Abstract:
Heat from a rotating prime mover(s) driving a fluid shear pump, heat from the prime mover and any exhaust heat generated by the prime mover is collected. The heat energy collected from all of these sources is transmitted through heat exchangers to a fluid where heat energy is desired. This fluid heating process is performed in the absence of an open flame.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to processes used to heat and pump industrial fluids, where the heating process does not require an open flame. 
       BACKGROUND OF THE INVENTION 
       [0002]    Industrial applications may require large volumes of heated fluid, primarily water, but not excluding other fluids such as hydrocarbons or caustic solutions. Although reference is made to all of these fluids, in order to identify fluids separately, these fluids will be identified as being water. 
         [0003]    Specific environments may require that no open flame be present. This most commonly occurs in the energy industry. The present invention was created to heat fluids in these types of environments. 
         [0004]    Oilfield fracture stimulation treatments require large volumes of water. Water is warmed to allow fluid to gel and carry sand into a reservoir to be stimulated. Common practise has been to transport water, usually by truck, to several tanks located at a site of a recently drilled well. This water is heated by open flamed trucks which utilize diesel or propane fired burners. These burners are very inefficient, utilizing excessive amounts of fuel. They are also extremely hazardous, and can lead to fires, severe burns, and even fatalities. 
         [0005]    The present invention allows an opportunity to eliminate the trucking of water, and move warm water via temporary pipelines, typically agricultural irrigation pipes, to fill the subject tanks. This water is heated as it is pumped into the pipelines, preventing freezing issues in cold weather. Once the tanks are filled, the heater of the present invention is moved to the tank site, and further heats the water, or any other fluid contained in the tanks, to the desired temperature. The heating process is efficient and safe, making the best use of fuel in a flameless environment. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention consists of a number of major components which are connected in such a way that the process provides efficient, flameless heat. The components are generally trailer mounted, but may also be truck or skid mounted. 
         [0007]    The largest component is the prime mover. The prime mover is most often a diesel engine, gasoline engine or natural gas engine. An electric drive may also be used depending on the environmental considerations. 
         [0008]    Connected directly to the drive shaft of the prime mover is a dynamic heater such as a fluid shear pump. This component utilizes the majority of the power available from the prime mover, and converts this energy into heat. The pump shears a heater fluid such as oil. This oil is contained in a separate system, and transfers its heat energy to the water through a liquid to liquid heat exchanger. 
         [0009]    Also connected to the drive of the prime mover is a main pump to move the water through the system. This pump is typically a centrifugal pump, usually self-priming to allow movement of water from a lower elevation (lake, pond, or river) into the heating unit, and out to the pipeline or tank. The pump also provides the flow of cooling water to allow the engine to operate properly, while heating the water at the same time. 
         [0010]    The remaining major components to the system are heat exchangers. 
         [0011]    A first heat exchanger is a liquid to liquid heat exchanger, mentioned above, that transfers heat from the heater fluid, generated by the fluid shear pump, to the water. 
         [0012]    A second heat exchanger is also a liquid to liquid heat exchanger, which transfers heat generated in the engine coolant to the water. This fluid is pumped by the main pump, as mentioned above. 
         [0013]    A third heat exchanger is an air to liquid heat exchanger which transfers heat generated in the turbocharger intercooler on a diesel prime mover engine to the water. 
         [0014]    A fourth heat exchanger is also an air to liquid heat exchanger, which transfers the heat generated in the engine exhaust of the prime mover to the water. 
         [0015]    Other system components include a fuel tank to operate the prime mover engine, a heater fluid reservoir, a trailer to house the components, and a control system to maintain operation of the system and alarm in the event of a mechanical failure. 
         [0016]    These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The following drawings illustrate examples of various components of the invention disclosed herein, and are for illustrative purposes only. Other embodiments that are substantially similar can use other components that have a different appearance. 
           [0018]    The FIGURE schematically illustrates the flow of heater fluid and the flow of water for exchange of heat from four sources of heat. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0019]    In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
         [0020]    Reference will now be made to the FIGURE for a more detailed description of the flameless heat generation process. Each component will be described in detail, followed by an overview of the heat generation process. 
         [0021]    The largest component of the flameless process is the prime mover  10 . The prime mover can be any type of engine, fueled by a variety of fuels such as diesel, propane or natural gas. It can also be an electrical engine in certain applications. 
         [0022]    The fuel driven engine is typically set up like a marine engine, which will have a water cooled intercooler  90  to cool and increase the density of the air travelling from a compressor side of a turbocharger of the engine  10  to an engine intake. The engine will also have water/engine coolant heat exchanger portions  60 ,  66  to keep the engine running within its ideal temperature range. Typical marine engines have a built in water pump to move water through the intercooler and the heat exchanger. The prototype model of the heat generation process utilized such a pump. This pump was able to be removed for the second generation units and the discharge of the main water pump  40  was utilized for this purpose. 
         [0023]    Attached to the prime mover  10  is a dynamic heater, such as a fluid shear pump  20 . The majority of the engine horsepower is used to shear a heating fluid in the fluid shear pump  20 . The heating fluid can be any fluid that is practical to be used in an oilfield environment. The fluid should be environmentally friendly as well as non-combustible and be commonly used in oilfield applications. Examples of heating fluids used in this application include oil and glycol. 
         [0024]    The fluid shear pump  20  can use either metal plates moving across each other, spinning discs or pumping fluids through orifices to create fluid shear forces large enough to generate heat in the heating fluid. The majority of the power generated by the engine is used for the purpose of shearing fluid to generate heat. The fluid shear pump  20  is bolted directly to the engine  10  and is powered by the output shaft  12  of the engine. 
         [0025]    Between the engine  10  and fluid shear pump  20  is a torsional vibration dampener (not shown), which is used to smooth out the vibrations created by the prime mover. The use of a torsional vibration dampener extends the life of the output shaft  12  and the fluid shear pump  20 . 
         [0026]    Bolted directly to the fluid shear pump  20  is heater fluid pump  30 , which is either a hydraulic oil pump or a glycol pump. This pump  30  is typically driven by the prime mover through the fluid shear pump shaft  20 . The purpose of this pump is to move the heating fluid through the various components. 
         [0027]    Water pump  40  is a self-priming centrifugal trash pump capable of pumping fluids to and from various elevations. Pump  40  is driven by shaft  18  off of drive shaft  12 . It must be capable of pumping fluids containing contaminants such as sand, silt, gravel, and fine material found in rivers and creeks. It must also be drainable for winter service. 
         [0028]    Exhaust heat exchanger  50  must be constructed of stainless steel or similar non-corrosive material. The prime mover exhaust  14  enters the bottom  16  of the heat exchanger  50  where the exhaust is directed upward to heat tube bundles containing water within heat exchanger  50 . Typically the exhaust gases enter the exhaust heat exchanger at temperatures of up to 700° F. (400° C.) and exit from pipe  54  at 70° F. (25° C.). 
         [0029]    Engine coolant is pumped by a pump portion of engine coolant/water heat exchanger portions  60 ,  66  to circulate engine coolant through pipes  68  and  69 . Water is pumped through water heat exchanger portion  60  to draw off heat from circulating coolant passing through pipes  68  and  69 . This keeps the engine coolant within the operating range of the engine. This heat exchanger is built of marine grade material. 
         [0030]    Heater fluid/water heat exchanger  70  is a heat exchanger that is used to transfer heat from the heated fluid of shear pump  20  to the water. It is also specified to be of marine grade material. 
         [0031]    Heater fluid reservoir  80  is a reservoir tank that is used to hold the heating fluid. It is typically 50 gallons (200 litres) in size and has an attached filter for filtering the heating fluid. 
         [0032]    Water inlet  100  and water outlet  110  are used to transfer the water into and out of the trash pump  40 . They either have cam lock or hammer unions to attach to flexible hoses. 
       The Heating Process 
       [0033]    The heating process consists of collecting the heat from four different components and transferring it to the water. The four heat source components are the fluid heater pump  20 , engine coolant/water heat exchanger portions  60 ,  66 , the engine water/air intercooler  90  and the exhaust heat exchanger  50 . 
         [0034]    The heating process begins by starting the prime mover  10 . At this time the pump  40  will start pumping and begin to fill with water. Air will be purged from the system using a series of bleeder valves. 
         [0035]    The water enters the system through the inlet pipe  100 . Water enters the trash pump  40 , which is used to pump water to the various components as well as to the outlet pipe  110 . From the outlet pipe  110 , water is pumped along pipeline  42  to water/air intercooler  90 , and then on to the engine coolant heat exchanger portion  60  by pipeline  62 , through the exhaust heat exchanger  50  by pipeline  64  and then back to the water inlet pipe  100  by pipeline  52 . 
         [0036]    In the prototype model, an impeller type pump attached directly to and run by the prime mover was used for this function. The second generation machine utilized the outlet (high pressure) side (outlet  110 ) of the centrifugal pump  40  to do this function more simply and efficiently by eliminating a high maintenance pump. The centrifugal pump  40  is also used to pump water from the high pressure side (outlet  110 ) of the pump  40  by pipeline  112  to pump water to heater fluid/water heat exchanger  70  and then back to the inlet side of the pump by pipeline  102 . 
         [0037]    Once the prime mover  10  has warmed up and the air has been purged from the system, the prime mover  10  is throttled up to maximum power and rpm. At this time the fluid heat pump  20  begins to generate heat. This heat is transferred to the heater fluid, which is pumped from the reservoir  80 , through the heater fluid pump  30  by pipeline  82 , through the fluid heat pump  20  by pipeline  22  to pick up the heat generated by pump  20 , and through the heat exchanger  70  by pipeline  72 . It is at the heat exchanger  70  that heat is transferred from the heater fluid to the water which is returned to the inlet by pipeline  102 . 
         [0038]    Once the fluid has passed through the heat exchanger  70  and the heat has been removed from the heater fluid, the heater fluid is returned to the heater fluid reservoir  80  by the pipeline  74 , where it is stored and filtered until it is pumped back through this cycle. The heater fluid is in a closed system that continually follows this route. This is a first source of heat. 
         [0039]    From the outlet  110  of the centrifugal pump  40 , the water is pumped to the engine intercooler by pipeline  42 . The purpose of the intercooler is to cool the air coming from the compressor side of the turbocharger of the engine  10 . As the air is passed through the turbocharger the air is heated. By passing the air through the intercooler  90 , this air is cooled by the water in the intercooler  90  from the pipeline  42 . This results in the air being cooled as well as the water being heated at the same time. This is the second source of heat. 
         [0040]    The water continues from the intercooler  90  to the engine coolant/water heat exchanger portion  60  by pipeline  62 . The heat exchanger portion  60  allows the heat from the hot coolant passing from pipe  68  to heat exchanger portion  66  to be transferred to the water at heat exchanger portion  60 . Sufficient volume of water is pumped to keep the engine coolant operating within its specified temperature range. This is the third source of heat. 
         [0041]    After exiting the engine heat exchanger portion  60 , the water is pumped to the exhaust heat exchanger  50  by pipeline  64 . In this exchanger, the hot exhaust from the engine from pipeline  14  which can be at 700° F. (400° C.) is allowed to flow across a series of pipes that the water flows through in the engine exhaust heat exchanger  50 . This exchanger is sized so that the exhaust output temperature from pipe  54  is at approximately 70° F. (20°-25° C.). From the outlet of this heat exchanger  50  the water is pumped back to the inlet  100  of the trash pump  40  by pipeline  52 , where the heated water mixes with colder water entering the system. This is the fourth source of heat. 
         [0042]    The foregoing description should be considered as illustrative only of the principles of the invention. Since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.