JP7390182B2 - Refrigerator floor heating system - Google Patents

Description

The present invention relates to a refrigerator floor heating system that heats the refrigerator floor to prevent the floor from freezing.

BACKGROUND ART Conventionally, floor heating systems have been installed on the floors of refrigerated warehouses, particularly at entrances and exits, in order to prevent moisture from freezing due to the intrusion of outside air, thereby preventing slips and the like.
As shown in Patent Document 1, a conventional floor heating system has an electric heater buried in a certain area of the floor under the opening/closing door of a refrigerator, and the electric heater is continuously energized to warm the floor. It raised the temperature and prevented freezing.

By the way, in recent years, as safety standards have increased, there has been a need to store flammable chemical substances at sub-zero temperatures. In such a case, the refrigerator is also required to be explosion-proof, so in order to reduce the risk of electrical leakage, it is preferable not to provide an electric circuit on the floor inside the refrigerator.
Further, the electric heater as disclosed in Patent Document 1 continuously consumes power of, for example, about 0.75 kW for each entrance/exit, and thus has a problem of high energy cost.

Japanese Patent Application Publication No. 9-133452

An object of the present invention is to provide a floor heating system for a refrigerator that has a low risk of electrical leakage and consumes little electrical energy.

The floor heating system for a refrigerator according to the present invention includes a floor heating panel installed on the floor of the refrigerator, a heat medium flow path provided in the floor heating panel, and a heat medium flow path in the heat medium flow path. a circulation path and a pump for circulating the heat medium; a heat exchanger provided in the circulation path outside the refrigerator for heating the heat medium flowing through the circulation path; A heat exchange device having the heat exchanger and the antifreeze fluid filled in the circulation path is installed in the ceiling of a building housing the refrigerator, and the antifreeze fluid flowing through the circulation path is installed in the heat exchange device. The circulation path is provided with a ceiling flow path that passes through the ceiling of the building and is connected to the heat exchange device.

According to this refrigerator floor heating system, antifreeze is circulated in a floor heating panel installed on the floor of the refrigerator, and the antifreeze flowing in the circulation path outside the refrigerator is heated by a heat exchanger to prevent electrical leakage. It is possible to reduce the risks such as these and reduce the consumption of electrical energy. Furthermore, by using antifreeze as a heating medium, even if the circulation of the heating medium stops or becomes insufficient, it is possible to prevent the heating medium from freezing.
In addition, the provision of a ceiling passage allows the antifreeze to be heated by the heat from the ceiling of the building, which is heated by solar heat. In addition to reducing the risk of circulation failure, when the amount of heat generated by the heat exchanger and solar heat is insufficient, the antifreeze can be heated with an electric heater to prevent freezing. Furthermore, since the electric heater is located in a heat exchanger installed in the ceiling of the building, there is a low risk of electrical leakage, and there are no explosion-proof problems.

The heat exchanger may exchange heat between the antifreeze and an external heat source including at least one of outside air, waste water, solar heat, and waste heat from an external heat exchanger. In this case, it is possible to further reduce the cost required for heating energy.

The floor heating panel includes a panel lower layer, a support provided on the panel lower layer, a heat medium flow path supported in a fixed shape by the support, and a panel upper layer provided on the heat medium flow path. It may have. In this case, the support body has the advantage that the shape of the heat medium flow path can be set relatively freely, and the floor heating panel can be easily assembled, so it is easy to prefabricate it, assemble it at a factory, and install it on site. become.

The heat medium flow path provided in the floor heating panel may be formed into a meandering shape or the like by bending a tube made of metal such as copper or copper alloy, or plastic such as polyethylene. In this case, the weight of the floor heating panel can be reduced, and manufacturing costs can be kept low.

The circulation path may be provided with an expansion tank for allowing a change in volume of the antifreeze due to a change in temperature. In this case, even if the temperature of the antifreeze changes and the volume of the antifreeze changes, it is easy to keep the pressure in the circulation path within a relatively small fluctuation range.

The floor heating panel includes a wire mesh as the support provided on the lower layer of the panel, a heat exchange pipe as the heat medium flow path supported by the wire mesh, and the heat exchange pipe at a plurality of locations. The heat exchange pipe may include a binding part that is fixed to the wire mesh to maintain the shape of the heat exchange pipe, and the panel upper layer provided on the heat exchange pipe.

As described above, according to the present invention, by circulating antifreeze in the floor heating panel and heating the antifreeze with a heat exchanger outside the refrigerator, the risk of electrical leakage etc. is reduced and the consumption of electrical energy is also reduced. It is possible to suppress it.

1 is a front view of a floor heating system of a refrigerator according to an embodiment of the present invention. It is a top view showing the arrangement state of the floor heating panel of the same embodiment. FIG. 3 is a plan view showing the floor heating panel of the same embodiment with the panel upper layer removed. It is a longitudinal cross-sectional view showing a state in which the floor heating panel of the same embodiment is buried in the floor of the refrigerator. It is a block diagram showing the flow of a heat medium of the same embodiment.

An embodiment of a refrigerator floor heating system according to the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 is a front view showing a refrigeration equipment 1 to which a floor heating system of the present embodiment is applied. The refrigerator has three refrigerators 2A, 2B, and 2C. Although only one refrigerator is sufficient, the energy cost reduction effect of the present invention becomes more significant when there are multiple refrigerators. Each of the refrigerators 2A, 2B, and 2C each has, for example, a rectangular doorway, and each doorway is provided with a rectangular heat insulating door 4 that opens and closes from side to side automatically or manually. However, the shape of each of the above parts is not limited to a rectangular shape, and may be changed as necessary.

Below each heat insulating door 4, as shown in FIG. 2 (plan view), a floor heating panel 6 having a rectangular shape in plan view and a constant thickness is installed parallel to the floor F. As shown in FIG. 3, the floor heating panel 6 is preferably embedded in a rectangular panel housing portion 18 of the same shape formed on the floor F so as to be flush with the floor F in order to eliminate steps. has been done. The floor heating panel 6 may be assembled in advance at a factory and subsequently buried in the panel housing section 18, or may be assembled inside the panel housing section 18. Furthermore, it may be removable from the panel housing portion 18 or may be non-removable. Although not shown, it is preferable to seal the space between the upper edge of the floor heating panel 6 and the upper edge of the panel accommodating portion 18 with a caulking agent or the like.

The floor heating panel 6 has a width that is approximately the same as the width of the heat insulating door 4, and is disposed along the left and right direction of the heat insulating door 4 in its longitudinal direction. The depth of the floor heating panel 6 in this example is smaller than the above-mentioned width, and the insulating door 4 is located almost in the center of the depth, that is, a part of the floor heating panel 6 is placed inside the refrigerators 2A, 2B, and 2C. The other parts are arranged outside the refrigerators 2A, 2B, and 2C. However, the arrangement of the floor heating panel 6 is not limited to the illustrated state, and if necessary, the entire floor heating panel 6 may be arranged inside the refrigerators 2A, 2B, and 2C.

Each floor heating panel 6 has a built-in heat exchange pipe 24 (see FIG. 3), and at both ends of the heat exchange pipe 24, there is a downstream flow path 8A and an upstream flow path for circulating antifreeze as a heat medium. 8B, and these downstream flow path 8A and upstream flow path 8B extend to the ceiling of the building through the inside of the building wall near the heat insulating door 4, and are connected to the ceiling flow path 10. The ceiling flow path 10 mainly passes through the ceiling of the building, and is heated by the solar heat absorbed by the ceiling or the outside temperature. A heat exchange device 12 is installed on the ceiling of the building of the refrigeration equipment 1 in this example, and the heat exchange device 12 includes a heat exchanger 14 and a fan 16 that blows outside air onto the heat exchanger 14 to heat it .

3 is a plan view showing the internal structure of the floor heating panel 6, and FIG. 4 is a longitudinal cross-sectional view showing the floor heating panel 6 buried in the floor F. The floor heating panel 6 includes a panel lower layer 20 having a constant thickness and a rectangular shape, a wire mesh 22 placed on the panel lower layer 20, a heat exchange pipe 24 placed on the upper surface of the wire mesh 22, and all of these. and a panel top layer 28 fixed over the panel.

The panel lower layer 20 is formed of concrete, plastic, wood, ceramics, etc., and may be a single layer or a multilayer having one or more of a heat insulating layer, a waterproof layer, and an adhesive layer. It may be a structure. If it has a heat insulating layer made of a porous material such as plastic, it is possible to suppress downward heat conduction and increase thermal efficiency. Having a waterproof layer has the effect of preventing corrosion of the heat exchange pipe 24 and wire mesh 22 due to water intrusion from the front side of the floor heating panel 6 and water permeation from the bottom side.

The wire mesh 22 is formed by arranging wires made of a material with high mechanical strength, such as stainless steel, iron, or iron alloy, in a grid or net shape, and is generally the same as the floor heating panel 6, or It has a rectangular shape with slightly smaller dimensions. The wire mesh 22 may have the strength to maintain its rectangular shape during transportation, or may be folded or rolled up into a roll for transportation. The size of the grid (pitch between parallel adjacent wires) is not limited, but if it is about 10 to 20 cm, the heat exchange pipes 24 can be easily fixed at appropriate intervals. The thickness of the wire of the wire mesh 22 is not limited, but it depends on the material, but it is usually easy to handle if it is about 3 to 4 mm.

The material of the heat exchange pipe 24 is not limited, and the heat exchange pipe 24 is, for example, a pipe body made of metal such as copper, copper alloy, brass, aluminum, or aluminum alloy, or plastic such as polyethylene or polybdenum, and the dimensions thereof are not limited. However, it is preferable that the inner diameter is about 13 to 20 mm and the wall thickness is about 1.0 to 2.5 mm, for example. The heat exchange pipe 24 of this embodiment has a plurality of straight portions extending in the width direction of the floor heating panel 6 and a U-shaped portion connecting both ends of the adjacent straight portions, and has a meandering shape as a whole when viewed from above. It has a shape. However, the planar shape of the heat exchange pipe 24 is not limited to the illustrated shape, and may be a meandering shape having a straight portion extending in the depth direction of the floor heating panel 6, or a double spiral shape as a whole. Good too. The arrangement density of the heat exchange pipes 24 is preferably substantially uniform over the entire surface of the floor heating panel 6. Although the arrangement pitch of the straight portions of the heat exchange pipe 24 is not limited, it is preferably about 100 to 200 mm. Both ends of the heat exchange pipe 24 may extend outward from the end surface or surface of the floor heating panel 6, or may be open to the surface or end surface of the floor heating panel 6. Connectors and screws for connection to the downstream flow path 8A and the upstream flow path 8B may be provided at both ends of the heat exchange pipe 24.

The binding portion 26 is for fixing the heat exchange pipe 24 to the wire mesh 22 at multiple locations to maintain the shape of the heat exchange pipe 24, and the material and shape thereof are not limited, but may be made of, for example, metal wire, plastic, or The overlapping portion of the wire mesh 22 and the heat exchange pipe 24 may be fastened using a cable or string made of fiber or the like, or a special jig made of metal or plastic. A hook-shaped binding portion 26 may be formed on the wire mesh 22 itself, and the heat exchange pipe 24 may be engaged therewith.

The panel upper layer 28 is formed by arranging the wire mesh 22 and the heat exchange pipes 24 on the panel lower layer 20, and then stacking them on the panel lower layer 20 so as to embed the wire mesh 22 and the heat exchange pipes 24. The material of the panel upper layer 28 is not limited, but it may be made of concrete, plastic, ceramics, etc., and may be a single layer, a waterproof layer, a decorative layer, an abrasion resistant layer, an anti-slip layer, and an adhesive layer. It may be a multilayer structure having one or more of the following. If the waterproof layer is provided, the effect of preventing corrosion of the heat exchange pipe 24 and the wire mesh 22 due to water intrusion from the surface side of the floor heating panel 6 can be obtained.

The dimensions of the floor heating panel 6 are not limited and may be matched to the size of the entrance/exit of the refrigeration equipment 1 and the insulation door 4, but for a general refrigeration equipment 1, the width (longitudinal direction) is 200 to 300 cm, It is preferable that the depth (in the short direction) is about 100 to 200 cm. The thickness from the heat exchange pipe 24 to the surface of the floor heating panel 6 is also not limited, but in consideration of heat conduction, it is preferably about 5 to 10 cm.

The antifreeze solution (brine) is preferably one that does not freeze even at the set temperature in the refrigerators 2A, 2B, and 2C. For general refrigeration equipment 1, for example, an antifreeze solution that does not freeze even at -25°C is preferable. The antifreeze solution may have a conventional composition, such as ethylene glycol, propylene glycol, glycerin, aqueous solutions of various salts, and mixtures of two or more thereof.

Next, the heat medium path will be explained using FIG. 5. A downstream flow path 8A and an upstream flow path 8B are connected to both ends of the heat exchange pipe 24 of each floor heating panel 6, respectively, and the downstream flow path 8A and the upstream flow path 8B are connected, for example, to It reaches the ceiling of the refrigeration equipment 1 along the frame walls on both sides of the refrigerator 4, and is connected to a ceiling channel 10 disposed within or on the ceiling. The ceiling channel 10 has a supply channel 38 and a reflux channel 40, the upstream channel 8B is connected to the supply channel 38, and the downstream channel 8A is connected to the reflux channel 40. As shown in FIG. 1, the ceiling channel 10 may be provided with a solar panel 80 that collects or retains solar heat to heat the ceiling channel 10.

A valve 30 and a thermometer 34 are respectively connected to the downstream flow path 8A, and a valve 32 and a thermometer 36 are similarly connected to the upstream flow path 8B. The supply path 38 reaches the heat exchange device 12 and is connected to the heat exchanger tube 44 of the heat exchanger 14 via a switching valve 46 . The other port of the switching valve 46 is connected to the reflux path 40 via a pump 48 and a thermometer 50, and when the switching valve 46 is operated, the supply path 38 is connected to the heat transfer tube 44 or the pump 48 and the thermometer are connected. Either the supply path 38 and the reflux path 40 can be short-circuited via the reflux path 50. Normally, the supply path 38 is connected to the heat exchanger tube 44 by the switching valve 46 and the antifreeze is heated by the heat exchanger 14, but when heating is not necessary or when maintenance of the heat exchanger 14 is performed, , the supply path 38 is short-circuited to the reflux path 40 via the pump 48 and the thermometer 50 by the switching valve 46, and the pump 48 is further operated so that the antifreeze can be circulated without passing through the heat exchanger 14. It has become.

The supply path 38 is also connected to the inlet side of the heat exchanger 14 within the heat exchange device 12 via an electric heater 54 and a pump 52, and when the pump 52 is operated, at least part of the antifreeze from the reflux path 40 is removed. The antifreeze liquid can be fed into the electric heater 54, and the electric heater 54 can heat the antifreeze liquid. The pump 52 and the electric heater 54 are connected to a control panel (not shown), and when the antifreeze is not sufficiently heated by the heat exchanger 14, the pump 52 and the electric heater 54 heat some or all of the antifreeze and supply floor heating from the supply path 38. It serves to increase the temperature of the entire antifreeze solution supplied to the panel 6. Pump 52 and electric heater 54 are used only when necessary and are not normally operated.

A pump 56 is provided in the reflux path 40, and the pump 56 sends the antifreeze returned from the reflux path 40 to the heat exchanger 14, and the antifreeze heated in the heat exchanger 14 is sent to the floor heating panel via the supply path 38. Send to 6. An expansion tank 70 is connected to the upstream side of the pump 56 via a valve 58 and a valve 68, and when the valve 58 and the valve 68 are opened, a portion of the antifreeze liquid flows into the expansion tank 70. This allows the pressure within the system to be maintained within a certain range even if the antifreeze in the entire circulation path expands or contracts due to temperature changes.

A pressurized tank 74 (pressurized cistern) is connected to the downstream side of the valve 58, and this pressurized tank 74 is connected to an antifreeze tank (not shown) via the valve 78. A valve 76 is also connected to the pressurized tank 74, and when the valve 76 is opened, drain is discharged. Further, the valve 58 and the valve 78 are short-circuited through the valve 72, and when both the valve 72 and the valve 58 are opened, the antifreeze from the antifreeze tank can be directly flowed into the supply path 38.

A pump 62 is connected to the upstream side of the pump 56 via a valve 60 and connected to a first discharge path (not shown), and a valve 64 and a pump 66 are also connected to the downstream side of the pump 56 (not shown). It is connected to a second discharge path. By operating these valves 60 and 64, as well as pump 62 and pump 66, the antifreeze in the system can be replaced.

Next, the operation of the above refrigerator floor heating system will be explained. The low temperature (e.g., 7° C.) antifreeze returned from the reflux path 40 by the pressure of the pump 56 exchanges heat with the outside air supplied by the fan 16 while flowing through the heat exchanger tubes 44 of the heat exchanger 14, and ℃). The antifreeze flowing out from the heat transfer tube 44 passes through the switching valve 46, flows through the supply path 38, passes through the ceiling flow path 10, further increases in temperature slightly, and then passes through the upstream flow path 8B to the floor heating panel 6. It flows through the heat exchange pipe 24. The circulation rate of the antifreeze in the system is not limited, but may be about 5 to 10 L/min per floor heating panel 6. The pressure of the antifreeze in the system is also not limited, but may be about 0.1 to 0.3 MPa.

While the antifreeze fluid flows through the heat exchange pipe 24, the floor heating panel 6 is warmed by the temperature of the antifreeze fluid, and the surface temperature of the floor heating panel 6 becomes 0° C. or higher. Thereby, even when the heat insulation door 4 is opened and outside air enters the refrigerators 2A, 2B, and 2C, moisture in the outside air can be prevented from freezing on the surface of the floor heating panel 6. The antifreeze cooled to a low temperature (for example, 7° C.) by heating the floor heating panel 6 flows through the ceiling flow path 10 through the downstream flow path 8A, and after being slightly warmed, it flows through the return flow path 40. After that, it is pressurized by the pump 56 and heated again to a high temperature (for example, 9° C.) by the heat exchanger 14.

If the pressure of the antifreeze in the system becomes too high, valves 58 and 68 are opened to allow the antifreeze to flow into the expansion tank 70 to adjust the pressure. When the antifreeze in the system is insufficient, valves 58 and 78 are opened to replenish the system with antifreeze from an external antifreeze supply tank. Furthermore, by operating the valve 60 and pump 62, the antifreeze in the system can be replaced and the amount can be adjusted.

If the outside temperature is too low and the antifreeze is not sufficiently warmed by the heat exchanger 14, the pump 52 and the electric heater 54 are operated to heat some or all of the antifreeze by the electric heater 54, and the supply path 38 The temperature of the antifreeze flowing through the pipe is raised to a high temperature (for example, 9°C). If the temperature of the antifreeze liquid returned from the reflux path 40 is too high, check the temperature with the thermometer 50, operate the switching valve 46 to operate the pump 48, and transfer the antifreeze liquid returned from the reflux path 40 to the heat exchanger. It returns to the supply path 38 without passing through 14. With the above adjustments, the refrigerator floor heating system will operate stably.

According to the floor heating system for a refrigerator having the above configuration, antifreeze is circulated within the floor heating panel 6 installed on the floor F of the refrigeration equipment 1, and the antifreeze flows through the circulation path outside the refrigerators 2A, 2B, and 2C. By heating with the heat exchanger 14, it is possible to reduce the risk of electrical leakage and the like, and also to suppress the consumption of electrical energy. For example, compared to conventional systems that consume about 0.75 kW of power per panel, this embodiment uses only about 1 kW of power even though it is configured to heat a plurality of floor heating panels 6. Can be done. If the number of floor heating panels 6 is increased, the power cost per panel can be further reduced. Further, by using antifreeze as a heating medium, even if the circulation of the heating medium is stopped or becomes insufficient, it is possible to prevent the heating medium from freezing in the floor heating panel 6 and the circulation path.

Furthermore, since the heat exchanger 14 exchanges heat between the outside air and the antifreeze, it is possible to further reduce the cost required for heating energy. The heat exchanger 14 may exchange heat between the antifreeze and an external heat source containing at least one of waste heat from a factory, solar heat, and waste heat from a heat exchanger outside the system instead of outside air. good.

The floor heating panel 6 also includes a lower panel layer 20, a wire mesh 22 as a support provided on the lower panel layer 20, a heat exchange pipe 24 supported in a fixed shape by the wire mesh 22, and an upper layer of these. Since the panel upper layer 28 is provided in It is also easy to assemble it in a factory, fit it into the panel accommodating part 18 on site, and fix it with caulking agent, adhesive, concrete, etc.

In addition, the heat exchange pipe 24 provided in the floor heating panel 6 is formed into a meandering shape by bending a tube made of metal such as copper or copper alloy or plastic such as polyethylene. The weight of the heating panel 6 can be reduced, and manufacturing costs can be kept low.

Furthermore, since the circulation path is provided with an expansion tank 70 to allow the volume to change due to changes in the temperature of the antifreeze, even if the temperature of the antifreeze changes and the volume of the antifreeze changes, the pressure in the circulation path is maintained. It is easy to suppress the variation within a relatively small range.

Furthermore, since the circulation path is provided with a ceiling passage 10 that passes through the ceiling of the building of the refrigeration equipment 1, the solar heat stored in the ceiling can be used to heat the heating medium, and damage to the building can be avoided. Even if this occurs, the risk of the heating medium becoming unable to circulate can be reduced by passing through the ceiling, which is less likely to be damaged.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and may be combined with other well-known configurations, or may exclude non-essential constituent elements of the above embodiments. It's okay.

According to the present invention, by circulating antifreeze in the floor heating panel and heating the antifreeze with a heat exchanger outside the refrigerator, it is possible to reduce the risk of electrical leakage, etc., and to reduce the consumption of electrical energy. , the present invention is industrially applicable.

1 Refrigeration equipment 2A, 2B, 2C Refrigerator 4 Insulation door 6 Floor heating panel 8A Downstream flow path 8B Upstream flow path 10 Ceiling flow path 12 Heat exchange device 14 Heat exchanger 16 Fan 18 Panel housing portion 20 Panel lower layer 22 Wire mesh 24 Heat exchange pipe 26 Binding part 28 Panel upper layer 30 Valve 32 Valve 34 Thermometer 36 Thermometer 38 Supply path 40 Reflux path 44 Heat transfer tube 46 Switching valve 48 Pump 50 Thermometer 52 Pump 54 Electric heater 56 Pump 58 Valve 60 Valve 62 Pump 64 Valve 66 Pump 68 Valve 70 Expansion tank 72 Valve 74 Pressure tank 76 Valve 78 Valve 80 Solar panel F Floor

Claims (6)

A refrigerator floor heating system,
a floor heating panel installed on the floor of the refrigerator;
a heat medium flow path provided in the floor heating panel;
a circulation path and a pump for circulating a heat medium in the heat medium flow path;
a heat exchanger provided in the circulation path outside the refrigerator for heating the heat medium flowing in the circulation path;
an antifreeze solution filled in the heat medium flow path and the circulation path as the heat medium ;
A heat exchange device having the heat exchanger is installed in the ceiling of a building housing a refrigerator,
An electric heater for heating the antifreeze flowing through the circulation path is provided in the heat exchange device,
A floor heating system for a refrigerator, wherein the circulation path is provided with a ceiling flow path that passes through the ceiling of the building and is connected to the heat exchange device. The refrigerator according to claim 1, wherein the heat exchanger exchanges heat between the antifreeze and an external heat source containing at least one of outside air, waste water, solar heat, and waste heat from an external heat exchanger. floor heating system. The floor heating panel includes a panel lower layer, a support provided on the panel lower layer, a heat medium flow path supported in a fixed shape by the support, and a panel upper layer provided on the heat medium flow path. The floor heating system for a refrigerator according to claim 1 or 2, comprising: The refrigerator according to any one of claims 1 to 3, wherein the heat medium flow path provided in the floor heating panel is formed by bending a tube made of metal or plastic. floor heating system. The refrigerator floor heating system according to any one of claims 1 to 4, wherein the circulation path is provided with an expansion tank for allowing a volume change due to a temperature change of the antifreeze liquid. . The floor heating panel includes a wire mesh as the support provided on the lower layer of the panel, a heat exchange pipe as the heat medium flow path supported by the wire mesh, and the heat exchange pipe at a plurality of locations. 4. The refrigerator floor according to claim 3, further comprising: a binding part fixed to the wire mesh to maintain the shape of the heat exchange pipe; and the panel upper layer provided on the heat exchange pipe. warming system.

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