JPH10259758A - Thermal engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the energy efficiency by flowing the hot gas of the normal pressure or the pressure close thereto into a turbine to achieve the work, exchanging the heat of the hot gas leaving the turbine with cooling air to drop the temperature of the gas, and flowing the gas into a compressor to generate the output. SOLUTION: The gas 3 of high temperature and normal pressure is introduced in a turbine T to achieve the work, and the gas 4 which completes the work and is discharged flows into a heat exchanger HX, and the temperature is dropped to the normal temperature or the temperature close thereto through the heat exchange with the cooling air. After the gas 1 whose temperature is dropped is fed to a compressor C to rotate it, the gas is discharged outside. The turbine T can be driven with the gas of normal pressure by arranging the compressor C on the downstream side of the turbine T, and the difference between the output of the turbine T and the input required by the compressor C is taken out as the engine output. The gas to be used includes the exhaust gas from the engine and the hot gas generated in treatment of the refuse.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention can improve the energy use efficiency when exhaust heat can be used such as gas turbines, vehicle engines, industrial reciprocating engines, or incineration of waste. Further, the present invention can be used as a refrigerator using air, that is, an air cycle.

[0002]

2. Description of the Related Art Power is obtained by utilizing exhaust heat of a gas having a low pressure, usually through a steam turbine or a water heater. When operating as a refrigerator, heat is supplied from a compressor to heat exchange. However, the temperature coefficient of flow is lowered into the turbine, but it is difficult to lower the temperature to room temperature at the turbine inlet.

[0003]

In utilizing a heat source of a high-pressure gas at almost normal pressure, which is not high in pressure, the prior art of converting a liquid to steam or hot water requires a condenser and requires a complicated system. Become. Alternatively, the exhaust heat can be recovered by a turbine without using a liquid. However, if the turbine is placed directly at the exhaust port of a vehicle engine, for example, a relatively large back pressure is applied, which impairs the performance of the original engine. The present invention overcomes these drawbacks and provides efficient waste heat utilization with a simple system. On the other hand, in the present invention, it is intended to improve the coefficient of performance of the refrigeration cycle by using gas at room temperature instead of exhaust heat.

[0004]

FIG. 1 is a conceptual diagram corresponding to claim 1 of the present invention, and FIG. 2 is a temperature T / entropy S diagram showing an operating state of gas. High-temperature and normal-pressure gas flows into the turbine T, and the temperature is reduced to a normal temperature or a temperature close to the normal temperature by the heat exchanger HX, flows to the compressor C, and is discharged to the outside. The turbine can be operated with the gas at normal pressure because the compressor is at the rear, and the difference between the output of the turbine and the input required by the compressor is taken out as the engine output. As the gas for the turbine, exhaust gas from various forms of engines and gas turbines may be used. Alternatively, a high-temperature but low-pressure gas generated by dust treatment can be used. This will be described with reference to FIG. 2. When the gas having the temperature T and entropy S in the state 3 passes through the turbine, the state 4 is set. When the heat is removed by the heat exchanger, the state changes from 4 to 1, and the compressor is pressurized and heated to 2 and discharged to the outside world. As described in claim 2, when room temperature gas flows into the turbine instead of high temperature gas, the turbine can operate as a refrigerator. In this case, it is necessary to add the input from another institution, which is insufficient from the outside.

[0005] When it is difficult to recover energy and convert it to shaft power using a normal method such as exhaust heat from a car engine, the exhaust gas is used and compressed by a heat exchanger HX as shown in FIG. The temperature of the gas that has passed through the machine C is raised and flows into the turbine T to obtain the shaft output by utilizing the difference between the input of the compressor and the output of the turbine. This device PAS corresponds to claim 3. Both of the devices according to claims 1 and 3 require the input of a starting input from the outside until the output and input of the turbine and the compressor are balanced, that is, idling, and are the same as the operation procedure of a general gas turbine.

[0006]

The high pressure gas at normal pressure cannot be used unless it is converted into steam or hot water, but in the present invention, it can be directly used as power only by heat exchange without conversion into steam or the like. When operating as a refrigerator, the turbine inlet is always at or near room temperature, that is, the outside air temperature, and does not depend on the performance of the heat exchanger at the time of inflow.

[0007]

FIG. 4 shows a case where the apparatus TG according to the first aspect of the present invention is used in combination with a gas turbine. In this figure, B is a combustor, HX is a heat exchanger, C is a compressor, T
Is a turbine. FIG. 5 shows the operation state of the gas. G1
The air in the state of is sucked and compressed to G2 and G2 to G
Up to 5 ', the temperature is increased by regeneration using the heat of the exhaust gas, and the temperature from G5' to G3 is further increased by combustion. When this gas passes through the turbine, it becomes air G4 at normal pressure and high temperature. This is referred to as the state of T3 again. The temperature of the turbine TG of the device TG according to the first aspect of the present invention is reduced to the state of T4. This hot gas is further reduced to G6 'and further to T1 by heat exchange.
The heat generated in the process from T4 to T6 'is used to raise the gas in the gas turbine from G2 to G5'. G6 '
From T1 to T1. T1 to T2
Is pressurized by a compressor and discharged to the outside world. In this cycle diagram, as shown in FIG. 5, the portion close to the normal temperature has a case where the intermediate cooling of the compressor is performed by the gas turbine alone. Such a form is thermodynamically calculated and the result is shown in FIG. In this figure, the vertical axis represents the output ΔT _WTG by the device TG of the present invention in units of temperature, and the horizontal axis represents the expansion ratio π _r accompanying the TG passing through the turbine. When the heat exchange efficiency of TG is set to 1.0 and the heat exchange efficiency at the time of regeneration to the gas turbine is changed to three types of 0.8, 0.4, and 0, and the TG compressor is intercooled And calculated separately. Here, the heat exchange efficiency is, as generally known, the ratio of the actual heat transfer amount to the maximum possible heat transfer amount. In the figure, η _e is the adiabatic efficiency of the gas turbine and TG elements, which is 0.7
A value of zero indicates that all gas turbine and TG compressors and turbines are operating at 70% adiabatic efficiency. Here, the heat insulation efficiency of the element is changed by two types to 0.7
0, 0.75 was calculated. In each case, it was found that an output was obtained from the device TG of the present invention.

FIG. 7 shows an apparatus TG according to the first aspect of the present invention.
The case where a normal air cycle refrigerator is directly connected in order to utilize the output of FIG. The corresponding temperature T / entropy S diagram is shown in FIG. In the refrigerator, the ratio of the required input to the refrigeration capacity, that is, the coefficient of performance COP is important. The adiabatic efficiency η _{e of the} element is changed by two types (0.70, 0.75) and the heat exchanger efficiency ε _GR for regeneration to a gas turbine
Three of the relationship between the temperature difference △ T _c of (0.8,0.4, play no) varied COP and air cycle inlet and outlet was calculated based on the equation of thermodynamics is FIG. While the dashed line indicates only the air cycle, the coefficient of performance COP is dramatically improved under any conditions.

FIG. 10 shows a conceptual diagram when the apparatus GT of the present invention described in claim 2 is used as a refrigerator, and FIG. 11 shows a corresponding temperature T / entropy S diagram. The air in the state of 3 is expanded by the turbine to lower the temperature, exchange heat with the outside, and raise the temperature again from the state of 4 to 1. The cold external air obtained by heat exchange can be used for cooling or freezing. 12 and 13 show a comparison between a normal air cycle (AIRCYCLE) and TG with respect to the coefficient of performance COP by performing thermodynamic calculations.
It is. FIG. 12 compares the coefficient of performance COP with respect to changes in the adiabatic efficiencies ηc and ηt (ηc = ηt) of the compressor and the turbine. The temperature efficiency of heat exchange is ηr =
0.7. The TG according to the present invention has a higher COP than a conventional air cycle even if the heat insulation efficiency of the element is poor. TG is more advantageous than an air cycle in view of the fact that it is unlikely that the adiabatic efficiency of the element of 0.8 or more can be expected in a small compressor or turbine from the current aerodynamic design technology. FIG.
Shows the superiority of TG to the temperature efficiency ηr of the heat exchanger. In the calculation, ηc = ηt = 0.75 and pressure ratio π = 2.0. Considering that it is difficult to think that a temperature efficiency of 0.8 or more is practically possible, even when the temperature efficiency is poor, TG
Has the same advantage.

An apparatus PAS according to the invention as defined in claim 3
FIG. 14 is a conceptual diagram showing a case in which is applied to a vehicle engine to operate as auxiliary power utilizing waste heat to increase the economical efficiency of a vehicle cooler. Although the above-described TG may be used as a refrigerator, a case where a normal air cycle is connected will be described here for the sake of simplicity. FIG. 15 shows the corresponding temperature T.
Although it is an entropy S diagram, it exchanges heat with high-temperature exhaust gas, raises the temperature of the gas in the PAS from P2 to P3, becomes P4 after passing through the turbine, and is discharged. The output obtained by this and the output of the engine are added to operate the air cycle. FIG. 16 shows a thermodynamic calculation performed on such a system. In this figure, ECOP is a newly defined economic coefficient of performance. In general, the coefficient of performance COP is defined by the ratio of the refrigeration capacity and the input required for the refrigeration. However, in this case, the energy generated by the PAS is converted from the input required for the refrigeration because the waste gas is used as it is. The value obtained by subtracting the coefficient of performance is defined as the economic coefficient of performance ECOP. That is, unlike the physically strict COP, the coefficient of performance was examined from an economic viewpoint. In the figure, η _Pc and η _Tc are the adiabatic efficiency of the compressor and turbine of the PAS. Similarly, η _Cc and η _Ct are the adiabatic efficiency of the compressor and turbine of the air cycle. ΔT
c is the temperature drop due to the air cycle. It can be seen from the figure that the use of PAS can improve the economic coefficient of performance of the air cycle.

FIG. 17 shows an example in which the apparatus TG of the present invention is applied to a waste disposal facility. In this case, an auxiliary power Motor is required instead of the gas turbine or the engine.

FIG. 18 shows an example in which the apparatus TG of the present invention is applied to a garbage incinerator and linked to a steam turbine. In this figure, Pump indicates a pump and Con indicates a condenser. The utilization of exhaust heat is changed from the conventional two stages to three stages, and the highest temperature part of the system is first used in the apparatus TG of the present invention, and the system is put into the boiler in a state where the temperature is lowered to some extent. Conventionally, if a boiler is placed at a high temperature, corrosion will occur due to the material, so that the temperature has been lowered by cooling with water or the like.

FIG. 1 shows a case where the apparatus PAS according to claim 3 is used in a garbage incinerator instead of the apparatus TG according to claim 1 of the present invention.
9

[0014]

In the apparatus TG according to the second aspect of the present invention, since gas is first introduced into the turbine, a heat exchange efficiency of 100%, which is generally difficult to achieve, is always guaranteed at the time of inflow. In the case of high-temperature gas, 100 to 150
Since there is a temperature drop of about degree, it is advantageous to select the material of the heat exchanger that follows. In the equation of thermodynamics, the pressure is calculated in the form of a pressure ratio. Therefore, when the ratio is the same, the negative pressure is structurally advantageous because the absolute value of the pressure difference is small.

FIGS. 7, 8 and 9 show the coefficient of performance C of the air cycle.
The effect that the OP has been increased by the device TG of the present invention will be described below. COP = Q / W is generally defined when the work of W is required to obtain the refrigerating capacity of Q. To become the gas turbine alone efficiency E as the put device in cycle diagram as shown in FIG. 8 as if performed intercooling of the present invention is increased to E _t. Therefore COP is improved from the relationship of the _{COP = Q / (W-G} (E t -E)) to. In the above equation, G is the amount of heat of the input gas. If the ratio QE / W input and cooling capacity if the gas turbine is used to drive only the refrigerator without the power generation is improved _{QE t / W G (E t} -E)
Only gas calories can be saved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of claim 1.

FIG. 2 is a temperature T / entropy-S diagram

FIG. 3 is a conceptual diagram of claim 2;

FIG. 4 shows a device T according to claim 1, in combination with a gas turbine.
Conceptual diagram when using G

FIG. 5 is a diagram of temperature T and entropy S

FIG. 6 is a diagram showing a relationship between an output and an expansion ratio.

FIG. 7 is a conceptual diagram in which the device TG of the present invention is incorporated in a gas turbine.

FIG. 8 is a diagram of temperature T and entropy S

FIG. 9 is a diagram showing a relationship between a temperature drop and a coefficient of performance by a refrigerator.

FIG. 10 is a conceptual diagram of an apparatus according to claim 2;

FIG. 11 is a diagram of temperature T and entropy S

FIG. 12: Relationship between coefficient of performance and element efficiency

FIG. 13 shows a relationship between the temperature efficiency and the coefficient of performance when the compression ratio and the element efficiency are fixed.

FIG. 14 is a conceptual diagram when the device PAS of claim 3 is used as auxiliary power for a vehicle.

FIG. 15 is a diagram of temperature T and entropy S

FIG. 16: Relationship between temperature drop and economic coefficient of performance

FIG. 17 is a conceptual diagram when the device TG of claim 1 is used in an incinerator.

FIG. 18 is a conceptual diagram when the device TG according to claim 1 is used in front of a steam engine.

FIG. 19 is a conceptual diagram when the apparatus PAS according to claim 3 is used in an incinerator.

[Explanation of symbols]

T is a turbine or temperature HX is a heat exchanger C is a compressor S is entropy TG is a device according to claims 1 and 2 PAS is a device according to claim 3 η _e is element efficiency of a turbine and a compressor △ _Tc is the amount of temperature drop Pom is the pump Con is the condenser B is the combustor COP is the coefficient of performance ECOP is the economic coefficient of performance ηc and ηt are the compressor and turbine insulation efficiency ε _GR is the heat exchange efficiency π is the pressure ratio Or expansion ratio

Claims (3)

[Claims] An apparatus characterized in that a high-temperature gas at or near normal pressure flows into a turbine and heat is exchanged after the turbine exits to lower the gas temperature and flow into a compressor to obtain an output. 2. A gas at a normal temperature or a temperature close to the normal temperature flows into the turbine, and after the turbine exits, heat exchange is performed to raise the temperature of the gas and flow into the compressor, so that the output of the apparatus of claim 1 or other general power is supplied. An apparatus characterized by being operated as a refrigerator by utilizing. 3. A gas at a normal temperature or a temperature close to the normal temperature is sucked from a compressor and heat-exchanged with a low-density external high-temperature gas having a low pressure, such as exhaust heat of a car engine, to raise the temperature of the internal gas. Apparatus characterized by obtaining shaft power in a turbine.