CN101153823A - Ultrasonic steam flowmeter - Google Patents

Abstract

The invention discloses an ultrasonic steam flow meter, which belongs to an metrical instrument and comprises a central control unit and a measuring circuit which has the functions of emitting and receiving and comprises an emitter A, a converter A, an emitter B, a converter B, a converter control switch and a time measuring circuit. The input end of the central control unit is connected with a measuring circuit that controls the ultrasonic sensor, a calendar display, a keyboard, a printer port and various communication ports; the central controller produces different ultrasonic signals in media at different temperatures by controlling the switches of the emitters and the converters of the ultrasonic sensor; the central control unit collects, analyses and calculates the quantity of heat and flow by controlling the time measuring circuit. The positive effect of the invention is that the time that the steam flow is measured, the caloric value of the steam can be calculated accurately.

Description

Ultrasonic steam flowmeter

Technical field

The present invention relates to the industrial steam gauging instrument, specifically is to calculate a kind of ultrasonic steam flowmeter that shows the steam calorific value.

Background technology

The tradition steam-flow meter has in the industrial technology product of steam measurement a lot, as be used for pipeline metering, the boiler export metering is medium, but do not relate to the metering of the calorie value of the steam of flowing through in these metering outfits, all can only pay when causing the steam user to use high-quality steam (steam that heat content is high) and low-quality steam (steam that heat content is low) according to volumetric flow rate, can't embody the value of calorie value in the steam, both do not meet market discipline, do not met the requirement of building a conservation-minded society yet.

Summary of the invention

The objective of the invention is to overcome the above-mentioned shortcoming of prior art, a kind of ultrasonic steam flowmeter is provided.The calorie value that it has the steam of flowing through calculates, the flow metering function, the electronic product that promptly has high quality steam and inferior quality vapor recognition.

Technical scheme of the present invention is as follows: a kind of ultrasonic steam flowmeter, it is characterized in that, the metering circuit that it comprises central controller, is made up of transmitter A, converter A, transmitter B, converter B, converter gauge tap and time measuring circuit with the function of transmitting and receiving, the input end of central controller connects metering circuit, perpetual calendar display, keyboard, printer interface and the various communication interface of control ultrasonic sensor; Central processing unit passes through the control to the transmitter and the converter switch of ultrasonic sensor, make the different ultrasonic signal of generation in the medium under the different temperatures, gather, analyze and calculate heat, flow by central processing unit control time metering circuit at last.

The heat Calculation formula is:

$Q={\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_1}{q}^m\mathrm{\Δh}{d}^{\mathrm{\τ}}={\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_1}\mathrm{\ρ}{q}_v\mathrm{\Δhd\τ}$

In the formula: Q---the heat (J or wh) that discharges or absorb;

The mass rate (kg/h) of qm---the water of the calorimeter of flowing through;

The volumetric flow rate (m3/h) of qv---the water of the calorimeter of flowing through;

The density (kg/m3) of ρ---the water of the calorimeter of flowing through;

Δ h---under the entrance and exit temperature of heat-exchange system, the enthalpy of water poor (J/kg);

τ---the time (h).

Owing to adopt technique scheme, central processing unit passes through the control to the transmitter and the converter switch of ultrasonic sensor, make the different ultrasonic signal of generation in the medium under the different temperatures, gather, analyze and calculate heat by central processing unit control time metering circuit at last.The precision of the technical program superelevation, ultra-long time are on active service, super low-power consumption accurately obtain data such as desired flow rates, flow or heat rapidly, and all data are shown by LCD, simultaneously flowmeter have automatic preservation data, etc. function.

Good effect of the present invention is: when measuring steam flow, can accurately calculate the calorific value that shows steam.

Description of drawings

Below in conjunction with drawings and Examples the present invention is described in further detail.

Fig. 1 is a circuit block diagram of the present invention;

Fig. 2-the 1st, the main program flow block diagram;

Fig. 2-the 2nd, the Interrupt Process subroutine flow chart

Among the figure: 1, central controller, 2, calendar, 3, keyboard, 4, printer interface, 5, the LCD liquid crystal display, 6, transmitter gauge tap, 7, transmitter A, 8, transmitter B, 9, converter B, 10, converter gauge tap, 11, converter A, 12, time measuring circuit, 13, communication output.

Embodiment

As shown in Figure 1, central controller 1 adopts the super low power consuming single chip processor of MSP430 series, the transmitter with sensor measurement function that transmitter A7 and transmitter B8 adopt General Electric Apparatus Co.(U.S.A.) to produce, time measuring circuit 12 adopts 0.1ns ultrahigh resolution, the superelevation linearity and ultra-high stable degree CPLD time measuring circuit.In central controller 1, store the data in Fig. 2-1, Fig. 2-2 programs and the table 1.Controller 1 is gathered vapor (steam) temperature and pressure data by the transmitter gauge tap 6 and the converter gauge tap 10 of control ultrasonic transmitter, and converses related data according to table 1, calculates the steam calorific value with the heat Calculation formula.Controller realizes that by clock 2. while of perpetual calendar controller provides LCD5 to show and various communication output function 13 accurately simultaneously.

Table 1: the pressure of saturated vapor and the relation of temperature

Temperature ℃	22	24	26	28	30	32	34	36	38	40
											Water vapour pressure MPa	0.00264	0.00298	0.00336	0.00378	0.00424	0.00475	0.00532	0.00594	0.00662	0.00738
Corresponding vacuum tightness MPa	0.09869	0.09835	0.09797	0.09755	0.09709	0.09658	0.09601	0.09539	0.09471	0.09395

Temperature ℃	42	44	46	48	50	52	54	56	58	60
											Water vapour pressure MPa	O.00820	0.00910	0.01009	0.01116	0.01234	0.01361	0.01500	0.01651	0.01815	0.01992
Corresponding vacuum tightness MPa	O.09313	0.09223	0.09124	0.09017	0.08899	0.08772	0.08633	0.08482	0.08318	0.08141
											Temperature ℃	62	64	66	68	70	72	74	76	78	80
Water vapour pressure MPa	0.02184	0.02391	0.02615	0.02856	0.03116	0.03396	0.03696	0.04019	0.04365	0.04736
											Corresponding vacuum tightness MPa	0.07949	0.07742	0.07518	0.07277	0.07017	0.06737	0.06437	0.06114	0.05768	0.05397
Temperature ℃	82	84	86	88	90	92	94	96	98	100
											Water vapour pressure MPa	0.05133	0.05557	0.06011	0.06495	0.07011	0.07561	0.08146	0.08769	0.09430	0.10133
Corresponding vacuum tightness MPa	0.05000	0.04576	0.04122	0.03638	0.03122	0.02572	0.01987	0.01364	0.00703	0
											Temperature ℃	102	104	106	108	110	112	114	116	118	120
Water vapour pressure MPa	0.10878	0.11668	0.12504	0.13390	0.14327	0.15316	0.16362	0.17465	0.18628	0.19854
											Temperature ℃	122	124	126	128	130	132	134	136	138	140
Water vapour pressure MPa	0.21145	0.22504	0.23933	0.25435	0.27013	0.27831	0.30407	0.32229	0.34138	0.36138

Claims (3)

1. ultrasonic steam flowmeter, it is characterized in that, the metering circuit that it comprises central controller (1), is made up of transmitter A (7), converter A (11), transmitter B (8), converter B (9), converter gauge tap (10) and time measuring circuit (12) with the function of transmitting and receiving, the input end of central controller (1) connects metering circuit, perpetual calendar display (2), keyboard (3), printer interface (4) and the various communication interface of control ultrasonic sensor; Central processing unit passes through the control to the transmitter and the converter switch of ultrasonic sensor, make the different ultrasonic signal of generation in the medium under the different temperatures, gather, analyze and calculate heat, flow by central processing unit control time metering circuit at last.

2. ultrasonic steam flowmeter according to claim 1 is characterized in that, the heat Calculation formula is:

$Q={\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_1}{q}^m\mathrm{\Δhd\τ}={\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_1}\mathrm{\ρ}{q}_v\mathrm{\Δhd\τ}$

In the formula: Q---the heat (J or wh) that discharges or absorb;

The mass rate (kg/h) of qm---the water of the calorimeter of flowing through;

The volumetric flow rate (m3/h) of qv---the water of the calorimeter of flowing through;

The density (kg/m3) of ρ---the water of the calorimeter of flowing through;

Δ h---under the entrance and exit temperature of heat-exchange system, the enthalpy of water poor (J/kg);

τ---the time (h).

3. ultrasonic steam flowmeter according to claim 1 is characterized in that, central controller 1 adopts the super low power consuming single chip processor of MSP430 series.

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