Development and design of drinking fountain scheme
The water dispenser is a device that heats and cools bottled water (distilled water, pure water, mineral water, etc.) or domestic water treated by a purification device, or provides the human body for drinking at the original water temperature. With the continuous development and innovation of drinking fountain technology, high-end drinking fountains have added functions such as antibacterial, ozone disinfection, and fluorine-free refrigeration on the basis of traditional drinking fountains.
1. The working principle of the drinking fountain solution
Heating principle: The heating system is divided into internal heating and external heating. The internal heating type uses a stainless steel electric heating tube to directly act on the water in the hot tank to heat the water; the external heating type uses a heating coil to heat the outside of the hot tank with an insulation layer to reduce heat loss. In contrast, the internal heating has high thermal efficiency and low power consumption, but the surface of the heating layer is easy to scale and is not easy to clean; the external heating has large heat loss, high noise, but less scale and less damage to the heating element.
Principle of refrigeration: refrigeration is divided into compressor refrigeration and electronic refrigeration.
(1) Compressor refrigeration: When the compressor is refrigerating, it uses the working principle of the refrigerant to absorb heat and condense and release heat for refrigeration, which is divided into two methods: external refrigeration and internal refrigeration. The compressor refrigeration system is mainly composed of the compressor, condenser, filter, capillary tube, evaporator and other five main components connected by pipes, which is a closed system. The system is filled with refrigerant, which is generally R12 (fluorine-containing) or R134a (fluorine-free).
(2) Electronic refrigeration: Electronic refrigeration mainly achieves the purpose of refrigeration through electronic refrigeration chips. The electronic refrigeration chip is composed of two ceramic substrates with 127 pairs of semiconductor crystal grains in between. During operation, the ceramic substrate on one side generates heat and the other side absorbs heat. The heat-absorbing end is connected with the refrigerating rod in the cooler to achieve the purpose of refrigeration; the heat-emitting end is connected with the heat sink, and the heat is taken away by the fan.
Antibacterial principle: Antibacterial agents are mainly realized by a formula that prevents microbial degradation. This formula is an additive that has the biological function of avoiding pathogenic microorganisms. The antibacterial agent is composed of a positively charged group, which neutralizes the negatively charged bacteria, ruptures the bacterial cell wall, overflows the cytoplasm, causes the bacteria to die, and achieves the purpose of sterilization.
Principle of ozone disinfection: Ozone is an unstable gas, which is soluble in water but not highly soluble. It is a strong oxidant and disinfectant. If the disinfection switch of the water dispenser is turned on, the disinfection components will generate ozone gas through the ozone generator and diffuse into the disinfection cabinet. When ozone reaches a certain concentration, it can kill microorganisms in a short time and inhibit the growth of bacteria. Principle of Violet Anti-Virus: Violet anti-virus technology has been applied to water disinfection for more than 100 years. The disinfection efficiency is very high and it is also an environmentally friendly technology. The first domestic Ziguang drinking fountain was born in Qidi Group in January 2004, bringing a technological breakthrough in the "anti-secondary pollution" of drinking fountains.
The principle of purple light disinfection: It is disinfected by irradiating water or air with strong ultraviolet rays generated by a specially designed high-efficiency, high-intensity and long-life C-band ultraviolet generator. It can make various pathogen cells and tissues in water or air. The DNA structure is destroyed and loses activity, so as to achieve the purpose of sterilization. Compared with the traditional chlorine dioxide method, ozone method, and membrane filtration method, the advantages of ultraviolet disinfection technology are: no chemical substances are added, no toxic substances are generated or left in the water, and the operation is safe.
Second, the design ideas of the new type of drinking fountain
Traditional drinking fountains have many problems, including safety hazards, health, and energy saving. When the water dispenser is dry without water, the water dispenser will be burnt in the slightest, and it will cause a fire in severe cases; children curiously press the water button to play and cause scalds; the water in the hot water tank is repeatedly heated to form a thousand boiling water, which will cause damage to the human body Hazard: After the water dispenser is heated, if people forget to cut off the power, it will always be in a state of power consumption, causing energy waste. In addition, there are also problems such as long waiting time for heating and manual operation of the power switch and water outlet switch. From the perspective of safety, health, energy saving, convenience, humanity and ease of use, the design of an instant-heat smart drinking fountain with perfect functions.
A pyroelectric infrared sensor is installed on the drinking fountain to automatically detect whether someone is approaching the drinking fountain. The photosensitive sensor detects whether it is daytime or night to determine whether the welcome voice is turned on; that is, the hot electric heating tube heats the cold water, which can immediately discharge water, which can prevent With thousands of boiling water, the user does not need to wait. Two solenoid valves are used to control the cold and hot water outlets; the temperature sensor monitors the water temperature and automatically cuts off the power if the temperature is abnormal; the liquid level sensor detects whether the water level is sufficient, and automatically if the water level is insufficient Alarm; the obstacle detection module detects whether a water cup is placed at the water outlet. If the water cup is detected and the water level meets the requirements, the light will be turned on, the heating tube will be heated, and hot water will be released.
The functional requirements of this water dispenser are instant heat, health, safety, energy saving, and voice prompts. According to the design function, using the modular design method, using 51 single-chip microcomputer to control, realize the intelligence of the drinking fountain.
3. Hardware design of water dispenser
The drinking fountain control system is mainly designed with single chip microcomputer as the core, including CPU, infrared pyroelectric sensor, liquid level sensor, solenoid valve, photosensitive sensor, voice module, temperature sensor and other parts.
1) Human body detection, power on. An infrared pyroelectric sensor is installed on the water dispenser as a human body detection module. When a person approaches the water dispenser, the human body detection module sends a signal to the single-chip microcomputer, and the single-chip microcomputer turns on the power supply. The photosensitive sensor module detects whether it is daytime. If it is daytime, the water dispenser voice module sends out a welcome voice and the working power indicator light is on. If it is night, the voice module will not start, only the working power indicator will be on. The voice module is activated during the day and closed at night, and can be adjusted to a family mode and a business model. The business model can be used in schools, supermarkets, hotels and other public places.
2) Water level detection, start lighting. After the working power is turned on, the liquid level sensor detects whether the water level is sufficient. If the water level is insufficient, the voice module will give an alarm and the water level alarm light will be on, prompting the user to add water and do not proceed to the next step. If the water level meets the requirements, the light at the outlet will turn on, and the heating process will enter.
3) Water cup detection, start heating. When the user presses the hot water button, the obstacle detection module formed by the photosensitive sensor detects whether the water cup is placed in the hot water outlet. If the water cup is detected, the hot water solenoid valve is opened, and the heater is heated immediately to release hot water. If the water cup is not detected, the hot water solenoid valve is closed, the hot water port does not flow out, and the user is prompted to put the water cup into the water outlet. The temperature sensor detects the instant electric heater in real time to ensure that the temperature is normal. If the temperature is abnormal, it will automatically cut off the power supply to prevent safety accidents. After the user receives the hot water, the water cup is removed, the single-chip microcomputer controls the instant heater and the lighting lamp to turn off. After the person leaves, the human body detection module sends a signal to the single-chip microcomputer to turn off the working power supply to achieve the purpose of energy saving.
4) Child lock. The water dispenser uses a hot water button and an obstacle detection module to dually control the hot water outflow. This design prevents children from putting their hands on the water outlet when playing, but because the hot water button is not pressed at the same time, the water outlet will not release hot water. To prevent children from being scalded by boiling water, the child lock function is effectively realized. At the same time, it also prevents the user from accidentally pressing the hot water button, but since there is no water cup to receive water, the water outlet will not release hot water.
Four, water dispenser software design
The software design of the system adopts a modular structure. According to the control function of the system, the design is carried out from top to bottom. The software structure of the whole system is simplified, which is convenient for design and debugging.
The water dispenser improves on the existing problems of the traditional water dispenser, and uses 51 single-chip microcomputers to control the water dispenser, which makes up for the shortcomings of the traditional water dispenser. Compared with traditional drinking fountains, it is healthier, safer, more energy-saving, and convenient. The intelligence of drinking fountains is reflected in the combination of single-chip microcomputer and various sensor modules. This comprehensive application concept is also the development trend of intelligent home appliances.