A three-dimensional analog simulation test system for gas-liquid countercurrent in an abandoned mine goaf includes a three-dimensional analog simulation device configured to simulate an analog environment of gas-liquid countercurrent in an abandoned mine goaf, a gas supply system, an automatic water pressure control system and a hydraulic loading system. The three-dimensional analog simulation device includes a reaction frame and a three-dimensional analog simulation chamber. The reaction frame includes a beam, a base and a column for connecting the beam and the base. The three-dimensional analog simulation chamber is arranged inside the reaction frame. The test system can be used to simulate the gas-liquid countercurrent in an abandoned mine goaf so as to study the evolution of water accumulation and gas enrichment in long-term abandonment of closed mines and the migration evolution rules of gas-liquid two-phase in abandoned mines with high gas density.

A three-dimensional analog simulation test system for gas-liquid countercurrent in an abandoned mine goaf includes a three-dimensional analog simulation device configured to simulate an analog environment of gas-liquid countercurrent in an abandoned mine goaf, a gas supply system, an automatic water pressure control system and a hydraulic loading system. The three-dimensional analog simulation device includes a reaction frame and a three-dimensional analog simulation chamber. The reaction frame includes a beam, a base and a column for connecting the beam and the base. The three-dimensional analog simulation chamber is arranged inside the reaction frame. The test system can be used to simulate the gas-liquid countercurrent in an abandoned mine goaf so as to study the evolution of water accumulation and gas enrichment in long-term abandonment of closed mines and the migration evolution rules of gas-liquid two-phase in abandoned mines with high gas density.

A three-dimensional analog simulation test system for gas-liquid countercurrent in an abandoned mine goaf includes a three-dimensional analog simulation device configured to simulate an analog environment of gas-liquid countercurrent in an abandoned mine goaf, a gas supply system, an automatic water pressure control system and a hydraulic loading system. The three-dimensional analog simulation device includes a reaction frame and a three-dimensional analog simulation chamber. The reaction frame includes a beam, a base and a column for connecting the beam and the base. The three-dimensional analog simulation chamber is arranged inside the reaction frame. The test system can be used to simulate the gas-liquid countercurrent in an abandoned mine goaf so as to study the evolution of water accumulation and gas enrichment in long-term abandonment of closed mines and the migration evolution rules of gas-liquid two-phase in abandoned mines with high gas density.

A method of controlling fluid flow in a fluid network system by fluid machines includes obtaining a respective current flow rate associated with each fluid machine, obtaining a current fluid machine speed of each fluid machine, obtaining desired flow rates in the system, and determining a new fluid machine speed for each fluid machine based on the current fluid machine speed and a change in the fluid machine speed required to obtain the desired flow rates. The change in fluid machine speed is determined by minimizing a total fluid machine power which is a function dependent of the change in the fluid machine speed, the minimization being performed with constraints for flow rate, fluid machine pressure and fluid machine speed. The method include controlling the speed of the fluid machines according to the new fluid machine speeds such that the minimum total fluid machine power in the system is attained.

A method of controlling fluid flow in a fluid network system by fluid machines includes obtaining a respective current flow rate associated with each fluid machine, obtaining a current fluid machine speed of each fluid machine, obtaining desired flow rates in the system, and determining a new fluid machine speed for each fluid machine based on the current fluid machine speed and a change in the fluid machine speed required to obtain the desired flow rates. The change in fluid machine speed is determined by minimizing a total fluid machine power which is a function dependent of the change in the fluid machine speed, the minimization being performed with constraints for flow rate, fluid machine pressure and fluid machine speed. The method include controlling the speed of the fluid machines according to the new fluid machine speeds such that the minimum total fluid machine power in the system is attained.