JP4779260B2 - Heat supply device and water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat supply device including an adsorption heat pump that has an adsorbent that adsorbs and desorbs refrigerant according to the relative humidity of the refrigerant and recovers heat, and is effective when applied to a water heater.
[0002]
[Prior art and problems to be solved by the invention]
The applicant has already filed Japanese Patent Application No. 11-320190 as a heat supply device (hot water heater) equipped with an adsorption heat pump. In this application, the highest required by a user who consumes hot water in a hot water storage tank. It was necessary to store hot water of temperature.
[0003]
That is, the temperature of hot water required in ordinary households is usually about 43 ° C. to 44 ° C., but when special hot water such as hot water for a bathtub is required, hot water of about 60 ° C. is required. . On the other hand, since it is not known when a special hot water request such as hot water occurs when viewed from the water heater, in the above application, it is necessary to always store hot water of 60 ° C. or higher in the hot water storage tank.
[0004]
In addition, in the above application, when the amount of hot water in the hot water storage tank decreases, it is necessary to generate hot hot water and supply it to the hot water storage tank, so it takes time to generate hot water and the amount of hot water in the hot water storage tank decreases. If there is a special hot water requirement such as hot water, the hot hot water may not be supplied with good responsiveness.
[0005]
Moreover, in many cases other than special hot water requests such as hot water among hot water requests from the user, a temperature (for example, 43 ° C. to 44 ° C.) lower than the hot water temperature (for example, 60 ° C.) to be stored in the hot water storage tank. Therefore, storing hot water having the highest temperature required by the user in the hot water storage tank is not necessarily a good measure from the viewpoint of energy saving.
[0006]
An object of this invention is to supply heat stably, aiming at energy saving in a heat supply apparatus in view of the said point.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, an adsorber in which an adsorbent that adsorbs and desorbs a refrigerant according to the relative humidity of the refrigerant enclosed in the casing is stored. An adsorption heat pump (50) that recovers heat from the first heat source and a second heat source that has a higher temperature than the first heat source and supplies heat to the adsorption heat pump (50) (10) and the heat medium heated by the heat of the first heat source recovered by the adsorption heat pump (50) and the heat of the second heat source (10) supplied to the adsorption heat pump (50) are kept warm. Heat storage means (30) for storing, heating means (10b) for supplying the heat medium stored in the heat storage means (30) by heating with heat of the second heat source (10), and heat of the first heat source Means (21c, 22c) for heating the heat medium and the second heat source Supplying means for heating the heat medium (22 d, 21d) and the heat medium circulation circuit disposed in series with the thermocompression medium flows, the heat medium taken out from the heat storage means (30) to the heating means (10b) by The reheating circuit (72), the bypass circuit (73) for bypassing the heating medium (10b) with the heat medium taken out from the heat storage means (30), and the reheating circuit (72) with respect to the heat medium taken out from the heat storage means (30) ) And a switching valve (V5) for switching between the case where it flows to the bypass circuit (73) .
[0008]
Thereby, the heat of the required temperature can be supplied by reheating the heat medium according to the required temperature without increasing the temperature of the heat medium in the heat storage means (30) more than necessary. Therefore, for example, when the present invention is applied to a water heater, heat (heat medium) is generated as compared with a case where hot water at a maximum temperature (for example, 60 ° C.) required by a user is stored in a heat storage means (hot water storage tank). Therefore, heat (warm water) can be stably supplied while reducing the necessary input heat amount.
[0009]
The heating means (10b) may obtain heat from the second heat source (10) and heat the heat medium as in the invention described in claim 2.
[0010]
Further, as in the invention according to claim 3, the adsorption heat pump (50) releases the refrigerant adsorbed by the first adsorbent by absorbing heat from the heat medium as a gas-phase refrigerant, and the second adsorbent. However, the heat may be transferred from the low temperature side to the high temperature side by generating heat while adsorbing the released gas-phase refrigerant.
[0011]
In the invention according to claim 4, the adsorption heat pump (50) includes at least two adsorption units (21, 22) enclosing an adsorbent and a refrigerant, and heat circulating in the adsorption unit (21, 22). A heat exchanger (40) that exchanges heat between the medium and the first heat source is provided, and the two adsorption units (21, 22) are alternately switched to operate, whereby the heat exchanger (40 ) Is recovered from the first heat source, and the heat exchanger (40) is heated to the heat medium for a predetermined time after the operation of the two adsorption units (21, 22) is switched. It is characterized by stopping circulating.
[0012]
Thereby, immediately after switching the operation of the adsorption unit (21, 22), the heat of the heat medium held in the adsorption unit (21, 22) is transferred to the first heat source side via the heat exchanger (40). Can be prevented from being dissipated.
[0013]
Further, as in the invention described in claim 5, the second heat source (10) may be a combustion burner that generates heat by burning fuel, and the first heat source may be natural heat energy existing in nature.
[0014]
In the invention according to claim 6, means (22d, 21d) for heating the heat medium by the heat of the second heat source, means (21c, 22c) for heating the heat medium by the heat of the first heat source, heat storage means ( The heat medium circulation circuit is configured so that the heat medium flows in the order of 30).
The invention according to claim 7 is characterized in that hot water is supplied by the heat supply device according to any one of claims 1 to 6 .
[0015]
Thereby, warm water can be supplied stably, aiming at reduction of the input calorie | heat amount (fossil fuel amount) required for warm water production | generation.
[0016]
Incidentally, the reference numerals in parentheses of each means described above are an example showing the correspondence with the specific means described in the embodiments described later.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
In the present embodiment, the heat supply apparatus according to the present invention is applied to a general household water heater, and FIG. 1 is a schematic diagram of the water heater according to the present embodiment.
[0018]
Reference numeral 10 denotes a combustion burner (second heat source) that generates heat by burning fossil fuel such as kerosene or gas, and reference numeral 10a denotes a combustion gas and a heat medium (burner 10). In this embodiment, it is a first heater that heats the heat medium by exchanging heat with water mixed with an ethylene glycol antifreeze solution), and 10b is a hot water supplied from a hot water storage tank 30 described later and the burner 10 It is the 2nd heater (heating means) which heat-exchanges combustion gas and reheats warm water.
[0019]
Reference numeral 20 denotes an adsorber that moves heat by using evaporation and condensation of a refrigerant (in this embodiment, water). The adsorber 20 includes first and second adsorption units 21, 22 as shown in FIG. And the first to fourth switching valves V1 to V4 for switching the heat medium flow.
[0020]
Here, the first and second adsorption units 21 and 22 are substantially vacuum casings 21a and 22a filled with a refrigerant, and an adsorbent that adsorbs and desorbs the refrigerant stored in the casings 21a and 22a (this embodiment). Then, silica gel) 21b, 22b, first heat exchangers 21c, 22c for exchanging heat between the heat medium and the adsorbents 21b, 22b, and the heat exchange between the refrigerant sealed in the casings 21a, 22a and the heat medium. It is a well-known thing which consists of 2 heat exchangers 21d and 22d.
[0021]
As is well known, the adsorbents 21b and 22b adsorb and desorb refrigerant according to the relative humidity of the adsorbents 21b and 22b (relative humidity in the vicinity of the surface of the adsorbent). Usually, the relative humidity is large. Then, the gas-phase refrigerant is adsorbed, and the adsorbed refrigerant is desorbed when the relative humidity decreases. For this reason, when desorbing the refrigerant adsorbed on the adsorbent, the adsorbent is generally heated to reduce the relative humidity.
[0022]
In FIG. 1, reference numeral 30 denotes a hot water storage tank (heat storage means) for storing hot water for hot water supply (hot water supply), and the hot water tank 30 automatically stores a predetermined amount or more of hot water at all times. Water is being supplied.
[0023]
Reference numeral 40 denotes an outdoor heat exchanger (hereinafter abbreviated as an outdoor unit) that exchanges heat between the heat medium and the outdoor air (outside air). In the present embodiment, the outdoor unit 40 and the adsorber 20 allow the outside air ( An adsorption heat pump 50 that recovers heat from a first heat source (range surrounded by a chain line in FIG. 1) is configured.
[0024]
Reference numeral 60 denotes an in-tank heat exchanger for exchanging heat between the heat medium and the hot water in the hot water storage tank 30, 71 denotes a hot water discharge circuit for taking out the hot water in the hot water storage tank 30 from the upper side of the hot water storage tank 30, and 72 A reheating circuit for supplying hot water extracted from the hot water storage tank 30 to the second heater 10b, and 73 supplies the hot water extracted from the hot water storage tank 30 to the mixing faucet 75, which will be described later, bypassing the second heater 10b. It is a bypass circuit. 74 is a cold water circuit for supplying cold water supplied from the water supply to the mixing plug 75, and the mixing plug 75 adjusts the temperature of the hot water supply by adjusting the mixing ratio of cold water and hot water.
[0025]
P1 to P3 are first to third pumps that circulate the heat medium, and V5 is a switch that switches between a case where the hot water taken out from the hot water storage tank 30 is circulated to the reheating circuit 72 and a case where it is circulated to the bypass circuit 73. It is a valve. The first to third pumps P1 to P3, the first to fifth switching valves V1 to V5, and the burner 10 are controlled by an electronic control device (not shown).
[0026]
Next, the operation of the water heater according to the present embodiment and its features will be described.
[0027]
In order to generate warm water, the first to third pumps P1 to P3 and the burner 10 are operated, and the first to fourth switching valves V1 to V4 in the adsorber 20 are indicated by a solid line in FIG. And a state indicated by a broken line. The predetermined time is appropriately selected in consideration of the time required until the water adsorption amount of the adsorbents 21b and 22b is saturated, the time required for desorbing the adsorbed water, and the like.
[0028]
Thereby, the heat recovered (absorbed) from the outside air when the refrigerant evaporates is the heat of adsorption equivalent to the heat of condensation generated when the refrigerant is adsorbed by the adsorbents 21b and 22b, and thus the first heat exchangers 21c and 22c. It is consumed for heating the hot water in the hot water storage tank 30 via.
[0029]
On the other hand, the vapor refrigerant is desorbed from the adsorbents 21b and 22b by the heat supplied (input) to the adsorption heat pump 50 (adsorbents 21b and 22b) from the burner 10.
[0030]
And it collect | recovers by the heat medium via 2nd heat exchanger 21d, 22d as condensation heat which is generated when a vapor | steam refrigerant | coolant is cooled and condensed in 2nd heat exchanger 21d, 22d, and the collect | recovered heat is outside air. It is given to the hot water in the hot water storage tank 30 together with the heat recovered from the water.
[0031]
At this time, if the coefficient of performance of the adsorption heat pump 50 is 1.6, the amount of heat supplied from the burner 10 is Q (J), and the amount of heat recovered from the outside air is 0.6Q (J). The amount of heat given to the hot water is 1.6Q (J).
[0032]
Further, most of the heat given to the hot water in the hot water storage tank 30 is given as the heat of condensation of the refrigerant in the adsorber 20 (adsorption heat pump 50), so the temperature of the heat (the hot water temperature in the hot water storage tank 30). Is a temperature that is higher than the outside air temperature (the temperature of the first heat source) and lower than the temperature of the heat applied from the burner 10 although it varies depending on the outside air temperature.
[0033]
Specifically, assuming that the temperature of heat supplied (input) from the burner 10 to the adsorption heat pump 50 (adsorbents 21b and 22b) is 80 ° C., the hot water temperature in the hot water storage tank 30 when the outside air temperature is 30 ° C. Is about 50 ° C. and the outside air temperature is 10 ° C., the hot water temperature in the hot water storage tank 30 is about 30 ° C.
[0034]
For this reason, when the outside air temperature is high in summer (for example, when the outside air temperature is 30 ° C. or higher), and other than a special hot water request such as hot water (when the required hot water temperature is about 43 ° C.) The hot water taken out from the hot water storage tank 30 may be supplied to the mixing tap 75 as it is, bypassing the second heater 10b.
[0035]
In addition, when the outside air temperature is high in summer (for example, when the outside air temperature is 30 ° C. or higher), and when there is a special hot water request such as hot water (when the required hot water temperature is about 60 ° C.), What is necessary is just to reheat the hot water taken out from the hot water storage tank 30 in the 2nd heater 10b, and to supply it to the mixing faucet 75.
[0036]
On the other hand, when the outside air temperature is low in winter or the like (for example, when the outside air temperature is 10 ° C. or lower), when the hot water temperature in the hot water storage tank 30 is equal to or higher than the required hot water temperature, the hot water in the hot water storage tank 30 is second-heated. The hot water temperature in the hot water storage tank 30 is less than the required hot water temperature, the hot water in the hot water storage tank 30 is reheated in the second heater 10b, and then mixed. What is necessary is just to supply to the faucet 75.
[0037]
As described above, in this embodiment, hot water at the required hot water temperature is supplied by reheating (cooking) according to the required hot water temperature without increasing the hot water temperature in the hot water storage tank 30 more than necessary. Therefore, compared with the case where the hot water of the highest temperature (for example, 60 degreeC) which a user requires is stored in the hot water storage tank 30, the calorie | heat amount for producing | generating hot water can be reduced.
[0038]
Therefore, in the present embodiment, hot water can be stably supplied while recovering heat from the outside air and reducing the amount of input heat (fossil fuel amount) necessary for generating hot water.
[0039]
Incidentally, according to the inventors' calculations, the temperature of tap water is set to 7 ° C., 100 liters of hot water at 60 ° C. and 100 liters of hot water at 43 ° C. are supplied, and the coefficient of performance of the adsorption heat pump 50 is 1. 6 and the hot water temperature in the hot water storage tank 30 is 30 ° C., the water heater according to the related art requires 8900 kcal of heat, whereas in this embodiment, it may be 7200 kcal. Therefore, in this embodiment, energy consumption can be reduced by about 20% compared to the conventional case.
[0040]
(Second Embodiment)
In the above-described embodiment, the heat source (burner 10) for heating the hot water taken out from the hot water storage tank 30 and the heat source (burner 10) supplied to the adsorption heat pump 50 are shared, but this embodiment is shown in FIG. As shown in FIG. 2, a heat source (burner 10) for the second heater 10b for heating the hot water taken out from the hot water storage tank 30 and a heat source (burner 10) for the first heater 10a supplied to the adsorption heat pump 50 are respectively provided. It is provided independently.
[0041]
(Third embodiment)
In the above-described embodiment, the refrigerant in the liquid phase state is enclosed in the adsorption units 21 and 22, but in the present embodiment, the refrigerant in the gas phase state is enclosed in the adsorption units 21 and 22 and as shown in FIG. The adsorbents 21e and 22e that exchange heat with the heat medium circulating in the second heat exchangers 21d and 22d are filled and bonded to the surfaces of the second heat exchangers 21d and 22d. The adsorbents 21e and 22e and the adsorbents 21b and 22b are not limited to the same adsorbent.
[0042]
As a result, the adsorbents 21e and 22e desorb the adsorbed refrigerant from the heat medium circulating in the second heat exchangers 21d and 22d, so that the heat circulating in the second heat exchangers 21d and 22d. The medium is cooled.
[0043]
That is, in the present embodiment, in the adsorption units 21 and 22, the adsorbents 21e and 22e absorb the heat absorbed from the heat medium and release the refrigerant as a gas phase refrigerant, and the adsorbents 21b and 22b release the gas released. The heat is transferred from the low temperature side to the high temperature side in the adsorber 20 by generating heat while adsorbing the phase refrigerant.
[0044]
(Fourth embodiment)
In the present embodiment, as shown in FIG. 5, the bypass circuit 76 that circulates the heat medium by bypassing the outdoor unit 40 with respect to the above-described embodiment, the electromagnetic valve V11 that opens and closes the bypass circuit 76, and the heat medium is outdoor. The electromagnetic valve V12 for preventing distribution in the vessel 40 is provided.
[0045]
Next, the characteristic operation of this embodiment and its effect will be described.
[0046]
As described above, the adsorber 20 continuously absorbs heat from the outside air in the outdoor unit 40 by switching the first to fourth switching valves V1 to V4 in the adsorber 20 every predetermined time. Immediately after switching the -4 switching valves V1 to V4, there is a heat medium having the same temperature as the hot water in the hot water storage tank 30 in the second heat exchangers 21d and 22d. The heat of the heat medium having the same temperature is radiated from the outdoor unit 40 into the outside air.
[0047]
Therefore, in the present embodiment, the electromagnetic valve V11 is opened and the electromagnetic valve V12 is closed for a predetermined time from when the first to fourth switching valves V1 to V4 are switched, whereby the second heat exchangers 21d and 22 The heat medium having the same temperature as the hot water in the hot water storage tank 30 is prevented from flowing into the outdoor unit 40, and the heat of the heat medium having the same temperature as the hot water in the hot water storage tank 30 is radiated into the outside air. Is suppressed.
[0048]
Incidentally, the predetermined time is determined based on the time required for the heat medium in the second heat exchangers 21d and 22 to be completely replaced.
[0049]
FIG. 4 shows the case where the present embodiment is applied to the first embodiment (FIG. 1), but the present embodiment can also be applied to the second and third embodiments.
[0050]
(Other embodiments)
In the above-described embodiment, heat is recovered from the outside air as the first heat source. However, the present invention is not limited to this, and natural heat energy existing in the natural world such as rivers, geothermal heat, solar heat, etc. The hot water may be heated by collecting waste heat from equipment such as an engine or a fuel cell.
[0051]
In the above-described embodiment, the burner 10 for burning fossil fuel is used as the second heat source. However, the present invention is not limited to this, and the temperature of the second heat source is higher than that of the first heat source. For example, an electric heater may be used.
[0052]
Moreover, in the above-mentioned embodiment, although this invention was applied to the water heater, this invention is not limited to this, For example, you may apply to a heating apparatus etc.
[0053]
In the above-described embodiment, silica gel is used as the adsorbent. However, the present invention is not limited to this, and activated carbon, zeolite, activated alumina, or the like may be used as the adsorbent.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a hot water supply / air conditioning system during cooling and warm water heating according to a first embodiment of the present invention.
FIG. 2 is a schematic view of an adsorber during cooling and warm water heating according to the first embodiment of the present invention.
FIG. 3 is a schematic diagram of a hot water supply / air conditioning system during cooling and warm water heating according to a second embodiment of the present invention.
FIG. 4 is a schematic diagram of an adsorber during cooling and warm water heating according to a third embodiment of the present invention.
FIG. 5 is a schematic diagram of a hot water supply / air conditioning system during cooling and warm water heating according to a fourth embodiment of the present invention.
[Explanation of symbols]
10 ... Burner (second heat source), 20 ... Adsorber,
30 ... Hot water storage tank (heat storage means), 40 ... Outdoor heat exchanger,
50: Adsorption heat pump.

Claims (7)

It has an adsorber (20) containing an adsorbent that adsorbs and desorbs the refrigerant in accordance with the relative humidity of the refrigerant sealed in the casing (21a, 22a), and recovers heat from the first heat source. Adsorption heat pump (50);
A second heat source (10) having a higher temperature than the first heat source and supplying heat to the adsorption heat pump (50);
The heat medium heated by the heat of the first heat source recovered by the adsorption heat pump (50) and the heat of the second heat source (10) supplied to the adsorption heat pump (50) is kept warm. Heat storage means (30) to perform,
Heating means (10b) for heating and supplying the heat medium stored in the heat storage means (30) with the heat of the second heat source (10) ;
Means (21c, 22c) for heating the heat medium by the heat of the first heat source and means (22d, 21d) for heating the heat medium by the heat of the second heat source are arranged in series with respect to the heat medium flow. Heat medium distribution circuit,
An additional cooking circuit (72) for supplying the heating medium (10b) with the heat medium taken out from the heat storage means (30);
A bypass circuit (73) for bypassing the heating means (10b) with the heat medium taken out from the heat storage means (30);
A switching valve (V5) for switching between a case where the heat medium taken out from the heat storage means (30) is distributed to the additional cooking circuit (72) and a case where the heat medium is distributed to the bypass circuit (73) is provided. Heat supply device. The second heat source (10) can supply heat having a temperature higher than the temperature of the heat medium stored in the heat storage means (30),
The heat supply device according to claim 1, wherein the heating means (10b) heats the heat medium by obtaining heat from the second heat source (10).   The adsorption heat pump (50) releases the refrigerant adsorbed by the first adsorbent by absorbing heat from the heat medium as a gas-phase refrigerant, while the second adsorbent adsorbs the released gas-phase refrigerant. The heat supply device according to claim 1, wherein the heat supply device is configured to move heat from a low temperature side to a high temperature side by generating heat. The adsorption heat pump (50) includes at least two adsorption units (21, 22) in which an adsorbent and a refrigerant are enclosed, a heat medium circulating in the adsorption unit (21, 22), and the first heat source. Through the heat exchanger (40) by switching the two adsorption units (21, 22) alternately and operating them. Recovering heat from the first heat source;
Further, the circulation of the heat medium to the heat exchanger (40) is stopped for a predetermined time after the operation of the two adsorption units (21, 22) is switched. Item 4. The heat supply device according to any one of Items 1 to 3. The second heat source (10) is a combustion burner that generates heat by burning fuel,
The heat supply device according to any one of claims 1 to 4, wherein the first heat source is natural heat energy existing in nature. Means (22d, 21d) for heating the heat medium by the heat of the second heat source, means (21c, 22c) for heating the heat medium by the heat of the first heat source, and heat storage means (30) in this order The heat supply device according to claim 1, wherein the heat medium circulation circuit is configured to flow. Hot water is supplied by the heat supply device according to any one of claims 1 to 6 .

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