JP2015218932A - Heat insulation structure of hot water storage tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat insulation structure of a hot water storage tank in which frequency of reheating operations is reduced.SOLUTION: A heat insulation structure of a hot water storage tank includes: a plurality of hot water storage temperature sensors 21a-21e installed in a height direction on a peripheral wall of a hot water storage tank 7 and for detecting temperature of stored hot water; and control means 22 which, when the hot water storage temperature detected by the hot water storage temperature sensor 21b is detected to be equal to or less than first predetermined temperature T1 which requires a reheating operation, starts a reheating operation by heating means 2, and also, when the hot water storage temperature sensor 21d provided at a position lower than the hot water storage temperature sensor 21b detects equal to or greater than second predetermined temperature T2 higher than the first predetermined temperature T1 for terminating the reheating operation, the control means performs control for terminating the reheating operation by the heating means 2. From a top part of the hot water storage tank 7 to an upper outer periphery of the hot water storage tank 7 including the hot water storage temperature sensor 21b for starting the reheating operation is covered with a vacuum heat insulation material 23, and from a bottom part of the hot water storage tank 7 to a lower outer periphery of the hot water storage tank 7 including the hot water storage temperature sensor 21d for terminating the reheating operation is covered with a foam heat insulation material 24.

Description

  The present invention relates to a heat insulation structure of a hot water storage tank provided with a vacuum heat insulating material for heat insulation and heat insulation of the hot water storage tank of a heat pump type hot water heater.

Conventionally, in this kind of thing, a foamed heat insulating material divided into three parts, upper and middle, is connected between the hot water storage tank and the outer case with an uneven fitting, and the hot water in the hot water storage tank is connected with the heat insulating material. It was well insulated for a long time. (See Patent Document 1.)
Also, some vacuum insulation materials that are thin and have a high heat insulation effect are used so as to cover the central cylindrical portion of the hot water storage tank. (See Patent Document 2.)

Japanese Patent No. 3561239 Japanese Patent No. 4254902

  By the way, in this conventional one, no consideration is given to the reheating operation using expensive electricity in the daytime, that is, by preventing the temperature drop of the hot water temperature in the central part of the hot water storage tank that starts the reheating operation. In addition, the number of times of boiling is reduced to reduce power consumption and improve the efficiency, or the hot water storage temperature sensor for detecting the hot water temperature in the hot water storage tank after the completion of boiling operation is provided. Insulation with a vacuum heat insulating material has a problem that the entire instrument becomes expensive.

  In order to solve the above-mentioned problems, the present invention has a configuration in which, in particular, a hot water storage tank for storing hot water heated by a heating means, and a plurality of hot water storage tanks installed in the height direction on the peripheral wall of the hot water storage tank for detecting the temperature of the hot water storage. When the hot water storage temperature sensor detects that the hot water temperature detected by the hot water storage temperature sensor is below the first predetermined temperature that requires boiling operation, the heating means starts heating operation and is provided at a position lower than the hot water temperature sensor. And a control means for controlling the end of the reheating operation by the heating means when the hot water storage temperature sensor detects a second predetermined temperature higher than the first predetermined temperature at which the reheating operation is terminated. A hot water storage tank upper periphery including a hot water temperature sensor for starting the boiling operation from the top of the hot water storage tank is covered with a vacuum heat insulating material, and the boiling water from the bottom of the hot water storage tank The hot water storage tank lower periphery including hot water storage temperature sensor to terminate the operation increase is covered with an foam insulation.

  As described above, according to the present invention, including the hot water storage temperature sensor for detecting whether the hot water temperature in the central portion of the hot water storage tank, which is a condition for starting the reheating operation, is equal to or lower than the first predetermined temperature, Including a hot water storage temperature sensor that covers up to the central portion with a vacuum heat insulating material and detects whether the hot water temperature in the lower portion of the hot water storage tank, which is a condition for completion of the heating operation, is higher than a second predetermined temperature higher than the first predetermined temperature; By covering the bottom and bottom of the hot water storage tank with normal foam insulation, heat dissipation from the hot water from the center to the top of the hot water tank is suppressed, and the hot water temperature does not drop, reducing the frequency of operation, There is no wasteful power consumption, it is economical, and the hot water storage temperature sensor that detects the end temperature of boiling-up operation is insulated with normal foam insulation, so it does not require good insulation only by detecting the end temperature Expensive in part Without the use of empty insulation material is one which can be provided at low cost as a whole.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the hot water storage type water heater which shows one Embodiment with which the heat insulation structure of this invention is given. Explanatory drawing which shows the heat insulation structure of a hot water storage tank. Sectional drawing of the principal part.

Next, an embodiment of the present invention will be described with reference to the drawings.
1 is an exterior case constituting a hot water storage tank unit, 2 is a heating means comprising a heat pump unit, 3 is a hot water tap, 4 is a remote controller, 5 is a bathtub, and 6 is a power source.

  In the exterior case 1, a hot water storage tank 7 for storing hot water, a hot water pipe 8 connected to the upper part of the hot water storage tank 7, a water supply pipe 9 connected to the lower part of the hot water storage tank 7, and the hot water pipe 8 A mixing valve 11 for mixing high-temperature water and low-temperature water from the bypass pipe 10 branched from the water supply pipe 9, a hot water supply pipe 12 connected downstream of the mixing valve 11, and a hot water supply temperature sensor provided in the hot water supply pipe 12 13, a hot water flow rate sensor 14 provided in the hot water supply pipe 11, a hot water temperature sensor 15 provided in the water supply pipe 9, a hot water pipe 16 branched from the hot water pipe 12 and connected to the bathtub 5, and this hot water filling An overpressure relief that releases the overpressure of the hot water storage tank 7 that is branched from the hot water pipe 8 and connected to the hot water flow rate sensor 18 that integrates the flow rate flowing through the hot water pipe 16. Provided in the valve 19 and the water supply pipe 9 A pressure reducing valve 20 for reducing the water supply pressure is provided.

  Five hot water storage temperature sensors 21a to 21e that detect the hot water storage temperature in the hot water storage tank 7 at predetermined intervals in the height direction on the peripheral wall of the hot water storage tank 7 are provided in order from the top, and the second from the top. The hot water storage temperature sensor 21b detects the temperature below the first predetermined temperature T1, which is the boiling start temperature, 40 ° C. or less, and causes the control means 22 to perform the boiling increase operation by the heating means 2, and the second hot water temperature sensor from the bottom. The control means 22 finishes the boiling operation by detecting a temperature equal to or higher than the second predetermined temperature T2 higher than the first predetermined temperature T1, which is the boiling end temperature 21d.

  23 is a vacuum heat insulating material covering the outer periphery of the hot water storage tank 7 including the hot water storage temperature sensor 21b for starting the heating operation from the top of the hot water storage tank 7, and heat dissipation of the hot water storage from the center to the top of the hot water storage tank 7. In this way, the hot water storage temperature is not lowered, so that the frequency of the boiling operation is increased and unnecessary power consumption is eliminated.

Reference numeral 24 denotes a normal foam heat insulating material having a lower heat insulating capacity than the vacuum heat insulating material 23 covering the outer periphery of the hot water storage tank 7 including the hot water storage temperature sensor 21d for ending the heating operation from the bottom of the hot water storage tank 7, and only detects the end temperature. Therefore, it is possible to provide an inexpensive vacuum heat insulating material 23 as a whole without using an expensive vacuum heat insulating material 23 in a portion that does not require good heat insulation, and the joint between the vacuum heat insulating material 23 and the foam heat insulating material 24 is foamed. A notch 25 is formed inside the upper end of the heat insulating material 24 and the lower end of the vacuum heat insulating material 23 is inserted into the notch 25 so that the vacuum heat insulating material 23 and the foamed heat insulating material 24 overlap each other. Therefore, heat radiation can be surely prevented.
Reference numeral 26 denotes a heating circulation circuit comprising a heat pump forward pipe 27 and a heat pump return pipe 28 for circulating hot water by connecting the hot water storage tank 7 and the heating means 2.

  The heating means 2 includes a compressor 29 for compressing carbon dioxide refrigerant, a refrigerant water heat exchanger 30 as a condenser, a decompressor 31, a heat pump circuit 33 including an air heat exchanger 32 as an evaporator, air A blower 34 for blowing air to the heat exchanger 32, a variable capacity circulation pump 35 provided in the middle of the heating circulation circuit 26, and a refrigerant water heat exchanger 30 provided on the refrigerant water heat exchanger 30 inlet side of the heating circulation circuit 26. A heat exchange inlet temperature sensor 36 that detects the temperature of hot water flowing into the water 30 and a refrigerant water heat exchanger 30 outlet side of the heating circuit 26, and detects the temperature of hot water flowing out of the refrigerant water heat exchanger 30. The heat exchanger outlet temperature sensor 37 and a heating control unit 38 constituted by a microcomputer for controlling the heating means 2 are provided.

  Here, the power source 6 is an electric lamp according to the time zone, and is set at a low price for power charges at night (from 23:00 to 7:00 here). It heats up the amount of hot water needed for the day and uses it in the daytime (from 7:00 to 23:00) with this hourly light. When the remaining amount of hot water decreases, additional boiling Increased operation is performed. The power source 6 is connected to the control means 22, and power is supplied from the control means 22 to the remote controller 4 and the heating control unit 38 by superimposing communication signals in a wired manner.

  When the night time zone is reached, the control means 22 calculates the amount of stored hot water necessary for the next day, and instructs the heating control unit 38 to boil up the target hot water volume by the end of the night time zone. 33 is operated, and the circulation pump 35 of the heating circulation circuit 26 is started to be driven. The hot water taken out from the lower part of the hot water storage tank 7 by driving the circulation pump 35 flows into the refrigerant water heat exchanger 30 of the heating means 2 through the heat pump forward pipe 27 and is heated, and is heated through the heat pump return pipe 28. The hot water is stored by returning to the top of the hot water.

  Furthermore, when the hot water storage temperature sensor 21e provided at the lowermost part of the peripheral wall of the hot water storage tank 7 detects that hot water of a predetermined temperature has been stored, or when the heat exchange inlet temperature sensor 36 detects a predetermined temperature or higher, The control means 22 instructs the heating control unit 38 to stop the heating operation, the heat pump circuit 33 and the circulation pump 35 are stopped, and the hot water storage operation is ended by the end of the night time zone.

  The remote controller 4 includes a temperature setting switch 39 for setting a hot water supply setting temperature, a hot water filling switch 40 for instructing hot water filling to the bathtub 5, a hot water filling amount setting switch 41 for setting the hot water filling amount, and a remaining hot water supply available An operation unit 43 having a remaining time display switch 42 for displaying time, a display unit 44 composed of a liquid crystal screen, and a microcomputer for controlling the operation unit 43 and the display unit 44 and communicating with the control means 22 The remote control unit 45 is configured, and during normal operation, the hot water supply set temperature and time information set by the operation unit 43 and the remaining hot water storage amount detected by the hot water storage temperature sensors 21a to 21e are displayed on the display unit 44. It is what is done.

  Next, when the hot-water tap 3 is opened, the hot water in the upper portion of the hot water storage tank 7 is pushed out to the hot water discharge pipe 8 by the supply water pressure from the water supply pipe 9, and the low temperature of the bypass pipe 10 is controlled by the mixing valve 11 controlled by the control means 22. Water and hot water temperature sensor 13 are mixed so that the temperature detected by hot water supply temperature set by operation unit 43 of remote controller 4 is mixed and hot water is supplied through hot water supply pipe 12.

  If the amount of hot water used is larger than usual and the hot water storage temperature sensor 21b detects the first predetermined temperature T1 or less during the daytime electric power hours, the boiling operation is started via the control means 22. Since the top of the hot water storage tank 7 including the hot water temperature sensor 21b is covered with the vacuum heat insulating material 23, the heat insulation effect is great and the heat radiation is suppressed and the high temperature state is maintained for a long time. If the frequency is reduced and wasteful power consumption can be suppressed, and if a reheating operation is started, the second hot water storage temperature sensor 21d from the bottom of the hot water storage tank 7 detects the second predetermined temperature or higher. The boiling operation is terminated, but the bottom to bottom of the hot water storage tank 7 including the hot water storage temperature sensor 21d is covered with a normal foam heat insulating material 24 having a heat insulating capacity lower than that of the vacuum heat insulating material 23. Because, without the use of expensive vacuum heat insulating material 23 at a portion which does not require good thermal insulation only in the detection of the finishing temperature, in which can be provided at low cost as a whole.

2 Heating means 7 Hot water storage tanks 21a to 21e Hot water storage temperature sensor 22 Control means 23 Vacuum heat insulating material 24 Foam heat insulating material

Claims (1)

  A hot water storage tank for storing hot water heated by the heating means, a plurality of hot water temperature sensors installed in the height direction on the peripheral wall of the hot water tank to detect the temperature of the hot water, and the hot water temperature detected by the hot water temperature sensor is boiling. When a temperature lower than the first predetermined temperature that requires the additional operation is detected, the heating operation by the heating means is started, and the hot water storage temperature sensor provided at a position lower than the hot water storage temperature sensor ends the additional operation. And a control means for controlling the end of the reheating operation by the heating means when a higher temperature than the second predetermined temperature is detected, the hot water storage for starting the reheating operation from the top of the hot water storage tank A hot water storage tank including a hot water storage temperature sensor which covers the upper outer periphery of the hot water storage tank including a temperature sensor with a vacuum heat insulating material and terminates the boiling operation from the bottom of the hot water storage tank Heat insulating structure of the hot water storage tank, wherein a part periphery that covered with foam insulation

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