JPH0125977B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cold/hot fluid manufacturing apparatus in which a heat pump is driven by a compressor driven by a heat engine such as an engine.

This engine-driven heat pump can also partially recover the thermal energy possessed by combustion exhaust gas, so it is more energy efficient than an electric heat pump.

However, this heat pump has one major drawback.

That is, the conventional cold/hot fluid production apparatus equipped with a heat engine-driven heat pump has a drawback that the capacity control range during heating is narrow. The reason for this is that during heating, unlike during cooling, the exhaust heat from the heat engine is also added to the heating capacity as heat, so the heating capacity becomes considerably excessive compared to the cooling capacity. Therefore, in seasons when the heat load is not so large, the capacity can not be reduced by the capacity reduction device of a normal heat pump, and the minimum reduction capacity becomes large.

SUMMARY OF THE INVENTION In order to overcome these drawbacks, it is an object of the present invention to provide a cold and hot fluid manufacturing apparatus equipped with a heat engine-driven heat pump having a wide capacity control range.

The invention will now be explained with reference to examples.

Jacket portion 11 of engine 10 which is a heat engine
For example, cooling water is provided as a cooling fluid to flow through the cooling water path, and this cooling water path includes a cooling water heat recovery path that leads the cooling water to the cooling device 17 and heats the hot water in the cooler 17, and an air-cooled cooler 14. It is branched into a cooling water heat release path that guides the cooling water and releases the heat of the cooling water to the outside, and both paths can be switched by electromagnetic valves 15 and 16.

The combustion exhaust gas path of the engine 10 is a combustion exhaust gas heat recovery path that guides the combustion exhaust gas to the exhaust heat recovery device 19 to heat hot water, and then releases it to the outside from the hole 27 through the duct 25 and the upper chamber 26. The combustion exhaust gas is then branched into a combustion exhaust gas release path that is directly released to the outside, and both paths can be switched by a damper 20.

Of course, the solenoid valves 15 and 16 and the damper 20 can be switched between hot water production (heating) and cold water production (cooling), but in the present invention, load-related physical quantities are detected during hot water production and load control is performed. A control device (not shown) is provided to switch at least one of the electromagnetic valves 15, 16 and the damper 20 when the engine temperature is low to stop heat recovery using the hot water, that is, heating of the hot water using the cooling water of the engine 10 or the combustion exhaust gas. There is.

Next, the operation will be explained.

The heat pump cycle is similar to a normal electric air source heat pump.

That is, during summer cooling, the refrigerant flows from the compressor 1 → four-way valve 2 → outside air side heat exchanger 3, 3' (acts as a condenser) → check valve 4, 4' → receiver 5 → expansion valve 6 → load side The cold water is circulated in the order of heat exchanger 7 (acting as an evaporator) → four-way valve 2 → compressor 1, and the cold water is cooled in the load-side heat exchanger 7.
Types of compressors used include piston type, rotary type, and centrifugal type.

During heating, the four-way valve 2 is switched to change the refrigerant path, compressor 1 → four-way valve 2 → load-side heat exchanger 7 (acts as a condenser) → check valve 8 → receiver 5 → expansion valves 9, 9' →Outside air side heat exchanger 3
It circulates in the order of (acts as an evaporator) → four-way valve 2 → compressor 1, and hot water is heated in the load-side heat exchanger 7.

On the other hand, cooling of the engine 10 that drives the compressor 1 is performed as follows.

During cooling, cooling water is sent to the water jacket portion 11 of the engine 10 by a pump 12, and the engine 10 is cooled. The cooling water that cooled the engine 10 (a medium other than water may be used) passes through the valve 15 and is sent to the air-cooled cooling water cooler 14, where the heat is radiated. Also, during heating, the solenoid valves 15 and 16 are switched, and the cooling water is sent to the water-cooled cooling water cooler 17, and by heating the hot water for heating, the cooling water itself is cooled.

The three-way valve 13 is adjusted to keep the temperature of the cooling water sent to the jacket portion 11 constant. Cold and hot water is sent to this cold and hot water production device by a pump 18. During heating, the heat is first sent to the load-side heat exchanger 7 and heated, passes through the exhaust heat recovery device 19 → the water-cooled cooling water cooler 17, is further heated, and is supplied to the hot water load.

During cooling, solenoid valves 15, 16, switching damper 20
Since the cooling water is switched, the cooling water is only cooled by the load-side heat exchanger and simply passes through the other two heat exchange devices 19 and 17, and no heat is exchanged.

On the other hand, during cooling, the air-cooled cooling water cooler 14 operates to release heat from the engine jacket 11.
Since the fan 22 is being operated, the discharged gas is cooled by this air in the heat radiating section 23 of the exhaust gas duct facing the discharge section of the fan 22.

Further, during heating, the exhaust gas from the engine 10 heats hot water for heating in the exhaust heat recovery device 19, and the exhaust gas itself is cooled and sent to the silencer 24. Since the temperature of the exhaust gas at the exit from the exhaust heat recovery device 19 is low, the silencer 24 can be made of a normal sound absorbing material. The sound-reduced exhaust gas is in duct 2
5 to the upper chamber 26, and a number of holes 27 provided at the bottom of this upper chamber 26.
It is discharged to the air intake side of the heat exchanger on the outside air side.

Next, in the winter, as a defrosting method when frost forms on the outside air side heat exchanger 3, the solenoid valve 28 is opened, the solenoid valves 29, 29' are closed, and the blowers 30, 30' are stopped. When the solenoid valve 28 is opened, the liquid refrigerant flows into the auxiliary evaporator 31, where it is heated by hot water, evaporates, and is sucked into the compressor, so that the operation of the apparatus continues. Normally, when this day frost operation is entered, the heat pump's capacity decreases, so to prevent this, load-related physical quantities are detected and the engine speed is increased to prevent the heating capacity from decreasing. There is.

If the operation is continued in this state, warm air is discharged from the holes 27, so that the surface of the outside air side heat exchanger 3 is day-frosted. In addition, since the auxiliary evaporator 31 is operating, the engine output increases accordingly, and the amount of exhaust heat increases accordingly, so a certain amount of heating capacity is ensured, which has the advantage of preventing a decrease in the overall performance of the device. There is.

Furthermore, a method in which the exhaust gas heat radiation section 23 is located between the engine body and the exhaust heat recovery device 19 is also effective. In this case, the heat dissipation part can be placed at a relatively low position,
This also has the effect of making the entire device more compact.

Alternatively, the arrangement may be as follows: engine 10 -> heat radiating section 23 -> exhaust heat recovery device 19 -> silencer -> switching damper.

The above is a description of the operation of the device in a steady state. Next, the operation under partial load will be described.

If the heating load decreases and the rotational speed control of the engine 10 or the capacity control mechanism of the compressor 1 can no longer cope with the problem, one or more of the following measures may be taken.

(1) By opening the solenoid valve 28, the auxiliary evaporator 3
Activate 1.

(2) Switch the switching valves 15 and 16, operate the blower 22, and stop the heat recovery action of the exhaust heat from the jacket part 11. Note that when the outside temperature is low, it is not necessary to operate the blower 22.

(3) Switch the switching damper 20 to the direct release side where exhaust heat recovery is not performed.

The present invention can provide a heat engine-driven cold and hot fluid production device with a wide capacity control range by adjusting the heat recovery means accordingly when the load is small, and has extremely large practical effects. It is something that you have.

[Brief explanation of drawings]

The drawing is a flow diagram of an embodiment of the invention. 1... Compressor, 2... Four-way valve, 3, 3'... Outside air side heat exchanger, 4, 4'... Check valve, 5...
Receiver, 6...Expansion valve, 7...Load side heat exchanger, 8...Check valve, 9,9'...Expansion valve, 1
0... Engine, 11... Jacket part, 12...
...Pump, 13...Three-way valve, 14...Cooler, 1
5...Solenoid valve, 16...Solenoid valve, 17...Cooler, 18...Pump, 19...Exhaust heat recovery device, 2
0...damper, 21...silencer, 22...
Fan, 23...heat dissipation section, 24...silencer,
25...Duct, 26...Upper chamber, 27
... hole, 28 ... solenoid valve, 29, 29' ... solenoid valve, 30, 30' ... blower, 31 ... auxiliary evaporator, 32 ... soundproof box.

Claims (1)

[Claims] 1. A cooling fluid heat recovery path that includes a heat pump driven by a heat engine, which guides the cooling fluid of the heat engine to a hot fluid path and recovers heat with the hot fluid, and a cooling fluid heat release path that releases the heat of the cooling fluid to the outside. A cold and hot fluid that can be switched between a combustion exhaust gas heat recovery path that guides the combustion exhaust gas of the heat engine to the hot fluid path and recovers heat with the hot fluid, and a combustion exhaust gas release path that releases the combustion exhaust gas to the outside. In manufacturing equipment, control that detects load-related physical quantities during hot fluid production and switches at least one of the cooling fluid path and the combustion exhaust gas path to stop heat recovery using the hot fluid when the load is small based on the signal. A cold/hot fluid manufacturing device comprising: