JP3475394B2 - Method and apparatus for measuring heat density of hydrate slurry - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the total amount of latent heat and sensible heat, that is, the heat density, of a hydrate slurry containing a plurality of kinds of hydrate particles per unit weight or unit volume. . More specifically, the present invention relates to a heat density measuring method and apparatus capable of continuously measuring the heat density of the hydrate slurry as described above which is continuously distributed online.

[0002]

2. Description of the Related Art Conventionally, various technologies have been developed for storing cold heat, effectively utilizing waste heat from a factory, and other energies to save energy and reduce adverse effects on the environment. In such a technique, a technique has been developed in which cold heat is stored as latent heat, heat is stored effectively as a slurry having fluidity, and the transfer of cold energy is facilitated, and the energy required for the transfer of cold energy is also reduced. There is.

As a technique as described above, there is a technique in which cold heat is stored as ice, and the ice is made into particles to form a slurry with water. However, such a device requires a cold heat source of at least 0 ° C. or less to generate ice slurry, and there is a limit to improving the efficiency of such ice slurry generation.

Another technique is to cool an aqueous solution containing various guest compounds to generate hydrate particles and store heat as a hydrate slurry. Such a hydrate may be, for example, 12 °, depending on the type of guest compound.
There are various advantages such that it can be generated at a temperature of about C and can be generated by utilizing low temperature waste heat.

As a guest compound which forms such a hydrate, a tetra-n-butylammonium salt (hereinafter referred to as TB) is used.
AB)), tetra-iso-amyl ammonium salt, tetra-n-butyl phosphonium salt, tri-iso.
-Amyl sulfonium salts and the like. Also, gas hydrates such as methane and carbon dioxide may be used.

However, such hydrates, such as TB
It is known that the AB hydrate forms two kinds of hydrates, that is, a first hydrate and a second hydrate having different hydration numbers. The amount of latent heat is different from the thing. Also,
In the case of producing such a hydrate, the first hydrate is first produced, and the first hydrate is further converted into the second hydrate, and the solid in the produced hydrate slurry is produced. Phase ratio (hereinafter S
It is difficult to know the ratio of the first hydrate and the second hydrate in the solid phase even if the PFs are the same.

[0007] The hydrate slurry as described above is not only used as a heat storage medium, but in many cases, the hydrate slurry is circulated so that the hydrate slurry also serves as a cold heat carrier medium. In such a case, it is necessary to measure the amount of cold heat used on the load side, that is, the user side of cold heat. In this case, the amount of heat per unit weight or unit volume of this hydrate slurry Need to measure. However, the thermal density cannot be measured unless the ratio of the first hydrate to the second hydrate in the solid phase can be grasped as described above. Also, in the process of producing such a hydrate slurry, it is needless to say that the measurement of the heat density is necessary for controlling the plant and the like.

As a method for measuring such heat density, a so-called batch method is used in which a certain amount of a hydrate slurry is sampled, the hydrate is melted, and the heat density is measured from the amount of heat required for melting the hydrate. There is.

However, as described above, when the hydrate slurry is directly supplied to the user side or when the plant for producing the hydrate slurry is controlled, the batch type measuring method as described above is used. It was extremely inconvenient. For this reason, there has been a demand for the development of a method and an apparatus for continuously measuring the heat density of the hydrate slurry in circulation online, but up to now, no method and an apparatus which are practically satisfactory have been developed. .

[0010]

SUMMARY OF THE INVENTION The present invention has been made based on the above circumstances, and can continuously and online measure the heat density of a hydrate slurry containing a plurality of hydrates. It is an object of the present invention to provide a method and an apparatus for measuring the heat density of a hydrate slurry, which is simple and has a simple structure.

[0011]

The present invention according to claim 1 contains particles of a plurality of types of hydrates, the initial concentration of the aqueous solution is known, and the particles of each type of the hydrates described above. A method of measuring the heat density of a hydrate slurry of which the ratio of is unknown, the process of previously measuring the latent heat and sensible heat characteristics of each hydrate of the above-mentioned plurality of hydrates, The process of previously measuring the sensible heat characteristics of the aqueous solution, and the relationship between the ratio of the solid phase in the slurry of the hydrate and the temperature of the hydrate slurry for each of the plurality of hydrates And a step of preparing a pressure loss element in which the relationship between the solid phase ratio of the hydrate slurry and the flow rate and the pressure loss when the above hydrate slurry is circulated is measured in advance, The above hydrate slurry is passed through the above pressure loss element, and its flow rate and pressure loss And the process of measuring the temperature and the hydrate flow rate, pressure drop, temperature measured in the above process and the known values obtained in the above process from the solid phase in the hydrate slurry. And the ratio of each kind of hydrate in the solid phase, and the heat density of the hydrate slurry is calculated from the calculation result.

The relationship between the SPF and the viscosity of the hydrate slurry is as follows:
Due to the predetermined relationship, the SPF of the hydrate slurry can be calculated by measuring the flow rate of the hydrate slurry passing through the pressure drop element whose pressure loss is known and its differential pressure, that is, the pressure loss. It is also known that when there are multiple hydrates, the temperature of the hydrate slurry differs depending on the ratio of those hydrates in the solid phase. By measuring the temperature of the slurry, the ratio of hydrate types in the solid phase can be calculated. Therefore, from these calculation results,
The latent heat amount and the sensible heat amount of this hydrate slurry can be calculated, and the heat density of this hydrate slurry can be measured by this.

In such a method, the measuring process is simple, and the pressure loss of the hydrate slurry in circulation,
The heat density can be continuously measured only by measuring the physical state of the hydrate slurry in the flowing state such as temperature and flow rate, that is, by measuring the process amount. It is extremely effective for measurement and control of hydrate slurry production plant.

The present invention according to claim 2 is characterized in that the aqueous solution is an aqueous solution containing a guest compound which forms a plurality of hydrates having different hydration numbers. . Therefore, even for those in which it is difficult to grasp the type of hydrate in the solid phase of the hydrate slurry, the heat density can be effectively measured, which is particularly effective.

Further, in the present invention according to claim 3, the guest compound is a tetra-n-butylammonium salt, a tetra-iso-amylammonium salt, a tetra-n-butylphosphonium salt or a tri-iso-amylsulfone salt. It is characterized in that it is one kind or two or more kinds selected from the aluminum salts.

These guest compounds can form a hydrate at 0 ° C. or higher, for example, about 12 ° C. in TABA, and can improve the efficiency of energy required for this formation, and can also be a cooling heat source for cooling. In addition, it can be used as both a heat source for snow melting roads, etc., and its characteristics are stable and effective.

Further, the present invention according to claim 4 includes particles of a plurality of types of hydrates, the initial aqueous solution concentration is known, and the ratio of the particles of each type of the hydrate is unknown. A device for measuring the heat density of a hydrate slurry that is
The above-mentioned hydrate slurry is circulated, and the pressure drop element with a known relationship between the ratio of the solid phase in the hydrate slurry and the pressure loss and the pressure drop of the hydrate slurry passing through the above pressure drop element are measured. Pressure loss detection mechanism, a flow rate detection mechanism for measuring the flow rate of the hydrate slurry passing through the pressure loss element, a temperature detection mechanism for measuring the temperature of the hydrate slurry passing through the pressure loss element, and An arithmetic circuit for receiving the signals from the pressure loss detecting mechanism, the flow rate detecting mechanism, and the temperature detecting mechanism and calculating the heat density of the hydrate slurry.

Therefore, the heat density of the hydrate slurry can be easily measured with a simple structure, and each element and mechanism constituting this device is a device conventionally used for measuring the process amount of fluid. The reliability is high, and the reliability of the entire device is high.

The present invention according to claim 5 is characterized in that the pressure loss element is an orifice. Therefore, the pressure drop or SP of this hydrate
F can be measured with high accuracy, and the measurement accuracy of heat density can be increased.

The present invention according to claim 6 is characterized in that the pressure loss element is a piping element. Therefore, the relationship between the pressure loss and the SPF of some piping elements through which the hydrate slurry flows, such as a part of a straight piping, an elbow, a different diameter joint, and other original piping elements, is measured in advance. By using these, they can be used as pressure loss elements, so the structure is simple and
It is not necessary to add a pressure drop element that increases the pressure loss of the hydrate slurry, and the energy required to transport the hydrate slurry can be saved.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A method according to an embodiment of the present invention will be described below with reference to the drawings together with a configuration of an apparatus according to a first embodiment. In this embodiment, a TBAB hydrate slurry is produced, and this hydrate slurry is supplied to the user side, that is, the air conditioning load side. In this case, the guest compound contained in the aqueous solution is only one kind of the above TBAB, but this TBAB is composed of two kinds of water, that is, the first hydrate and the second hydrate having different hydration numbers and latent heat amounts. Produces a Japanese product.

FIG. 1 shows a schematic structure of the hydrate production, heat storage and supply device. Reference numeral 1 in the figure denotes a heat storage tank for storing the hydrate slurry, and the hydrate slurry 2 is stored inside the heat storage tank. Reference numeral 3 in the drawing denotes a cold heat source such as a refrigerator, which produces a low-temperature refrigerant, for example, cold water, and this cold water is supplied to the first manufacturing heat exchanger and the second manufacturing heat exchanger 6 by the cold water pump 4. Is circulated through.

The aqueous solution or hydrate slurry in the heat storage tank 1 is sent to the first and second manufacturing heat exchangers 5 and 6 by the manufacturing pump 7. Then, the production heat exchangers 5 and 6 cool the aqueous solution or the hydrate slurry to produce a hydrate. Then, this hydrate slurry is returned and stored in the heat storage tank 1.

The hydrate slurry stored in the heat storage tank 1 is sent by the transport pump 8 to the air conditioning load 9, for example, the user side for air conditioning, where the cold heat of the hydrate slurry is held. Is used and returned to the heat storage tank 1 again. In addition, in FIG. 1, only one air conditioning load 9 is drawn for simplification of the drawing, but in an actual device,
There are a plurality of air-conditioning loads 9, that is, users.

A heat density measuring device 10 for measuring the heat density of the hydrate slurry is provided in the return pipe from the manufacturing heat exchangers 5 and 6 to the heat storage tank 1, and the hydrate is measured. It is used as a control process amount in a product slurry manufacturing plant. In addition, a heat density measuring device 10 similar to the above is provided in the middle of the piping of the hydrate slurry sent to the air conditioning load 9, and each air conditioning load, that is, the amount of cold heat used by the user is measured.

Next, the structure and operation of the first embodiment of the thermal density measuring apparatus 10 will be described with reference to FIG. 2, and the measuring method of the present invention will be described together with this.
The measuring method of the present invention is not always performed by using the above-mentioned device, and other devices may be used.

Reference numeral 11 in FIG. 2 is a pipe for transporting the hydrate slurry. A pressure loss measuring unit 12 is connected in the middle of the pipe 11, and an orifice 13 is provided in the pressure loss measuring unit 12 as a pressure loss element. The orifice 13 is calibrated by previously measuring the relationship between the SPF of the hydrate slurry, the flow rate and the pressure loss (pressure drop).

A flow rate detecting mechanism 14 for measuring the flow rate of the hydrate slurry and a temperature detecting means for measuring the temperature of the hydrate slurry are provided in the pipe 11, for example, upstream of the pressure loss measuring section 12. A mechanism 15 is provided.

The pressure loss measuring unit 12 is provided with pressure detecting mechanisms 16 and 17 on the upstream side and the downstream side of the orifice 13, respectively, to reduce the pressure drop of the hydrate slurry passing through the orifice 13. It is detected, and these constitute a pressure loss detection mechanism.

The signals from the flow rate detecting mechanism 14, the temperature detecting mechanism 15, and the pressure detecting mechanisms 16 and 17 are
It is sent to the arithmetic circuit 18, and the arithmetic circuit 18 is configured to continuously calculate the heat density of the circulating hydrate slurry online from these signals.

Next, the operation of the apparatus according to the embodiment of the present invention and the measuring method of the present invention will be described together. First, there is a correlation as shown in FIG. 4 between the ratio of the solid phase in the hydrate slurry, that is, SPF, and the viscosity. Therefore, when the hydrate slurry passes through a pressure loss-generating element such as the orifice 13 described above, a pressure loss, that is, a pressure drop occurs. Then, the flow rate of the hydrate slurry is measured by the flow rate detecting mechanism 14 and the pressure loss is measured by the pressure detecting mechanisms 16 and 17 to obtain the viscosity of the hydrate slurry, that is, the SPF.

However, as described above, the TBAB hydrates include hydrates of the types of primary hydrate and secondary hydrate having different latent heat amounts. In this case, as shown in FIG.
The relationship between the temperature of the hydrate slurry and the SPF differs depending on whether the solid phase in the hydrate slurry is the first hydrate or the second hydrate.

Therefore, by measuring the temperature of the hydrate slurry by the temperature detecting mechanism 15, the solid phase component in the hydrate slurry is the first hydrate or the second hydrate. Alternatively, the ratio of these can be calculated.

From the above measurement and calculation results, the latent heat amount and sensible heat amount of the solid phase component of this hydrate slurry and the sensible heat amount of the aqueous solution component can be calculated, and these are summed to obtain the hydrate slurry. The heat density can be calculated.

In the above embodiment, the flow rate of the hydrate slurry is measured by the volume flow rate. The density of this hydrate slurry changes depending on the type of solid phase component, temperature, etc., but these can be measured and calibrated in advance, and can be corrected by the arithmetic circuit 18 described above. it can. Note that FIG. 6 shows the relationship between the density and heat density of the hydrate slurry used for such calibration.

In such a measuring method, it is not necessary to take out a sample of the hydrate slurry, and the heat density of the flowing hydrate slurry is continuously maintained online only by the process amount such as the flow rate, temperature and pressure loss. Can be measured.

The apparatus of this embodiment has a flow rate detecting mechanism 14, a temperature detecting mechanism 15, and pressure detecting mechanisms 16 and 17.
Since it is possible to use conventionally used equipment and does not require any special measuring equipment, the reliability is high and the manufacturing cost is low.

In the device of the above embodiment, the heat density measuring device 10 is provided only in the supply pipe to the air conditioning load 9, but it does not matter whether the air conditioning load 9 or the user side uses cold heat. In an apparatus that constantly circulates the hydrate slurry, if the heat density measuring device as described above is provided in the middle of the return pipe from the air conditioning load 9, the heat density on the supply side and the return side will be increased. From the difference in heat density measured by the measuring device 10 and the flow rate thereof, the amount of cold heat used by the user can be accurately measured.

The device of the present invention is not limited to that of the first embodiment. For example, FIG. 3 shows a thermal density measuring device according to a second embodiment of the present invention. This uses a part of the piping element, for example, the part of the elbow joint 20, as the pressure loss element. Of course, the pressure drop that occurs at the elbow joint 20 and the S of the hydrate slurry
Of course, the relationship with the PF should be measured in advance.

Since the apparatus of such an embodiment uses a part of the piping element as a pressure loss element, it does not require a special member such as an orifice as in the first embodiment, and has a structure. It's easy. Further, it is not necessary to specially provide an element such as an orifice which causes a pressure loss in the middle of the pipe, the pressure loss of the hydrate slurry flowing in the pipe can be reduced, and the power required to transport the hydrate slurry can be reduced. can do.

The piping element used as the pressure loss element is not limited to the elbow joint portion as described above, but may be a reducing joint or other piping element, and a predetermined length portion of a straight pipe may be used. It can be used as a pressure drop element.

The apparatus of the second embodiment has the same configuration as that of the apparatus of the first embodiment except for the points described above, and the portion corresponding to the first embodiment in FIG. Are denoted by the same reference numerals and description thereof will be omitted.

The measuring method and apparatus of the present invention are not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, the case of supplying cold heat for cooling has been described, but when supplying a hydrate slurry for heating, such as a snow melting road in a cold region, a snow melting roof, a constant temperature warehouse for freeze prevention, etc. In this case, the hydrate is formed on the load side and the hydrate is melted on the feed side.

[0044]

As described above, in the measuring method of the present invention, the measuring process is simple, and the water in the flowing state such as the pressure loss, temperature, flow rate, etc. of the flowing hydrate slurry is being measured. The heat density can be measured only by measuring the state of the Japanese slurry, that is, the process amount, which is extremely effective for measuring the amount of cold heat used by the user and controlling the hydrate slurry production plant. , Its effect is great.

Further, the measuring device of the present invention can easily measure the heat density of the hydrate slurry with a simple structure, and each element and mechanism constituting this device can measure the process amount of the fluid. It is a device that has been used in the past, and its reliability is high, and the reliability of the entire device is also high.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an entire cold heat production and supply device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a thermal density measuring device according to a first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a thermal density measuring device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between SPF and viscosity of a hydrate slurry.

FIG. 5 is a graph showing the relationship between SPF and temperature of hydrate slurry for each type of hydrate.

FIG. 6 is a diagram showing the relationship between hydrate density and heat density.

[Explanation of symbols]

1 heat storage tank 2 refrigerator 5,6 Manufacturing heat exchanger 10 Heat density measuring device 13 Orifice 14 Flow rate detection mechanism 15 Temperature detection mechanism 16,17 Pressure detection mechanism 20 Elbow fitting

Continuation of the front page (56) Reference JP-A-11-264806 (JP, A) JP-A-7-98290 (JP, A) JP-A-6-137620 (JP, A) JP-A-5-322669 (JP , A) JP-A-7-167718 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01K 17/06 F24F 5/00 102 F28D 20/02

Claims (6)

(57) [Claims] 1. The heat density of a hydrate slurry containing particles of a plurality of types of hydrates, the initial concentration of the aqueous solution of which is known, and the ratio of the particles of each type of the hydrate is unknown. A method of measuring, wherein the latent heat and sensible heat characteristics of each hydrate of the plurality of hydrates are measured in advance, and the sensible heat characteristics of the aqueous solution are measured in advance. And a step of measuring beforehand the relationship between the ratio of the solid phase in the slurry of the hydrate and the temperature of the hydrate slurry for each of the plurality of hydrates, and the above hydrate A process of preparing a pressure loss element in which the relationship between the solid phase ratio of the hydrate slurry and the flow rate and the pressure loss when the slurry is circulated is prepared in advance, and the above hydrate slurry is passed through the pressure loss element through the pressure loss element. Circulate, measure the flow rate, pressure loss, and temperature, and From the hydrate flow rate, pressure drop, temperature, and known values obtained in the above process, from the total amount of solid phase in the hydrate slurry, and in the solid phase A method for measuring the heat density of a hydrate slurry, which comprises calculating the ratio of each hydrate type and calculating the heat density of the hydrate slurry from the calculation result. 2. The method for measuring the heat density of a hydrate slurry according to claim 1, wherein the aqueous solution is an aqueous solution containing a guest compound that forms a plurality of hydrates having different hydration numbers. . 3. The guest compound is tetra-n-butylammonium salt, tetra-iso-amylammonium salt, tetra-n-butylphosphonium salt, tri-iso.
-One or two selected from amyl sulfonium salts
The method for measuring the heat density of a hydrate slurry according to claim 2, wherein the method is at least one kind. 4. The heat density of a hydrate slurry containing particles of a plurality of types of hydrates, the initial concentration of the aqueous solution of which is known, and the ratio of the particles of each type of the hydrate is unknown. A device for measuring, wherein the hydrate slurry is circulated, and a pressure loss element having a known relationship between the ratio of the solid phase in the hydrate slurry and the pressure loss, and hydration that has passed through the pressure loss element. Pressure drop detection mechanism for measuring the pressure drop of the product slurry, flow rate detection mechanism for measuring the flow rate of the hydrate slurry passing through the pressure drop element, and temperature of the hydrate slurry passing through the pressure drop element Hydration characterized by comprising a temperature detecting mechanism and an arithmetic circuit for receiving the signals from the pressure loss detecting mechanism, the flow rate detecting mechanism, and the temperature detecting mechanism to calculate the heat density of the hydrate slurry. Thermal density measuring device for material slurry. 5. The heat density measuring device for hydrate slurry according to claim 4, wherein the pressure drop element is an orifice. 6. The heat density measuring device for a hydrate slurry according to claim 4, wherein the pressure drop element is a piping element.