【Daily Discussion】Utilities - HVAC - 20200715

In a mechanical circulating hot water heating system, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to ensure that the head generated by the water pump is in the same direction as the head caused by gravity; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system.

In mechanical circulating hot water heating systems, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to consider that the water pump head should be in the same direction as the gravitational head; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system. Consider the following factors: (1) Different cyclic dynamics. 　　(2) The connection points of the expansion tank are different. The mechanical circulation expansion tank is not connected to the main water supply pipe, but rather to the side of the water pump inlet on the return main pipe. Since the water in the expansion tank and expansion tube does not participate in the circulation, the water pressure at the connection between the expansion tube and the return pipe remains constant, regardless of whether the water pump is operating or not. This connection point is also known as the constant pressure point. Since the installation height of the expansion tank is higher than that of any point in the system, this connection ensures that the pressure at any point within the system remains above atmospheric pressure, whether the system is operating or stopped. This prevents negative pressure from occurring within the system, thus avoiding phenomena such as the vaporization of hot water or the intake of air. It can be seen that in mechanical circulation hot water heating systems, the expansion tank not only serves to accommodate the additional volume resulting from the expansion of water when it is heated, but also plays a role in maintaining constant pressure, ensuring that no negative pressure occurs at any point within the system. 　　(3) The exhaust methods and exhaust devices are different. 　　

In a mechanical circulating hot water heating system, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to consider that the water pump head should be in the same direction as the gravitational head; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system.

In mechanical circulating hot water heating systems, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to consider that the water pump head should be in the same direction as the gravitational head; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system.

In mechanical circulating hot water heating systems, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to consider that the water pump head should be in the same direction as the gravitational head; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system.

In mechanical circulating hot water heating systems, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to consider that the water pump head should be in the same direction as the gravitational head; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system.

In a mechanical circulation hot water heating system, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to consider that the water pump head should be in the same direction as the gravitational head; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system. ? ???Consider the following factors: ? ???(1) The cyclic dynamics are different. 　　(2) The connection points of the expansion tank are different. The mechanical circulation expansion tank is not connected to the main water supply pipe, but rather to the side of the water pump inlet on the return main pipe. Since the water in the expansion tank and expansion tube does not participate in the circulation, the water pressure at the connection between the expansion tube and the return pipe remains constant, regardless of whether the water pump is operating or not. This connection point is also known as the constant pressure point. Since the installation height of the expansion tank is higher than that of any point in the system, this connection ensures that the pressure at any point within the system remains above atmospheric pressure, whether the system is operating or stopped. This prevents negative pressure from occurring within the system, thus avoiding phenomena such as the vaporization of hot water or the intake of air. It can be seen that in mechanical circulation hot water heating systems, the expansion tank not only serves to accommodate the additional volume resulting from the expansion of water when it is heated, but also plays a role in maintaining constant pressure, ensuring that no negative pressure occurs at any point within the system. 　　(3) The exhaust methods and exhaust devices are different. 　　

In mechanical circulating hot water heating systems, the circulation pressure of the water pump is the main factor to consider. However, it should be taken into account at the time of design that the head generated by the water pump is in the same direction as the gravitational head; this generally leads to a good heating effect. If the pressure is unstable, it can cause damage to the heating system. A mechanical circulation hot water heating system is one in which a circulation pump is installed; the mechanical energy of this pump is used to force the water to circulate within the system. In the mechanical circulation system pit, a circulation water pump has been installed, which increases the regular operating costs and maintenance workload of the system ； However, due to the high pressure generated by the water pump, the heating area can be expanded. Mechanical circulating hot water heating systems can be used not only in single buildings but also in multiple buildings, and can even evolve into regional hot water heating systems. Mechanical circulating hot water heating systems have become the most widely used type of heating system. 　　(1) The cyclic power is different. The mechanical circulation is driven by a water pump, which forces the water to flow. Circulation water pumps are generally installed on the return main pipe in front of the boiler inlet. In this way, the water pump can operate reliably under return-water conditions with a lower system water temperature. 　　(2) The connection points of the expansion tank are different. The mechanical circulation expansion tank is not connected to the main water supply pipe, but rather to the side of the water pump inlet on the return main pipe. Since the water in the expansion tank and expansion tube does not participate in the circulation, the water pressure at the connection between the expansion tube and the return pipe remains constant, regardless of whether the water pump is operating or not. This connection point is also known as the constant pressure point. Since the installation height of the expansion tank is higher than that of any point in the system, this connection ensures that the pressure at any point within the system remains above atmospheric pressure, whether the system is operating or stopped. This prevents negative pressure from occurring within the system, thus avoiding phenomena such as the vaporization of hot water or the intake of air. It can be seen that in mechanical circulation hot water heating systems, the expansion tank not only serves to accommodate the additional volume resulting from the expansion of water when it is heated, but also plays a role in maintaining constant pressure, ensuring that no negative pressure occurs at any point within the system. 　　(3) The exhaust methods and exhaust devices are different. In natural circulation, air can generally be removed using an expansion tank. However, in mechanical circulation, since the connection point of the expansion tank is located on the return main pipe, it is not easy to use the expansion tank for air removal; instead, a dedicated exhaust device such as an air collection tank is required. The exhaust device is generally installed at the highest point of the system. To facilitate exhaust, the main water supply pipes generally have an upward slope in the direction of water flow (slope upward), with a slope value of 0.003. 　　Compared to natural circulation, since a water pump is used as the power source, a higher flow rate can be achieved; as a result, the pipe diameter is smaller while the range of action is larger. Additionally, the boiler does not need to be placed at a lower level than the radiators on the ground floor.

In mechanical circulating hot water heating systems, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to consider that the water pump head should be in the same direction as the gravitational head; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system.

In mechanical circulating hot water heating systems, the circulation pressure of the water pump is the main factor to consider. However, it is also necessary to consider that the water pump head should be in the same direction as the gravitational head; this generally leads to a better heating effect. If the pressure is unstable, it can cause damage to the heating system.