Heat transfer fluid circulation system and method for controlling the temperature of the heat transfer fluid

Abstract

This disclosure provides a heat transfer medium circulation system that can improve convenience by allowing the retrofitting of a heater to supplementally heat the heat transfer medium. [Solution] The heat transfer medium circulation system according to this disclosure comprises an outdoor unit that supplies a heated heat transfer medium, a heat utilization facility that utilizes the heat of the heat transfer medium supplied from the outdoor unit indoors, a heat transfer medium circulation pipe that circulates the heat transfer medium between the outdoor unit and the heat utilization facility, and an auxiliary heater attached to the outer circumference of the heat transfer medium circulation pipe in the portion of the heat transfer medium circulation pipe upstream of the heat utilization facility along the flow of the heat transfer medium.

Description

Technical Field

[0001] The present disclosure relates to a heat medium circulation system and a method for controlling the temperature of a heat medium.

Background Art

[0002] Patent Document 1 describes a hot water unit using a water-cooled medium heat exchanger in which a combustible refrigerant on the high-pressure side of a heat pump cycle and a heat medium flow through each other for heat exchange. In this hot water unit, a heater unit with a heater arranged inside a case forming a flow path of the heat medium is pre-installed. The heater unit is used to assist in heating the heat medium so that the heat medium reaches a predetermined temperature. For example, the heater unit is used when the heating capacity of the heat pump cycle decreases due to a decrease in the outside air temperature and the heat medium cannot be sufficiently heated by the heat radiation of the refrigerant in the water-cooled medium heat exchanger. Also, the heater unit can be used when the heat pump cycle fails.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a highly convenient heat medium circulation system that enables retrofitting of a heater even when a heater for assisting in heating the heat medium is not pre-installed in a heat medium circulation system that circulates a heat medium heated by an outdoor unit indoors.

Means for Solving the Problems

[0005] One embodiment of the heat transfer medium circulation system according to this disclosure includes: an outdoor unit that supplies a heated heat transfer medium; a heat utilization facility that utilizes the heat of the heat transfer medium supplied from the outdoor unit indoors; a heat transfer medium circulation pipe that circulates the heat transfer medium between the outdoor unit and the heat utilization facility; and an auxiliary heater attached to the outer circumference of the heat transfer medium circulation pipe in the portion of the heat transfer medium circulation pipe upstream of the heat utilization facility along the flow of the heat transfer medium.

[0006] One embodiment of the heat transfer medium temperature control method according to the present disclosure is a heat transfer medium temperature control method executed by a heater control device of a heat transfer medium circulation system comprising: an outdoor unit that supplies a heated heat transfer medium; a heat utilization facility that utilizes the heat of the heat transfer medium supplied from the outdoor unit indoors; a heat transfer medium circulation pipe that circulates the heat transfer medium between the outdoor unit and the heat utilization facility; an auxiliary heater attached to the outer circumference of the heat transfer medium circulation pipe in the portion of the heat transfer medium circulation pipe upstream of the heat utilization facility along the flow of the heat transfer medium; an auxiliary temperature sensor attached to the outer circumference of the heat transfer medium circulation pipe in the portion of the heat transfer medium circulation pipe between the auxiliary heater and the heat utilization facility; and an outlet temperature sensor provided on the outdoor unit that measures the temperature of the heat transfer medium flowing out into the heat transfer medium circulation pipe, wherein the heater control device controls the supply of power to the auxiliary heater using the higher of the detected temperature detected by the auxiliary temperature sensor and the detected temperature detected by the outlet temperature sensor. [Effects of the Invention]

[0007] According to this disclosure, even when a heater for supplementary heating of the heat transfer medium is not pre-installed, it is possible to provide a highly convenient heat transfer medium circulation system by allowing the heater to be added later. [Brief explanation of the drawing]

[0008] [Figure 1] Diagram showing the configuration of the heat transfer medium circulation system in the embodiment. [Figure 2] This figure shows an example of how auxiliary heaters and auxiliary temperature sensors are installed in the heat transfer medium circulation piping. [Figure 3]A diagram showing an example of the configuration of an auxiliary heater. [Figure 4] A diagram showing an example of the configuration of an auxiliary temperature sensor. [Figure 5] A diagram showing an example of the configuration of a heater control device. [Figure 6] A flowchart illustrating the operation procedure of a heat transfer fluid circulation system. [Modes for carrying out the invention]

[0009] (Knowledge and other information that formed the basis of this disclosure) At the time the inventors conceived of this disclosure, there was a technology that, in a hot water unit equipped with a water-refrigerant heat exchanger that heats the heat transfer medium with a flammable refrigerant of the heat pump cycle, had a heater section pre-installed in a case that formed a flow path for the heat transfer medium, and when the heating capacity of the heat pump cycle decreased, the heater section would heat the heat transfer medium to a predetermined temperature.

[0010] However, the inventors discovered that the above-mentioned conventional technology does not provide a means for adding an auxiliary heater to a hot water unit that does not have a heater unit pre-installed, and that there is room for improvement in terms of expandability and convenience. To solve this problem, the subject matter of this disclosure was established. Therefore, this disclosure provides a heat transfer medium circulation system that offers high expandability and convenience by enabling the retrofitting of a heater to supplementally heat the heat transfer medium.

[0011] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art. The attached drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0012] (Embodiment) Hereinafter, embodiments will be described with reference to the drawings. [1. Configuration of Heat Medium Circulation System] FIG. 1 is a diagram showing an example of the configuration of a heat medium circulation system 1 according to an embodiment. The heat medium circulation system 1 includes an outdoor unit 2 that supplies a warmed heat medium, a heat utilization facility 3 that utilizes the heat of the heat medium supplied from the outdoor unit 2 in an indoor space S, and a heat medium circulation pipe 4 that circulates the heat medium between the outdoor unit 2 and the heat utilization facility 3.

[0013] The heat utilization facility 3 is an arbitrary facility that utilizes the heat of the heat medium from the outdoor unit 2. For example, it can be a water heater that provides hot water warmed by the heat of the heat medium, a heater that warms the indoor space S with the heat of the heat medium, or a floor heating panel that warms the floor of the indoor space S.

[0014] The outdoor unit 2 is arranged outside a building H such as a dwelling having an indoor space S where the heat utilization facility 3 is arranged. The outdoor unit 2 has a compressor 21 that compresses a refrigerant and discharges a high-temperature refrigerant, and a pressure reducing device 22 that reduces the pressure of the refrigerant. The pressure reducing device 22 is, for example, an electromagnetic expansion valve.

[0015] Further, the outdoor unit 2 has an evaporator 23 that performs heat exchange between air and the refrigerant, a four-way valve 24 that changes the flow path of the refrigerant, and a water-cooled heat exchanger 25 that performs heat exchange between the heat medium and the high-temperature refrigerant to generate a high-temperature heat medium. The outdoor unit 2 is also provided with a blower fan 26 that blows air to the evaporator 23 to promote heat exchange between the air and the refrigerant.

[0016] The compressor 21, the pressure reducing device 22, the evaporator 23, the four-way valve 24, and the water-cooled heat exchanger 25 are annularly connected by a refrigerant pipe 20a to form a heat pump cycle.

[0017] The heat medium circulation pipe 4 is connected to the heat medium pipe 20b inside the outdoor unit 2 by an outlet connector 27a and an inlet connector 27b provided on the outdoor unit 2. In the water-cooled medium heat exchanger 25, the high-temperature refrigerant in the refrigerant pipe 20a that constitutes the heat pump cycle and the heat medium in the heat medium pipe 20b connected to the heat medium circulation pipe 4 flow past each other for heat exchange, and the heat medium heated by the heat of the high-temperature refrigerant is supplied to the heat utilization equipment 3 through the heat medium circulation pipe 4. Here, for example, water or antifreeze can be used as the heat medium.

[0018] In the water-cooled medium heat exchanger 25, the high-temperature refrigerant in the refrigerant pipe that constitutes the heat pump cycle and the heat medium in the heat medium circulation pipe 4 flow past each other for heat exchange, and the heat medium heated by the heat of the high-temperature refrigerant is supplied to the heat utilization equipment 3 through the heat medium circulation pipe 4. Here, for example, water or antifreeze can be used as the heat medium.

[0019] The heat medium flows through the heat medium circulation pipe 4 from the water-cooled medium heat exchanger 25 toward the heat utilization equipment 3 via the outlet connector 27a, enters the outdoor unit 2 from the inlet connector 27b after passing through the heat utilization equipment 3, and returns to the water-cooled medium heat exchanger 25.

[0020] In the portion of the heat medium pipe 20b that is connected to the outlet connector 27a, an outlet temperature sensor 28a for measuring the outlet temperature, which is the temperature of the heat medium flowing out from the outlet connector 27a to the outside of the outdoor unit 2, is provided. Also, in the portion of the heat medium pipe 20b that is connected to the water-cooled medium heat exchanger 25 inside the outdoor unit 2 from the inlet connector 27b, an inlet temperature sensor 28b for measuring the temperature of the heat medium flowing back from the inlet connector 27b to the inside of the outdoor unit 2 is provided.

[0021] The outdoor unit 2 also includes a control device 29. The control device 29 is, for example, a computer including a processor and a memory, and operates by executing a program stored in the memory. The control device 29 controls the operations of the compressor 21, the decompression device 22, and the four-way valve 24 that constitute the heat pump cycle in the outdoor unit 2, as well as the operation of the blower fan 26. Hereinafter, the operations of the compressor 21, the decompression device 22, and the four-way valve 24, as well as the control operation of the blower fan 26, are referred to as heat pump cycle control.

[0022] In this embodiment, the heat transfer medium circulation system 1 is equipped with an auxiliary heater 5 attached to the outer circumference of the heat transfer medium circulation pipe 4 in the portion of the heat transfer medium circulation pipe 4 upstream of the heat utilization equipment 3, along the flow of the heat transfer medium. As a result, in the heat transfer medium circulation system 1, even if a heater section that provides auxiliary heating of the heat transfer medium is not pre-installed in the case that forms the flow path of the heat transfer medium as in conventional systems, the auxiliary heater 5 can be attached to the outer circumference of the heat transfer medium circulation piping 4 after the heat transfer medium circulation system 1 has been installed. Therefore, the heat transfer medium circulation system 1 can be expanded and made more convenient by allowing the auxiliary heater 5 to be added later.

[0023] The heat transfer medium circulation system 1 also has an auxiliary temperature sensor 6 attached to the outer circumference of the heat transfer medium circulation pipe 4 in the portion of the heat transfer medium circulation pipe 4 between the auxiliary heater 5 and the heat utilization equipment 3. The auxiliary temperature sensor 6 detects the temperature of the heat transfer medium flowing inside the heat transfer medium circulation pipe 4 through the pipe wall of the heat transfer medium circulation pipe 4.

[0024] As a result, in the heat transfer medium circulation system 1, an auxiliary temperature sensor 6, which can be used to control the energization of the auxiliary heater 5, can be retrofitted to the outer circumference of the heat transfer medium circulation piping 4 together with the auxiliary heater 5 after the heat transfer medium circulation system 1 has been installed, thereby enabling proper control of the energization of the auxiliary heater 5.

[0025] Figure 2 shows an example of how the auxiliary heater 5 and auxiliary temperature sensor 6 are mounted on the heat transfer medium circulation pipe 4. The auxiliary heater 5 and auxiliary temperature sensor 6 can be configured, for example, as cylindrical components mounted on the outer circumference of the heat transfer medium circulation pipe 4.

[0026] Figure 3 is a cross-sectional view taken along the line III-III in Figure 2, and shows an example of the configuration of the auxiliary heater 5. The auxiliary heater 5 includes, for example, a sheet-shaped heater 5a that covers the outer circumference of the heat transfer medium circulation pipe 4, and a cylindrical heat insulating cover 5b that covers the outer circumference of the sheet-shaped heater 5a. The sheet-shaped heater 5a is constructed, for example, by sandwiching an electric heating wire between two resin films. The heat insulating cover 5b is composed of, for example, two heat insulating members 50 having a shape that divides a cylinder into two equal parts along its central axis. The two heat insulating members 50 can be stably maintained on the outer circumference of the heat transfer medium circulation pipe 4 by, for example, press-fitting recesses and protrusions provided on surfaces that face each other when installed.

[0027] Figure 4 is a cross-sectional view taken along the line IV-IV in Figure 2, and shows an example of the configuration of the auxiliary temperature sensor 6. The auxiliary temperature sensor 6 includes, for example, a sheet-shaped temperature sensor 6a placed on a part of the outer circumference of the heat transfer medium circulation pipe 4, and a cylindrical heat insulating cover 6b that covers the outer circumference of the sheet-shaped temperature sensor 6a. The sheet-shaped temperature sensor 6a is constructed by sandwiching a temperature sensing element such as a thermocouple or thermistor between two resin films. The heat insulating cover 6b is composed of, for example, two heat insulating members 60 and 61 having a shape that divides a cylinder into two equal parts along its central axis. One of the heat insulating members 60 has a recess on its inner surface for housing the sheet-shaped temperature sensor 6a. The two heat insulating members 60 and 61 stably maintain the sheet-shaped temperature sensor 6a placed on the outer circumference of the heat transfer medium circulation pipe 4 by, for example, press-fitting recesses and protrusions provided on surfaces that face each other when installed.

[0028] Referring to Figure 1, the heat transfer medium circulation system 1 may also include a remote control 8 operated by the user, a heater control device 7 that controls the operation of the auxiliary heater 5, and a server 9 that the heater control device 7 can communicate with via a communication network NW such as the Internet.

[0029] The heater control device 7 may be installed, for example, together with the auxiliary heater 5 and the auxiliary temperature sensor 6 in the piping area PA within the building H where the heat transfer medium circulation piping 4 is laid.

[0030] The remote control 8 is connected to the control unit 29 and heater control unit 7 of the outdoor unit 2 in a communication manner. The remote control 8 transmits operation and setting instructions to the control unit 29 and heater control unit 7 according to user input. For example, the remote control 8 transmits the target temperature of the heat transfer medium, which is the target temperature of the heat transfer medium supplied to the heat utilization equipment 3, to the control unit 29 and heater control unit 7 according to user input. The remote control 8 also receives and displays information about the operation and status of the outdoor unit 2 from the control unit 29 and receives and displays information from the heater control unit 7.

[0031] The control device 29 receives the target temperature of the heat transfer medium from the remote control 8 and calculates a target value for the outlet temperature, which is the temperature of the heat transfer medium discharged from the outlet connector 27a. In calculating the target value for the outlet temperature, the control device 29 may consider the heat loss of the heat transfer medium in the section from the outlet connector 27a through the heat transfer medium circulation pipe 4 to the heat utilization equipment 3. Based on the inlet temperature, which is the temperature of the heat transfer medium passing through the inlet connector 27b detected by the inlet temperature sensor 28b, the control device 29 performs heat pump cycle control so that the outlet temperature becomes the calculated target value. The heat loss may be input to the control device 29 via the remote control 8 when the outdoor unit 2 is installed and stored in the control device 29.

[0032] The control device 29 also sends a non-reach notification to the heater control device 7 if, as a result of executing the heat pump cycle control described above, the temperature detected by the outlet temperature sensor 28a does not reach the target value calculated above. The control device 29 also transmits the operation information of the outdoor unit 2, including the temperature detected by the outlet temperature sensor 28a and the temperature detected by the inlet temperature sensor, to the heater control device 7 at predetermined time intervals.

[0033] When the heater control device 7 receives the above-mentioned non-delivery notification from the control device 29, it controls the operation of the auxiliary heater 5 based on the target temperature of the heat transfer medium received from the remote control 8. The heater control device 7 also transmits the operation information of the outdoor unit 2, the energized current of the auxiliary heater 5, and the temperature detected by the auxiliary temperature sensor 6, received from the control device 29, to the server 9 at predetermined time intervals. The server 9 receives this information, stores the received information as the operation history of the heat transfer medium circulation system 1, and manages the operation of the heat transfer medium circulation system 1.

[0034] [2. Heater control device configuration] Figure 5 shows an example of the configuration of the heater control device 7. The heater control device 7 is a computer comprising a processor 70 such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit), memory 71, and a communication device 72. The communication device 72 is a transceiver for communicating with the control device 29, remote control 8, and server 9 provided by the outdoor unit 2.

[0035] The memory 71 is composed of a magnetic memory device, a semiconductor memory element such as flash ROM (Read Only Memory), and / or other types of non-volatile memory devices. The memory 71 may also include RAM (Random Access Memory) which constitutes the work area of ​​the processor 70.

[0036] The processor 70 includes, as functional elements or functional units, an operation control unit 74 and an information acquisition unit 75. These functional elements of the processor 70 are realized, for example, by the processor 70 of the heater control device 7, which is a computer, reading and executing a program 73 stored in memory 71. The program 73 can be stored in any storage medium that is readable by a computer. Alternatively, all or part of the functional elements of the processor 70 can be configured by hardware, each including one or more electronic circuit components.

[0037] The operation control unit 74 receives the target temperature of the heat transfer medium supplied to the heat utilization equipment 3 from the remote control 8. Based on the target temperature of the heat transfer medium, the operation control unit 74 controls the operation of the auxiliary heater 5. When the operation control unit 74 receives a non-reach notification from the control device 29 of the outdoor unit 2 indicating that the temperature detected by the outlet temperature sensor 28a did not reach the target value even after heat pump cycle control, the operation control unit 74 starts controlling the operation of the auxiliary heater 5 in order to perform auxiliary heating of the heat transfer medium by the auxiliary heater 5. Hereinafter, the control of the operation of the auxiliary heater 5 for the above auxiliary heating will be referred to as auxiliary heating control.

[0038] In this embodiment, the operation control unit 74 controls the power supply to the auxiliary heater 5 using the higher of the detected temperature detected by the auxiliary temperature sensor 6 and the detected temperature detected by the outlet temperature sensor 28a of the outdoor unit 2.

[0039] As a result, when the temperature detected by the auxiliary temperature sensor 6 is higher than the temperature detected by the outlet temperature sensor 28a, that is, when the auxiliary temperature sensor 6 appropriately detects the temperature of the heat transfer medium in the heat transfer medium circulation pipe 4 heated by the auxiliary heater 5, the auxiliary heater can be precisely controlled based on the temperature detected by the auxiliary temperature sensor 6 so that the temperature of the heat transfer medium flowing into the heat utilization equipment 3 reaches the target temperature of the heat transfer medium. On the other hand, if the temperature detected by the auxiliary temperature sensor 6 is lower than the temperature detected by the outlet temperature sensor 28a, that is, if the temperature detected by the auxiliary temperature sensor 6 deviates from the temperature of the heat medium passing through the heat medium circulation pipe 4 and becomes low due to an abnormality in the mounting condition of the auxiliary temperature sensor 6 to the heat medium circulation pipe 4, the auxiliary heater 5 can be controlled based on the temperature detected by the outlet temperature sensor 28a so that the temperature of the heat medium flowing into the heat utilization equipment 3 reaches the target temperature of the heat medium.

[0040] The discrepancy between the temperature detected by the auxiliary temperature sensor 6 and the temperature of the heat transfer medium in the heat transfer medium circulation pipe 4, as described above, can occur, for example, due to an abnormality in the mounting of the auxiliary temperature sensor 6 to the heat transfer medium circulation pipe 4, or due to a low thermal conductivity of the pipe wall of the heat transfer medium circulation pipe 4. Furthermore, an abnormality in the mounting of the auxiliary temperature sensor 6 could occur, for example, if the auxiliary temperature sensor 6 is mounted in a position where it is floating away from the outer surface of the heat transfer medium circulation pipe 4, or if the auxiliary temperature sensor 6 is not properly sealed to the heat transfer medium circulation pipe 4.

[0041] Specifically, the operation control unit 74 may operate as follows, for example. First, at the start of auxiliary heating control, the temperature of the heat transfer medium at the auxiliary heater 5 is lower than the temperature at the outlet connector 27a due to heat loss as it flows through the heat transfer medium circulation pipe 4 from the outlet connector 27a to the auxiliary heater 5. Therefore, the temperature detected by the outlet temperature sensor 28a is higher than the temperature detected by the auxiliary temperature sensor 6. For this reason, the operation control unit 74 uses the temperature detected by the outlet temperature sensor 28a to perform feedforward control of the power supply to the auxiliary heater 5.

[0042] In feedforward control, for example, the operation control unit 74 controls the power supply to the auxiliary heater 5 so that the auxiliary heater 5 generates a target amount of heat, which is the amount of heat required to raise the temperature of the heat medium from the temperature detected by the outlet temperature sensor 28a to the target temperature of the heat medium, plus the amount of heat to compensate for the heat loss of the heat medium in the section from the outlet connector 27a through the heat medium circulation pipe 4 to the heat utilization equipment 3. The heat loss mentioned above can be input to the heater control device 7 via the remote control 8 when the outdoor unit 2 is installed and stored in the memory 71.

[0043] Subsequently, when the auxiliary heater 5 is energized, the temperature of the heat transfer medium passing through the auxiliary heater 5 rises, and when the temperature detected by the auxiliary temperature sensor 6 becomes higher than the temperature detected by the outlet temperature sensor 28a, the operation control unit 74 uses the temperature detected by the auxiliary temperature sensor 6, which is downstream of the auxiliary heater 5 along the flow of the heat transfer medium, to provide feedback control to the energization of the auxiliary heater 5.

[0044] In feedback control, for example, the operation control unit 74 controls the power supply to the auxiliary heater 5 so that the auxiliary heater 5 generates a target amount of heat, which is the amount of heat required to raise the temperature of the heat medium from the temperature detected by the auxiliary temperature sensor 6 to the target temperature of the heat medium, plus the amount of heat to compensate for the heat loss of the heat medium in the section from the auxiliary heater 5 through the heat medium circulation pipe 4 to the heat utilization equipment 3. The above value of heat loss can be input to the heater control device 7 via the remote control 8 and stored in the memory 71 when the auxiliary heater 5 is installed in the heat medium circulation pipe 4.

[0045] However, if the temperature detected by the auxiliary temperature sensor 6 does not exceed the temperature detected by the outlet temperature sensor 28a even after power is supplied to the auxiliary heater 5, the operation control unit 74 continues the feedforward control described above using the temperature detected by the outlet temperature sensor 28a, which is higher than the temperature detected by the auxiliary temperature sensor 6.

[0046] The operation control unit 74 also detects whether the connection to the auxiliary temperature sensor 6 is good or not, and if the connection to the auxiliary temperature sensor 6 is poor, it controls the power supply to the auxiliary heater 5 using the detected temperature detected by the outlet temperature sensor 28a. For example, the operation control unit 74 may determine that the connection to the auxiliary temperature sensor 6 is poor if the detection signal or detection data input from the terminal for connection to the auxiliary temperature sensor 6 provided on the heater control device 7 indicates a temperature within the appropriate detection temperature range. Also, for example, the operation control unit 74 may determine that the connection to the auxiliary temperature sensor 6 is poor if the detection signal or detection data input from the terminal for connection to the auxiliary temperature sensor 6 provided on the heater control device 7 corresponds to an open state of the terminal (nothing is connected) or a short state between the terminals (short between terminals), or if it indicates a temperature that is more than a predetermined value outside the appropriate detection temperature range. Here, a poor connection to the auxiliary temperature sensor 6 may include the auxiliary temperature sensor 6 not being connected to the heater control device 7.

[0047] As a result, in the heat transfer medium circulation system 1, even if the auxiliary temperature sensor 6 is not attached to the heat transfer medium circulation pipe 4, or if the auxiliary temperature sensor 6 is not properly connected to the heater control device 7, the heat transfer medium can be heated by the auxiliary heater 5.

[0048] The information gathering unit 75 transmits the operation information of the outdoor unit 2, the energized current of the auxiliary heater 5, and the temperature detected by the auxiliary temperature sensor 6, received from the control device 29, to the server 9 at predetermined time intervals. In this embodiment, in particular, when the operation control unit 74 detects a connection failure with the auxiliary temperature sensor 6, the information gathering unit 75 notifies the user of the connection failure with the auxiliary temperature sensor via the remote control 8 and also notifies the server 9 of the connection failure. As a result, in the heat transfer fluid circulation system 1, for example, if a connection problem with the auxiliary temperature sensor 6 is detected during the trial run when the heat transfer fluid circulation system 1 is installed, the remote control 8 will notify the server 9, allowing for quick action to be taken if the auxiliary temperature sensor 6 is not attached to the heat transfer fluid circulation piping 4 or if there is an abnormality in the attachment of the auxiliary temperature sensor 6.

[0049] [3. Operation] Next, the operation of the heat transfer medium circulation system 1 will be described. Figure 6 is a flowchart showing the processing procedure for controlling the temperature of the heat transfer medium, performed by the computer in the heat transfer medium circulation system 1. Here, the computer in the heat transfer medium circulation system 1, in this embodiment, is the control device 29 and the heater control device 7 of the outdoor unit 2. The process shown in Figure 6 starts when the power to the outdoor unit 2 and the heater control device 7 is turned on.

[0050] When processing begins, the control device 29 of the outdoor unit 2 first determines whether or not it has received an operation start command from the remote control 8 (S100). The operation start command is transmitted from the remote control 8 to the control device 29 in response to the user performing an operation start operation on the remote control 8.

[0051] If the control unit 29 has not received an operation start instruction from the remote control 8 (S100, NO), it returns to step S100 and repeats the process, waiting to receive an operation start instruction from the remote control 8. On the other hand, if the control unit 29 has received an operation start instruction from the remote control 8 (S100, YES), the control unit 29 and the heater control unit 7 receive the target temperature of the heat transfer medium, which is the target temperature of the heat transfer medium to be supplied to the heat utilization equipment 3, from the remote control 8 (S102). The target temperature of the heat transfer medium is input to the remote control 8, for example, by user operation, and is transmitted from the remote control 8 to the control unit 29 and the heater control unit 7 following the operation start instruction.

[0052] Next, the control device 29 calculates a target value for the outlet temperature, which is the temperature of the heat medium to be discharged from the outlet connector 27a, based on the received target temperature of the heat medium (S104). As described above, when calculating the target value, the heat loss of the heat medium in the section from the outlet connector 27a through the heat medium circulation pipe 4 to the heat utilization equipment 3 may be taken into consideration.

[0053] Next, the control device 29 starts heat pump cycle control (S106) based on the inlet temperature, which is the temperature of the heat transfer medium passing through the inlet connector 27b detected by the inlet temperature sensor 28b, so that the outlet temperature becomes the calculated target value.

[0054] Next, the control device 29 determines whether or not it has received a stop command from the remote control 8 (S108). A stop command may be transmitted from the remote control 8 to the control device 29 and the heater control device 7 in response to the user performing a stop operation on the remote control 8.

[0055] Then, when the control device 29 receives a stop command from the remote control 8 (S108, YES), the control device 29 terminates this process. On the other hand, when the control device 29 does not receive a stop command from the remote control 8 (S108, NO), the control device 29 determines whether the outlet temperature has reached the target value calculated in step S104 within a predetermined time from the start of the heat pump cycle control in step S106 (S110). The predetermined time can be set, for example, according to a predetermined calculation formula, with the time becoming longer the greater the temperature difference between the inlet temperature at the start of the heat pump cycle control and the target value.

[0056] Then, if the outlet temperature reaches the target value within a predetermined time (S110, YES), the control device 29 returns to step S106 and continues the heat pump cycle control. On the other hand, if the outlet temperature does not reach the target value within a predetermined time (S110, NO), the control device 29 sends a non-reach notification to the heater control device 7. In response to receiving the non-reach notification from the control device 29, the heater control device 7 starts auxiliary heating control, which is the process from step S112 to step S120.

[0057] In auxiliary heating control, the operation control unit 74 of the heater control device 7 first determines whether the connection between the heater control device 7 and the auxiliary temperature sensor 6 is good (S112). If the connection between the heater control device 7 and the auxiliary temperature sensor 6 is good (S112, YES), the operation control unit 74 then determines whether the temperature detected by the auxiliary temperature sensor 6 is equal to or greater than the temperature detected by the outlet temperature sensor 28a (S114).

[0058] Then, when the temperature detected by the auxiliary temperature sensor 6 is equal to or greater than the temperature detected by the outlet temperature sensor 28a (S114, YES), the operation control unit 74 controls the power supply to the auxiliary heater 5 based on the temperature detected by the auxiliary temperature sensor 6 (S116). Specifically, the operation control unit 74 controls the power supply to the auxiliary heater 5 by the feedback control described above.

[0059] Next, the operation control unit 74 determines whether or not it has received a stop command from the remote control 8 (S122). As described above, a stop command may be transmitted from the remote control 8 to the control unit 29 and the heater control unit 7 in response to the user performing a stop operation on the remote control 8.

[0060] Then, when the remote control 8 receives a stop command (S122, YES), the operation control unit 74 terminates this process. On the other hand, when the remote control 8 does not receive a stop command (S122, NO), the operation control unit 74 returns to step S112 and repeats the auxiliary heating control.

[0061] On the other hand, in step S114, if the temperature detected by the outlet temperature sensor 28a is higher than the temperature detected by the auxiliary temperature sensor 6, that is, if the temperature detected by the auxiliary temperature sensor 6 is lower than the temperature detected by the outlet temperature sensor 28a (S114, NO), the operation control unit 74 controls the power supply to the auxiliary heater 5 based on the temperature detected by the outlet temperature sensor 28a (S120). Specifically, the operation control unit 74 controls the power supply to the auxiliary heater 5 by the feedforward control described above. After that, the operation control unit 74 moves on to step S122.

[0062] On the other hand, if the connection between the heater control device 7 and the auxiliary temperature sensor 6 is faulty in step S112 (S112, NO), the information gathering unit 75 notifies the user of the faulty connection with the auxiliary temperature sensor via the remote control 8 and also notifies the server 9 of the faulty connection (S118). Subsequently, the operation control unit 74 moves to step S120 to control the power supply to the auxiliary heater 5 based on the temperature detected by the outlet temperature sensor 28a.

[0063] [1-3. Effects, etc.] As described above, the heat transfer medium circulation system 1 of this embodiment includes an outdoor unit 2 that supplies a heated heat transfer medium, a heat utilization device 3 that utilizes the heat of the heat transfer medium supplied from the outdoor unit 2 inside the room, and a heat transfer medium circulation pipe 4 that circulates the heat transfer medium between the outdoor unit 2 and the heat utilization device 3. Furthermore, the heat transfer medium circulation system 1 includes an auxiliary heater 5 attached to the outer circumference of the heat transfer medium circulation pipe 4 in the portion upstream of the heat utilization device 3 along the flow of the heat transfer medium. As a result, even if a heater for supplementally heating the heat transfer medium supplied from the outdoor unit 2 to the indoor unit is not pre-installed in the heat transfer medium circulation system 1, the auxiliary heater 5 can be attached to the outer circumference of the heat transfer medium circulation piping 4 after the heat transfer medium circulation system 1 is installed. This makes it possible to add the auxiliary heater 5 later, thereby improving the expandability and convenience of the heat transfer medium circulation system 1.

[0064] Furthermore, the heat transfer medium circulation system 1 of this embodiment further includes a heater control device 7 that controls the operation of the auxiliary heater 5, an auxiliary temperature sensor 6 attached to the outer circumference of the heat transfer medium circulation pipe 4 in the portion of the heat transfer medium circulation pipe 4 between the auxiliary heater 5 and the heat utilization equipment 3, and an outlet temperature sensor 28a provided on the outdoor unit 2 that measures the temperature of the heat transfer medium flowing out into the heat transfer medium circulation pipe 4. The heater control device 7 controls the supply of power to the auxiliary heater 5 using the higher of the detected temperature detected by the auxiliary temperature sensor 6 and the detected temperature detected by the outlet temperature sensor 28a. According to this, if the temperature detected by the auxiliary temperature sensor 6 is higher than the temperature detected by the outlet temperature sensor 28a, that is, if the auxiliary temperature sensor 6 appropriately detects the temperature of the heat medium in the heat medium circulation pipe 4 heated by the auxiliary heater 5, the auxiliary heater can be accurately controlled based on the temperature detected by the auxiliary temperature sensor 6 so that the temperature of the heat medium flowing into the heat utilization equipment 3 reaches the target temperature. On the other hand, if the temperature detected by the auxiliary temperature sensor 6 is lower than the temperature detected by the outlet temperature sensor 28a, that is, if the temperature detected by the auxiliary temperature sensor 6 deviates significantly from the temperature of the heat medium passing through the heat medium circulation pipe 4 due to an abnormality in the mounting condition of the auxiliary temperature sensor 6 to the heat medium circulation pipe 4, the auxiliary heater can be controlled based on the temperature detected by the outlet temperature sensor 28a so that the temperature of the heat medium flowing into the heat utilization equipment 3 reaches the target temperature.

[0065] Furthermore, according to this embodiment, the heater control device 7 detects whether the connection with the auxiliary temperature sensor 6 is good or not, and if the connection with the auxiliary temperature sensor 6 is poor, it controls the power supply to the auxiliary heater 5 using the temperature detected by the outlet temperature sensor 28a. This allows the auxiliary heater 5 to heat the heat transfer medium even if the auxiliary temperature sensor 6 is not attached to the heat transfer medium circulation pipe 4 or if the auxiliary temperature sensor 6 is not properly connected to the heater control device 7.

[0066] Furthermore, the heat transfer medium circulation system 1 of this embodiment further includes a remote control 8 that gives operation instructions to the outdoor unit 2, and a server 9. When the heater control device 7 detects a poor connection with the auxiliary temperature sensor 6, it notifies the user of the poor connection with the auxiliary temperature sensor 6 via the remote control 8 and also notifies the server 9 of the poor connection. As a result, for example, if a connection problem with the auxiliary temperature sensor 6 is detected during the trial run when the heat transfer fluid circulation system 1 is installed, it will be notified via the remote control 8 and the server 9 will be notified, allowing for quick action to be taken in cases such as forgetting to attach the auxiliary temperature sensor 6 to the heat transfer fluid circulation piping 4 or abnormalities in the attachment of the auxiliary temperature sensor 6.

[0067] Furthermore, the heat transfer medium temperature control method performed by the heat transfer medium circulation system 1 of this embodiment includes the heater control device 7 controlling the supply of power to the auxiliary heater 5 using the higher of the detected temperature detected by the auxiliary temperature sensor 6 and the detected temperature detected by the outlet temperature sensor 28a. According to this, it is possible to retrofit the auxiliary heater 5 and auxiliary temperature sensor 6 after the installation of the heat transfer medium circulation system 1, and to appropriately control the auxiliary heater by using the auxiliary temperature sensor 6 and the outlet temperature sensor 28a in accordance with the detection state of the heat transfer medium temperature by the auxiliary temperature sensor 6.

[0068] As described above, embodiments have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these embodiments and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to combine the elements described in the above embodiments to create new embodiments. Since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents.

[0069] (Note) Based on the above description of embodiments, the following technologies are disclosed.

[0070] (Technical 1) A heat transfer medium circulation system comprising: an outdoor unit that supplies a heated heat transfer medium; a heat utilization device that utilizes the heat of the heat transfer medium supplied from the outdoor unit indoors; a heat transfer medium circulation pipe that circulates the heat transfer medium between the outdoor unit and the heat utilization device; and an auxiliary heater attached to the outer circumference of the heat transfer medium circulation pipe in the portion of the heat transfer medium circulation pipe upstream of the heat utilization device along the flow of the heat transfer medium. According to this, even in the case of a heat transfer medium circulation system that does not have a heater pre-installed to supplementally heat the heat transfer medium supplied from the outdoor unit to the indoor unit, the supplement heater can be attached to the outer circumference of the heat transfer medium circulation piping after the heat transfer medium circulation system has been installed. This makes it possible to add the supplement heater later, thereby improving the expandability and convenience of the heat transfer medium circulation system.

[0071] (Technology 2) The heat transfer medium circulation system according to Technology 1, comprising: a heater control device for controlling the operation of the auxiliary heater; an auxiliary temperature sensor attached to the outer circumference of the heat transfer medium circulation piping in the portion of the heat transfer medium circulation piping between the auxiliary heater and the heat utilization equipment; and an outlet temperature sensor provided on the outdoor unit for measuring the temperature of the heat transfer medium flowing out into the heat transfer medium circulation piping, wherein the heater control device controls the supply of power to the auxiliary heater using the higher of the detected temperature detected by the auxiliary temperature sensor and the detected temperature detected by the outlet temperature sensor. According to this, if the temperature detected by the auxiliary temperature sensor is higher than the temperature detected by the outlet temperature sensor, that is, if the auxiliary temperature sensor is properly detecting the temperature of the heat transfer medium in the heat transfer medium circulation piping heated by the auxiliary heater, the auxiliary heater can be precisely controlled based on the temperature detected by the auxiliary temperature sensor so that the temperature of the heat transfer medium flowing into the heat utilization equipment reaches the target temperature. On the other hand, if the temperature detected by the auxiliary temperature sensor is lower than the temperature detected by the outlet temperature sensor, that is, if the temperature detected by the auxiliary temperature sensor deviates significantly from the temperature of the heat transfer medium passing through the heat transfer medium circulation piping due to an abnormality in the mounting condition of the auxiliary temperature sensor to the heat transfer medium circulation piping, the auxiliary heater can be controlled based on the temperature detected by the outlet temperature sensor so that the temperature of the heat transfer medium flowing into the heat utilization equipment reaches the target temperature.

[0072] (Technology 3) The heat transfer medium circulation system according to Technology 2, wherein the heater control device detects whether the connection with the auxiliary temperature sensor is good or not, and when the connection with the auxiliary temperature sensor is poor, controls the supply of power to the auxiliary heater using the detected temperature detected by the outlet temperature sensor. According to this, even if an auxiliary temperature sensor is not attached to the heat transfer medium circulation piping, or if the auxiliary temperature sensor is not properly connected to the heater control device, the heat transfer medium can still be heated by the auxiliary heater.

[0073] (Technology 4) A heat transfer medium circulation system according to Technology 2 or 3, further comprising a remote control for giving operation instructions to the outdoor unit and a server, wherein when the heater control device detects a faulty connection with the auxiliary temperature sensor, it notifies the user of the faulty connection with the auxiliary temperature sensor via the remote control and notifies the server of the faulty connection. According to this, for example, if a connection problem with the auxiliary temperature sensor is detected during the trial run when installing the heat transfer fluid circulation system, a notification will be sent via the remote control and to the server, allowing for quick action to be taken in cases of forgetting to attach the auxiliary temperature sensor to the heat transfer fluid circulation piping or abnormal installation of the auxiliary temperature sensor.

[0074] (Technical 5) A method for controlling the temperature of a heat medium, performed by a heater control device of a heat medium circulation system comprising: an outdoor unit that supplies a heated heat medium; a heat utilization facility that utilizes the heat of the heat medium supplied from the outdoor unit indoors; a heat medium circulation pipe that circulates the heat medium between the outdoor unit and the heat utilization facility; an auxiliary heater mounted on the outer circumference of the heat medium circulation pipe in the portion of the heat medium circulation pipe upstream of the heat utilization facility along the flow of the heat medium; an auxiliary temperature sensor mounted on the outer circumference of the heat medium circulation pipe in the portion of the heat medium circulation pipe between the auxiliary heater and the heat utilization facility; and an outlet temperature sensor provided on the outdoor unit that measures the temperature of the heat medium flowing out into the heat medium circulation pipe, the method for controlling the temperature of a heat medium, comprising: the heater control device controlling the supply of power to the auxiliary heater using the higher of the detected temperature detected by the auxiliary temperature sensor and the detected temperature detected by the outlet temperature sensor. According to this, it produces the same effects as techniques 1 and 2. [Industrial applicability]

[0075] The heat transfer medium circulation system and heat transfer medium temperature control method described herein are suitably applicable as a heat transfer medium circulation system and a heat transfer medium temperature control method that enable the later addition of a heater to supplementarily heat the heat transfer medium, thereby improving convenience. [Explanation of Symbols]

[0076] 1. Heat transfer fluid circulation system 2 Outdoor unit 3 Total heat exchanger 4 Heat medium circulation piping 5. Auxiliary heater 5a Sheet-type heater 5b, 6b Insulation cover 6. Auxiliary temperature sensor 6a Sheet-type temperature sensor 7. Heater control device 8 Remote control 9 Servers 20a Refrigerant piping 20b Heat medium piping 21 Compressor 22 Pressure Reducing Device 23 Evaporator 24 Four-way valve 25 Water refrigerant heat exchanger 26. Blower fan 27a Outlet connector 27b Inlet Connector 28a Outlet temperature sensor 28b Inlet temperature sensor 29 Control device 50, 60, 61 Insulation materials 70 processors 71 memory 72 Communication equipment 73 Programs 74 Operation Control Unit 75 Information Gathering Department H building NW (Network Communication Network) S Indoor space PA Piping Area

Claims

1. An outdoor unit that supplies a heated heat transfer medium, A heat utilization system that utilizes the heat of the heat transfer medium supplied from the outdoor unit inside the room, A heat transfer medium circulation pipe for circulating the heat transfer medium between the outdoor unit and the heat utilization equipment, In the heat transfer medium circulation piping, in the portion upstream of the heat utilization equipment along the flow of the heat transfer medium, an auxiliary heater is attached to the outer circumference of the heat transfer medium circulation piping, Having, Heat transfer fluid circulation system.

2. A heater control device that controls the operation of the auxiliary heater, In the portion of the heat transfer medium circulation piping between the auxiliary heater and the heat utilization equipment, an auxiliary temperature sensor is mounted on the outer circumference of the heat transfer medium circulation piping, An outlet temperature sensor is provided on the outdoor unit for measuring the temperature of the heat transfer medium flowing into the heat transfer medium circulation piping, Equipped with, The heater control device controls the supply of power to the auxiliary heater using the higher of the detected temperature detected by the auxiliary temperature sensor and the detected temperature detected by the outlet temperature sensor. The heat transfer fluid circulation system according to claim 1.

3. The heater control device detects whether the connection to the auxiliary temperature sensor is good or not, and if the connection to the auxiliary temperature sensor is poor, it controls the power supply to the auxiliary heater using the detected temperature detected by the outlet temperature sensor. The heat transfer medium circulation system according to claim 2.

4. A remote control that gives operating instructions to the outdoor unit, Server and Furthermore, When the heater control device detects a connection failure with the auxiliary temperature sensor, it notifies the user of the connection failure with the auxiliary temperature sensor via the remote control and also notifies the server of the connection failure. The heat transfer medium circulation system according to claim 2 or 3.

5. A method for controlling the temperature of a heat medium, performed by a heater control device for a heat medium circulation system comprising: an outdoor unit that supplies a heated heat medium; heat utilization equipment that utilizes the heat of the heat medium supplied from the outdoor unit indoors; heat medium circulation piping that circulates the heat medium between the outdoor unit and the heat utilization equipment; an auxiliary heater mounted on the outer circumference of the heat medium circulation piping in the portion of the heat medium circulation piping upstream of the heat utilization equipment along the flow of the heat medium; an auxiliary temperature sensor mounted on the outer circumference of the heat medium circulation piping in the portion of the heat medium circulation piping between the auxiliary heater and the heat utilization equipment; and an outlet temperature sensor provided on the outdoor unit that measures the temperature of the heat medium flowing out into the heat medium circulation piping, wherein the heater control device performs the control of the heat medium temperature, The heater control device includes controlling the supply of power to the auxiliary heater using the higher of the detected temperature detected by the auxiliary temperature sensor and the detected temperature detected by the outlet temperature sensor. A method for controlling the temperature of a heat transfer medium.

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