JPS6158843B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a solar heat collection device in which a heat collector and a heat storage tank are connected in an annular manner via a circulation pump.

Conventionally, in this type of solar heat collecting device, the circulation pump is controlled to start or stop depending on the temperature difference between the water temperature in the heat collector and the water temperature in the lower part of the heat storage tank. In addition, various controls have been performed, such as control to prevent frequent starting and stopping of the circulation pump, antifreeze control, and control to protect the circulation pump. Furthermore, the configurations and combinations of the devices differ slightly depending on the installation location and customer requests, and various operations are required for each different device. For this reason, in the past, control devices were designed one by one and assembled with relay circuits and semiconductor logic circuits, or were designed to consist of a microprocessor (MPU), read-only memory (ROM), and random access memory (RAM). The solution has been to use a microcomputer and replace the ROM part, but with the former method, it takes a long time to redesign the relays and logic circuits, and there is little commonality among various devices, making it difficult to solve problems over time. Changing just one specification requires rethinking the entire complex logic, making it difficult to perform complex operations. In addition, the latter method is expensive because the microcomputer consists of an MPU, ROM, and RAM, and it is difficult to adopt it in cases where simple operations are required; must be checked for various combinations, and this work (debugging) is difficult.

The present invention has been made in view of the above-mentioned facts, and is designed to perform control such as circulation pump start/stop control, antifreeze control, and circulation pump protection control in a control device for a solar heat collector, which is often custom-made or whose specifications change frequently. Accurately carry out design work, and be able to respond to various orders without requiring complicated logic studies or debugging or changing hardware parts, thereby shortening design periods, lowering costs, and reducing errors. The basic configuration is a temperature difference thermometer that emits an output signal of 1 or 0 depending on the difference between the water temperature in the heat collector and the water temperature in the lower part of the heat storage tank, and a temperature difference thermometer that outputs an output signal of 1 or 0 depending on the temperature difference between the water temperature in the heat collector and the water temperature in the lower part of the heat storage tank, and the water temperature in the heat collector and the set value. An antifreeze thermostat that outputs an output signal of 1 or 0 by comparing the water temperature with the set value, a pump protection thermostat that outputs an output signal of 1 or 0 by comparing the water temperature in the upper part of the heat storage tank with a set value, and an output signal of 1 or 0. An operating switch that emits a 1 or 0 output signal, a delayed recovery timer that emits an output signal of 1 or 0, and a writable programmable timer that uses the output signals of these thermostats, the operating switch, and the timer as address inputs and issues the addressed data output. The feature is that it is equipped with a read-only memory (PROM) and an alarm, and controls the operation of the circulation pump and the operation of the timer and alarm according to the data output specified by the PROM. The PROM address is specified according to the combination of the output signals of the timer and the timer, and the operation of the circulation pump and the operation of the timer and alarm are accurately controlled based on the data at the specified address. Alternatively, it can be written or rewritten during installation to enable various complex operations in accordance with customer requests without relying on logic circuits or relay circuits.

Hereinafter, an embodiment in which the present invention is applied to a control device for a solar heat collector will be described based on the drawings.

FIG. 1 is a system diagram of a solar heat collecting device to which the present invention can be applied.
This is a heat storage tank that stores water as a heat medium that is heated using solar heat collected in the heat collector 1.
and the heat storage tank 3 are connected through an outgoing pipe 4 and a return pipe 5 as circulation paths. In the outgoing pipe 4, a circulation pump 6, a check valve 7 for preventing water hammer, and an outgoing pipe motor-operated valve 8 are sequentially installed near the heat storage tank 3, and the return pipe 5 is installed in the vicinity of the heat storage tank 3. An intake valve 9, an exhaust valve 10, and an expansion pipe 11 are connected to these parts, and a return pipe electric valve 12 is interposed near the heat storage tank 3. 13
is a cistern, which receives water overflow from the expansion pipe 11 and receives city water from the water supply pipe 14, replenishes water to the heat storage tank 3, and maintains the circulation system in a semi-sealed state. It is located at
A water pipe 15 is inserted into the lower part of the heat storage tank 3. 16 is a hot water outlet pipe led out from the upper part of the heat storage tank 3, and a three-way electric valve 17 is interposed in the middle, and the first
The inlet 171 and the outlet 173 communicate with each other so that hot water from the heat storage tank 3 is directly discharged,
A boil 19 is interposed in the branch pipe 18 that connects the outlet pipe 16 between the heat storage tank 3 and the first inlet 171 and the second inlet 172, and the second inlet 172 and the outlet 173 communicate with each other to store heat. Hot water from tank 3 is sent to boiler 19
The hot water is reheated and the hot water is dispensed.
Note that the area above the chain line indicates the outside of the machine room, and the area below the chain line indicates the inside of the machine room.

20 is a control device, which includes a boiler sensor 21 that detects the water temperature in the boiler 19, a heat storage tank sensor 22 that detects the water temperature in the lower part of the heat storage tank 3, and a heat collector 1.
Heat collector sensor 2 detects the water temperature of the heat collecting pipe on the outlet side of the
3, an antifreeze sensor 24 that detects the water temperature of the heat collection pipe in the middle part of the heat collector 1, and a protection sensor 25 that detects the water temperature in the upper part of the heat storage tank 3, and controls whether the heat collection pump 6 starts or stops. Opening/closing control of electric valves 8 and 12, switching control of three-way electric valve 17, and burner 2 of boiler 19
6 ignition control and alarm 27 operation control. Note that each sensor uses a thermistor or the like that converts temperature changes into analog values of electrical signals.

FIG. 2 shows a system diagram of the control device 20, in which the temperature measurement values from each sensor are converted into analog electrical signals by a hot water thermometer 28 as a converter,
29, temperature difference thermometer 30, antifreeze thermometer 31, excessive heat collection prevention thermometer 32, and pump protection thermometer 33 are respectively input, and hot water thermometers 28 and 29 are input to setting device 3.
The other thermometers 30 to 33 compare in magnitude with a predetermined fixed setting signal, and output an output signal of 1 or 0, respectively. Each thermostat is composed of an ordinary electronic thermocircuit consisting of a resistor bridge circuit including each sensor on one or two sides, a comparator such as an operational amplifier, and a feedback resistor for differential setting. For example, the hot water thermostat 28 emits an output signal of 0 when the water temperature in the boiler 19 is higher than the setting value of the setting device 24 (for example, variable from 30 to 80°C), and outputs an output signal of 1 when it is lower. It emits an output signal of 0 when the water temperature is higher than the set value of the setting device 34 and 1 when it is lower than the set value. For example, if the temperature is higher than 7℃),
It emits an output signal of 1 until this temperature difference falls below a predetermined value (2 degrees Celsius as an example), and 0 otherwise.
When the water temperature in the middle of the heat collector 1 falls below a predetermined value (for example, 3°C), the antifreeze thermometer 31 turns to 1 until the water temperature reaches a predetermined value (for example, 7°C) or higher, and to 0 otherwise.
When the water temperature in the upper part of the heat storage tank 3 reaches a predetermined value (for example, 92°C) or more, the overheat collection prevention thermometer 32 outputs an output signal of
In other cases, an output signal of 0 is issued, and when the water temperature in the upper part of the heat storage tank reaches a predetermined value (for example, 95°C) or higher, the pump protection thermometer In this case, an output signal of 0 is generated.

35 is the output signal of each thermostat 28 to 33 and the on/off (1 or 0) signal of the operation switch 36;
The output signal (1 or 0) of the delayed return type timer 37 is supplied as an address input to input terminals A0 to A7, and the data stored at a specified address corresponding to the address input is sent to output terminals D0 to D5. This is a programmable read-only memory (PROM) that generates a memory, and in this example, the commercially available MB8516 from Fujitsu or μ
It uses an E (erasable) PROM that can be freely written and rewritten, such as the PD2716. The data output (1 or 0) issued to the output terminals D0 to D5 is transmitted through a relay (not shown), etc. to command the ignition of the burner 26, the switching command of the three-way electric valve 17, and the operation command of the heat collecting pump 6. , an opening/closing command for the outbound pipe electric valve 8 and the return pipe motorized valve 12, an operation command for the alarm 27, and an operation command for the timer 37. That is, data may be determined for each address of the PROM 35 so that operating conditions suitable for each address input and in accordance with the customer's requests can be obtained, an example of which is shown in FIG.

The operation of this embodiment will now be explained with reference to FIG. First, as shown in the operation example, input terminals A2 and A7 of PROM35 are set to 1, input terminals A0, A1, and A
When there is an address input of 0 in 3 to A6, a data output of [0, 1, 1, 0, 0, 1] is issued to the output terminals D0 to D5. In such a case, there is solar radiation, and there is a temperature difference where the temperature sensed by the heat collector sensor 23 is higher than the temperature sensed by the heat storage tank sensor 22 by a predetermined value or more, and the temperature difference is in a state where heat collection is possible. The thermostat 30 is emitting an output signal of 1, the other thermos are emitting an output signal of 0, and of course,
The operation switch 36 is turned on. At this time, the burner 26 is not ignited, and the three-way electric valve 1
7 has a first inlet 171 and an outlet 173 communicating with each other, and hot water from the heat storage tank 3 is directly tapped from the hot water tap 16 without going through the boiler 19. or,
The heat collecting pump 6 operates when the outgoing pipe electric valve 8 and the return pipe motorized valve 12 are opened, and water circulates between the heat storage tank 3 and the heat collector 1 via the outgoing pipe 4 and the return pipe 5, and the solar heat is removed. Hot water is stored in the heat storage tank 3 using heat collection.
Furthermore, the timer 37 operates due to the 1 output from the output terminal D5, and generates an output signal of 1, which is sent to the input terminal A7.
Therefore, the address input of the PROM 35 changes as in the operation example, but the data output does not change. During this heat collection operation, when there is no solar radiation and the temperature difference between the heat collector sensor 23 and the heat storage tank sensor 22 becomes smaller and becomes less than a predetermined value, the temperature difference thermometer 30 emits an output signal of 0, and the address input of the PROM 35 becomes It changes as shown in the operation example. At this time, the output terminal D5 changes to 0 output and the timer 37 is commanded to cancel its operation, but the output signal of the timer 37 is held in the state of 1 for a certain period of time and the heat collecting operation continues as it is. Then, when the timer 37 returns and the output signal becomes 0, the heat collection pump 6 is stopped as in the operation example, and both the electric valves 8 and 12 are closed. In this way, even if the temperature difference thermometer 30 issues a 0 signal, the heat collecting operation continues for a certain period of time, so once the heat collecting pump 6 is operated, it will always be operated for a period longer than the return delay time of the timer 37. Can be turned on and off frequently without being damaged. Of course, if the temperature difference thermostat 30 again issues an output signal of 1 within the recovery time of the timer 37, the timer 37 is reset and the heat collecting operation continues.

During the heat collection operation described above, when the water temperature in the heat storage tank 3 rises and the temperature sensed by the protection sensor 25 becomes, for example, 92 degrees Celsius or more, an overheat collection state occurs, the overheat collection thermometer 32 is activated as shown in the operation example. The address input changes by issuing an output signal. In this case, since the output of the output terminal D2 becomes 0, the electric valves 8 and 12 are closed and the operation of the heat collection pump 6 is stopped, preventing the temperature rise in the heat storage tank 3 and preventing an accident during hot water tapping. At the same time, it prevents boiling from occurring in the circulation system. In the unlikely event that there is a failure in the control contacts (not shown) of the heat collecting pump 6 and the heat collecting pump 6 does not stop even though a stop command has been issued to the heat collecting pump 6, the protection sensor 25 When the detected temperature reaches 95°C, the pump protection thermostat 33 becomes an output signal, and the address input becomes as shown in the operation example. At this time, the data outputs of the output terminals D0 to D5 are [0, 1,
0, 0, 1, 1], and the alarm 27 is activated by the 1 output from the output terminal D4 to notify the manager of the abnormality. The manager can manually turn off the power to the heat collecting pump 6 to perform inspection, and prevents water with a temperature higher than the permissible temperature from being supplied to the heat collecting pump. Then, as hot water is released, new city water is supplied to the heat storage tank 3 from the water pipe 15, and when the temperature sensed by the protection sensor 25 falls to a predetermined value (for example, 85°C), the overheat collection prevention thermometer 32 and the pump protection thermometer are activated. The output signal of 33 becomes 0, and heat collection operation becomes possible.

Further, as in the operation example, when the temperature sensed by the antifreeze sensor 24 provided in the center of the heat collector 1 drops below a predetermined value from the state where the heat collection operation is stopped, and there is a risk of freezing, The antifreeze thermostat 31 emits an output signal of 1, the address input of the PROM 35 becomes as shown in the operation example, and the data outputs of the output terminals D0 to D5 become [0, 1, 1, 0, 0, 0] and are collected. As the heat pump 6 operates, the electric valves 8 and 12 open, and the hot water in the lower part of the heat storage tank 3 is supplied to the heat collector 1 to prevent freezing. When the temperature sensed by the antifreeze sensor 24 reaches a predetermined value or higher and there is no danger of freezing, the state returns to the operation example, the operation of the heat collecting pump 6 is stopped, and the electric valves 8 and 12 are closed.

In each of the above operation sequences, when the temperature sensed by the heat storage tank sensor 22 becomes lower than the set value of the setting device 34,
The output signal of the hot water thermostat 29 becomes 0 and is input to the input terminal A1, and at this time, the output terminal D1 outputs a 0 output so that the second inlet 172 and the outlet 173 of the three-way electric valve 17 communicate with each other. do. Then, only when the temperature sensed by the hot water sensor 21 is lower than the set value of the setting device 34 and the hot water thermostat 28 is emitting an output signal of 1, the output terminal D0 becomes 1 output, the burner 26 is ignited, and the heat storage tank 3 is heated. Hot water boiler 19
The hot water is reheated to the set value and used for hot water.

FIG. 4 shows a system diagram of another solar heat collector to which the present invention can be applied. Parts corresponding to those in FIG. A drain pipe 39 with a drain motor operated valve 38 interposed therebetween is connected to the middle of the drain pipe 39.
8 upstream side and the middle of the return pipe 5 are connected by a bypass pipe 41 in which a check valve 40 is interposed. Such a heat collecting device is particularly in demand in cold regions, and when the antifreeze sensor 24 detects a low temperature below a predetermined value, the electric drain valve 38 is opened without operating the heat collecting pump 6. The water in the heat collector 1 outside the machine room, the outgoing pipe 4, and the return pipe 5 is discharged from the drain pipe 39 to reliably prevent freezing without using hot water in the heat storage tank 3. It is. The control device 20 shown in FIG. 2 can be used as is, and the electric drain valve 38 can be used as it is.
It is only necessary to perform control according to the output of the output terminal D4 of the PROM35, and as shown in the operation example' in Figure 3, when there is an input of 1 to the input terminal A3, an output of 0 is output to the output terminal D2, and 1 is output to the output terminal D3. All you need to do is rewrite the data corresponding to the address input so that it will be issued.

In the case of the above-mentioned MB-8516, there are actually 12 input terminals and 8 output terminals, and it is possible to perform even more complex operations. Furthermore, by using an EEPROM that can be written and erased electrically, it is possible to rewrite part of the data corresponding to the address input after listening to the customer's wishes at the time of installation. Further, the PROM referred to in the present invention may be a write-only bipolar fuse type in addition to an EPROM or an EEPROM that can be written and erased.

Since the present invention is configured as described above, it is possible to accurately control the operation of the circulation pump and the operation of the timer and alarm, thereby efficiently collecting solar heat, preventing freezing in the circulation path, and further can protect the circulation pump, and can be used to control versatile solar heat collectors without building complex logic or relay circuits or making any changes to the hardware, just by considering the input/output conditions of the PROM. It is possible to configure the device, and if used as a control device for solar heat collectors that are often custom-made or have many design changes, it will shorten the design period and reduce costs, and it will also be possible to select the operation according to the customer's requests. etc. are useful.

[Brief explanation of the drawing]

Figure 1 is a system diagram showing an example of a solar heat collector to which the present invention can be applied, Figure 2 is a system diagram of a control device for a solar heat collector which is an embodiment of the present invention, and Figure 3 is a system diagram showing an example of a solar heat collector that is an embodiment of the present invention. An explanatory diagram showing an example of the input/output conditions of the PROM used in the figure, and FIG. 4 is a system diagram showing another example of a solar heat collector to which the present invention is applicable. 1... Heat collector, 3... Heat storage tank, 6... Circulation pump, 27... Alarm, 30... Differential temperature thermometer, 31
...Anti-freeze thermo, 33...Pump protection thermo, 35...PROM, 36...Operation switch, 3
7...Timer.

Claims (1)

[Claims] 1. In a control device for a solar heat collection device in which a heat collector and a heat storage tank are connected in a circular manner via a circulation pump, 1 or Compare the temperature difference thermometer that emits an output signal of 0 with the water temperature of the collector and the set value to determine whether it is 1 or 0.
an antifreeze thermostat that emits an output signal of 1; a pump protection thermostat that emits an output signal of 1 or 0 by comparing the water temperature in the upper part of the heat storage tank with a set value; and an operation switch that emits an output signal of 1 or 0; Or a delayed return type timer that emits an output signal of 0, and a writable programmable read-only memory (PROM) that uses the output signals of these thermostats, operation switches, and timers as address inputs and outputs the addressed data output. , equipped with an alarm,
A control device for a solar heat collector, characterized in that it controls the operation of a circulation pump and the operation of a timer and alarm in accordance with data output designated by a PROM address.