DE3111620C2 - - Google Patents

Description

The invention relates to a portable Ver steamer for flameless heating of a ver liquid gas by utilizing the waste heat of a Internal combustion engine, in which

• a) with the internal combustion engine a pump Conveying the liquefied gas in the drive connection,
• b) the internal combustion engine by one in one Circulating coolant, that through a cooling jacket of combustion motors flows, is cooled,
• c) the coolant circuit a cooling medium heat exchanger that contains one on the one hand from the coolant and on the other hand in Heat exchange with that of the vaporized Gas is flowed through, between Ver internal combustion engine and the coolant inlet of the Coolant heat exchanger is a coolant flow and between the coolant outlet of the Coolant heat exchanger and the ver internal combustion engine formed a coolant return is  
• d) in the coolant circuit in series with the Coolant heat exchanger further heat exchangers exchangers are arranged, through which heat, those in others, through the internal combustion engine driven devices is generated on the coolant is transferable, and
• e) an exhaust gas heat exchanger for the transmission of Heat from the exhaust gases of the internal combustion engine to the gas to be evaporated from the exhaust gas of the Internal combustion engine is flowed through.

Numerous ares are required for oil and gas drilling large quantities of nitrogen gas. These Operations are both at land as well performed on offshore drilling. It deals processes such as breaking open below formation by foam, acid treatment, the advancement of devices and the like by the Pipe string or through the annular space between the pipe strand and borehole casing that contain nitrogen buffering when testing the drill pipe, pressure test the insulation of the annulus between Pipe string and borehole piping to problems by preventing paraffin from precipitating Propulsion of proppants in perforation and Cutting operations, reducing the density of working fluids brought into the borehole, the displacement of borehole fluid from the Pipe string in perforation operations around the one drifting material in the perforation arises in the formation due to excessive hydro to avoid static pressure in the borehole Placement of corrosion inhibitors by nebulization tion of the inhibitor with nitrogen, the deletion of  Fire at boreholes and others. The present Invention can be used in any of these operations Application come.

A special operation on which the following Revelation refers to breaking up an underground formation by pumping a liquid under very high pressure. In the there is breakdown fluid pumped down the well often from one with the help of nitrogen gas put, foamed gel.

The one needed to break up with foam Nitrogen is usually turned around at temperatures

• -196 ° C stored in liquid form.

In the course of this breakup by foam prevailing pressure the nitrogen changes at approx.

• -129 ° C its liquid in gaseous state. It it is therefore desirable to increase the nitrogen gas overheat that the ge pumped into the hole foamed liquid essentially ambient temperature. The reason for this is very low temperatures otherwise occurring from Nitrogen foam caused numerous disturbances on the mechanical equipment.

The nitrogen heating works for land drilling device generally with an open flame. Problems however, arise from foam during break-open processes in offshore drilling. For security and vice versa The reasons for the exercise are on offshore drilling platforms open flames are generally not allowed. Therefore for the nitrogen a heating system is necessary which works without an open flame.  

A flameless, portable evaporator of this Art is known from US-PS 32 29 472. There becomes a liquid from an internal combustion engine pump driven, the liquefied nitrogen a tank through a coolant heat exchanger pumps. The coolant heat exchanger is from the cooling the internal combustion engine, in a circuit pumped through coolant. The scorch voltage motor drives a liquid at the same time vortex brake with adjustable back pressure. That from the coolant heat exchanger for combustion Engine coolant flowing back flows through a Brake oil heat exchanger and an exhaust gas heat exchanger exchanger. In the former heat exchanger occurs the coolant in heat exchange with the heated Fluid from the fluidic brake. In the latter Heat exchanger, the coolant enters heat exchangers exchange with the hot exhaust gases of the combustion motors. The liquid brake can be used once the load and thus the temperature of the ver internal combustion engine can be changed in a controlled manner. The energy is destroyed in the fluid brake additionally via the brake oil heat exchanger transfer the coolant. Waste heat from the hot exhaust gases through the exhaust gas heat exchanger transferred to the coolant. The coolant is there this heat back to the thing to be vaporized and on gas to be heated.

DE-OS 29 42 565 is a portable, flameless vaporizer known, which is too evaporating and heating gas in a pipe snake flows through an air duct running. A fan creates an airflow of Ambient air through this air duct. In the air  the hot exhaust gases from a combustion process motors initiated, the a liquefied gas pump drives. The cooler is still in the air duct of the internal combustion engine and an oil cooler of the Hydraulic system arranged. The waste heat from the Exhaust gases, the coolant of the internal combustion engine and the hydraulic system is thus on the through conducted air. This air then gives warmth to the gas to be evaporated and heated (Nitrogen). The heat transfer using the ambient air as a heat transfer medium is bad, however. The performance of this ver dampfers is therefore limited.

DE-OS 27 49 903 shows a device for Evaporation of liquefied natural gas with improvements ter energy balance. A diesel engine drives you Generator for power generation. It is still a closed gas turbine cycle with nitrogen provided as a driving medium that a Gastur bine and contains a compressor. The gas turbines Circuit continues to contain immediately upstream from the gas turbine a heat exchanger, in which the nitrogen from the hot exhaust gases of the Diesel engine is heated. The one in the gas turbine Relaxed nitrogen is released by a recuperator passed and enters through an evaporator, in which he evaporates in heat exchange with that the liquefied natural gas occurs. The one from this Evaporating, strongly cooled nitrogen is compressed and ent by a compressor speaking warmed up again. The warmed up again Nitrogen flows through the recuperator to that preheated heat exchanger for heating through the exhaust gases of the diesel engine. There are further  towards heat exchangers provided in which the heat the coolant of the diesel engine and the lubricant oil to the liquefied natural gas.

By US-PS 40 31 705 is an additional drive for known an internal combustion engine that has a Overrunning clutch with the internal combustion engine couples. This additional drive is a steam powered engine operating in a closed works with a working medium, whose boiling point is below the boiling point of the Water lies. The working medium is from Waste heat from the internal combustion engine in two parallel Branches heated and so on the steam powered Given engine. One branch contains one Exhaust gas heat exchanger in which the working dium in heat exchange with the hot exhaust gases of the Combustion engine occurs. The other branch contains a coolant heat exchanger in which the Working medium in heat exchange with the coolant of the internal combustion engine occurs. It is here not about using a gas To vaporize the internal combustion engine flameless.

The state of the art therefore makes it necessary flameless nitrogen evaporator known. Corresponding devices according to the state of technology, however, have numerous disadvantages, especially as far as their ability is concerned Heat to evaporate large amounts of nitrogen generate, and in terms of their ability, the Amount of heat transferred to nitrogen and its corresponding temperature when entering the Controlling the borehole head precisely.  

The invention has for its object a Evaporators of the type defined at the outset form that even with changing and large volu min of the liquefied gas to be evaporated precise control of the heat input to the gas and hence its temperature at the evaporator outlet is guaranteed.

According to the invention, this object is achieved by that

• f) a second one, working independently of the first Tender internal combustion engine is provided is also cooled by the coolant, which by a cooling jacket of the second Internal combustion engine flows,
• g) both internal combustion engines in the common Coolant circuit with its cooling jackets parallel between the coolant flow and the coolant return are arranged,
• h) the exhaust gas heat exchanger in the flow path of the gas to be vaporized upstream of the cooling arranged medium heat exchanger and one on the part of the exhaust gases from both combustion motors and on the other hand in direct heat swap with that to be evaporated, ver liquid gas flows through,
• i) to the exhaust gas heat exchanger alone and the series connection of exhaust gas heat exchangers and coolant heat exchanger each one order management provided and each of these Bypass line from an adjustable ven til is mastered,  
• j) with the second internal combustion engine a ver changeable load device is connected, through which a variable load on the second internal combustion engine is exercisable, and
• k) heat in the coolant circuit is provided by which the in lost heat generated by the load device the coolant is transferable.

The flameless nitrogen evaporation device the present invention improves the device state of the art that they add a second internal combustion engine to the single purpose of additional heat generation Evaporation of the nitrogen provides. This second Internal combustion engine and its associated heat transfer system is like this with a first burn motor and the associated heat transfer system connected that the first combustion engine for nitrogen production in one can be generated by a single internal combustion engine Scope can be used, and that then for larger quantities of the second combustion engine acti be fourth and be in connection with that of first internal combustion engine working heat Transmission system for a complete heat transfer can provide enough nitrogen evaporate in these larger quantities and essential to over to environmental conditions heat.

Embodiments of the invention are explained below with reference to the accompanying drawings.

Fig. 1 is a plan view of a first embodiment of a nitrogen evaporator.

Fig. 2 is a side view of the nitrogen evaporator of FIG. 1st

Fig. 3 is a schematic flow diagram for the nitrogen in the nitrogen evaporator of FIG. 1st

Fig. 4 is a schematic flow diagram for the coolant in the nitrogen evaporator of FIG. 1st

Fig. 5 is a schematic flow diagram for the lubricant of the main pump, for the transmission oil and for the pressure medium in the nitrogen evaporator according to Fig. 1st

Fig. 6 is a section through the discharge fitting in connection with the bypass lines for the nitrogen in the nitrogen evaporator of FIG. 1st

Fig. 7 is a view of one of the mixing chambers in the nitrogen evaporator according to Fig.1.

Fig. 8 is a section along the line 8-8 in Fig. 7.

Fig. 9 is a section along the line 9-9 in Fig. 8.

Fig. 10 is a schematic flow diagram for the coolant in a two-th embodiment of the inventive nitrogen evaporator.

An evaporation system 10 for flameless Ver evaporation of liquefied nitrogen has a rectangular, portable slide frame 12 with opposite first and second sides 14 and 16 and opposite third and fourth sides 18 and 20. The evaporation system 10 is surrounded by a protective cage 21 (omitted in FIG. 1).

Installed in the frame 12 are first and second internal combustion engines 22 and 24 , preferably diesel engines. The internal combustion engines 22 and 24 are arranged in the frame 12 so that the respective axes of rotation 26 and 28 of the crankshafts of the internal combustion engines 22 and 24 are substantially parallel to the third and fourth sides 18 and 20 of the frame 12 . On the frame 12 is between the first internal combustion engine 22 and the second side 16 of the frame 12, a nitrogen pump 30th

The nitrogen pump 30 is driven by the first internal combustion engine 22 via a manual transmission 32 and a reduction gear 31 .

The manual transmission 32 is equipped with a known hydraulic transmission brake 33 , which works similarly to a torque converter, in which the transmission is loaded by the transmission brake, which depends on a controllable fluid level of the transmission fluid in the transmission brake. The higher the fluid level in the transmission brake, the greater the load.

The second internal combustion engine 24 has at its rear end a drive unit 34 for three pumps, with which a first, second and third hydraulic pump 36 , 38 and 40 , two of which can be seen in FIG. 1, are in drive connection.

As shown in Fig. 1, the exhaust systems of the engines 22 and 24 are connected to a heat exchanger 42 located between and above the engine Ren 22 and 24 exhaust gas nitrogen. The heat exchanger 42 is a device for direct heat transfer from the exhaust gases generated by the engines 22 and 24 to the nitrogen flowing through the inner tube of the heat exchanger 42 . The term "directly" is intended here to mean that the thermal energy is not transferred by any heat-transferring liquid between the exhaust gases and nitrogen.

For direct heat transfer from a cooling liquid to the nitrogen is a coolant-nitrogen heat exchanger 44 behind the second motor 24 near the fourth side 20 of the frame 12 .

On the back of the first and second motors 22 and 24 are near the third and fourth sides 18 and 20 of the frame 12, a first and second chamber 46 and 48 for mixing cooling liquid.

Above the manual transmission 32 there is a number of heat exchangers which transfer thermal energy from various sources of the evaporation system 10 to the cooling fluid circulating through the cooling device of the combustion engines 22 and 24 . These heat exchangers are as follows:

A first and second hydraulic cooler 50 and 52 are provided for transferring the thermal energy from a pressure medium conveyed by the pumps 36, 38 and 40 to the cooling liquid.

A transmission cooler 54 is provided for transferring the thermal energy from the transmission fluid circulating through the manual transmission 32 and its associated transmission brake 33 to the coolant.

First and second nitrogen pump coolers 56 and 58 are provided for transferring the thermal energy from a lubricant circulating through nitrogen pump 30 to the cooling liquid.

Fig. 3 shows a schematic flow diagram of the nitrogen system of the evaporation plant 10. The nitrogen pump 30 conveys liquid nitrogen from a storage container 60 . The reservoir 60 is not in the frame 12 . The stick material pump 30 is connected on the output side by an output line 62 to the inner tube of the heat exchanger 42 . As arrows 64 and 66 show, hot exhaust gases from internal combustion engines 22 and 24 are passed through the jacket of heat exchanger 42 . The liquid nitrogen from the pump 30 enters the heat exchanger 42 at a temperature of approximately -196 ° C. The heat generated by the heat exchanger 42 is approximately sufficient to evaporate the nitrogen, and the evaporated nitrogen then exits through a connecting line 68 at a temperature of approximately -129 ° C. from the heat exchanger.

The connecting line 68 leads the evaporated nitrogen into the inner tube of the cooling liquid-nitrogen heat exchanger 44th As arrows 70 and 72 show, warm cooling liquid is passed through the jacket of the heat exchanger 44 by the system shown in FIG. 4. The heat transferred from the cooling liquid to the evaporated nitrogen in the heat exchanger 44 overheats the evaporated nitrogen to approximately an ambient temperature of 21 ± 11 ° C. in the connecting line 73 leaving the heat exchanger 44 .

As shown in Fig. 3, the heat exchanger 42 and the heat exchanger 44 are arranged with respect to the flow direction of the nitrogen so that the exhaust gas nitrogen heat exchanger 42 is upstream from the cooling liquid nitrogen heat exchanger 44 is angeord net.

To bypass liquid nitrogen past the heat exchanger 42 , a first bypass line 74 is provided. In the first bypass line 74 , a manually operable control valve 76 is provided, which is a device for controlling the amount of liquid nitrogen bypassed by the exhaust gas nitrogen heat exchanger 42 , through which a controllable portion of the nitrogen can be bypassed.

In order to pass liquid nitrogen past both the exhaust gas nitrogen heat exchanger 42 and the cooling liquid nitrogen heat exchanger 44 , a second bypass line 78 is seen before. In the second bypass line 78 , a manually operable control valve 80 is arranged in the form of a needle valve so that the amount of liquid nitrogen passed through the second bypass line 78 can be controlled.

The first and second bypass lines 74 and 78 are connected in parallel, the second bypass line 78 being operated independently of the first bypass line 74 and liquid nitrogen can therefore be passed through either or both of the bypass lines. The discharge line 73 of the coolant-nitrogen heat exchanger 44 and the second bypass line 78 are both connected to a discharge fitting 82 .

82. Fig. 6 shows the flow connector in section. The dispensing fitting 82 has a first inlet 84 and 86 connected to the connecting line 73 and a second one connected to the bypass line 78 .

In the fitting 82 , a thermocouple 88 is arranged so that a temperature indicator (not shown) for measuring the temperature of the superheated nitrogen exiting the fitting 82 through its outlet 90 can be attached thereto. The outlet 90 is connected to a nitrogen discharge line 92 which directs the superheated nitrogen vapors to a device for foaming 96 where the nitrogen gas is used to prepare the gel solution to break up the formation. This gel solution is then passed through a connecting line 98 to the wellhead 100 of the respective hole.

With the connecting line 73 between the cooling liquid-nitrogen heat exchanger 44 and discharge fitting 82 are a safety valve 102 and

a connecting flange 104 connected to an access valve 106 .

Fig. 4 shows how the arrows 70 and 72 in Fig. 3, a schematic flow diagram for the through the jacket of the coolant-nitrogen heat exchanger 44 flowing coolant speed.

Fig. 4 shows schematically similar to Fig. 3, the cooling liquid-nitrogen heat exchanger 44th As the dashed arrows 68 and 73 show, the warm coolant enters the heat exchanger 44 through the connecting line and transfers heat in the heat exchanger 44 to the nitrogen flowing through the inner tube of the heat exchanger 44 , and a cooler coolant passes through the connecting line 72 from the heat exchanger 44 .

The other end of the connecting line 72 is attached to an inlet 108 on the inner tube of the hydraulic cooler 50 . An outlet 110 on the inner tube of the hydraulic cooler 50 is connected by a connecting line 114 to an inlet 112 on the inner tube of the second hydraulic cooler 52 .

An outlet 116 on the inner tube of the second hydraulic cooler 52 is connected by a connecting line 120 to the inlet 118 of the transmission cooler 54 . An outlet 122 on the inner tube of the transmission cooler 54 is connected to a connecting line 124 , which in turn is connected to hydraulically parallel connecting lines 126 and 128 , which lead to the inlets 130 and 132 on the inner tube of the first and second nitrogen pump coolers 56 and 58 , respectively.

An outlet 134 on the inner tube of the first nitrogen pump cooler 56 is connected by a connecting line 136 to a first inlet 137 of the first mixing chamber 46 . An outlet 138 on the inner tube of the second nitrogen pump cooler 58 is connected by a connecting line 140 to a first inlet 141 of the second mixing chamber 48 .

From a first outlet 142 of the mixing chamber 46 exits cooling liquid through a connecting line 144 . The other end of the connecting line 144 is connected to an inlet 146 on the cooling jacket of the first internal combustion engine 22 . The coolant then flows through the cooling jacket of the internal combustion engine 22 and leaves the cooling jacket through the outlets 148 and 150 . A connection line 152 is connected at one end to the outlets 148 and 150 and at the other end to a thermostatically controlled three-way valve 154 . A first outlet 156 of the three-way valve 154 leads coolant to a cooler 160 via a connecting line 158 . A second outlet 162 of the three-way valve 154 leads cooling liquid to a second inlet 166 of the first mixing chamber via a connecting line 164 . Depending on the temperature of the cooling liquid entering the thermostatically controlled three-way valve 154 , the cooling liquid is directed either to the first outlet 156 or to the second outlet 162 . If the coolant becomes too hot, it is directed to the first outlet 156 and to a conventional cooler 160 , where it is cooled by heat exchange with the air flowing outside the cooler 160 . Otherwise, the cooling liquid is led out to the second outlet 162 and to the second inlet 166 of the first mixing chamber 46 . The coolant conducted through the connecting line 158 to the cooler 160 enters the inner tube of the cooler 160 through the inlets 170 and 172 . This coolant then exits through an outlet 174 on the inner tube of the cooler 160 and is passed through a connecting line 176 to the inlet 146 of the cooling jacket of the first internal combustion engine 22 .

An overflow line 178 is connected to an overflow outlet 180 of the cooler 160 and an overflow outlet 182 of the first mixing chamber 46 . The overflow line 178 is connected to a first overflow tank 184 , from which a supplementary line 186 conducts cooling liquid to a supplementary inlet 188 of the first cooler 160 . The overflow tank 184 serves to vent the coolant and provides the necessary make-up liquid.

All of the cooling liquid that flows from the first mixing chamber 46 through the connecting line 144 to the internal combustion engine 22 or through the radiator 160 and then leads back to the internal combustion engine 22 finally returns, as described above, through the connecting line 164 to the second inlet 166 the mixing chamber 46 back. The cooling liquid entering through the second inlet 166 , just heated by the first internal combustion engine 22 , is mixed with the cooler cooling liquid entering through the first inlet 137 within the mixing chamber 46 . Part of this mixed cooling liquid consists of the cooling liquid previously described as emerging from the first outlet 142 of the mixing chamber 46 . A second part of the mixed cooling liquid in the mixing chamber 46 exits through the connecting line 192 from the second outlet 190 of the mixing chamber 46 .

In a preferred embodiment, the temperature of the cooling liquid entering through the first inlet 137 is approximately 71 to 77 ° C. The temperature of the cooling liquid passing through the second inlet 166 is approximately 88 ° C. The temperature of the cooling liquid emerging through the first and second outlet 142 and 190 is in each case approximately 82 ° C.

The mixing chamber 46 serves to increase the temperature of the cooling liquid passed into the cooling system of the first internal combustion engine 22 more than would be possible if there was no mixing chamber 46 and a direct connection between the connecting lines 136 and 144 . This helps to prevent hypothermia of the first internal combustion engine 22 and prevents the problems that occur inevitably when the internal combustion engine is under temperature.

The various connecting lines returning the cooling liquid from the internal combustion engines 22 and 24 to the heat exchanger 44 can generally be referred to as a coolant supply; and the various cooling liquids from the heat exchanger 44 to the first and second internal combustion engines 22 and 24 conductive connecting lines may be referred to as a coolant return.

The coolant return leading from the heat exchanger 44 to the combustion engines 22 and 24 is divided by a T-piece 125 into two parallel liquid flows. The two parallel liquid flows are combined again by a T-piece 204 in the coolant supply. The first and second internal combustion engines 22 and 24 are therefore connected in parallel between the coolant supply and the coolant return.

The mixing chamber 46 could be replaced by a conventional heat exchanger which does not mix the liquids flowing to and from the motor 22 , but because of the uniformity of the liquids and the insignificance of their temperature difference, a mixing chamber is preferable because, compared to a conventional heat exchanger with a jacket, it is preferable and inner tube of the same physical size, allows a significantly stronger heat exchange.

The connecting lines connecting the second mixing chamber 48 to the second internal combustion engine 24 are arranged in a manner similar to that described above between the first mixing chamber 46 and the first internal combustion engine 22 . The second mixing chamber 48 has a first inlet 141 and a second inlet 194 . It also has a first outlet 196 and a second outlet 198 . The second outlet 198 is connected to a connecting line 200 . The connecting lines 192 and 200 returning the cooling liquid from the mixing chambers 46 and 48 are both connected by a T-piece 204 to a common return line 202 .

The return line 202 is connected to a suction side of a coolant pump 206 . The outlet side of the coolant pump 206 is connected to the connecting line 70 , which is connected to the inlet on the jacket of the coolant-nitrogen heat exchanger 44 . The cooling liquid pump 206 is driven by a hydraulic motor.

Although not shown in FIG. 4, it is desirable to conduct a smaller portion of the warm coolant flow leaving the pump 206 through a heating jacket around the liquid end of the nitrogen pump 30 to heat it up.

FIGS. 7 to 9 show the details of construction of the mixing chamber 46. The second mixing chamber is constructed in the same way. Fig. 7 is an external view of the mixing chamber 46.

The mixing chamber 46 has a vertical, cylin drical housing 208 with which the inlets 137 and 166 and the outlets 142 and 190 are connected. At the upper end of the housing 208 , a cover 210 is placed through a fastening collar 212 . The overflow outlet 182 is attached to the cover 210 .

Fig. 8 shows a section along the line 8-8 in Fig. 7. A lower plate 214 seals the lower end of the cylindrical housing 208 . On the outer surface of the housing 208 , a first and a second fastening part 216 and 218 are attached to the frame 12 of the vaporization system 10 for its fastening.

A first, second and third baffle 220 , 222 and 224 are located within the housing 208 .

As the horizontal section of Fig. 9 taken along the line 9-9 in Fig. 8, the guide plates at two central, vertical parallel supports are mounted 226 and 228, which are used in rectangular cutouts in the guide plates.

The mixing chamber 46 operates as follows: the cooler coolant enters through the first inlet 137 and the warmer coolant enters through the second inlet 166 . Above the first baffle 220 , the two liquid streams begin to mix. When the mixed liquid flows down through the mixing chamber 46 to the outlets 142 and 190 , the direction of the liquid flow for thorough mixing is changed twice by the second and third baffles 222 and 224 so that the temperature of the two outlets 142 and 190 escapes liquid is essentially the same at both outlets.

FIG. 5 shows a schematic flow diagram for the liquids flowing through the jacket of the hydraulic coolers 50 and 52 , the transmission cooler 54 and the nitrogen pump coolers 56 and 58 . In order to clarify the correlation of the two drawings, the flow of the coolant through the inner tubes of these heat exchangers is similar to that shown in Fig. 4 in dashed lines.

In the lower part of FIG. 5, the three hydraulic pumps 36 , 38 and 40 operated by the second motor 24 are each connected to a common delivery line 232 on the output side. In order to control and change of the discharge pressure in the discharge pipe 232 in the discharge line 232 a controlled pressure relief valve 234 is disposed. The controlled pressure relief valve can be set to the back pressure desired for the discharge line 232 . At the start of the displacement pumps 226 , 228 and 230 , the pressure relief valve 234 remains closed for a very short time until the pressure in the discharge line 232 has reached its desired value for opening the pressure relief valve. At this point, the pressure relief valve opens and ensures constant back pressure against the displacement pumps 226, 228 and 230 at the setpoint.

In a (not shown) control panel on the frame 12 is a connected with the controlled pressure relief valve 234 so superordinate pressure relief valve that the setpoint setting of the controlled pressure relief valve 234 can be canceled and changed by operating the pressure relief valve located in the control panel. When the pressure medium passes through the pumps 36 , 38 and 40 and through the throttle point in the controlled pressure relief valve 234 , heat is generated and transferred to the pressure medium.

The pumps 36, 38 and 40 together with the controlled pressure relief valve 234 provide a variable load on the second internal combustion engine 24 , so that when the load on the second internal combustion engine 24 is increased by increasing the counter pressure controlled by the controlled pressure relief valve 234, that of the internal combustion engine 24 on the cooling liquid in the system shown in Fig. 4 and then in the coolant-nitrogen heat exchanger 44 from the coolant to the liquid nitrogen amount of heat is increased ver.

A connecting line 236 connects the ge controlled pressure relief valve 234 with an inlet 238 mantelsei term of the second hydraulic cooler 52nd A connecting line 240 connects the hydraulic cooler 52 to a jacket-side inlet 244 of the first hydraulic cooler 50 . A jacket-side outlet 246 of the first hydraulic cooler 50 is connected to a connecting line 248 . The connecting line 248 is connected to two parallel connecting lines 250 , 252 , which in turn are connected to a first and second filter 254 and 256 . The outlets of the filters 254 and 256 are connected to the connecting lines 258 and 260 , which in turn are connected to a common return line 262 .

The pumps 36 , 38 and 40 are on the corresponding suction sides 264 , 266 and 268 all connected to the return line 262 and complete the circuit of the pressure medium through the jacket of the hydraulic cooler 50 and 52 .

The return line 262 is connected by a connecting line 265 and by a check valve 267 to a hydraulic oil reservoir 263 . Another return line 269 for the pressure medium from a hydraulic motor (not shown) which operates the coolant pump 206 (see FIG. 4) connects between the check valve 267 and the connecting line 262 to the connecting line 265 .

The check valve 267 ensures a constant back pressure of approximately 1.5 bar in the connecting lines 265 and 269 and supplies the suction sides of the pumps 36 , 38 and 40 with pressure medium under constant pressure.

The middle part of FIG. 5 schematically represents the first internal combustion engine 22 , the manual transmission 32 and the transmission brake 33 .

An outlet 270 of the manual transmission 32 and the transmission brake 33 is connected on the suction side to the transmission fluid pump 272 by a connecting line 274 . The output line of the transmission fluid speed pump 272 is connected by a connecting line 278 to a jacket-side inlet 276 of the gear cooler 54 . A jacket-side outlet 280 of the transmission cooler 54 is connected to a connecting line 282 , the other end of which is connected to a filter 284 . The outlet of the filter 284 is connected to a return line 286 , which in turn is connected to an inlet 288 of the manual transmission 32 and the transmission brake 33 connected. Due to the friction occurring in the manual transmission 32 and in the transmission brake 33 , the transmission fluid is heated and the heat is transmitted through the transmission cooler 54 to the coolant.

The upper part of FIG. 5 shows the circulation of the lubricating oil of the nitrogen pump 30 . The lubricating oil manifold 290, the nitrogen pump schematically illustrates the lubricating oil to the various moving parts of the pump 30 nitrogen defending loin supply of lubricating oil represents. When flowing through the manifold 290, the lubricating oil is heated. Through a connecting line 292 , the lubricating oil is fed into the reduction gear 31 described above in connection with FIG. 1, which connects the manual gear 32 to the nitrogen pump 30 . The lubricating oil is then passed through a connecting line 294 from the reduction gear 31 to a lubricating oil reservoir 296 . A lubricating oil pump 298 is connected on the suction side to the lubricating oil reservoir 296 by a connecting line 300 . The discharge side of the lubricating oil pump 298 is connected by a connecting line 304 to a jacket-side inlet 302 of the first nitrogen pump cooler 56 . A jacket-side outlet 306 of the first nitrogen pump cooler 56 is connected by a connecting line 310 to a jacket-side inlet 308 of the second nitrogen pump cooler 58 . A jacket-side outlet 312 of the second nitrogen pump cooler 58 is connected to a connecting line 314 . The connecting line 314 is connected to an inlet of a filter 316 . The outlet of the filter 316 is connected by a connecting line 318 to the inlet of the lubricating oil distributor 290 of the nitrogen pump 30 and thus completes the circuit of the lubricating oil. A pressure relief valve 320 is connected by a connecting line 322 to the connecting line 314 , and the outlet of the pressure relief valve 320 is connected by a connecting line 324 to the lubricating oil reservoir 296 .

The described flameless nitrogen Ver steaming system works as follows:

For relatively low nitrogen flow rates, only the first internal combustion engine 22 needs to be used. The internal combustion engine 22 is started and drives the nitrogen pump 30 , which pumps the nitrogen through the system shown in FIG. 3. The flow rates of the nitrogen pumped by the nitrogen pump 30 are controlled by controlling the speed of the engine 22 and by adjusting the transmission 32 .

At the same time, the exhaust gases of the internal combustion engine 22 flow through the jacket of the exhaust gas nitrogen heat exchanger 42 and heat up the liquid nitrogen. If the exhaust gas-nitrogen heat exchanger 42 generates too much heat, it can be partially or completely bypassed by the bypass line 74 and the control valve 76 .

The nitrogen then flows into the coolant-nitrogen heat exchanger 44 , where it is further heated up by the heat transferred from the coolant. The exhaust gas nitrogen heat exchanger 42 and the coolant nitrogen heat exchanger 44 can both be bypassed by means of the second bypass line 78 and the control valve 80 . Observing the temperature indicator (not shown) connected to thermocouple 88 , control valves 76 and 80 , primarily valve 80 , can be actuated to fine tune the temperature of nitrogen flowing out of outlet 90 of dispensing assembly 82 .

A comprehensive, but less accurate setting of the nitrogen temperature can be achieved by changing the load on the transmission brake 33 by changing the load on the internal combustion engine 22 and, accordingly, the heat generated in the various heat exchangers. At the same time, of course, heat is transferred from the transmission 32 and the transmission fluid to the coolant through the transmission cooler 54 . In addition, in the nitrogen pump lubrication system shown in the upper part of FIG. 5, heat flows into the nitrogen pump coolers 56 and 58 .

When the systems connected to the first internal combustion engine 22 are no longer able to generate sufficient heat to vaporize the desired amounts of liquid nitrogen, the second internal combustion engine 24 is started up. The second internal combustion engine 24 is operated independently of the first internal combustion engine 22 , so that the second internal combustion engine 24 can optionally be used as an additional heat source in addition to the first internal combustion engine 22 if the amount of heat transferred from the first internal combustion engine 22 to the cooling liquid is insufficient to provide enough heat for heating the nitrogen to a desired temperature in the coolant nitrogen heat exchanger 44 .

When the second internal combustion engine 24 is started up , the amount of heat generated by it can be roughly adjusted by changing the back pressure on the pumps 36 , 38 and 40 and by the controlled pressure relief valve 234 . The fine adjustment of the temperature is achieved by means of the bypass line 78 and the control valve 80 .

The evaporation device 10 provides pumping rates in the total range of approximately 0.43 to 6.5 m ³ under normal conditions per hour at a pump pressure of approximately 1690 bar.

FIG. 10 shows another exemplary embodiment in which the pumps 226 , 228 and 230 and the adjoining system shown in the lower part of FIG. 5 are replaced by a fluidic vortex brake 400 which is operated by the second internal combustion engine 24 . The fluidic vortex brake is another device for changeable loading of the internal combustion engine 24 , so that when the load on the internal combustion engine 24 is increased, the amount of the internal combustion engine 24 to the cooling liquid and then from the cooling liquid in the cooling liquid to the nitrogen nitrogen heat exchanger 44 to the liquid nitrogen transferred heat is increased.

In the embodiment of FIG. 10, cooling liquid emerging from the jacket of the heat exchanger 44 is passed through a connecting line 402 to an inlet 404 of the fluidic brake 400 . The fluid vortex brake 400 acts like a low-efficiency centrifugal pump, thereby converting mechanical energy from the combustion engine 24 into heat in the coolant. The load exerted on the internal combustion engine 24 is in turn changed by the change in the counterpressure against which the fluidic brake 400 works. This is done by a back pressure valve 406 .

The cooling liquid emerging from the back pressure valve 406 has a pressure of approximately 0 bar and is passed through the connecting line 408 to a sump 410 .

From the sump 410 , the cooling liquid is fed via a suction line 412 to a pressure pump 414 , which increases the pressure of the cooling liquid to the level of approximately 0.55 bar required for the correct functioning of the rest of the system.

Via a connecting line 416 , the cooling liquid speed is passed from the pressure pump 414 to the inlet 118 of the transmission cooler 54 . The rest of the system shown in FIG. 10 is the same as that of FIG. 4.

Claims (1)

Portable evaporator for flameless heating of a liquefied gas by utilizing the heat from an internal combustion engine, in which

• a) a pump ( 30 ) for conveying the liquefied gas is in drive connection with the internal combustion engine ( 22 ),
• b) the internal combustion engine ( 22 ) is cooled by a coolant circulating in a coolant circuit and flowing through a cooling jacket of the internal combustion engine,
• c) the coolant circuit contains a coolant heat exchanger ( 44 ) which is flowed through on the one hand by the coolant and on the other hand in heat exchange therewith by the gas to be evaporated, whereby between the internal combustion engine ( 22 ) and the coolant inlet ( 70 ) of the coolant heat exchanger a coolant flow and a coolant return is formed between the coolant outlet ( 72 ) of the coolant heat exchanger ( 44 ) and the internal combustion engine ( 22 ),
• d) further heat exchangers are arranged in the coolant circuit in series with the coolant heat exchanger ( 44 ), by means of which heat generated in other devices ( 33 , 30 ) driven by the internal combustion engine ( 22 ) can be transferred to the coolant, and
• e) an exhaust gas heat exchanger ( 42 ) for the transfer of heat from the exhaust gases of the internal combustion engine ( 22 ) to the gas to be vaporized by the exhaust gas of the combustion engine ( 22 ) is characterized in that
• f) a second, of the first independently working internal combustion engine ( 24 ) is seen, which is also cooled by the coolant flowing through a cooling jacket of the second internal combustion engine ( 24 ),
• g) both internal combustion engines ( 22 , 24 ) are arranged in the common coolant circuit with their cooling jackets in parallel between the coolant flow and the coolant return,
• h) the exhaust gas heat exchanger ( 42 ) in the flow path of the gas to be vaporized current on from the coolant heat exchanger ( 44 ) and on the one hand from the exhaust gases of both internal combustion engines ( 22 , 24 ) and on the other hand in direct heat exchange therewith from the vaporized , liquefied gas flows through,
• i) to the exhaust gas heat exchanger ( 42 ) alone and to the series connection of exhaust gas heat exchanger ( 42 ) and coolant heat exchanger ( 44 ) each have a bypass line ( 74 , 78 ) and each of these bypass lines ( 74 , 78 ) by one an adjustable valve ( 76 , 80 ) is controlled,
• j) is connected to the second internal combustion engine (24) includes a variable load device (226- 234) by which a variable load on the second Ver brennungsmotor (24) can be exerted, and
• k) is provided exchanger in the coolant circuit, a heat from (50, 52) through which generated in the load device (226- 234) heat loss to the cooling medium is transferable.