Fluid circulation device

Abstract

To provide a fluid circulation device capable of accurately determining whether a measurement specification of a flow rate measurement portion is different or not before and after a replacement work.SOLUTION: In a fluid circulation device 1, a state determination portion C1J executes: after-installation check processing S101, S102 for storing an after-installation signal SG1 in a storage portion C1M in completion of an installation work of the fluid circulation device 1; reference range setting processing S111 for setting an upper limit value G1H and a lower limit value G1L while adding a prescribed allowable error T1 to the after-installation signal SG1; after-replacement check processing S121, S122 for storing an after-replacement signal SG2 in the storage portion C1M in completion of a replacement work of a flow rate measurement portion 10; and determination processing S131-S138 for determining occurrence of a first error in which a measurement specification of the flow rate measurement portion 10 is different before and after the replacement work, and making a notification portion C1N perform first notification corresponding to the first error, in a case when the after-replacement signal SG2 is more than the upper limit value G1H or the after- replacement signal SG2 is smaller than the lower limit value G1L.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a fluid circulation device.

Background Art

[0002] Patent Document 1 discloses an example of a conventional fluid circulation device, a hot water storage type water heater. This hot water storage type water heater is a stationary type and includes a circulation circuit which is an example of a flow path, a heat source pump, a flow sensor which is an example of a flow rate measurement unit, a control unit which is an example of a storage unit and a state determination unit, and a notification unit.

[0003] The circulation circuit circulates hot water which is an example of a fluid. The heat source pump is provided in the circulation circuit and pumps the hot water. The flow sensor measures the flow rate of the hot water flowing through the circulation circuit.

[0004] The control unit has a storage circuit, determines a failure of the flow sensor based on the normal range of the flow sensor pre-stored in the storage circuit and the measurement result of the flow sensor, and causes the notification unit to notify the fact.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in a conventional fluid circulation device such as the above-described hot water storage type water heater, the flow rate measurement unit outputs a signal corresponding to the flow rate of the fluid flowing in the flow path, and any one of a plurality of flow rate measurement units having different measurement specifications which are the correlation between the flow rate and the signal can be selected and attached to the flow path.

[0007] A concrete example of a configuration with different measurement specifications is an impeller-type flow rate measuring unit where the shape of the housing mounting part and the inner diameter of the internal flow path are the same, but differences in the shape of the impeller blades arranged in the internal flow path result in different impeller rotation speeds when the flow rate is the same, and consequently, different signal pulse counts.

[0008] Another specific example is a configuration in which, although the shape of the housing mounting part is the same, differences in the inner diameter of the internal flow path and the size of the impeller result in different impeller rotation speeds when the flow rate is the same, and consequently, different signal pulse counts.

[0009] In this configuration, where any one of several flow measurement units with different measurement specifications can be selected and installed in the flow path, there is a risk that during replacement work, a flow measurement unit with different measurement specifications than the one installed may be mistakenly installed.

[0010] In this case, even if the condition determination unit performs the same determination as the determination of a failure of the flow sensor in the above-mentioned storage-type water heater, it will only determine that the flow rate measurement unit has failed, and will not be able to determine whether the measurement specifications of the flow rate measurement unit are different before and after the replacement work.

[0011] Furthermore, in stationary fluid circulation systems, the length of the flow path varies greatly depending on the installation location. For example, if the fluid circulation system is a water heater, the length of the flow path connecting the water heater, which is mainly installed outdoors in houses and facilities, to faucets and other fixtures installed in kitchens, bathrooms, etc., varies greatly depending on differences in the size of the house, etc.

[0012] Therefore, for each flow rate measuring unit, the measurement specifications after installation tend to vary significantly from the measurement specifications at the time of design. As a result, even if the measurement specifications for each flow rate measuring unit at the time of design are pre-stored in the memory unit and used for judgment regarding the flow rate measuring unit, it is difficult to make accurate judgments with this fluid circulation device.

[0013] This invention has been made in view of the above-mentioned conventional circumstances, and aims to solve the problem of providing a fluid circulation device that can accurately determine whether the measurement specifications of the flow rate measuring unit differ before and after replacement work. [Means for solving the problem]

[0014] The fluid circulation device of the present invention comprises a flow path for circulating fluid, A pump provided in the aforementioned flow path for pressurizing the fluid, A flow rate measuring unit that outputs a signal corresponding to the flow rate of the fluid flowing in the flow path, wherein any one of a plurality of flow rate measuring units, each having different measurement specifications that represent the correlation between the flow rate and the signal, is selected and attached to the flow path, A storage unit that stores at least the aforementioned signals, A state determination unit for determining the state of the flow rate measuring unit, The news department that provides the information, A stationary fluid circulation device comprising: The state determination unit, A post-installation check process is performed in which, upon completion of the installation work of the fluid circulation device, the pump is operated under predetermined test operating conditions, and the signal output by the flow rate measuring unit is stored in the storage unit as a post-installation signal. A reference range setting process that sets upper and lower limits by adding a predetermined tolerance to the post-installation signal stored in the memory unit, A post-replacement check process is performed in which, upon completion of the replacement of the flow rate measuring unit, the pump is operated under the test operation conditions, and the signal output by the flow rate measuring unit is stored in the storage unit as a post-replacement signal. If the post-replacement signal is greater than the upper limit, or if the post-replacement signal is less than the lower limit, a determination process is performed to determine that a first error has occurred in which the measurement specifications of the flow rate measuring unit differ before and after the replacement work, and to cause the notification unit to issue a first notification corresponding to the first error. It is characterized by being configured to perform the following:

[0015] Regarding the fluid circulation device of the present invention, in the post-installation check process, the state determination unit causes the storage unit to store a post-installation signal when the installation work is completed. The post-installation signal corresponds to the length of the flow path according to the installation location of the fluid circulation device, and accurately reflects the measurement specifications after the installation of the flow rate measurement unit, that is, before replacement.

[0016] Next, in the reference range setting process, the state determination unit sets an upper limit value and a lower limit value in consideration of a predetermined tolerance for the post-installation signal.

[0017] Next, in the post-replacement check process, the state determination unit causes the storage unit to store a post-replacement signal when the replacement work of the flow rate measurement unit is completed.

[0018] Next, in the determination process, the state determination unit uses the upper limit value and the lower limit value based on the post-installation signal for comparison with the post-replacement signal to determine whether the measurement specifications of the flow rate measurement unit are different before and after the replacement work.

[0019] That is, the state determination unit corresponds to the length of the flow path according to the installation location of the fluid circulation device, and by using the post-installation signal that accurately reflects the measurement specifications after the installation of the flow rate measurement unit, that is, before replacement, for the determination of the flow rate measurement unit, compared with the case where the measurement specifications at the time of design of each flow rate measurement unit are stored in the storage unit in advance and used for the determination of the flow rate measurement unit, the determination accuracy can be improved.

[0020] Therefore, the fluid circulation device of the present invention can accurately determine whether the measurement specifications of the flow rate measurement unit are different before and after the replacement work. As a result, when it is determined that the measurement specifications of the flow rate measurement unit in this fluid circulation device are different before and after the replacement work, the replacement operator can promptly perform the work of replacing the incorrect flow rate measurement unit with the correct one.

[0021] It is desirable that the memory unit stores in advance a threshold value that is lower than each lower limit value of each flow rate measurement unit and greater than zero. Then, in the determination process, when the post-exchange signal is smaller than the threshold value, the state determination unit determines that a second error has occurred, that is, the flow rate measurement unit after the exchange is in a failed state, and it is desirable to cause the notification unit to perform a second notification corresponding to the second error instead of the first notification.

[0022] In this case, in the determination process, the state determination unit can distinguish and determine the occurrence of the first error and the occurrence of the second error. If it is determined that the first error has occurred, it can cause the notification unit to perform the first notification, and if it is determined that the second error has occurred, it can cause the notification unit to perform the second notification. As a result, this fluid circulation device can more accurately determine whether the measurement specifications of the flow rate measurement unit differ before and after the replacement work and notify the replacement operator, and can also distinguish and determine the state in which the flow rate measurement unit after the replacement has failed and notify the replacement operator. As a result, the convenience of the replacement operator can be improved.

Advantages of the Invention

[0023] According to the fluid circulation device of the present invention, it is possible to accurately determine whether the measurement specifications of the flow rate measurement unit differ before and after the replacement work.

Brief Description of the Drawings

[0024] [Figure 1] FIG. 1 is a schematic diagram of a water heater according to an embodiment. [Figure 2] FIG. 2 is a graph illustrating installation signals, upper limit values, lower limit values, and threshold values for a plurality of flow rate measurement units having different measurement specifications. [Figure 3] FIG. 3 is a flowchart of a first program related to post-installation check processing and reference range setting processing. [Figure 4] FIG. 4 is a flowchart of a second program related to post-exchange check processing and determination processing.

Modes for Carrying Out the Invention

[0025] The following describes embodiments of the present invention with reference to the drawings.

[0026] (Examples) As shown in Figure 1, the water heater 1 in this embodiment is an example of a specific embodiment of the fluid circulation device of the present invention. The water heater 1 is a stationary type mainly installed outdoors in houses and the like, and is a device that supplies high-temperature hot water to a mixing faucet 8 installed in a kitchen, bathroom, etc.

[0027] The water heater 1 is housed in a roughly box-shaped casing 1B and includes a control unit C1, a gas burner 7, a fuel gas pipe 71, a main valve 72, and a flow control valve 73.

[0028] The control unit C1 is an electronic circuit unit comprising a CPU (not shown), a storage unit C1M composed of memory elements such as ROM and RAM, an interface circuit for sending and receiving signals with the controlled object, and a power supply circuit for controlling the power supply to the controlled object.

[0029] The memory unit C1M stores various programs and setting information for operating the water heater 1. The memory unit C1M also appropriately stores various information acquired by the control unit C1 during the operation of the water heater 1.

[0030] The programs controlled by the memory unit C1M include the "first program related to post-installation check processing and reference range setting processing" shown in Figure 3, and the "second program related to post-replacement check processing and judgment processing" shown in Figure 4. When the control unit C1 executes the first and second programs, a part of the control unit C1 functions as the state determination unit C1J and the notification unit C1N, which will be described later.

[0031] The fuel gas pipe 71 is connected to a fuel gas supply source (not shown), such as a city gas supply pipe, and supplies fuel gas to the gas burner 7. The main valve 72 is a solenoid valve that switches the opening and closing of the fuel gas pipe 71. The flow control valve 73 is a solenoid valve that adjusts the flow rate of fuel gas supplied to the gas burner 7 via the fuel gas pipe 71.

[0032] The gas burner 7 starts combustion when the main valve 72 is opened by the control unit C1 and ignited by an ignition device (not shown). Then, the gas burner 7 burns with a heat output corresponding to the hot water load and generates combustion exhaust gas by adjusting the opening of the flow control valve 73 and the rotation speed of a blower fan (not shown) by the control unit C1.

[0033] Furthermore, the water heater 1 is equipped with a heat exchanger 3, a first internal pipe 31, a second internal pipe 32, a first temperature sensor 31T, a flow rate measuring unit 10, a second temperature sensor 32T, and a pump 5 within the housing 1B.

[0034] The heat exchanger 3 is located above the gas burner 7. The lower end of the first internal piping 31 is connected to a pipe joint 91 located on the bottom wall of the housing 1B. The upper end of the first internal piping 31 is connected to the water inlet side of the heat exchanger 3. The upper end of the second internal piping 32 is connected to the water outlet side of the heat exchanger 3. The lower end of the second internal piping 32 is connected to a pipe joint 92 located on the bottom wall of the housing 1B.

[0035] The first temperature sensor 31T is located in the middle of the first internal piping 31, near the lower end of the first internal piping 31. The first temperature sensor 31T measures the temperature of the hot water flowing through the first internal piping 31, that is, the hot water before it is heated by the heat exchanger 3, and transmits the measurement result to the control unit C1.

[0036] The flow rate measuring unit 10 is located in the middle of the first internal piping 31. The flow rate measuring unit 10 measures the flow rate of hot and cold water circulating in the first internal piping 31 and transmits the measurement result to the control unit C1. The details of the flow rate measuring unit 10 will be explained in detail later.

[0037] The second temperature sensor 32T is located in the middle of the second internal piping 32. The second temperature sensor 32T measures the temperature of the hot water flowing through the second internal piping 32, that is, the hot water after it has been heated by the heat exchanger 3, and transmits the measurement result to the control unit C1.

[0038] Pump 5 is located in the middle of the second internal piping 32, near the lower end of the second internal piping 32. Pump 5 is operated by the control unit C1 and pumps hot water towards the lower end of the second internal piping 32.

[0039] Furthermore, the water heater 1 is equipped with a first external pipe 41, a second external pipe 42, and a third external pipe 43 on the outside of the housing 1B.

[0040] One end of the first external pipe 41 is connected to the lower end of the first internal pipe 31 via a pipe joint 91. The other end of the first external pipe 41 is connected to a T-type pipe joint 93.

[0041] One end of the second external pipe 42 is connected to the lower end of the second internal pipe 32 via a pipe joint 92. The other end of the second external pipe 42 is connected to one end of the third external pipe 43 and to the high-temperature water introduction pipe 8H of the mixing faucet 8 via a T-type pipe joint 94.

[0042] The other end of the third external pipe 43 is connected to the other end of the first external pipe 41 via a T-type pipe joint 93.

[0043] A check valve 43V is positioned in the middle of the third external piping 43, near the T-type pipe joint 93. The check valve 43V allows the hot and cold water in the third external piping 43 to flow toward the first external piping 41, while restricting its flow in the opposite direction.

[0044] The other end of the first external pipe 41 and the other end of the third external pipe 43 are connected to one end of the first water supply branch pipe 51 via a T-shaped pipe joint 93.

[0045] The other end of the first water supply branch pipe 51 is connected to one end of the main water supply pipe 50 and one end of the second water supply branch pipe 52 via a T-shaped pipe joint 95.

[0046] The other end of the main water supply pipe 50 is connected to a water supply source (not shown), such as a public water supply. The other end of the second water supply branch pipe 52 is connected to the low-temperature water introduction pipe 8L of the mixing faucet 8.

[0047] A check valve 50V is installed in the middle of the main water supply pipe 50. The check valve 50V allows the hot and cold water in the main water supply pipe 50 to flow toward the first water supply branch pipe 51 and the second water supply branch pipe 52, while restricting its flow toward the opposite direction.

[0048] An expansion valve 50W is located in the middle of the main water supply pipe 50, near the T-type pipe joint 95. The expansion valve 50W absorbs the pressure increase in the main water supply pipe 50, the first water supply branch pipe 51, and the second water supply branch pipe 52.

[0049] The main water supply pipe 50 and the first water supply branch pipe 51 supply unheated water to the first internal pipe 31 of the water heater 1 via the first external pipe 41.

[0050] The water heater 1 is equipped with a water flow rate measuring unit 15 located in the middle of the first water supply branch pipe 51. The water flow rate measuring unit 15 measures the flow rate of water circulating in the first water supply branch pipe 51 and transmits the measurement result to the control unit C1.

[0051] The main water supply pipe 50 and the second water supply branch pipe 52 supply unheated water to the low-temperature water inlet pipe 8L of the mixing valve 8 when the low-temperature water discharge side of the mixing valve 8 is opened.

[0052] The water heater 1 is equipped with a remote control 80 installed around the mixing faucet 8 in the kitchen, bathroom, etc. The remote control 80 has an operation unit 81 and a display unit 82.

[0053] The control unit 81 has multiple buttons and accepts operation inputs such as starting and stopping the water heater 1, executing instant hot water operation, and inputting various setting information such as the target hot water temperature. The operation inputs received by the control unit 81 are transmitted to the control unit C1.

[0054] The display unit 82 is a liquid crystal display or the like. The display unit 82 is controlled by the control unit C1 and displays the operating status of the water heater 1, various setting information, error messages, etc., as appropriate.

[0055] <Hot water supply operation> When the user operates the remote control 80 to start the water heater 1, the control unit C1 enters a standby state for hot water supply operation.

[0056] During hot water supply operation, the control unit C1 puts the gas burner 7 into a standby state where it can be ignited immediately. During hot water supply operation, the pump 5 remains stopped and does not obstruct the flow of hot and cold water in the second internal piping 32.

[0057] When the hot water discharge side of the mixing faucet 8 is opened, water supplied from the water supply source flows through the main water supply pipe 50, the first water supply branch pipe 51, the first external pipe 41, the first internal pipe 31, the heat exchanger 3, the second internal pipe 32, the second external pipe 42, and the hot water introduction pipe 8H, and is discharged from the mixing faucet 8.

[0058] At this point, the control unit C1 determines that the high-temperature water discharge side of the mixing valve 8 has been opened based on the fact that the measured flow rates of the water supply flow rate measuring unit 15 and the flow rate measuring unit 10 are greater than zero, and immediately ignites the gas burner 7. The heat exchanger 3 heats the water flowing inside it with the combustion exhaust gas generated by the gas burner 7.

[0059] Then, based on the measurement results of the first temperature sensor 31T and the second temperature sensor 32T, the control unit C1 adjusts the heat output of the gas burner 7 so that the temperature of the hot water supplied from the water heater 1 reaches the target hot water supply temperature. As a result, hot water is discharged from the mixing faucet 8. If the low-temperature water discharge side of the mixing faucet 8 is also open, the mixing faucet 8 mixes the hot water with the low-temperature water and discharges it.

[0060] When the hot water outlet side of the mixing faucet 8 is closed, or when the user stops the water heater 1 using the remote control 80, the control unit C1 extinguishes the gas burner 7 and terminates the hot water supply operation.

[0061] <Instant Hot Water Operation> When the user operates the remote control 80 to start the water heater 1 and selects instant hot water operation, the control unit C1 starts instant hot water operation.

[0062] In instant hot water operation, the control unit C1 activates the pump 5 and ignites the gas burner 7. Then, the first external piping 41, the first internal piping 31, the heat exchanger 3, the second internal piping 32, the second external piping 42, and the third external piping 43 circulate the hot water pressurized by the pump 5. The heat exchanger 3 heats the water circulating inside with the combustion exhaust gas generated by the gas burner 7.

[0063] The circulation channel 2 is composed of the first external piping 41, the first internal piping 31, the heat exchanger 3, the second internal piping 32, the second external piping 42, and the third external piping 43. The circulation channel 2 is an example of a "channel" in the present invention. Hot water is an example of a "fluid" in the present invention.

[0064] Based on the fact that the measured flow rate of the water supply flow rate measuring unit 15 is zero, the control unit C1 determines that the hot water discharge side of the mixing faucet 8 is closed, and also determines that the measured flow rate of the flow rate measuring unit 10 is the flow rate of hot and cold water circulating in the circulation channel 2.

[0065] Then, based on the measurement results of the first temperature sensor 31T and the second temperature sensor 32T, the control unit C1 adjusts the flame output of the gas burner 7 or causes the gas burner 7 to burn intermittently so that the temperature of the hot water circulating in the circulation channel 2 becomes the target hot water supply temperature.

[0066] When the hot water discharge side of the mixing valve 8 is opened, a portion of the hot water circulating in the circulation channel 2 flows from the other end of the first external pipe 41 into the hot water introduction pipe 8H of the mixing valve 8. As a result, hot water is immediately discharged from the mixing valve 8. If the cold water discharge side of the mixing valve 8 is also open, the mixing valve 8 mixes the hot water with cold water and discharges it.

[0067] At this time, the main water supply pipe 50 and the first water supply branch pipe 51 replenish the circulation channel 2 with water according to the amount of water that has flowed out from the circulation channel 2 into the high-temperature water introduction pipe 8H. Based on the fact that the measured flow rate of the water supply flow rate measuring unit 15 is greater than zero, the control unit C1 determines that the high-temperature water discharge side of the mixing tap 8 has been opened, and also determines that the temperature of the hot and cold water has decreased as water has been replenished in the circulation channel 2.

[0068] Then, based on the measurement results of the first temperature sensor 31T and the second temperature sensor 32T, the control unit C1 adjusts the heat output of the gas burner 7 so that the temperature of the hot water circulating in the circulation channel 2 becomes the target hot water supply temperature.

[0069] When the user stops the water heater 1 using the remote control 80, the control unit C1 extinguishes the gas burner 7 and stops the pump 5, ending the instant hot water operation.

[0070] <Details of the flow rate measurement unit> Although simplified in the illustration, the flow rate measuring unit 10 includes a housing with an attachment portion for installation in the middle of the first internal piping 31, an internal flow path formed in the housing, and an impeller arranged in the internal flow path.

[0071] The impeller is rotatable around a rotation axis parallel to the direction in which the internal flow path extends, and has blades that extend spirally around the rotation axis. The number of rotations of the impeller per unit time (seconds) increases in proportion to the flow rate of hot water circulating in the first internal piping 31.

[0072] Furthermore, the flow rate measuring unit 10 includes a magnet attached to the outer edge of the impeller and a magnetic sensor attached to a location close to the inner wall surface of the internal flow path in the housing. The internal contacts of the magnetic sensor are closed when the magnet is far away during one rotation of the impeller, and switch to a connected state and emit a pulse signal only when the magnet is closest.

[0073] Therefore, the signal (pulses / second) transmitted by the flow rate measuring unit 10 increases in proportion to the flow rate of hot and cold water circulating in the first internal piping 31.

[0074] The flow rate of hot and cold water circulating in the first internal piping 31 increases in proportion to the rotational speed of the pump 5 per unit time (second). In other words, the signal (number of pulses / second) emitted by the flow rate measuring unit 10 increases in proportion to the rotational speed of the pump 5 per unit time (second).

[0075] The correlation between the flow rate of hot and cold water circulating in the first internal piping 31 (the number of rotations per unit time (second) of the pump 5) and the signal from the flow rate measuring unit 10 (number of pulses / second) is defined as the measurement specification for the flow rate measuring unit 10.

[0076] The flow rate measuring unit 10 is installed in the first internal piping 31 by selecting one of two flow rate measuring units 10, namely the first flow rate measuring unit 10A and the second flow rate measuring unit 10B, each with different measurement specifications.

[0077] The first flow rate measuring unit 10A and the second flow rate measuring unit 10B have the same housing mounting shape and internal flow path diameter, but due to differences in the shape of the impeller blades arranged in the internal flow path, the rotation speed of the impeller differs when the flow rate is the same, resulting in a difference in the number of signal pulses.

[0078] For more details, an example of the measurement specifications for the first flow rate measuring unit 10A after the installation of the water heater 1 is shown by the solid line L1 in Figure 2. Also, an example of the measurement specifications for the second flow rate measuring unit 10B after the installation of the water heater 1 is shown by the dashed line L2 in Figure 2.

[0079] The second flow rate measuring unit 10B is a low-flow rate operating type, in which the impeller starts rotating at a low flow rate, compared to the first flow rate measuring unit 10A. In addition, the second flow rate measuring unit 10B has a higher impeller rotation speed and a higher pulse count / second in the signal at the same flow rate compared to the first flow rate measuring unit 10A.

[0080] The second flow rate measuring unit 10B is used to enable the water heater 1 to supply hot water in a way that responds accurately to the fine operation of the mixing valve 8.

[0081] The selection of either the first flow rate measuring unit 10A or the second flow rate measuring unit 10B is performed during the manufacture of the water heater 1, and the control unit C1 is also set to determine the flow rate of hot and cold water circulating in the first internal piping 31 according to the measurement specifications of the selected first flow rate measuring unit 10A or the second flow rate measuring unit 10B.

[0082] The houses in which the water heater 1 is installed vary in size and the arrangement of multiple rooms. Therefore, the length of the circulation path 2 of the water heater 1 varies depending on the house in which the water heater 1 is installed, which may cause the measurement specifications of the first flow rate measuring unit 10A after the installation of the water heater 1 to deviate from the solid line L1, or the measurement specifications of the second flow rate measuring unit 10B after the installation of the water heater 1 to deviate from the dashed line L2.

[0083] <First and second programs for determining whether the measurement specifications of the flow rate measuring unit differ before and after replacement work> When a water heater 1 is installed in a house and used for a long period of time, maintenance or repair work may be required to replace the flow rate measuring unit 10 with a new one. In this case, there is a risk of malfunction occurring during the replacement work of the flow rate measuring unit 10, such as mistakenly installing the second flow rate measuring unit 10B, which has different measurement specifications from the first flow rate measuring unit 10A after installation, into the first internal piping 31, or installing the first flow rate measuring unit 10A, which has different measurement specifications from the second flow rate measuring unit 10B after installation, into the first internal piping 31.

[0084] When such a malfunction occurs, the control unit C1 executes the "First Program for Post-Installation Check Processing and Reference Range Setting Processing" shown in Figure 3 and the "Second Program for Post-Replacement Check Processing and Judgment Processing" shown in Figure 4 to notify the replacement worker of the malfunction.

[0085] After the installation of the water heater 1 is completed, when the installer operates the remote control 80 to turn on the power to the water heater 1 and perform a test run, the control unit C1 executes the first program shown in Figure 3 as one of several functional verification tests.

[0086] Steps S101 and S102 shown in Figure 3 are examples of the "post-installation check process" of the present invention. Step S111 shown in Figure 3 is an example of the "reference range setting process" of the present invention.

[0087] First, in step S101, the state determination unit C1J, which is part of the control unit C1, operates the pump 5 under predetermined test operation conditions. The hot water in the circulation channel 2 is pumped to the pump 5 and circulated.

[0088] The specified test operation conditions are as follows: the circulation channel 2, the main water supply pipe 50, the first water supply branch pipe 51, the second water supply branch pipe 52, the high-temperature water introduction pipe 8H, and the low-temperature water introduction pipe 8L are filled with water, the mixing valve 8 is closed, and the pump 5 is rotated at the rotation speed R1 shown in Figure 2.

[0089] The rotational speed R1 is set to a rotational speed such that the impellers of the first flow measurement unit 10A and the second flow measurement unit 10B rotate stably at high speed.

[0090] Furthermore, when the pump 5 operates at rotational speed R1, if there are initial defects, foreign matter intrusion, or improper installation of the first flow rate measuring unit 10A or the second flow rate measuring unit 10B, the rotational speed of the impeller will be significantly lower than in a normal state, and the number of pulses per second in the signal will be significantly lower. For this reason, the memory unit C1M stores the threshold value G2 shown in Figure 2 in advance.

[0091] The threshold G2 was set to a value greater than the result obtained by measuring the number of pulses / second in the signal when the pump 5 was operating at rotational speed R1, after experimentally induced initial defects, foreign matter intrusion, installation defects, etc., in the first flow measurement unit 10A and the second flow measurement unit 10B during the development of the water heater 1. Furthermore, the threshold G2 was set sufficiently low to account for variations in installation locations, relative to the measurement specifications at the time of design of the first flow measurement unit 10A and the second flow measurement unit 10B.

[0092] The threshold G2 set in this manner is lower than the lower limit G1L (G1LA, G1LB) of the first flow measurement unit 10A and the second flow measurement unit 10B, respectively, and greater than zero.

[0093] Next, the state determination unit C1J proceeds to step S102 shown in Figure 3, where the signal output by the flow rate measurement unit 10 is stored in the storage unit C1M as the post-installation signal SG1.

[0094] As shown in Figure 2, if the flow rate measuring unit 10 after installation is the first flow rate measuring unit 10A, the state determination unit C1J stores the signal SG1A output by the first flow rate measuring unit 10A as the installation signal SG1 in the storage unit C1M.

[0095] On the other hand, if the flow rate measuring unit 10 after installation is the second flow rate measuring unit 10B, the state determination unit C1J stores the signal SG1B output by the second flow rate measuring unit 10B as the post-installation signal SG1 in the storage unit C1M.

[0096] Next, the state determination unit C1J proceeds to step S105 shown in Figure 3, where it determines whether the post-installation signal SG1 (SG1A or SG1B) is less than the threshold G2. If the answer in step S105 is "Yes", the unit proceeds to step S106. On the other hand, if the answer in step S105 is "No", the unit proceeds to step S111.

[0097] When the system moves from step S105 to step S106, the state determination unit C1J determines that the flow rate measuring unit 10 has malfunctioned after installation.

[0098] Then, the status determination unit C1J moves to step S107, instructing the notification unit C1N, which is part of the control unit C1, to issue a notification indicating a malfunction of the flow rate measurement unit 10 after installation. The notification unit C1N controls the display unit 82 of the remote control 80 to display an error message indicating a malfunction of the flow rate measurement unit 10.

[0099] Subsequently, the status determination unit C1J terminates the first program. Upon seeing the error message, the installation worker can quickly replace the faulty flow measurement unit 10 with a working one.

[0100] When the system moves from step S105 to step S111, the state determination unit C1J sets the upper limit value G1H (G1HA or G1HB) and the lower limit value G1L (G1LA or G1LB) by adding a predetermined tolerance T1 to the post-installation signal SG1 (SG1A or SG1B) stored in the memory unit C1M, as shown in Figure 2. After that, the state determination unit C1J terminates the first program.

[0101] Here, when adding a predetermined tolerance T1 to the post-installation signal SG1, addition, subtraction, multiplication, division, etc., can be used. The following is an example where the tolerance T1 is a percentage. Upper limit G1H = Post-installation signal SG1 × (1 + predetermined allowable error T1 (%) / 100) Lower limit G1L = Post-installation signal SG1 × (1 - predetermined allowable error T1 (%) / 100)

[0102] When the water heater 1 is installed in a house and used for a long period of time, and the flow rate measuring unit 10 is replaced, and after the replacement work is completed, the worker operates the remote control 80 to turn on the power to the water heater 1 and perform a test run, the control unit C1 executes the second program shown in Figure 4 as one of several functional verification tests.

[0103] Steps S121 and S122 shown in Figure 4 are an example of the "post-replacement check process" of the present invention. Steps S131 to S138 shown in Figure 4 are an example of the "determination process" of the present invention.

[0104] First, in step S121, the state determination unit C1J operates the pump 5 under predetermined test operating conditions. The hot water in the circulation channel 2 is pumped to the pump 5 and circulated. The predetermined test operating conditions are the same as the predetermined test operating conditions in step 101 shown in Figure 3.

[0105] Next, the state determination unit C1J proceeds to step S122 shown in Figure 4, and stores the signal output by the flow rate measurement unit 10 as the exchanged signal SG2 in the storage unit C1M.

[0106] Next, the state determination unit C1J proceeds to step S131, where it determines whether the post-replacement signal SG2 is greater than the upper limit value G1H (G1HA or G1HB). If the answer in step S131 is "Yes", the unit proceeds to step S137. On the other hand, if the answer in step S131 is "No", the unit proceeds to step S132.

[0107] When the process moves from step S131 to step S132, the state determination unit C1J determines whether the replacement signal SG2 is smaller than the lower limit value G1L (G1LA or G1LB). If the answer in step S132 is "Yes", the process moves to step S134. On the other hand, if the answer in step S132 is "No", the process moves to step S133.

[0108] When the system moves from step S132 to step S133, the status determination unit C1J determines that the replaced flow rate measuring unit 10 is in a normal state, that is, the replaced flow rate measuring unit 10 is not malfunctioning and the measurement specifications of the flow rate measuring unit 10 are the same before and after the replacement work. After that, the status determination unit C1J terminates the second program.

[0109] When moving from step S132 to step S134, the state determination unit C1J determines whether the post-exchange signal SG2 is smaller than the threshold G2. If the answer in step S134 is "Yes", the process proceeds to step S135. On the other hand, if the answer in step S134 is "No", the process proceeds to step S137.

[0110] When the system moves from step S131 or step S134 to step S137, the state determination unit C1J determines that a first error has occurred in which the measurement specifications of the flow rate measurement unit 10 are different before and after the replacement work.

[0111] Next, the status determination unit C1J proceeds to step S138, causing the notification unit C1N to issue a first notification corresponding to the first error. The notification unit C1N controls the display unit 82 of the remote control 80 and displays an error message as the first notification, for example, "The measurement specifications of the flow rate measurement unit 10 are different before and after the replacement work."

[0112] Subsequently, the status determination unit C1J terminates the second program. Upon confirming the first notification, the replacement worker can quickly replace the incorrect flow rate measuring unit 10 (one of the first flow rate measuring unit 10A and the second flow rate measuring unit 10B) with the correct flow rate measuring unit 10 (the other of the first flow rate measuring unit 10A and the second flow rate measuring unit 10B).

[0113] When the system moves from step S134 to step S135, the state determination unit C1J determines that a second error has occurred, indicating that the replaced flow rate measuring unit 10 is in a malfunctioning state.

[0114] Then, the status determination unit C1J proceeds to step S136 and instructs the notification unit C1N to issue a second notification corresponding to the second error, rather than the first notification. The notification unit C1N controls the display unit 82 of the remote control 80 to display an error message indicating a malfunction of the flow rate measurement unit 10 as the second notification.

[0115] Subsequently, the status determination unit C1J terminates the second program. Upon seeing the error message, the replacement worker can quickly replace the faulty flow measurement unit 10 with a working flow measurement unit 10.

[0116] <Effects and Effects> In the water heater 1 of the embodiment, the status determination unit C1J stores the post-installation signal SG1 (SG1A or SG1B) in the storage unit C1M when the installation work is completed during the post-installation check process (steps S101 and S102 shown in Figure 3). The post-installation signal SG1 corresponds to the length of the circulation channel 2 according to the installation location of the water heater 1 and accurately reflects the measurement specifications of the flow rate measurement unit 10 after installation, i.e., before replacement.

[0117] Next, in the state determination unit C1J, in the reference range setting process (step S111 shown in Figure 3), adds a predetermined allowable error T1 to the post-installation signal SG1 (SG1A or SG1B) to set the upper limit value G1H (G1HA or G1HB) and the lower limit value G1L (G1LA or G1LB).

[0118] Next, in the post-replacement check process (steps S121 and S122 shown in Figure 4), the status determination unit C1J stores the post-replacement signal SG2 in the storage unit C1M when the replacement work of the flow rate measuring unit 10 is completed.

[0119] Next, in the determination process (steps S131 to S138 shown in Figure 4), the state determination unit C1J uses the upper limit value G1H (G1HA or G1HB) and lower limit value G1LG1L (G1LA or G1LB) based on the post-installation signal SG1 to compare with the post-replacement signal SG2 to determine whether the measurement specifications of the flow rate measurement unit 10 are different before and after the replacement work.

[0120] In other words, the state determination unit C1J corresponds to the length of the circulation channel 2 according to the installation location of the water heater 1, and by using the post-installation signal SG1, which accurately reflects the measurement specifications after the installation of the flow rate measurement unit 10, i.e., before replacement, for determination of the flow rate measurement unit 10, the determination accuracy can be improved compared to the case where the measurement specifications of each flow rate measurement unit 10, i.e., the first flow rate measurement unit 10A and the second flow rate measurement unit 10B at the time of design are pre-stored in the storage unit C1M and used for determination of the flow rate measurement unit 10.

[0121] Therefore, the water heater 1 of the embodiment can accurately determine whether the measurement specifications of the flow rate measuring unit 10 differ before and after replacement work. As a result, if it is determined that the measurement specifications of the flow rate measuring unit 10 differ before and after replacement work in this water heater 1, the replacement worker can quickly replace the incorrect flow rate measuring unit 10 (one of the first flow rate measuring unit 10A and the second flow rate measuring unit 10B) with the correct flow rate measuring unit 10 (the other of the first flow rate measuring unit 10A and the second flow rate measuring unit 10B).

[0122] Furthermore, in this water heater 1, the memory unit C1M pre-stores a threshold G2 that is lower than the lower limit G1L (G1LA, G1LB) of the first flow rate measuring unit 10A and the second flow rate measuring unit 10B, respectively, and greater than zero.Then, in the determination process (steps S131 to S138 shown in Figure 4), the state determination unit C1J determines that if the post-replacement signal SG2 is smaller than the threshold G2, a second error has occurred, indicating that the replaced flow rate measuring unit 10 is in a faulty state, and causes the notification unit C1N to issue a second notification corresponding to the second error, rather than the first notification.

[0123] With this configuration, the status determination unit C1J can distinguish between the occurrence of a first error and the occurrence of a second error in the determination process (steps S131 to S138 shown in Figure 4). If it determines that a first error has occurred, it can cause the notification unit C1N to issue a first notification, and if it determines that a second error has occurred, it can cause the notification unit C1N to issue a second notification. As a result, the water heater 1 can more accurately determine whether the measurement specifications of the flow rate measurement unit 10 differ before and after replacement work and notify the replacement worker, and can also distinguish and determine if the flow rate measurement unit 10 is malfunctioning after replacement and notify the replacement worker. As a result, the convenience for the replacement worker can be improved.

[0124] Although the present invention has been described above with reference to examples, it goes without saying that the present invention is not limited to the above examples and can be applied with appropriate modifications without departing from its spirit.

[0125] In this embodiment, the flow rate measuring unit 10 is installed in the first internal piping 31 by selecting one of two flow rate measuring units 10, namely the first flow rate measuring unit 10A and the second flow rate measuring unit 10B, each with different measurement specifications. However, the present invention is not limited to this configuration. The flow rate measuring unit may be installed in the flow path by selecting one of three or more flow rate measuring units, each with different measurement specifications.

[0126] In the embodiment, the impeller of the flow rate measuring unit 10 is rotatable around a rotation axis parallel to the direction in which the internal flow path extends, but the present invention is not limited to this configuration. For example, the flow rate measuring unit may have an impeller that is rotatable around a rotation axis perpendicular to the direction in which the internal flow path extends. Also, the flow rate measuring unit is not limited to an impeller type, but may be various types of flow meters such as a float type, ultrasonic type, or electromagnetic type. The signal from the flow rate measuring unit is not limited to a pulse signal, but may be an analog signal such as an increasing or decreasing voltage value or current value, or a digital signal showing a numerical value.

[0127] In this embodiment, the fluid circulation device is a water heater 1, but the present invention is not limited to this configuration. The fluid circulation device can be any stationary fluid circulation device, for example, a heating device that circulates hot water, or a temperature control device that circulates a heat transfer medium or refrigerant. [Industrial applicability]

[0128] The present invention can be used, for example, in residential equipment such as water heaters and heating systems that circulate hot water, and in factory equipment such as temperature control devices that circulate a heat transfer medium or refrigerant. [Explanation of Symbols]

[0129] 1… Fluid circulation device (water heater) 2…Flow channel (circulation channel) 5... Pump 10 (10A, 10B)...Flow rate measurement section (10A...1st flow measurement section, 10B...2nd flow measurement section) C1M…Storage unit C1J... State determination unit C1N... Hochi Department SG1…Signal after installation S101, S102... Post-installation check process T1...Prescribed tolerance G1H... Upper limit G1L...Lower limit S111...Reference range setting process SG2…Signal after replacement S121, S122... Post-replacement check process S131~S138... Judgment process G2... threshold

Claims

1. a flow path for circulating a fluid; a pump provided in the flow path for pumping the fluid; a flow rate measuring unit that outputs a signal corresponding to the flow rate of the fluid flowing through the flow path, the flow rate measuring unit being any one selected from a plurality of flow rate measuring units each having a different measurement specification, which is a correlation between the flow rate and the signal, and attached to the flow path; a storage unit that stores at least the signal; a state determination unit that determines a state of the flow rate measurement unit; a notification unit that issues a notification; A stationary fluid circulation device comprising: The state determination unit a post-installation check process in which, when the installation work of the fluid circulation device is completed, the pump is operated under predetermined test operation conditions, and the signal output by the flow rate measurement unit is stored in the memory unit as a post-installation signal; a reference range setting process for setting an upper limit value and a lower limit value by taking into account a predetermined allowable error in the post-installation signal stored in the storage unit; a post-replacement check process in which, when the replacement work of the flow rate measuring unit is completed, the pump is operated under the test operation conditions and the signal output by the flow rate measuring unit is stored in the memory unit as a post-replacement signal; a determination process in which, when the post-replacement signal is greater than the upper limit value or when the post-replacement signal is smaller than the lower limit value, it is determined that a first error has occurred in which the measurement specifications of the flow rate measurement unit are different before and after the replacement work, and the notification unit is caused to issue a first notification corresponding to the first error; A fluid circulation device configured to perform the above.

2. the storage unit pre-stores a threshold value that is lower than the lower limit value of each of the flow rate measurement units and greater than zero, The fluid circulation device described in claim 1, wherein, in the judgment process, if the post-replacement signal is smaller than the threshold value, the status judgment unit judges that a second error has occurred, in which the flow rate measuring unit after replacement has failed, and causes the notification unit to issue a second notification corresponding to the second error instead of the first notification.

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