JPH01263473A - Highly efficient operation method of ice bank and its device - Google Patents

Abstract

PURPOSE:To provide a utilization of ice bank with a high efficiency by a method wherein a thickness of ice adhered to a surface of a thermal transmitting pipe of a target item to be iced is made to have a uniform thickness at each of portions of the surface and an advancing direction of of coolant flowing within the thermal transmitting pipe is converted into an opposing direction and advanced. CONSTITUTION:A coolant pipe passage capable of performing an alternative operation of a top feed in which a coolant liquid is fed and a bottom feed is provided. At the beginning of a thermal accumulating operation, a normal icing is got mainly at an outer surface of a lower stage of a thermal transmitting pipe 2 through the bottom feeding system and an intermediate water level 21 is detected by a water level sensor 19, thereafter it is automatically changed over to the top feeding system, thereby a normal icing is got mainly at an outer surface of an upper stage of the thermal transmitting pipe 2 through an automatic changing- over to the top-feeding system. In this way, a uniform thick icing is got over each of the stages of the thermal transmitting pipe 2, thereafter an intrinsic normal high water level 20 is detected by a water level sensor 19 and then a thermal accumulating operation is completed. At this time, at the beginning of operation, it is changed to the top feeding system in opposition to the former operation and it is also possible to change over it to the bottom feeding system with the intermediate water level 21.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention is directed to freezing water or an aqueous solution and utilizing latent heat and heat sensitivity to use it as a cold heat source for air conditioning. To provide a method and apparatus for making the thickness of ice that reaches the surface nearly uniform in each part by timely changing the traveling direction of the refrigerant flowing in the heat transfer tube in the opposite direction and achieving highly efficient use of the ice bank. It is something.

``Prior Art'' A conventionally known ice heat storage means consists of arranging multiple rows of multi-stage horizontal hairpin coiled heat transfer tubes in which the refrigerant flows continuously from one side to the other inside an insulating tank. The refrigerant liquid is supplied from the expansion valve at the end using a dessl-'J computer, and while flowing horizontally and upward inside the heat transfer tube, the water outside the heat transfer tube or the refrigerant liquid that has absorbed heat from the aqueous solution is successively vaporized. Either a dry refrigerant feed method, i.e., a bottom feed method, in which the refrigerant is sucked in as a gas into the compressor suction side through headers connected to the ends of the heat transfer tubes in the uppermost stage, or a distributor from an expansion valve to the ends of each of the heat transfer tubes in the uppermost two stages. The refrigerant liquid is supplied using a heat exchanger tube, and while flowing horizontally and downward inside the heat exchanger tube, the refrigerant liquid that absorbs heat from the water or aqueous solution outside the heat exchanger tube is successively vaporized, and the header connects the ends of the lowest heat exchanger tubes. This is a so-called top feed method, which is a dry refrigerant feed method in which the refrigerant is sucked into the suction side of the compressor as a gas.

``Problems to be Solved by the Invention'' In the above-mentioned dry bottom feed method of conventionally used ice heat storage devices, ice of a normal thickness is formed on the outer surface of the lower stage of the heat transfer tube, but ice of a normal thickness is formed on the outer surface of the upper stage. The ice is formed in such a state that the thickness of the ice decreases to the extent that it reaches
If an attempt is made to obtain an excessive amount of water in order to improve the ice packing factor, an abnormally thick layer of ice will form in the lower stage, blocking the space between the heat transfer tubes arranged in multiple rows in the lower stage. Since it blocks the air that is constantly blown into the heat transfer tubes from the air blow tube placed below the heat tube group, it promotes the formation of ice between the heat transfer tubes arranged in multiple rows in the lower stages, making it evenly thick on each stage of the heat transfer tubes. unable to form ice. In addition, in the dry top feed method described above, a phenomenon opposite to that of the bottom feed method occurs, and the lower ice is formed with a reduced thickness. When trying to obtain an excessive amount of ice in order to improve P and F, abnormally thick ice is formed in the upper stage, and the ice formed between the heat transfer tubes arranged in multiple rows in the lower stage is cold, causing a phenomenon that occurs. The air that is constantly blown into the heat transfer tubes from the air blow tube placed at the bottom of the heat transfer tube group accumulates between the heat transfer tube groups, further promoting ice formation in this area, resulting in the formation of abnormally thick ice and an abnormal rise in water level. As a result, an abnormal situation occurs in which the refrigerant liquid supply is stopped and the heat storage operation is stopped before the predetermined water level signal indicating that the water level has risen and the freezing is completed is reached, resulting in the formation of evenly thick ice on each stage of the heat transfer tubes. It is extremely difficult to improve rivers, P, and F.

In addition, in order to utilize the cold energy of this freezing, a pump is used to guide cold water from the insulation tank to the heat exchanger, heat exchanged with hot water from another system, and the cold water is returned to the insulation tank again in a cold heat radiation operation. Since ice on the outer surface of the heat transfer tubes arranged in multiple stages is evenly melted by blow air, the rated cooling and heat dissipation capacity can be expected at the initial stage of cooling and heat dissipation operation. In this case, the thin ice formed on the upper stage heat transfer tube melts, exposing the heat transfer tube surface and reducing the area of formed water, which causes the cooling and heat dissipation capacity to drop below the rated value in a short period of time. cannot maintain the performance of
In addition, when the cooling heat radiation load is small, in the case of the top feed mentioned above, in the case of the bottom foot of the upper stage, the thick ice formed on each of the lower stage heat transfer tubes melts from the surface, but remains as residual water. Since the cooling heat dissipation operation ends in this state, when the heat storage operation is started next, thick ice will be newly formed in the residual water area, and the ice will form next to the ice in the upper or lower stage of the heat transfer tubes arranged in multiple stages and rows. There was a drawback that the air was connected and inhibited the rise of air blow. The situation is as shown in Figure 4, where A is the normal water level, B is the lower stage heat exchanger tube, B is the lower stage heat exchanger tube, G is the abnormally high water level, and O is the state where ice cannot form evenly on the top and bottom. , that is, in the case of top feed, the lower part has thin ice, 25 is the air blow pipe,
26 is blow air, 27 is water, 36 is a normal frozen portion, and 37 is a state in which normal ice cannot be formed in the lower heat exchanger tube in the case of top feed, that is, abnormally thin ice is formed. 38 indicates a state in which an abnormally thick frozen portion connects with adjacent frozen ice and obstructs the air blow from rising.

"Means for Solving the Problems" The present invention has been made to solve the above-mentioned problems, and the means will be explained using examples and corresponding figures.

As shown in Fig. 1, the hairpin coiled heat exchanger tubes 2 through which the refrigerant flows are arranged in multiple rows in continuous multistage horizontal tubes in the heat insulating tank O, and the ends of the lowest stage heat exchanger tubes are connected to the lower stage and to the dar 3, respectively. , the ends of the uppermost heat exchanger tubes are similarly connected to the upper stage with lugs, and the uppermost stage heat transfer tubes are connected in multiple rows from the expansion valve 6 through the three-way automatic liquid supply valve 7 and the distributor 8 for l. The refrigerant liquid is distributed through the upper header 4 into the end of the heat exchanger tube, and the refrigerant liquid absorbs heat from the water or aqueous solution outside the heat exchanger tube, forms ice on the outer surface of the heat exchanger tube, and then passes through the lower stage header 4. The liquid flows from the end of the lowest heat transfer tube through the lower header 3, from the L/tub feed gas return pipe 11, through the return gas three-way automatic valve 10, to the refrigerant suction pipe 15, and from the expansion valve 6 to the three-way liquid supply pipe. The refrigerant liquid is distributed from the bottom feed distributor 9 via the valve 7 to the ends of the lower heat transfer tubes arranged in multiple rows Q through the lower header 3, and the refrigerant liquid is distributed to the water outside the heat transfer tubes. Alternatively, heat is removed from the aqueous solution, ice is formed on the outer surface of the heat exchanger tube, and then the water flows to the upper stage, from the end of the uppermost heat exchanger tube, through the upper header 4, and from the bottom feed gas return pipe 12 to the three-way automatic valve 10 for return gas. The water level of the heat insulation tank 0 at the initial stage of heat storage operation is at the low water level 22 by providing a so-called 1 hemp foot pipe and a bottom feed method for supplying the refrigerant liquid. is automatically detected by the water level detector 19, and the liquid supply three-way automatic valve 7 and the return gas three-way automatic valve 1 are automatically detected.
0 is automatically switched to the bottom feed method, and the refrigerant liquid is passed through the bottom feed distributor 9 to the heat transfer tube 2.
The water level detector 19 detects that the water level in the insulation tank 0 has risen due to freezing on the outer surface of the heat exchanger tubes 2 and has reached the intermediate water level 21.
or automatically switches the liquid supply three-way automatic valve 7 and the return gas three-way automatic valve 1o to top feed depending on the ice thickness or time difference, and supplies the refrigerant liquid to the heat exchanger tubes via the l/tube feed distributor 8. When the water level of the water or aqueous solution 27 in the insulation tank O reaches the high water level 20, the water level detector 19 automatically stops the compressor 16, terminates the heat storage operation, and turns on the circulation pump and heat exchanger (both (not shown) to perform cooling and heat dissipation operation. During the heat storage operation, the blower 24 always sends the air from the upper part of the heat insulating tank O from the air suction pipe 23 to the air blow pipe 25, and the blow air 26 is blown into the heat transfer tube group 5 in the direction of the number of rows of heat transfer tubes 2. Blow air forms a rising cold water layer to prevent ice from joining, and during cooling/heat dissipation operation, the blow air = 26 evenly removes the ice formed on the heat exchanger tubes 2. It is something to be understood.

"action" Next, the operation will be explained using FIGS. 1 and 2.

The temperature sensor 28 of the expansion valve 6 shown in FIG. 1 is attached to the pipe on the outlet side of the expansion valve 6, and constantly senses the temperature of this part. The jL degree sensor 9 is attached to the refrigerant suction pipe 15 closest to the return gas three-way automatic valve 10, and constantly senses the temperature of this part, and the expansion valve 6 is electrically connected to the expansion valve controller 13 and the s1 temperature sensor 28. and s2 temperature sensor, and when the necessary superheat degree tsh is set in the superheat degree setting unit 14 attached to the expansion valve controller 13, the temperature L1 of the S temperature sensor 28 and the temperature t2 of the s2 temperature sensor 29 are always set. The refrigerant liquid is supplied to the heat transfer tubes 2 by adjusting the valve opening degree of the expansion valve 6 by 5JjJ so that tSh=tz L, but the superheat degree setting unit 14 sets tSh=o°C.
When this is set, the refrigerant liquid supplied from the expansion valve 6 corrects the excessive liquid supply phenomenon, and the refrigerant liquid that has not been completely vaporized in the heat transfer tube 2 passes through the refrigerant suction pipe 15 and flows into the compressor 16, and the operation is stopped. This superheating degree tsh in the dry refrigerant foot method is absolutely necessary for operating the main heat storage device, and usually tsh-
6 to 12°C, so if the refrigerant liquid is supplied by either the tube feed method or the bottom feed method, the phenomenon A or B, which is not shown in Fig. 2, will occur immediately. Either normal ice 36 is formed on the outer surface of the heat exchanger tube 2 close to the liquid supply side, or abnormally thin ice 37 is formed on the outer surface of the heat exchanger tube 2 far from the liquid supply side. Furthermore, if the top foot system is operated for a long period of time, phenomenon C will occur, and abnormally thick ice 38 will form on the upper part of the heat transfer tube 2, creating an air pocket 39 and causing the water level of the water 27 to rise to the high water level 20. As shown in Figure 4, where the ice has formed normally, the apparent high water level is 20, and the operation is stopped due to the action of the water level detector 19, but this is due to the refrigerant liquid supply method. Since a refrigerant pipe line is installed that can perform the 1-bottom feed and bottom feed methods alternately, normal ice formation is mainly formed on the outer surface of the lower stage of the heat transfer tube 2 by the bottom feed method in the early stage of heat storage operation, and After the water level 21 is detected by the water level detector 1i, the water level detector 1i automatically switches to the top foot method to obtain normal ice formation mainly on the outer surface of the lower stage of the heat exchanger tubes 2, and to form ice that is uniform and thick over each stage of the heat exchanger tubes 2. After freezing, the water level detector 19 detects the originally normal high water level 20 and ends the heat storage operation, or conversely, the top feed method is used at the beginning of the operation and the middle water level 21 is used to stop the heat storage operation. It is also possible to switch to the state D in FIG. 2 without changing the effect in either method.

``Example'' Reference will now be made in detail to the accompanying drawings showing an example of implementing the present invention. 0 is an insulation tank, 1 is a lid of the insulation tank provided on the upper part, 2 is a heat exchanger tube provided in multiple horizontal stages, and the heat exchanger tubes 2 arranged in multiple rows are connected to the lower header at the end of the lowest stage heat exchanger tube, respectively. The distribution pipes 9' of the bottom feed distributor 9 pass through the lower header 3 and are inserted into the ends of the lowermost heat exchanger tubes, and the upper header 4 is inserted at the end of the uppermost heat exchanger tube.
The heat exchanger tubes 2 arranged in multiple rows are connected to each other, and the distribution pipe 8' of the top feed distributor 8 is inserted into each of the uppermost heat exchanger tubes through the two-stage header 4, and The top-feed F gas return pipe 11 and the bottom-feed gas return pipe 12 are connected to the three-way automatic valve 1.04 for return gas from the header 3 and upper header 4, respectively, and the refrigerant suction pipe is connected from the three-way automatic valve 10 for return gas. 15 is connected to the compressor 16, a discharge pipe is connected from the compressor 16 to the condenser/liquid receiver 17, and the condenser/liquid receiver 17 is connected to the expansion valve 6 by a refrigerant high pressure liquid pipe 18. A pipe line is formed from the expansion valve 6 through the liquid supply three-way automatic valve 7 to the bottom foot distributor 1-refutor 9 and the top foot distributor 8, and the compressor 16 is connected to the compressor 16.
The refrigerant scum is compressed and the high-pressure liquefied refrigerant liquid is stored in the condenser/liquid receiver 17, and the liquid is supplied from the expansion valve 6 to the three-way automatic valve 7.
, passes through the bottom foot distributor 9, the distribution pipe 9', flows upward from the bottom heat transfer tube end through the heat transfer tube 2, passes through the upper header 4, the bottom foot death return pipe 12, and returns gas to the three-way automatic The liquid flows downward from the end of the uppermost heat transfer tube through the heat transfer tube 2 through the pipe line leading to the valve 10, the three-way automatic valve 7, the top foot distributor 8, the distribution pipe 8', and the lower header 3 to the top. By switching the pipe line leading to the return gas three-way automatic valve 10 via the foot gas return pipe 11, that is, the liquid supply three-way automatic valve 7 and the return gas three-way automatic valve 10, respectively, the refrigerant liquid can be fed into the bottom feed method or the top feed method. The heat transfer tubes 2 are immersed in the water or aqueous solution 27 in the heat insulating tank 0 by configuring a pipe line that alternately switches and supplies liquid, and the S1 temperature sensor 28 of the expansion valve 6 is connected to the outlet side pipe of the expansion valve 6. and attach the S2 temperature sensor 29 to the return gas three-way automatic valve 10 of the refrigerant suction pipe 15.
Attach it similarly to the closest one, and s1 temperature sensor 28
, s2 The temperature from the temperature sensor 29 is converted into an electric signal and given to the expansion valve controller 13, and the superheat degree tsh set by the superheat degree setting section 14 is s, /IA degree sensor 2
The values t0 and t2 of the temperature sensor 8 and s2 temperature sensor 29 are calculated in the expansion valve controller 13 so that the value becomes tsh-tz t+, and the opening degree of the expansion valve 6 can be controlled. An air blowing tube 25 is provided at the lower part of the heat tube group 5, and air is constantly blown to the heat transfer tube group 5 by the blower 24 through the air suction tube 23 led from the air layer (space) 30 during the heat storage operation and the cold heat dissipation operation. , the water level detector 1 indicates that the insulation tank O is at a low water level 22.
9, and the top foot method (or phone 1~
Initial heat storage operation is started using the water level detector 19 (Mufito method), and when the medium water level is detected by the water level detector 19, the operation is switched to the Bot I Mufeed method (or top foot method), and when the high water level is 20
The water level detector 19 automatically detects this and stops the operation of the compressor 6.

``Effects of the Invention'' As shown in ``Operation'' above, the three-way automatic valve for liquid supply 7 and the three-way automatic valve for return gas 10 are switched to operate the bottom feed system (or 1 to
F method) The I and Tubufi F method (or Hosotomphy F method) are performed alternately at a medium water level, so that the refrigerant liquid can be supplied to the heat exchanger tubes 2 uniformly to the upper and lower stages on the outer surface of the heat exchanger tubes 2. A thick normal ice formation 36 is obtained and the second
Since the state shown in the figure will occur, an abnormal G as shown in C of the same figure will occur.
Since the air pocket 39 is not formed due to the thick ice 38, the abnormally high water level 20 does not occur, it is possible to avoid the phenomenon where the water level detector 19 malfunctions, and the cooling and heat dissipation load is small. In this case, the ice melts uniformly across each row and stage outside the heat exchanger tubes 2, resulting in uniform residual water, so even if the cooling heat dissipation operation is ended and the heat storage operation is subsequently started, no part of the outer surface of the heat exchanger tubes 2 will melt. Normal, thick, uniform ice is again obtained in this area.

In cold heat dissipation operation, a capacity higher than the rated value can be expected, and since the area of water formed can be sustained, the cold heat dissipation capacity can be maintained for a long time, stable performance can be obtained, and high efficiency can be achieved.

[Brief explanation of the drawing]

The accompanying drawings show an example of the present invention, and FIG. 1 is a diagram showing a refrigerant pipe system, an expansion valve, temperature sensors, and an electrical system for an expansion valve controller in a cross section of a heat-insulating tank. FIG. 2 is a new view showing the state of ice formed on the outer surface of the heat transfer tube inside the heat insulating tank. FIG. 3 is a partially sectional side view of the upper header and a portion of the lower header. FIG. 4 is a cross-sectional view showing the state of ice formed on the outer surface of the heat exchanger tube inside the heat-insulating tank of the conventional product. 〇-insulation tank, 1-insulation lid, 2-heat transfer tube, 3-lower header, 4-upper header, 5-heat transfer tube group, 6-expansion valve, 7
-3-way automatic liquid supply valve, 8-Distributor for top feed, 8'-Distributor distribution piping for top feed, 9-Distributor for bottom/71-m feet, 9
' - Distributor distribution pipe for bottom feed, 1
0- Three-way automatic valve for return gas, 11- Gas return pipe for tomp feed, 12- Gas return pipe for bottom feed, 1
3-controller for expansion valve, 14-superheat degree setting section, 15
- Refrigerant suction pipe, 16- Compressor, 17- Condensing liquid receiver, 1
8-Refrigerant high pressure liquid pipe, 19-Water level detector, 20-High water level (
Heat storage operation completed), 21-Medium water level (bottom feed method/7p feed switching), 22-Low water level (heat storage operation started), 23-Air suction pipe, 24-Blower, 25-Air blow pipe, 26-Blow air, 27-water or aqueous solution, 28-s temperature sensor, 29--s 2 temperature sensor, 30-air layer (space), 31--uppermost heat exchanger tube end, 32-lowermost heat exchanger tube end, 33-Electric wire, 34
- power supply, 35- air layer (space), 36- normal freezing,
37-Unusually thin ice, 38-Unusually thick ice, 39-
Air pocket, A - Freezing condition due to bottom feed method, B-1 - Freezing condition due to tube feed method, C
-1-A state in which an abnormally thick ice film is formed on the heat exchanger tube using the tube feed method, I) - A state in which a uniform thick normal ice is formed using both the tube foot method and the bottom feed method, A is normal. Water level, E upper heat exchanger tube, O lower stage heat exchanger tube, Knee abnormally high water level, condition where ice cannot form evenly above and below O.

Claims (1)

[Claims] 1. A method for highly efficient operation of an ice bank, characterized in that the flow direction of the refrigerant in the ice bank heat exchanger tube is reversed midway through the flow. 2. A high-efficiency operating device for an ice bank, characterized in that a switching valve is provided at both ends of a heat transfer tube for an ice bank, so that the inflow direction and the outflow direction of the refrigerant can be arbitrarily switched. 3. An ice bank characterized in that a switching valve is provided at both ends of the heat transfer tube for the ice bank, so that the inflow direction and the outflow direction of the refrigerant can be changed arbitrarily depending on changes in the water level in the insulation tank, ice thickness, or time difference. High efficiency actuation device. 4. A continuous multi-stage horizontal hairpin coiled heat exchanger tube is provided inside the heat insulating tank so that the refrigerant flows inside the tube, and a conduit is formed that communicates from the end of the lowest heat exchanger tube to the end of the uppermost heat exchanger tube, A heat transfer tube provided with an upper header and a lower header, each of which connects the uppermost and lowermost pipe ends, is housed in the heat insulating tank so as to be submerged in water or an aqueous solution, and air is blown out at the bottom of the heat insulating tank. In an ice bank system with holes, there is a distributor that connects from the expansion valve to the end of the lowest heat transfer tube through a three-way automatic valve for liquid supply, and a refrigerant gas suction that goes from the lower header to the gas suction side of the compressor through a three-way automatic valve. In addition to installing a pipe, the separate distributor connects from the expansion valve to the liquid supply three-way valve at the end of the uppermost heat transfer tube, and connects from the upper header to the gas suction side of the compressor through the return three-way automatic valve. Separate refrigerant gas suction pipes are arranged in parallel to form separate pipes, and depending on the water level change in the insulation tank, ice thickness, or time difference, each pipe is connected from the expansion valve to the liquid supply three-way automatic valve, and then from the distributor to the lowest heat transfer pipe. A high efficiency operating device for an ice bank, characterized in that when refrigerant is supplied, refrigerant gas can be alternately returned from the uppermost heat transfer tube to the upper header and the return three-way automatic valve. 5. Depending on the water level change in the insulation tank, ice thickness, or time difference, refrigerant is supplied from the expansion valve to the top heat transfer tube from a separate distributor via a three-way automatic liquid supply valve, and from the bottom heat transfer tube to the lower header. 5. The high-efficiency operating device for an ice bank according to claim 4, wherein the refrigerant gas can be alternately returned to the three-way return valve and the return three-way automatic valve. 6. A continuous multi-stage horizontal hairpin coiled heat exchanger tube in which refrigerant flows inside the insulation tank, an upper header and a lower header connecting the tube ends of the lowest and top stages, and an expansion tube at the end of the lowest stage heat exchanger tube. A bottom distributor that supplies liquid from the valve via a three-way automatic valve, a bottom refrigerant gas suction pipe that returns from the lower header to the gas suction side of the compressor via a three-way automatic valve, and an expansion valve that supplies liquid to the end of the top heat transfer tube. The pipes are arranged in multiple rows, each consisting of a top distributor that passes through a liquid three-way automatic valve, and a top refrigerant gas suction pipe that runs from the upper header through a return three-way automatic valve to the gas suction side of the compressor. The high-efficiency operating device for an ice bank according to claim 4, characterized in that: