JP2839067B2 - Control method of road surface snow melting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a snow melting device for a road surface, a method in which hot water heated by a heat pump heat source device is circulated to a hot water tank by a circulation pump, and a part of the hot water in the hot water tank is fed by a water pump. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a hot water circulation system between a heat pump heat source device and a water storage tank in a road surface snow melting apparatus having a structure of circulating through a road surface pipe provided on a snow melting road surface.

[0002]

2. Description of the Related Art Conventionally, as this type of snow melting apparatus on a road surface,
For example, Literature: Yuichi Kobayashi et al., "Air Heat Source Heat Pump Type Road Heating Demonstration Test", "Cool Region Technology Symposium '87 Lecture Papers" (November 18, 1987, November 1987).
(20th), pp. 209-214, an example of which is proposed.

FIG. 2 is a schematic block diagram showing the configuration of an example of the conventional road surface snow melting apparatus, and FIGS. 3A and 3B are control flowcharts showing the control method. This conventional device is a device of a four-element control type, and controls on / off of a heat source device by measuring outside air temperature, road surface temperature, presence or absence of snowfall, and road surface moisture with a sensor. For this reason,
The control of the temperature of the hot water flowing through the road surface pipe was not actively performed. In the figure, reference numeral 10 denotes a heat source unit, which generally uses a hot water boiler, an electric heat pump, or the like. In this conventional example, the heat source device 10 is a heat pump using an electric method, and the heat source device 10 supplies heated hot water to a hot water storage tank 14 via an upstream circulation pipe 12a.
The hot water 16 stored in the hot water storage tank 14 is returned to the heat source device 10 by a circulation pump 18 provided in the downstream circulation pipe 12b. On the other hand, a part of the hot water 16 stored in the hot water storage tank 14 is supplied to the upstream water supply pipe 22 by the water supply pump 20.
a, It is returned to the hot water storage tank via the road surface pipe 22b and the downstream pipe 22c buried in the snow melting road surface.

[0004] Hot water 1 in a hot water storage tank 14 which is a heat pump system
6 is controlled by a temperature sensor 24 and a hot water temperature controller 26.
Mainly with. As it can be understood from the control flow shown in FIG. 3 (A), may be set the hot water of the proper temperature in the hot water tank 14 (or target temperature) e.g. T _o and (° C.), the hot water storage tank temperature sensors 24 Downstream water pipe 2 in 14
Current temperature T (° C) near the inflow of return hot water from 2c
Is measured, the hot water temperature controller 26 compares the measured temperature T with the set temperature T _O, and outputs a start / stop signal to the heat source device 10 according to the result of the comparison. That is, the controller 26 stops the heat source device 10 when the hot water temperature is higher, and generates a signal to drive the heat source device 10 when the hot water temperature is lower.

On the other hand, the temperature control on the snow melting road surface in the road heating system detects the outside air temperature, snowfall, road surface moisture and road surface temperature by respective sensors (these sensors are collectively shown as a sensor unit 28 in the figure). to control the start and stop of the water pumps 20 in the resulting control signal by processing the information in track temperature control device 30, the road surface temperature, snow melting road surface temperature T ₁ of example 4 ° C. at the time of snowfall To
In other conditions, the road surface preheating temperature T _2, for example, 2 ° C.
In addition, it is configured to control.

Conventionally, the temperature control of the snow melting road surface is performed according to a control flow shown in FIG. According to this control method, a signal for stopping the water supply pump 20 is output when the outside air temperature measured by the sensor is equal to or higher than a certain temperature. When the outside air temperature is equal to or lower than a certain temperature, and the measurement results of the snowfall sensor and the road surface moisture sensor are not snowfall and there is no road surface moisture (the absence of road surface moisture means that there is no freezing and there is no risk of freezing). In other words, the water pump 20 is set to the preheating operation mode. When the temperature measured by the road surface temperature sensor is higher than a set temperature during non-snowfall, for example, 2 ° C., the water pump 2
0 is stopped, and conversely, when the temperature is lower than the set temperature, the water pump 20 is set in the operating state, and the road surface temperature is set to this set temperature.

On the other hand, when it is determined that it is during snowfall or that there is moisture on the road surface, the water pump 20 is operated in the snow melting mode, and the road surface temperature is monitored by the road surface temperature sensor while the road surface temperature is set. The water pump 20 is operated until the temperature reaches, for example, 4 ° C.

As described above, in the above-described conventional method for controlling the road snow melting apparatus, the temperature of the hot water in the hot water storage tank is always controlled to a constant target value T _O irrespective of the presence or absence of snowfall. in the road heating system, preliminarily setting the snow melting road surface temperature during snowfall constant set temperatures T ₁ for example 4 ° C., the road surface preheating temperature during non-snow constant set temperature T ₂
For example, the water pump is set to 2 ° C., and the start / stop control of the water supply pump is performed so that the road surface temperature becomes the respective set temperature during snowfall or during non-snowfall.

[0009]

However, in this conventional apparatus and its control method, temperature control suitable for the surrounding environment of the installation location of this apparatus is not performed in the circulation system between the heat pump and the hot water storage tank. Irrespective of the amount of heat radiation from the road surface that changes in accordance with environmental changes (this is called road surface load or road surface heat load. The unit is kcal / m ² h (kilocalories / square meter / hour)). The temperature of the hot water is kept constant.

For this reason, according to the conventional apparatus and the control method, the heat pump heat source unit is always turned on / off so that the temperature of the hot water in the hot water tank is kept at a constant temperature T _0. Below, lowering the temperature of the hot water returned from the hot water tank increases the heating efficiency of the heat pump,
In addition, even when the heating capacity is increased, which is far more advantageous in terms of thermal efficiency, the heat pump is operated with inefficient high-temperature heating. In the case of a heat pump, the efficiency is significantly reduced if the operation is repeatedly started and stopped.
In the conventional control method, since an appropriate temperature range for controlling start and stop is not provided, excessive start and stop are repeated, thereby reducing the efficiency of the heat pump. Therefore, considering the running cost of the heat pump heat source unit, the control method of the conventional apparatus is very uneconomical.

SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems described above and to operate a heat pump heat source unit efficiently, and accordingly, an object of the present invention is to provide a heat pump heat source from a hot water storage tank. To set the return hot water temperature to the machine to the lower limit temperature level required by the road surface load, and to match the lower limit and upper limit of the return hot water temperature with the heating capacity of the heat pump and to maintain an appropriate operation continuation time A road surface snow melting device that can operate the heat pump heat source equipment efficiently and reduce running cact by increasing or decreasing the heating capacity of the heat pump heat source equipment according to the road surface load condition. Is to provide a control method.

[0012]

According to the present invention, there is provided a method for controlling a snow melting apparatus according to the present invention, which has the following features.

In this method, hot water heated by a heat pump heat source device is circulated to a hot water storage tank by a circulation pump, and a part of the hot water in the hot water storage tank is circulated by a water supply pump through a road surface pipe provided on a snow melting road surface. It controls the snow melting device on the road.

In this control, the hot water circulation system between the heat pump heat source unit and the hot water storage layer is controlled so as to operate the heat pump heat source unit efficiently. (A) When snow falls, the road surface in the snow melting mode according to the area heat radiation amount (hereinafter, this road heat radiation amount is referred to as a first road load Q _SN.) set, in a time of non snowfall, the outside air temperature T _a in the vicinity of the wind velocity V _a and snow melting road surface in the vicinity of the snow melting road surface The corresponding amount of road surface heat dissipation in the anti-freezing and preheating modes (hereinafter,
The road surface heat radiation amount is referred to as a second road load Q _V. ) Comprising the steps of: defining a (b) in response to the first road load Q _SN and second road load Q _V, respectively the lower limit T _L and the upper limit value T _H of the proper temperature range of the return hot water to the heat pump hot water storage tank (C) activating or stopping the heat pump heat source device or reducing the heating capability of the heat source device so that the current temperature T of the returned hot water in the hot water tank falls within an appropriate temperature range of the hot water. Increasing or decreasing.

According to the control method of the present invention, a current road surface heat dissipation Q (general term for road surface load) according to the surrounding environment of the area where the snow melting device is installed is first determined. The road surface heat release amount Q includes the first in the snow melting mode determined according to the area.
The second road load Q for the anti-freezing and preheating mode in consideration of the road load Q _SN and the wind speed and the outside air temperature in the area.
_If the first road surface load is registered in advance in the memory as a value determined for each region, the first road surface load can be read from the memory simply by setting the region.

On the other hand, since the second road load is given as a function of the wind speed and the outside air temperature, this equation is registered in an appropriate memory, and the measured wind speed and the outside air temperature (these wind speed and outside air temperature are , Preferably an average value within a certain period of time.).
Alternatively, the value calculated by this formula for each expected wind speed and outside air temperature is stored in advance in a table in an appropriate memory as the value of the second road surface load, and the value corresponding to the corresponding wind speed and outside air temperature is stored. The second road load may be read from the memory.

Furthermore, the return hot water in the hot water tank, wherein the experience to provide the first and second road load (Q _SN and Q _V) to the corresponding upper and lower limit temperature (lower limit value T _L and the upper limit value T _H) Is required by The equation that gives the lower limit is a function of the first or second road load (Q _SN or Q _V ), and the equation that gives the upper limit is the lower limit and the first or second
It is a function of the road load (Q _SN or Q _V ). The equations giving these upper and lower limits are registered in an appropriate memory, and the first
And each time the second road load (Q _SN and Q _V) is determined, it is possible to calculate the lower limit value T _L and the upper limit value T _H by using these formulas. Alternatively, the upper limit value and the lower limit value corresponding to the expected first and second road surface loads (Q _SN and Q _V ) are calculated in advance using these equations, and these values are stored in an appropriate table memory. Alternatively, it may be stored in another memory so as to be freely read. By doing so, the first and second road loads (Q _SN
And Q _V ), the lower and upper limits corresponding to these values can be read from the memory.

In this way, the current road surface load (Q
_SN or Q _V ) corresponding to the upper limit value _TH and the lower limit value T
The temperature range between _L can be obtained as an appropriate temperature range of the hot water in the hot water tank.

Next, the actual temperature (current temperature) T of the return hot water in the hot water tank at the present time is measured, and it is determined whether or not this temperature T is within the obtained appropriate temperature range. If the result of this determination is the measured temperature T is higher than the upper limit value T _H of the proper temperature range, to stop the heat source apparatus. As a result, the temperature of the hot water drops, and the temperature falls within an appropriate temperature range. On the other hand, as a result of the determination, when the measured temperature T is lower than the lower limit value _TL of the appropriate temperature range, the heat pump heat source device is started or its heating capability is increased to increase the hot water temperature to the appropriate temperature range. Starting, stopping, or increasing or decreasing the heating capacity of the heat source device can be performed by controlling the rotation of the heat source device.

As described above, according to the control method of the present invention, the temperature of the return hot water in the hot water tank can be brought within an appropriate temperature range according to the current surrounding environment, that is, the current road surface load condition. I can do it.

Further, in the embodiment of the present invention, preferably, before the step (b), the step of determining the heat source functional force Q _G of the heat pump heat source device as the heat source functional force according to the heat source temperature T _x is provided. Including. Then, in step of (b), it is good determined by using the lower limit value T _L and the heat source capabilities force Q _G upper limit value T _H described above. By doing so, it is possible to set upper and lower limits that are appropriate for the heat source function to be used. The heat source temperature is the outside air temperature when heat is taken from air, the water temperature when heat is taken from water, and the ground temperature when heat is taken from the ground.

Further, according to a preferred embodiment of the present invention, in steps of the above-described (ii), depending on the size of the first or second road load (Q _SN or Q _V), the upper limit T _H The heat pump heat source unit is fixed at the first limit temperature T _HH which can prevent excessive operation, and the lower limit value _TL is fixed at the second limit temperature T _LL for securing the rise time of snow melting of the road snow melting device within the allowable time. _{Alternatively} , the method may include a step of fixing the lower limit value _TL to a third limit temperature _TLH for avoiding unnecessary heating of the snow melting road surface. In this case, these first
Since each of the limit values 2 and 3 can be determined in advance according to the operating conditions of the road snow melting apparatus to which the present invention is applied and the heat pump heat source device to be used, these values are stored in advance in a memory in a freely readable manner. after the upper limit and the lower limit described above is determined, if the upper limit value T _H as compared with the first threshold temperature T _HH is the upper limit T _H ≧ first threshold temperature T _HH is the upper limit Forced first limit temperature T _HH
To When the lower limit value T _L is compared with the second and third limit temperatures (T _LL and T _LH ) and _TL ≦ T _LL , the lower limit value _TL is forcibly set to the second limit temperature T _LL. Set to. When T _L ≧ T _LH , the lower limit T
_L is forcibly set to the third limit temperature T _LH .

[0023] With this structure, or the upper limit value T _H obtained in accordance with the road load too much at a high temperature, or the lower limit value T _L is or too much cold, rather on the operation of the road surface snow-melting device It is possible to avoid an undesirable state (excessive operation of the heat pump heat source unit, delay of the start-up time of the device, or wasteful heating of the snow melting road surface).

In the embodiment of the present invention, the measured current temperature T of the returned hot water from the hot water storage tank is set to a lower limit value T _L.
If the temperature is lower than the above and the heat pump heat source device is stopped, it is preferable to start the heat source device and bring the heat source device into a low-speed heating state. Moreover, this case the current temperature T is high and the heat pump heat source apparatus than the upper limit T _H is in operation is suitably stopping the heat source apparatus. Also, if and heat pump heat source apparatus lower than the current temperature T is an upper limit value T _H is in operation, the first or second road load (Q _SN or Q _V) is a heat source function force Q _G and regions described above If the product is less than or equal to the product of the dependence coefficient f ₁ , the heat source unit is put into an efficient low-speed heating state, or the first or second road surface load (Q _SN or Q _V ) is equal to the heat source functional force Q _G and the local Dependency coefficient f
When it is larger than the product of ₁ , it is preferable to set the heat source device to a high-speed heating state in which the efficiency is reduced but the capacity is increased. With this configuration, the heat source unit returns the hot water to the hot water storage tank according to the operation or stop state of the heat pump heat source device and / or the comparison result between the measured return temperature T and the upper limit or the lower limit. The heating control can be performed in consideration of the operating state of the heat source device in addition to the ambient environment conditions, that is, finely.

In the embodiment of the present invention, preferably, the road surface temperature set value T _G for calculating the second road surface load is used.
Have set up, and compares the set value T _G and the outside air temperature T _a, when the outside air temperature T _a is the road set temperature T _G above, so that control of the road snow melting device is not malfunctioning In addition, it is preferable to set the above-mentioned second road load Q _V to Q _V = 0. With this configuration, when the second road surface load Q _V obtained from the actual measured wind speed and the outside air temperature becomes negative, the control is malfunctioned by forcibly setting this Q _V to zero (0). Can be prevented.

In carrying out the present invention, it is preferable to make the following settings.

First, the first road surface load Q _SN is set to 1 to 300 kc.
It is preferable that the value be within the range of al / m ² h.

When A and B are constants and coefficients determined depending on the roadbed structure, _Tg is a road surface setting temperature (° C.), and _Ta is an outside air temperature (° C.).
It is preferable that the second road surface load Q _{V is set} to Q _V = (A + B · V _a ) · (T _g −T _a ) kcal / m ² h.

When C and D are coefficients specific to the heat pump heat source unit and E is a constant specific to the heat source unit, the heat source functional force Q _G is Q _G = (C · T _x ² + D · (T _x + E) kcal / m ² h. In this case, when it is difficult to express the heat source functional force Q _G of the heat pump by the above equation, the heat source functional force Q _G corresponding to the heat source temperature T _x is obtained in advance, and the measured heat source temperature T _G is obtained. Heat source function Q corresponding to _x
G may be used.

Further, F is a heat transfer resistance R (m ² h ° C./kcal) between the snow melting road surface and the hot water, and a hot water flow rate I (l / m ² h).
Heat of antifreeze in road and road surface pipe C _f (kcal / ° C
l) When the first and second road loads (Q _SN and Q _V ) are represented by Q, the lower limit value _{TL is set} to _TL = (T _g + F · Q) ° C. Is preferred.

Further, the S _a and snow melting area (m ^2), G is the specific heat C _f (kcal / ℃ l) antifreeze in road pipe,
The coefficient depends on the volume W (l) of the hot water stored in the hot water tank and the operation continuation time H (h) of the heat pump heat source unit, and Q
_e is the surplus heat of the heat pump heat source unit (kcal / h), and the first and second road loads (Q _SN and Q _V )
When representing and represented by Q, it is preferable that the upper limit value _{T H T H = (T L} + G · Q e) ℃ and _{Q e = (Q G -Q)} · S a kcal / h.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

First, FIGS. 1A and 1B and FIG.
A basic description of the method for controlling the snow melting device of the present invention will be made with reference to FIGS.

[Basic Description] FIG. 1A is a basic conceptual diagram of a road snow melting apparatus to which the present invention is applied, and FIG. 1B is a control flow thereof.

The road surface snow melting apparatus to which the present invention is applied mainly includes a heat pump heat source device 10, a hot water storage tank 14, a circulation pipe 12 (upstream circulation pipe 12a and downstream circulation pipe 12b), and a circulation pump 18 provided in the same. And the water supply pipe 22 (upstream water supply pipe 22a, road surface pipe 22b
And downstream water pipe 22c (also referred to as a return pipe))
And a water pump 20 provided therein, and a temperature measuring device (also referred to as a temperature sensor) 24 for measuring the temperature of hot water in the hot water tank.
The hot water heated at 0 is supplied to the hot water storage tank 14 by the circulation pump 18.
And a part of the hot water 16 in the hot water storage tank 14 is circulated by a water supply pump 20 through a road surface pipe 22b provided on the snow melting road surface.

The road snow melting apparatus to which the present invention is applied includes a main sensor unit 50 for installing the snow melting apparatus or measuring the surrounding environmental conditions in the area where the snow melting apparatus is installed. Device (wind speed sensor) 5
2, a heat source temperature measuring device (heat source temperature sensor) 53, an outside air temperature measuring device (outside air temperature sensor) 54, and a snowfall measuring device (snowfall sensor) 56 are provided. Further, based on the measurement results of these devices 52, 53, 54, 56 and the temperature sensor 24, the heat pump heat source device 10 starts or stops the heat source device, or increases or decreases the heating capacity of the heat source device. For this purpose, a control signal generator 100 for generating a control signal is provided.

The control signal generating section 100 of the road snow melting apparatus having such a configuration is constituted by a microcomputer. Therefore, CPU (central processing unit), memory, input / output device,
Other necessary components are provided, and all or a part of them is determined in accordance with the design, snowfall determination means described later,
The road surface heat radiation amount determination unit, the upper and lower limit temperature determination unit, and the control signal generation circuit may be shared, or may be provided individually. Here, the memory in the CPU and the memory outside the CPU, if any, are collectively referred to as a memory unit. In this memory unit, information obtained in advance required for processing in the road snow melting device is stored in a readable and rewritable manner, or a keyboard or other suitable measuring means such as a sensor is used. A / D if necessary information from external input unit
The data can be read and rewritten freely via the converter, and the information and the like obtained in the control signal generator can also be read and rewritten freely. The processing related to the writing and reading of information to and from the memory unit is a well-known matter in a control device using a microcomputer, and thus a detailed description thereof will be omitted unless it is particularly necessary.

Furthermore, the road surface snow melting apparatus is provided with a timer 60, a keyboard or a numeric keypad, and other external input devices 70, and external information from these is sent to the control signal generator 100 via the A / D converter 82. It is configured to be able to input. The control signal generator 100 is configured to supply control signals to the heat source device 10 and the circulation pump 18 via the D / A converter 84, respectively. And
Naturally, these electric components described above are supplied with a predetermined power from a power supply (not shown), and are operated in a required synchronization with each other. Since the point configuration itself does not have the features of the present invention, the description thereof is omitted.

The basic operation of the road snow melting apparatus will be schematically described. Turn on the device. Main sensor 50
The wind speed sensor 52, the heat source temperature sensor 53, the outside air temperature sensor 54, and the snowfall sensor 56 operate to send information to the control signal generator 100. On the other hand, as in the conventional case, the sensor unit 28
The road surface temperature measuring device (road surface temperature sensor) 32 and the road surface moisture measuring device (moisture sensor) 34 also operate, so that the information from these sensors 32 and 34 together with the information from the outside air temperature sensor 54 and the snowfall sensor 56 It is sent to the control device 30 to control the water pump 20 as in the conventional case.

Next, when the input device 70 is operated to input the set area information of the road snow melting apparatus, the control signal generator 100 outputs the road surface heat radiation amount (in the snow melting mode) according to the designated area. Hereinafter, this road surface heat dissipation amount is referred to as a first road surface load Q.
_{Called SN} . ) Is set to a specific value (step 1 (hereinafter, steps are simply represented by S. Therefore, step 1 is S
1). Since the value of the first road surface load Q _SN is known in advance for each region based on experience,
If it is stored in the memory unit of the control signal generation unit 100, it can be read.

On the other hand, the wind velocity sensor 52 and the outside air temperature sensor 54, the information of the wind speed V _a and the outside air temperature T _a in the vicinity of the snow melting road surface in the vicinity of the snow melting road surface is inputted to the control signal generating section 100, these wind V _a (e.g. average wind speed for a predetermined time) and in accordance with the outside air temperature T _a (for example, average temperature for a period of time), the road surface the heat radiation amount when antifreeze and preheat mode (hereinafter, the road surface heat radiation amount second road load is referred to as a Q _V.) define the (S2). This second road load Q _V
Since being determined as a function of wind speed V _a and temperature T _a, the information a control signal generating section relating to the function formula 1
May be stored in the memory unit 00, when these information V _a and T _a has been input, it is possible to define a second road load by performing the necessary calculation it has been read out information related to this equation. Alternatively, obtained in advance of the second road load corresponding to various combinations of values of both information V _a and T _a, in advance to store them in the table (table) in the memory unit, the both information When input, it can be directly read from the memory unit.

Since the snowfall information has been input from the snowfall sensor 56 to the control signal generator 100, it is possible to determine the presence or absence of snowfall. As a result of this determination, the upper limit value _TH and the lower limit value _TL of the appropriate temperature range of the hot water in the hot water storage tank according to the first road surface load Q _SN during snowfall are determined. corresponding to _V, the return hot water (in this case, that returning hot hot water returning to the heat pump hot water storage tank) in the hot water storage tank defining an upper limit value T _H and the lower limit value T _L of the proper temperature range (S3). As described above, the first and second road loads (Q _SN and Q
Expression that provides an upper limit corresponding to _V) and the lower limit temperature (lower limit value T _L and the upper limit value T _H) has been demanded. Information on the equations giving the lower and upper limits is stored in the memory of the control signal generator 100, and the information is stored every time the first and second road loads (Q _SN and Q _V ) are determined. Read and perform calculations to obtain lower limit value T _L and upper limit value T
_H can be calculated. Alternatively, the upper limit value and the lower limit value corresponding to the expected first and second road loads (Q _SN and Q _V ) are calculated in advance using these equations, and these calculated values are read out to the memory unit. The information may be freely stored in a table. In this way, when the first and second road loads (Q _SN and Q _V ) are obtained, the lower limit value and the upper limit value corresponding to these values can be read from the memory unit.

Next, the current temperature T of the returned hot water in the hot water tank 14 is input to the control signal generator 100 by the temperature sensor 24. In order to keep the present temperature T within an appropriate temperature range according to the surrounding environment of the returned hot water, the above-described heat pump heat source device 10 is started or stopped, or the heating capability of the heat source device 10 is increased or decreased. (S
4). For this reason, it is determined whether or not the temperature T is within the obtained appropriate temperature range. If the result of this determination is the current temperature T is higher than the upper limit value T _H of the proper temperature range,
A control signal for stopping the heat source device 10 is sent from the control signal generator 100 to the heat source device 10. On the other hand, as a result of the determination, if the current temperature T is lower than the lower limit value _TL of the appropriate temperature range, the control signal generation unit 100 issues a control signal for starting the heat source unit or increasing the heating capacity of the heat source unit. To the machine 10. Then, the heat pump heat source device 10 is operated in such a direction as to bring the temperature T of the returned hot water into the appropriate temperature range by these control signals, and by repeating the above-described steps S1 to S4, the current temperature T is surely adjusted to the appropriate temperature range. Inside.

[Description of Specific Embodiment] FIG. 4 is a block diagram for explaining an example of the configuration of the control signal generator 100. FIG. 5 is an explanatory diagram for explaining the relationship between the road surface load required in the present invention and the appropriate temperature range according to the environment of the hot water returned from the hot water tank. FIG.
FIG. 9 to FIG. 9 are a series of control flows for explaining a specific embodiment of the present invention.

Description of Configuration Example of Control Signal Generation Unit To facilitate understanding of the present invention, first, a configuration example of the control signal generation unit 100 of the road snow melting apparatus will be described.

The control signal generator 100 is provided with a memory 11
0, a snowfall determining means 120, a road surface heat radiation amount determining unit 130, an upper and lower limit temperature determining unit 140, and a control signal generating circuit 150.

The memory unit 110 includes a control signal generation unit 100
A configuration in which information known in advance, information newly input from the outside, information obtained in internal processing, and other information necessary for processing executed inside can be rewritten and read freely as required. As described above, in addition to the memory of the CPU, the CPU
It may include a memory provided outside. As the memory, a RAM, a ROM, or any other memory according to the design can be used.

The information written in the memory unit 110 includes, for example, wind speed information, heat source temperature information, outside air temperature information, snowfall information, road surface temperature information, road surface temperature setting information, road surface moisture information, timer information from the timer 60, and timer information from the timer 60. Various kinds of designation information from the input device 70, hot water temperature information, information on equations necessary for obtaining the first and second road loads, or information on the first and second road loads themselves, and upper and lower limits are required. There is information on the formulas, information on the upper limit value and the lower limit value itself, first, second, and third limit temperature information, heat source functional force information, and other information.

The snowfall determination means 120 is a means for determining the presence or absence of snowfall based on a signal from the snowfall sensor 56.

The road surface heat radiation amount determining section 130 determines the first and second road surface load (first road surface load) Q _SN and the second road surface heat load (second road surface heat radiation amount) Q _V. Means 132 and 134, and a control malfunction preventing means 1 for preventing malfunction of the control of the road snow melting apparatus.
36. Since this first road surface load Q _SN is a road surface heat radiation amount in the snow melting mode according to the area at the time of snowfall,
It is known in advance which area is large and how large. Therefore, the value of the first road surface load Q _SN corresponding to the setting area of the road snow melting device is written in the memory unit 110. This Q _SN, roughly 1~300kca
If it is set within the range of 1 / m ² h, it is possible to cover almost the installation area. By the way, in the Sapporo area, the first road surface load Q _SN is about 230 kcal / m ² h
It is. Note that the above-described Q _SN and Q _V may be collectively simply referred to as road surface load Q.

The second road surface load Q _V is the amount of heat released from the road surface in the freeze prevention and preheating modes, and the average wind speed V _a near the snow melting road surface measured by the wind speed sensor 52 described above.
(M / s) and the average outside air temperature T _a (° C.) in the vicinity of the snow melting road surface measured by the above-described outside air temperature sensor 56, and is given by the following formula based on experience (for example, , Literature: Revised Group 11, Air Conditioning and Sanitary Engineering Handbook II Air Conditioning Equipment, edited by the Society of Air Conditioning and Sanitary Engineers, II-1
36, published in 1987).

[0052] _{Q V = (A + B ·} V a) · (T g -T a) kcal / m 2 h , however, a constant and coefficient determined depending A and B, respectively roadbed structure, T _g the road set temperature (° C).

Further, the control malfunction prevention means 136 of the road surface heat radiation amount determining unit 130 compares the road surface temperature set value _TG for calculating the second road surface load with the outdoor air temperature _Ta , and compares this outdoor air temperature T _a. when is it road set temperature T _G above, the second road load Q _V described above in Q _V = 0. This means 13
6, when the second road surface load Q _V obtained by the actual measured wind speed and the outside air temperature becomes negative,
By forcibly setting _V to zero (0), it is possible to prevent malfunction of the control of the road snow melting apparatus.

The upper and lower limit temperature determining unit 140 determines the upper limit value _TH and the lower limit value _TL of the appropriate temperature range of the returned hot water in the hot water storage tank 14 according to the result of the determination made by the snowfall determining means 120 described above.
Are respectively determined based on the upper and lower limit value information written in the memory unit 110 described above. This determination unit 140
Are the heat source functional force output means 141 and the upper and lower limit value output means 1
43, size comparison means 145 and limit temperature fixing means 14
7 and the limit temperature fixing means 147 has the first
Temperature comparing means 149 is provided.

The heat source function force output means 141, in addition to the surrounding environment, taking into account also the capacity Q _G of the heat pump heat source apparatus 10 to be used, with means provided to control the temperature of the return hot water of the hot water storage tank 14 is there. The capacity of the heat pump type heat source unit is output as Q _G (kcal / m ² h). in this case,
Preferably, it had better be a heat source capability to be dependent on the heat source temperature T _x adopts a heat source function force Q _G. For example, as the heat source function force Q _G, that gives the following equation, which is theoretically calculated by experience are preferred.

Q _G = (C · T _x ² + D · T _x + E) kcal / m ² h where C and D are coefficients specific to the heat source unit, and E is a constant constant specific to the heat source unit. .

[0057] In this case, the heat pump having a difficult characteristic to be expressed as a function of the heat source temperature T _x adopts the Q _GH, which is previously obtained values of the heat source function force to adopt the heat source temperature T _x a memory unit may be stored in the heat source function force corresponding to the measured adopted heat source temperature T _x may be to give from the memory unit.

[0058] upper and lower limit value outputting means 143 outputs the lower limit T _L which depends on the road surface temperature setting value T _G and the road surface load Q (Q _SN or Q _V), the lower limit T _L and a heat pump heat source function outputting a force Q _G (Q _GH or Q _GB) and the upper limit value T _H which is largely dependent on. This road surface temperature set value T _G
Is a value to be set in order to calculate the road surface heat radiation amount Q _V can be set as a value corresponding to the environment to this value may be previously stored in the memory unit 110 reads out freely, or from the outside You may enter it.

The lower limit value T _L and the upper limit value T _H are theoretically obtained based on experience, for example, by the following equations, respectively. Therefore, it is preferable to set the lower limit and the upper limit obtained according to these equations. is there.

T _L = (T _g + F · Q) ° C. Here, F is the heat transfer resistance R (m ² h ° C. /
kcal), the hot water flow rate I (l / m ² h) and the specific heat C _f (kcal / ° C. 1) of the antifreeze in the road surface pipe.

[0061] _{T H = (T L + G} · Q e) ℃ Q e = (Q G -Q) · S a kcal / h , however, the S _a and snow melting area (m ^2). G is a coefficient that depends on the specific heat C _f (kcal / ° C. 1) of the antifreeze in the road surface pipe, the volume W (l) of the hot water stored in the hot water tank, and the operation continuation time H (h) of the heat pump heat source unit. Let Q _{e be} the surplus heat (kcal / h) of the heat pump heat source unit.

The magnitude comparing means 145 is means for comparing the magnitude of the heat pump heat source functional force Q _G with the road surface load Q. The reason for this comparison is that the heat source functional force Q _G is smaller than the road surface load Q. In such a case, the control of the snow melting device on the road surface may be in an erroneous operation state. The result of this comparison is sent to limit temperature fixing means 147.

The limit value temperature fixing means 147 determines the upper limit value _TH and the lower limit value _TL based on the comparison result from the magnitude comparing means 145 and based on the limit temperature information written in the memory unit 110. When the temperature is outside the appropriate temperature range, the upper limit value _TH and the lower limit value _TL are restricted. These limitations, or the upper limit value T _H is fixed to the first threshold temperature T _HH capable of preventing an excessive operation of the heat pump heat source apparatus 10, also, the lower limit T _L to within the allowed time the rise time of melting snow road snow melting apparatus and to or fixed to the third threshold temperature T _LH to avoid unnecessary heating to the second threshold temperature T or melting snow road lower limit T _{L LL} to fix to ensure the.

In this case, the limit temperature fixing means 147 compares the level of the upper limit value _TH with the level of the first limit temperature _THH ,
It is preferable to include first temperature comparing means for comparing the level between the lower limit value T _L and the second and third limit temperature values (T _LL and T _LH ).

Since the information ( _THH , _TLL, and _TLH ) of each of the first, second, and third limit temperatures can be set in advance by the type of the snow melting apparatus for the road surface and the type of heat pump heat source equipment used for the apparatus. The information is stored in the memory unit 110 in a readable manner in advance. Then, after comparing the magnitude of the heat pump heat source functional force Q _G with the road surface load Q by the magnitude comparison means 145, the limit temperature fixing means 147
The memory unit 110 is accessed, and the limit temperature information (T _HH , T _LL, and T _LH ) is read therefrom. In the first temperature comparison means 149 of the limit temperature fixing means 147, the upper and lower limit value information (T _L and T _H ) from the upper and lower limit value output means 143 and the limit temperature information (T _HH , T _H ) read from the memory unit 110 _LL and T _LH ). When the upper limit value T _H is higher than the corresponding limit temperature T _HH fixes the upper limit to the limit temperature T _HH. In addition, the lower limit value T _L
Is lower than the corresponding limit temperature T _{LL and} higher than T _LH , respectively, this lower limit is fixed to the limit temperatures T _LL and T _LH , respectively. If with such configuration, as previously described, or too much road load Q (Q _SN or Q _V) upper limit T _H obtained in accordance with the high temperature, or the lower limit value T _L is a low temperature To prevent the snow melting device from being in an unfavorable state for its operation (excessive operation of the heat pump heat source device, delay in the rise time of the device or wasteful heating of the snow melting road surface) due to being too much. Can be done.

Next, the control signal generating circuit 150 includes a second temperature comparing means 152 and a control signal generating means 154. In the second temperature comparison means 152 of the circuit 150,
The current temperature T of the returning hot water in the hot water storage tank 14 measured by the hot water temperature measuring device (hot water sensor) 24 is determined by the above-mentioned upper and lower limit temperature determining unit 140, and the appropriate temperature range (T _{L) of the} hot water 16 is determined. <T <T _H ) to compare the temperatures. The result is sent to the control signal generating means 154, and according to the result of the above-mentioned temperature comparison, in order to bring the temperature of the returned hot water into the above-mentioned appropriate temperature range or to maintain it in that temperature range. Is sent to the heat pump heat source machine 10 and its driving unit (not shown). If in this manner, it measured when the current temperature T of the return hot water of the hot water tank 14 is higher than the upper limit value T _H is stopped or heating capacity heat pump heat source apparatus 10 to lower the temperature of hot water Can be output from the control signal generation means 154 to the heat pump heat source device 10.

On the other hand, if the current return hot water temperature T is lower than the lower limit value T _L
If it is lower than this, it is possible to output a control signal to the heat pump heat source device 10 to increase the temperature of the hot water or to increase the temperature of the hot water.
Therefore, the measured current temperature T of the returned hot water in the hot water tank 14
Is too high or too low, automatically controlling to bring the current temperature T within the appropriate temperature range defined by the surrounding environmental conditions, or to maintain the temperature T within the appropriate temperature range. Can be done.

Next, an embodiment of a control method of the snow melting apparatus according to the present invention will be described with reference to FIGS. 6 to 9. Control signal generator 10
It is assumed that necessary information known before the operation of the apparatus is written in the memory unit 110 of 0. As such information, for example, the first road surface load Q _SN (variable constant: for example, 1
３００300 kcal / m ² h), necessary information for calculating the second road load Q _V , the road surface setting temperature T _g (variable constant: for example, 2 ° C.), and the heat pump heat source functional force Q _G required for calculation Upper limit value T _H , lower limit value T
Information on the equations required to calculate _L and excess heat _Qe , respectively, first, second and third temperature limit values _THH , TH
_LL and T _LH (variable constants: for example, T _HH , T _LL and T
_{LH is} 0 to 50 ° C.), and the heat transfer resistance R between the road surface and the hot water in the road surface pipe (for example, 0.1367 m ² h ° C./kc)
al), operation continuation time H (variable constant: for example, 0 to 5.0)
Time), specific heat of antifreeze C _f (for example, 0.5 to 1.0 kc
al / ° C.), a variable coefficient f ₁ (for example, 0
2.00), snow melting area S _a (e.g., 1 to 500
² ) There are required coefficients, constants and other information.

In this embodiment, an example will be described in which the heat collection source is air and the heat collection source sensor 53 and the outside air temperature sensor 54 are shared (accordingly, T _a = T _x ). It is also assumed that a snow melting device will be installed in the Sapporo area. Therefore, the first road load Q _SN is set to 230 kcal / m ² h. The second road surface load Q _V is calculated by the equation Q _V = (A + B · V _a ) described above.
The second road load determining means 13 according to (T _g -T _a )
And the lower limit value _{TL of the} appropriate temperature range.
Is the excess heat Q _e according to the equation T _L = (T _g + F · Q).
The formula _{Q e = (Q G -Q)} · S according _a, and the upper limit value T _H of the proper temperature range, wherein _{T H = (T L + G} · Q e)
Are calculated by the upper and lower limit output means 143 in accordance with
In this embodiment, for example, T _{g is set} to 2 ° C., T _{HH is set} to 37 ° C., T _{LH is set} to 30 ° C., and T _LL is set to 20 ° C.

When the power supply (not shown) of the road snow melting apparatus is turned on, the control of the present invention starts (starts), and this control is continuously performed until the power supply is turned off. When the control operation starts, the wind speed information V
_a , the outside air temperature information T _a from the outside air temperature sensor 54, the snowfall information from the snow fall sensor 56, and the information T on the return hot water temperature in the hot water storage tank 14 from the temperature sensor 24 are passed through the A / D converter 82 to the control signal generator 100. (S10). These pieces of information are written in the memory unit 110 in a rewritable state at predetermined time intervals as necessary.

From the external input device 70, for example, area designation, that is, Sapporo area designation information, hot water flow rate I (for example, 20
1 / m ² h), hot water tank capacity W (for example, 8000 l),
Snow melting area S _a (for example, 360 m ² ), road surface setting temperature T
Enter the information specified in _g, the information specifying that the heat source unit is a heat pump type, and other necessary information. The area designation signal is input to the first road load determining means 132 of the control signal generator 100. When the designation signal is input, the information (230 kcal / m ² ) of the specific first road surface load Q _SN corresponding to the designation signal is input from the memory unit 110.
h), and sends the read information to the upper and lower temperature limiter 140 (S12).

On the other hand, the second road surface load determining means 134
When the specified information of the information of the outside air temperature T _a and the road set temperature T _g is incoming, the memory unit _{110 Q V = (A + B} ·
The information of (V _a ) · (T _g -T _a ) is read out, the operation of this formula is performed, the second road surface load information Q _V is calculated, and the result Q _V is output, and once required, as needed. It is stored in the memory unit 110 (S14). In this embodiment,
For example, if f ₁ = 1, A = 13.25 and B =
3.4.

The heat source function output means 141 of the upper and lower limit temperature determining unit 140 outputs the heat source unit designation information and the outside air temperature _Ta.
Is read out from the memory unit 110. And by specifying the heat source unit 10 is a heat pump, a heat source function force Q _G from the memory unit 110 to calculate a Q _GH formula ^{_{(Q G = CT a 2 +}} DT a +
E) is read, operation is performed with calculating and outputting a heat source function force Q _G, once the memory unit 1 in accordance with the required
10 (S16). In this embodiment, C =
-1.61, D = -1.93, and E = 244.44.
And

Next, the information of the outside air temperature T _a measured and read information of the road set temperature T _g when determining the second road load Q _V is input to the control malfunction prevention means 136, the means in 136, it compares the level of both temperatures T _g and T _a (S18). Results of the temperature comparison, when the outside air temperature T _a is less than the road set temperature The T _g, the process proceeds to step of the presence or absence of the next snowfall (S20). However, _Ta
Is equal to or higher than T _g , the second
The road surface load Q _V becomes Q _V <0, and as a result, the control of the road surface snow melting apparatus performed here malfunctions. To prevent this, Q _V = 0 is forcibly set (S20).

Next, from the snow sensor 56, measurement information indicating whether snow is falling or not is determined by the snow determination means 1 of the control signal generator 100.
20, the snowfall determination means 120
At the time, it is determined whether it is snowfall based on the measurement information,
The result of the determination is output (S22). If it is determined that it is snowfall, a command to turn on the snowfall delay timer 60 is sent from the snowfall determination means 120 to the timer 60 via the D / A converter 84, and after the heat source device 10 and the circulation pump 18 are stopped, After a predetermined time t has elapsed, the timer 60 is set so as to stop the water pump (S24).
On the other hand, if it is determined that no snowfall has occurred, it is determined whether the timer 60 has timed out (S26).

After step (S24) and after step (S
If it is determined in 26) that the time has not elapsed (the stop delay time t of the water supply pump set by the timer has not elapsed), these pieces of information are stored in the upper and lower temperature limiter 1.
40 is sent to the upper / lower limit output means 143. The upper / lower limit output means 143 outputs the road load Q to the first road load Q _SN
Is set in the memory unit 110 as necessary (S28 in FIG. 7). Also, if time-up has occurred (has passed a stop delay time t of the water pump set by the timer.) Is that in S26, since no snow, sets the road load Q to the second road load Q _V (S30 in FIG. 7). It is to be noted that such a timer 60 may be appropriately provided according to the design. By providing this timer 60, the number of times of turning on / off the heat source device itself can be reduced, or the heat source device can be turned off in the case of snow melting due to remaining snow. If it is delayed or if snow falls, the heat source can be operated for at least about 10 minutes after the heat source is activated. When the timer 60 is not provided, Q may be designated as Q _SN during snowfall and Q may be designated as Q _V during non-snow.

The first or the second determined in this way
Based on the information on the road load (Q _SN or Q _V ), the upper and lower limit output means 143 outputs the upper limit _TH and the lower limit _TL.
Is required. Here, an example will be described assuming that the first road surface load _QSN is set. First, the road surface set temperature T
_{When g} is input and the information of the first road surface load Q _SN is specified, the equation _TL = T for obtaining the lower limit value _TL from the memory unit 110 is obtained.
The information of _g + F · Q is read, and Q is set to Q _SN , and the operation of this expression is performed to obtain T _L = T _g + F · Q _SN (S3
2). Next, the equation Q _e = (Q _G −Q) · S _a for calculating the surplus heat Q _e is read from the memory unit 110, and the heat source functional force Q _G = Q _GH already determined and the first road surface load are obtained. Q _SN
By using the information of the Q seeking Q the _SN and Q _G performed to operation on Q _GH excess heat _{Q e = (Q GH -Q SN} ) · S a, in accordance with this required memory Stored in the section 110 (S
34). Next, here performs an operation by reading the information about the expression by accessing the memory unit 110 obtains the upper limit by the information of Motoma' lower limit T _L and excess heat Q _e, the upper limit value _{T H = T L + G ·} Q _{e = T g + F · Q} SN + G ((Q
_GH− Q _SN ) · S _a ) = T _g + (FG−S _a ) Q _SN + G
· S _a · Q _GH is determined (S36). And stores the upper limit value T _H in the memory unit 110 if desired. In this embodiment, for example, F = 0.161 and G = 1/8000
And

Here, referring to FIG. 5, the road surface heat load, that is, the first and second road surface loads (represented by Q).
The relationship between (kcal / m ² h) and the set temperature (° C.) of the return hot water in the hot water storage tank 14 will be described. In FIG. 5, the road surface heat load Q is plotted on the horizontal axis, and the temperature is plotted on the vertical axis. Since the lower limit value T _L is a linear function of Q, its possible values are, for example, on a straight line _TL consisting of a solid line portion and a dotted line portion on both sides thereof, and T _g and F are constant values. Therefore, once the road load Q is determined, it is uniquely determined. On the other hand, T _g , F, G, and _Sa are constant values, and the heat source functional force is a constant value if the type of the heat pump heat source device 10 is determined.
_{H is} also a linear function of the road load Q. Thus, for example, the value of the upper limit value T _H is linearly T consisting of a solid line and the broken line portion
_It is on the line _H and is uniquely determined if the road surface load Q is determined. For example, the lower limit value T _L is such that the second road surface load Q _SN is 10
For 0,140,200,240, respectively,
It takes the value of _{T L1, T L2, T L3} , T L4. In addition, the upper limit value T _H
Respectively indicate T _H1 and T _{H with} respect to the value of the second road load.
Take the values of _H2 , _TH3 , _TH4 .

Next, both information of the heat source functional force Q _G and the road surface load Q (here, Q _SN ) are sent to the magnitude comparing means 145, where the magnitudes of both are compared (S38 in FIG. 8). As a result of this comparison, when Q _G ≧ Q, it means that the heat source functional force Q _G is large and the heat source device 10 is operating in the direction of increasing the heating temperature at the present time. It is sent to the limit temperature fixing means 147.

[0080] Then, the first temperature comparing means 149 of the means 147, and the upper limit value T _H stored in the memory unit 110 previously sought, in the hot water storage tank 14 that have been previously stored in the memory unit 110 First limit temperature T of returned hot water
_HH is read, and the magnitudes of the two are compared (S40 in FIG. 8). As a result of this comparison, when T _H ≧ T _HH , as shown in FIG. 5, for example, the first road surface load Q _SN is 20
In the case of 0 or 240 (kcal / m ² h),
In response to each of the temperature T _H of the return hot water T _H3 (about 3
8 ° C) or _TH4 (about 40 ° C) or the first limit temperature T
Since the temperature becomes higher than _HH = 37 ° C., these values _TH3 or _TH4 are forcibly set to _THH in the limit value fixing means 147 (downward in the direction indicated by the arrow in FIG. 5) (S42). ).

After step S42, when it is determined that T _H <T _HH , or as a result of the comparison in step S38, it is determined that Q _G <Q (here, the first road load Q _SN ). when (which means that a malfunction in the control does not occur.), the processing proceeds to a comparison step to the next lower value T _L and a second limit temperature T _LL (S44). As an example of the case where T _H <T _HH , FIG. 5 shows that Q _SN is 100 or 140, for example.
(Kcal / m ² h) at a temperature T _H1 (about 32.5
° C) or _TH2 (about 35 ° C).

The first temperature comparing means 149 performs the processing of step S44. Therefore, the information of the lower limit value T _L that has been obtained and stored in the memory unit 110,
Performing a comparison of both temperature came reads in advance or may be stored in the memory unit 110 of the hot water storage tank 14 of the return hot water of the second limit temperature T _LL information (S44). As a result of this comparison,
For example, when Q is 100 (kcal / m ² h), T
If it is determined that _L ≦ T _LL , the lower limit value _TL is lower than the second limit temperature T _LL = 20 ° C., for example, T _{L1 in} FIG.
(Approximately 18 ° C.), the rise time of snow melting of the snow melting apparatus may be long. Therefore, in order to keep the rise time within the allowable time arbitrarily determined according to the design, the limit value temperature fixing means 147 forcibly sets the limit value T _L to the second value.
The temperature is raised and fixed to the limit temperature _TLL (the temperature is raised in the direction indicated by the arrow in FIG. 5) (S46).

On the other hand, when Q (here, the first road load Q _SN ) is 140, ²⁰⁰ and 240 (kcal / m ² h), the lower limit values T _L are T _L2 (about 24.5 ° C.) and T _{L3, respectively.}
Since (about 34 ° C.) and T _L4 (about 41 ℃), T _L
> _TLL, and at this time, the lower limit value _TL may be set to the temperature already determined.

If the lower limit value T _L is too high, the heat pump heat source device 10 wastefully heats the snow melting on the road surface. Therefore, it is necessary to avoid such unnecessary heating in advance. Accordingly, in a first temperature comparing means 149 limits the temperature fixing means 147 compares the lower limit value T _L and the third threshold temperature T _LH (S48). Since this embodiment, it is registered in advance the T _LH as 30 ° C. in the memory unit 110, T _LH from the memory unit 110
And T _L are read and this comparison is made. In FIG. 5, the first road surface load Q _SN is 200 or 240 (kcal
/ M ² h), the corresponding temperature is T _L3 (about 3
4 ° C.) and T _L4 (about 41 ° C.), T _L ≧ T _LH
Therefore, the limit temperature fixing means 1
At 47, the lower limit value T _{L is set} to the third limit temperature T _LH (30
° C) (pull down in the direction indicated by the arrow in Fig. 5) (S50). If it is determined in this comparison that T _L <T _LH , it means that the temperature is not high and T _LL or T _L = T _L2 already determined in the previous step (for example, S46). The process may proceed to the next step (S52).

As described above, steps S36 to S4
The processing by the limit temperature fixing means 147 up to 6 is summarized for each exemplified value of the road surface load Q as follows.

[0086] road load ^{(kcal / m 2 h):} 100 140 200 240 lower limit _{T L (℃): T LL} T L2 T LH T LH maximum value _{T H (℃): T H1} T H2 T HH T HH above Assuming that the above processing is performed for all the continuous road surface loads Q from 80 to 260 (kcal / m ² h),
The suitable temperature range of the hot water obtained in this example is indicated by a broken line I (upper limit) shown by a solid line and a broken line II shown by a solid line in FIG.
(Lower limit). For example, the polygonal line I is Q
A ^{= 180 (kcal / m 2 h} ) to linearly T _H, upward from this value consists a straight line fixed to the first threshold temperature T _HH. In addition, the polygonal line II has Q = 110 (kca
1 / m ² h), a straight line fixed at the second limit temperature T _LL , a straight line _TL up to Q = 110 to 170 (kcal / m ² h), and an upper third limit temperature T _L from this value. _It consists of a straight line fixed to _LH .

It should be noted that the above-mentioned broken lines I and II of the lower limit value and the upper limit value shown in FIG. 5 are merely examples, and are actually broken lines or straight lines of various shapes other than those shown in FIG. .

Next, control of the current temperature T of the returned hot water in the hot water storage tank 14 will be described.

Up to the above-described step S50, an appropriate temperature range to be controlled as the temperature of the return hot water in the hot water tank is determined for the value of the road surface load Q. Then, the second temperature comparison means 152 of the control signal generation circuit 150 compares the measured current hot water temperature T with the determined upper and lower limit values _TH and _TL . In this embodiment, Q = Q _SN = 230 (kcal / m ² h), where T is T ₁ = 45 ° C., T ₂ = 32 ° C., and T ₃
= 25 ° C. FIG. 5 plots these temperature points.

[0090] First, have read the lower limit T _L from the memory unit 110, and compares with the lower limit T _L and the measurement temperature T (S52). In this embodiment, when the value of Q is used, T _L is the second limit temperature T _LH (30 ° C.).
₃ < _TLH . Therefore, in this case, the hot water temperature T ₃
Is lower than the lower limit value T _LH of the appropriate temperature range, it is checked in the next step S54 whether the heat pump heat source device 10 is operating. (Not shown), a start signal is sent (S56), and a control signal for driving the heat source device 10 at a low speed or a low combustion state is sent from the control signal generating means 154 to the drive unit (S58). After this step S58, the and in step S54, when the heat source apparatus 10 is determined to be in operation proceeds to the comparison of the next upper limit value T _H.

When the current temperature T is T ₁ (45 ° C.) and T ₂ (32 ° C.), T _L = T _LH (30
Since ° C.) than is the high temperature, the process proceeds to compare the next upper limit value T _H after the determination of the step S52.

Before the comparison with the upper limit value, the information of the heat pump heat source functional power Q _G is read out from the memory unit 110 by the magnitude comparing means 145, and Q _G is again reproduced here.
And the road surface load Q (here, Q _SN ) is compared (S6).
0).

As a result of this comparison, if the heat pump heat source functional force Q _G is larger than the road surface load Q, there is no risk of malfunction of the control, and therefore, the comparison between the current temperature T and the first limit temperature _TH is performed. Is performed (S62). In this embodiment, the upper limit value T _H is T _HH (37 ℃). Therefore, the measurement temperature T
There _{T ≧ T H (= T HH} ) and become of, T is T ₁ (45 ℃)
Is the case. Therefore, when the measured temperature is T _1, since the heat pump heat source device 10 becomes excessive operation, when the heat source apparatus 10 is determined to during operation (S64), the heat source unit from the control signal generating means 154 10 Is output to the drive unit of the heat source device 10 (S66). S
After step 66, and when it is determined in step S64 that the heat source device 10 is stopped, it is determined whether this control is repeatedly performed or terminated (S76). Returning to S10, if not repeated, this control ends.

On the other hand, if the measured temperature T is T ₂ (32 ° C.) or T ₃ (25 ° C.), T <T _H (= _{TH HH} ) and the hot water temperature T is low. There is no risk of over-operation. However, since the case of T = T ₃ has already been determined in step S52, the case of T = T ₂ is determined in step S62. Therefore, in this case, T ₂ is T _LH <T ₂ <T _HH
Is satisfied, the hot water temperature T is within an appropriate temperature range, and the temperature may be maintained as it is. Therefore, it is next determined whether or not the heat pump heat source device 10 is operating (S68), and if not, step S7.
After that, the process returns to the first step S10, or this control ends. If it is determined in step S68 that the operation is being performed, the operation state of the heat source device 10 is checked again. In this case, in step S70 in the magnitude comparing means 145, the road surface load Q (the first
The road surface load Q _SN ) is compared with the quantity Q _G · f ₁ obtained by multiplying the heat source functional capacity by the local coefficient f ₁ . This f ₁ is the heat source functional power Q
_{Since G} is given by an approximate expression based on experience, fine adjustment is required depending on the installation area of the road snow melting apparatus, and therefore it is introduced only in this determination step S70.

As a result of the determination in step S70, Q ≦
If Q _G · f ₁ , it means that the heating capacity of the heat pump heat source unit is larger than the road surface load, that is, the amount of heat consumed on the snow melting road surface. If the continuous operation is performed, the temperature of the hot water may increase, resulting in a dangerous or wasteful heating state. Therefore, in this case, the comparison result is sent to the control signal generation circuit 154 of the control signal generation unit 150, and a control signal for reducing the rotation speed of the heat source device is output to the drive unit of the heat source device 10 therefrom ( S74).

As a result of the determination in step S70, Q>
In the case of Q _G · f ₁ , the heating capacity of the heat source unit is smaller than the road surface load. Therefore, if the operation state of the heat source unit 10 is continued as it is, the temperature of the hot water decreases, and the snow melting is impeded. May come. Therefore, in this case, the comparison result is output to the control signal generation circuit 15 of the control signal generation unit 150.
4, and outputs a control signal to the driving unit of the heat source device 10 to increase the rotation speed of the heat source device (S72).
After such steps S72 and S74, the process returns to the first step S10.

If it is determined in step S60 that Q _G <Q, the temperature of the hot water does not increase, so that the procedure may be continued with step S68 already described.

Note that, as described above, the first step S10
Since the surrounding environment changes every moment, various values obtained by measuring the ambient conditions also change. Accordingly, the second road surface load Q _V and the upper limit value and the lower limit value ( _TH and _TL ) of the appropriate temperature range among the road surface load Q also change, and the control of the road snow melting apparatus follows this change. It is to make it.

It is clear that the invention is not limited to the embodiments described above, but that many changes can be made. For example, in the above-described embodiments, numerical conditions have been described. However, these numerical conditions are merely preferable examples, and the objects and effects of the present invention can be achieved even with values other than these values. Alternatively, the numerical conditions may be determined according to the environment. Further, in the above-described embodiment, the example in which the road surface load Q is set to the first road surface load Q _SN has been described. However, even when the road surface load Q is set to the second road surface load Q _V , the lower limit value _{TL is set.} , the value of excess heat Q _e and the upper limit T _H varies, the control flow itself is the same as that of Q _SN, description of the control flow in the case where the road surface load Q was set to the second road load Q _V Is omitted.

Further, in the above-described embodiment, the second road surface load Q _V , the heat source functional force Q _G , the upper limit value _TH and the lower limit value _TL.
Has been described in an example in which information relating to these calculation formulas is stored in the memory unit, and these values are obtained by calculation using information obtained from outside. However, the second road surface load Q _{V is used for} each information obtained from outside. , The heat pump heat source function Q _G , the upper limit value _TH, and the lower limit value _TL are calculated in advance, and the calculated values are stored in a table in the memory unit in association with external information. Is also good. With this configuration, it is possible to immediately read the corresponding data, that is, the value from the memory unit in response to the external wind speed and temperature information without performing the calculation for obtaining these values after the input of the external information. Also, the configuration of the control device itself is simplified.

In the above-described embodiment, an example of the processing flow has been described. However, the processing order does not necessarily have to be the same as the order shown in FIGS. 6 to 9 and may be arbitrarily and appropriately changed according to the design. May be.

[0102] Further, in the above embodiment has been explained an example of sharing the adoption heat source temperature sensor and the external temperature sensor, provided both individually, by measuring the T _a and T _x Q
Control may be performed by obtaining _V and Q _G.

Although the hot water tank 14 has not been particularly described, in the embodiment of the present invention, the hot water tank has a structure in which the inside of the hot water tank is divided into three chambers sequentially communicating with each other. ing. The hot water tank having this structure is a hot water tank having a structure proposed by the present applicant in an application on the same date as the present application. In the present invention, the control method is substantially the same between the case of using the hot water storage tank and the case of using the conventional one-chamber structure hot water storage tank, so that the description of the hot water storage tank itself is omitted.

[0104]

As is apparent from the above description, according to the method for controlling the snow melting apparatus of the present invention, the road load is determined by the surrounding environmental conditions such as the wind speed, the temperature of the heat source, the outside air temperature, and the presence or absence of snowfall. The hot water temperature of the hot water tank corresponding to the road surface load, and when the temperature of the returned hot water is outside the appropriate temperature range, the heat source is set so as to bring the returned hot water temperature within the appropriate temperature range. Controlling the machine. Therefore, according to the present invention, the road surface (heat) load is constantly monitored in accordance with changes in the surrounding environment such as the heat source temperature, the outside air temperature, the wind speed, and the snowfall state, and the load in the hot water storage tank in accordance with the road surface load is monitored. Return hot water temperature is variably controlled. As described above, since the operation state of the road snow melting device can be controlled, the heat pump heat source device can be appropriately operated so as to supply the heat required by the snow melting road surface.

Further, in the present invention, since the heat pump heat source unit is controlled by setting the lower limit value and the upper limit value of the appropriate temperature range of the hot water storage tank, it is possible to operate with the minimum low-temperature heating required by the road surface. The operation of the heat pump can be continued by setting the temperature range of the lower limit value and the upper limit value in the hot water storage tank. Therefore, the operation efficiency of the heat pump is improved.

Further, since the heat pump heat source device is operated at a high speed or a low speed according to the road load, the heat pump heat source device can be operated under the most efficient conditions. Therefore, according to the present invention, there is an economical advantage that the running cost of the road snow melting apparatus can be reduced as compared with the conventional control method.

[Brief description of the drawings]

FIG. 1A is a configuration conceptual diagram for explaining a basic configuration example of a device itself to which a control method of a road snow melting apparatus of the present invention is applied, and FIG. 1B is a conceptual diagram of the control method of the present invention; It is a figure of a basic control flow.

FIG. 2 is a schematic configuration diagram for explaining a conventional road snow melting apparatus and a control method thereof.

FIGS. 3A and 3B are control flowcharts for explaining a control method in the conventional device having the configuration of FIG. 2;

FIG. 4 is a configuration diagram of a control signal generator for explaining the control signal generator for implementing the method of the present invention.

FIG. 5 is a diagram illustrating an example of setting a hot water temperature in a hot water tank for describing a control method according to the present invention.

FIG. 6 is a control flowchart of the embodiment of the present invention.

FIG. 7 is a control flowchart of the embodiment of the present invention, which is subsequent to FIG. 6;

FIG. 8 is a control flowchart of the embodiment of the present invention, continued from FIG. 7;

FIG. 9 is a control flowchart of the embodiment of the present invention, which is subsequent to FIG. 8;

[Explanation of symbols]

 10: heat pump heat source unit 12a: upstream reflux pipe 12b: downstream reflux pipe 14: hot water storage tank 16: hot water 18: reflux pump 20: water feed pump 22a: upstream water feed pipe 22b: road surface pipe 22c: downstream water feed pipe 24: hot water temperature measuring device 28: sensor unit 30: road surface temperature control device 50: main sensor unit 52: wind speed measurement device 53: heat source temperature measurement device 54: outside air temperature measurement device 56: snowfall measurement device 60: timer 70: input device 82: A / D Converter 84: D / A converter 100: Control signal generation unit 110: Memory unit 120: Snowfall determination unit 130: Road surface heat release amount determination unit 132: First road surface load determination unit 134: Second road surface load determination unit 136: Control Malfunction prevention means 140: Upper / lower limit temperature determining unit 141: Heat source functional force output means 143: Upper / lower limit value output means 1 5: size comparison means 147: limit temperature fixing means 149: first temperature comparing means 150: control signal generating circuit 152: second temperature comparing means 154: control signal generating means

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiji Nagata 5-373 Kita 4-Jo Higashi, Chuo-ku, Sapporo, Hokkaido Hokkaido Gas Co., Ltd. (72) Masaki Mikami 5 Kita 4-Jo East, Chuo-ku, Sapporo, Hokkaido No. 373, Hokkaido Gas Co., Ltd. (72) Inventor Hajime Onoda 1-2-3, Shimura, Itabashi-ku, Tokyo, Japan Inside Kinmon Manufacturing Co., Ltd. (72) Inventor Hidetaka Branch 2-3-2, Shimura, Itabashi-ku, Tokyo, Japan (72) Inventor Keizo Okawa 1-3-2 Shimura, Itabashi-ku, Tokyo, Japan Incorporated in Kinmon Manufacturing Co., Ltd. (56) References JP-A-48-59443 (JP, A) JP-A-62-206105 (JP, A) JP-A-62-228503 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) E01C 11/26

Claims (4)

(57) [Claims] 1. A structure in which hot water heated by a heat pump heat source device is circulated to a hot water storage tank by a circulation pump, and a part of the hot water in the hot water storage tank is circulated by a water supply pump through a road surface pipe provided on a snow melting road surface. In controlling the snow melting device on the road surface, in order to efficiently operate the heat pump heat source device by controlling the hot water circulation system between the heat pump heat source device and the hot water storage layer, (a) at the time of snowfall, a snow melting mode according to the region road surface heat radiation amount of time (hereinafter, this road heat radiation amount is referred to as a first road load Q _SN.) set, in a time of non-snow, the outside air in the vicinity of the melting snow road and wind speed V _a in the vicinity of the snow melting road surface corresponding to the temperature T _a, the road surface heat radiation amount in the antifreeze and preheat mode (hereinafter, this road heat radiation amount is referred to as a second road load Q _V.) comprising the steps of: defining a (b) the first road load Q _SN and the second road surface Load Q _V
Depending on the steps of determining respectively the lower limit T _L and the upper limit value T _H of the proper temperature range of the return hot water from the hot water tank to the heat pump, the (c) the return current temperature T of the hot water of the hot water storage tank Starting or stopping the heat pump heat source device or increasing or decreasing the heating capability of the heat source device in order to keep the temperature of the hot water within an appropriate temperature range. Control method. 2. The method for controlling a snow melting apparatus according to claim 1, wherein, prior to the step (b), the heat source function power Q _G of the heat pump heat source unit is changed to a heat source corresponding to a heat source temperature T _x. includes a step of determining as a function force Q _G, further steps of (ii), using a heat pump heat source capability to be the upper limit value T _H a defined either as the lower limit value T _L (Q _G) a step of determining, according to the size of the first or second road load (Q _SN or Q _V), fixed to the upper limit value T _H to the first threshold temperature T _HH capable of preventing an excessive operation of the heat pump heat source equipment Then, the lower limit value _TL is fixed to a second limit temperature _TLL for securing the rising time of the snow melting of the road surface snow melting apparatus within an allowable time, or the lower limit value _TL is added to the snow melting road surface by useless use. Third limit to avoid temperature And a step of fixing the temperature T _LH, the heat transfer resistance R between the snow melting road surface and hot water F (m ² h ℃ / kca
l), a coefficient depending on the hot water flow rate I (l / m ² h) and the specific heat C _f (kcal / ° C. 1) of the antifreeze in the road surface pipe, and the first and second road surface loads (Q _SN and Q _V). ) when the collectively represents at Q, the lower limit T _L and _{T L = (T g + F} · Q) ℃, and S _a and snow melting area (m ^2), the antifreeze in the road pipe G Specific heat C _f (kcal /
° C), a coefficient depending on the volume W (l) of the hot water stored in the hot water tank and the operation duration (H) of the heat source unit, Q _e is the surplus heat (kcal / h) of the heat pump heat source unit, and When the first and second road loads (Q _SN and Q _V ) are represented by Q, the upper limit value _TH is _TH = ( _TL + G · Q _e ) ° C. and Q _e = (Q _G −Q) and control method of a road surface snow melting apparatus characterized by a S _a kcal / h. 3. A control method for a road surface snow melting apparatus of claim 1, step a in step (c) of comparing the return current temperature T and the upper limit value T _H of the hot water from in the hot water tank And comparing the current temperature T with the lower limit value _TL; and, when the current temperature T is lower than the lower limit value _TL and the heat source device is stopped, activating the heat source device. the method comprising the heat source unit to the low speed heating condition, wherein when the current temperature T is high and the heat source unit than the upper limit value T _H is in operation, a step of stopping the heat source machine, the current If the temperature T is and the heat pump heat source unit lower than the upper limit value T _H is in operation, the first or the second road load (Q _SN or Q _V) is the heat pump heat source function force Q _G and regions If the product is less than or equal to the product of the dependence coefficient f ₁ In this case, the heat pump heat source unit is set to a low-speed heating state, or the first or second road surface load (Q _SN or Q _SN
If _V) is greater than the product of the heat source function forces and regions dependent coefficient f ₁ is the control method of the road snow melting apparatus which comprises the step of the heat pump heat source apparatuses at a high speed heating condition. 4. The method for controlling a snow melting apparatus according to claim 1, wherein the step (b) further comprises: adjusting a heat source functional force Q _G of the heat pump heat source device to the heat source temperature T _X before the step (b). comparing the step of determining as a heat source function force, and the adoption heat source temperature T _x a track temperature setpoint T _G to be set for the calculation of the second road load in accordance with the environment, the blood collection heat source temperature T _x when said at road set temperature T _G above, the second road load Q _V in order to prevent a malfunction of the control of the road surface snow-melting device and a step that Q _V = 0, the first road load Q _SN When A and B are constants and coefficients determined depending on the roadbed structure, _Tg is a road surface setting temperature (° C.), and _Ta is an outside air temperature (° C.), Second road load Q
_{Let V} be Q _V = (A + B · V _a ) · (T _g -T _a ) kcal / m ² h, let C and D be the intrinsic coefficients of the heat pump heat source unit, and the intrinsic constants of the heat pump heat source unit. Is E, the heat source functional force Q _G is Q _G = Q _GH = ( _{CT ×} T ² + D _× T + E) kcal / m ² h, or Q _G is the heat source temperature T _A method for controlling a snow melting device for a road surface, characterized in that the value corresponds to _x .