JP3464601B2 - Thermal storage snow melting equipment using heat pump - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly applied to a road surface snow melting facility or the like that heats and melts snow accumulated on a road surface by radiating heat transfer water flowing in a heat radiation pipe installed under the road surface. The present invention relates to a heat storage type snow melting facility using a heat pump.

[0002]

2. Description of the Related Art As shown in FIG. 4, a heat storage type snow melting facility using a heat pump of this type has a high temperature refrigerant absorbing heat from a low temperature heat source (air or water) and a portion below the road surface where snow melting is required. A heat pump 2 having a condenser 3 that indirectly heat-exchanges with the heat transfer water (warm water) flowing in the heat radiating pipe for snow melting 1 laid in a zigzag shape, and the heat of the heat transfer water. And a heat storage tank 4 for collecting and storing heat. The temperature is raised by heat exchange in the condenser 3 between the heat storage tank 4 and the heat pump 2, and between the snow melting radiation pipe 1 and the heat pump 2. The heat medium water forced circulation paths 6A and 6B for forcibly circulating the heat medium water to the heat storage tank 4 and the snow melting radiating pipe 1 via the pump 5 are configured so as to share a part of these circulation paths. , Of these both heat medium water forced circulation paths 6A, 6B Near the inlet of the secondary circulation path, the heat transfer water that has been controlled to be opened and closed by the command operation from the outside and is heated by the heat exchange in the condenser 3 is passed through one heat transfer water forced circulation path 6A. A heat storage operation state in which forced circulation is performed between the heat storage tank 4 and the other heat medium water forced circulation path 6
Motor operated valve devices 7A, 7 capable of switching to a snow-melting operation state in which forced circulation is carried out between the snow-melting heat radiation pipe 1 and B through B.
B is interposed and a temperature control mixing three-way valve 8 is arranged at the confluence of both of the forced circulation paths 6A and 6B.

In the heat storage type snow melting equipment using a heat pump having the above-mentioned structure, a heat storage operation for storing the amount of heat generated by the heat pump is performed when there is no snowfall, and a snowmelt operation for switching the heat generation amount and the heat storage amount by the heat pump is used during snowfall. In comparison with snow melting equipment that does not have a heat storage tank, the capacity of the heat pump is almost halved, downsizing of the equipment as a whole, economic efficiency and reduction of running cost due to reduction of power consumption are achieved, and a large amount of snowfall occurs. Also has the advantage of being able to secure a snowmelt output that can be sufficiently dealt with.

By the way, in the heat storage type snow melting equipment using a heat pump having the above configuration and advantages, the means for utilizing the heat in the heat storage tank 4 during the snow melting operation is as shown in FIG.
The temperature of the point, that is, the temperature of the return heat transfer water to the condenser 3 of the heat pump 2 is detected by a temperature sensor, and the heat storage tank 4 of the temperature control mixing three-way valve 8 is maintained so that the detected temperature is maintained at a predetermined temperature. Generally, a method of automatically controlling the opening of the connection side port 8-1 is used.

[0005]

However, when the heat storage utilizing means as described above is adopted, the temperature of the return heat transfer medium water to the condenser 3 of the heat pump 2 reaches the predetermined temperature regardless of the fluctuation of the snow melting load. Since the output of the heat storage tank 4 is controlled so as to be maintained, it is unnecessary from the heat storage tank 4 even though the output of the heat pump 2 itself decreases only within a range not exceeding the snow melting load. There is a problem in that the amount of heat is taken out, resulting in wasting of the amount of heat stored, resulting in an increase in power consumption.

The present invention has been made in view of the above circumstances, and maximizes the amount of heat generated by a heat pump to preserve the amount of stored heat as much as possible, while exhibiting a sufficient and sufficient snow-melting ability even under a large snow-melting load. It is an object of the present invention to provide a heat storage type snow melting facility that uses a heat pump.

[0007]

In order to achieve the above object, a heat storage type snow melting equipment using a heat pump according to the invention as defined in claim 1 is a heat radiating pipe for snow melting and heat flowing in the radiating pipe for snow melting. A heat pump having a condenser for raising the temperature of the medium water by heat exchange with a high-temperature refrigerant, a heat storage tank for recovering and storing the heat of the heat medium water, and a heat raised by heat exchange in the condenser of the heat pump. Forced circulation of heat transfer medium having a valve device capable of switching between a heat storage operation state in which medium water is forcedly circulated between the heat storage tank and a snow melting operation state in which forced circulation is performed between the snow melting radiating pipe Path, and a heat storage type snow melting facility using a heat pump provided with a heat medium water forced circulation path in the heat storage operation state and a mixing three-way valve for temperature adjustment arranged at the confluence of the heat medium water forced circulation path in the snow melting operation state And the above When the temperature drop in the above-mentioned snow melting radiant pipe is larger than the set value with respect to the heat transfer water temperature at the pump outlet, always return the heat transfer water temperature to the condenser of the heat pump to a temperature lower by the set value. It is characterized in that a controller is provided for automatically controlling the opening of the connection port of the temperature control mixing three-way valve to the heat storage tank.

According to the invention of claim 1 having the above-mentioned structure, the heat medium water forced circulation path in the heat storage operation state and the heat medium water forced circulation path in the snow melting operation state are arranged at the confluence portion. Keep the opening of the connection port of the temperature control mixing three-way valve to the heat storage tank so that the temperature of the heat transfer water returning to the heat pump condenser is always lower than the heat transfer water temperature at the outlet of the heat pump by the set value. By automatic control to
When the snowmelt load is smaller than the output of the heat pump, the output from the heat storage tank is suppressed to zero, and when the snowmelt load exceeds the output of the heat pump, the insufficient amount of heat is supplemented by the output from the heat storage tank. Become. As a result, when the output of the heat pump itself is reduced only within a range that does not exceed the snow melting load, the heat amount is not unnecessarily taken out from the heat storage tank, and the heat storage amount can be saved as much as possible.

In particular, as described in claim 2, when the snowmelt load is smaller than the 100% output of the heat pump during the snowmelt operation, the heat pump is operated in accordance with it, and the snowmelt load is higher than the 100% output of the heat pump. If it is too large, the operation of the heat pump is prioritized during the snow melting operation by configuring to continue operating at 100% output, and the amount of heat taken out from the heat storage tank is minimized to the minimum necessary to reduce power consumption. It becomes possible to do.

In the heat storage type snow melting equipment using a heat pump as described above, as described in claim 3, a road surface for melting the snow accumulated on the road surface by laying the heat radiating pipe for snow melting under the road surface. It can be effectively applied as snow melting equipment and equipment for preventing freezing, but in addition to that, it can also be applied to melting snow on the roof surface of buildings and melting snow on the ground surface. .

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are configuration diagrams showing an outline of a heat storage type snow melting facility using a heat pump according to the present invention, in which 1 to 5, 6A, 6B, 7A and 7B are shown.
Since and 8 are the same as the components of the equipment shown in FIG. 4, the same reference numerals are given to the corresponding portions, and the description thereof will be omitted. Note that the heat pump 2 includes an expansion valve, an evaporator, a liquid receiver, a compressor, and the like in addition to the condenser 3, but these are well known, so a detailed description and illustration thereof are omitted. Further, this heat pump 2 performs a corresponding operation when the snow melting load is smaller than 100% output of the heat pump during the snow melting operation, and continues the operation of 100% output when the snow melting load is larger than 100% output of the heat pump. Is configured to. Furthermore, the heat storage tank 4
The method may be either a sensible heat storage method using hot water or a latent heat storage method using a phase change substance.

In the heat storage type snow melting facility using a heat pump having the above-mentioned basic structure, the heat pump 2
Water temperature T of the outlet b of the snow
3 and a temperature sensor 10 for detecting the temperature T2 of the heat transfer water returned to the condenser 3 of the heat pump 2 in the vicinity c of the outlet side port 8-3 of the temperature control mixing three-way valve 8 are provided. Based on the temperatures T3 and T2 detected by the temperature sensors 9 and 10, the latter heating medium water temperature T2 is always kept lower than the former heating medium water temperature T3 by the set temperature (ΔT). A programmable controller 11 for automatically controlling the opening of a port 8-1 on the connection side of the temperature control mixing three-way valve 8 with the heat storage tank 4 is provided.

The set temperature ΔT is ΔT = Q / F · C1 = T3−T2, where Q is the amount of heat when the output of the heat pump 2 is 100% and F is the circulating amount of the heat medium water. C1: The specific heat of the circulating heat transfer water is determined to hold.

Next, the operation of the heat storage type snow melting equipment using the heat pump constructed as described above when the snow melting radiation pipe 1 is laid under the road surface and used as the road surface snow melting equipment will be described. When there is no snowfall, one electric valve device 7A is opened and the other electric valve device 7B is closed by a command operation from the outside, and the temperature adjusting mixed three-way valve 8 is used.
The two ports 8-1 and 8-3 are connected to each other, and as shown in FIG. 1, the heat transfer water heated by the heat exchange in the condenser 3 of the heat pump 2 passes through the pump 5 to the one side. The heat storage operation state is achieved in which the heat medium is forcedly circulated through the heat medium water forced circulation path 6 </ b> A to the heat storage tank 4. In this operating state, the heat of the heat transfer water is recovered and stored in the heat storage tank 4.

Then, at the time of snowfall, one electric valve device 7A is closed and the other electric valve device 7B is opened by a command operation from the outside, and the condenser 3 of the heat pump 2 is operated as shown in FIG. The heat transfer water heated by the heat exchange is switched to the snow melting operation state in which the heat transfer water is forcedly circulated through the pump 5 through the other heat transfer water forced circulation path 6B to the heat radiating pipe 1 for snow melting, and the heat radiation is performed. The heat radiated from the pipe 1 melts the snow accumulated on the road surface.

During the snow-melting operation, the temperature T9 of the heat transfer water at the outlet of the heat pump 2 is detected by the temperature sensor 9, and the temperature T2 of the return heat transfer water to the condenser 3 is detected by the temperature sensor 10. Both detection temperatures T
3, based on T2, T2 is set temperature ΔT with respect to T3
The programmable controller 11 automatically controls the opening degree of the connection side port 8-1 of the temperature control mixing three-way valve 8 with the heat storage tank 4 so as to keep the temperature as low as possible. As a result, as shown in FIG.
When the snowmelt load exceeds 100% output of the heat pump 2, the output from the heat storage tank 4 is suppressed to zero when it is smaller than 100% output of the heat pump 2, and the output of the heat pump 2 is also controlled according to the snowmelt load. By continuing the operation of the heat pump 2 at 100% output and supplementing the insufficient heat amount with the output from the heat storage tank 4, it is possible to ensure a predetermined snow melting function even when the amount of snowfall is large.

The heat storage type snow melting equipment using a heat pump of the present invention can be effectively applied as road surface snow melting equipment and frost prevention equipment as described in the above embodiment.
In addition to this, even if it is applied to, for example, snow melting on the roof of a building or snow on the ground, similar to the above, the combined use of a small capacity heat pump and a heat storage tank will almost double the output equivalent to the heat pump capacity. It is possible to exert the output of.

[0018]

As described above, according to the invention as set forth in claim 1, the heat pump is used in combination with the amount of heat generated by the heat pump and the amount of heat recovered in the heat storage tank, as compared with the snow melting equipment having no heat storage tank. The capacity of the snow pump is almost halved, the running cost is reduced by downsizing the entire facility, economic efficiency and power consumption, and it is possible to cope with a large amount of snowfall. Is small, the output from the heat storage tank is suppressed to zero, and
Only when the output of the heat pump itself is decreasing, for example, when the snowmelt load exceeds the output of the heat pump, the insufficient amount of heat is compensated for by the output from the above-mentioned heat storage tank. The effect of being able to reliably and sufficiently exhibit the snow melting capacity even under a large snow melting load while preserving the stored heat amount as much as possible without taking out the heat is obtained.

In particular, according to the invention as set forth in claim 2, in addition to the effect of the invention as set forth in claim 1, the extraction of the amount of heat from the heat storage tank is minimized to maximize the power consumption. It can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of a heat storage type snow melting facility using a heat pump according to the present invention, showing a heat storage operation state.

FIG. 2 is a schematic diagram showing a snow-melting operation state, which is an outline of a heat storage type snow-melting facility using a heat pump.

FIG. 3 is a characteristic graph for explaining the relationship between the snow melting load and the outputs of the heat pump and the heat storage tank during the snow melting operation in the heat storage type snow melting facility using the heat pump.

FIG. 4 is a general schematic configuration diagram of a heat storage type snow melting facility using a heat pump.

[Explanation of symbols]

1 Radiant pipe for snow melting 2 heat pump 3 condenser 4 heat storage tank 6A, 6B Heated water forced circulation circuit 7A, 7B Electric valve device 8 Mixing three-way valve for temperature control 9,10 Temperature sensor 11 programmable controller

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Claims (3)

(57) [Claims] 1. A heat-dissipating pipe for snow melting, a heat pump having a condenser for raising the temperature of heat-transfer water flowing through the heat-dissipating pipe for snow-melting by heat exchange with a high-temperature refrigerant, and heat for collecting the heat-transfer water to store heat. Between the heat storage tank and the heat radiating pipe for snow melting and the heat storage operation state in which the heat transfer water heated by heat exchange in the condenser of the heat pump is forcedly circulated between the heat storage tank At the confluence of the heat transfer medium forced circulation path having a valve device capable of switching to the snow melting operation state of forced circulation, and the heat transfer medium forced circulation path in the heat storage operation state and the heat transfer medium forced circulation path in the snow melting operation state. A heat storage type snow melting facility using a heat pump equipped with a temperature control mixing three-way valve, wherein the temperature drop in the snow radiating pipe for the heat transfer water temperature at the outlet of the heat pump is lower than a set value. Heat when big It is equipped with a controller that automatically controls the opening of the connection port with the heat storage tank of the mixing three-way valve for temperature control so that the temperature of the heat transfer water returned to the condenser of the pump is always kept lower by the set value. A heat storage type snow melting facility using a heat pump. 2. The heat pump performs a corresponding operation when the snow melting load is smaller than 100% output of the heat pump during the snow melting operation, and when the snow melting load is larger than 100% output of the heat pump, the heat pump outputs 100% output. The heat storage type snow melting equipment using a heat pump according to claim 1, which is configured to continue operation. 3. The heat storage type snow melting facility using a heat pump according to claim 1 or 2, wherein the snow melting radiating pipe is laid below a road surface to melt snow accumulated on the road surface.