Boiler Equipment

Abstract

To provide a boiler device that eliminates the need to provide a control device for controlling a plurality of boilers, separately from the boilers, and eliminates the need for an expensive flow rate sensor for temperature control of hot water.SOLUTION: One of a plurality of boilers A is made to function as a master boiler A1, and the others are made to function as slave boilers A2-A4. The master boiler A1 controls operation of the slave boilers A2-A4. Each of the boilers A1-A4 has a hot water outflow temperature control function of controlling the flow rate of a boiler water circulation pump 5 to make an adjustment so that a hot water outflow temperature becomes equal to a set temperature, and a boiler water temperature control function of controlling the thermal power of a burner 8 to make an adjustment so that a boiler water temperature becomes higher than the set temperature by a predetermined temperature.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a technique for controlling the outlet temperature of hot water to a set temperature using a plurality of boilers. [Background technology]

[0002] Conventionally, there has been known a technology that uses multiple boilers to heat and control hot water to a set temperature. By using multiple boilers, the capacity of each boiler can be reduced, which has the advantage of preventing a decrease in efficiency when the hot water output is low, compared to a configuration in which a single boiler covers the entire range of hot water output.

[0003] An example of a technique for controlling a plurality of boilers is the automatic number control method described in Patent Document 1. This control method will be briefly described below. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 3-11261

[0005] As shown in FIG. 4, multiple hot water boilers 101 described in Patent Document 1 are installed in parallel, and the multiple boiler devices 101 are connected to a load 102 such as a hot water supply facility by a hot water supply line 103 and a return line 104, and a flow rate sensor 108 is attached to the hot water supply line.

[0006] The load, such as a hot water supply equipment, is equipped with a heat exchanger 105 that transfers the heat of the hot water flowing from multiple boilers 101 through a hot water supply system 103 and a return system 104 to a load 102, such as a hot water supply equipment, and a circulation pump 106 that circulates the hot water back to the boiler 101 through the hot water supply system 103 from the multiple boilers 101, the upper header 111 as a hot water supply side collection point, the heat exchanger 105, the lower header 112 as a return side collection point for the hot water, and the return system 104.

[0007] In addition, the upper header 111 and the lower header 112 of the load 102 are provided with a temperature sensor 107 for detecting the temperature of the hot water collected therein, and a temperature sensor 110 for detecting the temperature of the circulating water (outlet hot water) of the load 102.

[0008] Reference numeral 109 denotes an automatic number controller that controls the number of hot water boilers 101 .

[0009] The heat source hot water, which has been heated by multiple hot water boilers 101 to a predetermined temperature, is circulated through a circulation system consisting of a hot water supply line 103, a heat exchanger 105, and a return line 104 by the operation of a circulation pump 106, and heat is exchanged in heat exchangers 105 provided individually for the loads 102, supplying heat to each load.

[0010] A temperature sensor 107 detects the temperature of the hot water collected in the upper header 111 and the lower header 112, and an automatic number controller 109 controls the number of hot water boilers 101 in operation according to the temperature difference between the two.

[0011] When controlling the number of hot water boilers 101, the priority order for starting and stopping is determined in advance, and the hot water boilers 101 are started and stopped according to that priority. In addition, in order to average the operating rate of each hot water boiler 101, the priority order is rotated as appropriate.

[0012] In addition, the flow rate sensor 108 detects the amount of circulating hot water from the heat source, and the required heat quantity is calculated based on this circulation rate and the temperature difference between the hot water temperature in the upper header 111 and the hot water temperature in the lower header 112, and the number of hot water boilers 101 in operation is controlled according to this value.

[0013] When the circulation rate of the heat source hot water is varied, the temperature of the outlet hot water is detected by a temperature sensor 110 to control the operation of the circulation pump 106. If the load decreases and the required heat amount decreases, the number of hot water boilers 101 in operation is reduced, and if the load increases and the required heat amount increases, the number of hot water boilers 101 in operation is controlled to be increased. Summary of the Invention [Problem to be solved by the invention]

[0014] As described above, the hot water boiler has the functions of controlling the number of hot water boilers 101 to be operated depending on the magnitude of the temperature difference detected by two temperature sensors installed in the circulation path of the heat-source hot water, calculating the required heat quantity depending on the detection results of the flow rate sensor 108 and two temperature sensors installed in the circulation path of the heat-source hot water and controlling the number of hot water boilers 101 to be operated depending on this value, and detecting the outlet hot water temperature with temperature sensor 110 and controlling the operation of circulation pump 106 to vary the circulation amount of the heat-source hot water. Such number control is performed by an automatic number controller 109 in a higher-level system of the hot water boiler 101.

[0015] Therefore, an automatic unit number controller 109 is required in addition to the multiple boilers 101. Also, a flow rate sensor 108 is required to calculate the required amount of heat. Since the flow rate sensor is relatively expensive, the cost is high.

[0016] Furthermore, the need for the automatic unit count controller 109 complicates the system configuration.

[0017] SUMMARY OF THE PRESENT DISCLOSURE OF THE PRESENT DISCLOSURE An object of the present invention is to provide a boiler system that does not include an automatic number controller or a flow rate sensor that are installed separately from the hot water boiler. [Means for solving the problem]

[0018] The invention described in claim 1 includes a boiler body for storing boiler water, a burner for heating the boiler water, a pump for circulating boiler water between the boiler body and a heat transfer medium flow pipe connected to the outside of the boiler body, a boiler water temperature measuring temperature sensor for measuring the boiler water temperature flowing through the heat transfer medium flow pipe, a heat exchanger attached to the middle of the heat transfer medium flow pipe, a water inlet pipe and a hot water outlet pipe connected via the heat exchanger, a hot water outlet pipe temperature measuring temperature sensor for measuring the water temperature in the hot water outlet pipe, and a heating power command to the burner and a heating power command to the pump by detecting measured temperature information from the boiler water temperature measuring temperature sensor and the hot water outlet pipe temperature measuring temperature sensor. The boiler is provided with a plurality of boilers each having a controller for controlling the drive / stop of a boiler, and the temperature of the hot water flowing through the hot water outlet pipe is controlled by the plurality of boilers. One of the plurality of boilers functions as a master boiler, and the other boilers function as slave boilers. The master boiler controls itself and the slave boilers so that the temperature of the hot water flowing through the hot water outlet pipe becomes a set temperature. The control combines a hot water outlet temperature control that controls the flow rate of a boiler water circulation pump and a boiler water temperature control that controls the heat of a burner and adjusts the boiler water temperature to be a certain temperature higher than the set temperature. The master boiler alone heats the hot water to the set temperature, and if the master boiler alone cannot heat the hot water to the set temperature, all of the slave boilers are operated simultaneously to heat the hot water to the set temperature. It is characterized by the following.

[0019] The invention as recited in claim 2 is characterized in that the outlet heated water temperature control as recited in claim 1 is PI control.

[0020] The invention as recited in claim 3 is characterized in that the boiler water temperature control as recited in either claim 1 or claim 2 is PI control. Effect of the Invention

[0021] According to the invention described in claim 1, there is no need to provide a higher-level control device for controlling the boiler, and the device configuration can be simplified. In addition, there is no need for an expensive flow rate sensor, which reduces product costs. In addition, the outlet water temperature can be heated to the set temperature in an extremely short time.

[0022] According to the invention described in claim 2, the outlet temperature of the heated water can be set to a set temperature by controlling the flow rate and the heat of the burner. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a configuration diagram of a master boiler or each slave boiler constituting the boiler apparatus of the present invention. [Diagram 2] FIG. 2 is a diagram showing the electrical system configuration of the master boiler or each slave boiler. [Diagram 3] FIG. 2 is a diagram showing the connection configuration of the master boiler or each slave boiler. [Figure 4] FIG. 1 is a configuration diagram of a conventional hot water boiler. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 shows the configuration of each boiler (master boiler or slave boiler) A constituting the boiler system of the present invention.

[0025] In Fig. 1, reference numeral 1 denotes a water storage tank that stores water (boiler water) to be used as a heat transfer medium, and reference numeral 2 denotes a supply pipe that supplies boiler water to the water storage tank 1. Reference numeral 3 denotes a supply solenoid valve that is installed on the supply pipe 2 and switches between supplying water and stopping water, and is automatically controlled to open and close by the water supply function described later, so that a certain amount of water is always stored in the water storage tank 1.

[0026] Reference numeral 4 denotes a heat transfer medium flow pipe that communicates with the inside of the water storage tank 1 and circulates the boiler water in the water storage tank 1 to the outside of the water storage tank 1, and reference numeral 5 denotes a circulation pump for circulating the boiler water between the inside of the water storage tank 1 and the heat transfer medium flow pipe 4.

[0027] Reference numeral 6 denotes a temperature sensor attached to the heat transfer medium flow pipe 4 for measuring the boiler water temperature, and reference numeral 7 denotes a heat exchanger provided on the heat transfer medium flow pipe 4.

[0028] Reference numeral 8 denotes a burner for heating the water in the water storage can 1 from outside the water storage can 1, and reference numeral 9 denotes a fuel supply pipe for supplying fuel to the burner 8. Reference numeral 10 denotes a fuel control solenoid valve that is attached to the fuel supply pipe 9 and switches the supply of fuel to the burner 8 on and off.

[0029] Reference numeral 11 denotes an air supply pipe for supplying the air required for combustion to the burner 8, and reference numeral 12 denotes an air supply solenoid valve for switching the supply of air to the burner 8 on and off.

[0030] Reference numeral 13 denotes a water inlet pipe with the heat exchanger 7 disposed midway, and reference numeral 14 denotes a hot water outlet pipe connected to the water inlet pipe 13 via the heat exchanger 7. Reference numeral 15 denotes a temperature sensor attached to the hot water outlet pipe 14 for measuring the temperature of the hot water outlet pipe.

[0031] Reference numeral 16 denotes a controller for controlling various control devices that constitute boiler A, such as solenoid valves 3, 10, and 12 that constitute boiler A, a water level sensor (not shown) that detects the water level in the water tank 1, burner 8, and circulation pump 5, based on command signals from the operation panel described below and temperature information from temperature sensors 6 and 15.

[0032] Reference numeral 17 denotes a remote control that outputs command signals to the controller 16, and is operated for the purpose of controlling various control devices that constitute the boiler A, similar to the operation panel.

[0033] Fig. 2 is an electrical system configuration diagram explaining the electrical connection state of the controller 16 and its peripheral devices shown in Fig. 1. As shown in Fig. 2, the controller 16 is roughly composed of a control power supply unit 19 connected to an external power supply 18, a control unit 20 that operates by receiving a supply of control power from the control power supply unit 19, and an operation panel 21 that outputs a command signal to the control unit 20.

[0034] The operation panel 21 is provided with an operation section for an operator to input instruction information to be output to the control section 20, as well as various display sections, setting sections, and the like.

[0035] The control unit 20 is controlled and instructed not only by the operation panel 21 but also by a remote control 17. A separate external power source 22 is supplied to the remote control 17. The functions of the remote control 17 are generally similar to those of the operation panel 21 described above, but the remote control 17 is provided with additional switches and the like that enable the operation of multiple boilers A with one remote control, since multiple boilers A (only two are shown in FIG. 2) are connected to the remote control 17 as shown in FIG. 2.

[0036] When command signals and various setting signals are input from the operation panel 21 or the remote control 17, or various sensor information from the temperature sensors 6, 15 and the like connected to the sensor contacts 23 is input to the control unit 20, the control unit 20 executes various settings based on the input setting information, and controls the control device 24 and other boilers A according to the input command signals. Examples of the control device 24 include the solenoid valves 3, 10, and 12 shown in Fig. 1, a water level sensor (not shown) that detects the water level in the water storage tank 1, the burner 8, the circulation pump 5, and the like.

[0037] Next, the physical connection state of each boiler (master boiler, slave boiler) A in the boiler system of the present invention is shown in Fig. 3. As shown in Fig. 3, in the boiler system of the present invention, a plurality of boilers A (four in Fig. 3) having the configuration shown in Fig. 1 are connected in series.

[0038] In other words, as shown in Figure 3, a boiler apparatus A having the same configuration as the boiler A shown in Figure 1 is arranged, in which a water inlet pipe 13 is connected to the outlet pipe 14 shown in Figure 1, and another boiler apparatus A having the same configuration, in which a water inlet pipe 13 is connected to the outlet pipe 14 of the boiler apparatus A connected in this manner, is further connected.

[0039] In this way, by connecting multiple boilers A in series, the outlet water temperature is controlled to the set temperature by the multiple boilers A. In the present invention, one of the multiple boilers A is designated as the master boiler, and the others function as slave boilers. The master boiler controls the operation / stop of the slave boilers.

[0040] There are various methods for determining which boiler is the master boiler or the slave boiler, but for example, the boiler that is turned on first may function as the master boiler. In this way, when one boiler is set as the master boiler, the other boilers are automatically set and function as slave boilers.

[0041] Next, the operation of the boiler apparatus of the present invention will be described. First, in preparation for hot water demand, each boiler A shown in Fig. 3 stores a certain amount of boiler water in the water tank 1 when the power is turned on. At this time, as described above, for example, the boiler A that is turned on first functions as the master boiler A1, and the others function as slave boilers A2 to A4.

[0042] The water level in the water tank 1 of each boiler A1 to A4 is monitored by a water level sensor (not shown), which automatically switches the make-up solenoid valve 3 on and off. When the boiler water level becomes higher than the reference water level, the make-up solenoid valve 3 is closed to stop the water, and when the water level becomes low, the make-up solenoid valve 3 is opened to supply water to the water tank 1 (water supply function). The water supply function may be equipped with a function to determine that the water supply valve is abnormal if the low water level is detected continuously for a certain period of time or more.

[0043] In addition, the boiler water in the water tank 1 of each boiler A1 to A4 is heated to a predetermined temperature in advance in preparation for hot water supply demand. Specifically, by opening the fuel control solenoid valve 10, fuel is sent to the burner 8 through the fuel supply pipe 9, and by opening the air supply solenoid valve 12, air for combustion is sent to the burner 8.

[0044] Thereafter, the burner 8 is ignited and controlled to heat the boiler water in the water storage tank 1 to a predetermined temperature by the combustion of the burner 8. Whether or not the boiler water temperature has reached the predetermined temperature is determined by driving the circulation pump 5 to circulate the boiler water through the heat medium flow pipe 4, detecting the circulating boiler water temperature with the boiler water temperature sensor 6 attached to the heat medium flow pipe 4, and transmitting the detection result to the control unit 20 of the controller 16, whereby the control unit 20 grasps whether or not the boiler water temperature has reached the predetermined temperature.

[0045] The above preparations are carried out before a demand for hot water occurs, and when a demand for hot water actually occurs, the master boiler A1 first heats the outlet hot water temperature to the set temperature. There are two functions for controlling the outlet hot water temperature: the outlet hot water temperature control function and the boiler water temperature control function.

[0046] The outlet hot water temperature control function controls the flow rate of the circulation pump 5, and adjusts the outlet hot water temperature to the set temperature. The outlet hot water temperature is measured by a temperature sensor 15 for measuring the outlet hot water pipe temperature, and output to the control unit 20 of the controller 16. The control unit 20 receives this information and further controls the flow rate of the circulation pump 5 so that the outlet hot water temperature approaches the set temperature. By repeating the above operations, the outlet hot water temperature is adjusted to the set temperature.

[0047] The control method varies depending on the configuration of the control device. For example, when an inverter that drives the circulating pump 5 is provided, the input signal is the temperature information measured by the temperature sensor 15 for measuring the hot water outlet pipe temperature, and the output signal is the inverter frequency setting signal, so that PI control is performed.

[0048] In addition, when such an inverter is not provided, the input signal is the temperature information measured by the temperature sensor 15 for measuring the hot water outlet pipe temperature, and the output signal is the on / off signal of a switch (not shown) of the circulation pump 5.

[0049] The boiler water temperature control function controls the heat of the burner 8 and adjusts the boiler water temperature circulating in the heat transfer medium flow pipe 4 to a temperature that is a certain temperature higher than the set temperature. The boiler water temperature circulating in the heat transfer medium flow pipe 4 is detected by a boiler water temperature measuring temperature sensor 6, and measurement temperature information is output to the control unit 20 of the controller 16. The control unit 20, which receives this information, further controls the heat of the burner 8 so that the outlet water temperature approaches the set temperature. By repeating the above operations, the boiler water temperature is adjusted to the set temperature.

[0050] The control method varies depending on the fuel. For example, in the case of gas firing, PI control is used in which the input signal is the measured temperature information of the temperature sensor 6 for measuring the boiler water temperature, and the output signal is the opening setting signal (closed to fully open) of the fuel control solenoid valve 10.

[0051] In the case of oil firing, the input signal is temperature information measured by the temperature sensor 15 for measuring the temperature of the hot water outlet pipe, and the output signal is the on / off signal of the fuel control solenoid valve 10 (for example, a three-position on / off signal).

[0052] At this time, the fuel control solenoid valve 10 and the air intake solenoid valve 12 are linked to keep the air-fuel ratio constant.

[0053] Next, an example of the operation when the demand for hot water increases while the above operation is being performed will be described. When the demand for hot water increases, the boiler apparatus of the present invention first heats the outlet hot water temperature to a set temperature that meets the demand for hot water by the master boiler A1 alone.

[0054] If the master boiler A1 alone can heat the hot water outlet temperature to the set temperature, the slave boilers A2 to A4 do not operate. However, if the hot water outlet temperature is still below the set temperature even after the heating power command for the master boiler A1 reaches its upper limit, the present invention simultaneously operates the slave boilers A2 to A4 that were stopped, as shown in Figure 4, to instantly heat the hot water outlet temperature to the set temperature.

[0055] After the outlet hot water temperature reaches the set temperature, the number of operating slave boilers A2 to A4 is controlled to reduce the number of operating slave boilers A2 to A4, thereby controlling so that the outlet hot water temperature is maintained at the set temperature.

[0056] At this time, the outlet hot water temperature control of each boiler A1 to A4 is executed by the outlet hot water temperature control function and the boiler water temperature control function described above. Unlike the conventional technology, the outlet hot water temperature control using this function can heat the outlet hot water temperature to the set temperature in response to an increase in hot water demand without requiring a flow sensor, which reduces the cost of the device.

[0057] Furthermore, the present invention can heat the outlet water temperature to the set temperature in an extremely short time compared to a method in which the slave boilers A2 to A4 are started in sequence after the thermal power command of the master boiler A1 reaches its upper limit, thereby increasing the number of boilers (heat source devices) in operation.

[0058] By executing the above-mentioned outlet hot water temperature control, the inlet water in the water inlet pipe 13 shown in Figure 1 is heated to the set temperature by the heat exchanger 7 and is discharged from the hot water outlet pipe 14. The outlet hot water heated to the set temperature in this way meets the hot water demand of the user.

[0059] As described above, according to the boiler apparatus of the present invention, even when the demand for hot water increases, the flow rate of the boiler water circulation pump is controlled based on the temperature information measured by the temperature sensor for measuring the outlet hot water pipe temperature, so that an expensive flow rate sensor is not required.

[0060] Furthermore, by having one of the multiple boilers function as a master boiler, the other slave boilers can be controlled by that master boiler, eliminating the need to provide a separate control device for controlling the multiple boilers and simplifying the system configuration.

[0061] In the above description, an example was given in which the number of slave boilers was three, but it goes without saying that the scope of the present invention is not limited to this number. [Industrial Applicability]

[0062] The present invention is applicable to a boiler system consisting of multiple boilers. [Explanation of symbols]

[0063] 1 Water storage tank 2 supply pipe 3 Refill solenoid valve 4 Heat medium flow pipe 5 Circulation pump 6. Temperature sensor for measuring pipe water temperature 7 Heat exchanger 8 Burner 9 Fuel supply pipe 10. Fuel control solenoid valve 11 Air supply pipe 12 Air supply solenoid valve 13. Water Intake Pipe 14 Outlet pipe 15 Temperature sensor for measuring the temperature of the outlet pipe 16 Controller 17 Remote Control 18,22 External power supply 19 Control power supply section 20 Control section 21 Operation Panel 23 Sensor Contact 24 Control Equipment A Boiler (Master boiler A1, Slave boilers A2 to A4)

Claims

1. The boiler includes a boiler body for storing boiler water, a burner for heating the boiler water, a pump for circulating boiler water between the boiler body and a heat transfer medium flow pipe connected to the outside of the boiler body, a boiler water temperature measuring temperature sensor for measuring the boiler water temperature flowing in the heat transfer medium flow pipe, a heat exchanger attached to the middle of the heat transfer medium flow pipe, a water inlet pipe and a hot water outlet pipe connected via the heat exchanger, a hot water outlet pipe temperature measuring temperature sensor for measuring the water temperature in the hot water outlet pipe, and a controller for detecting measured temperature information from the boiler water temperature measuring temperature sensor and the hot water outlet pipe temperature measuring temperature sensor, and for controlling a heating command to the burner and the start / stop of the pump, and the temperature of the hot water flowing in the hot water outlet pipe is controlled by the plurality of boilers. one of the plurality of boilers functions as a master boiler and the others function as slave boilers, and the master boiler controls itself and the slave boilers so that the temperature of the hot water flowing through the hot water outlet pipe becomes a set temperature, and the control combines a hot water outlet temperature control that controls the flow rate of a boiler water circulating pump and a boiler water temperature control that controls the heat of a burner and adjusts the boiler water temperature to a certain temperature higher than the set temperature, and the master boiler alone heats the hot water to the set temperature, and if the master boiler alone cannot heat the hot water to the set temperature, all of the slave boilers are operated simultaneously to heat the hot water to the set temperature.

2. 2. The boiler apparatus according to claim 1, wherein the outlet hot water temperature control is performed by PI control when an inverter for driving a circulating pump is included as a component.

3. 3. The boiler apparatus according to claim 1, wherein the boiler water temperature control is a PI control when the supplied fuel is gas-fired, and a three-position on / off control of high output, low output, and off when the supplied fuel is oil-fired.

Images