JP2008209038A - Engine-driven heat pump system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine-driven heat pump system capable of suppressing heat island phenomenon. <P>SOLUTION: In this engine-driven heat pump system 100 comprising an engine 11, a compression-type heat pump circuit 5 utilizing shaft power of the engine 11 as power source of a compressor 1 compressing a refrigerant X, and comprising an underground heat releasing operation means A capable of exerting a condensation heat releasing operation for releasing the condensation heat generated in a condenser 2 disposed in the compression type heat pump circuit 5 into the ground, the underground heat releasing operation means A is constituted so that it can exert an exhaust heat releasing operation for releasing exhaust heat of the engine into the ground. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes an engine and a compression heat pump circuit that uses shaft power of the engine as a power source of a compressor that compresses refrigerant, and condenses heat generated in a condenser included in the compression heat pump circuit. The present invention relates to an engine-driven heat pump system (hereinafter sometimes simply referred to as a heat pump system) provided with underground heat radiation operation means capable of performing a condensed heat release operation.

  The heat pump system includes a compressor that is driven by an engine and compresses the refrigerant, a condenser that releases heat of condensation from the refrigerant compressed by the compressor and generates warm heat such as warm air and hot water, and the refrigerant. A compression heat pump circuit that circulates the refrigerant in order is provided in an expansion valve that expands and an evaporator that absorbs heat of vaporization in the refrigerant expanded by the expansion valve to generate cold air and hot water. The warm heat generated in the condenser can be used for heating and hot water supply, and the cold heat generated in the evaporator can be used for cooling.

  As such a heat pump system, there is known a heat pump system that can dissipate condensation heat generated in a condenser provided in a compression heat pump circuit to the ground by an embedded heat exchanger. In such a heat pump system that uses geothermal heat, the COP can be improved (see Patent Document 1).

  There is also known a heat pump system that uses engine shaft power as a power source of a compressor in the compression heat pump circuit (see Patent Document 2). The heat pump system of Patent Document 2 includes a heat storage tank that stores exhaust heat in a form in which hot water heated by engine exhaust heat is stored, and surplus exhaust heat that cannot be stored in the heat storage tank of the engine exhaust heat by a radiator. It is configured to release to the atmosphere. In this heat pump system, in addition to the effect of improving the COP, the heat held by the exhaust heat can be effectively used as hot water.

JP 2001-74316 A Japanese Patent Laid-Open No. 2002-5528

However, in the system of Patent Document 2, surplus exhaust heat that could not be recovered as hot water is released to the atmosphere. Therefore, when the heat pump system is installed in a place where the urban ground surface is covered with asphalt or the like, releasing the excess exhaust heat to the atmosphere in this way is one factor that causes a heat island phenomenon in which the temperature rises. .
Furthermore, although the atmospheric temperature is high and the underground temperature is low in summer, it is preferable to make good use of this state.

  This invention is made | formed in view of said subject, The objective is to provide the engine drive type heat pump system which can suppress a heat island phenomenon.

  In order to achieve the above object, an engine-driven heat pump system according to the present invention includes an engine, and a compression heat pump circuit that uses shaft power of the engine as a power source of a compressor that compresses a refrigerant. It has a ground heat radiation operation means capable of performing a condensation heat release operation that releases the condensation heat generated in the condenser provided in the heat pump circuit to the ground, and the first characteristic configuration thereof is the ground heat radiation operation means, The exhaust heat release operation for releasing the exhaust heat of the engine into the ground is configured to be executable.

According to the first characteristic configuration described above, when the heat demand is low and the exhaust heat of the engine cannot be effectively used, such as in summer, the conventional feature is provided for discharging the condensed heat into the ground. Excess heat that cannot be used effectively out of the exhaust heat generated by driving the engine by effectively using the underground heat radiation operation means and executing the exhaust heat release operation by the underground heat radiation operation means Can be released into the ground.
As a result, the temperature rise in the atmosphere can be reduced compared with the case where excess exhaust heat is released to the atmosphere, so the engine-driven heat pump system is installed in a place where the ground surface such as urban areas is covered with asphalt etc. However, the heat island phenomenon can be suppressed.
In addition, taking advantage of the fact that the underground temperature is lower than the atmospheric temperature, the engine exhaust heat is released into the ground at a lower temperature than the atmosphere in the summer, so the engine can be effectively guided to the low temperature side to suppress overheating, etc. .

  A second characteristic configuration of the engine-driven heat pump system according to the present invention includes, in addition to the first characteristic configuration, a heat storage tank that stores the exhaust heat of the engine, and the underground heat radiation operation unit stores heat in the heat storage tank. The exhaust heat release operation is performed when the amount is full.

According to the second characteristic configuration, when the underground heat radiation operation means determines that the heat storage amount of the heat storage tank is not full, the exhaust heat of the engine is stored in the heat storage tank and effectively used for hot water supply or the like. it can.
In addition, when the underground heat radiation operation means determines that the heat storage amount of the heat storage tank is full, it is possible to suppress the release of useless exhaust heat to the atmosphere by releasing only excess exhaust heat into the ground. Can do.
As a result, surplus exhaust heat can be appropriately released into the ground while giving priority to heat storage of the engine exhaust heat in the heat storage tank.

  According to a third characteristic configuration of the engine-driven heat pump system according to the present invention, in addition to the first characteristic configuration, the underground heat dissipation operation means includes the condensed heat release operation, the exhaust heat release operation, and the second feature configuration. Are configured to be executable separately.

According to the third feature configuration, since the condensed heat releasing operation can be executed regardless of whether the exhaust heat releasing operation is being executed, the condensation is performed whenever cold heat is generated by the heat pump circuit. Heat can be released into the ground to reduce atmospheric temperature rise.
On the other hand, the exhaust heat release operation can be executed regardless of whether or not the condensation heat release operation is being executed. Therefore, whenever there is little demand for hot water supply, the exhaust heat of the engine is released into the ground and Temperature rise can be reduced.

An embodiment of an engine driven absorption heat pump system 100 according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an engine-driven heat pump system 100.
As shown in FIG. 1, the heat pump system 100 includes an engine 11 and a compression heat pump circuit 5 that uses shaft power of the engine 11 as a power source of the compressor 1 that compresses the refrigerant X.
The compression heat pump circuit 5 includes a compressor 1 that compresses the refrigerant X, a condenser 2 that dissipates heat from the refrigerant X, an expansion valve 3 that expands the refrigerant X, and an evaporator 4 that absorbs heat from the refrigerant X in this order. It is configured to circulate.

  That is, the evaporated refrigerant X is compressed in the compressor 1 to be in a high temperature and high pressure state, and then, the refrigerant X in the high temperature and high pressure state dissipates heat to the hot water H flowing in the heat transfer pipe 2a in the condenser 2. Then, the condensed refrigerant X expands in the expansion valve 3 to be in a low temperature and low pressure state, and then the refrigerant X in the low temperature and low pressure state flows in the heat transfer tube 4a in the evaporator 4. It is configured to operate in such a form that it absorbs heat from the cooling water C that evaporates and evaporates, and the evaporated refrigerant X is supplied to the compressor 1 again. And in this compression heat pump circuit 5, while the warm water H is heated in the condenser 2, the warm heat which can be utilized for hot water supply or heating is generated, and the cold water C is cooled in the evaporator 4 It is possible to generate cold energy that can be used for cooling.

The engine 11 combusts the fuel G, which is a natural gas city gas, and outputs a shaft output as a driving force of the compressor 1. Further, the exhaust heat of the engine 11 is used in a form in which hot water HW stored in a hot water storage tank 31 (an example of a heat storage tank) described later is heated.
Furthermore, the generator 15 which drives the compressor 1 with the shaft output of the surplus engine 11 by driving the compressor 1 is provided, and the electric power generated by the generator 15 is supplied to the auxiliary machine of the heat pump system 100 and other electric power loads. Is done.

  The cooling system of the engine 11 employs a water cooling system that is cooled by the jacket water JW that circulates through the cooling path 12 by the operation of the circulation pump 13. The cooling passage 12 is heated by the exhaust gas heat exchanger 22 that heats the jacket water JW heated by cooling the engine 11 by the exhaust gas E of the engine 11 that flows through the exhaust gas passage 14, and the exhaust gas E. A hot water supply heat exchanger 21 that heats hot water HW stored in a hot water storage tank 31 to be described later by the jacket water JW is sequentially connected.

  The hot water supply heat exchanger 21 heats the hot water HW by exchanging heat between the jacket water JW and hot water HW stored in a hot water storage tank 31 to be described later, and the exhaust heat of the engine 11 is heated by the hot water HW. It is configured to collect.

A hot water supply circulation path 32 that sequentially connects the lower part of the hot water tank 31, the hot water supply heat exchanger 21, and the upper part of the hot water storage tank 31 is provided, and a circulation pump 35 that circulates the hot water HW through the hot water supply water circulation path 32. Is provided. Then, the circulation pump 35 is operated, and the relatively low temperature hot water HW stored in the lower side of the hot water tank 31 is supplied to the hot water supply heat exchanger 21 to recover the exhaust heat of the engine 11 to obtain a high temperature. After being heated, the hot water storage water 31 is stored in the hot water storage tank 31 so as to form a temperature stratification from the upper part to the lower part.
The hot water supply water HW stored in the upper part of the hot water storage tank 31 is supplied to the hot water supply part 61 through the hot water supply passage 34 connected to the upper part of the hot water storage tank 31, so that the hot water supply to the hot water supply part 61 is performed. Done. Further, in the lower part of the hot water tank 31, the water supply SW that is consumed by the hot water supply is replenished from the water supply path 36.

A temperature sensor 53 for detecting the temperature of the hot water HW is provided below the hot water tank 31.
The control device 50 is configured to determine the amount of heat stored in the hot water tank 31 based on the detection result of the temperature sensor 53, and the hot water HW detected by the temperature sensor 53 provided in the lower part of the hot water tank 31. Is equal to the upper limit temperature of the hot water tank 31, it is determined that the amount of heat stored in the hot water tank 31 is full, and the temperature of the hot water HW detected by the temperature sensor 53 is less than the upper temperature limit of the hot water tank 31. When it is, it determines with the said heat storage amount not reaching full.

  Further, in the present heat pump system 100, the control device 50 functions as underground heat radiation operating means A capable of performing a condensed heat release operation for releasing the condensation heat generated in the condenser 2 into the ground, and the underground heat dissipation. The operation means A is configured to be able to execute an exhaust heat release operation for releasing the exhaust heat of the engine 11 into the ground. Hereinafter, a description will be given of a configuration in which the underground heat radiation operation means A works to enable the below-described underground heat radiation operation and exhaust heat release operation.

An underground heat radiation circuit 51 for connecting the condenser 2, the hot water supply heat exchanger 21, and the buried heat exchanger 23 capable of releasing heat into the ground in order is provided. Is provided with a circulation pump 7 for circulating the heat medium R.
Furthermore, the underground heat radiation circulation path 51 is provided with a condenser bypass path 8 that bypasses the condenser 2 and a hot water supply heat exchanger bypass path 9 that bypasses the hot water supply heat exchanger 21. The bypass passage 8 is provided with a control valve 42 for interrupting the circulation of the heating medium R, and the hot water supply heat exchanger bypass passage 9 is provided with a control valve 44 for interrupting the circulation of the heating medium R. Further, the underground heat radiation circuit 51 includes a control valve 41 that blocks the circulation of the heating medium R to the condenser 2 and a control valve 43 that blocks the circulation of the heating medium R to the hot water supply heat exchanger 21. Is provided.

  Therefore, in the underground heat radiation circuit 51, with the circulation pump 7 operated, the control valve 41 is opened and the control valve 42 is closed, so that the heat medium R circulates through the condenser 2. The heat medium R flows through the condenser bypass 8 by closing the control valve 41 and opening the control valve 42. Further, in the underground heat radiation circuit 51, with the circulation pump 7 activated, the control valve 43 is opened and the control valve 44 is closed, so that the heat medium R flows through the hot water supply heat exchanger 21. On the other hand, when the control valve 43 is closed and the control valve 44 is opened, the heating medium R flows through the hot water supply heat exchanger bypass 8.

  That is, the condenser circulation state and the condenser in which the heat medium R circulating between the buried heat exchanger 23 is circulated to the condenser 2 by switching the open / close state of the control valves 41 and 42 by the underground heat radiation operation means A. It is possible to selectively switch the condenser bypass state to be circulated through the bypass path 8. Furthermore, hot water supply water heat exchange for circulating the heat medium R circulating between the embedded heat exchanger 23 to the hot water supply water heat exchanger 21 by switching the open / close state of the control valves 43 and 44 by the underground heat radiation operation means A. It is possible to alternatively switch between the hot water supply heat exchanger bypass state and the hot water hot water heat exchanger bypass state that flows through the hot water hot water exchanger bypass passage.

When the heat medium R circulates in the above-described condenser circulation state, the heat medium R circulates through the condenser 2 through the control valve 41 and collects condensation heat, and then circulates through the embedded heat exchanger 23 to condense heat. To the ground. The circulation corresponds to the condensation heat release operation described later.
When the heat medium R circulates in the hot water supply heat exchanger circulation state described above, the heat medium R flows through the hot water supply heat exchanger 21 via the control valve 43 and surplus exhaust heat of the engine 11 (to the hot water storage tank 31). After recovering the exhaust heat that cannot be recovered, the exhaust heat is discharged into the ground through the embedded heat exchanger 23. The circulation corresponds to the exhaust heat release operation described later.
In short, the condensation heat release operation and the exhaust heat release operation can be executed separately.

  Next, specific examples of the condensation heat release operation for releasing the condensation heat of the condenser 2 into the ground and the exhaust heat release operation for releasing the exhaust heat into the ground will be described.

[Condensation heat release operation]
The condensation heat release operation is executed particularly when cold heat is generated by the heat pump circuit 5 such as in summer, and the condensation heat of the condenser 2 that cannot be effectively used is discharged into the ground. The underground discharge operation means A operates the circulation pump 7, opens the control valve 41, closes the control valve 42, and distributes the heat medium R in the underground heat radiation circuit 51 in the condenser circulation state. Then, after the heat medium R recovers the condensation heat in the condenser 2 through the open control valve 41 in the underground heat radiation circuit 51, the heat medium R repeats the circulation of releasing the condensation heat in the embedded heat exchanger 23. Thus, the condensation heat release operation is executed. Thereby, the condensation heat is released into the ground without being released into the atmosphere, and the temperature rise in the atmosphere can be reduced. Further, the heat medium R recovers the condensation heat of the condenser 2, lowers the temperature of the refrigerant X circulating in the condenser 2, and supplies the low-temperature refrigerant X to the evaporator 4. Increase the amount of cold generated. At this time, the recovery of the condensation heat by the heat medium R is performed based on the temperature in the ground that is lower than the atmosphere, which is advantageous in that the condenser 2 has a low temperature.

[Exhaust heat release operation]
The exhaust heat release operation is executed particularly when the demand for hot water supply is low, such as in summer, and discharges excess exhaust heat that cannot be used effectively among the exhaust heat generated by driving the engine 11 into the ground. When the underground heat radiation operation means A determines that the amount of heat stored in the hot water tank 31 is full based on the detection result of the temperature sensor 53 provided in the lower part of the hot water tank 31, the circulation pump 7 is operated, With the control valve 43 in the open state and the control valve 44 in the closed state, the heating medium R is circulated in the hot water / water heat exchanger flow state. And after the heat medium R collect | recovers surplus waste heat in the hot water supply water heat exchanger 21 via the control valve 43 in an open state in the underground heat radiation circuit 51, the above-mentioned surplus waste heat is removed by the embedded heat exchanger 23. By repeating the circulation of releasing, the condensed heat releasing operation is executed. Thereby, the excess exhaust heat is released into the ground without being released into the atmosphere, and the temperature rise in the atmosphere can be reduced. Further, since the excess exhaust heat can be released well, the engine 11 can be effectively cooled. At this time, the recovery of excess exhaust heat by the heat medium R is performed based on the temperature in the ground that is lower than the atmosphere, which is advantageous in that the temperature of the engine 11 is lowered.

  The condensation heat release operation and the exhaust heat release operation may be executed alternatively or simultaneously. That is, in the heat pump system 100, the heat medium R flows through one of the condenser 2 and the hot water supply heat exchanger 21 to recover either the condensed heat or the excess exhaust heat, and the embedded heat exchanger. In the first operating state in which heat is released in 23, the heat medium R sequentially flows through the condenser 2 and the embedded heat exchanger 21 to recover both the condensed heat and the excess exhaust heat, and in the embedded heat exchanger 23 It is possible to switch to the second operating state that releases heat.

  The switching between the first operation state and the second operation state is performed so that the overall efficiency is increased according to parameters such as the load of the heat pump circuit 5, the temperature of the refrigerant X, the output of the engine 11 and the temperature of the exhaust gas E. Can do.

  In addition, both the control valves 41 and 42 are opened and their opening degrees are adjusted, so that the heat medium R flows through the condenser 2 and the condenser bypass 8 at the same time, and the total flow rate of the heat medium R is reduced. The flow rate ratio to the condenser 2 can be adjusted. Further, both control valves 43 and 44 are opened and their opening degrees are adjusted, whereby the hot water supply heat exchanger 21 and the hot water supply heat exchanger bypass 9 are simultaneously circulated, and the total flow rate of the heat medium R is determined. The flow rate ratio to the hot water supply water heat exchanger 21 can be adjusted. Therefore, in the second operating state, it is possible to adjust the flow rate ratio to the condenser 2 and the hot water supply heat exchanger 21 with respect to the total flow rate of the heat medium R, and to control the amount of heat recovered in each. It is also possible to individually adjust the discharge amounts of exhaust heat and condensation heat.

  As described above, it is considered that the condensed heat and surplus exhaust heat released into the ground by the buried heat exchanger 23 in the summer can be collected in the winter about six months later. It is considered that the coefficient of performance of the heat pump system 100 throughout the year can be improved by using the underground with the exchanger 23 as the heat source of the heat pump system 100.

[Another embodiment]
(1)
In the above embodiment, the condensation heat and surplus exhaust heat are released into the ground by one embedded heat exchanger 23, but it is not necessary to perform it separately in one embedded heat exchanger 23, and a plurality of embedded heat exchangers are installed. Then, the heat radiation position to the ground may be dispersed.

(2)
In the above embodiment, the cooling path 12 through which the jacket water JW flows is configured to be connected to the exhaust gas heat exchanger 22 and collect the exhaust gas exhaust heat, but may not be connected to the exhaust gas heat exchanger 22 separately. . Further, the exhaust gas E and the hot water supply water HW may be configured to directly exchange heat.

(3)
In the above-described embodiment, in the compression heat pump circuit 5, the refrigerant X that has been expanded by the expansion valve 3 into the low-temperature and low-pressure state at the site indicated by the reference numeral 4 with the flow direction of the refrigerant X as the direction shown in FIG. It is configured to function as an evaporator that evaporates and cools the cold water, and is configured to perform cooling or the like by cooling the cold water that is cooled by the evaporator. 1 is switched to a direction opposite to the direction shown in FIG. 1, and the portion indicated by reference numeral 4 functions as a condenser that condenses the refrigerant X that has become a high-temperature and high-pressure state in the compressor 1 and heats the hot water. You may comprise so that heating etc. may be performed with the temperature of the hot water heated with the said condenser.

(4)
In the above embodiment, the heat of condensation of the condenser 2 and the exhaust heat of the engine 11 are recovered by the heat medium R circulating in the underground heat radiation circuit 51 and released into the ground in the buried heat exchanger 23. Although it is configured, a radiator that releases the condensation heat and exhaust heat to the atmosphere can be provided separately as a backup when the condensation heat and exhaust heat cannot be released to the ground due to some reason such as failure. I do not care.

  The engine-driven heat pump system of the present invention can be effectively used as an engine-driven heat pump system that can suppress the heat island phenomenon.

Schematic configuration diagram of engine-driven heat pump system using geothermal heat

Explanation of symbols

1: compressor 2: condenser 5: compression heat pump circuit 7: circulation pump 11: engine 21: hot water supply heat exchanger 23: buried heat exchanger 50: controller (an example of underground heat radiation operation means A)
51: Underground heat dissipation circuit 53: Temperature sensor X: Refrigerant R: Heat medium HW: Hot water JW: Jacket water C: Cold water H: Hot water G: Fuel 100: Engine-driven heat pump system

Claims (3)

Engine,
A compression heat pump circuit that uses shaft power of the engine as a power source of a compressor that compresses refrigerant;
An engine-driven heat pump system provided with underground heat radiation operation means capable of performing condensed heat release operation for releasing condensed heat generated in a condenser provided in the compression heat pump circuit into the ground,
An engine-driven heat pump system in which the underground heat radiation operation means is configured to be able to execute an exhaust heat release operation for releasing the exhaust heat of the engine into the ground. A heat storage tank for storing the exhaust heat of the engine;
The engine-driven heat pump system according to claim 1, wherein the underground heat radiation operation means executes the exhaust heat release operation when a heat storage amount of the heat storage tank is full.   The engine-driven heat pump system according to claim 1 or 2, wherein the underground heat radiation operation means is configured to be able to execute the condensation heat release operation and the exhaust heat release operation separately.

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