1. Hot water system description:
1) The heat pump unit is instructed to receive the water control electrical box after installation. There are three water level sensors in the water tank to monitor the water tank full water level, water level and emergency low water level. The water tank is also equipped with a temperature Sensor and the signal is reported to the water control electric box.
2) The heat pump unit has 3 water ports; there are multiple automatic valves to manage the water flow.
â— Cold water inlet: Connect the tap water main pipe and require pressure of 1.5 kg or more.
â— Hot water outlet: When the water tank is imported, the temperature of the produced hot water will reach the rated temperature regardless of the temperature and temperature change.
◠Return water inlet: When the water tank is connected to the water tank, when the water tank is not used for a long time, or a large amount of water is returned from the pipe network, the water temperature will drop. The built-in water pump of the heat pump unit will pump back the water, and then heat it back to the water tank to keep it. The water temperature is stable and the water is comfortable. The return water temperature control point can be set between 48 °C and 50 °C (hidden function). At this time, the return water heating does not need electric heating. This is the company's unique high-temperature water return technology.
3) There are 3 water level sensors in the water tank, which are suspended by heavy hammer. It is easy to change the water level or replace the fault sensor.
2. Control and operation:
The goal pursued by the system is stable water temperature and sufficient water volume, and another pursuit is high reliability. The control of the unit is two levels, the water path controller is the core of the upper layer control, and the core of the lower layer control is the built-in controller of the heat pump unit. They all use the preferred single-chip microcomputer as the microprocessor, and are equipped with powerful control developed by the company. The program forms a perfect intelligent control system.
1) System waterway control
There are three water level sensors in the water tank. When the hot water is continuously discharged and the water level drops from the full water level to the water supply level, the water circuit controller commands the heat pump to work, and the unit starts at intervals of 3 seconds to avoid a large starting current impact on the building power grid. . As the hot water is injected into the water tank, the water level rises to the full water level to touch the water level sensor, and the water circuit controller instructs the heat pump to stop working and enters the standby state.
The temperature sensor provided in the water tank detects the water storage temperature of the water tank. When the water storage temperature is lower than the set value, the water control circuit controls the group to start the circulating water pump, and draws back the water storage tank to heat it to restore the target temperature, and the unit enters itself. standby mode.
Because the waterway control idea is based on the water level and water temperature of the water tank, when a heat pump fails to work, the result is that other heat pumps automatically extend the running time and replenish the output without affecting the hot water supply service of the entire unit. Reflecting the unit system's ability to resist risks, that is, high reliability.
2) Heat pump unit control
The built-in controller of the heat pump unit, which contains a powerful microprocessor, is very complicated.
â— Detection; inlet pressure, water temperature, ambient temperature, temperature of the heat pump system, pressure, etc.
â— Control; compressor, fan motor speed, electronic expansion valve opening degree, each solenoid valve is switched.
â— Protection; the microprocessor calculates the detection signals, analyzes whether the operation status is abnormal, and determines what kind of failure occurs.
The heat pump unit is instructed to enter the protection stop, and the fault is reported in the form of code to prevent the unit from running the disease and causing permanent damage. For example, if the refrigerant leaks, it will stop and avoid damage to the compressor. The code can immediately find out the fault location and type, making the repair accurate and fast.
3) Compressor life problem
The compressor is the heart of the whole machine. Its operating life is inversely proportional to the square of the exhaust temperature. Reducing the exhaust temperature effectively extends the operating life of the compressor. The outlet temperature of the heat pump unit is related to the exhaust temperature. The worst conditions occur in high temperatures and high water temperatures, low temperatures and low water temperatures in winter and summer.
The compressor manufacturer stipulates that the maximum exhaust temperature is between 120 °C and 130 °C. After repeated hard work, our company has realized variable refrigerant flow control, variable water volume control and variable air volume control. Therefore, the direct heat air source heat pump unit is guaranteed to be high. Under the premise of energy efficiency, the exhaust temperature of the compressor is effectively controlled at 75 ° C ~ 95 ° C, to ensure the long life of the compressor.
4) Remote controller (optional)
The remote controller with liquid crystal display is a small box of 86 mm square, which is connected to the waterway controller by double wires. The line length is up to 100 meters. Each unit is equipped with one, and up to 16 heat pumps can be controlled for remote control. Convenient for dormitory engineering personnel management, do not need to go to the roof monitoring unit, you can observe under the dormitory.
The line controller has the following functions;
â— The unit number is displayed; after power-on, the heat pump number is displayed in 16 boxes, and the space indicates that there is no heat pump.
â— 3-stage timer; the time period of operation of the heat pump unit can be set within 24 hours. If the local power supply peaks and valleys, the heat pump unit can be set according to the local power supply peak and valley time period, and the electricity cost will be greatly saved.
â— Water tank storage status display; icon to instantly display the water tank water level high, medium and low 3 states, digital display instant water temperature, and can display 4 different tank fault codes
â— Heat pump unit status display; scrolling or turning pages show that each heat pump unit is running or standby, and the machine's water temperature.
â— Fault report; there are 20 different fault codes corresponding to different faults. When the heat pump unit is faulty, the heat pump unit serial number and its fault code are displayed at the same time, and can be immediately detected.
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