Fuel flow divider and ecology system for a gas turbine engine fuel flow control system

A flow divider and ecology system for a gas turbine engine that includes a start nozzle manifold and a run nozzle manifold, the system comprising:

• a flow divider valve body including an inlet port, a start nozzle manifold outlet port, a run nozzle manifold outlet port, a start flow orifice disposed between the inlet port and the start nozzle manifold outlet port, and an inner surface that defines a flow divider valve chamber;
• a flow divider valve element disposed within the flow divider valve chamber and movable therein between a closed position and a plurality of open positions, the flow divider valve element including an inner surface, an outer surface, and a flow regulation port, the inner surface defining an internal channel, the flow regulation port extending through the flow divider valve element between the inner surface and the outer surface and providing continuous fluid communication between the internal channel and the run nozzle manifold outlet port when the flow divider valve element is in the plurality of open positions;
• an ecology valve body including a control pressure port, a burn flow pressure port, a run nozzle port, and an inner surface that defines an ecology valve chamber, the burn flow pressure port in fluid communication with the internal channel of the flow divider valve element, the run nozzle pressure port in fluid communication with the run nozzle manifold outlet port;
• and
• an ecology valve element disposed within the ecology valve chamber and movable therein between a plurality of positions, the ecology valve element dividing the ecology valve chamber into a variable volume control chamber and a variable volume fuel reservoir, the variable volume control chamber in fluid communication with the control pressure port, the ecology valve element configured, in response to fuel pressure at the control pressure port, to selectively place the variable volume fuel reservoir in fluid communication with one of the burn flow pressure port and the run nozzle pressure port;
• wherein the flow divider valve element is configured such that:
• when the flow divider valve element is in the closed position, the inlet port is fluidly isolated from the start nozzle manifold outlet port, the run nozzle manifold outlet port, and the internal channel, and
• when fuel pressure at the inlet port is between a first predetermined pressure and a second predetermined pressure:
• the flow divider valve element is in one or more of the open positions and the inlet port is in fluid communication with (i) the start nozzle manifold outlet port via the start flow orifice and (ii) the run nozzle manifold outlet port via the internal flow channel and the flow regulation port, and
• fuel flow through the start flow nozzle manifold outlet port is substantially constant regardless of fuel flow into the inlet port;
• and
• wherein:
• the flow divider valve body and flow divider valve element are configured to define, within the valve chamber, an inlet chamber, a run nozzle manifold chamber, via the start flow orifice, regardless of flow divider valve element position,
• the run nozzle manifold chamber is in fluid communication with the inlet chamber, via the internal flow channel and the flow regulation port, when the flow divider valve element is in the plurality of open positions, and
• the start nozzle manifold chamber and the run nozzle manifold chamber and are in fluid communication with each other when fuel pressure at the inlet port exceeds the second predetermined pressure.