JP5793431B2 - Heating system - Google Patents

Description

  The present invention relates to a heating device. In particular, the present invention relates to a heat storage type heating apparatus having a tank for storing a heated heat medium.

  Patent Document 1 discloses a heat storage type heating device. This heating device includes a tank that stores a heat medium, a heat source device that heats the heat medium, and a heating terminal that heats the heat medium by releasing heat. The tank and the heat source device are connected by a circulation path for heat storage that circulates the heat medium, and the tank and the heating terminal are connected by a circulation path for heating that circulates the heat medium. The heat storage circulation path and the heating circulation path are provided independently of each other.

JP 2010-175163 A

  In the heat storage type heating device, the heat medium heated by the heat source machine is temporarily stored in a tank and then sent to the heating terminal. Therefore, the temperature of the heat medium sent to the heating terminal is relatively stable regardless of the operation state of the heat source machine. However, as the amount of heat stored in the tank decreases, the temperature of the heat medium sent from the tank to the heating terminal is easily affected by the heat medium returned from the heat source unit to the tank. In this case, if the output of the heat source machine (that is, the heating amount of the heat medium) can be finely adjusted, temperature fluctuations of the heat medium sent to the heating terminal can also be suppressed. However, if the heat source device is a heat pump, particularly a heat pump using carbon dioxide as a refrigerant, or a fuel cell, it is difficult to finely adjust the output. In this case, temperature variation of the heat medium sent to the heating terminal cannot be avoided.

  In view of the above problems, the present invention aims to suppress temperature fluctuations of the heat medium sent to the heating terminal even in the case where a heat pump or fuel cell using carbon dioxide as a refrigerant is employed in the regenerative heating device. To do.

A heating apparatus according to the present invention includes a tank for storing a heat medium, a heat source device for heating the heat medium, a heat storage outbound path for sending the heat medium from the tank to the heat source apparatus, and a heat storage return path for returning the heat medium from the heat source apparatus to the tank. And a heating terminal that performs heating by dissipating the heat medium, a heating outbound path for sending the heating medium from the tank to the heating terminal, and a heating return path for returning the heating medium from the heating terminal to the tank. In this heating apparatus, a heat pump or a fuel cell using carbon dioxide as a refrigerant can be adopted as a heat source device. In this case, it is preferable that the end portion connected to the tank for the return path for heat storage and the start end portion connected to the tank for the outbound path for heating are configured by a common pipe line. In addition, the common pipe line is always in conduction with the heat storage return path extending from the heat source unit and the heating forward path extending to the heating terminal. During simultaneous operation of the heat source unit and the heating terminal, (1) a common pipe from the tank with road and high temperature heat medium through forward for heating is sent to the heating terminal, all parts of the heating medium after the heat returned to the tank through the return heat storage from the heat source machines, joins directly to the heat medium flowing through the forward path for heating State, or (2) a part of the heated heating medium returned from the heat source device to the tank through the heat storage return path is sent to the tank through the common pipe, and the other part of the heating medium is heated. It is preferable that any one of the states sent directly to the outgoing route is set.

  In the conventional heating device, the heat medium that is heated by the heat source device and returned to the tank does not affect the temperature of the heat medium that is sent to the heating terminal. They were provided independently of each other. However, according to the study by the present inventors, the end portion connected to the tank of the return path for heat storage and the start end portion connected to the tank of the forward path for heating are configured by a common pipe, and the heat medium from the heat source machine is formed. It was found that the temperature fluctuation of the heat transfer medium sent to the heating terminal can be suppressed by directly joining the air to the heating outbound path. The reason is considered as follows.

  In the tank for storing the heat medium, temperature stratification is formed in the vertical direction, and the heating outward path for sending the heat medium to the heating terminal is usually connected to the upper part of the tank. If the amount of heat stored in the tank is sufficient, the temperature gradient (temperature difference in the vertical direction) of the heat medium at the top of the tank is relatively small. Therefore, even if the heat medium in the tank is shaken, the temperature of the heat medium flowing into the heating outbound path does not vary much. However, when the amount of heat stored in the tank decreases, the temperature gradient of the heat medium also increases in the upper part of the tank. At this time, if the heating operation by the heat source unit is performed and the heating medium in the tank shakes due to the inflow of the heating medium returned to the tank, the temperature of the heating medium flowing into the heating forward path may periodically fluctuate. become. That is, the temperature fluctuation of the heating medium sent to the heating terminal is caused by the shaking of the heating medium in the tank having a temperature gradient. In the sealed tank, the heat storage circulation path and the heating circulation Even if the paths are formed independently, it is virtually impossible to avoid the vibration generated in the heat medium.

  On the other hand, in the heating device of the present invention, the heat medium heated by the heat source unit is directly joined to the heating forward path. Therefore, even if the temperature of the heat medium flowing from the tank to the heating outbound path fluctuates due to the above-mentioned event, the heat sent to the heating terminal is joined by the heat medium heated by the heat source unit. The temperature of the medium will be stabilized.

  The heating apparatus according to the present invention may further include an auxiliary heat source device that is provided on the heating forward path and heats the heat medium sent to the heating terminal. According to this configuration, when the temperature of the heat medium sent to the heating terminal is too low, the temperature of the heat medium sent to the heating terminal can be increased by operating the auxiliary heat source machine. Even when the amount of heat is insufficient only by the heat storage capacity of the tank or the capacity of the heat source machine, the required heating can be performed by supplementing the shortage with the auxiliary heat source machine.

The figure which shows typically the structure of the hot-water supply heating system of an Example. The figure which shows the flow of the heat medium when heating while operating a heat pump unit. The figure which shows the flow of a heat medium when not heating a heat pump unit but heating only using a hot-water supply heating unit (auxiliary heat source machine). The figure which shows the flow of a heat medium when performing anti-freezing operation, while supply of snow-melting electric power is stopped. The heating apparatus of an Example WHEREIN: The graph which shows the result of having measured the temperature of the heat medium of each place. Graph A shows the measured temperature of the heat storage return thermistor 46, Graph B shows the measured temperature of the tank outlet thermistor 48, Graph C shows the measured temperature of the heating return thermistor 62, and Graph D shows the measured temperature of the heat storage forward thermistor 44. This is shown (the same applies to FIG. 6). The graph which shows the result of having measured the temperature of the heat medium of each place in the conventional heating apparatus.

  In one embodiment of the present invention, it is preferable to use water or antifreeze as the heating medium.

  In one embodiment of the present invention, it is preferable to employ a combustion device that burns fuel such as combustible gas as the auxiliary heat source unit.

  In one embodiment of the present invention, it is preferable to provide an anti-freezing pump for preventing the heat medium from freezing in the heat storage return path or the heat storage return path. In this case, it is preferable to provide a check valve in parallel with the antifreeze pump. According to this configuration, during operation of a heat source device such as a heat pump, the heat medium circulates through the check valve and the antifreeze pump is bypassed. be able to. On the other hand, when the antifreeze pump is operated, the inlet side and the outlet side of the antifreeze pump are blocked by the check valve, so that the heat medium can be reliably circulated between the tank and the heat source device without short-circuiting. .

  In one embodiment of the present invention, an expansion tank can be provided to absorb the thermal expansion of the heat medium after the circuit in which the heat medium circulates is a sealed circuit. In this case, the expansion tank is preferably provided with a first expansion tank according to the capacity of the tank and a second expansion tank according to the piping capacity at the installation site. According to this configuration, when the heating apparatus is installed, it is sufficient to calculate the required capacity of the expansion tank considering only the piping capacity at the installation site. Further, when the heating device is moved or the piping is changed, only the second expansion tank needs to be changed, and the first expansion tank can be used as it is.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a hot water supply / heating system 10 of the embodiment. As shown in FIG. 1, the hot water supply and heating system 10 includes a heat pump unit 20, a tank unit 28, a hot water supply and heating unit 80, and a heating terminal 90.

  The hot water supply and heating system 10 of the present embodiment is premised on use in a region where snow melting power (also simply referred to as snow melting power) can be used, such as the Hokkaido region. As is well known, the electric power for melting snow can be used for heating, but it is prohibited to use it for hot water supply. Therefore, in the hot water supply and heating system 10 of the present embodiment, the heat pump unit 20 and the tank unit 28 that are used only for heating use snow melting power, and the hot water supply and heating system 10 that is also used for hot water supply is a general light. It is configured to use electric power (also simply referred to as general electric power).

  The heat pump unit 20 is a heat pump that collects heat from the atmosphere and heats the heat medium sent from the tank unit 28. Although not shown, the heat pump unit 20 includes a compressor, a radiator, an expansion valve, an evaporator, and a refrigerant circulation path that connects them in order. In addition, a fan that blows air to the evaporator, a motor that drives the fan, and the like are also provided. The refrigerant circulation path is filled with carbon dioxide, which is a refrigerant. Since the details of the heat pump unit 20 are the same as known ones, the description thereof is omitted here. The heat pump unit 20 is provided with a circulation pump 22 that circulates the heat medium between the heat pump unit 20 and the tank unit 28.

  The tank unit 28 includes a tank 30 that stores a heat medium. The heat medium of the present embodiment is an antifreeze liquid. The tank 30 of this embodiment is an example, but has a capacity of 30 liters. A plurality of tank thermistors 42 are provided in the tank 30 along the height direction. The plurality of tank thermistors 42 are connected to the controller 54 of the tank unit 28. The controller 54 can grasp the amount of heat stored in the tank 30 from the temperatures detected by the plurality of tank thermistors 42.

  The tank 30 is connected to the heat pump unit 20 via a heat storage forward path 34 and a heat storage return path 32. The heat storage forward path 34 is a pipe line that sends a heat medium from the tank 30 to the heat pump unit 20, and is connected to the bottom of the tank 30. The heat storage return path 32 is a pipe line that returns the heat medium from the heat pump unit 20 to the tank 30, and is connected to the top of the tank 30. The heat storage outward path 34 and the heat storage return path 32 constitute a circulation path for circulating the heat medium between the heat pump unit 20 and the tank 30. The circulation pump 22 described above is provided in the circulation path. Although the circulation pump 22 of the present embodiment is built in the heat pump unit 20, the position of the circulation pump 22 is not particularly limited.

  A manual valve 24 and a heat storage outward thermistor 44 are provided in the heat storage outward path 34. Similarly, the heat storage return path 32 is also provided with a manual valve 24 and a heat storage return path thermistor 46. The heat storage outward thermistor 44 and the heat storage return thermistor 46 are connected to the controller 54 of the tank unit 28. The controller 54 grasps the temperature of the heat medium before heating by the heat pump unit 20 from the temperature detected by the heat storage forward path thermistor 44, and grasps the temperature of the heat medium after heating by the heat pump unit 20 from the temperature detected by the heat storage return path thermistor 46. can do.

  The heating terminal 90 performs heating by dissipating heat from the tank 30. The heating terminal 90 is, for example, a panel heater, a panel radiator, floor heating, a fan convector, or a hot water room air conditioner. The heating terminal 90 is connected to the tank 30 via the heating forward path 56 and the heating return path 60. The heating forward path 56 is a pipe line that sends a heat medium from the tank 30 to the heating terminal 90, and is connected to the top of the tank 30. The heating return path 60 is a conduit that returns the heat medium from the heating terminal 90 to the tank 30, and is connected to the bottom of the tank 30. The heating forward path 56 and the heating return path 60 constitute a circulation path for circulating the heat medium between the tank 30 and the heating terminal 90. Here, the start end portion 45 of the heating forward path 56 connected to the top of the tank 30 is also the end portion 45 of the heat storage return path 32 connected to the top of the tank 30, and both are constituted by a common pipe. The effect of this configuration will be described in detail later.

  A tank outlet thermistor 48 and a heating forward thermistor 58 are provided in the heating forward path 56. A heating return path thermistor 62 is provided in the heating return path 60. The tank outlet thermistor 48, the heating outward thermistor 58, and the heating return thermistor 62 are connected to the controller 54 of the tank unit 28. The controller 54 grasps the temperature of the heat medium flowing out from the tank 30 to the heating outward path 56 from the temperature detected by the tank outlet thermistor 48, and sends it to the heating terminal 90 through the heating outbound path 56 from the temperature detected by the heating outward path thermistor 58. The temperature of the heat medium to be obtained can be grasped, and the temperature of the heat medium after the heat radiation by the heating terminal 90 can be grasped from the temperature detected by the heating return path thermistor 62. A drain pipe 50 having a manual valve 52 is connected to the heating return path 60.

  The heating forward path 56 is connected to the heating terminal 90 via the hot water supply / heating unit 80. The hot water supply / heating unit 80 is a combustion-type heat source machine, and includes two burners 84 and 86 that combust combustible gas. One burner 84 is for hot water supply and heats the clean water flowing through the hot water supply pipe line 82. The other burner 86 is for heating, and heats the heat medium flowing through the heating forward path 56 as necessary. Thereby, the hot water supply and heating system 10 of the present embodiment can perform the required heating even when the amount of heat stored in the tank 30 is insufficient or when the operation of the heat pump unit 20 is impossible. The hot water supply / heating unit 80 has a controller 88. Further, the hot water supply / heating unit 80 is provided with a circulation pump 87 for circulating a heat medium between the heating terminal 90 and the tank unit 28. The position where the circulation pump 87 is provided is not limited to the hot water supply / heating unit 80 and is not particularly limited.

  The heating forward path 56 and the heating return path 60 are connected via a bypass path 64. Thereby, a part or all of the heat medium flowing in the heating return path 60 can be sent to the heating outbound path 56 without passing through the tank 30. A flow rate adjusting valve 66 is provided at a branch position between the heating return path 60 and the bypass path 64 so that the flow rate of the heat medium flowing through the bypass path 64 can be adjusted. The flow regulating valve 66 is connected to the controller 54, and its operation is controlled by the controller 54. According to this configuration, when the temperature of the heat medium sent to the heating terminal 90 through the heating forward path 56 is too high, the heat medium after the heat radiation flowing in the heating return path 60 is changed to the heat medium flowing in the heating forward path 56. By joining, the temperature of the heat medium sent to the heating terminal 90 can be lowered.

  FIG. 2 shows the flow of the heat medium when heating is performed while operating the heat pump unit 20. As shown in FIG. 2, a high-temperature heat medium is sent to the heating terminal 90 from the upper part of the tank 30 through the heating forward path 56. The high-temperature heat medium sent to the heating terminal 90 radiates heat at the heating terminal 90 and then returns to the lower part of the tank 30 through the heating return path 60. On the other hand, a low-temperature heat medium is sent to the heat pump unit 20 from the lower part of the tank 30 through the heat storage outbound path 34. The low-temperature heat medium sent to the heat pump unit 20 is heated in the heat pump unit 20 and then returned to the upper portion of the tank 30 through the heat storage return path 32. At this time, when the temperature of the heat medium sent to the heating terminal 90 is too low, auxiliary heating by the burner 86 of the hot water supply / heating unit 80 can be performed. Conversely, when the temperature of the heat medium is too high, the bypass path 64 is opened, and the low-temperature heat medium can be sent from the heating return path 60 to the heating outbound path 56.

  Here, as described above, the end portion 45 of the heat storage return path 32 connected to the top of the tank 30 and the start end portion 45 of the heating forward path 56 connected to the top of the tank 30 are configured by a common pipe. Yes. Therefore, a part or all of the heated heating medium sent from the heat pump unit 20 does not enter the tank 30 but directly joins the heating medium flowing in the heating forward path 56. According to this structure, as shown in FIG. 5, the temperature of the heat medium flowing through each pipe line is stabilized.

  On the other hand, FIG. 6 is a comparative example, and shows the measurement results of a product in which the common part is not provided in the heat storage return path 32 and the heating outward path 56, but both are provided independently of each other as in the conventional product. As is apparent from comparison between FIG. 5 and FIG. 6, in this embodiment, the temperature of the heat medium flowing through the heating forward path 56 is particularly stable (see graph B). If the heat source unit that heats the heat medium in the tank 30 is the heat pump unit 20 using carbon dioxide as a refrigerant, it is difficult to finely adjust the output (the amount of heating of the heat medium). Therefore, when the amount of heat stored in the tank 30 decreases, the temperature of the heat medium sent to the heating terminal 90 tends to become unstable. In order to avoid the temperature change of the heat medium, in the conventional product, the heat storage return path 32 and the heating outbound path 56 are made independent from each other, and the heat medium is temporarily transferred from the heat storage return path 32 to the heating outbound path 56 via the tank 30. I was sending. However, in the system of the present embodiment, a part of the heat storage return path 32 and part of the heating forward path 56 are intentionally shared, and the heating medium is directly merged from the heat storage return path 32 to the heating forward path 56, whereby the heating terminal 90. Succeeded in suppressing the temperature fluctuation of the heating medium sent to This technology can also be suitably employed in other heat source devices that are difficult to adjust output, such as systems that use fuel cells.

  FIG. 3 shows the flow of the heat medium when heating is performed using only the hot water supply / heating unit 80 without operating the heat pump unit 20. As shown in FIG. 3, the hot water supply and heating system 10 of the present embodiment can also perform heating only by the hot water supply and heating unit 80 without using the heat storage of the heat pump unit 20 and the tank 30. In this case, the heating forward path 56 and the heating return path 60 are connected by the bypass path 64, and the heat medium circulates without passing through the tank 30. Thereby, the load concerning the circulation pump 87 can be made small.

  As shown in FIG. 1, two expansion tanks 70 and 72 and a pressure relief valve 74 are provided in the heating forward path 56. In this embodiment, since the circuit through which the heat medium circulates is a closed circuit, two expansion tanks 70 and 72 are prepared to absorb the thermal expansion of the heat medium. The position where the two expansion tanks 70 and 72 are connected is not limited to the heating forward path 56, and may be connected to the heating return path 60 or another path, for example.

  The first expansion tank 70 is provided integrally with the tank unit 28. The first expansion tank 70 has a size corresponding to the tank 30. On the other hand, the second expansion tank 72 has a size corresponding to the piping capacity at the installation site. As described above, the two expansion tanks 70 and 72 are provided by being divided into an invariable part such as the capacity of the tank 30 and a changing part such as a pipe capacity that changes depending on the installation location. According to this configuration, when the hot water supply / heating system 10 is installed, it is sufficient to calculate only the required capacity of the second expansion tank 72 in consideration of only the piping capacity at the installation site. Also, when the hot water supply / heating system 10 is moved or the piping is changed, only the second expansion tank 72 may be changed, and the first expansion tank 70 can be used as it is.

  A freezing pump 38 and a check valve 40 are provided in the heat storage outward path 34. The antifreezing pump 38 and the check valve 40 are connected in parallel to each other. The antifreezing pump 38 is a pump for circulating the heat medium when the heat pump unit 20 is stopped, thereby preventing the heat medium from freezing. As is well known, a user of snow melting power must determine an energization cut-off time during which the use of snow melting power is stopped during a predetermined time period when the power demand reaches a peak. Since the heat pump unit 20 uses the snow melting power, it cannot be operated during the energization cut-off time. In the meantime, in the heat pump unit 20 disposed outdoors, the heat medium may freeze. Therefore, the freeze of the heat medium is prevented by operating the antifreeze pump 38 during the energization interruption time. The antifreezing pump 38 is connected to the controller 88 of the hot water supply / heating unit 80 by a power line 89. Thereby, it can operate | move even if the energization interruption | blocking time of snow-melting electric power receives supply of general lamp electric power.

  The antifreezing pump 38 only needs to circulate the heat medium to the extent that it can prevent freezing, and a relatively small pump can be employed. However, if the small antifreeze pump 38 is provided in the circulation path of the heat medium, the antifreeze pump 38 becomes a great resistance during the operation of the heat pump unit 20. Therefore, in this embodiment, the check valve 40 is provided in parallel with the antifreezing pump 38.

  According to the above configuration, when the heat pump unit 20 is operated, the heat medium circulates through the check valve 40 and the antifreeze pump 38 is bypassed as shown in FIG. No resistance due to 38. On the other hand, when the antifreeze pump 38 is operated, as shown in FIG. 4, the inlet side and the outlet side of the antifreeze pump 38 are blocked by the check valve 40, so that the tank 30 and the heat pump are not short-circuited in the closed circuit 36. A heat medium can be reliably circulated between the units 20. Instead of the check valve 40, an electromagnetic valve that closes when the antifreeze pump 38 is operated and opens when the heat pump unit 20 is operated may be provided.

  As mentioned above, although the Example of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

10: Hot water supply and heating system 20: Heat pump unit 28: Tank unit 30: Tank 32: Heat storage return path 34: Heat storage return path 38: Antifreeze pump 40: Check valve 45: End portion of the heat storage return path and the beginning of the heating output path Common pipe 56 also serving as a part: Outward heating path 60: Return path for heating 64: Bypass path 66: Flow rate adjusting valve 80: Hot water supply / heating unit 86: Burner 90: Heating terminal

Claims (2)

A tank for storing the heat medium,
A heat source machine for heating the heat medium;
A heat storage outbound path for sending the heat medium from the tank to the heat source machine,
A heat storage return path for returning the heat medium from the heat source machine to the tank;
A heating terminal that dissipates heat and heats the heating medium;
A heating outbound path for sending a heat medium from the tank to the heating terminal;
A heating return path for returning the heating medium from the heating terminal to the tank;
With
The heat source machine is either a heat pump using carbon dioxide as a refrigerant or a fuel cell,
The end part connected to the tank of the return path for heat storage and the start end part connected to the tank of the outbound path for heating are configured by a common pipe line,
The common pipe extending from the tank is always in conduction with the return path for heat storage extending from the heat source machine and the outbound path for heating extending to the heating terminal,
During simultaneous operation of the heat source machine and the heating terminal, (1) Heat is sent from the tank to the heating terminal through the common pipe line and the heating outgoing path, and is returned from the heat source machine to the tank through the heat storage return path. All parts of the heating medium of the later, the state that joins directly to the heat medium flowing through the forward path for heating, or (2) the tube portion of the heat medium after heating of the common returned to the tank through the return heat storage from the heat source equipment A heating apparatus that is sent to a tank through a path and is in one of the states in which another part of the heat medium is directly sent to a heating outbound path .   The heating apparatus according to claim 1, further comprising an auxiliary heat source device that is provided on the heating forward path and heats the heat medium sent to the heating terminal.

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