JPH0850063A - Calorimeter system - Google Patents

Abstract

PURPOSE:To provide a compact, inexpensive system without flow resistance having a simple constitution, wherein the concentrations and the flow rates of ice slurry are obtained based on the propagating time of ultrasonic wave propagated through the ice slurry on the upstream/downstream sides of a heat exchanger in which the ice slurry is the heat medium. CONSTITUTION:An upstream-side flow tube 1, through which ice slurry 9 flows, is connected on the upstream side of a heat exchanger 3. A downstream-side flow tube 2, through which ice slurry 1-flows, is connected on the downstream side. The pairs of ultrasonic-wave transceivers 5 and 6 and 7 and 8 are attached to the flow tubes 1 and 2 at an angle phi with respect to the flow-tube axis O-O and mounted at an interval L being provided. The transceivers 5 and 6 and 7 and 8 are connected to a computing unit 4. The ultrasonic wave is transmitted and received through the transceivers 5 and 6 and 7 and 8 with the computing unit 4, and the sound speeds in the ice slurries 9 and 10 flowing through the flow tubes 1 and 2 are measured based on the propagating time. The concentration of the ice is obtained from the sound speed. The mass flow rate of the ice is computed based on the flow rates of the ice slurries, and the quantity of cold heat consumed in the heat exchanger 3 can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a calorimeter system, and more particularly to a propagation time in which ultrasonic waves propagate the amount of heat consumed in a heat exchanger using ice slurry as a heat medium in the ice slurry. The present invention relates to a calorimeter system which is calculated on the basis of the ice concentration and the ice slurry flow rate calculated by using as a parameter.

[0002]

2. Description of the Related Art District heating and cooling is usually performed by a system that supplies a heat source from an energy center in which a cooling and heating device is installed to a heat source center and further supplies the heat source of the heat source center to a customer. In district heating and cooling, hot water or steam is used as a heat source for heating, and cold water is conventionally used as a heat source for cooling. In a conventional cooling system using cold water, cold water of about 7 ° C. is used as a heat medium, which is supplied to a heat exchanger, and when the cold water flows out of the heat exchanger, it is heated by the amount of heat exchanged, It was recovered as water heated to 13 ° C.

In the conventional cooling using the cold water for such district cooling and heating, since the temperature difference before and after the heat exchanger of water as a refrigerant is small, it is necessary to increase the flow rate of the cold water in order to increase the amount of cold heat. As a result, due to the limitation of the flow velocity, the cold water pipe has a large diameter, which causes a problem that the equipment cost becomes expensive.
Therefore, it has been attempted to use not only cold water but also a eutectic mixture of water and ice (ice slurry) as a cooling heat source for cooling.

Since the latent heat of melting of ice is much larger than the specific heat of water, the cooling efficiency is good, and the pipe for carrying the ice slurry has the advantage of having a small diameter. Other problems such as efficiently transporting the ice slurry without adhering to the inside of the cold water pipe and knowing the ice concentration in the ice slurry in order to measure the amount of cold heat occur.

Conventionally, as a means for measuring the ice concentration, a method of measuring the pressure acting on the bottom of a container having a predetermined volume containing ice slurry and measuring the ice concentration as a function of the pressure, or a Coriolis flowmeter There is a method of measuring the density of the ice slurry by using, and there are many methods such as a method using ultrasonic waves.

In JP-A-5-340862, an ice concentration measuring device is attached between an ice heat storage tank in which the ice slurry flows and a heat exchanger, and the ice concentration in the ice slurry measured by the ice concentration measuring device is attached. (IPF: Ice Packing Facto
r) A technique is disclosed in which the IPF is kept constant by mixing water with the ice slurry flowing out from the ice heat storage tank so that the IPF becomes a constant value by a signal. The ice concentration measuring device obtains the IPF by measuring the static pressure acting on the bottom surface of the container, into which the ice slurry is introduced, with a pressure gauge to determine the magnitude of the static pressure when the ice slurry in the container reaches a certain level. It is a method.

Further, the present applicant has previously proposed a calorimeter for measuring the amount of cold heat of a heat exchanger using ice slurry as a heat medium. This calorimeter is equipped with a Coriolis mass flowmeter that can measure the density of ice slurry on the upstream and downstream sides of the heat exchanger, calculates the mass of ice melted in the heat exchanger, and multiplies this by the latent heat of melting of ice. This is based on the principle of measuring the amount of cold exchange heat per unit time.

[0008]

[Patent Document 1] Japanese Patent Application Laid-Open No. 5-34086
The IPF measurement method according to Japanese Patent Laid-Open No. 2 is based on the pressure gauge signal of the ice concentration measuring device, and the IP in the flow tube through which the ice slurry flows.
The present invention relates to a method of controlling the amount of water in the ice slurry so that the F concentration becomes constant. However, this method requires an additional element of an ice concentration measuring device consisting of a long container and a pressure gauge, so that the device is large. Be in shape. In addition, in order to measure the amount of cold exchange by the heat exchanger using this device, another ice concentration measuring device is installed downstream of the heat exchanger, and the mass of ice melted in the heat exchanger is calculated. Because it is necessary to
Further, there is a problem that the device becomes large.

Further, in the method of measuring the density of the ice slurry by the Coriolis flowmeter, the whole measuring device is small, and the amount of cold heat can be measured with high accuracy. However, in district cooling, the diameter of the pipe through which the ice slurry flows becomes large. For example, when the pipe diameter is 200 mm or more, the Coriolis flowmeter attached becomes large and the Coriolis flowmeter is used for district cooling. It is inappropriate to do so.

The present invention has been made in view of the above-mentioned circumstances, and provides an IPF measuring device having a simple structure, a small size, and no flow resistance. Further, the IPF measuring device is provided on the upstream and downstream sides of a heat exchanger. It is an object of the present invention to provide a calorie meter system for cooling and arranging, which is simple in structure, small in size, and inexpensive.

[0011]

In order to achieve the above object, the present invention provides (1) a heat exchanger using ice slurry as a heat medium, and ice connected to the upstream side and the downstream side of the heat exchanger. An upstream flow pipe and a downstream flow pipe through which the slurry flows, and upstream and downstream ultrasonic waves mounted on the respective pipe walls of the upstream flow pipe and the downstream flow pipe at a predetermined angle with respect to the flow pipe axis. From the propagation time of the ultrasonic waves propagating in the ice slurry between the transducer and the upstream and downstream ultrasonic transducers, the concentration and flow rate of the ice slurry flowing in the upstream flow pipe and the downstream flow pipe, respectively, And a calculator for calculating the amount of heat consumed by the heat exchanger based on the concentration and flow rate of the ice slurry and the ice density and latent heat known in advance, and (2) above ( In 1), the upstream and downstream ultrasonic transducers It is characterized in that it has several pairs.

[0012]

[Operation] An ultrasonic flow rate measuring device by an ultrasonic propagation time difference method is provided in a flow tube through which ice slurry flows. Since the temperature of the ice slurry is constant (0 ° C.), and the sound velocity in water and ice at 0 ° C. is known, the ice concentration can be obtained from the sound velocity detected by the ultrasonic flow rate measuring device. Once the ice concentration is determined,
Since the density of ice at 0 ° C. is constant, the mass flow rate of ice can be calculated from the flow rate of ice slurry measured in the ultrasonic flow meter device. By mounting such an ultrasonic flow meter device on the upstream and downstream of the heat exchanger, the amount of cold heat consumed in the heat exchanger can be obtained as the amount of heat of melting ice.

[0013]

【Example】

Embodiment 1 (corresponding to claim 1) FIG. 1 is a block diagram for explaining an embodiment of a calorimeter system according to the present invention, in which 1 is an upstream flow pipe and 2 is a downstream flow pipe. 3 is a heat exchanger, 4 is a calculator,
5, 6 and 7, 8 are ultrasonic wave transceivers, and 9, 10 are ice slurries.

The calorimeter system shown in FIG.
The upstream flow pipe 1 having a cross-sectional area A through which the ice slurry 9 flows is connected to the upstream side of the heat exchanger 3, and the downstream flow pipe 2 having a cross-sectional area A through which the ice slurry 10 flows is connected to the downstream side. In the upstream flow pipe 1 and the downstream flow pipe 2, a pair of ultrasonic wave transmitters / receivers 5, 6 and 7, 8 attached at an angle φ with respect to the flow pipe axis OO are separated by a distance L. It is installed.
The ultrasonic wave transmitters / receivers 5, 6 and 7, 8 are connected to the arithmetic unit 4.

Next, the principle of calorie measurement by the calorimeter system having the above configuration will be described. The upstream flow tube 1 through which the ice slurry 9 flows and the ultrasonic wave transmitters / receivers 5 and 6 mounted on the upstream measurement tube 1 constitute an upstream ultrasonic flow meter by the propagation time difference method. Similarly, ice slurry 1
The downstream flow pipe 2 in which 0 flows and the ultrasonic wave transmitter / receiver mounted on the downstream measurement pipe 2 constitute a downstream ultrasonic flow meter by the propagation time difference method.

In the computing unit 4, ultrasonic waves are transmitted to and received from the ultrasonic wave transmitters / receivers 5 and 6 forming a pair, and the sound velocity C of ultrasonic waves propagating in the ice slurry 9 flowing in the upstream flow tube 1 is transmitted. ₁ and the volumetric flow rate Q ₁ are measured, and ultrasonic waves are further transmitted / received to / from the ultrasonic wave transmitters / receivers 7 and 8, and the ice slurry 1 flowing in the downstream flow pipe 2
It has a flow velocity flow rate measuring means for measuring the sound velocity C ₂ and volume flow rate Q ₂ of the ultrasonic waves propagating in the zero and a cold heat amount calculating means described below.

Measuring propagation time differences by the propagation time difference method is well known. For example, looking at the upstream flow tube 1, assuming that the flow velocity of the ice slurry 9 is V and the sound velocity in the ice slurry 9 is C ₁ , the flow velocity V and the ultrasonic propagation time between the ultrasonic transducers 5 → 6 in the forward direction. T _{5. 6} and the flow velocity V and the opposite direction of the ultrasonic wave propagation time of the ultrasonic transducer ₆ → ₅ T 6. 5 is given by the following equation.

[0018]

[Equation 1]

Next, the operation of the arithmetic unit 4 will be described. (I) Not all of the ice in the ice slurry 9 flowing through the upstream flow tube 1 is melted in the heat exchanger 3, and the ice slurry 1 flows through the downstream flow tube 2
When forming a stream of zero. X the ice concentration in the ice slurry 9
_1% when the ice concentration in the ice slurry 10 to _2% x, the speed of sound upstream flow pipe acoustic velocity C ₁ in 1, the ice in the sound velocity C _2, 0 ° C. the downstream flow pipe 2 C _i (= 3,230 m / s) ... known Sound velocity in water at 0 ° C. C _w (= 1,402 m / s) ...

[0020]

[Equation 2]

Assuming that the flow velocity in the upstream flow tube 1 obtained by the equation (3) is V ₁ and the cross-sectional area of the upstream flow tube 1 and the downstream flow tube 2 is A, the volume flow rate Q ₁ is Q ₁ = AV ₁ (9) Similarly, when the flow velocity in the downstream flow pipe 2 is V ₂ , the volumetric flow rate Q ₂ is Q ₂ = AV ₂ (10). When the ice density at 0 ° C. is 917 kg / m ³ , the mass flow rate Q _{Mi1 of} ice flowing in the upstream flow tube 1 and the mass flow rate Q _{Mi2 of} ice flowing in the downstream flow tube 2 are _calculated by the following equations. .

[0022]

(Equation 3)

From equations (11) and (12), the amount of cold heat E ₁ consumed in the heat exchanger 3 per hour is 79.7 times the latent heat of ice.
As kcal / kg, E ₁ = (Q _Mi1 −Q _Mi2 ) × 79.7 = 731 (Q ₁ x ₁ −Q ₂ x ₂ ) (kcal / h) (13) it can. (II) All the ice in the ice slurry 9 flowing through the upstream flow tube 1 is melted in the heat exchanger 3, and the downstream flow rate 2 becomes T ₂ ° C (0 ° C <0 ° C
When flowing as water with T ₂ <30 ° C. The temperature C ₂ of water at T ₂ ° C is represented by C ₂ = 1.402 + aT ₂ −bT ₂ ² (m / s) (a and b are constants) (14) Q ₂ = AC ₂ (15). Therefore, when the specific heat of water is 4.186 kcal / kg, the amount of cold heat E ₂ consumed in the heat exchanger 3 is E ₂ = 731Q ₁ x from (13), (14), (15) It is represented by ₁ + 4.186Q ₂ T ₂ (kcal / h) (16), and the calorific value is calculated by the calculator 4 according to the equation (16).

According to the calorimeter system of the first embodiment, the upstream flow pipe 1 through which the ice slurry 9 flows and the downstream flow pipe 2 through which the ice slurry 10 flows are both ultrasonic transducers 5, 6 and 7, 8. In addition, the ultrasonic wave transmitters / receivers 5, 6 and 7, 8 do not project into the upper and lower flow pipes 1 and 2, so that the flow of ice slurry against It is possible to provide a calorimeter which is simple and highly reliable, and which is particularly suitable for a large diameter and a flow tube.

Embodiment 2 (corresponding to claim 2) When the upstream flow pipe 1 has a large diameter, the fluid in the flow pipe is relatively large,
Since the frictional resistance is small, the flow of the ice slurry 9 flowing in the upstream flow pipe 1 is easily affected by the shape of the upstream pipe of the upstream flow pipe 1, and the ice concentration is not always uniform. Since the flow velocity measurement by ultrasonic waves is performed based on the propagation time of the ultrasonic waves on the line connecting the ultrasonic transducers 5 and 6 in the flow tube, the flow velocity distribution in the upstream flow tube 1 is If the axis is asymmetrical or there is a swirl component, the flow velocity measurement accuracy will decrease. In the case of the downstream flow pipe 2, since the heat exchanger 3 is provided on the upstream side, the flow velocity distribution is likely to be axially asymmetric, and it is difficult to measure the flow velocity with high accuracy. Further, when the ice concentration is not uniform, the calculation result of the ice concentration does not always show the average value only by the sound velocity measurement by only one set of the transducers.

In the second embodiment, a plurality of pairs of ultrasonic transducers are provided in the flow tube so as not to be influenced by the flow velocity distribution in the flow velocity measurement and to calculate the average ice concentration even when the ice concentration is not uniform. It is attached to average a plurality of flow velocity measurement values and ice concentration values to improve accuracy.

FIG. 2 is a sectional view taken along the line A--A shown in FIG. 1 for explaining the second embodiment. In the figure, 11, 12 and 13, 14 are ultrasonic wave transmitting / receiving pairs. A vessel,
The same reference numerals as those in FIG. 1 are attached to the portions having the same functions as those in FIG.

The ultrasonic wave transmitters / receivers 11, 12 and 13, 14 shown in FIG. 2 are the ultrasonic wave transmitters / receivers 5, 6 shown in FIG.
In contrast to the ultrasonic wave transmitters / receivers 5 and 6, the upstream flow tube 1 and the ultrasonic wave transducers 5 and 6 are mounted so as to equally divide the cross section of the upstream flow tube 1. It has an angle of 60 °.

The flow velocity of the ice slurry 9 flowing in the upstream flow pipe 1 is such that the ultrasonic wave transmitters / receivers 5, 6 and 11, 12 and 13,
It is calculated by averaging the flow velocities measured based on the time difference method according to the above equation (4) of 14. These operations are performed by the calculator 4
Done by Similarly, a plurality of pairs of ultrasonic transducers are attached to the downstream flow tube 2. Also in the calculation of the ice concentration, the averaged ice concentration is obtained by averaging the ice concentrations measured in a plurality of pairs.

According to the second embodiment, it is possible to measure the flow velocity and the ice concentration with high accuracy even if the flow of the ice slurry in the flow tube is an asymmetric flow. Therefore, the calorie calculation accuracy is also improved.

[0031]

As is apparent from the above description, the present invention has the following effects. (1) Effect corresponding to claim 1: The concentration of ice in the ice slurry is determined by an ultrasonic flow meter having a simple structure, and the amount of heat consumed by the heat exchanger corresponds to the mass of ice melted by the heat exchanger. Since it is calculated as the amount of heat to be generated, it has only one set of simple ultrasonic flowmeters. Therefore, a calorimeter system with a simple structure and a low cost can be provided, which is particularly suitable for a large-diameter flow pipe. (2) Effect corresponding to claim 2: A plurality of pairs of ultrasonic wave transmitters / receivers are attached to the flow tube through which the ice slurry flows so as to divide the flow tube cross section into a plurality of sections, and measurement is performed with each ultrasonic wave transmitter / receiver. Since the calculated flow velocity and ice concentration are averaged, it is possible to measure the flow velocity that is not affected by the flow velocity distribution, and to measure the average ice concentration even when the ice concentration is not uniform.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating an embodiment of a calorimeter system according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1 for explaining a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Upstream flow pipe, 2 ... Downstream flow pipe, 3 ... Heat exchanger, 4 ...
Arithmetic unit, 5, 6 and 7, 8 ... Ultrasonic wave transceiver, 9, 1
0 ... Ice slurry, 11, 12 and 13, 14 ... Each pair of ultrasonic transducers.

Claims (2)

[Claims] 1. A heat exchanger using ice slurry as a heat medium,
The upstream flow pipe and the downstream flow pipe connected to the upstream side and the downstream side of the heat exchanger, through which the ice slurry flows, and the pipe wall of each of the upstream flow pipe and the downstream flow pipe have a predetermined size with respect to the flow pipe axis. From the upstream and downstream ultrasonic wave transmitters / receivers mounted at an angle and the propagation time of ultrasonic waves propagating in the ice slurry between the upstream and downstream ultrasonic wave transmitters / receivers, the upstream flow tube and Calculation of calculating the concentration and flow rate of the ice slurry flowing through the downstream flow tube, and calculating the amount of heat consumed by the heat exchanger based on the concentration and flow rate of the ice slurry and the previously known ice density and latent heat. A calorimeter system characterized by consisting of a vessel. 2. The calorimeter system according to claim 1, wherein a plurality of pairs of the upstream and downstream ultrasonic wave transmitters / receivers are provided.