JP2012105595A - Hot-air heater for greenhouse horticulture and cooling control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot-air heater for greenhouse horticulture capable of optimally controlling the cooling operation of a heat exchange part according to the size of a greenhouse heating load by a simple control method, and capable of reducing the cost at the same time; and to provide a cooling control method thereof.SOLUTION: The hot-air heater 100 for greenhouse horticulture includes: the heat exchange part 110 having a combustion chamber 111 and a fire tube part 112; a burner 120 for burning a fuel inside the combustion chamber 111; a blower 130 for feeding hot air into a greenhouse by the heat exchange in the heat exchange part 110; and a control board 140. In cooling the heat exchange part 110, a control part 141 inside the control board 140 measures the burning time of the burner 120, determines a heating load condition predetermined according to the measured burning time of the burner, selects one cooling time based on the determined heating load condition from a plurality of cooling times predetermined according to the heating load conditions, and operates the blower 130 according to the selected cooling time.

Description

  The present invention relates to a warm air heater that heats the inside of a facility horticultural house with warm air, and relates to a warm air heater that enables optimization of a cooling operation of a heat exchange part (furnace body) by a blower and a cooling control method thereof. It is.

  Normally, this type of hot air heater is configured to maintain the house temperature at a set temperature (management temperature) by turning on / off a burner based on a temperature sensor installed in the house. That is, when the heating-on command or the room temperature is lower than the set temperature, combustion of the burner is started, and hot air is blown into the house by heat exchange in the heat exchanging unit, and the house is heated. Steady operation of the burner (operation where the temperature balance between combustion of the burner and heat exchange by the blower is in an equilibrium state) is maintained at the set temperature, but combustion of the burner is stopped immediately when the room temperature exceeds the set temperature. At the same time, air blow continues from the blower for a certain time (usually about 5 to 6 minutes) in order to cool the heat exchange section. By repeating such an operation, the temperature in the house is maintained at the set temperature.

  The cooling time of the furnace body (comprising a combination of a cylindrical combustion chamber and a smoke tube) that forms the heat exchanger is set by timer control based on the maximum heating load of the house (for example, winter or night). As a result, the following problems occurred.

  When the heating load of the house is small (for example, when it is used in a small house with a small load or when the load is relatively small, such as autumn or early spring), after the burner operation starts, before the furnace body is sufficiently heated In addition, the house temperature exceeds the set temperature and the cooling operation is started, and the cooling operation is performed for the same time as when the load is large, and the temperature blown from the duct into the house is reduced to near the house temperature ( In order to avoid the occurrence of obstacles such as growth delay in crops close to the duct's air vents, special arrangements were sometimes required to arrange the air vents.

  On the other hand, if the cooling time of the furnace body is shortened, if the heating load increases, the air temperature will rise, the residual temperature will be generated without lowering the furnace body temperature, and the thermal distortion of the furnace body will remain. There is a risk that problems such as cracking of the can body and equipment damage due to residual heat may occur.

  On the other hand, the applicant first provides a temperature sensor at the air outlet, and immediately stops the air blowing operation of the air blower when the air temperature of the air blower is lower than the set temperature, and stops the cooling operation of the heat exchange unit. Proposed hot air heater for facility horticulture (see Patent Document 1).

Japanese Patent No. 4344461

  Since the proposed hot air heater uses a plurality of temperature sensors provided at each air outlet (left and right or up and down) separately from the temperature sensor in the house, there is room for improvement in cost reduction.

  The present invention has been made in view of the above-mentioned problems, and it is possible to optimally control the cooling operation of the heat exchanging unit according to the size of the heating load of the house by a simple control method, and it is possible to reduce costs at the same time. An object is to provide a hot air heater for use and a cooling control method thereof.

In order to solve the above problems, a hot air heater for horticultural horticulture according to the present invention includes a heat exchange unit including a combustion chamber and a smoke tube unit, a burner for burning fuel in the combustion chamber, and heat exchange in the heat exchange unit. In the facility horticulture warm air heater equipped with a blower for supplying warm air into the house and a controller for controlling each operation of the burner and the blower,
In cooling the heat exchange unit, the burner combustion time is measured, the preset heating load condition is determined according to the measured burner burn time, and a plurality of cooling presets according to the heating load condition are determined. The main feature is that one cooling time is selected from the time according to the determined heating load condition, and the blower is operated according to the selected one cooling time.

  The facility horticultural hot air heater according to the present invention is characterized in that the control unit sets in advance a plurality of cooling times of the heat exchange unit by the blower after the combustion of the burner is stopped according to the heating load condition, and a burner The combustion time measuring means for measuring the burner combustion time from the ON signal and the OFF signal, the load condition determining means for determining the heating load condition based on the combustion time measured by the combustion time measuring means, and the load condition determining means Cooling time selection means for selecting any one of the plurality of cooling times according to the heating load condition, and operation control means for operating the blower according to the one cooling time selected by the cooling time selection means. Two features.

  The facility horticulture hot air heater according to the present invention stores each data of burner combustion time set in advance corresponding to the heating load condition and cooling time set in advance corresponding to the heating load condition A third feature is that the data storage means is provided.

A cooling control method for a hot air heater for facility horticulture according to the present invention includes a heat exchange unit including a combustion chamber and a smoke pipe unit, a burner for burning fuel in the combustion chamber, and heat exchange in the heat exchange unit in the house. In a facility horticulture warm air heater equipped with a blower for supplying warm air,
In cooling the heat exchange unit, the burner combustion time is measured, the preset heating load condition is determined according to the measured burner burn time, and a plurality of cooling presets according to the heating load condition are determined. The main feature is that one cooling time is selected from the time according to the determined heating load condition, and the blower is operated according to the selected one cooling time.

  The cooling control method for the hot air heater for facility horticulture according to the present invention is characterized in that the cooling time is made to coincide with the blowing time of the blower.

  As described above, according to the hot air heater for horticultural horticulture according to the present invention, based on the combustion time of the burner, switching control to the optimal cooling time according to the size of the heating load of the house, thereby The cooling operation of the heat exchange unit by the blower can be optimally controlled. In addition, it is possible to prevent crop growth failure near the duct outlet due to excessive cooling, and to prevent thermal distortion and equipment damage to the can of the heat exchange part due to excessive cooling time. Excellent effect.

  In addition, the sensor for measuring the air temperature near the air outlet can be eliminated, and the cost can be reduced.

  In addition, according to the cooling control method for a facility horticulture hot air heater according to the present invention, the burner combustion time is measured from the burner ON signal and the OFF signal, and based on this, the size of the heating load of the house is measured. Accordingly, it is possible to optimize the cooling operation of the heat exchanging unit by the blower, and thereby prevent crop growth failure and the like.

Sectional drawing which shows the warm air heater for facilities gardening which concerns on this invention, The figure which shows the structural example of the control part in a control panel, The figure which shows the various data stored in the data storage part of a control part, The flowchart which shows the cooling operation control of the warm air heater shown in FIG. (A) is a relationship diagram between burner on / off control and furnace surface temperature in high load operation, and (B) is a relationship diagram between burner on / off control and furnace surface temperature in low load operation.

  An embodiment for carrying out the present invention will be described with reference to FIGS. In FIG. 1, 100 is a warm air heater for facility horticulture.

  As shown in FIG. 1, the facility horticulture warm air heater 100 includes a casing 101 in which a heat exchange unit (furnace) 110 in which a cylindrical combustion chamber 111 and a smoke tube unit 112 are combined is disposed. The chimney 114 extends through the smoke chamber 113. A nozzle portion 121 of a burner 120 is disposed in the combustion chamber 111. A plurality of blowers 130, 130 are disposed on the upper surface of the casing 101, and a control panel 140 is disposed on the side surface of the casing 101.

  The facility horticultural hot air heater 100 ignites and burns fuel sprayed from the nozzle portion 121 of the burner 120 into the combustion chamber 111 by an ignition device, and the hot exhaust gas G passes through the smoke pipe portion 112 and the smoke chamber 113. While exhausting from the chimney 114, each fan 130 is operated to take in the air in the house, heat is exchanged in the heat exchanging unit 110, and the generated warm air K is discharged from the discharge port 102 below the casing 101 through a duct (not shown). It is designed to be discharged into the house.

  Then, after the combustion operation of the burner 120 starts, when the house temperature rises and exceeds the set temperature (operation width 1 ° C.), the control panel 140 is detected by a temperature signal detected from a temperature sensor (not shown) of the house temperature. When an off signal is output from the control unit to the burner 120, the combustion of the burner 120 stops, the temperature in the house decreases, and reaches the set temperature, the control unit of the control panel 140 is detected by the detected temperature signal from the temperature sensor. An ON signal is output from 141 to the burner 120, and the burner 120 burns again. In this way, the burner 120 is repeatedly burned and stopped by the ON signal and the OFF signal from the control unit, and the house temperature is maintained at the set temperature (see FIG. 5). Here, burning and stopping of the burner 120 are specifically performed by opening and closing an electromagnetic valve provided in the fuel passage by an ON signal / OFF signal from the control unit 141.

  FIG. 2 shows a configuration example of the control unit 141 of the control panel 140. The control unit 141 includes a program storage unit 142, a data storage unit 143, a combustion time measurement unit 144, a load condition determination unit 145, a cooling time selection unit 146, and an operation control unit 147.

  The program storage unit 142 stores a program for performing cooling operation control according to the flowchart of FIG. In the data storage unit 143, as shown in FIG. 3, the heating load condition (high load operation / medium load operation / low load operation / no load) and a plurality of burners 120 set in advance corresponding to the heating load condition are stored. A combination of each data of the combustion time and a plurality of preset cooling times corresponding to the heating load conditions is stored. The combustion time measuring unit 144 measures the actual combustion time of the burner 120. Specifically, the combustion time measuring unit 144 measures the opening / closing (on / off) time of an electromagnetic valve provided in the fuel passage, and uses the opening / closing time as the combustion time. And

  As can be seen from FIGS. 5A and 5B, in the case of low load operation (FIG. 5B), compared to the case of high load operation (FIG. 5A), the heating and heating after burner-on are performed. The time to reach the set temperature of the house internal temperature is early, therefore the combustion time of the burner 120 is short, and the cooling time of the heat exchange part (furnace body) after the burner is off is also shortened in proportion to the combustion time (in addition, In the graph showing the change in the furnace body surface temperature in FIG. 5B, the dotted line shows the change in the furnace body surface temperature in the case of the conventional (timer)).

  Based on the facts described above, the control unit 141 sets the combustion time of the burner 120 in advance (for 20 minutes or more) corresponding to the heating load condition (high load operation / medium load operation / low load operation / no load). 15 to less than 20 minutes, less than 1 to 15 minutes and less than 1 minute), and a plurality of cooling times (5 minutes, 4 minutes, 3 minutes, 0 minutes) are set in advance, and the actual burner 120 measured From the combustion time, the heating load condition is determined, and based on the determined load condition, the optimum cooling time is selected from a plurality of cooling times, thereby optimizing the cooling operation of the heat exchange unit 120 by the blower 130 It comes to control.

  The load condition determination unit 145 determines a heating load condition (high load operation / medium load operation / low load operation / no load) based on the measured combustion time of the burner 120. The cooling time selection unit 146 selects an optimal cooling time from the plurality of cooling times stored in the data storage unit 143 according to the heating load condition determined by the load condition determination unit 145.

  The operation control unit 147 outputs an on / off control signal to the burner 120 by a temperature signal transmitted from a temperature sensor in the house (not shown), and controls the burner 120 on / off operation (opens / closes the solenoid valve). At the same time, according to the one cooling time selected by the cooling time selector 146, the cooling operation of the fans 130 and 130 is controlled.

  In the hot air heater 100 configured as described above, a control method for cooling the heat exchanging unit 110 will be described with reference to the flowchart of FIG.

  In accordance with the heating-on command, the burner 120 and each blower 130 of the hot air heater 100 are activated and operation control is started. Then, based on the temperature signal from the temperature sensor in the house, the solenoid valve provided in the fuel passage is opened and closed by a control signal from the operation control unit 145 of the control unit 141 so that the temperature in the house maintains the set temperature ( ON / OFF) operation is performed, and thereby the burner 120 is ON / OFF controlled.

  At this time, the combustion time of the burner 120 is measured in the combustion time measuring unit 144 according to the on / off signal of the solenoid valve. Further, according to the OFF signal of the electromagnetic valve, the burner 120 is stopped by the control signal from the operation control unit 147, and the cooling operation control of the blowers 130 and 130 is started.

  In the control unit 141, based on the measured combustion time, the load condition determination unit 145 performs high load operation (combustion time 20 minutes or more), medium load operation (less than 15-20 minutes), and low load operation (1 to 2). Less than 15 minutes) or no load (less than 1 minute), and the cooling time selection unit 146 determines the optimal cooling time corresponding to the determined heating load condition from the data storage unit 143. select.

  When it is determined that the operation is high load (combustion time 20 minutes or more) (for example, in winter), after the burner 120 is stopped, the blower operation of each blower 130 is started again by the control signal from the operation control unit 147, and the longest time The air blowing operation is performed (for 5 minutes), and then each air blower 130 is stopped, whereby the cooling operation control is stopped.

  Similarly, when it is determined that the operation is medium load (less than 15 to 20 minutes) (for example, in the daytime in winter), after the burner 120 is stopped, the blower operation of each blower 130 is started again by the control signal from the operation control unit 147. Then, the air blowing operation is performed for a medium time (four minutes), and then each air blower 130 is stopped, whereby the cooling operation control is stopped.

  Similarly, when it is determined that the load is low (combustion time is less than 1 to 15 minutes) (for example, early spring or autumn), after the burner 120 is stopped, the blower operation of each blower 130 is again performed by a control signal from the operation control unit 147. Is started, and the air blowing operation is performed for a short time (3 minutes), and then each air blower 130 is stopped, whereby the cooling operation control is stopped.

  When it is determined that there is no load (combustion time less than 1 minute) (for example, trial operation, inspection), after the burner 120 is stopped, the air blowing operation of each blower 130 is immediately stopped by the control signal from the operation control unit 147. Cooling operation control is stopped.

  When the operation (combustion) of the burner 120 is started again based on the temperature sensor in the house, the combustion time of the burner 120 is measured according to the on / off signal of the solenoid valve, and the cooling operation control of each blower 130 is started. The

  According to the hot air heater 100 of the present embodiment, the combustion time by the on / off signal of the burner 120 is measured, thereby selecting and switching the optimal cooling time according to the size of the heating load of the house. The cooling operation of the heat exchange unit 110 by the blower 130 can be optimally controlled.

  In addition, according to the warm air heater 100, the execution of the cooling control method described above prevents the crop from growing near the duct outlet due to excessive cooling, and the can of the heat exchange section due to the excessive cooling time. It is possible to prevent thermal distortion to the body and equipment damage.

  The hot air heater for facility horticulture according to the present invention can be widely used as a hot air heater for controlling the cooling operation of the heat exchanging unit by the blower.

DESCRIPTION OF SYMBOLS 100 Hot air heater for gardening 101 Casing 102 Discharge port 110 Heat exchange part 111 Combustion chamber 112 Smoke pipe part 113 Smoke room 114 Chimney 120 Burner 121 Nozzle part 130 Blower 140 Control board 141 Control part 142 Program storage part 143 Data storage part 144 Combustion time measurement unit (combustion time measurement means)
145 Load condition determination unit (load condition determination means)
146 Cooling time selection unit (cooling time selection means)
147 Operation control unit (operation control means)

Claims (5)

Each operation of the heat exchanger having a combustion chamber and a smoke tube, a burner for burning fuel in the combustion chamber, a fan for supplying warm air into the house by heat exchange in the heat exchanger, and each operation of the burner and fan In the facility horticulture hot air heater equipped with a control unit to control,
In cooling the heat exchange unit, the burner combustion time is measured, the preset heating load condition is determined according to the measured burner burn time, and a plurality of cooling presets according to the heating load condition are determined. From the time, one cooling time is selected according to the determined heating load condition, and the blower is operated according to the selected one cooling time,
Hot air heater for horticulture.   The control unit measures a combustion time of the burner from a cooling time setting means for setting a plurality of cooling times of the heat exchange unit by the blower after the combustion of the burner is stopped in advance according to the heating load condition, and a burner ON signal and an OFF signal. Any one of the plurality of cooling times according to the combustion load measuring means, the load condition determining means for determining the heating load condition based on the combustion time measured by the combustion time measuring means, and the heating load condition determined by the load condition determining means 2. The facility horticultural hot air heater according to claim 1, further comprising: a cooling time selection means for selecting one of the two, and an operation control means for operating the blower according to the one cooling time selected by the cooling time selection means. .   The data storage means for storing each data of the combustion time of the burner set beforehand corresponding to heating load conditions, and the cooling time set up plurally beforehand corresponding to heating load conditions, It is characterized by the above-mentioned. The hot air heater for facility horticulture according to claim 1 or claim 2. Facility horticultural hot air heater comprising a heat exchange section having a combustion chamber and a smoke tube section, a burner for burning fuel in the combustion chamber, and a blower for supplying warm air into the house by heat exchange in the heat exchange section In
In cooling the heat exchange unit, the burner combustion time is measured, the preset heating load condition is determined according to the measured burner burn time, and a plurality of cooling presets according to the heating load condition are determined. From the time, one cooling time is selected according to the determined heating load condition, and the blower is operated according to the selected one cooling time,
Cooling control method for hot air heater for horticulture.   The cooling control method for a facility horticulture warm air heater according to claim 4, wherein the cooling time is made to coincide with the blowing time of the blower.

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