JPH033902Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention uses an engine to drive the compressor of a refrigeration system, and recovers the refrigerant condensation heat and engine exhaust heat in the refrigerant hot water heat exchanger. The present invention relates to an engine-driven water heater that heats water in a hot water storage tank and supplies hot water by dissipating heat from a heat medium in an exchanger.

(Prior Art) Conventionally, as a hot water supply system for recovering engine exhaust heat, a refrigerant hot water heat exchanger 5 that condenses refrigerant gas supplied from a compressor 2 is installed in the lower part of a hot water storage tank 11 as shown in FIG. 4, for example. and an exhaust heat water supply heat exchanger 9 that radiates the heat recovered from the exhaust heat of the engine 1 are arranged close to each other, or as shown in FIG. A system in which a hot water supply heat exchanger 5 and a waste heat hot water supply heat exchanger 9 are arranged is known.

However, these conventional water heaters have the following problems due to the mounting positions of the refrigerant hot water heat exchanger 5 and the exhaust heat hot water heat exchanger 9.
That is, as in the conventional example shown in FIG.
In the case where the refrigerant hot water supply heat exchanger 5 and the exhaust heat hot water supply heat exchanger 9 are arranged close to each other at the inner bottom, (1) Since the water temperature in the hot water storage tank 11 rises uniformly, it takes time to reach a predetermined temperature. (2) When the water temperature in the hot water storage tank 11 is below the condensing temperature,
55℃ (when R-22 is used as the refrigerant), which is too low for hot water; (3) It does not have instant performance, so it is not easy to use after using a large amount in a bath. It was hot.

Furthermore, as shown in Fig. 5 (Utility Model Application No. 57-188928), in the hot water storage tank 11, in the case where the exhaust heat hot water supply heat exchanger 9 is arranged in the upper part and the refrigerant hot water supply heat exchanger 5 is arranged in the lower part, ( 1) When hot water is heated by both the refrigerant hot water heat exchanger 5 and the waste heat hot water heat exchanger 9, depending on the position of the waste heat hot water heat exchanger 9, the influence of convection due to the heating of the refrigerant hot water heat exchanger 5 may occur. As a result, the temperature inside the hot water storage tank 11 rises uniformly, and it takes time to reach a predetermined temperature, and there is no instantaneous performance, which not only makes it difficult to use after using a large amount of water for bathing, but also makes it difficult to use the hot water. (2) When hot water is heated only by the exhaust heat hot water heat exchanger 9, , only the water in the upper part of the hot water storage tank 11 can be heated, and the amount of heat storage is reduced.
1. After the water in the upper part is heated to a predetermined temperature, the waste heat is not used to heat the water and is radiated directly through a radiator, etc., resulting in large heat losses.

Furthermore, in both conventional examples, the heat exchanger is installed in the hot water storage tank, so if there is a failure in the heat exchanger, it is necessary to take it out from the hot water storage tank and repair it, which poses maintenance problems.

(Purpose of the invention) The present invention aims to improve instantaneous performance by bringing the temperature of the hot water stored in the hot water storage tank to a predetermined temperature in a short time, and to obtain high-temperature water that can be used as hot water for a bath. Moreover, it is an object of the present invention to provide an engine-driven hot water supply apparatus that can compensate for the hot water temperature at the initial stage of hot water supply operation.

(Structure of the invention) The present invention uses an engine to drive the compressor of the refrigeration system, and a refrigerant hot water heat exchanger that collects refrigerant condensation heat and an exhaust heat hot water heat exchanger that recovers heat from the heat medium. In an engine-driven water heater that heats water stored in a hot water storage tank to supply hot water,
The lower part of the hot water storage tank, the hot water circulation pump, the refrigerant hot water heat exchanger, the waste heat hot water heat exchanger, and the upper part of the hot water storage tank are successively connected in an annular manner outside the hot water storage tank to form a hot water heating circuit, and the hot water heating circuit is configured to form a hot water heating circuit. A flow control valve is interposed at the outlet of the refrigerant hot water heat exchanger between the refrigerant hot water heat exchanger and the exhaust heat hot water heat exchanger in the heating circuit, and the engine exhaust gas during heating is prevented even if the temperature is lower than the set temperature of the flow control valve. The present invention is characterized in that a mechanism for obtaining hot water at a predetermined temperature using only heat is added to the flow rate control valve.

(Embodiment) Hereinafter, an engine-driven water heater according to an embodiment of the present invention will be described with reference to FIG.

This hot water supply device is composed of an air conditioning circuit X and a hot water supply circuit Y.

The air conditioning circuit X includes a compressor 2 for a refrigeration system driven by an engine 1, and a four-way switching valve 3.
, an outdoor heat exchanger 4, a heating expansion valve 6 with a check valve 15, a receiver 8, a cooling expansion valve 7 with a check valve 16, an indoor heat exchanger 10, and an accumulator. 14 are connected in sequence, and the refrigerant is reversibly circulated by switching the four-way switching valve 3.

The hot water supply circuit Y includes a hot water storage tank 11, a water supply circuit A, a hot water supply circuit B, and a stored hot water heating circuit C.

The water supply circuit A is connected to the lower part 11 of the hot water storage tank 11.
It is configured such that tap water can be supplied to b via a pressure reducing check valve 17.

The hot water supply circuit B is configured so that the hot water stored in the upper part 11a of the hot water storage tank can be discharged from the hot water tap 18.

The hot water heating circuit C includes a lower part 11 of the hot water storage tank.
b, the stored hot water circulation pump 12, the refrigerant hot water supply heat exchanger 5, the flow control valve 13, and the exhaust heat hot water supply heat exchanger 9.
and the hot water storage tank upper part 11a are sequentially connected outside the hot water storage tank 11.

The refrigerant hot water supply heat exchanger 5 is interposed in a refrigerant hot water supply circuit D that connects between the high pressure refrigerant pipe 19 on the discharge side of the compressor 2 and the receiver 8, and acts as a condenser, and uses the heat of condensation of the refrigerant to The stored hot water circulating through the stored hot water heating circuit C is heated. Further, the exhaust heat hot water supply heat exchanger 9 includes a heat medium circulation pump 20 and a cooling water heat exchanger 2.
1 and the exhaust gas heat exchanger 22, the engine exhaust heat recovery circuit E is configured, and the hot water circulating in the hot water heating circuit C is heated by the heat medium heated by the engine cooling water and the exhaust gas.

Further, as the flow rate control valve 13, a wax type three-way mixing valve that operates by detecting the hot water temperature at the outlet of the refrigerant hot water supply heat exchanger 5 is adopted. The three-way mixing valve 13 has a high temperature side inlet 13H connected to a throttle mechanism 24.
The low temperature side inlet 13C bypasses the throttling mechanism 24 and connects to the outlet of the refrigerant hot water heat exchanger 5 through the three-way mixing valve outlet 13M for exhaust heat hot water heat exchange. Connected to the inlet of the container 9. Note that in this embodiment, the aperture mechanism 24
Although a capillary tube is used as a capillary tube, a closing valve may be used instead. Further, in this embodiment, a three-way mixing valve is employed as the flow control valve 13, but a three-way branch valve and a two-way valve may also be employed, as shown in FIGS. 2 and 3, respectively. When the two-way valve is employed, the throttle mechanism may not be provided and the valve may be configured to cause internal leakage.
Furthermore, although this embodiment shows a device without a temperature-sensitive tube, it may also have a temperature-sensing tube.

In short, the flow rate control valve 13 keeps the hot water temperature at the outlet of the refrigerant hot water supply heat exchanger 5 constant (approximately 50% in this embodiment).
Any device that can increase or decrease the amount of hot water circulated so as to maintain the temperature at

Next, the operation of the engine-driven water heater according to the illustrated embodiment will be explained.

() When refrigerant hot water supply and engine exhaust heat hot water supply are performed at the same time, the possible operation patterns include cooling hot water supply operation or hot water supply only operation.

The flow of refrigerant during cooling hot water supply operation is shown in the following flow diagram.

2→5→8→7→10→3→14 Furthermore, the flow of refrigerant during hot water supply only operation is shown in the following flow diagram.

2→5→8→6→4→3→14 Then, the low-temperature stored water in the lower part 11b of the hot water storage tank 11 is first sent to the refrigerant hot water supply heat exchanger 5 by the hot water circulation pump 12, where the refrigerant condensation heat is heated by.

At the beginning of operation, the hot water temperature at the outlet of the refrigerant hot water supply heat exchanger 5 is lower than the set temperature (for example, 50°C) of the three-way mixing valve 13, so the stored hot water is passed through the throttle mechanism 24, the high temperature side inlet 13H of the three-way mixing valve 13, The waste heat is led to the hot water supply heat exchanger 9 through the outlet 13M of the three-way mixing valve 13. The flow rate in this case is set to an extremely small flow rate by the throttle mechanism 24, and therefore the hot water temperature at the outlet of the refrigerant hot water supply heat exchanger 5 reaches the set temperature of the three-way mixing valve 13 in a relatively short time. The temperature rises to ℃. Therefore, the exhaust heat exits the hot water supply heat exchanger 9 and is transferred to the upper part 11 of the hot water storage tank 11.
Of the hot water stored from a, the amount of low temperature water is extremely small at the beginning of operation, improving instantaneous performance.

When the hot water temperature at the outlet of the refrigerant hot water supply heat exchanger 5 reaches 50°C or higher, which is the set temperature of the three-way mixing valve 13,
Part or all of the stored hot water flows from the low-temperature side inlet 13c of the three-way mixing valve 13 to the three-way mixing valve outlet 13M, increasing the circulation flow rate and maintaining the hot water temperature at the outlet of the refrigerant hot water supply heat exchanger 5 at 50°C. The flow rate is controlled. The hot water that has exited the refrigerant hot water heat exchanger 5 is further heated to 60 to 70°C or higher in the exhaust heat hot water heat exchanger 9, and is stored from the upper part 11a of the hot water storage tank.

() When only engine exhaust heat hot water supply is performed, the operation pattern may be heating operation or cooling operation.

(b) During heating operation The flow of refrigerant at this time is shown in the flow diagram below.

2 → 3 → 10 → 8 → 6 → 4 → 3 → 14 In this case, the hot water temperature at the outlet of the refrigerant hot water supply heat exchanger 5 is the same as the hot water temperature at the lower part 11b of the hot water storage tank, and the set temperature of the three-way mixing valve 13 The temperature will be below 50℃. Therefore, the hot water is stored in the lower part of the hot water tank 11b,
Stored hot water circulation pump 12, refrigerant hot water supply heat exchanger 5, throttling mechanism 24, high temperature side inlet 13 of three-way mixing valve 13
H, the three-way mixing valve outlet 13M, the exhaust heat hot water supply heat exchanger 9, and the hot water storage tank upper part 11a, and the circulation flow rate is regulated only by the throttle mechanism 24.

In addition, when the hot water temperature at the inlet of the exhaust heat hot water supply heat exchanger 9 is the lowest, when the hot water in the hot water storage tank 11 is being discharged from the hot water supply circuit B, it is equal to the water supply temperature (approximately 10 degrees Celsius). . Therefore, the circulation flow rate may be determined so that the hot water temperature at the outlet of the exhaust heat hot water supply heat exchanger 9 is 70°C. For example, in a 1RT class refrigeration system, if the engine speed under standard heating conditions is 2000 rpm, the engine exhaust heat will be approximately
2000 Kcal/h can be recovered, and the circulation flow rate in this case is given by 2000/(70-10)/60=0.56 l/min. Therefore, the throttle mechanism 24 has a circulating flow rate of
All you have to do is set it so that it is 0.56l/min.

(b) During cooling operation The flow of refrigerant at this time is shown in the flow diagram below.

2 → 3 → 4 → 8 → 7 → 10 → 3 → 14 In cooling operation, if the hot water temperature in the hot water storage tank 11 is below the set temperature, cooling hot water supply operation will be performed.
Hot water supply operation using only engine exhaust heat is performed after the hot water temperature in the hot water storage tank 11 reaches the set temperature.

Therefore, the hot water is stored in the hot water storage tank lower part 11b, the hot water circulation pump 12, the refrigerant hot water heat exchanger 5, the low temperature side inlet 13c of the three-way mixing valve 13, the three-way mixing valve outlet 13M, the exhaust heat hot water heat exchanger 9, and the hot water storage tank. Upper part 1
1a in order, and the circulating flow rate is not restricted by the throttling mechanism 24 and circulates in large quantities. Therefore, the stored hot water at the set temperature is heated by the exhaust heat hot water supply heat exchanger 9 and stored in the hot water storage tank 11.

In this way, the temperature of the hot water in the hot water storage tank 11 gradually increases, and eventually becomes close to the temperature of the heat medium for exhaust heat recovery, and the amount of heat exchanged in the exhaust heat hot water supply heat exchanger 9 gradually decreases. However, the heat corresponding to the decrease will be radiated by a radiator (not shown). but,
There is no problem because the heat is released after sufficient heat has been stored in the hot water storage tank 11.

Next, the results of operating the water heater of this example under the following operating conditions will be shown.

(Operating conditions) Refrigerant: R-22, Engine speed: 2000 rpm, Heat exchangers 4 and 10: Both double pipe/counterflow type, Outside air conditions: Dry bulb temperature 7℃, wet bulb temperature 6℃, Initial tank Internal temperature: 10℃, high pressure: 17Kg/cm ² G (operation results) COP (hot water heating amount/input heat amount) = 1.37 Hot water temperature at positions a, b, c, and d in hot water storage tank 11 versus operating time The changes were as shown in Figure 6. According to this, it can be seen that high temperature water is sequentially stored in the hot water storage tank 11 from the top to the bottom. In other words, instantaneous performance exists.

(Effects of the invention) Next, the effects of the engine-driven water heater of the invention will be described.

According to the present invention, by first heating the stored hot water with refrigerant condensation heat and then heating with engine exhaust heat, fairly high temperature stored hot water can be obtained. lower part 11b of
Since the hot water stored in the tank is heated and the heated hot water is stored from the upper part 11a of the hot water storage tank, the following effects can be obtained.

(a) Since the high temperature water is accumulated from the upper part 11a of the hot water storage tank, it has instantaneous performance, and the temperature is 60 to 70°C or higher, so it can be used sufficiently as hot water for a bath.

(b) Since high-temperature water can be stored in the entire hot water storage tank 11, the amount of heat storage becomes large.

Moreover, a refrigerant hot water supply heat exchanger 5 and an exhaust heat hot water supply heat exchanger 9
A flow rate control valve 13 with a mechanism that allows a specified amount of hot water to be obtained only by the exhaust heat of the engine 1 during heating even if the temperature is lower than the set temperature at the outlet of the refrigerant hot water heat exchanger 5 is installed between the be.

(b) Since a predetermined flow rate (≒a small amount) flows even at the beginning of operation, the time until high-temperature hot water can be stored is shortened.

(b) Even when hot water is supplied using only engine exhaust heat, it is possible to store hot water at a temperature higher than a predetermined temperature, and it can be fully used as hot water.

(c) After heating the inside of the hot water storage tank to a high temperature, the heat is radiated by the radiator, eliminating waste.

Furthermore, if a wax type valve is used as the flow rate control valve 13 as in the illustrated embodiment, the flow rate control valve 13 is self-controlled, thereby eliminating the need for electricity and having the advantage of saving power.

Note that wax type flow control valves operate fully closed or fully open when the temperature is below the set temperature, but as in this example, a predetermined circulating flow rate (a very small amount) can be ensured through the throttling mechanism even when fully closed or fully open. If this is done, the time required to store hot water at a high temperature at the beginning of operation will be shortened, and hot water at a temperature higher than a predetermined temperature can be stored even during hot water supply operation using only exhaust heat from the engine.

[Brief explanation of drawings]

Fig. 1 is a system diagram of an engine-driven water heater according to an embodiment of the present invention, Figs. 2 and 3 are partial views showing a modification of the flow control valve in the system diagram of Fig. 1, and Fig. 4. 5 is a system diagram of a conventional engine-driven water heater, and FIG. 6 is a diagram showing the temperature state of stored hot water in the water heater of FIG. 1...Engine, 2...Compressor, 5...Refrigerant hot water supply heat exchanger, 9...Exhaust heat hot water supply heat exchanger, 11...
Hot water storage tank, 11a...Hot water storage tank top, 11b
...Hot water storage tank lower part, 12...Hot water circulation pump, 13...Flow rate control valve, C...Hot water heating circuit.

Claims (1)

[Scope of utility model registration request] The engine 1 drives the compressor 2 of the refrigeration system, and the refrigerant condensation heat in the refrigerant hot water heat exchanger 5 and the heat medium heat dissipation in the exhaust heat hot water heat exchanger 9 that recovers engine exhaust heat are used to increase the amount of water in the hot water storage tank 11. In an engine-driven water heater that heats stored water to supply hot water, the lower part 11b of the hot water storage tank 11, the stored water circulation pump 12, the refrigerant hot water heat exchanger 5, the exhaust heat hot water heat exchanger 9, and the hot water storage tank. 11 top 1
1a are sequentially connected in an annular manner outside the hot water storage tank 11 to constitute a stored hot water heating circuit C, and the hot water heating circuit C includes the refrigerant hot water supply heat exchanger 5.
A flow control valve 13 is interposed at the outlet of the refrigerant hot water heat exchanger 5 between the exhaust heat hot water heat exchanger 9 and the exhaust heat hot water heat exchanger 9. An engine-driven water heater characterized in that a mechanism for obtaining hot water at a predetermined temperature is added to the flow rate control valve 13.