers sensible heat from combustion gas generated by combustion of a burner and heats water flowing through a primary heat receiving pipe, and a primary heat exchanger are provided. A latent heat recovery type hot water supply apparatus having a secondary heat exchanger that recovers latent heat from the combustion gas after passing through and heats water flowing through a secondary heat receiving pipe has become widespread.

  In such a latent heat recovery type hot water supply apparatus, in order to prevent the water in the primary heat receiving pipe of the primary heat exchanger from freezing, a heater for freezing prevention is added to the primary heat receiving pipe (for example, refer to Patent Document 1). Anti-freezing heaters are used to prevent freezing in low-temperature environments. To prevent freezing of water in the secondary heat receiving pipe of the secondary heat exchanger, an anti-freezing heater is added to the secondary heat receiving pipe. (For example, refer to Patent Document 2), there are some that use a freeze prevention heater to prevent freezing in a low temperature environment.

JP 2006-105468 A JP 2000-199648 A

  By the way, in this latent heat recovery type hot water supply apparatus, freezing of water in the primary heat receiving pipe of the primary heat exchanger and water in the secondary heat receiving pipe of the secondary heat exchanger can be prevented by using a freezing prevention heater. However, in order to prevent the water in the primary heat receiving pipe and the water in the secondary heat receiving pipe from freezing, a dedicated anti-freezing heater must be provided, and the parts cost is reduced by the addition of the anti-freezing heater. In addition to the increase in the number of components, the assembly of the anti-freezing heater is increased, which complicates the work, and further increases the risk of component failure.

  In order to solve the above-described problems, the present invention is particularly configured in claim 1 by a vaporization section that includes a heater and vaporizes the fuel oil, and a combustion section that burns the fuel oil vaporized by the vaporization section. A burner, a primary heat exchanger that recovers sensible heat from the combustion gas generated by the combustion of the burner and heats water flowing through the primary heat receiving pipe, and the combustion gas after passing through the primary heat exchanger A secondary heat exchanger that recovers the latent heat and heats the water flowing through the secondary heat receiving pipe; and a temperature detecting means that detects a freezing prevention temperature, and the primary heat exchanger is disposed above the burner, A latent heat recovery vaporization type petroleum hot water supply apparatus in which the secondary heat exchanger is disposed above a primary heat exchanger, wherein an operation switch of a remote control for remotely operating the latent heat recovery type vaporization type petroleum hot water supply apparatus is turned off, Latent heat recovery type vaporized oil water heater When the operation is stopped or when the temperature detecting means detects the antifreeze temperature was assumed to turn on the heater.

  According to the first aspect of the present invention, when the operation switch of the remote controller for remotely operating the latent heat recovery type vaporization type petroleum hot water supply device is turned off and the operation of the latent heat recovery type vaporization type petroleum hot water supply device is stopped, the temperature detection means However, when the anti-freezing temperature is detected, the heater is turned on to heat the vaporizing section and the burner. The air heated by the burner rises and heats the primary heat receiving pipe and the secondary heat receiving pipe located above the burner, so that the water staying in the primary heat receiving pipe and the water staying in the secondary heat receiving pipe are frozen. Can be reliably prevented, and it is not necessary to provide a dedicated anti-freezing heater for preventing freezing of water in the primary heat receiving pipe and the secondary heat receiving pipe. Assembly work can be eliminated, and the risk of component failure can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows the latent-heat-recovery type vaporization type hot water supply apparatus of one Embodiment of this invention.

Next, a hot water supply apparatus according to an embodiment of the present invention will be described with reference to FIG.
Reference numeral 1 denotes a latent heat recovery type vaporization type oil hot water supply apparatus of the present embodiment, 2 denotes an aluminum die-cast vaporizer that vaporizes fuel such as petroleum, and has a vaporized gas outlet 3 at the bottom of the vaporizer 2. Is. A vaporizer heater 4 is provided in the vaporizer 2 and heats the fuel oil to a temperature at which vaporization can be vaporized. A vaporizer 5 is connected to the outlet 3 at the lower portion of the vaporizer 2 and is vaporized in the vaporizer 2 and primary. An aluminum die-cast mixing chamber 6 for premixing with air is provided at the bottom of the mixing chamber 5 to heat the mixing chamber 5 and prevent liquefaction of the vaporized gas flowing in from the outlet 3 to promote vaporization. A vaporizing section 7 for vaporizing fuel oil is formed by the vaporizer 2 and the mixing chamber 5 described above.

  8 is a vaporizing temperature sensor for detecting the temperature of the vaporizer 2, 9 is a mixing chamber temperature sensor for detecting the temperature of the mixing chamber 5, and 10 is provided on the back side of the vaporizer 2 above the mixing chamber 5. In the combustion section that burns the premixed premixed gas, the combustion section 10 and the vaporization section 7 constitute a burner. Reference numeral 11 denotes a plurality of endothermic fins that are formed integrally with the carburetor 2 and project on the combustion unit 10 at the back of the carburetor 2. During combustion, the combustion heat is fed back to the carburetor 2 as vaporization heat and vaporized. The energization amount of the heater 4 is suppressed as much as possible.

  12 is a nozzle for spraying fuel oil on the vaporizer 2, 13 is an electromagnetic pump for pumping fuel oil to the nozzle 12 via an oil feed pipe 14, 15 is a combustion fan, and an inlet and a combustion section of the vaporizer 2 via an air passage 16. Combustion air that is communicated with the air chamber 18 between the cover 10 and the cover frame 17 and sucked from the suction port 19 is supplied to the carburetor 2 as primary air for premixing, and the carburetor 2 is supplied to the air chamber 18. It is supplied as secondary air that passes through the side and is combusted in the combustion section 10 from below the mixing chamber 5.

  20 is a heat exchanger accommodated in the combustion chamber 21, and this heat exchanger 20 collects sensible heat from the combustion gas generated by the combustion of the combustion unit 10 and heats the water flowing through the primary heat receiving pipe 22. It is composed of a tube-type primary heat exchanger 23 and a secondary heat exchanger 25 that recovers latent heat from the combustion gas after passing through the primary heat exchanger 23 and heats water flowing through the secondary heat receiving pipe 24, A primary heat exchanger 23 is disposed above the combustion unit 10, and a secondary heat exchanger 25 is disposed above the primary heat exchanger 23, and the primary heat exchanger 23 and the secondary heat exchanger 25 are disposed. The combustion gas that has passed through in this order is exhausted out of the hot water supply device 1 through the exhaust port 26.

  27 is a drain receiver that recovers the drain that is generated when the water vapor in the combustion gas exchanges heat with the water flowing through the secondary heat receiving pipe 24 of the secondary heat exchanger 25 to a temperature below the dew point. 27 is disposed above the primary heat exchanger 23 and below the secondary heat exchanger 25, and here, a corrosion-resistant housing (not shown) constituting the secondary heat exchanger 25. The bottom plate is a drain receiver 27. Reference numeral 28 denotes a drain pipe for guiding the drain collected by the drain receiver 27 to the neutralizing device 29.

  30 is a water supply pipe for circulating water supplied from a water supply source to the heat exchanger 20, 31 is for circulating hot water heated by the heat exchanger 20, and hot water is supplied to a hot water tap (not shown) provided at a predetermined location. The hot water supply pipe 32 is a water supply bypass pipe branched from the water supply pipe 30, and the hot water supply water flows through the primary heat receiving pipe 22, the secondary heat receiving pipe 24, the water supply pipe 30, the hot water supply pipe 31, and the water supply bypass pipe 32. It constitutes a circuit.

  A mixing valve 33 is provided at a connection portion between the hot water supply pipe 31 and the water supply bypass pipe 32, mixes hot water from the hot water supply pipe 31 and water from the water supply bypass pipe 32, and varies a mixing ratio thereof. 30 is a water supply temperature sensor serving as a temperature detecting means for detecting the water supply temperature, 35 is a flow sensor for detecting the flow rate provided in the water supply pipe 30, and 36 is a hot water provided in the hot water supply pipe 31 and heated by the heat exchanger 20. Reference numeral 37 denotes a heat exchange outlet temperature sensor as temperature detecting means for detecting the temperature of the hot water, and reference numeral 37 denotes a hot water supply temperature sensor as temperature detecting means for detecting the temperature of the hot water provided in the hot water supply pipe 31 and mixed by the mixing valve 33.

  38 is a control means for controlling the driving of the actuators such as the vaporizer heater 4, the mixing chamber heater 6 and the combustion fan 15 by receiving signals from the sensors of the latent heat recovery type vaporized petroleum hot water supply apparatus 1 mainly using a microcomputer. It is.

  A remote control 39 is communicably connected to the control means 38 and remotely controls the latent heat recovery vaporization type petroleum hot water supply apparatus 1. The remote control 39 is an operation for instructing on / off of the operation of the latent heat recovery type vaporization petroleum hot water supply apparatus 1. An operation unit 41 including a switch 40, a hot water supply temperature setting switch for setting a hot water supply temperature, and a display unit 42 for displaying the state of the latent heat recovery type vaporized petroleum hot water supply device 1 and the hot water supply set temperature. It is.

Next, the operation of the latent heat recovery type vaporized petroleum hot water supply device 1 of this embodiment will be described.
When the operation switch 40 of the remote control 39 is turned on, the control means 38 controls the vaporizer heater 4 based on the temperature detected by the vaporization temperature sensor 8 and mixes based on the temperature detected by the mixing chamber temperature sensor 9. The chamber heater 6 is controlled to preheat the vaporizer 2 and the mixing chamber 5, the temperature at which the vaporizer 2 can vaporize the fuel oil, for example, the temperature of the vaporizer 2 is maintained at 220 ° C. to 250 ° C. It will be in the standby state in which temperature is maintained at 125 to 130 degreeC. In this standby state, when a combustion request is generated, the burner can be ignited quickly, and the power consumption during standby can be reduced by maintaining the necessary minimum temperature.

  In the standby state, when the hot water tap is opened and the flow rate sensor 35 detects a flow rate equal to or higher than the minimum operating flow rate and the control means 38 determines that a combustion request has occurred, the vaporizer heater 4 and the mixing chamber heater 6 are turned on. The ignitability is improved by forcibly turning on, the electromagnetic pump 13 and the combustion fan 15 are driven, the vaporized gas vaporized in the vaporizer 2 and the primary air are premixed in the mixing chamber 5, and the premixed gas is It is ejected from the combustion section 10 to start combustion.

  The combustion gas generated by the combustion of the burner flows through the primary heat exchanger 23, passes through the primary heat exchanger 23, passes through the secondary heat exchanger 25, and passes through the secondary heat exchanger 25. The exhaust gas is discharged from the exhaust port 26 to the outside of the latent heat recovery-type vaporized petroleum water heater 1. Further, the water supplied from the water supply source is led from the water supply pipe 30 to the secondary heat receiving pipe 24 and flows in order from the secondary heat receiving pipe 24 to the primary heat receiving pipe 22 where it is heated by heat exchange with the combustion gas. Then, the hot water led from the primary heat receiving pipe 22 to the hot water supply pipe 31 and adjusted to the hot water supply set temperature by adjusting the opening of the mixing valve 33 is finally supplied from the hot water tap.

  At this time, in the secondary heat exchanger 25, the water flowing through the secondary heat receiving pipe 24 and the combustion gas are subjected to heat exchange, and the drain generated by the water vapor in the combustion gas being below the dew point is the drain receiver 27. It is collected and flows through a drain pipe 28 into a neutralizing device 29 filled with a neutralizing agent, neutralized in the neutralizing device 29, and then discharged to the outside of the neutralizing device 29. It is drained into the sewage.

  Next, the situation of the latent heat recovery type vaporization type petroleum hot water supply device 1 in a low temperature environment will be described. When the outside air temperature is low in winter or the like, the operation switch 40 of the remote control 39 is turned off and the latent heat recovery type vaporization type is obtained. When the operation of the oil hot water supply device 1 is stopped for a long time, the temperature in the latent heat recovery vaporization type oil hot water supply device 1 approximates to the outside air temperature outside the latent heat recovery type vaporization type oil hot water supply device 1 and is primary. Since there is no circulation of water in the heat receiving pipe 22 and the secondary heat receiving pipe 24, the water staying in the primary heat receiving pipe 22 and the secondary heat receiving pipe 24 may be frozen.

  Here, as described above, when the operation switch 40 of the remote control 39 is turned off and the operation of the latent heat recovery vaporization type petroleum hot water supply device 1 is stopped, the temperature detected by the heat exchange outlet temperature sensor 36 is frozen. When the preset anti-freezing temperature is detected, the control means 38 turns on the vaporizer heater 4. Then, the vaporizer 2 is heated by the vaporizer heater 4, the heat of the vaporizer 2 is transferred to the combustion unit 10 and the heat absorption fins 11, and is efficiently dissipated through the combustion unit 10 and the heat absorption fins 11. The air on the combustion unit 10 is heated. The heated air rises into the combustion chamber 21 and heats the primary heat receiving pipe 22 and the secondary heat receiving pipe 24 located in the combustion chamber 21 above the combustion section 10, that is, above the burner. Thereby, it is possible to reliably prevent freezing of the water staying in the primary heat receiving pipe 22 and the water staying in the secondary heat receiving pipe 24, and the vaporizer heater provided in the vaporizer 2 for vaporizing the fuel oil. 4 is used for anti-freezing, so it is not necessary to provide a dedicated anti-freezing heater for preventing freezing of water in the primary heat receiving pipe 22 and the secondary heat receiving pipe 24, and the cost of parts can be reduced. The assembly work of the prevention heater can be made unnecessary, and further, the risk of component failure can be reduced since it is not necessary to provide a freeze prevention heater.

  The present invention is not limited to the above-described embodiment. In this embodiment, the temperature detection means for detecting the antifreezing temperature is the heat exchange outlet temperature sensor 36, but the temperature detection means is Whether the water staying in the primary heat receiving pipe 22 and the secondary heat receiving pipe 24 may freeze when the outside air temperature is low and the operation of the latent heat recovery type vaporized petroleum water heater 1 is stopped in winter or the like What is necessary is just to be able to detect the temperature for judging whether or not, and instead of the heat exchange outlet temperature sensor 36, the water supply temperature sensor 34 and the hot water supply temperature sensor 37 in the latent heat recovery type vaporized hot water supply apparatus 1 are prevented from freezing. The temperature detecting means for detecting the temperature may be used, or a dedicated temperature sensor for detecting the ambient temperature in the latent heat recovery type vaporized petroleum hot water supply apparatus 1 may be provided and used as a temperature detecting means for detecting the anti-freezing temperature. good thing A.

  In the present embodiment, the vaporizer heater 4 is turned on when the temperature detected by the heat exchange outlet temperature sensor 36 detects a preset anti-freezing temperature that may cause freezing. The mixing chamber heater 6 may be turned on instead of the heater 4, and by doing so, the mixing chamber 5 is heated by the mixing chamber heater 6 and the air in the mixing chamber 5 is heated. Then, the heated air rises into the combustion chamber 21 through the combustion section 10 at the top of the mixing chamber 5, and the primary heat receiving pipe 22 and the second pipe located in the combustion chamber 21 above the combustion section 10, that is, above the burner. The next heat receiving pipe 24 is heated. As a result, similarly to when the vaporizer heater 4 is turned on, it is possible to reliably prevent freezing of the water staying in the primary heat receiving pipe 22 and the water staying in the secondary heat receiving pipe 24, and the bottom of the mixing chamber 5 Since the mixing chamber heater 6 provided in the above is used for antifreezing, it is not necessary to provide a dedicated antifreezing heater for preventing freezing of the water in the primary heat receiving pipe 22 and the secondary heat receiving pipe 24, thereby reducing the component cost. In addition to being able to suppress, it is possible to eliminate the work of assembling the anti-freezing heater, and further, since it is not necessary to provide the anti-freezing heater, the risk of component failure can be reduced.

DESCRIPTION OF SYMBOLS 1 Latent heat recovery type vaporization type petroleum hot water supply device 2 Vaporizer 4 Vaporizer heater 5 Mixing chamber 6 Mixing chamber heater 7 Vaporization unit 10 Combustion unit 22 Primary heat receiving pipe 23 Primary heat exchanger 24 Secondary heat receiving pipe 25 Secondary heat exchanger 36 Heat exchange outlet temperature sensor 39 Remote control 40 Operation switch

Claims (1)

  A sensible heat is recovered from the combustion gas generated by combustion of the burner comprising a heater for heating and a vaporizing section for vaporizing the fuel oil, a combustion section for burning the fuel oil vaporized in the vaporization section, and primary A primary heat exchanger that heats water flowing through the heat receiving pipe, and a secondary heat exchanger that recovers latent heat from the combustion gas after passing through the primary heat exchanger and heats the water flowing through the secondary heat receiving pipe. A latent heat recovery type vaporization type comprising: a temperature detection means for detecting an anti-freezing temperature; the primary heat exchanger is disposed above the burner; and the secondary heat exchanger is disposed above the primary heat exchanger. When the operation switch of the remote controller for remotely operating the latent heat recovery type vaporization type petroleum hot water supply device is turned off and the operation of the latent heat recovery type vaporization type petroleum hot water supply device is stopped, the temperature detection means Detects the anti-freezing temperature. If you, latent heat recovery type evaporative oil water heater is characterized in that so as to turn on the heater.

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