JPS6326833B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a heat pump device that performs at least heating by driving a compressor using a heat engine powered by combustion energy such as city gas or kerosene. be.

[Prior art]

BACKGROUND ART In recent years, from the viewpoint of energy conservation, development of heat pump devices that perform heating using a heat pump using combustion energy such as city gas or kerosene has been active. This heat pump uses combustion energy to operate the engine, etc., which drives the heat pump compressor to perform heating, and the exhaust heat of the engine during heating can be used for heating, so it is better than an electric heat pump. It is energy saving.

[Problem that the invention seeks to solve]

However, in conventional engine-driven exhaust heat recovery heat pumps, when the outside air temperature is very low or when it snows, the evaporation temperature in the outside air side heat exchanger decreases, the specific volume of refrigerant gas increases significantly, and the refrigerant circulates. The amount of water may decrease drastically, the heating capacity may drop abnormally, and frost may form, making it unusable. In such a case, not only will the heat pump not be able to heat the load hot water, but the heat pump load will be small, making it impossible to rotate the engine at the rated speed, and even if only the engine were to rotate, there would be no load. Due to idling operation, the amount of exhaust heat also decreases, and in the end, the heating capacity is reduced not only by the decrease in the heat of the outside air that should be pumped, but also by the decrease in heat pump heating due to the heat pump not being able to operate, and the reduction in heat pump exhaust heat due to the heat pump being unable to operate. There was a problem in that the reduction in heat capacity combined with the reduction in heating capacity was significant.

In addition, as a countermeasure in the event that the outside temperature drops abnormally, even if the engine speed is simply increased, the suction pressure will drop extremely due to the increased suction capacity of the compressor, and the heat pump's suction pressure drop safety device will be activated. There was a problem that caused the machine to stop operating.

That is, when the outside air temperature is very low or when it snows, conventional heat pumps have an abnormally low capacity and can become almost unusable, making it necessary to operate a backup hot water boiler.

The present invention eliminates the drawbacks of the conventional ones, and
It is an object of the present invention to provide a heat pump device that maintains the same heating capacity as in normal times even at abnormally low temperatures without the need to use a hot water boiler or the like.

[Means for solving problems]

The first invention is a compressor driven by a heat engine,
A heat pump device comprising a heat pump including an outside air side heat exchanger, a load side heat exchanger, an expansion device, and a refrigerant path connecting these devices, and an exhaust heat recovery device that recovers exhaust heat from the heat engine,
a load fluid path that guides the load fluid to the exhaust heat recovery device and the load-side heat exchanger; an outside temperature detection device that directly or indirectly detects the outside temperature; and the outside temperature is below a predetermined abnormally low temperature. a refrigerant gas bypass device that bypasses the outside air side heat exchanger from the refrigerant gas and high pressure refrigerant gas path to a low pressure refrigerant path downstream of the outside air side heat exchanger; and a rotation speed control device that increases the maximum set rotation speed of the heat engine above the normal maximum set rotation speed when it is detected that the air temperature is below a predetermined abnormally low temperature. A second invention is a heat pump device comprising a compressor driven by a heat engine, an outside air side heat exchanger, a load side heat exchanger, an expansion device, and a refrigerant path connecting these devices; A heat pump device comprising: an exhaust heat recovery device for recovering exhaust heat from the heat pump device;
An outside temperature detection device that directly or indirectly detects the outside temperature, and when it is detected that the outside temperature is below a predetermined abnormally low temperature, refrigerant gas is transferred from the high pressure refrigerant gas path to outside air side heat exchange. bypass the device,
A refrigerant gas bypass device that guides the refrigerant to a low-pressure refrigerant path downstream of the outside air side heat exchanger, and a refrigerant gas bypass device that directs the refrigerant liquid from the high-pressure refrigerant path when it is detected that the outside temperature is below a predetermined abnormally low temperature. , a refrigerant liquid bypass device that bypasses an outside air side heat exchanger and guides the refrigerant to a low pressure refrigerant path downstream of the outside air side heat exchanger; and when it is detected that the outside air temperature is below a predetermined abnormally low temperature. The heat pump device further comprises a rotation speed control device that increases the maximum set rotation speed of the heat engine above the normal maximum set rotation speed.

〔Example〕

The present invention will be explained with reference to the drawings based on examples.
In the heat pump device shown in the drawing, 1 is a compressor, 3 is an outside air side heat exchanger, 7 is a load side heat exchanger, 9 is an expansion valve as an expansion device, and each device is connected by a refrigerant path to complete the heat pump. is formed.

The refrigerant path includes a refrigerant gas bypass path 31 that leads refrigerant gas from a high-pressure refrigerant gas path to a low-pressure refrigerant path downstream of the outside air-side heat exchanger 3 by bypassing the outside air-side heat exchanger 3, and a refrigerant gas bypass path 31 that leads refrigerant gas from a high-pressure refrigerant gas path to a low-pressure refrigerant path downstream of the outside air-side heat exchanger 3, and a refrigerant gas bypass path 31 that leads refrigerant gas from a high-pressure refrigerant gas path to a low-pressure refrigerant path downstream of the outside air-side heat exchanger 3. A refrigerant liquid bypass path 32 that bypasses the outside air side heat exchanger 3 from the liquid path and leads to a low pressure refrigerant path downstream of the outside air side heat exchanger 3 is provided, and each path 31, 3
2 is provided with bypass valves 27 and 28 that open each path 31 and 32 when it is detected that the outside temperature is below a predetermined abnormally low temperature. A refrigerant gas bypass device is configured, and a refrigerant liquid bypass path 32
and the bypass valve 28 constitute a refrigerant liquid bypass device. In this embodiment, an upper header 29 is provided in the low-pressure refrigerant path downstream of the outside air side heat exchanger 3, and the refrigerant path between the compressor 1 as a high-pressure refrigerant gas path and the load-side heat exchanger 7 is provided. and the upper header 29 are connected by a refrigerant gas bypass path 31 having a bypass valve 27, and a refrigerant liquid bypass path 32 having a bypass valve 28 is connected between the receiver 5 as a high-pressure refrigerant liquid path and the upper header 29. It is connected with Further, a four-way valve 2, an expansion valve 6, and check valves 4 and 8 are arranged in the refrigerant path to enable switching to cooling operation.

Reference numeral 10 denotes an engine used as a heat engine to drive the compressor 1, and an exhaust heat recovery device for recovering exhaust heat from the engine 10 is provided, for example, in the engine cooling water (a cooling fluid other than water may be used) route. A water-cooled cooling water cooler 16 and an exhaust gas heat recovery device 19 provided in the exhaust gas path are provided.

The engine cooling water path is a path in which the cooling water exiting the jacket part 11 is guided to a water-cooled cooling water cooler 16 during heating and to an air-cooled cooling water cooler 14 during cooling, and can be switched using three-way valves 13 and 15. There is. 12 is a cooling water pump, and 17 is a three-way valve for adjusting the temperature of cooling water sent to the jacket portion 11. The exhaust gas route includes an exhaust gas heat recovery device 19 and an exhaust gas duct 3 when heating the exhaust gas.
0, 22, 22'22'', and during cooling, the heat is directly released to the outside without being recovered, and a switching damper 20 is provided. 21 is a muffler, and 23 is a discharge hole.

24 is a soundproof box that houses the compressor 1, the engine 10, the exhaust gas heat recovery device 19, and the water-cooled cooling water cooler 16, and includes an air intake port 25 with a silencer,
A fan 26 is provided.

The load fluid path transports the load fluid from the load side heat exchanger 7 to the exhaust gas heat recovery device 19 and the water-cooled cooling water cooler 16.
It is provided so that it is returned to the load via the
18 is a pump.

Therefore, the normal heat pump cycle is similar to that of a general electric air source heat pump.
In other words, during summer cooling, the refrigerant flows through the compressor 1 → four-way valve 2 → outside air side heat exchanger 3 (operates as a condenser)
→ Check valve 4 → Receiver 5 → Expansion valve 6 → Load side heat exchanger 7 (operates as an evaporator) → Four-way valve 2 →
The cold water is circulated in the order of the compressor 1 and cooled in the load side heat exchanger 7.

During heating, the four-way valve 2 is switched to change the refrigerant route. Then, the refrigerant flows through the compressor 1 → four-way valve 2 → load side heat exchanger 7 (acts as a condenser) → check valve 8 → receiver 5 → expansion valve 9 → outside air side heat exchanger 3 (acts as an evaporator) → four-way The hot water is circulated in the order of the valve 2 and the compressor 1, and the hot water is heated in the load side heat exchanger 7.

On the other hand, the cycle on the engine 10 side is as follows. During cooling, the exhaust heat from the jacket section 11 is cooled by the air-cooled cooling water cooler 14. That is,
Cooling water that has cooled the jacket part 11 and is heated is sucked by the pump 12 and is sent to the air-cooled cooling water cooler 1.
4, where it is cooled. and three-way valve 1
3 and 15, it is again supplied to the jacket section 11.

On the other hand, after the exhaust gas from the engine 10 passes through the muffler 21, it is discharged directly into the outside air by the damper 20.

Therefore, the cold water cooled by the load-side heat exchanger 7 is transferred to the exhaust gas heat recovery device 19 and the water-cooled cooling water cooler 16.
There is no exchange of heat.

In addition, since the fan 26 is operated during cooling, the high temperature air inside the soundproof box 24 is ventilated, and the temperature inside the soundproof box 24 does not rise abnormally.

During heating, the three-way valves 13 and 15 are switched, and the exhaust heat from the engine 10 is used to heat the hot water. That is, the cooling water that has been heated by cooling the jacket section 11 is sucked into the water-cooled cooling water cooler 16 by the pump 12, where the hot water serving as the load fluid is heated and then discharged to the jacket section 11 again. On the other hand,
The damper 20 is switched, and the exhaust gas from the engine 10 is transferred to the exhaust gas heat recovery device 19 and the exhaust gas duct 3.
0, 20, 20', 20'' and is discharged to the outside air from the discharge hole 23.

Therefore, the hot water heated by the load-side heat exchanger 7 is transferred to the exhaust gas heat recovery device 19 and the water-cooled cooling water cooler 16.
It is further heated and subjected to hot water loading.

Note that during heating, since the outside air temperature is low, the temperature inside the soundproof box 24 does not rise much.

Furthermore, when it is detected that the outside temperature is below a predetermined abnormally low temperature during heating, the rotational speed of the engine 10 can be increased higher than the maximum set rotational speed during normal heating. I'm starting to be able to do it. In other words, the rotation speed control device is used to change the maximum engine rotation speed setting. For example, in order to change the maximum rotation speed setting, the rotation speed control device operates the position of a stopper that regulates the opening of the throttle valve, or controls the governor controller. The maximum set rotation speed of the engine 10 can be changed by changing the maximum value of the input voltage to the engine 10. This rotational speed control device switches the set value of the maximum rotational speed to a higher value in abnormal situations than in normal times.

Therefore, when the outside temperature is abnormally low during heating, the outside temperature thermostat as an outside temperature detection device is activated, and the signal is used to activate the rotation speed control device to adjust the maximum set rotation speed of the engine 10 to the normal setting. The rotation speed of the engine 10 is changed to be higher than the maximum set rotation speed to make the rotation speed of the engine 10 higher than the normal maximum set rotation speed. At the same time, the bypass valve 27,
28 can be opened. That is, the bypass valve 27 is opened and the high-pressure refrigerant gas is transferred to the refrigerant gas bypass path 3.
1 and is bypassed to the suction side of the compressor 1, preventing a drop in suction pressure and enabling operation of the heat pump.

Therefore, the rotational speed of the engine 10 is increased from normal, and the increased mechanical work of the compressor 1 is applied to the hot water through the load-side heat exchanger 7, and at the same time, the increased exhaust heat of the engine 10 is applied to the hot water. In this way, a decrease in heating capacity can be prevented.

Furthermore, when a refrigerant liquid bypass device is also used, this gas is caused by the refrigerant liquid flushed from the refrigerant liquid bypass path 32 to the upper header 29.
This will lower the refrigerant temperature and prevent deterioration.

As the outside temperature detection device, instead of the outside temperature thermostat that directly detects the outside temperature, a suction pressure switch of the compressor 1 and a thermostat that detects the evaporation temperature are used.
It may also be detected indirectly.

Since the above embodiment has the above-described configuration, when the outside air temperature is abnormally low, the input to the engine 10 can be increased without abnormally decreasing the suction pressure of the compressor 1, so that the engine 10 can be rotated. By increasing the number of compressor 1 and engine 10,
The engine-driven heat pump can be given a function similar to a hot water boiler by increasing the exhaust heat of the heat pump and heating the hot water by supplying the heat to the hot water, thereby eliminating the need to separately install an auxiliary boiler.

FIG. 2 is a heat flow diagram when the outside temperature is abnormally low. That is, although the amount of heated water in the load-side heat exchanger 7 decreases, the load on the engine 10 is ensured by the bypass valve 27 as a hot gas bypass valve and the bypass valve 28 as a liquid injection valve, so that the rotational speed decreases. The amount of work of the compressor 1 is increased by increasing the rotation speed of the engine 10 above the normal maximum set rotation speed by the action of the control device, and this is applied as heat to the hot water through the load-side heat exchanger 7, Further, since the jacket exhaust heat and the exhaust gas calorific value also increase in approximately proportion to the load on the engine 10, the heating capacity hardly decreases.

〔Effect of the invention〕

A first invention provides a heat pump comprising a compressor driven by a heat engine, an outside air side heat exchanger, a load side heat exchanger, an expansion device, and a refrigerant path connecting these devices; A heat pump device comprising: a load fluid path that guides a load fluid to the exhaust heat recovery device and the load-side heat exchanger; and an outside temperature that directly or indirectly detects the outside temperature. and a detection device, when it is detected that the outside temperature is below a predetermined abnormally low temperature, the refrigerant gas is bypassed from the outside air side heat exchanger from the high pressure refrigerant gas path, and from the outside air side heat exchanger. and a refrigerant gas bypass device that guides the heat engine to a downstream low-pressure refrigerant path, and when it is detected that the outside temperature is below a predetermined abnormally low temperature, the maximum set rotation speed of the heat engine is changed to the normal maximum set rotation speed. Since this heat pump device is characterized by being equipped with a rotation speed control device that increases the rotation speed, the heat pump can operate even when the outside air temperature is abnormally low. Heat equivalent to work and engine exhaust heat are given to hot water, heating capacity hardly decreases, and there is no need to use a hot water boiler. Further, in the second invention, by bypassing the refrigerant liquid, the temperature of the refrigerant is lowered and deterioration can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a flow diagram of an embodiment of the present invention, and FIG. 2 is a heat flow diagram of this embodiment when the outside temperature is abnormally low. 1...Compressor, 2...Four-way valve, 3...Outside air side heat exchanger, 4...Check valve, 5...Receiver,
6... Expansion valve, 7... Load side heat exchanger, 8... Check valve, 9... Expansion valve, 10... Engine, 1
1...Jacket part, 12...Pump, 13...
Three-way valve, 14... Air-cooled cooling water cooler, 15... Three-way valve, 16... Water-cooled water-cooled cooler, 17... Three-way valve, 18... Pump, 19... Exhaust gas heat recovery device, 20... Damper , 21...muffler, 2
2, 22', 22''...exhaust gas duct, 23...discharge hole, 24...soundproof box, 25...air supply port,
26...Fan, 27, 28...Bypass valve, 2
9... Upper header, 30... Exhaust gas duct, 3
1... Refrigerant gas bypass path, 32... Refrigerant liquid bypass path.

Claims (1)

[Scope of Claims] 1. A heat pump consisting of a compressor driven by a heat engine, an outside air side heat exchanger, a load side heat exchanger, an expansion device, and a refrigerant path connecting these devices;
A heat pump device comprising an exhaust heat recovery device that recovers exhaust heat from the heat engine, the load fluid path guiding a load fluid to the exhaust heat recovery device and the load side heat exchanger, an outside air temperature detection device that indirectly detects the outside air temperature; and when it is detected that the outside air temperature is below a predetermined abnormally low temperature, the refrigerant gas is bypassed through the outside air side heat exchanger from the high pressure refrigerant gas path; a refrigerant gas bypass device that guides the refrigerant to a low-pressure refrigerant path downstream of the outside air side heat exchanger; A rotation speed control device that increases the rotation speed above the normal maximum setting. A heat pump device characterized by comprising: 2. A heat pump consisting of a compressor driven by a heat engine, an outside air side heat exchanger, a load side heat exchanger, an expansion device, and a refrigerant path connecting these devices,
A heat pump device comprising an exhaust heat recovery device that recovers exhaust heat from the heat engine, the load fluid path guiding a load fluid to the exhaust heat recovery device and the load side heat exchanger, an outside air temperature detection device that indirectly detects the outside air temperature; and when it is detected that the outside air temperature is below a predetermined abnormally low temperature, the refrigerant gas is bypassed through the outside air side heat exchanger from the high pressure refrigerant gas path; a refrigerant gas bypass device that guides the refrigerant to a low-pressure refrigerant path downstream of the outside air side heat exchanger; , a refrigerant liquid bypass device that bypasses an outside air side heat exchanger and guides the refrigerant to a low pressure refrigerant path downstream of the outside air side heat exchanger; and when it is detected that the outside air temperature is below a predetermined abnormally low temperature. and a rotation speed control device for increasing the maximum set rotation speed of the heat engine above the normal maximum set rotation speed. A heat pump device characterized by comprising: