DK145353B - Combustion engine system with a pressurized, water-cooled engine - Google Patents

Description

The invention relates to an internal combustion engine plant having a pressurized, water-cooled engine and of the kind specified in the preamble of claim 1.

5 It is known from DE-AS 24 43 055 or DD-PS 103 071 for energy recovery from the waste gases and cooling water in a motor by means of steam circuits in a plant of the kind in question to make a division into a high pressure circuit heated by the waste gases, and another 10 circuit, LT, with lower pressure and lower temperature, which last circuit utilizes the waste heat from the cooling water. The working medium in these steam circuits, preferably water, is thereby heated and evaporated and, as the case may be, superheated before serving to operate at least one turbine * and is again condensed while the turbine operates an electric generator or other working machine. Recovery of the compression heat in the charging air is not contemplated by such plants.

20 In "Schiff- & Hafen / Kommandobrucke" 29 (1977 * booklet 5> page 488/489), a plant is described in which all the waste heat sources - waste gas, charge air and cooling water - are connected over a common steam circuit, 25 whose working medium after one another passes a heat exchanger for energy transfer from the engine cooling water, a charge air cooler for the compressed charge air and finally a waste gas heated waste heat boiler.

30 The energy recovery in this plant is relatively small as all three waste heat sources are flowed through the same amount of working medium. In particular, the recovery of heat from the charge air cooler and from the engine cooling water circuit is therefore by no means optimal.

The present invention aims to improve a plant of the first of the species described above so that as much energy as possible can be recovered and that the total thermal efficiency of the plant 5 is increased as the temperature level of the recovered heat under the supervision of the labor-expansion must be as high as possible.

This is achieved according to the invention in that the plant is designed as defined in the characterizing part of claim 1.

As with the engine in the "Schiff- und Hafen / Kommandobrucke", the compression heat in the charging air forms an additional available waste heat source. However, in contrast to the known plant, the independent heating and steam generation by means of the two waste heat sources in the LT steam circuit not only allow in each of the two circuits to individually adjust the produced steam in terms of quantity, pressure and temperature to the energy quantities, 20 are available in the individual wastewater sources, but further within the LT steam circuit, the two wastewater sources can be charged air and cooling water, which are at different temperature levels, and in which further, since the working medium is in different phases, the heat transfer conditions are different. exploited optimally.

The use of the hot water cooling of the engine known per se, which use, however, has so far not been utilized in practice, e.g. because of the risk of a possible vapor blistering or because of the higher temperature level of the cylinders cooled through it, enables an improvement of the energy recovery in steps.

The temperature increase of the cooling water 35 thus obtained raises the waste heat which can be recovered from the cooling of the engine to a temperature level which corresponds very well with the temperatures of utilization of the compression heat in the charge air which can be obtained on the steam side without extreme effort for the heat exchanger surfaces.

5 By using a hot water cooling circuit which is completely separate from the steam circuit for the sake of circulating water and which is completely adapted to the needs of the engine in terms of its pressure level, it becomes possible to summarize the waste heat utilization of the cooling water and from the charge air in a common steam circuit. - with independent heat exchanger systems for the heating and evaporation of the working medium.

Advantageous measures for dividing and controlling the working medium flow through the heat transfer systems for the heat sources retroactive to the engine, i.e. the cooling water cooling and the charging-air cooling are subject to requirements, since the cooling water outlet temperature and / or the charge air inlet temperature of the engine important for engine operation are used as control sizes.

By controlling the heat dissipated in the capacitor from the second steam circuit, a sufficient heat removal can be ensured from the cooling water in the engine and / or from the charging air, e.g. also if any disturbances occur at the steam turbine or the turbine fails.

On the other hand, the necessary heat transfer can also be ensured when in the second steam circuit, preferably in the flow direction of the working medium, before the parallel heat exchanger for the waste heat is added an additional cooler.

If the temperature level is favorable, in addition to the turbines for producing mechanical work, it is possible to inject one or more independent heat consumers in one of the circuits or in both circuits in a known manner. heat consumers, which are only connected to the steam systems indirectly over heat exchangers, thereby achieving an improvement in the thermal overall efficiency of the plant.

The invention is further explained with reference to the drawing, which shows an embodiment of the internal combustion engine plant.

A schematically shown motor 1 belongs to a charging group whose charge air blower 3 sucks air from the atmosphere 15 through a conduit 4 and transports the air through a conduit 6 to the motor 1. In the conduit 6 there is a charge air cooler 7 for the compressed air.

The charge air blower 5 is driven by a waste gas turbine 8 20 over a shaft 10, the hot exhaust gases from the engine 1 being fed to the turbine 8 through a line 9 and after expansion in the turbine 8 passing through a line 11 into which a heat exchanger is inserted. 12th

25

The heat exchanger 12 serves as the evaporator and superheater for the working medium in a conventional steam circuit 13 which operates at relatively high pressures and serves to utilize waste gas heat. In a circuit system, a first pump transports 15 working media, e.g. water, from a boiler 14- over a preheater 16 to evaporator tubes in the waste gas heated heat exchanger 12 and from there back to the steam room in the boiler 14 ·. In a preheater 16, the working medium delivers heat to the condensate which is pumped from a condenser 17 to the boiler 14-. The steam generated in the evaporator tubes is supplied from the boiler 14 to the superheat part of the heat exchanger 12 and reaches from it into a steam turbine 18 which, for example, drives an electric generator 19 · 5

The steam expanded in the turbine 18 then flows to the capacitor 17, from which another pump 20 transports the condensate for heating in the preheater 16 and then to the water space in the boiler 14. Since this system 13 for utilization of waste gas vapors is a known and many times used interior design, the operation is not described in detail here.

At engine 1 there is further shown a cooling water circuit 15 running 21 containing a cooler 22, a pump 23 and an artificial high tank 24. The hot water cooling known per se differs from the conventional cooling systems in that it operates at temperatures above 100 ° CFex. For example, the cooling water can leave the motor 1 at about 120 ° C and flow into a back-cooler 22 and cool within it about 10 ° to 110 ° C and then, transported by the pump 22, flow back to the motor 1.

Since evaporation must be prevented in this cooling water circuit, the circuit system is under an overpressure which, by means of the artificial high tank 24 and with the use of compressed air, e.g. is held at 5 ata.

As a heat-absorbing medium, in the hot water reflux condenser 22 and in the charge air cooler 7, a working medium in a second steam circuit 25 is provided. In the illustrated embodiment, it contains a feed pump 26, of which working medium, generally water, is conveyed from a capacitor 27 to a branch point 28 In this point 35 the water flow is divided into two parallel flow systems 29 and 60, one of which contains heat-absorbing secondary pipe hoses in the cooler 7, while the other contains such hoses in the auxiliary cooler 22. Water in these two subsystems of the heat dissipated from the coolers converted to saturated steam.

The partial currents, which are again joined at a point 31¾ to a steam turbine 32, are expanded therein and in addition to this the capacitor 27 · The turbine 32 drives e.g. an electric generator 33 ·

The heat of condensation to be removed from the capacitor 27 is taken up by a system 34- only schematically shown cooling water 34. However, in the illustrated embodiment 15 open system 34-, in addition to cooling hoses 35 in the capacitor 27, contains a pump 36 on whose pressure side there is discharged. branched a shunt or outlet line 38 provided with an adjustable shut-off and throttle member 37 · The means 37 and line 38 are intended to enable a regulation of the cooling performance of the capacitor 27, as will be described below.

In the illustrated embodiment of the system, the working medium amount is divided into the two steam generating subsystems 39 25 and 30 by means of adjustable throttle means 39 and 4-0, to which adjustment signals from a control or control device 4-1 are passed over lines 4-2. and 4-3. A third setting signal is passed over a line 44- to the throttle member 37 in the shunt 30 or the drain line 38 of the condenser cooling circuit 34 ·.

The control or control means 4-1 receive as input signals measurement values from two temperature sensors 4-5 35 and 4-6 by which the cooling water outlet temperature 7 and the charge air inlet temperature of the engine "are measured.

These temperatures, which e.g. advantageously can be maintained at a constant size, which serves as a control size in the apparatus 4-1, which also has no means shown for a scale value setting for said temperatures.

As already mentioned, a capacitor whose cooling performance is adjustable can advantageously be built and dimensioned to ensure sufficient cooling of the cooling water and of the charge air to the engine 1 should disturbances or failure of the steam turbine J2 occur. . On the other hand, in some circumstances, it is also convenient for this task to insert an additional, adjustable cooler 4-7 into the steam circuit 25, as indicated in the drawing between the pump 26 and the branch point 28. The cooler 4-7 is provided. regulating its cooling performance e.g. on its refrigerant side 4-8 provided with an adjustable shunt line 50 over a throttle member 4-9. serve the same signal by which the cooling performance of capacitor 27 is also changed.

The operation of the regulation for the division of working methods must be explained by means of an example. Starting from an equilibrium state, it is assumed that the temperature sensor 46 shows an excessive temperature of the charge air. For this release from the set shell value, the system responds e.g. with a swirling of the member 40 and an opening of the member 39, thereby changing the division of the working medium into the two conduit systems 29 and 30 and adding a greater amount of "coolant" to the air cooler 7-

However, with these interventions, the equilibrium present in the 33 in the wiring system 30 for heat removal from the cooling water of the engine 1 is disturbed. This disturbance is countered by the apparatus 4-1 by a simultaneous swirling of the means 37, thereby increasing the cooling water flow through the capacitor 27 and decreasing the temperature of the water flowing to the coolers 7 and 22. Also, with a smaller amount of "coolant" flowing, the heat removal necessary for maintaining the desired temperature of the cooling water is thereby ensured.

10

In order to clarify the difference between the first steam cycle for waste gas heat recovery and the second steam circuit of the plant according to the invention, at appropriate dimensioning of the systems, temperatures and pressure are applied to the drawing at some points of the said circuits. Also, for the same sizing of the plant, the effects of the charge air and hot water cooling are estimated, and the temperatures thereby occurring at the inlet and outlet from the coolers, 20 7 and 22 in the working medium and in the steam stream are recorded.

The explained embodiment illustrates and illustrates how partly the hot water cooling and the charge air cooling can be simply and conveniently coupled to improve the overall effect of the system with the steam circuit 25 according to the invention.

Furthermore, the steam turbines 18 and 32 can be connected to operate a simple generator on a shaft. It is also conceivable to conduct both heat transfer systems 7 and 22 to one boiler for evaporating the working medium.

Also, the two capacitors 17 and 27 as well as the pumps 20 and 26 can in principle be combined into a single system.

35 In the latter case, additional control and control means are then necessary for an appropriate volume distribution of the two arising sub flows.

9 145353

In addition, it is conceivable that energy for 5 heating purposes can be derived in a known manner from one of the steam circuits or from both of them, e.g. by appropriate bottling in the turbines concerned after partial expansion.

Claims (3)

145353 PATEHTEEiT 1. Combustion engine system with a pressurized, water-cooled engine, furthermore having at least one charge group in which the charge air line contains at least one air cooler, and with steam circuits in which waste heat from the engine serves 5 for heating and evaporating the working medium which at least a partial steam turbine is supplied for at least one working capacity expansion, whereby in a known manner for waste heat utilization from the waste gases a first steam circuit having a higher 10. pressure and temperature level is inserted and for utilizing the waste heat in the cooling water a second steam circuit with a lower pressure and temperature level, characterized in that compressed charge air and cooling water in separate heat transfer systems (7, 22) serve as heat sources in the low pressure circuit (25) for heating and evaporation of the working medium and that the cooling water circuit (21) from the engine is designed as a hot water circuit which is under pressure and has cooling water temperatures above 100 ° C. 20 Installation according to claim 1, characterized in that the working medium in the low pressure circuit (25) is divided on the charge air cooler (7) and the cooling water return cooler (22) depending on the temperature of the cooled charging air at the outlet of the charge air cooler (7) and / or the temperature of the cooling water at the outlet of the engine (1). System according to claim 2, characterized in that for each subset of the divided working medium there is a separate feed pump. h. Installation according to one of claims 1 to 3, characterized in that the cooling performance of the capacitor