Thread Content
The temperature control valve features PI and PID control functions, offering precise control. It supports multi-loop control and has a variety of functions, enabling the control of fluid flow rate, pressure, pressure difference, temperature, humidity, enthalpy, and air quality. The actuators are available in electromechanical and electro-hydraulic types, featuring manual and automatic control functions. They offer precise control, high shut-off force, and adjustable flow characteristics (linear, proportional, etc.). The electro-hydraulic actuator features automatic reset protection in the event of power loss; it can receive signals of 0-10V or 4-20MA, and includes a valve position feedback function. The thermostatic valve heating system is designed and calculated based on the maximum heat load required at the lowest recorded outdoor temperature. However, the design temperature of a thermostatic valve is only relevant for a few days during the extremely cold season, which means that the heating system operates at full capacity only for those few days throughout the heating season. Generally speaking, the heat load required to maintain room temperature is much lower than the designed value, and moreover, this heat load is constantly changing. The heat load varies daily throughout the heating season as well. A thermostatic valve can automatically maintain an accurate room temperature as per preset requirements, unaffected by weather conditions. Install a temperature control valve in each room to ensure that the \"free\" heat generated by sunlight, lighting systems, machinery, and human bodies can be fully utilized, thereby achieving energy savings. Solving the hydraulic balance problem in heating systems Thermostatic valves are an essential component in double-pipe systems in high-rise buildings, as they help to resolve the hydraulic balance issues within the piping network. Composition of electric temperature control valves: It consists of an electric control valve, a temperature controller, and a temperature sensor combined together. Electric three-way control valves are classified into merge valves and split valves based on the way the fluid is directed. The merging valve has two inlets, and the mixture flows out through one outlet. The diverter valve has a fluid inlet, from which the fluid is divided into two streams that flow out through two outlets. The structure of the parallel three-way control valve is similar to that of the series three-way control valve. Its features are as follows: 1. The electric three-way control valve has two valve spools and valve seats, and its structure is similar to that of a double-seat valve. However, in electric three-way control valves, when the flow area between one valve element and its seat increases, the flow area between the other valve element and its seat decreases. In a two-seat valve, the flow area between the two spools and the seats increases or decreases simultaneously. 2. The air-open and air-close functions of the electric three-way control valve can be achieved by selecting the direct-acting or reverse-acting type of actuator. Changing the air-open to air-close mode of a two-seat valve can be achieved by reversing the installation of the valve body or spool relative to the valve seat. 3. Electric three-way control valves are used in control systems where fluid mixing is required; since they replace one air-operated open control valve and one air-operated closed control valve, they help to reduce costs and minimize installation space. 4. Electric three-way control valves are also used in applications requiring bypass control; for example, one stream of fluid passes through a heat exchanger for heat exchange, while another stream does not undergo such exchange. When the electric three-way control valve is located in front of the heat exchanger, a diverging three-way control valve is used; when the three-way control valve is installed behind the heat exchanger, a converging electric three-way control valve is used. Since the fluid flowing through the three-way valve installed before the heat exchanger has the same temperature, the leakage amount is low; whereas the fluid flowing through the three-way valve installed after the heat exchanger has different temperatures, resulting in different degrees of expansion of the valve core and seat, and thus the leakage amount is higher. Generally, the temperature difference between the two fluids should not exceed 150°C. A three-way control valve with a cage structure, equipped with balance holes and guided by a valve cage. Therefore, the **unbalanced force can be reduced. Early three-way control valves used thin-walled cylindrical openings, with the valve spool guided by its sides; although this reduced unbalanced forces, significant unbalanced forces still existed when one flow direction was approaching shut-off. Moreover, these unbalanced forces varied as the valve opening changed. A valve cage structure equipped with balance holes could eliminate such unbalanced forces and provide damping, which helped to ensure the stable operation of the control valve. Due to the high leakage rate of electric three-way control valves, in applications where low leakage is required, two control valves (along with two-way connectors) can be used to split or combine the fluid flow, or to regulate the proportion of the fluid.