Pressure compensated flow rate controller with BTU meter

A constant-flow control valve and BTU meter assembly coupleable to a fluid-based heating or cooling system with a heating or cooling device, fluid supply and return lines connected to the heating or cooling device, and temperature sensors connected to the fluid supply and return lines and configured to measure fluid temperatures of supply fluid and return fluid relative to the heating or cooling device, wherein a temperature difference between the first and second temperatures is a temperature change across the heating or cooling device, the constant-flow control valve and BTU meter assembly comprising:

• a pressure independent, constant-flow control valve assembly connectable to the fluid-based heating or cooling system, the pressure independent, constant-flow control valve assembly having a valve body with an inlet and an outlet, a valve chamber with a fluid path therein extending between the inlet and outlet, an adjustable valve member in the valve chamber and disposed in at least a portion of the fluid path to define a throttle in the fluid path, a valve stem connected to the valve member and being rotatable as a unit relative to the valve body to change the position of valve member to change a fluid flow rate through the valve body, wherein the position of the valve member relative to the fluid path is directly related to the fluid flow rate through the fluid path, the valve stem having a free end portion projecting from the valve body;
• a first fluid pressure sensor positioned to measure the fluid pressure of fluid entering the inlet of the valve body;
• a second fluid pressure sensor positioned to measure the fluid pressure of fluid exiting the outlet of the valve body, wherein a difference between the first and second pressures is the pressure drop across the valve assembly;
• and
• a BTU meter assembly connected to the free end portion of the valve stem, wherein the valve stem is rotatable relative to at least a portion of the BTU meter assembly, the BTU meter assembly having a BTU body, and a position sensor coupled to the BTU body and to the valve stem, the position sensor being configured to detect a rotational position of the valve stem relative to the BTU body, the BTU meter assembly having a controller coupleable to the position sensor, to the first and second pressure sensors, and to the first and second temperature sensors, the controller being configured to determine the fluid flow rate based upon the pressure drop across the valve assembly and the rotational position of the valve stem, and the controller being configured to determine energy usage of the heating or cooling device based upon the flow rate and the temperature change across the heating or cooling device.

A method of determining energy consumption of a fluid-based heating or cooling system with a heating or cooling device and fluid flowing therethrough, method comprises:

• determining a first temperature of fluid flowing in a supply line to the heating or cooling device;
• determining a second temperature of fluid flowing in a return line from the heating or cooling device;
• determining a first fluid pressure of fluid entering an inlet of a pressure independent, constant-flow control valve assembly that controls a flow rate of the fluid in the fluid-based heating or cooling system, the control valve assembly comprising a valve body connected to the inlet and an outlet, a valve chamber in the valve body, and an adjustable valve member in the valve chamber and disposed in fluid path extending through the valve body between the inlet and outlet, the control valve assembly having a valve stem connected to the valve member, the valve stem being rotatable relative to the valve body to adjust the valve member and to adjust a fluid flow rate through the fluid path, the position of the valve member relative to the fluid path being directly related to the fluid flow rate through the fluid path, the valve stem being connected to a BTU meter and being rotatable relative to the BTU body and the valve body;
• determining a position of the valve stem relative to the valve body or the BTU body;
• determining a second fluid pressure of fluid exiting the outlet of the control valve assembly, wherein a difference between the first and second fluid pressures corresponds to a pressure drop across the valve;
• determining the flow rate of fluid passing through the control valve assembly based on the pressure drop across the valve and the position of the valve stem relative to the valve body or the BTU body;
• and
• determining energy consumption of the heating or cooling device in real time based upon the determined flow rate and the temperature change across the heating or cooling device.

A method of determining energy consumption of a fluid-based heating or cooling system with a heating or cooling device and fluid flow therethrough, method comprises:

• determining with a first temperature sensor a first temperature of fluid in a fluid supply line connected to the heating or cooling device, the supply line carrying the fluid to the heating or cooling device at the first temperature;
• determining with a second temperature sensor a second temperature of fluid in a fluid return line connected to the heating or cooling device, the supply line carrying the fluid away from the heating or cooling device at the second temperature;
• determining with a first fluid pressure sensor a first fluid pressure of fluid entering an inlet of a pressure independent, constant-flow control valve assembly that controls a flow rate of the fluid in the fluid-based heating or cooling system, the control valve assembly comprising a valve body connected to the inlet and an outlet, a valve chamber in the valve body, and an adjustable valve member in the valve chamber and disposed in fluid path extending through the valve body between the inlet and an outlet, control valve assembly having a valve stem connected to the valve member, the valve stem being rotatable relative to the valve body to adjust the valve member and to adjust a fluid flow rate through the fluid path, the position of the valve member relative to the fluid path being directly related to the fluid flow rate through the fluid path, the valve stem being movably connected to a BTU meter;
• determining with a position sensor a rotational position of the valve stem relative to the valve body or BTU body;
• determining with a second fluid pressure sensor a second fluid pressure of fluid exiting the outlet of the control valve assembly, wherein a difference between the first and second fluid pressures corresponds to a pressure drop across the valve;
• determining the flow rate of fluid passing through the control valve assembly based on the pressure drop across the valve and the rotational position of the valve stem relative to the valve body or BTU body;
• and
• determining energy consumption of the heating/cooling device in real time based upon the determined flow rate and the temperature change across the heating/cooling device.