Constraint

Introduction

Engineering heater, cooler, burner, boiler, etc., etc., the heat equipment, etc., is working near the regulation, The reversible multi-change process of multiplex index n = 0 is idealization of the actual compression process. Due to the constant pressure, the technical power value is zero, indicating that the working pressure is stably flowing through equipment such as heat exchanger, and the mechanical energy of thermal energy transformation is all used to maintain the work. flow. The enthalpy variation of any process is equal to the enthalpy change of the temperature change process. The process equation is:

p = value, P ₁ = p ₂

according to P = set value and Determining the relationship between the initial and final parameters:

is a proportional volume of the gas during the compression process is proportional to the thermodynamic temperature.

P-V Figure and T-S Figure

The equipage process line is shown in Figure 1 "P-V] of the final pressure process and T-S Figure. The constant pressure process line is a horizontal straight line on the PV map; a curve is a curve on the TS map, and the default value is similar to the heat capacity, and the slope of the correction line is more Flat.

Related Calculation

Due to P = set, the process work of the compression process is:

For the ideal gas, the process function of the regulation process can be further represented. In order to:

indicated that the gas constant R _g value of the ideal gas is equal to 1 kg gas in the temperature rise of 1K during the compression process.

process heat can be drawn according to the first parsing of thermodynamics:

, any temperature inhaled during the compression process is equal to the intensive increase, or the heat of the release is equal to . The heat or enthalpy difference of the regulation process can also be calculated by means of a controlled heat capacity, ie:

application

constant pressure heating for piston internal combustion engine

Internal inside of the regular heating is also known as the Di Seal cycle, its PV diagram and TS diagram are shown in Figure 2, "Di Siel cycle PV map and TS map". 1-2 is a fixed entropy compression process, 2-3 is a compression process, and 3-4 is a fixed entropy expansion process, 4-1 is a capacitive exothermic process. The ideal circulation efficiency of the regulation is improved with the increase of the compression ratio; reduced as an increase in the expensive ratio.

Gas turbine device The Ideal Circulation

reference air standard hypothesis, the gas turbine device work cycle can be simplified as an ideal cycle consisting of four reversible processes, as shown in FIG. Among them, 1-2 is a heat insulating compression process; 2-3 is a constant pressure heating process; 3-4 is an adiabatic expansion process; 4-1 is a regular pressure release process. This circulation is called the ideal cycle of the tank heating, also known as the Bretton cycle.

• Compression Process Opposition (1)

• Compression Process Album (1)

The thermal efficiency of the Ideal circulation of the controlled heating depends on the initial temperature and final temperature of the heat-insulating compression in the compressor, or mainly depending on the cycle boost ratio, and increases with cyclic increase In addition, it is also related to the numerical value of the thermal insulation index of the work quality, and has nothing to do with the cycle temperature.

For thermal power units, in addition to high efficiency, it is also possible that the power of the unit quality is in the cycle (also known than cycle work), and for some occasions, such as aviation, Ships, etc., the latter indicator is especially important.

In the Ideal Cycle of the regulation, when the cycle is increased, as the cycle boost ratio is improved, the net power of the unit quality in the cycle is not getting bigger and larger. Instead, there is an optimal boost ratio, making the net power output of the cycle.