1. Local climate and mine inlet temperature
According to historical weather data, from June to August 2015-2019, the highest temperature records in this area are 32℃, 31℃, 36℃, 31℃, 31℃. The mine is located in an industrial park, and the air flow is side-in and top-out.
If the maximum temperature of the environment in summer is calculated at 34°C, according to the characteristics of the heat source of the mine, the maximum temperature of the factory’s summer inlet air should not exceed 37°C,
passing through the water curtain After the air temperature should not exceed 31 ℃, the relative humidity should be between 30-80%.
2. Introduction to the mining machine
The S19 Pro mining machine is a chassis power integrated design. Its bare metal size is 370×195.5×290mm. It can be placed horizontally or vertically according to the height of the mine shelf; the mass is 13.2kg.
The heat dissipation of the mining machine is designed with front and rear double-tube fans, and the outer surface of the fan is equipped with a mesh cover, which ensures that the mine operation and maintenance personnel avoid accidentally touching the blades and cause injuries, which protects the safety of the operation and maintenance personnel; the back of the fan is covered with a grille, which effectively prevents Foreign particles enter the high-speed rotating fan and hit the hashrate board.
The voltage of a single fan is 12V, the current is 1.65A, the maximum speed is 6150rpm, and the maximum air volume is 197cfm. According to the changes in the series and parallel characteristics of the fans, the single-sided parallel fan design of the miner significantly increases the ventilation; the series design of the fans on both sides of the miner significantly increases the resistance of the miner to environmental resistance, that is, the ventilation of the miner will not follow the mine. The changes in the field environment fluctuate sharply.
The internal computing power board of the mining machine uses a whole heat sink for heat dissipation. The heat sink is of a streamlined design. Although the wind resistance cannot be effectively reduced, the heat sink design effectively increases the heat diffusion area of the chip, making the chip The generated heat can be evenly and quickly transferred to the heat sink, and be taken away by the wind in time.
3. Measured data of mining machine operation
On-site personnel select a mining machine under a certain position of the shelf for testing, and obtain the following data through the monitoring background.
The air inlet temperature of the S19 Pro miner is 23.1℃, the relative humidity is 70%, and the air outlet temperature is 38.8℃; the relative humidity is 32%, the average air volume is 370cfm; the power outlet air temperature is 28.0℃. The power consumption of the S19pro mining machine is 3320W, and the mining machine control page shows an average computing power of 111.8TH/s, so the power consumption ratio of the S19 mining machine is 29.69W/T.
The effective computing power of S19 Pro on the mining pool side is also amazing. The background of ViaBTC shows that the effective computing power averages about 111 Th/s. After accessing the "firepower machine gun pool" and turning on the "hourly redemption" function, the profit is the highest Compared with the traditional PPS+ model, the increase can reach 23.99%. The figure below shows the calculation of the income obtained by different accounts through ViaBTC.
The influence of changes in air volume and air temperature on the operation of mining machines
According to relevant statistics, 45% of electronic products are damaged due to high temperature. The high temperature problem that occurs in the mine is mainly due to insufficient ventilation, which causes the temperature of the air outlet of the mining machine to increase. In order to obtain the operating status of the mining machine in different ventilation environments, the on-site personnel observe the change of the mining machine's computing power by changing the air flow through the mining machine. The results obtained are as follows.
The air flow environment of the mining machines at different locations in the mine is quite different, and the air volume obtained by the mining machines is quite different, which directly affects the temperature of the air outlet of the mining machine. In order to ensure that the temperature of the air outlet of the mining machine is maintained within the appropriate range, the mine should calculate the air flow field of each machine position during the design process, and design a water curtain or other equipment to reduce the summer air inlet temperature of the mining machine. During operation, the distance between the mining machine and the water curtain should be greater than 2 meters to avoid water splashing into the mining machine; the workshop should be kept clean, and the number of particles with a diameter of not less than 0.5μm in the workshop environment should be ≤32.5 million particles/m3.
For the mine site used in this mining machine evaluation experiment, the ventilation layout is reasonable and the inlet air temperature is low. It is calculated that the hot outflow of the mining machine in summer does not exceed 47°C, the operating environment for the heat dissipation of the mining machine is good, and the relative humidity and the concentration of dust particles are good. Keep it within an appropriate range.