Method and system for heat recovery from products of combustion and charge heating installation including the same

Patent metadata

Field	Value
Publication number	US-9618203-B2
Application number	US-201313955909-A
Country	US
Kind code	B2
Filing date	Jul 31, 2013
Priority date	Sep 26, 2012
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A plurality of independently flow rate-controlled flows of fuel may be preheated at a heat exchanger (or both oxidant and fuel at separate heat exchangers) by heat exchange with a hot shell-side (heat transfer) fluid. The separate flows of hot fuel are directed to associated separate burners where they combust with flows of fuel to produce hot combustion gases. The hot combustion gases are used to preheat the hot shell-side fluid at a recuperator or regenerator.

First claim

What is claimed is:

1. A charge heating installation utilizing pre-heated fuel, comprising:
a system for recovering heat from a furnace comprising:
a source of gaseous fuel;
a recuperator or regenerator, said recuperator or regenerator adapted and configured to exchange heat between a flow of cool shell-side fluid and a flow of hot combustion gases from a furnace to produce a flow of hot shell-side fluid;
a first shell and tube heat exchanger comprising:
a shell,
a hot shell-side fluid inlet and a cool shell-side fluid outlet formed in the shell thereof,
first and second fuel inlets receiving first and second main flows of the fuel, respectively,
first and second fuel inlet interior spaces receiving said first and second main flows of the fuel, respectively, said first and second fuel inlet interior spaces being disposed within said shell and being divided from one another by a divider,
first and second sets of one or more fuel tubes each, the first and second sets receiving the first and second main flows of fuel, respectively, from the first and second fuel inlets via said first and second fuel inlet interior spaces, respectively, each of the fuel tubes extending through an interior of the shell, an upstream tubesheet dividing said first and second fuel inlet interior spaces from the interior portion of said shell that each of the fuel tubes extends through,
first and second fuel outlet interior spaces receiving said first and second main flows of the fuel, respectively, from said first and second sets of one or more fuel tubes each, respectively, said first and second fuel inlet outlet spaces being disposed within said shell and being divided from one another by a divider,
first and second fuel outlets receiving the first and second main flows of fuel, respectively, from the first and second sets of fuel tubes, respectively, via said first and second fuel outlet interior spaces, respectively, a downstream tubesheet or a downstream imperfectly sealed tubesheet-like divider dividing said first and second fuel outlet interior spaces from the interior portion of the shell that each of the fuel tubes extends through, the first shell and tube heat exchanger being adapted and configured to transfer heat from the flow of hot shell-side fluid to the main flows of fuel flowing through the fuel tubes;

a first cool fuel feed conduit fluidly communicating between the source of fuel and the first fuel inlet;
a second cool fuel feed conduit fluidly communicating between the source of fuel and the second fuel inlet;
first and second fuel flow control devices disposed in the first and second cool fuel feed conduits, respectively;
a first controller adapted and configured to control flow rates of fuel from the fuel source and through the first and second cool fuel feed conduits with the first and second fuel flow control devices, respectively, wherein each of the first and second fuel flows through the cool fuel feed conduits may be controlled by said first controller independently and separately from control of one other; and
first and second hot fuel feed conduits receiving the first and second main fuel flows, respectively, from the first and second fuel outlets, respectively;

first and second burners receiving first and second flows of hot fuel, respectively, from the first and second hot fuel feed conduits, respectively; and
a melting furnace containing a charge, each of the burners being operatively associated with the furnace such that the charge is heated through combustion of an oxidant and the hot fuel injected by the burners, wherein the recuperator or regenerator receives a flow of hot combustion gases from the combustion of the hot fuel and the oxidant in the furnace to produce the flow of hot shell-side fluid.

2. The charge heating installation of claim 1 , wherein none of the first and second fuel flows bypass the heat exchanger so that the first and second fuel flows become the first and second main fuel flows, respectively.

3. The charge heating installation of claim 1 , further comprising first and second bypass valves disposed in the first and second cool fuel feed conduits, respectively, wherein:
each of the bypass valves is adapted and configured to split an associated one of the fuel flows into first and second portions;
the first portion split by the first bypass valve being the first main fuel flow and the second portion split by the first bypass valve being a first bypass fuel flow;
the first portion split by the second bypass valve being the second main fuel flow and the second portion split by the second bypass valve being a second bypass fuel flow;
the first and second bypass flows flowing through first and second bypass flow conduits disposed entirely outside the shell;
the first hot fuel feed conduit receiving the first bypass flow from the first bypass flow conduit at which the first bypass flow is combined with the first main fuel flow; and
the second hot fuel feed conduit receiving the second bypass flow from the second bypass flow conduit at which the second bypass flow is combined with the second main fuel flow.

4. The charge heating installation of claim 1 , wherein each of the splits of the first and second fuel flows into the respective first and second portions is controlled by the controller separately and independently of one another.

5. The installation of claim 1 , wherein none of the first and second fuel flows bypass the heat exchanger so that the first and second fuel flows become the first and second main fuel flows, respectively.

6. The installation of claim 1 , further comprising first and second bypass valves disposed in the first and second cool fuel feed conduits, respectively, wherein:
each of the bypass valves is adapted and configured to split an associated one of the fuel flows into first and second portions;
the first portion split by the first bypass valve being the first main fuel flow and the second portion split by the first bypass valve being a first bypass fuel flow;
the first portion split by the second bypass valve being the second main fuel flow and the second portion split by the second bypass valve being a second bypass fuel flow;
the first and second bypass flows flowing through first and second bypass flow conduits disposed entirely outside the shell;
the first hot fuel feed conduit receiving the first bypass flow from the first bypass flow conduit at which the first bypass flow is combined with the first main fuel flow; and
the second hot fuel feed conduit receiving the second bypass flow from the second bypass flow conduit at which the second bypass flow is combined with the second main fuel flow.

7. The installation of claim 6 , wherein each of the splits of the first and second fuel flows into the respective first and second portions is controlled by the controller separately and independently of one another.

8. A method for recovering heat from a melting furnace containing a charge, comprising the steps of:
providing the charge heating installation of claim 1 ;
injecting oxidant and a first flow of hot fuel from the first burner;
injecting oxidant and a second flow of hot fuel from the second burner;
combusting the injected oxidant and hot fuel to heat a charge in the furnace and produce hot combustion gases;
exchanging heat with the recuperator or regenerator between a flow of cool shell-side fluid and a flow of the hot combustion gases to produce a flow of hot shell-side fluid;
independently and separately controlling flow rates of first and second flows of fuel flowing in first and second cool fuel feed conduits upstream of the first and second fuel inlets;
feeding the independently and separately flow rate-controlled first and second flows of fuel to

Assignees

• L'Air Liquide Société Anonyme Pour L'Étude Et L'Exploitation Des Procédés Georges Claude
• Air Liquide American
• L'Air Liquide Société Anonyme Pour L'Étude Et L'Eploitation Des Procedes Georges Claude

Inventors

• Kang Taekyu
• Mcandrew James J F
• Joumani Youssef
• Tsiava Remi Pierre

Classifications

• F23L7/007

  Supplying oxygen or oxygen-enriched air · CPC title

• F23L15/02 Primary

  Arrangements of regenerators · CPC title

• F23L15/00

  Heating of air supplied for combustion · CPC title

• F23L15/04 Primary

  Arrangements of recuperators · CPC title

• F23D14/66

  Preheating the combustion air or gas · CPC title