CN104146609A - Multi-temperature direct water dispenser based on PLC (programmable logic controller) control - Google Patents

Abstract

The invention discloses a multi-temperature direct drinking water dispenser based on PLC control, which is mainly composed of a water storage tank, a heating tank, a heat exchanger, a PLC control system and the like. The water in the heating box is introduced from the water storage tank, and the tap water is preheated into the water storage tank through the heat exchanger. At the same time, the ratio of boiling water and warm water at the water outlet can be adjusted to realize the intelligent adjustment of the water temperature of the single-chip microcomputer. The effluent water left over in the heat exchanger overnight is drained before starting up to ensure the health and safety of drinking water. The invention can obtain direct drinking water of multiple temperatures at one time according to the demand, shortens the time before drinking water, and has good product practicability. At the same time, since the raw water is preheated by a heat exchanger before boiling, the heating time and power consumption can be greatly saved. The multi-temperature direct-drinking water dispenser based on PLC control of the present invention is suitable for schools, restaurants, kitchens and other occasions where there is a large demand for multi-temperature direct-drinking water.

Description

A multi-temperature direct drinking water dispenser based on PLC control

Technical field:

The invention relates to a novel water dispenser, in particular to a multi-temperature direct drinking water dispenser based on PLC control.

Background technique:

Water is an indispensable drink in people's life, and the use of modern water dispensers has entered every aspect of people's lives. The traditional water dispenser has only one heating water tank, and only boiling water can be obtained from the water dispenser. It takes a lot of time to reach the drinking temperature. At the same time, a large amount of heat is dissipated in the cooling process, which does not meet the basic requirements of modern electrical appliances for energy saving.

In order to solve the problem that the water dispenser cannot obtain direct drinking water, the main solutions adopted by the new water dispenser include two methods: heating at a fixed temperature and mixing hot and cold water. Constant temperature heating mainly consists of heat preservation water and instant hot water. Heat preservation water outlet, as existing patent CN103445680A, is generally controlled by common circuit, makes heater work in the specified temperature range. Although constant temperature heating can obtain a general range of water temperature, the existing control method is unreliable, and the single water output is limited, so it is difficult to meet the situation of large water demand and high temperature demand. Instantly hot outlet water such as CN201243951Y has poor temperature control effect, slow water outlet, high working power, poor reliability, and does not meet energy-saving requirements. The traditional method of mixing hot and cold water directly introduces raw water into boiling water. Although the water temperature can be lowered to a temperature suitable for the human body, studies have shown that it will cause a large number of bacteria to multiply and cause long-term damage to human health. Patent CN102920334A has improved the traditional mixing method, but due to the lack of measurement and control methods, it is difficult to control the water temperature, and it is difficult for the heat exchange device to achieve the theoretical cooling effect. Patent CN103622554A has improved this scheme and solved some deficiencies. However, the water dispenser device disclosed in this patent is extremely complicated, the reliability cannot be guaranteed, the production cost is high, and it is difficult to promote it in the market.

Therefore, in order to solve the problems of existing water dispensers such as extensive control systems, extensive cooling methods, poor water quality safety, and imperfect economic and energy saving, it is necessary to propose a more economical and practical energy-saving water dispenser.

Invention content:

The purpose of the present invention is to provide a multi-temperature direct-drinking water dispenser based on PLC control, which uses a PLC control system to control the flow rate, aiming at the problems of existing water dispensers such as extensive control systems and cooling methods, poor water quality and safety, and imperfect economy and energy saving. , Aviation plate-fin heat exchanger for heat recovery, a water dispenser that can obtain drinking water of various temperatures with a single machine.

The present invention adopts the following technical scheme: a multi-temperature direct-drinking water dispenser based on PLC control, which includes a water storage tank, a heating tank and a heat exchanger in which the water in the water storage tank flows into it, and a heater inside. The multi-temperature direct drinking water dispenser also includes a DC motor and a PLC control system. The heat exchanger is provided with a heat exchanger hot water inlet, a heat exchanger preheating cold water outlet, a heat exchanger cold water inlet and a heat exchanger heat Water outlet, the heating tank is provided with a water outlet pipeline, and a three-way valve is installed on the water outlet pipeline, and the three-way valve includes an inlet, an outlet and a diversion port connected with the water outlet pipeline. The outlet is connected with the first shunt pipeline, and the diversion port of the three-way valve is connected with the second shunt pipeline, and a Hall type turbine flow sensor is sequentially installed on the first shunt pipeline from the direction away from the heating tank. And the third valve, the other end of the second branch pipeline is connected to the hot water inlet of the heat exchanger, the cold water inlet of the heat exchanger is connected to the external tap water, and the water flowing out of the cold water outlet of the heat exchanger is preheated Into the water storage tank, the hot water outlet of the heat exchanger is connected with a third pipeline, and a Hall-type turbine flow sensor and a fourth valve are sequentially installed on the third pipeline from the direction away from the heating tank, wherein The PLC control system is set between the third valve and the fourth valve. The DC motor includes a DC water boiling motor and a heat exchange warm water motor. The DC water boiling motor is connected with the third valve and the PLC control system. The heat exchange warm water motor is connected with the fourth valve and the PLC control system, the end of the first shunt pipeline passes through the Hall type turbine flow sensor and the third valve, and the end of the third pipeline passes through the Hall type turbine flow sensor. The sensor and the fourth valve intersect, and the water outlet of the water dispenser is formed at the intersection of the first branch pipeline and the third pipeline. Several faucets with different temperatures are installed at the water outlet of the water dispenser.

Further, the PLC control system includes a single-chip microcomputer, and the Hall-type turbine flow sensor is connected to the single-chip microcomputer to convert the flow velocity flowing through the Hall-type turbine flow sensor into a current frequency signal and transmit it to the single-chip microcomputer.

Further, a first pipeline is provided between the water storage tank and the heating tank, and a first valve is installed on the first pipeline to control the flow of water in the water storage tank and the heating tank.

Further, a control valve is installed below the heat exchanger, and the multi-temperature direct drinking water dispenser also includes a DC motor connected with the control valve and the PLC control system.

Further, the heat exchanger is an aviation plate-fin heat exchanger.

The present invention has following beneficial effects:

(1). The present invention adopts PLC control to ensure the reliability of the work. By changing the water flow ratio to control the temperature of drinking water, a single machine can obtain direct drinking water of various temperatures, install multiple faucets, and change the temperature without replacing parts, which is very practical;

(2). Through the aviation plate-fin heat exchanger, the heat dissipated by hot water cooling can be recycled, and the heat recovery can be used to reduce the heating amount, which is energy-saving, environmentally friendly and economical;

(3). The water dispenser can be automatically turned on and off through the circuit setting, which reduces the loss of standby and heat preservation, and drains the overnight water before turning on to ensure the safety and health of the water quality;

(4). The present invention is suitable for schools, restaurants, kitchens, etc. where there is a large demand for multi-temperature direct drinking water. At the same time, the technology of the present invention can be used to transform existing ordinary water dispensers, with reliable technology and low cost.

Description of drawings:

Fig. 1 is the structural principle diagram of the multi-temperature direct-drinking water dispenser based on PLC control of the present invention.

Figure 2 is a structural diagram of an aviation plate-fin heat exchanger.

Figure 3 is the wiring diagram of the DC motor and the pins of the microcontroller.

Fig. 4 is the control flowchart of PLC system.

Figure 5 is a connection diagram between the Hall type turbine flow sensor and the PLC control system.

in:

1-water storage tank; 2-heating tank; 3-hot water inlet of heat exchanger; 4-preheating cold water outlet of heat exchanger; 5-heat exchanger; 6-cold water inlet of heat exchanger; 7-PLC control system; 8 - water dispenser outlet; 9 - heat exchanger hot water outlet; 10 - control valve; 11 - first pipeline; 12 - first valve; 13 - water outlet pipeline; 14 - second valve (three-way valve); 15-the first distribution pipeline; 16-the second distribution pipeline; 17-the third valve; 18-the second pipeline; 19-the third pipeline; 20-the fourth valve.

Detailed ways:

Please refer to Fig. 1, the multi-temperature direct-drinking water dispenser based on PLC control of the present invention includes a water storage tank 1, a heating tank 2 with a heater inside, a heat exchanger 5 and a PLC control system 7.

The water storage tank 1 and the heating tank 2 are connected through a first pipeline 11, and a first valve 12 for controlling water circulation in the water storage tank 1 and the heating tank 2 is installed on the first pipeline 11. A water outlet pipeline 13 is arranged in the heating box 2, and a second valve 14 is installed on the water outlet pipeline 13, wherein the second valve 14 is a three-way valve, and the inlet of the second valve 14 is connected with the water outlet pipeline 13 , the outlet of the second valve 14 is connected with the first diversion pipeline 15 , and the reversing port of the second valve 14 is connected with the second diversion pipeline 16 . Wherein the first shunt pipeline 15 is installed with a Hall type turbine flow sensor (not shown) and a third valve 17 successively from the direction away from the heating box 2, and the other end of the second shunt pipeline 16 is connected with the heat exchanger. Hot water inlet 3 connections. The heat exchanger 5 also includes a heat exchanger cold water inlet 6 and a heat exchanger preheating cold water outlet 4, wherein the heat exchanger cold water inlet 6 is connected with external tap water, and the water flowing out of the heat exchanger preheating cold water outlet 4 passes through the first The second pipeline 18 flows into the water storage tank 1 . The water that flows out from the hot water outlet 9 of the heat exchanger flows out through a third pipeline 19, on which a Hall-type turbine flow sensor (not shown) and a first Four valves 20, wherein the PLC control system 7 is set between the third valve 17 and the fourth valve 20. Wherein the end of the first shunt line 15 intersects after passing through the Hall type turbine flow sensor and the third valve 17 and the end of the third pipeline 19 after passing through the Hall type turbine flow sensor and the fourth valve 20, at the first The water outlet 8 of the water dispenser is formed at the intersection of the diversion pipeline 15 and the third diversion pipeline 19, and several faucets with different temperatures are installed at the water outlet 8 of the water dispenser.

The PLC control system takes the single-chip microcomputer as the core, and uses the triode to build the H-bridge to realize the drive control of the high-power DC motor. The present invention includes three DC motors, which are respectively a DC boiling water motor connected to the third valve 17 , a heat exchanging warm water motor connected to the fourth valve 20 , and a DC motor connected to the control valve 10 . Taking a DC motor as an example to illustrate how the PLC control system controls the motor, as shown in Figure 3, the P10 pin of the microcontroller outputs high and low levels to control the positive and negative rotation of the motor, and the P11 outputs PWM waveforms to control the motor speed, and then the control of the motor can be realized. Precise control of DC motors. A wiring diagram of a DC motor and the pins of a single-chip microcomputer is shown in Figure 3.

Fig. 5 has provided the connection figure of a kind of Hall type turbine flow sensor and PLC control system, and wherein when boiling water directly flows to the Hall type turbine flow sensor through the first shunt pipeline 15, and warm water in the heat exchanger 5 is exchanged When the hot water outlet 9 of the heater flows to the Hall type turbine flow sensor through the third pipeline 19, due to the impact of the water flow, the turbines in the Hall type turbine flow sensor are respectively driven to rotate to obtain the turbine speed, and at the same time the Hall type turbine flow sensor The rotation speed is converted into a current frequency signal and transmitted to the PLC control system 7. The flow sensor in the present invention is a Hall type turbine flow sensor.

The control flow chart of PLC control system is as Fig. 4, and water velocity signal is converted into electric current frequency signal by Hall type turbine flow sensor and is sent to single-chip microcomputer, simultaneously input required drinking water temperature (PLC control system of the present invention) on PLC control system There are four temperature buttons on the top, respectively 100°C, 95°C, 87°C, 40°C), and the ratio of boiling water to warm water is determined by the set temperature. Because the single-chip microcomputer control is a sampling control, it calculates the control amount according to the deviation between the flow rate collected by the flow sensor and the set value. If the difference between the set value and the collected amount is greater than zero, the motor rotates forward and the valve is opened; the set value When the difference with the collection amount is less than zero, the motor reverses and the valve is closed. Before the main program makes a series of program calls, initialize the system, and then judge the switch state program to respond; then perform a series of subroutines, perform A/D conversion and PID calculation, and use the results to control the third The valve 17 and the fourth valve 20 open the size and time, thereby adjusting the flow of the first diversion pipeline 15 and the third pipeline 19, achieving the purpose of mixing boiling water and warm water, and obtaining water at the temperature required by the drinker.

During work, the heater in the heating box 2 boils water and then enters the water outlet pipeline 13, while a part of water enters the hot water inlet 3 of the heat exchanger through the second branch pipeline 16. The cold water inlet 6 of the heat exchanger is connected with tap water, and the normal temperature tap water enters the heat exchanger and is preheated, and the preheated cold water outlet 4 of the heat exchanger flows out, and enters the water storage tank 1 through the second pipeline 18 by virtue of the tap water pressure. When the water in the heating tank 2 is insufficient, the first valve 12 between the water storage tank 1 and the heating tank 2 is opened, and the preheated water enters the heating tank 2 through the first valve. The multi-temperature direct drinking water dispenser based on PLC control of the present invention uses the heat exchanger 5 to transfer the heat cooled by the boiling water to the tap water to be heated, which not only recovers the dissipated heat, but also preheats the tap water, greatly reducing the heating of the heating box quantity.

The current water dispenser can be equipped with an automatic switch. When starting up, the PLC control system 7 sends a low-level signal to the DC motor connected to the control valve 10 at the lower end of the heat exchanger 5, so that the motor rotates counterclockwise to open the control valve for 1 minute, and the heat exchange After the water in the device is emptied overnight, it is closed, water is filled in the water storage tank and the heating tank, and the heating tank starts to heat up. The opening time of the control valve can be determined by the capacity of the heat exchanger and the cross-sectional area of the control valve. The water dispenser heat exchanger generally uses a relatively mature plate-fin heat exchanger in the aviation field. The structure of the plate-fin heat exchanger is shown in Figure 2. The structure of the heat exchanger adopts a partitioned compact type, with two processes on the hot side and one process on the cold side to ensure the best heat exchange effect. The working parameters of the heat exchanger can be determined according to the water output of the water dispenser and the minimum design temperature of the water output.

The pressure required for the hot water inlet 3 of the heat exchanger can be provided by the height. The height difference between the hot water inlet of the heat exchanger and the water outlet of the water dispenser is about 1.2m to ensure the pressure supply. The cold water inlet of the heat exchanger is determined by the tap water pressure ( about 0.14Mpa) to provide.

The multi-temperature direct-drinking water dispenser based on PLC control of the present invention can ensure the reliability of work by adopting PLC control. By changing the water flow ratio to control the drinking water temperature, a single machine can obtain direct drinking water of various temperatures, install multiple faucets, and change the temperature without replacing parts, which is very practical. Through the aviation plate-fin heat exchanger, the heat dissipated by hot water cooling can be recycled, and the heat recovery can be used to reduce the heating amount, which is energy-saving, environmentally friendly and economical. The water dispenser can be automatically turned on and off through the circuit setting, which reduces the loss of standby and heat preservation, and drains the overnight water before turning on to ensure the safety and health of the water quality.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, some improvements can also be made without departing from the principle of the present invention, and these improvements should also be regarded as the invention. protected range.

Claims (5)

1. A multi-temperature direct-drinking water dispenser based on PLC control, which includes a water storage tank (1), a heating box (2) in which the water in the water storage tank (1) flows into and is provided with a heater and a replacement Heater (5), characterized in that: the multi-temperature direct drinking water dispenser also includes a DC motor and a PLC control system (7), and the heat exchanger (5) is provided with a heat exchanger hot water inlet (3 ), heat exchanger preheating cold water outlet (4), heat exchanger cold water inlet (6) and heat exchanger hot water outlet (9), said heating box (2) is provided with outlet pipeline (13), in A three-way valve (14) is installed on the water outlet pipeline (13), and the three-way valve (14) includes an inlet, an outlet and a diversion port connected with the water outlet pipeline (13), and the three-way valve (14) The outlet of the three-way valve (14) is connected to the first branch pipeline (15), and the diversion port of the three-way valve (14) is connected to the second branch pipeline (16). A Hall-type turbine flow sensor and a third valve (17) are sequentially installed in the direction of the box (2), and the other end of the second shunt pipeline (16) is connected to the hot water inlet (3) of the heat exchanger, The cold water inlet (6) of the heat exchanger is connected to the external tap water, the water flowing out of the preheated cold water outlet (4) of the heat exchanger flows into the water storage tank (1), and the hot water outlet (9) of the heat exchanger ) is connected with a third pipeline (19), on which a Hall-type turbine flow sensor and a fourth valve (20) are installed in sequence from the direction away from the heating box (2) on the third pipeline (19), wherein The PLC control system (7) is arranged at the position between the third valve (17) and the fourth valve (20), the DC motor includes a DC boiling water motor and a heat exchange warm water motor, and the DC boiling water motor and the third valve (17) is connected with the PLC control system, the heat exchange warm water motor is connected with the fourth valve (20) and the PLC control system, and the end of the first shunt pipeline (15) passes through the Hall type turbine flow sensor And the end of the third valve (17) and the third pipeline (19) intersects after passing through the Hall type turbine flow sensor and the fourth valve (20), in the first shunt pipeline (15) and the third The intersection of the pipelines (19) forms a water outlet (8) of the water dispenser, and the water outlet (8) of the water dispenser is equipped with several faucets that discharge different temperatures. 2. The multi-temperature direct-drinking water dispenser based on PLC control as claimed in claim 1, wherein the PLC control system includes a single-chip microcomputer, and the Hall type turbine flow sensor is connected with the single-chip microcomputer and then flows through the Hall. The flow velocity of the type turbine flow sensor is converted into a current frequency signal and then transmitted to the microcontroller. 3. The multi-temperature direct-drinking water dispenser based on PLC control as claimed in claim 2, characterized in that: a first pipeline (11) is arranged between the water storage tank (1) and the heating tank (2). The first valve (12) for controlling the circulation of water in the water storage tank (1) and the heating tank (2) is installed on the first pipeline (11). 4. The multi-temperature direct drinking water dispenser based on PLC control as claimed in claim 3, characterized in that: a control valve (10) is installed below the heat exchanger (5), and the multi-temperature direct drinking water The machine also includes a DC motor connected with the control valve (10) and the PLC control system (7). 5. The multi-temperature direct drinking water dispenser based on PLC control according to any one of claims 1-4, characterized in that: the heat exchanger (5) is an aviation plate-fin heat exchanger.